CN104661567A - Chair arm assembly - Google Patents

Abstract

A chair assembly includes: a four-bar linkage assembly including a first link, a second link, a third link, and a fourth link each pivotably coupled to one another such that the four-bar linkage assembly includes a an upper end adjustable between raised and lowered positions; and an armrest assembly adapted to support the arm of a seated user thereon and supported on the upper end of a four-bar linkage assembly; wherein the lower end of the four-bar linkage assembly extends from the arm The support structure is pivotally supported for pivotal movement such that the upper end of the four-bar linkage assembly is movable between a first position and a second position laterally outward of the first position.

Description

chair arm assembly

technical field

The present invention relates to a chair assembly, and more particularly to an office chair arm assembly which is vertically and horizontally adjustable and which includes a pivotally and linearly adjustable arm cap assembly.

Contents of the invention

One aspect of the present invention is to provide a chair assembly comprising a 4-link assembly comprising a first link member having a first end and a second end, a second link member having a first end and a second end, a second link member having a first end and a second end, Three link members, which have a first end, which is pivotally coupled to the first end of the first link member to rotate about a first pivot point, and a second end, which is pivotally coupled to the first The first end of two linkage members is to rotate about the second pivot point, and the fourth linkage member has a first end that is pivotally coupled to the second end of the first linkage member to rotate about the second pivot point. Three pivot points for rotation, and a second end that is pivotally coupled to the second end of the second linkage member for rotation about a fourth pivot point, wherein the 4-bar linkage assembly includes a lower end and an upper end that can be positioned at Adjusted between a raised position and a lowered position. The chair assembly also includes an armrest assembly adapted to support the seated user's arms thereon and is supported on the upper end of the 4-bar linkage assembly, wherein the lower end of the 4-bar linkage assembly is pivotally supported by the arm support structure , so as to pivotally move around the fifth pivot point, so that the upper end of the 4-bar linkage assembly can move between a first position and a second position, the second position being located laterally outward of the first position.

Another aspect of the present invention is to provide a chair assembly comprising a 4-link assembly comprising: a first link member with a first end, a second end, and a U-shaped cross-sectional configuration; a second linkage member having a first end, a second end, and a U-shaped cross-sectional configuration disposed along its length, and wherein the first linkage member and the second linkage member cooperate to An interior space extending longitudinally along the lengths of the first and second link members is formed; a third link member having a first end pivotally coupled to the first end of the first link member to rotate about the first end of the first link member a pivot point, and a second end, which is pivotally coupled to the first end of the second link member to rotate about the second pivot point; and a fourth link member, which has a first end, It is pivotally coupled to the second end of the first link member to rotate about the third pivot point, and the second end, it is pivotally coupled to the second end of the second link member to rotate about the fourth pivot point. The pivot point rotates; wherein the 4-bar linkage assembly includes lower and upper ends that are adjustable between a raised position and a lowered position. The chair assembly also includes an armrest assembly adapted to support an arm of a seated user thereon and supported on the upper end of the 4-bar linkage assembly, and a locking assembly including a first locking coupling having a first surface, and a second locking link having a plurality of teeth corresponding to a plurality of vertical positions of the 4-bar link between a raised position and a lowered position, wherein the first and second locking links are movable relative to each other movement between a locked position in which the first surface engages at least one of the plurality of teeth to prevent the 4-link from being adjusted between raised and lowered positions, and an unlocked position in which , the first surface and the plurality of teeth are spaced apart from one another, thereby allowing the 4-bar linkage to be adjusted between raised and lowered positions, and wherein at least a substantial portion of each of the first and second locking couplings is located within the interior space .

Yet another aspect of the present invention is to provide a chair assembly comprising: an arm support structure; an armrest assembly adapted to comfortably support the arm of a seated user thereon; a lower end of the structural support, and an upper end supporting the armrest assembly thereon, wherein the arm support assembly is adjustable between a vertically raised position and a vertically lowered position; and a locking assembly. The locking assembly includes: a first locking coupling having a first surface and at least one of a plurality of teeth; a second locking coupling having a first surface and another of a plurality of teeth and capable of being positioned in a locked position and moves between an unlocked position in which the first surface engages at least one of the plurality of teeth to prevent the arm support assembly from being adjusted between raised and lowered positions and in which the first the surface and the plurality of teeth are spaced apart from each other, thereby allowing the arm support assembly to be adjusted between raised and lowered positions; Move between two positions, in the first position, the first locking coupling is moved to the locking position by the actuator coupling, in the second position, the first locking coupling is moved to the unlocking position by the actuator coupling; and with the actuation The actuator coupling is operably coupled to an actuator member, wherein at least a portion of the actuator member is actuatable by a seated user, thereby allowing the user to move the actuator coupling between first and second positions.

Another aspect of the invention is an armrest assembly for an office chair. The armrest assembly includes an outer component having an upholstery mounted thereto, and an inner component configured to be secured to the structure of the office chair. The inner part has teeth disposed thereon. The armrest assembly also includes upper and lower members extending between the inner and outer members and pivotally interconnecting them to form a 4-bar linkage. The armrest assembly also includes a vertical adjustment lock assembly to lock the height of the upholstery relative to the interior components. The vertical adjustment lock assembly includes a movable release member, and an actuator member that displaces between locked and unlocked positions when the release member moves. The actuator member defines a base end. The vertical adjustment lock assembly also includes a movable locking member with teeth that selectively engage teeth on the inner member of the 4-link. A spring biases the actuator member towards the locked position and also biases the teeth of the pivotable locking member out of engagement with the teeth on the inner member of the 4-link. The base end of the actuator member moves into the first recess of the locking member to allow the teeth of the locking member to move out of engagement with the teeth of the inner member of the 4-linkage. The armrest assembly also includes a second lock with a locking second recess in the locking member that receives the end of the actuator member and prevents locking of the locking member when downward force is applied to the cushion. move.

Yet another aspect of the present invention is to provide a chair assembly comprising a seat support structure including a seat support surface configured to support a seated user thereon, including an arm for supporting a seated user thereon An armrest assembly of an upper arm support surface, and an arm support assembly having an upper end that supports the arm support assembly at a higher vertical height than a seat support surface, and a lower end that includes pivot bosses and selected pivot apertures one of the . The chair assembly also includes an arm support structure that includes the other of a pivot boss and a pivot aperture, wherein the pivot boss is received in the pivot aperture to pivotally support the arm support assembly about a pivot point in the Rotating between the first position and the second position, the pivot boss has a conical shape, and wherein the aperture has a conical shape that closely corresponds to the shape of the pivot boss.

Another aspect of the present invention is to provide a chair assembly comprising: an arm support assembly having an upper end and a lower end; an armrest assembly adapted to support an arm of a seated user thereon and supported by the arm support assembly and an arm support structure pivotally supporting the arm support assembly to pivotally move about a substantially vertical axis such that the upper end of the arm support assembly can be in a first position about the substantially vertical axis and a second position that is laterally outward of the first position. The chair also includes a seat support structure comprising a seat support surface configured to support a seated user thereon, wherein the seat support surface includes a longitudinal axis, and wherein the upper end of the arm support assembly is aligned with the longitudinal axis of the seat support surface The parallel axial movement is greater than or equal to about 22° outward, and wherein the upper end of the arm support assembly is greater than or equal to about 17° inward from the axis parallel to the longitudinal axis of the seat support surface.

These and other features, advantages, and objects of the present invention will be further understood and appreciated by those skilled in the art by referring to the following specification, claims, and drawings.

Description of drawings

Figure 1 is a front perspective view of a chair assembly embodying the present invention;

Figure 2 is a rear perspective view of the chair assembly;

Figure 3 is a side view of the chair assembly showing the chair assembly in a lowered position, and in phantom in a raised position, and showing the seat assembly in a retracted position and in phantom in an extended position;

Figure 4 is a side view of the chair assembly showing the chair assembly in an upright position with a reclined position shown in phantom;

Figure 5 is an exploded view of the seat assembly;

Figure 6 is an enlarged perspective view of the chair assembly with a portion of the seat assembly removed to show the spring support assembly;

Figure 7 is a front perspective view of the backrest assembly;

Figure 8 is a side view of the backrest assembly;

Figure 9A is an exploded front perspective view of the backrest assembly;

Figure 9B is an exploded rear perspective view of the backrest assembly;

Figure 10 is an enlarged perspective view of area X of Figure 9A;

Figure 11 is an enlarged perspective view of area XI of Figure 2;

Figure 12 is a sectional view of the upper backrest pivot assembly along line XXII-XXII of Figure 7;

Figure 13A is an exploded rear perspective view of the upper back pivot assembly;

Figure 13B is an exploded front perspective view of the upper back pivot assembly;

Figure 14 is an enlarged perspective view of area XIV of Figure 9B;

Figure 15A is an enlarged perspective view of a comfort component and a lumbar support assembly;

Figure 15B is a rear perspective view of the comfort component and lumbar assembly;

Figure 16A is a front perspective view of a pawl assembly;

Figure 16B is a rear perspective view of the pawl assembly;

Fig. 17 is a partial sectional perspective view along line XVIII-XVIII of Fig. 15B;

Figure 18A is a perspective view of a backrest assembly with a portion of the comfort component cut away;

Figure 18B is an exploded perspective view of a portion of the backrest assembly;

Figure 19 is a perspective view of a control input assembly supporting the seat support board thereon;

Figure 20 is a perspective view of the control input assembly with certain elements removed to show its interior;

Figure 21 is an exploded view of the control input assembly;

Figure 22 is a side view of the control input assembly;

Figure 23A is a front perspective view of a back support structure;

Figure 23B is an exploded perspective view of the back support structure;

Figure 24 is a side view of the chair assembly showing its various pivot points;

Fig. 25 is a side perspective view of the control assembly showing a plurality of pivot points associated therewith;

Figure 26 is a cross-sectional view of the chair showing the backrest in the upright position with the lumbar adjustment set at a neutral setting;

Figure 27 is a cross-sectional view of a chair showing the backrest in an upright position with the lumbar portion set to a straight configuration;

Figure 28 is a cross-sectional view of a chair showing the back recline with the lumbar adjusted to a neutral position;

Figure 29 is a cross-sectional view of the chair in the reclined position with the lumbar adjusted to a straight configuration;

Figure 29A is a cross-sectional view of a chair showing the reclining backrest with the lumbar portion of the shell set to maximum arc;

Figure 30A is an exploded view of a moment arm displacement assembly;

Figure 30B is an exploded view of the moment arm displacement drive assembly;

Figure 31 is a cross-sectional perspective view of a moment arm displacement assembly;

Figure 32 is a top plan view of a plurality of control linkages;

33A is a side perspective view of the control assembly with the moment arm displacement member in the low tension position and the chair assembly in the upright position;

Figure 33B is a side perspective view of the control assembly with the moment arm displacement member in the low tension position and the chair assembly in the reclined position;

34A is a side perspective view of the control assembly with the moment arm displacement in the high tension position and the chair assembly in the upright position;

Figure 34B is a side perspective view of the control assembly with the moment arm displacement member in the high tension position and the chair assembly in the reclined position;

Figure 35 is a graph of torque versus caster at low and high tension settings;

Figure 36 is a perspective view of a direct drive assembly with the seat support plate exploded therefrom;

Figure 37 is an exploded perspective view of the direct drive assembly;

Figure 38 is a perspective view of a vertical height control assembly;

Figure 39 is a side view of the vertical height control assembly;

Figure 40 is a side view of the vertical height control assembly;

Figure 41 is a front elevation view in section of the first input control assembly;

Figure 42A is an exploded view of a control input assembly;

Figure 42B is an enlarged perspective view of the clutch member of the first control input assembly;

Figure 42C is an exploded view of the control input assembly;

Figure 43 is a side perspective view of the variable backrest control assembly;

Figure 44 is a perspective view of an arm assembly;

Figure 45 is an exploded perspective view of the arm assembly;

Figure 46 is a side view of the arm assembly in a raised position, with the lowered position shown in phantom;

Figure 47 is a partial cross-sectional view of an arm assembly;

Figure 48 is a top plan view of the chair assembly showing the arm assembly in an in-line position and in phantom in an angled position;

Figure 49 is an isometric view of the arm assembly including a vertical height adjustment lock;

Figure 50 is an isometric view of the arm assembly including a vertical height adjustment lock;

Figure 51 is an isometric view of the arm assembly including a vertical height adjustment lock;

Fig. 52 is a top plan view of the chair assembly showing the armrest assembly in an in-line position, and in phantom in a rotated position, and in a retracted position, and in phantom in a deployed position;

Figure 53 is an exploded perspective view of the armrest assembly;

Figure 54 is a cross-sectional view of the armrest assembly;

Figure 55 is a perspective view of a chair assembly;

Figure 56 is a front elevational view of the chair assembly;

Figure 57 is a first side view of the chair assembly;

Figure 58 is a second side view of the chair assembly;

Figure 59 is a rear view of the chair assembly;

Figure 60 is a top plan view of the chair assembly;

Figure 61 is a bottom plan view of the chair assembly;

Figure 62 is a perspective view of an arm assembly;

Figure 63 is a front elevational view of the arm assembly;

Figure 64 is a first side view of the arm assembly;

Figure 65 is a second side view of the arm assembly;

Figure 66 is a rear side view of the arm assembly;

Figure 67 is a top plan view of the arm assembly; and

Figure 68 is a bottom plan view of the arm assembly.

