JP4796087B2 - Tilt device such as backrest in chair - Google Patents

Description

  The present invention relates to a backrest and seat tilting device for a chair.

As a conventional device of this type, for example, as described in Patent Document 1 related to the application of the present applicant, a backrest supporting rod that supports the backrest is supported on a support base supported by legs. It is pivotally mounted so that it can be tilted, and the seat is mounted so that it can be moved rearward and downward by means of a guide with a long hole and a pin, etc. In some cases, the seat moves backward and downward in conjunction with the back tilt of the backrest.
Japanese Utility Model Publication No. 2001-128786

  However, in the conventional apparatus as described above, the structure is complicated, the assembling work is complicated, and the support mechanism of the seat is concentrated in the central part below the seat, and the appearance is good, but the wide seat When wearing, there are problems such as poor seat stability.

  In view of the above-mentioned problems of the conventional technology, the present invention has a simple structure, is easy to assemble, and can stably support a wide seat. The object is to provide a tilting device such as drooling.

According to the present invention, the above problem is solved as follows.
(1) A front end of a lower portion facing forward in a pair of left and right back support rods supporting the backrest is pivotally attached to a support supported by the legs with a shaft pointing in the left and right directions, and the back support urges the lever in a direction backrest is upright, the slightly rear portion from the pivot portion in both backrest support rod is provided with a seat support member extending outwardly upwardly integrally with the seat The upper end portion of the support piece is positioned inward from the inner side surface of the rear portion of the pair of left and right seat support rods facing the front-rear direction for supporting the seat, and the upper end portion of the seat support piece and the front portion of the support base an upper end portion of a pair of right and left support links facing pivotally connected with the right and left direction axis upward, with the axis oriented in the left and right direction rear and the front of the seat supporting rod of the left and right pair by pivotally Support the seat so that it moves backward and downward in conjunction with the back tilt of the backrest. .

  With such a configuration, the seat support piece for supporting the rear part of the seat is directly provided on the back support rod and the linkage between the backrest and the seat is intended, so the structure is simple and the assembling work is easy. Moreover, the seat can be stably supported by the pair of support links and the pair of seat support pieces.

  (2) In the above paragraph (1), the supporting base is provided with urging means for urging the backrest support ridge in the direction in which the backrest stands up, and is attached in the direction in which the support link stands up. A supplementary biasing means is provided.

  With such a configuration, the urging means for directly urging the support link can assist the urging means for urging the backrest support rod, and can reliably return the front portion of the seat forward.

  (3) In the above item (2), the auxiliary urging means is a torsion that urges the supporting link in the direction of standing up the support link having the lower end pivotally attached to the front portion of the support base with the shaft facing the left-right direction. A coil spring is used.

  With such a configuration, the structure of the auxiliary biasing means can be simplified.

  (4) In the above item (3), the torsion coil spring is disposed in an outward tube portion provided at the front portion of both side walls of the support base.

  With such a configuration, the structure can be simplified.

  According to the present invention, it is possible to provide a tilting device such as a backrest in a chair that has a simple structure and is easy to assemble and that can stably support a wide seat.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
1 to 11 show a chair provided with an embodiment of the present invention.

  As shown in FIGS. 1 and 2, the chair includes a leg body (3) having five radial rods (2) each having a caster (1) provided at the tip. In the center of the leg (3), a telescopic leg column (4) provided with a gas spring (not shown) is erected, and at the upper end of the leg column (4), the rear part of the support base (5) Is fixed.

  The support base (5) has a substantially hollow box shape with an open bottom surface, and the opening on the bottom surface is covered with a removable cover (6).

  Inside the support base (5), there are urging means (9) (see FIG. 4) for returning the backrest (7) and the seat (8), which will be described later, and means for switching the urging force (10) (FIG. 6). However, as will be described in detail later, the schematic configuration of the backrest and seat tilting device (A) will be described with reference to FIGS. To do.

A hexagonal columnar shaft (11) facing in the left-right direction is passed through the middle portion of the support base (5) in the front-rear direction so as to be rotatable about its central axis.
A pair of left and right backrests that are substantially L-shaped in a side view supporting the backrest (7) are attached to both ends of the shaft (11) projecting left and right from both side walls (5a) and (5a) of the support base (5). A cylindrical portion (12a) (12a) facing the left-right direction provided at the front end of the support rod (12) (12) is fixedly fitted, and the backrest (7) and the backrest support rod (12) (12) are The shaft (11) and the shaft (11) can be tilted rearward and downward about the shaft (11).
(13) is a headrest provided at the upper end of the backrest (7), and (14) is an armrest provided so as to stand in the middle of the lower part facing the front of the left and right backrest support ridges (12). is there.

A seat support piece (15) that extends outward and upward is integrally provided at an intermediate portion between the cylindrical portion (12a) and the armrest (14) in the left and right backrest support rods (12). As shown in FIG. 3, the upper end of each seat support piece (15) faces the left and right pair of guide rails (seat support rods) (16) facing in the front-rear direction, and faces in the left-right direction. It is connected with a shaft (17).