Detailed ways

For the purposes described herein, the terms "upper", "lower", "right", "left", "rear", "front", "vertical", "horizontal" and their derivatives shall refer to Oriented invention. However, it is to be understood that the invention may assume various alternative orientations and step sequences unless expressly stated to the contrary. It is also to be understood that the particular apparatus and processes shown in the drawings, and described in the following specification, are exemplary embodiments of the inventive concepts defined by the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless expressly stated as such in the claims. Various elements of the embodiments disclosed herein may be described as being operably coupled to each other, including elements coupled directly or indirectly to each other. Furthermore, the term "chair" as used herein encompasses a variety of seating arrangements including office chairs, automotive seating, home seating, stadium seating, theater seating, and the like.

Reference numeral 10 (Figs. 1 and 2) generally designates a chair assembly embodying the present invention. In the illustrated example, the chair assembly 10 includes a caster base assembly 12 abutting a supported floor surface 13, a control or support assembly 14 supported by the caster base assembly 12, each operatively connected to the control assembly. 14 coupled seat assembly 16 and back assembly 18, and a pair of arm assemblies 20. Control assembly 14 (FIG. 3) is operably coupled to base assembly 12 such that the seat assembly 16, back assembly 18 and arm assembly 20 are vertically adjustable between a fully lowered position A and a fully raised position B , and is pivoted in direction 22 about a vertical axis 21 . The seat assembly 16 is operably coupled to the control assembly 14 such that the seat assembly 16 is longitudinally adjustable between a fully retracted position C and a fully deployed position D relative to the control assembly 14 . The seat assembly 16 (FIG. 4) and the back assembly 18 are operatively coupled to the control assembly 14 and to each other so that the back assembly 18 is movable between a fully upright position E and a fully reclined position F, and further The seat assembly 16 is movable between a fully upright position G and a fully reclined position H, which respectively correspond to a fully upright position E and a fully reclined position F of the backrest assembly 18 .

Base assembly 12 includes a plurality of pedestal arms 24 that extend radially and are spaced from each other about a hollow central post 26 that receives a pneumatic cylinder 28 therein. Each pedestal arm 24 is supported above the floor surface 13 by an associated caster assembly 30 . Although the base assembly 12 is shown as comprising a multi-armed pedestal assembly, it is noted herein that other suitable support structures may be used, including but not limited to fixed posts, multi-leg arrangements, vehicle seat support assemblies, and the like.

The seat assembly 16 (FIG. 5) includes a relatively rigid seat support panel 32 having: a front edge 34; a rear edge 36; and a pair of C-shaped rails 38 defining the side edges of the seat support panel 32 and Extends between leading edge 34 and trailing edge 36 . Seat assembly 16 also includes a flexible, resilient seat outer shell 40 having a pair of upturned side portions 42 and an upturned rear portion 44 that cooperate to form an upwardly disposed generally concave shape. . In the illustrated example, the seat shell 40 is constructed of a relatively pliable material such as thermoplastic elastomer (TPE). In assembly, the seat outer shell 40 is secured and sandwiched between the seat support plate 32 and a plastic, flexible, resilient seat pan 46 secured to the seat support plate 32 by a plurality of mechanical fasteners. The seat pan 46 includes a front edge 48, a rear edge 50, side edges 52 extending between the front edge 48 and the rear edge 50, a top surface 54 and a bottom surface 56 that cooperate to form an upwardly disposed generally concave shape. In the illustrated example, the seat pan 46 includes a plurality of longitudinally extending slots 58 extending forwardly from the rear edge 50 . The slots 58 interfit therebetween to define a plurality of fingers 60, each finger 60 being individually pliable and resilient. The seat pan 46 also includes a plurality of transversely oriented elongated apertures 62 located adjacent the front edge 48 . The apertures 62 cooperate to increase the overall bendability of the seat pan 46 in their area, and specifically allow a forward portion 64 of the seat pan 46 to flex in a vertical direction 66 relative to a rearward portion 68 of the seat pan 46, as discussed further below. of. The seat assembly 16 also includes a foam upholstery member 70 resting on the top surface 54 of the seat pan 46 and sunken within the seat outer shell 40, a fabric seat cover 72 (FIGS. 1 and 2), and an upper surface 76 of the upholstery member 70. . A spring support assembly 78 ( FIGS. 5 and 6 ) is secured to the seat assembly 16 and is adapted to flexibly support the front portion 64 of the seat pan 46 to bend in the vertical direction 66 . In the illustrated example, the spring support assembly 78 includes a support housing 80 comprising foam and having side portions 82 defining an upwardly concave arcuate shape. The spring support assembly 78 also includes a relatively rigid attachment member 84 extending laterally between the side portions 82 of the support housing 80 and positioned between the support housing 80 and the front portion 64 of the seat pan 46 . A plurality of mechanical fasteners 86 secure the support housing 80 and the attachment member 84 to the front portion 64 of the seat pan 46 . The spring support assembly 78 also includes a pair of cantilever springs 88 each having a distal end 90 received through a corresponding aperture 92 of the attachment member 84, and a proximal end 94 secured to the seat support plate 32 such that each cantilever spring Distal end 90 of 88 may bend in vertical direction 66 . A pair of linear bearings 96 are fixedly attached to the attachment member 84 and aligned with the apertures 92 thereof such that the linear bearings 96 slidably receive the distal end 90 of a corresponding cantilever spring 88 . In operation, the cantilevered springs 88 cooperate to allow the front portion 64 of the seat pan 46, and more generally the seat, to The entire front portion of the assembly 16 is curved in a vertical direction 66 .

The back assembly 18 ( FIGS. 7-9B ) includes a back frame assembly 98 and a back support assembly 99 supported thereby. The back frame assembly 98 generally comprises a substantially rigid material, such as metal, and includes a transversely extending top frame portion 100, a transversely extending bottom frame portion 102, and a pair of curved side frame portions 104, which Extending between and cooperating with top frame portion 100 and bottom frame portion 102 is an opening 106 having a relatively large upper dimension 108 and a relatively narrow lower dimension 110 .

The back assembly 18 also includes a pliable resilient plastic back shell 112 having an upper portion 114, a lower portion 116, a pair of side edges 118 extending between the upper portion 114 and the lower portion 116, a forward surface 120 and A rearward facing surface 122 wherein upper portion 114 is generally wider than lower portion 116 and lower portion 116 tapers downwardly to generally follow the configuration of the rear elevation of frame assembly 98 . A lower reinforcement member 115 is attached to hooks 117 of a lower portion 116 of the back shell 112 (FIG. 9A). The reinforcement member 115 includes a plurality of protrusions 113 that engage reinforcement ribs 134 to prevent side-to-side movement of the lower reinforcement member 115 relative to the back shell 112 . As discussed below, the reinforcement member 115 pivotably interconnects the back control link 342 ( FIG. 26 ) and the lower portion 116 of the back shell 112 at a pivot point or axis 346 .

The back shell 112 also includes a plurality of integrally molded, forwardly and upwardly extending hooks 124 (FIG. 10) spaced from each other about the perimeter of the upper portion 114 of the back shell. A central or lumbar portion 126 is positioned vertically between the upper portion 114 and the lower portion 116 of the back shell 112 and includes a plurality of transversely extending slots 128 that cooperate to form a plurality of transversely extending ribs 130 therebetween. The slots 128 cooperate to provide additional flexibility to the back shell 112 at their location. A pair of transverse ribs 130 cooperates with a vertically extending rib 132 integrally formed with the former and located at approximately the transverse midpoint of the former. As the backrest assembly 18 is moved from the upright position E to the reclined position F as described below, the vertical ribs 132 act to tie the transverse ribs 130 together and reduce the Vertical expansion between the latter. The back shell 112 also includes a plurality of transversely spaced reinforcement ribs 134 extending longitudinally along the vertical length of the back shell 112 between the lower portion 116 and the middle portion 126 . Note here that the depth of each rib 134 increases from the middle portion 126 along each rib 134 such that the overall rigidity of the back shell 112 increases from the middle portion 126 to the lower portion 116 along the length of the rib.

The back shell 112 also includes a pair of rearwardly extending, integrally molded pivot bosses 138 which form part of an upper back pivot assembly 140 . Back pivot assembly 140 ( FIGS. 11-13B ) includes pivot bosses 138 of back shell 112 , a pair of cover members 142 surrounding respective pivot bosses 138 , a track member 144 and a mechanical fastening assembly 146 . Each pivot boss 138 includes a pair of side walls 148 and a rearwardly concave seating surface 150 having a vertically elongated pivot slot 152 extending therethrough. Each cover member 142 is shaped to closely receive a corresponding pivot boss 138, and includes a plurality of side walls 154 corresponding to the side walls 148, and a rearwardly concave bearing surface 156 including A vertically elongated pivot slot 143 is adapted to align with the slot 152 of the corresponding pivot boss 138 . The track member 144 includes a central portion 158 extending laterally along and abutting the top frame portion 100 of the back frame assembly 98 and a pair of arcuate bearing surfaces 160 at ends thereof. In particular, the central portion 158 includes a first portion 162 and a second portion 164 , wherein the first portion 162 abuts the front surface of the top frame portion 100 and the second portion 164 abuts the top surface of the top frame portion 100 . Each bearing surface 160 includes an aperture 166 extending therethrough that aligns with a corresponding sleeve member 168 integral with the back frame assembly 98 .

In assembly, the cover member 142 is positioned about the corresponding pivot boss 138 of the back shell 112 and is operably positioned between the back shell 112 and the track member 144 such that the bearing surface 156 is sandwiched by the corresponding pivot boss. Between the seating surface 150 of the boss 138 and a bearing surface 160 . The mechanical fastening assemblies 146 each include a bolt 172 that secures the rounded abutment surface 174 of the bearing washer 176 into sliding engagement with the inner surface 178 of the corresponding pivot boss 138 and with the corresponding inner surface 178 of the back shell 112. The threaded engagement of the sleeve member 168. In operation, upper back pivot assembly 140 allows back support assembly 99 to pivot relative to back frame assembly about pivot axis 182 ( FIG. 7 ) in direction 180 ( FIG. 8 ).

The back support assembly 99 ( FIGS. 9A and 9B ) also includes a flexibly resilient comfort member 184 ( FIGS. 15A and 15B ) that attaches to the back shell 112 and slidably supports a lumbar support assembly 186 . The comfort component 184 includes an upper portion 188, a lower portion 190, a pair of side portions 192, a front surface 193, and a rear surface 195, wherein the upper portion 188, the lower portion 190, and the side portions 192 cooperate to form an aperture 194 that receives the lumbar support. Component 186 is therein. As best shown in FIGS. 9B and 14 , comfort component 184 includes a plurality of box-shaped coupling members 196 spaced from one another about the perimeter of upper portion 188 and extending rearwardly from rear surface 195 . Each box coupling 196 includes a pair of side walls 198 and a top wall 200 that cooperate to define an interior space 202 . A bar 204 extends between side walls 198 and is spaced from rear surface 195 . When assembled, the comfort component 184 ( FIGS. 12-14 ) is secured to the back shell 112 by aligning and vertically inserting the hooks 124 of the back shell 112 into the interior space 202 of each box-shaped coupling 196 , until the hook 124 engages the corresponding rod 204 . Note here that the front surface 120 of the back shell 112 and the rear surface 195 of the comfort component 184 are free of holes or apertures near the hooks 124 and box coupling 196 to provide a smooth front surface 193 and increased Comfort for the seated user.

The comfort component 184 (FIGS. 15A and 15B) includes an integrally molded, longitudinally extending sleeve 206 extending rearwardly from the rear surface 195 and having a rectangular cross-sectional configuration. The lumbar support assembly 186 includes a forwardly laterally concave and forwardly vertically convex, pliable, resilient body portion 208 and an integral support portion 210 extending upwardly from the body portion 208 . In the illustrated example, the body portion 208 is shaped such that it tapers vertically along its height such that it generally follows the contour and shape of the aperture 194 of the comfort component 184 . Support portion 210 is slidably received within sleeve 206 of comfort component 184 such that lumbar support assembly 186 is vertically adjustable between a fully lowered position I and a fully raised position J relative to the remainder of back support assembly 99. between. The detent member 212 selectively engages a plurality of apertures 214 spaced from one another along the length of the support portion 210 to releasably secure the lumbar support assembly 186 at a selected position between the fully lowered position I and the fully raised position J. in vertical position. The pawl member 212 ( FIGS. 16 a and 16 b ) includes a housing portion 216 having engagement tabs 218 at an end thereof and offset rearwardly from an outer surface 220 of the housing portion 216 . A flexibly resilient finger 222 is centrally disposed within housing portion 216 and includes a rearwardly extending detent 224 .

When assembled, the detent member 212 ( FIG. 17 ) is positioned within the aperture 226 in the upper portion 188 of the comfort member 184 such that the outer surface 220 of the housing portion 216 of the detent member 212 is in contact with the front surface 193 of the comfort member 184 . coplanar, and such that the engagement tab 218 of the shell portion 216 abuts the rear surface 195 of the comfort component 184 . The support portion 210 of the lumbar support assembly 186 is then positioned within the sleeve 206 of the comfort component 184 such that the sleeve 206 can slide therein and the detent 224 is selectively engageable with the aperture 214, thereby allowing the user to optimize the reclining position. The position of the lumbar assembly 186 relative to the integral back support assembly 99 . Specifically, the main body portion 208 of the lumbar support assembly 186 includes a pair of outwardly extending, integral handle portions 251 ( FIGS. 18A and 18B ), each having a C-shaped cross-sectional configuration that defines a channel 253 therein through which the The lane surrounds and guides along corresponding side edges 192 of the comfort part 184 and side edges 118 of the backrest shell 112 .

In operation, the user adjusts the position of the lumbar support assembly 186 relative to the back shell 112 by grasping one or both of the handle portions 251 and sliding the handle assembly 251 in a vertical direction along the comfort component 184 and the back shell 112. Relative vertical position. A stop tab 228 is integrally formed within the distal end 230 and is offset therefrom to engage the end wall of the sleeve 206 of the comfort component 184 to limit the movement of the support portion 210 of the lumbar support assembly 186 relative to the comfort component 184. The vertical downward travel of the cannula 206 .

The back assembly 99 (FIGS. 9A and 9B) also includes an upholstery member 252 having an upper portion 254 and a lower portion 256, wherein the lower portion 256 tapers along its vertical length to correspond to the overall shape and taper of the back shell 112 and comfort member 184.

Seat assembly 16 and back assembly 18 are operably coupled to and controlled by control assembly 14 ( FIG. 19 ) and control input assembly 260 . Control assembly 14 (FIGS. 20-22) includes a housing or base structure or ground structure 262 that includes a front wall 264, a rear wall 266, a pair of side walls 268, and a bottom wall 270 that are integrally formed with one another and cooperate to form An upwardly open interior space 272 . Bottom wall 270 includes an aperture 273 centrally located therein for passing cylinder assembly 28 (FIG. 3) therethrough to receive it, as described below. The base structure 262 further defines an upper and forward pivot point 274, a lower and forward pivot point 276, and an upper and rearward pivot point 278, wherein the control assembly 14 also includes a seat support that supports the seat assembly 16. Structure 282. In the illustrated example, seat support structure 282 has a generally U-shaped plan configuration that includes a pair of forwardly extending arm portions 284 that each include a forwardly located pivot aperture 286 that passes through the pivot axis. Rod 288 is pivotally secured to base structure 262 for pivotal movement about upper and forward pivot point 274 . The seat support structure 282 also includes a rear portion 290 that extends laterally between the arm portions 284 and cooperates therewith to form an interior volume 292 within which the base structure 262 is received. Rear portion 290 includes a pair of rearwardly extending arm mounting portions 294 to which arm assembly 20 is attached as described below. Seat support structure 282 also includes control input assembly mounting portion 296 to which control input assembly 260 is mounted. Seat support structure 282 also includes a pair of bushing assemblies 298 that cooperate to define pivot point 300 .

The control assembly 14 also includes a backrest support structure 302 having a generally U-shaped plan configuration and including a pair of forwardly extending arm portions 304 each including a pivot aperture 305 and pivotable by a pivot shaft 307 Rotationally coupled to the base structure 262 such that the back support structure 302 pivots about the pivot point 276 below and forward. The back support structure 302 includes a rear portion 308 that cooperates with the arm portion 304 to define an interior volume 310 that receives the base structure 262 therein. The back support structure 302 also includes a pair of pivot apertures 312 disposed along its length that cooperate to define a pivot point 314 . Note here that in some cases at least a portion of the back frame assembly 98 may be included as part of the back support structure 302 .

Control assembly 14 also includes a plurality of control linkages 316 each having a first end 318 pivotally coupled to seat support structure 282 by a pair of pivot pins 321 for pivoting about pivot point 300, and a pair of pivot pins 321 for pivoting about pivot point 300. The pivot pin 324 is pivotally coupled to a corresponding pivot aperture 312 of the back support structure 302 to pivot the second end 322 about the pivot point 314 . In operation, control linkage 316 controls the movement of seat support structure 282 relative to back support structure 302, specifically the rate of recline of the former relative to the latter, as the chair assembly is moved to the reclined position, as described below.

As best shown in FIGS. 23A and 23B , the bottom frame portion 102 of the back frame assembly 98 is configured to connect to the back support structure 302 via a quick connect device 326 . Each arm portion 304 of the back support structure 302 includes a mounting aperture 328 at a proximal end 330 thereof. In the illustrated example, the quick connect device 326 includes the configuration of the bottom frame portion 102 of the back frame assembly 98 to include a pair of forwardly extending coupler portions 332 that cooperate to define a channel 334 therebetween. , the channel 334 receives the proximal end 330 of the arm portion 304 and the rear portion 308 therein. Each coupler portion 332 includes a downwardly extending sleeve 336 that is aligned with and received by a corresponding aperture 328 . A mechanical fastener, such as screw 338 , is then threaded into the threads of sleeve 336 , thereby allowing quick connection of back frame assembly 98 to control assembly 14 .

As shown most clearly in FIG. 24 , base structure 262 , seat support structure 282 , back support structure 302 and control linkage 316 cooperate to form a 4-bar linkage assembly that supports seat assembly 16 , back assembly 18 and arm assembly 20 . For ease of reference, the relevant pivot assemblies associated with the 4-bar linkage assembly of the control assembly 14 are referred to as follows: The upper and forward pivot point 274 between the base structure 262 and the base support structure 282 is referred to as the first Pivot point 274; between base structure 262 and back support structure 302 pivot point 276 below and forward is referred to as second pivot point 276; between first end 318 of control link 316 and seat support structure 282 The pivot point 300 between is referred to as the third pivot point 300; and, the pivot point 314 between the second end 322 of the control linkage 316 and the back support structure 302 is referred to as the fourth pivot point 314. In addition, FIG. 24 shows in dashed lines the components of the chair assembly 10 in the reclined position, wherein the reference numerals of the chair in the reclined position are indicated by "'".

In operation, the 4-bar linkage assembly of the control assembly 14 cooperates to recline the seat assembly 16 from the upright position G to the reclined position H when the backrest assembly 184 is moved from the upright position E to the reclined position F, wherein the positions E and F The upper and lower representations in FIG. 24 show that the upper and lower portions of the backrest assembly 18 recline as a single piece. Specifically, control linkage 316 is configured and coupled to seat support structure 282 and back support structure 302 such that when back support structure 302 pivots about second pivot point 276, seat support structure 282 pivots about first pivot point 274 change. Preferably, the seat support structure 302 rotates about the first pivot point 274 at a rate that is between about 1/3 and about 2/3 of the rate at which the back support structure 302 rotates about the second pivot point 276, more preferably the seat support structure 302 The rate at which the structure rotates about the first pivot point 274 is about half the rate at which the back support structure 302 rotates about the second pivot point 276, and most preferably when the backrest assembly 18 reclines from the fully upright position E to the angle γ , which is about 18°, to the fully reclined position F, the seat assembly 16 reclines from the fully upright position G to an angle β, which is about 9°, to the fully reclined position H.

As shown most clearly in FIG. 24 , the first pivot point 274 is above and in front of the second pivot point 276 when the chair assembly 10 is in the fully upright position or the fully reclined position because the seat assembly The base structure 262 remains fixed relative to the supporting floor surface 13 while the 10 is tilted back. The third pivot point 300 remains behind the first pivot point 274 and below its relative vertical height throughout the reclining motion of the chair assembly 10 . It is further noted here that throughout the reclining movement of the chair assembly 10, the distance between the first pivot point 274 and the second pivot point 276 remains greater than the distance between the third pivot point 300 and the fourth pivot point 314. distance. As shown most clearly in Figure 25, a longitudinally extending central axis 340 of the control linkage 316 forms an acute angle α with the seat support structure 282 when the chair assembly 10 is in the fully upright position, and when the chair assembly 10 is in the fully reclined position , they form an acute angle α'. It is noted here that the central axis 340 of the control linkage 316 will not rotate beyond normal alignment with the seat support structure 282 when the chair assembly 10 is moved between its fully upright and fully reclined positions.

With further reference to FIG. 26 , the back control link 342 includes a front end that is pivotally connected to the seat support structure 282 at a fifth pivot point 344 . The rear end 345 of the back control link 342 is connected to the lower portion 116 of the back shell 112 at a sixth pivot point 346 . The sixth pivot point 346 is optional, and the back control link 342 and the back shell 112 may also be rigidly secured to each other. Additionally, the pivot point 346 may include a stop that limits rotation of the back control link 342 relative to the back housing 112 in the first and/or second rotational directions. For example, referring to FIG. 26 , the pivot point 346 may include a stop that allows the lower portion 116 of the back shell 112 to rotate clockwise relative to the control linkage 342 . The above configuration allows the lumbar to become flatter if a rearward/horizontal force tending to reduce dimension D1 is applied to the lumbar portion of the back shell 112 . However, the stop may be configured to prevent rotation of the lower portion 116 of the back housing 112 in a counterclockwise direction relative to the control linkage 342 ( FIG. 26 ). This causes the linkage 342 and the lower portion 116 of the back shell 112 to rotate at the same angular rate as the back assembly 18 when the user reclines in the chair by pushing on the upper portion of the back assembly 18 .

A cam link 350 is also pivotally connected to the seat support structure 282 for rotation about a pivot point or axis 344 . The cam link 350 has a curved lower cam surface 352 that slidably engages an upwardly facing cam surface 354 formed in the back support structure 302 . A pair of torsion springs 356 (see also FIGS. 18A and 18B ) tend to increase the angle The backrest control link 342 and the cam link 350 are rotatably biased in the manner (FIG. 26). The torsion springs 356 create a force that tends to rotate the control link 342 in a counterclockwise direction (FIG. 26) and at the same time turn the cam link 350 in a clockwise direction (FIG. 26). Accordingly, the torsion springs 356 tend to increase the angle between the back control linkage 342 and the cam linkage 350 A stop 348 on the seat support structure 282 limits counterclockwise rotation of the back control linkage 342 to the position shown in FIG. 26 . This force may also bias the control linkage 342 into the stop in a counterclockwise direction.