  As shown in FIG. 3, the front portions of the left and right guide rails (16), (16) are connected to each other with a horizontal rod (18) facing in the left-right direction. The upper ends of a pair of left and right support links (19) and (19) that are substantially directed in the vertical direction are connected to the outside of the connection portion with the flange (18) with a shaft (20) that is directed in the horizontal direction.

The lower ends of the left and right support links (19) and (19) are located outside the outwardly facing cylindrical portions (21) and (21) provided at the front portions of both side walls (5a) and (5a) of the support base (5). 2 is rotated counterclockwise in FIG. 2 by a torsion coil spring (23) (see FIG. 6) which is pivotally attached with one shaft (22) facing left and right and provided in each cylindrical portion (21). It is energized.
An operation lever (24) for adjusting the urging force of the urging means (9) is fixedly fitted to the end of the shaft (22) outside the left support link (19).

  The left and right guide rails (16) and (16) have a pair of left and right movable rails facing the front and rear, with short leg pieces (25) and (25) fixed to the lower surface of the seat (8). (26) (26) is mounted so that the position can be adjusted in the front-rear direction. Note that the longitudinal position adjustment mechanism of the seat (8) is not directly related to the present invention and will not be described in detail.

Thus, the back support rod (12), the seat support piece (15) integral therewith, the support link (19), the torsion coil spring (23), and the return that will be described below are provided inside the support base (5). The urging means (9), the urging force switching means (10), and the like form a backrest and seat tilting device (A), and the backrest (7) and the backrest support ridge (12 ) (12) is tilted rearward and downward about the axis (11), the back support rod (12) (12) and the seat support piece (15) (15) integrated with the back tilt at that time, The rear part of the seat (8) is moved rearward and downward, and in conjunction with this, the front part of the seat (8) is also connected to the left and right support links (19) and (19) by the torsion coil springs (23) and (23). By tilting backward against the urging force, it can be moved slightly rearward and downward.
In this example, the left and right torsion coil springs (23) and (23) are auxiliary to the return biasing means (9) provided inside the support base (5).

  As shown in FIG. 4, the urging means (9) provided in the support base (5) is composed of a plurality (three in this example) of unit urging means (27) (28) (29). Each unit urging means (27) (28) (29) is a substantially cylindrical core member provided with a hexagonal hole (30) in the center of which the above hexagonal columnar shaft (11) is fitted so as not to be relatively rotatable. (31) and the core material (31) are substantially concentric with each other, and a protrusion (32) projecting from the outer peripheral surface comes into contact with the support base (5) or the switching means (10). 5) Filled between the outer cylinder (33) that is prevented from rotating with respect to the outer cylinder (33) and the core material (31) and the outer cylinder (33). And a cylindrical elastic body (34) made of rubber or a soft synthetic resin material that is elastically deformed by rotating around the central axis and imparts a restoring force to the core material (31). ing.

The central unit biasing means (28) is designed to have a larger biasing force by making the axial length longer than the left and right unit biasing means (27) (29), and The left unit urging means (27) is elastic so that the elastic coefficient of its elastic body (34) is larger than that of the elastic body (34) in the other unit urging means (28) (29). By making the material of the body (34) different from that of the other unit urging means (28) and (29), the urging force is minimized.
Therefore, in this example, the biasing force is set to gradually increase in the order of the left unit biasing means (27), the right unit biasing means (29), and the central unit biasing means (28). It is.

  The protrusion (32) of the outer cylinder (33) in the central unit biasing means (28) is always on the stop piece (35) hanging from the lower surface of the front center of the upper wall (5b) of the support base (5). They are in contact (see FIG. 7).

  A hexagonal hole (36) is cut in the center between the outermost unit urging means (27) (29) and both side walls (5a) (5a) of the support base (5). A pair of left and right discs (38) and (38) provided with a downwardly projecting piece (37) at the bottom are arranged so that their hexagonal holes (36) are fitted to the shaft (11) so that they cannot be rotated relative to each other. It is installed.

  The upper part of the right disc (38) projects upward through a long hole (39) facing the front-rear direction formed on the right side of the upper wall (5b) of the support base (5), and the inner surface A sectoral sector gear (41) having a fan-shaped side view formed with radial teeth (40) is continuously provided.

  The sector gear (41) is provided with a central unit biasing means (28) on the backrest (7) even when the backrest (7) is stopped at the most upright position (hereinafter referred to as the initial position). It has a function for applying a force (initial twisting force) and a function for locking the backrest (7) at an arbitrary rearward tilt position.

    That is, from the state where the protrusion (32) of the outer cylinder (33) in the central unit biasing means (28) is in contact with the stop piece (35), the sector gear (41) together with the shaft (11) in FIG. While rotating clockwise by a predetermined initial twist angle, the rear end of the stop plate (42) is brought into contact with the front edge of the sector gear (41) to support the stop plate (42). 5) With the set screw (43) fixed to the upper surface of the upper wall (5b), the shaft (11) is applied with the initial twisting force of the central unit biasing means (28). ) Can be kept counterclockwise in FIG.