As discussed above, the back shell 112 is pliable, especially compared to the rigid back frame structure 98 . Also as discussed above, the back frame structure 98 is rigidly connected to the back support structure 302 and thus pivots with the back support structure 302 . The force generated by the torsion spring 356 urges the lower portion 116 of the back shell 112 upward. Also as discussed above, the slots 128 in the back shell structure 112 create additional flexibility in the lumbar support portion 126 of the back shell 112 . The force generated by the torsion spring 356 also tends to cause the lumbar portion 126 of the back shell 112 to flex forward so that the lumbar portion 126 has a greater curvature than the area adjacent to the lumbar portion 126 .

As discussed above, the position of the lumbar assembly 186 is vertically adjustable. Vertical adjustment of the lumbar assembly 186 also adjusts the way the back shell 112 bends/bends during reclining of the chair back. In FIG. 26, the lumbar assembly 186 is adjusted to an intermediate or neutral position, so that the curvature of the lumbar portion 126 of the back shell 112 is also intermediate or neutral. With further reference to Figure 27, if the vertical position of the lumbar support assembly 186 is adjusted, the angle is reduced, and the curvature of the waist region 126 is reduced. As shown in Figure 27, this also results in the angle becomes larger, and the overall shape of the back shell 112 becomes relatively straight.

With further reference to FIG. 28 , if the height of the lumbar assembly 186 is set at an intermediate level (i.e., as in FIG. 26 ), and a user leans back, then by the linkages and structures 262, 282, 302, 316 and the pivot points The 4-bar linkage defined by 274, 276, 300, 314 will be moved from the configuration of Fig. 26 to the configuration of Fig. 28 (as described above). This in turn results in an increased distance between pivot point 344 and cam surface 354 . This results in angular Increased from about 49.5° (FIG. 26) to about 59.9° (FIG. 28). When the spring rotates toward the open position, part of the energy stored in the spring is transferred to the back shell 112 , so that the curvature of the lumbar portion 116 of the back shell 112 becomes larger. In this manner, the back control linkage 342, cam linkage 350 and torsion spring 356 provide a greater curvature to the lumbar region 116 to reduce the curvature of the user's back as the user leans back in the chair.

Furthermore, the distance D between the lumbar region 242 and the seat 16 increases from 174 mm to 234 mm when the chair is tilted from the position of FIG. 26 to the position of FIG. 28 . As the backrest is tilted from the position of FIG. 26 to the position of FIG. 28 , the dimension D1 between the lumbar region 126 of the back shell 112 and the back frame structure 98 also increases. Thus, during reclining, while distance D increases somewhat, the increase in dimension D1 reduces the increase in dimension D as lumbar region 126 of back shell 112 is displaced forward relative to back frame 98 .

Referring again to FIG. 26 , when the user is seated in the upright position, the spine 360 of the seated user 362 tends to bend forward by a first amount at the lumbar region 364 . As the user leans back from the position of FIG. 26 to the position of FIG. 28, the curvature of the lumbar region 364 tends to increase and the user's spine 360 will also rotate a little around the hip joint 366 relative to the user's femur 368. The increase in dimension D and the curvature of the lumbar region 126 of the back shell 112 simultaneously ensures that the user's hip joints 366 and femurs 368 do not slide on the seat 16, and that the lumbar region 364 accommodates the user's spine 360. radian.

As discussed above, FIG. 27 shows the back assembly 18 of the chair assembly 10 in an upright position with the lumbar region 126 of the back shell 112 adjusted to a straight position. If the back assembly 18 is tilted from the position of FIG. 27 to the position of FIG. 29, both the back control link 342 and the cam link 350 rotate in a clockwise direction. However, the cam linkage 350 rotates at a slightly higher rate, the angle So from 31.4° to 35.9°. The distance D changes from 202 mm to 265 mm, while the angle From 24.2° to 24.1°.

With further reference to Figure 29A, if the backrest assembly 18 is reclined and the lumbar adjustment is set to high, then the angle That is 93.6°, and the distance D is 202 mm.

Accordingly, when the seat back is reclined rearwardly, the back shell 112 bends. However, if the curvature is initially adjusted to a higher level, the increased curvature of the lumbar region 126 from the upright to the reclined position is significantly greater. This is an arrangement that takes into account the fact that if the user's back is initially in a relatively flat state when sitting upright, the curvature of the user's back will not increase as much when the user leans back. To reiterate: If the user's back is relatively straight in the upright position, the user's back will remain relatively straight even when reclined, although the arc increases slightly from the upright position to the reclined position. Conversely, if a user's back is significantly curved in an upright position, the increase in curvature of the lumbar region when the user leans back will be higher than for a user whose back is initially relatively straight.

A pair of spring assemblies 442 ( FIGS. 20 and 21 ) bias the backrest assembly 18 from the reclined position F toward the upright position E. As shown in FIG. As best shown in FIG. 22 , each spring assembly 442 includes a cylindrical housing 444 having a first end 446 and a second end 448 . Each spring assembly 442 also includes a compression coil spring 450 , a first coupling 452 and a second coupling 454 . In the illustrated example, the first coupling member is secured to the first end 446 of the housing 444 , while the second coupling member 454 is secured to a rod member 456 extending through the coil spring 450 . A washer 457 is secured to the distal end of the rod member 458 and abuts one end of the coil spring 450 , while the other end of the coil spring 450 abuts the second end 448 of the housing 444 . The first coupling member 452 is pivotally secured to the back support structure 302 by a pivot pin 460 received in a pivot aperture 462 of the back support structure 302 for pivotal movement about a pivot point 461 Inside, the second coupling member 454 is pivotably coupled to the moment arm displacement assembly 466 ( FIGS. 30-32 ) via the shaft 464 to pivot about the pivot point 465 . The moment arm displacement assembly is adapted to move the bias or spring assembly 442 from a low tension setting (FIG. 33A) to a high tension setting (FIG. 34A), in which the bias assembly 442 is applied to the backrest assembly 18. Force is increased relative to low tension settings.

30A-32, the moment arm displacement assembly 466 includes: the adjustment assembly 468; the moment arm displacement linkage assembly 470, which operably couples the control input assembly 260 to the adjustment assembly 468 and allows the operator to adjust the bias Component 442 moves between low and high tension setting; The magnitude of the input force applied to the control input assembly 260 .

The adjustment assembly 468 includes a pivot pin 467 that includes a threaded aperture that receives a threaded adjustment shaft 476 therein. Adjustment shaft 476 includes a first end 478 and a second end 484, wherein first end 478 extends through aperture 480 of base structure 262 and is guided by bearing assembly 482 to pivot about a longitudinal axis. Pivot pin 467 is supported by base structure 262 via a linkage assembly 469 comprising a pair of linkage arms 471 each having a first end 473 pivotable by pivot pin 464 and the second end 475, which is pivotally coupled to the base structure by a pivot pin 477 that is pivotally received in a pivot aperture 479 of the base structure 262 262 to pivot about pivot point 481 ; and an aperture 483 that receives a corresponding end of pivot pin 467 . Pivot pin 467 is pivotally coupled to link arm 471 along its length.

The moment arm shift linkage assembly 470 ( FIGS. 30A and 30B ) includes a first drive shaft 486 extending between the control input assembly 260 and a first helical gear assembly 488 , and between the first helical gear assembly 488 and the second helical gear assembly 488 . A second drive shaft 490 extends between and operably couples a gear assembly 492 , wherein the second helical gear assembly 492 is connected to the adjustment shaft 476 . The first drive shaft 486 includes a first end 496 that is operatively coupled to the control input assembly 260 by a first universal joint assembly 498 , while a second end 500 of the first drive shaft 486 is connected to the control input assembly 260 by a second universal joint assembly 502 Operably coupled to the first helical gear assembly 488 . In the illustrated example, the first end 496 of the first drive shaft 486 includes a female coupling portion 504 of the first gimbal assembly 498, and the second end 500 of the first drive shaft 486 includes the second gimbal A female coupling portion 506 of the assembly 502 . The first helical gear assembly 488 includes a housing assembly 508 that receives a first helical gear 510 and a second helical gear 512 therein. As shown, the first helical gear 510 includes a male coupling portion 514 integral with the second gimbal assembly 502 . First end 496 of second drive shaft 490 is coupled to first helical gear assembly 488 through third universal joint assembly 516 . The first end 518 of the second drive shaft 490 includes a female coupling portion 520 of the third gimbal assembly 516 . The second helical gear 512 includes a male coupling portion 522 with which the third gimbal assembly 516 is integral. The second end 524 of the second drive shaft 490 includes a plurality of longitudinally extending splines 526 that mate with corresponding longitudinally extending splines (not shown) of a coupler member 528 . Coupler member 528 couples second end 524 of second drive shaft 490 with second helical gear assembly 492 via fourth universal joint assembly 530 . Fourth gimbal assembly 530 includes a housing assembly 532 that houses: a first helical gear 534 coupled to coupler member 528 through fourth gimbal assembly 530 , and a helical gear fixed to second end 484 of adjustment shaft 476 . The second helical gear 536 . Coupler member 428 includes a female coupling portion that receives a male coupling portion 540 integral with first helical gear 534 .

When assembled, the adjustment assembly 468 of the moment arm shift assembly 466 is operably supported by the base structure 262 and the control input assembly 260 is operably supported by the control input assembly mounting portion 296 of the seat support structure 282 . As a result, as the seat support structure 282 is moved between the fully upright position G and the fully reclined position H, the relative angle and distance between the control input assembly 260 and the adjustment assembly 468 of the moment arm displacement assembly 466 changes. The third and fourth gimbal assemblies 516, 530 cooperate with the spline assembly between the splines to compensate for these relative changes in angles and distances.

As shown most clearly in FIGS. 33A-34B, the moment arm displacement assembly 466 functions to adjust the biasing assembly 442 between low tension and high tension settings. Specifically, FIG. 33A shows the biasing assembly 442 at a low tension setting with the chair assembly 10 in an upright position, FIG. 33B shows the biasing assembly at a low tension setting with the chair assembly 10 in a reclined position, and FIG. 34A The biasing assembly 442 is shown at the high tension setting with the chair assembly in the upright position, while FIG. 34B shows the biasing assembly at the high tension setting with the chair assembly 10 in the reclined position. Take the distance 542 measured between the pivot point 465 and the second end 448 of the housing 444 of the spring assembly 442 as the distance 542 applied to the spring assembly when the moment arm displacement assembly 466 is placed in the low tension setting and the chair is in the upright position. 442 for the amount of compression referenced. Distance 542' (FIG. 33B) shows in comparison the incremental compressive force applied to spring assembly 442 when moment arm displacement assembly 466 is in the high tension setting and the chair is in the upright position. The user adjusts the amount of force exerted by the biasing assembly 442 on the back support structure 302 by moving the moment arm displacement assembly 466 from a low tension setting to a high tension setting. Specifically, the operator drives the adjustment shaft 476 of the adjustment assembly 468 through the moment arm displacement linkage assembly 470 to rotate with the input to the control input assembly 260, thereby causing the pivot shaft 467 to travel along the length of the adjustment shaft 476, thereby The compressive force exerted on spring assembly 442 is varied during pivot shaft 467 is articulated relative to base structure 262 . The pivot shaft 467 travels within a slot 544 disposed within a side plate member 546 attached to a side wall 268 of the base structure 262 . Note here that the distance 542' is greater when the moment arm displacement member 466 is at the high tension setting and the chair assembly 10 is in the upright position than when the moment arm displacement member 466 is at the low tension setting and the chair is in the upright position 542, thus showing that when the moment arm displacement member is at a high tension setting, the compressive force exerted on the spring assembly 442 is greater than at a low tension setting. Similarly, distance 543 (FIG. 33B) is greater than distance 543' (FIG. 34B), causing the biasing force exerted by biasing assembly 442 to increase and force backrest assembly 18 from the reclined position to the upright position. Note here that a change in the biasing force applied by the biasing assembly 442 corresponds to a change in the biasing torque applied about the second pivot point 276, and in some configurations, the length or biasing of the biasing assembly 442 is not changed. Pressure can also change bias torque.

35 is a graph of the amount of torque applied about the second pivot point 276 that forces the back support structure 302 from the reclined position to the upright position as the back support structure 302 is moved between the reclined position and the upright position. In the illustrated example, when the back support structure is in the upright position and the moment arm displacement member 466 is in the low tension setting, the biasing assembly 442 applies a torque of about 652 inch-pounds about the second pivot point 276, and When the back support structure is in the reclined position and the moment arm displacement member 466 is in the low tension setting it is about 933 inch-pounds, resulting in a change of about 43%. Similarly, when the back support structure is in the upright position and the moment arm displacement member 466 is in the high tension setting, the biasing assembly 442 applies a torque of about 1.47E+03 inch-pounds about the second pivot point 274, while when With the back support structure in the reclined position and the moment arm displacement 466 in the high tension setting it is about 2.58E+03 in-lbs, resulting in a variation of about 75%. As the back support structure 302 is moved between the upright and reclined positions, the amount of torque applied by the biasing assembly 442 produces a considerable This allows the overall chair assembly 10 to provide proper forward back support for users of different heights and weights.

Adjustment assist assembly 472 assists the operator in moving moment arm displacement assembly 466 from a high tension setting to a low tension setting. Adjustment assist assembly 472 includes: coil spring 548 secured to front wall 264 of base structure 262 with mounting structure 550; and snap member 552 extending around shaft 306 secured to link arm 471 and comprising a Snap portion 556 that defines aperture 558 that captures free end 560 of coil spring 548 . The coil spring 548 exerts a force F on the buckle part 552, the shaft rod 306 and the link arm 471 in an upward vertical direction, thereby reducing the time when the user wants to move the moment arm displacement assembly 466 from a low tension setting to a high tension setting. The input force that must be exerted on the control input assembly 260 .

As noted above, the seat assembly 16 is longitudinally movable relative to the control assembly 14 between a retracted position C and a deployed position D (FIG. 3). As shown most clearly in FIGS. 19 , 36 and 37 , direct drive assembly 562 includes drive assembly 564 and linkage assembly 566 that couples control input assembly 260 to drive assembly 564 , thereby allowing the user to adjust seat assembly 16 The linear position of the seat assembly is adjusted relative to the linear position of the control assembly 14 . In the illustrated example, the seat support plate 32 includes a C-shaped guide rail 38 that wraps around and slidably engages a corresponding guide flange 570 of a control plate 572 of the control assembly 14 . A pair of C-shaped, longitudinally extending connecting rails 574 are positioned within respective rails 38 and coupled to seat support plate 32 . A pair of C-shaped bushing members 576 extend longitudinally within the connecting rail 574 and are positioned between the connecting rail 574 and the guide flange 570 . The drive assembly 564 includes a rack member 578 having a plurality of downwardly extending teeth 580 . Drive assembly 564 also includes a rack guide 582 having a C-shaped cross-sectional configuration that defines a channel 584 that slidably receives rack member 578 therein. Rack guide 582 includes a slot 586 along its length that cooperatively receives bearing member 588 therein. Alternatively, the bearing member 588 may be formed as an integral part with the rack guide 582 . Drive assembly 564 also includes a drive shaft 590 having a first end universally coupled with control input assembly 260 and a second end 594 having a plurality of teeth 596 radially spaced from one another. In assembly, the seat support plate 32 is slidably coupled with the control plate 572 as described above, with the rack member 578 secured to the underside of the seat support plate 32 and the rack guide 582 secured to the control plate 572 in an upwardly opening channel 598 . In operation, an input force applied by a user to control input assembly 260 is transmitted through linkage assembly 566 to drive assembly 564, thereby driving teeth 596 of drive shaft 590 against teeth 580 of rack member 578 and causing the rack Member 578 and seat support plate 32 slide relative to rack guide 582 and control plate 572 .

With further reference to FIGS. 38-40 , the chair assembly 10 includes a height adjustment assembly 600 that allows vertical adjustment of the seat 16 and backrest 18 relative to the base assembly 12 . The height adjustment assembly 600 includes a pneumatic cylinder 28 arranged vertically in the central column 26 of the base assembly 12 in a known manner.

A bracket structure 602 is secured to the housing or base structure 262 and the upper end portion 604 of the pneumatic cylinder 28 is received in an opening 606 of the base structure 262 in a known manner. The pneumatic cylinder 28 includes an adjustment valve 608 that can be moved down to release the pneumatic cylinder 28 to provide height adjustment. The bell crank 610 has an upwardly extending arm 630 and a horizontally extending arm 640 configured to engage the release valve 608 of the pneumatic cylinder 28 . A bell crank 610 is rotatably mounted to bracket 602 . A cable assembly 612 operably interconnects the bell crank 610 with the adjustment wheel/lever 620 . Cable assembly 612 includes an inner cable 614 and an outer cable or sheath 616 . Outer sheath 616 includes a ball fitting 618 that is rotatably received in a ball socket 622 formed in bracket 602 . The second ball fitting 624 is connected to an end 626 of the inner cable 614 . The second ball fitting 624 is rotatably received in the second ball socket 628 of the upwardly extending arm 630 of the bell crank 610 to allow rotational movement of the cable end during height adjustment.

A second or outer end portion 632 of the inner cable 614 wraps around the wheel 620 and an end fitting 634 is connected to the inner cable 614 . The tension spring 636 is connected to the end fitting 634 and the seat structure at 638. The spring 636 creates tension in one direction on the inner cable 614, and when the valve 608 is released, the cable 614 is also displaced in the same direction to turn the bell crank 610. Spring 636 does not produce enough force to actuate valve 608 , but spring 636 produces enough force to bias arm 640 of bell crank 610 into contact with valve 608 . In this way, false play or looseness due to component tolerances is eliminated. During operation, the user manually turns the adjustment wheel 620 to create tension on the inner cable 614 . This causes the bell crank 610 to rotate causing the arm 640 of the bell crank 610 to press against and actuate the valve 608 of the pneumatic cylinder 28 . An internal spring (not shown) of pneumatic cylinder 28 biases valve 608 upward, moving valve 608 to a non-actuated position after adjustment wheel 620 is released.

The control input assembly 260 (FIGS. 19 and 41-43) includes a first control input assembly 700 and a second control input assembly 702, each adapted to communicate input from a user to the chair member and chair member to which they are coupled. Functions, chair components and functions are housed within housing assembly 704 . Control input assembly 260 includes anti-backdrive assembly 706 , overload clutch assembly 708 , and knob 710 . Anti-backdrive mechanism or assembly 706 that prevents direct drive assembly 562 ( FIGS. 36 and 37 ) and seat assembly 16 from being driven between retracted and deployed positions C, D without input from control assembly 700 . The anti-backdrive assembly 706 is received within the interior 712 of the housing assembly 704 and includes an adapter 714 including at one end a male portion 716 of a gimbal adapter coupled to the second end 594 of the drive shaft 590 ( FIG. 37 ), And includes a splined connector 717 at the other end. Cam member 718 is coupled to adapter 714 by clutch member 720 . Specifically, cam member 718 includes a splined end 722 that is coupled for rotation with knob 710 and a cam end 724 that has an outer cam surface 726 . Clutch member 720 includes a pair of inwardly disposed splines 723 that slidably engage spline connector 717 having a cam surface 730 that cams with an outer cam surface 726 of cam member 718 as described below. join. Clutch member 720 has a conical clutch surface 719 received in engagement therewith by a locking ring 732 which is locked for rotation relative to housing assembly 704 and includes a conical clutch surface 721 corresponding to clutch surface 719 of clutch member 720, They cooperate to form a cone clutch. Coil spring 734 biases clutch member 720 into engagement with locking ring 732 .

When there is no input, the biasing spring 734 forces the conical surface of the clutch member 720 into engagement with the conical surface of the locking ring 732, thereby preventing "back drive"—that is, only in the absence of input from the first control input assembly 700. Seat assembly 16 is adjusted between retracted and deployed positions C, D by applying a rearward or forward force to seat assembly 16 . In operation, the operator actuates the direct drive assembly 562 via the first control input assembly 700 to move the seat assembly 16 between the retracted and deployed positions C,D. Specifically, the rotational force applied by the user to the knob 710 is transmitted from the knob 710 to the cam member 718 . As the cam member 718 rotates, the outer cam surface 726 of the cam member 718 acts on the cam surface 730 of the clutch member 720, thereby overcoming the biasing force of the spring 734 and forcing the clutch member 720 out of the engaged position, wherein the clutch member 720 disengages the locking ring 732. Rotational force is then transmitted from cam member 718 to clutch member 720 to adapter 714 , which is coupled to direct drive assembly 762 via linkage assembly 566 .

Note here that the small amount of tolerance in the first control input assembly 700 allows the cam member 718 to move (or "wobble") slightly in both the linear and rotational directions as the clutch member 720 is moved between the engaged and disengaged positions. A rotating annular damper element 736 comprising thermoplastic elastomer (TPE) is located within interior 712 of housing 704 and is attached to clutch member 720 . In the illustrated example, the damper element 736 is pressed against and frictionally engages the inner wall of the housing assembly 704 .

The first control input assembly 700 also includes a second knob 738 adapted to allow a user to adjust the vertical position of the chair assembly between a lowered position A and a raised position B as described below.

The second control input assembly 702 is adapted to adjust the tension applied to the backrest assembly 18 during recline and to control the recline of the backrest assembly 18 . The first knob 740 is operatively coupled to the moment arm displacement assembly 466 by the moment arm displacement linkage assembly 470 . Specifically, the second control input assembly 702 includes a male gimbal portion 742 that couples with the female gimbal portion 504 ( FIGS. 30 and 31 ) of the shaft 486 of the moment arm displacement linkage assembly 470 .

The second knob 760 is adapted to adjust the recline of the backrest assembly 18 via a cable assembly 762 that operably couples the second knob 760 to a variable backrest stop assembly 764 ( FIG. 43 ). The cable assembly 762 includes a first cable structure 766, a second cable structure 768, and a cable tube 770 extending therebetween that slidably receives an actuation cable 772 therein. Cable 772 includes a distal end 774 that is fixed relative to base structure 262 and biased in a direction 776 by a coil spring 778 . The variable backrest assembly 764 includes: a stop 780 having a plurality of vertically graded steps 782; a support bracket 784 fixedly supported relative to the seat assembly 16; and a slide member 786 slidably coupled to the support The bracket 784 is slidable in a front-to-rear direction 788 and is fixedly coupled to the stop member 780 by a pair of screws 790 . The cable 772 is clamped between the stop member 780 and the slide member 786 such that longitudinal movement of the cable 772 causes the stop member 780 to move in a fore-aft direction 788 . In operation, the user adjusts the position of the stop member 780 via an input to the second knob 760 to adjust the possible back recline. As the back assembly 18 moves from the upright to the reclined position, selected ones of the plurality of steps 782 of the stop member 780 contact the rear edge 792 of the base structure 262 to limit the available back recline.

Each arm assembly 20 ( FIGS. 44-46 ) includes an arm support assembly 800 that is pivotally supported from an arm base structure 802 and that adjustably supports an armrest assembly 804 . Arm support assembly 800 includes a first arm member 806, a second arm 808, an arm support structure 810, and an armrest assembly support member 812 that cooperate to form a 4-bar linkage assembly. In the illustrated example, the first arm member 806 has a U-shaped cross-sectional configuration and includes: a first end 814 pivotally coupled to the arm support structure 810 to pivot about a pivot point 816; and a second End 818 , which is pivotally coupled to armrest assembly support member 812 for pivotal movement about pivot point 820 . The second arm member 808 has a U-shaped cross-sectional configuration and includes a first end 822 that is pivotally coupled to the arm support structure 810 to pivot about a pivot point 824; and a second end 826 that is pivotable Ground coupled to armrest assembly support member 812 to pivot about pivot point 828. As shown, the 4-bar linkage assembly of the arm support assembly 800 allows the armrest assembly 804 to be adjusted between a fully raised position K and a fully lowered position L, wherein The distance between them is preferably at least about 4 inches. Each arm assembly also includes a first arm cover member 807 having a U-shaped cross-sectional configuration and including a first edge portion 809, and a second arm cover member 811 having a U-shaped cross-sectional configuration and including a second edge portion 813, wherein The first arm part 806 is received within the first arm cover part 807 and the second arm part 808 is received within the second arm cover part 811 such that the second edge portion 813 and the first edge portion 809 overlap.

Each arm base structure 802 includes a first end 830 connected to the control assembly 14 , and a second end 832 pivotally supporting the arm support structure 810 for rotation of the arm assembly 20 about a vertical axis 835 in a direction 837 . The first end 830 of the arm base structure 802 includes a main body portion 833 and a narrowed bayonet portion 834 extending outwardly therefrom. In assembly, the main body portion 833 and the bayonet portion 834 of the first end 830 of the arm base structure 802 are received between the control board 572 and the seat support structure 282 and secured by a plurality of mechanical fasteners (not shown). Fastened thereto, mechanical fasteners extend through the body portion 833 and the bayonet portion 834 of the arm base structure 802 , the control board 572 and the seat support structure 282 . The second end 832 of the arm base structure 802 pivotally receives the arm support structure 810 therein.

As best shown in FIG. 47 , the arm base structure 802 includes an upwardly opening support recess 836 having a cylindrical upper portion 838 and a conical lower portion 840 . Bushing member 842 is positioned within bearing recess 836 and is similarly configured as lower portion 840 of bearing recess 836 , including conical portion 846 . Arm support structure 810 includes a lower end having a cylindrical upper portion 848 and a conical lower portion 850 received within lower portion 846 of bushing member 842 . The upper end 852 of the arm support structure 810 is configured to operably engage in a vertical locking arrangement, as described below. The pin member 854 is positioned within a centrally located, axially extending bore 856 of the arm support structure 810 . In the illustrated example, the pin member 854 is made of steel, while the upper end 852 of the arm support structure 810 is made of metal powder formed around the proximal end of the pin member 854, and wherein the combination of the upper end 852 and the pin member 854 is Encased in an outer aluminum coating. The distal end 853 of the pin member 854 includes an axially extending threaded bore 855 which threadably receives an adjustment screw 857 therein. The arm base structure 802 includes a cylindrical second recess 858 separated from the support recess 836 by a wall 860 . Coil spring 864 is positioned within second recess 858 about distal end 853 of pin member 854 and is trapped between wall 860 of arm base structure 802 and washer member 866 such that coil spring 864 exerts force in the direction of arrow 868. A downward force is applied to pin member 854 , thereby bringing the lower end of arm support structure 810 into tight frictional engagement with bushing member 842 , and bushing member 842 into tight frictional engagement with support recess 836 of arm base structure 802 . Adjustment screw 857 is adjustable to adjust the frictional interaction between arm support structure 810, bushing member 842, and arm base structure 802 and to increase the user's ability to pivot arm assembly 20 about pivot access point 835 in pivot direction 837. The force required to move. The pivotal connection between the arm support structure 810 and the arm base structure 802 allows the entire arm assembly 800 to move in the direction of 876 from a line 874 extending through the pivot access point 835 and parallel to the central axis 872 of the seat assembly 16 (Fig. 48) Pivot inwardly and outwardly in direction 878 from line 874 . Preferably, arm assembly 20 pivots from line 874 in direction 876 for greater than or equal to about 17° and from line 874 in direction 878 for greater than or equal to about 22°.

With further reference to FIGS. 49-51 , the vertical height adjustment of the armrest is accomplished by turning the 4-linkage formed by the first arm member 806 , the second arm member 808 , the arm support structure 810 and the armrest assembly support member 812 . Gear member 882 includes a plurality of teeth 884 arranged in an arc about pivot point 816 . Locking member 886 is pivotally mounted to arm 806 at pivot point 888 and includes a plurality of teeth 890 that selectively engage teeth 884 of gear member 882 . When teeth 884 and 890 are engaged, the height of armrest 804 is fixed due to the rigid triangle formed between pivot points 816 , 824 and 888 . If a downward force F4 is applied to the armrest, a counterclockwise (FIG. 50) moment is generated on the locking member 886. This moment pushes the teeth 890 into engagement with the teeth 884, thereby securely locking the height of the armrest.

An elongated lock member 892 is rotatably mounted to arm 806 at pivot 894 . A low friction polymer bearing member 896 is disposed on the upper curved portion 893 of the elongated lock member 892 . As discussed in more detail below, a manual release lever or member 898 includes a pad 900 that can be moved upwardly by the user to selectively release the teeth 890 of the locking member 886 from the teeth 884 of the gear member 882 to allow the armrest to move upward. Vertical height adjustment.

A leaf spring 902 includes a first end 904 that engages a notch 906 formed in an upper edge 908 of the elongated lock member 892 . Therefore, the leaf spring 902 is formed as a cantilever having the notch 906 of the lock member 892 as a support point. The upwardly extending tab 912 of the elongated lock member 892 is received in the elongated slot 910 of the leaf spring 902 to position the leaf spring 902 relative to the lock member 892 . End 916 of leaf spring 902 presses upward ( F1 ) against knob 918 of locking member 886 , thereby creating a moment that tends to rotate locking member 886 about pivot 888 in a clockwise (release) direction ( FIG. 51 ). The leaf spring 902 also generates a clockwise moment on the elongated lock member 892 at the notch 906, and also generates a moment on the locking member 886 that tends to pull the locking member 886 in a clockwise (release) direction about the pivot 888 turn. This moment tends to disengage tooth 890 from tooth 884 . If the teeth 890 disengage from the teeth 884, the height of the armrest assembly can be adjusted.

Locking member 886 includes a recess or notch 920 ( FIG. 50 ) that receives a tip 922 of elongated locking member 892 . Recess 920 includes a first shallow V-shaped portion having corner 924 . The recess also includes a small recess or notch 926 and a lateral, upwardly facing surface 928 abutting notch 926 .

As mentioned above, the leaf spring 902 generates a moment on the locking member 886 that tends to disengage the tooth 890 from the tooth 884 . However, when the tip or end 922 of the elongated lock member 892 engages the notch 926 of the recess 920 of the lock member 886, this engagement prevents rotational movement of the lock member 886 in a clockwise (release) direction, thereby connecting the teeth 890 and 884 lock into engagement with each other and prevent height adjustment of the armrest.

To release the arm assembly for height adjustment of the armrest, the user pulls the pad 900 upward against a small leaf spring 899 (FIG. 50). The release member 898 rotates about an axis 897 extending in a front-to-rear direction, while the inner end of the manual release lever 898 pushes down against the upper curved portion 893 ( FIG. 51 ) of the bearing member 896 /elongated lock member 892 . This creates a downward force which rotates the elongated lock member 892 about the pivot 894. This moves the end 922 ( FIG. 50 ) of the elongated lock member 892 upward so that it is adjacent to the shallow corner 924 of the recess 920 of the lock member 886 . This displacement of the lock member 892 releases the lock member 886 such that the lock member 886 rotates in a clockwise (release) direction due to the bias of the leaf spring 902 . This rotation disengages teeth 890 from teeth 884 to allow height adjustment of the armrest assembly.

The armrest assembly is also configured to prevent disengagement of the height adjustment member during a downward force F4 ( FIG. 50 ) is applied to the armrest pad 804 . Specifically, the downward force F4 will tend to move pivot point 820 toward pivot point 824 due to the 4-linkage formed by arm members (806, 808), arm support structure 810, and armrest assembly support member 812. However, an elongated lock member 892 is disposed generally between pivots 820 and 824 in line with them, thereby preventing downward rotation of the 4-bar linkage. As noted above, the downward force F4 causes the teeth 890 to tightly engage the teeth 884, securely locking the height of the armrest. If the release lever 898 is actuated when a downward force F4 is applied to the armrest, the lock member 892 will move and the end 922 of the elongated lock member 892 will disengage from the notch 926 of the recess 920 of the lock member 886 . However, the torque applied to the locking member 886 keeps the teeth 890 and 884 engaged even though the locking member 892 is moved to the released position. Thus, the configuration of the 4-bar linkage, locking member 886 and gear member 882 provides a mechanism wherein height adjustment of the armrest cannot be made if a downward force F4 is acting on the armrest.

As shown most clearly in FIGS. 52 and 53 , each armrest assembly 804 is adjustably supported by an associated arm support assembly 800 such that the armrest assembly 804 can be in an inline position M and a pivoted position about a pivot point 960 N pivots inwardly and outwardly. Each armrest assembly is also linearly adjustable between a retracted position O and a deployed position P relative to its associated arm support assembly 800 . Each armrest assembly 804 ( FIG. 53 ) includes an armrest housing assembly 962 integral with the armrest assembly support member 812 and defining an interior volume 964 . The armrest assembly 804 also includes a support plate 966 having a planar body portion 968 with a pair of mechanical fastener receiving apertures 969 and an upwardly extending pivot boss 970 . The rectangular slider housing 972 includes a planar portion 974 through which an elliptical aperture 976 extends, a pair of sidewalls 978 extending perpendicularly from the planar portion 974 longitudinally, and a pair of sidewalls 978 extending orthogonally from the planar portion 974. An end wall 981 extending transversely across its end. The armrest assembly 804 also includes a rotational and linear adjustment member 980 having a planar body portion that defines an upper surface 984 and a lower surface 986 . A centrally located aperture 988 extends through body portion 982 and pivotally receives pivot boss 970 therein. The rotary and linear adjustment member 980 also includes: a pair of arcuate apertures 990 at opposite ends thereof; A plurality of spines 993 are defined therebetween. Rotary selection member 994 includes a planar body portion 996 and a pair of flexible resilient fingers 998 centrally located therein, each including a downwardly extending engagement portion 1000 . Each armrest assembly 804 also includes an arm pad base 1002 and an arm pad component 1004 molded over the base 1002 .

In assembly, the support plate 966 is positioned on the armrest housing assembly 962 with the slider housing 972 on the support plate 966 such that the bottom surface 1006 of the planar portion 974 frictionally abuts the top surface 1008 of the support plate 966, rotating and linear adjustment member 980 between side wall 978 and end wall 980 of slider housing 972 such that bottom surface 986 of the rotational and linear adjustment member frictionally engages planar portion 974 of slider housing 972, and between the rotational and linear adjustment members Rotary selection component 994 above component 980 . A pair of mechanical fasteners, such as rivets 1010, extend through the aperture 999 of the rotary selection member 994, the arcuate aperture 990 of the rotary and linear adjustment member 980, and the aperture 969 of the support plate 966 and are threadedly secured to the armrest housing Assembly 962 , thereby securing the linear movement of support plate 966 , rotary and linear adjustment member 980 , and rotary selection member 994 relative to armrest housing 962 . Then, the base 1002 and the arm pad member 1004 are fixed to the slider housing 972 . The above arrangement allows the slider housing 972, the base 1002 and the arm pad member 1004 to slide in a linear direction so that the armrest assembly 804 can be adjusted between the extended position O and the extended position P. Rivet 1010 is adjustable to adjust the clamping force exerted on slider housing 972 by support plate 966 and rotational and linear adjustment member 980 . The base 1002 includes a centrally located, upwardly extending raised portion 1020, and a corresponding downwardly disposed concave portion (not shown) having a pair of longitudinally extending sidewalls. Each side wall includes a plurality of ribs and spines, similar to ribs 991 and spines 993 previously described. In operation, when the arm pad 1004 is moved in a linear direction, the pivot bosses 970 engage the detents of the recesses, thereby providing tactile feedback to the user. In the illustrated example, the pivot boss 970 includes a slot 1022 that allows the end of the pivot boss 970 to elastically deform when the pivot boss 970 engages the detent, thereby reducing wear on the detent. The arcuate aperture 990 of the rotational and linear adjustment member 980 allows the adjustment member 980 to pivot about the pivot boss 970 of the support plate 966 and allows the armrest assembly 804 to be adjusted between the inline position M and the angled position N. In operation, the engaging portion 1000 of each finger 998 of the rotating selection member selectively engages the detents 992 defined between the ribs 991, thereby allowing the user to position the armrest assembly 804 in a selected rotational position, and provides tactile feedback to the user as the armrest assembly 804 is rotationally adjusted.

An embodiment of a chair assembly is shown in various views, including a perspective view (FIG. 55), a front view (FIG. 56), a first side view (FIG. 57), a second side view (FIG. 58), a rear view ( Fig. 59), top plan view (Fig. 60) and bottom plan view (Fig. 61). An embodiment of an arm assembly is shown in various views, including a perspective view (FIG. 62), a front view (FIG. 63), a first side view (FIG. 64), a second side view (FIG. 65), a rear view ( Figure 66), top plan view (Figure 67) and bottom plan view (Figure 68).

In the foregoing description, those skilled in the art can readily understand that various alternative implementations and various modifications to the components and elements of the present invention and the present invention can be made without departing from the disclosed concept. Such modifications are to be regarded as included in the appended claims unless those claims by their text expressly state otherwise.

Claims (104)

1. A chair assembly comprising: A four-bar linkage assembly comprising: a first linkage member having a first end and a second end; a second linkage member having a first end and a second end; A third link member having a first end pivotally coupled to a first end of the first link member for rotation about a first pivot point, and a first end pivotally coupled to the second link member one end with a second end pivoting about a second pivot point; and A fourth link member having a first end pivotably coupled to a second end of the first link member for rotation about a third pivot point, and a first end pivotally coupled to the second link member the two ends are a second end that rotates about a fourth pivot point; wherein the four-bar linkage assembly includes a lower end and an upper end adjustable between a raised position and a lowered position; an armrest assembly adapted to support the arms of a seated user thereon and supported on the upper end of the four-bar linkage assembly; and wherein the lower end of the four-bar linkage assembly is pivotally supported by the arm support structure to pivotally move about a fifth pivot point, so that the upper end of the four-bar linkage assembly can move between a first position and a second position, the second The second position is located laterally outside the first position. 2. The chair assembly of claim 1, wherein the first linkage member includes a U-shaped cross-sectional configuration along a length thereof. 3. The chair assembly of claim 2, wherein the second link member comprises a U-shaped cross-sectional configuration along a length thereof, and wherein the first link member and the second link member cooperate to form a U-shaped cross-sectional configuration along the first and second The length of the linkage member extends longitudinally to the internal passage. 4. A chair assembly as claimed in any preceding claim, wherein the third linkage member comprises at least part of an arm support structure. 5. A chair assembly as claimed in any preceding claim, wherein the fourth linkage member comprises at least part of an armrest assembly. 6. The chair assembly of any preceding claim, wherein the lower end of the four-bar linkage assembly includes a selected one of a pivot boss and a pivot aperture, and the arm support structure includes a pivot boss and a pivot The other one of the apertures, and wherein the pivot boss is received in the pivot aperture to pivotally support the four-bar linkage assembly to rotate around the fifth pivot point. 7. The chair assembly of claim 6, wherein the pivot boss is conical, and wherein the pivot aperture is conical and cooperatively receives the pivot boss therein. 8. The chair assembly of any one of claims 6 and 7, wherein the arm support structure includes the pivot aperture. 9. The chair assembly of any one of claims 6-8, wherein friction is applied between the pivot boss and the pivot aperture to maintain the four-bar linkage assembly between the first position and the second position. A selected position between the two positions, and wherein the four-bar linkage assembly is not held in the selected position by any other mechanical means other than the frictional force. 10. The chair assembly of any one of claims 6-9, wherein the pivot boss and the pivot aperture are spring biased toward each other. 11. The chair assembly of claim 10, wherein friction between the pivot boss and the pivot aperture is adjustable by mechanical means. 12. The chair assembly of any preceding claim, further comprising: a locking assembly actuatable between a locked position in which the four-bar linkage is locked in a selected vertical position and an unlocked position in which the four-bar linkage can be raised and lowered are adjusted between the positions. 13. The chair assembly of claim 12, wherein the third linkage member includes at least a portion of a locking assembly. 14. A chair assembly as claimed in any preceding claim, wherein the armrest assembly is pivotally adjustable relative to the upper portion of the four-bar linkage assembly. 15. The chair assembly of claim 14, wherein the armrest assembly is longitudinally adjustable relative to the upper portion of the four-bar linkage assembly. 16. The chair assembly of any preceding claim, wherein the four-bar linkage assembly adjusts between a raised position and a lowered position by greater than or equal to about 35°. 17. The chair assembly of any preceding claim, wherein the upper end of the four-bar linkage assembly moves greater than or equal to about 38° between the first position and the second position. 18. The chair assembly of any preceding claim, further comprising: a seat support structure comprising a seat support surface configured to support a seated user thereon, wherein the seat support surface includes a longitudinal axis; Wherein the upper end of the four-bar linkage assembly is displaced greater than or equal to about 22° outward from an axis parallel to the longitudinal axis of the seat support surface. 19. The chair assembly of any preceding claim, wherein the upper end of the four-bar linkage assembly is displaced inwardly by more than or equal to about 17° from an axis parallel to the longitudinal axis of the seat support surface. 20. The chair assembly of any preceding claim, wherein the armrest assembly is pivotally adjustable relative to the four-bar linkage assembly. 21. The chair assembly of claim 20, wherein the armrest assembly is linearly adjustable relative to the four-bar linkage assembly. 22. The chair assembly of any preceding claim, wherein the armrest assembly is linearly adjustable relative to the four-bar linkage assembly. 23. A chair assembly comprising: A four-bar linkage assembly comprising: a first link member having a first end, a second end, and a U-shaped cross-sectional configuration disposed along a length thereof; The second link member has a first end, a second end, and a U-shaped cross-sectional configuration along a length thereof, and wherein the first link member and the second link member cooperate to form a the length of the link member extends longitudinally to the interior space; a third link member having a first end and a second end, the first end being pivotally coupled to the first end of the first link member to rotate about a first pivot point, and the second end being pivotable ground coupled to the first end of the second linkage member for rotation about the second pivot point; and a fourth link member having a first end and a second end, the first end being pivotally coupled to the second end of the first link member to rotate about a third pivot point, the second end being pivotable ground coupled to the second end of the second linkage member for rotation about a fourth pivot point; wherein the four-bar linkage assembly includes a lower end and an upper end vertically adjustable between a raised position and a lowered position; an armrest assembly adapted to support the arms of a seated user thereon and supported on the upper end of the four-bar linkage assembly; and a locking assembly including a first locking link having a first surface, and a second locking link having a plurality of teeth corresponding to a plurality of vertical positions of the four-bar linkage between a raised position and a lowered position position, wherein the first and second locking links are movable relative to each other between a locked position and an unlocked position, in the locked position, the first surface engages at least one of the plurality of teeth to prevent the four-bar linkage from lifting adjusted between raised and lowered positions, and in the unlocked position, the first surface and the plurality of teeth are spaced apart from each other, thereby allowing the four-bar linkage to be adjusted between raised and lowered positions, and Wherein both the first and the second locking couplings have at least an appreciable portion located in the inner space. 24. The chair assembly of claim 23, further comprising: a first set of parts at least partially housing the first link member and having at least one elongated first edge portion; The second set of parts at least partially accommodates the second linkage member and has at least one elongated second edge portion at least partially overlapping the first edge portion, wherein when the four-bar linkage assembly is raised During adjustment between the and lowered positions, the first edge portion and the second edge portion move relative to each other. 25. The chair assembly of claim 24, wherein the first edge portion and the second edge portion overlap each other in both the raised and lowered positions. 26. The chair assembly defined in any one of claims 23-25, wherein the third linkage member includes the plurality of teeth. 27. The chair assembly of any one of claims 23-26, wherein the first locking link is pivotally coupled to the first linkage member. 28. The chair assembly of any one of claims 23-27, wherein the locking assembly is biased toward the locked position. 29. The chair assembly of any one of claims 23-28, wherein the locking assembly is biased toward the locked position by a leaf spring. 30. The chair assembly of any one of claims 23-29, wherein the plurality of teeth form an arcuate path. 31. The chair assembly of claim 30, wherein the plurality of teeth form the arcuate path about the first pivot point. 32. The chair assembly of any one of claims 23-31, wherein a downward force applied to the armrest assembly forces the first surface into engagement with at least one of the plurality of teeth. 33. The chair assembly of any one of claims 23-32, wherein the armrest assembly is linearly adjustable relative to the four-bar linkage assembly. 34. The chair assembly of any one of claims 23-33, wherein the armrest assembly is laterally adjustable relative to the four-bar linkage assembly. 35. A chair assembly comprising: arm support structure; an armrest assembly adapted to support the arms of a seated user thereon; an arm support assembly having a lower end supported by the arm support structure and an upper end supporting the armrest assembly thereon, wherein the arm support assembly is adjustable between a vertically raised position and a vertically lowered position; and Locking component, which contains: a first locking coupling with at least one of a plurality of teeth and a first surface; A second locking coupling with a plurality of teeth and another first surface movable between a locked position and an unlocked position in which the first surface engages at least one of the plurality of teeth , to prevent the arm support assembly from being adjusted between the raised and lowered positions, and in the unlocked position, the first surface and the plurality of teeth are spaced apart from each other, thereby allowing the arm support assembly to be adjusted between the raised and lowered positions is adjusted between an actuating link operatively coupled to the first locking link and adapted to move between first and second positions, in the first position the first locking link is moved by the actuator link to the locked position, in the second In the second position, the first locking coupling is moved to the unlocking position by the actuator coupling; as well as An actuator member operatively coupled to the actuator, wherein at least a portion of the actuator member is actuatable by a seated user, thereby allowing the user to couple the actuator between the first and second positions to move between. 36. The chair assembly of claim 35, wherein the second locking link is biased toward the locked position. 37. The chair assembly of any one of claims 35 and 36, wherein the second locking link is biased toward the locked position by a leaf spring. 38. The chair assembly of any one of claims 35-37, wherein the actuator linkage comprises a leaf spring. 39. The chair assembly of any one of claims 35-38, wherein the actuator link includes an arcuate abutment surface, and wherein the actuator member abuts the abutment surface of the actuator link. 40. The chair assembly of any one of claims 35-39, wherein the actuator linkage is pivotally coupled to the arm support assembly. 41. The chair assembly of any one of claims 35-40, wherein the first locking link is pivotally coupled to the arm support assembly. 42. The chair assembly of any one of claims 35-41, wherein the arm support assembly comprises a four-bar linkage assembly comprising: a first linkage member with a first end and a second end; a second linkage member with a first end and a second end; The third link member has a first end and a second end, the first end is pivotally coupled to the first end of the first link member to rotate about the first pivot point, and the second end is pivotally coupled to the first end of the first link member. coupled to the first end of the second linkage member for rotation about a second pivot point; and a fourth link member having a first end and a second end, the first end is pivotally coupled to the second end of the first link member to rotate about a third pivot point, the second end is pivotally A second end coupled to the second linkage member for rotation about a fourth pivot point. 43. The chair assembly of claim 42, wherein the third linkage member includes the plurality of teeth. 44. The chair assembly of any one of claims 35-44, wherein the plurality of teeth form an arcuate path. 45. The chair assembly of claim 44, wherein the arm support assembly is pivotally coupled to the arm support structure, and wherein the plurality of teeth form the arc about a pivot point between the arm support assembly and the arm support structure path. 46. The chair assembly of any one of claims 35-45, wherein a downward force applied to the armrest assembly forces the first surface into engagement with at least one of the plurality of teeth. 47. A chair assembly as claimed in any one of claims 35-46, wherein the actuator member is positioned adjacent to the armrest assembly such that the actuator member is easily accessible to a seated user. 48. The chair assembly of any one of claims 35-47, wherein the armrest support is pivotally adjustable relative to the arm support structure. 49. The chair assembly of any one of claims 35-48, wherein the armrest support is linearly adjustable relative to the arm support structure. 50. An armrest assembly for an office chair, the armrest assembly comprising: have external parts with cushions mounted thereon; an inner component configured to be secured to an office chair structure, the inner component having teeth disposed thereon; upper and lower members extending between and pivotally coupling the inner and outer members to form a four-bar linkage; a vertical adjustment lock assembly for locking the height of the upholstery relative to the interior components; The Vertical Adjustment Lock Kit contains: removable release parts; an actuator member displaceable between a locked position and an unlocked position when the release member moves, the actuator member defining a base end; a pivotable locking member having teeth that selectively engage teeth on an inner member of the four-bar linkage; and a spring that biases the actuator member toward the locked position and also biases the teeth of the pivotable locking member out of engagement with the teeth on the inner member of the four-bar linkage; wherein the base end of the actuator member moves into the first recess of the locking member to allow the teeth of the locking member to move out of engagement with the teeth of the inner member of the four-bar linkage; and A second lock that includes a locking second recess in the locking member that receives the end of the actuator member and prevents movement of the locking member when downward force is applied to the cushion. 51. The armrest assembly of claim 50, wherein the first recess includes a shallow V-shaped surface. 52. The armrest assembly of claim 51, wherein the first recess includes first and second substantially flat surfaces that intersect each other to define a corner of the shallow V-shaped surface, and wherein the locking A second recess is formed in the first substantially flat surface at a location spaced from the corner. 53. An armrest assembly as claimed in any one of claims 50-52, wherein the spring comprises a leaf spring. 54. The armrest assembly of claim 53, wherein the leaf spring generates a moment acting on the pivotable lock. 55. An armrest assembly as claimed in any one of claims 52 and 53, wherein the leaf spring generates a moment acting on the actuator member. 56. The armrest assembly of any one of claims 50-55, wherein the teeth on the inner part of the four-bar linkage form a convex arc. 57. An armrest assembly as claimed in any one of claims 50-56, wherein the teeth on the movable locking member form a concave arc. 58. An armrest assembly as claimed in any one of claims 50-57, wherein the base end of the actuator member is pointed. 59. The armrest assembly of any one of claims 50-58, wherein the actuator member is pivotally coupled to the upper member, and when the base end of the actuator member engages the locking second recess , the actuator part forms a rigid triangular linkage with the upper part and the inner part. 60. An armrest assembly as claimed in any one of claims 50-59, wherein the locking second recess is formed at an end of the first recess. 61. A chair assembly comprising: a base structure defining an upper portion and a lower portion underlying the upper portion; a seat support structure comprising an upwardly facing seat support surface configured to support a seated user thereon; an upwardly extending back structure with a forward facing back support surface configured to support the user's back in a generally upright position; a control linkage with a first end pivotally coupled to the rear portion of the seat support structure, and a second end pivotally coupled to the rear portion of the back support structure; An armrest assembly comprising an arm support structure coupled to the seat support structure, the armrest assembly having an upwardly facing arm support surface movable upwardly and downwardly, and a four-bar linkage movably coupled to the arm support structure and the armrest assembly assembly, wherein the four-bar linkage assembly includes: a first linkage member with first and second ends; a second linkage member with first and second ends; a third link member having a first end and a second end, the first end being pivotally coupled to the first end of the first link member to rotate about a first pivot point, and the second end being pivotable ground coupled to the first end of the second linkage member for rotation about the second pivot point; and a fourth link member having a first end and a second end, the first end is pivotally coupled to the second end of the first link member to rotate about a third pivot point, the second end is pivotally coupled to the second end of the second linkage member for rotation about a fourth pivot point; wherein the first, second, third and four pivot points each define a first, second, third and fourth corner of the four-bar linkage, and wherein the first and fourth corners define a diagonal distance therebetween , the diagonal distance decreases during the downward movement of the arm support surface; and A rigid link operably couples the first and fourth corners to place the rigid link in a compressed state to prevent the diagonal distance from decreasing, thereby locking the arm support surface at a user-selected height. 62. The armrest assembly of claim 61, wherein the arm support surface is provided on the third link member. 63. The armrest assembly of any one of claims 61 and 62, wherein the fourth linkage member comprises an inner member with a plurality of teeth disposed thereon and secured to the arm support structure, and comprising: A pivotable locking member with a plurality of teeth that selectively engage teeth on an inner member of the four-bar linkage. 64. The armrest assembly of any one of claims 61-63, wherein the rigid coupling comprises an actuator member movable between locked and unlocked positions, the actuator member defining a base end; and comprising: a spring that biases the actuator member toward the locked position and also biases the teeth of the pivotable locking member out of engagement with the teeth on the inner member of the four-bar linkage; Wherein the base end of the actuator member is movable into the first recess of the locking member to allow the teeth of the locking member to move out of engagement with the teeth of the inner member of the four-bar linkage. 65. The armrest assembly of claim 64, comprising: The second lock includes a locking second recess in the locking member that receives the base end of the actuator member and prevents movement of the locking member when downward force is applied to the cushion. 66. The armrest assembly of any one of claims 64 and 65, wherein the first recess comprises a shallow V-shaped surface. 67. The armrest assembly of claim 66, wherein the first recess includes first and second substantially flat surfaces that intersect each other to define a corner of the shallow V-shaped surface, and wherein the locking A second recess is formed in the first substantially flat surface at a location spaced from the corner. 68. An armrest assembly as claimed in any one of claims 64-67, wherein the spring comprises a leaf spring. 69. An armrest assembly as claimed in any one of claims 64-68, wherein the base end of the actuator member is pointed. 70. The armrest assembly of any one of claims 65-69, wherein the actuator member is pivotally connected to the upper member, and when the base end of the actuator member engages the locking second recess , the actuator part forms a rigid triangular linkage with the upper part and the inner part. 71. A chair assembly comprising; a seat support structure comprising a seat support surface configured to support a seated occupant thereon; an armrest assembly comprising an arm support surface for supporting an arm of a seated user thereon; an arm support assembly having an upper end supporting the arm support assembly at a higher vertical elevation than the seat support surface and a lower end including a selected one of a pivot boss and a pivot aperture; and an arm support structure comprising the other of a pivot boss and a pivot aperture, wherein the pivot boss is received in the pivot aperture to pivotally support the arm support assembly about a pivot point between a first position and Rotating between the second position, the pivot boss has a conical shape, and wherein the aperture has a conical shape that closely corresponds to the shape of the pivot boss. 72. The chair assembly of claim 71, wherein the arm support structure includes the pivot aperture. 73. The chair assembly of any one of claims 71 and 72, wherein friction is applied between the pivot boss and the pivot aperture to maintain the arm support assembly in the first position and the second position. A selected position between the two positions, and wherein the four-bar linkage is not held in the selected position by any other mechanical means other than the frictional force. 74. The chair assembly of any one of claims 71-73, wherein the pivot boss and pivot aperture are biased toward each other. 75. The chair assembly of any one of claims 71-74, wherein the pivot boss and pivot aperture are biased toward each other by a spring member. 76. The chair assembly of claim 75, wherein the spring member comprises a coil spring. 77. The chair assembly of any one of claims 75 and 76, further comprising: An adjustment mechanism that adjusts the amount of biasing force exerted by the spring member. 78. The chair assembly of any one of claims 71-77, further comprising: a bushing member positioned between the pivot boss and the pivot aperture. 79. The chair assembly of claim 78, wherein the bushing member has a conical shape that generally corresponds to the shape of the pivot boss and the shape of the pivot aperture. 80. The chair assembly of any one of claims 71-79, wherein the arm support assembly includes a four-bar linkage that permits vertical height adjustment of the armrest assembly relative to the seat support structure. 81. The chair assembly of any one of claims 71-80, wherein the armrest assembly is pivotally adjustable relative to the upper portion of the arm support assembly. 82. The chair assembly of any one of claims 71-81, wherein the armrest assembly is longitudinally adjustable relative to the upper portion of the arm support assembly. 83. The chair assembly defined in any one of claims 71-82, wherein the arm support assembly moves greater than or equal to about 38° between the first position and the second position. 84. The chair assembly of any one of claims 71-83, wherein the seat support surface includes a longitudinal axis, and wherein the arm support assembly moves outwardly from an axis parallel to the longitudinal axis of the seat support surface by greater than or equal to about 22°. 85. The chair assembly of claim 84, wherein the arm support assembly moves greater than or equal to about 17° inwardly from the axis parallel to the longitudinal axis of the seat support surface. 86. The chair assembly of any one of claims 71-83, wherein the seat support surface includes a longitudinal axis, and wherein the arm support assembly moves inwardly from an axis parallel to the longitudinal axis of the seat support surface by greater than or equal to about 17°. 87. A chair assembly comprising; an arm support assembly with an upper end and a lower end; an armrest assembly adapted to support the arm of a seated user thereon and supported on the upper end of the arm support assembly; an arm support structure pivotally supporting the arm support assembly for pivotal movement about a substantially vertical axis such that the upper end of the arm support assembly is movable about the substantially vertical axis between a first position and a second position pivoting, the second position is laterally outboard of the first position; and a seat support structure comprising a seat support surface configured to support a seated user thereon; wherein the seat support surface includes a longitudinal axis; and wherein the upper end of the arm support assembly is displaced greater than or equal to about 22° outward from an axis parallel to the longitudinal axis of the seat support surface, and wherein the upper end of the arm support assembly is displaced inward from the axis parallel to the longitudinal axis of the seat support surface The movement is greater than or equal to about 17°. 88. The chair assembly of claim 87, wherein the arm support assembly comprises a four-bar linkage assembly comprising: a first linkage member having a first end and a second end; a second linkage member having a first end and a second end; The third link member has a first end and a second end, the first end is pivotally coupled to the first end of the first link member to rotate about the first pivot point, and the second end is pivotally coupled to the first end of the first link member. coupled to the first end of the second linkage member for rotation about a second pivot point; and a fourth link member having a first end and a second end, the first end is pivotally coupled to the second end of the first link member to rotate about a third pivot point, the second end is pivotally coupled to the second end of the second linkage member for rotation about a fourth pivot point; Wherein the lower end of the arm support assembly is adjustable between a raised position and a lowered position. 89. The chair assembly of claim 88, wherein the first linkage member includes a U-shaped cross-sectional configuration along a length thereof. 90. The chair assembly of claim 89, wherein the second link member includes a U-shaped cross-sectional configuration along a length thereof, and wherein the first link member and the second link member cooperate to form a U-shaped cross-sectional configuration along the first and second links. The length of the linkage member extends longitudinally to the internal passage. 91. The chair assembly defined in any one of claims 88-90, wherein the third linkage member includes at least a portion of an arm support structure. 92. The chair assembly defined in any one of claims 88-91, wherein the fourth linkage member includes at least a portion of an armrest assembly. 93. The chair assembly of any one of claims 87-92, wherein the lower end of the arm support assembly includes a selected one of a pivot boss and a pivot aperture, and the arm support structure includes a pivot boss and a pivot aperture. The other one of the pivot hole, and wherein the pivot boss is received by the pivot hole to pivotally support the arm support assembly. 94. The chair assembly of claim 93, wherein the pivot boss is conical, and wherein the pivot aperture is conical and cooperatively receives the pivot boss therein. 95. The chair assembly of any one of claims 93 and 94, wherein the arm support structure includes the pivot aperture. 96. The chair assembly of any one of claims 93-95, wherein friction is applied between the pivot boss and the pivot aperture to maintain the arm support assembly in the first position and the second position. A selected position between the two positions, and wherein the arm support assembly is not held in the selected position by any other mechanical means other than the frictional force. 97. The chair assembly of any one of claims 93-96, wherein the pivot boss and pivot aperture are spring biased toward each other. 98. The chair assembly of one of claims 96 and 97, wherein the frictional force is adjustable by mechanical means. 99. The chair assembly of any one of claims 90-98, further comprising: a locking assembly actuatable between a locked position in which the four-bar linkage is locked in a selected vertical position and an unlocked position in which the four-bar linkage can be raised and lowered are adjusted between the positions. 100. The chair assembly of claim 99, wherein the third linkage member includes at least a portion of a locking assembly. 101. The chair assembly of any one of claims 87-100, wherein the armrest assembly is pivotally adjustable relative to the upper portion of the arm support assembly. 102. The chair assembly of any one of claims 87-101, wherein the armrest assembly is longitudinally adjustable relative to the upper portion of the arm support assembly. 103. The chair assembly of any one of claims 88-102, wherein the four-bar linkage assembly adjusts between the raised position and the lowered position by greater than or equal to about 35°. 104. The chair assembly of any one of claims 88-103, wherein the upper end of the four-bar linkage assembly moves greater than or equal to about 38° between the first position and the second position.