Further, in this state, the cylindrical portions (12a) and (12a) of the backrest support rods (12) and (12), which are the initial positions, are fitted and fixed to the both ends of the shaft (11), thereby fixing the initial positions. The initial twisting force by the central unit biasing means (28) can be applied to the backrest (7).
The function of locking the backrest (7) in the sector gear (41) at an arbitrary backward tilt position will be described later.

  The downward projecting pieces (37) and (37) in the left and right disks (38) and (38) are provided below the outer peripheral surface of each outer cylinder (33) in the outermost unit urging means (27) and (29). The locking plate (46) fixed to the pedestal (44) with a set screw (45) (45) is engaged with a portion protruding outward from the outer cylinder (33).

  The discs (38) (38) and the locking plate (46) are the same as those applied to the outermost unit biasing means (27) (29) and the central unit biasing means (28). This is for applying an initial twisting force.

  That is, in the outermost unit biasing means (27) (29), the outer cylinder (33) is the same angle as the initial twist angle of the central unit biasing means (28) with respect to the shaft (11). Only when the locking plate (46) is rotated counterclockwise in FIG. 8, the projecting piece (37) of the disc (38) is engaged with the outer end of the locking plate (46). 33), by fixing with a set screw (45) (45) to the pedestal (44) on the outer peripheral surface of the outer peripheral surface, an initial twisting force similar to that applied to the central unit biasing means (28) is provided on the outermost side. These unit urging means (27) and (29) can also be provided.

As described above, in all the unit urging means (27) (28) (29), the outer cylinder (33) is twisted with respect to the shaft (11) by the same initial torsion angle, respectively, so that the backrest is When (7) is stopped at the initial position, the positions of the protrusions (32) of the outer cylinder (33) in all the unit urging means (27) (28) (29) are aligned.
Thus, in the state where the protrusion (32) of the outer cylinder (33) in the central unit biasing means (28) is in contact with the stop piece (35), the other unit biasing means (27) (29) The protrusion (32) of the outer cylinder (33) is positioned above the central protrusion (32), and there is a risk of malfunction such as preventing the movement of the operation member in the left-right direction in the switching means (10) described later. This can be prevented, and the operation of the switching means (10) becomes convenient.

  As shown in FIG. 6, the switching means (10) is externally fitted to a shaft (22) that can be rotated by the operation lever (24) described above and to be slidable in the left-right direction on the shaft (22). The stop piece (47) protruding rearward and the left and right unit urging means (27) (29) can contact the protruding portion (32) of the outer cylinder (33) and the outside thereof. A pair of left and right actuating members (48), (48) that are movable to a non-actuated position disengaged in the direction, and are fixedly fitted to the shaft (22). As the shaft (22) rotates, the left and right actuating members (48) A pair of left and right cylindrical cams (moving members) (49) and (50) that move the inward inwardly independently of each other, and loosely fitted on the shaft (22), and left and right actuating members A compression coil spring (51) which is compressed between (48) and (48) and urges the left and right actuating members (48) and (48) away from each other, and both side walls (5a) of the support base (5) ( 5a) is installed between the front and lower parts, and the stop pieces (47) of the left and right actuating members (48) and (48) are connected to the upper wall (5b) of the support base (5). Sandwiched from above and below and is provided with a detent of the actuating member (48), and a guide bar (52) to fulfill a guide for the horizontal movement.

The shapes of the cam surfaces (49a) and (50a) of the left and right cylindrical cams (49) and (50) are determined as shown in the developed view of FIG.
That is, when the operating lever (24) is set to a predetermined 0 ° position, the left and right actuating members (48) and (48) are both in the inoperative position. From this state, the operating lever (24) Is rotated to the 90 ° position, only the left actuating member (48) is pushed rightward against the urging force of the compression coil spring (49), and is positioned at the actuating position. The right actuating members (48) and (48) are located in the inoperative position as they are.

  When the operating lever (24) is further rotated to the 180 ° position from that state, the left and right actuating members (48) and (48) are both moved to the left, and the left actuating member (48) The non-actuated position and the right actuating member (48) are located in the actuated position.

  Furthermore, when the operation lever (24) is rotated to the 270 ° position from that state, only the left operating member (48) is moved to the right, and the left and right operating members (48) (48). Are both located in the operating position.

  While the operating lever (24) is rotated from the 270 ° position to the 360 ° position, that is, the 0 ° position, the left and right actuating members (48) and (48) are moved to each other by the urging force of the compression coil spring (51). Both are moved outward and are both in the inoperative position.

  Therefore, when the operating lever (24) is rotated from the 0 ° position to the 270 ° position, the urging force for returning the backrest (7) is minimum when it is 0 ° (central unit urging means (28 )), Slightly smaller at 90 ° (sum of the urging force of the central unit urging means (28) and the urging force of the left unit urging means (27)), slightly at 180 ° Large (sum of urging force of central unit urging means (28) and urging force of right unit urging means (29)), maximum at 270 ° (all unit urging means (27) (28) (The sum of the urging powers of (29)) increases gradually.

  On the other hand, while the operating lever (24) is rotated from the 0 ° position to the 270 ° position, the distance between the left and right actuating members (48) and (48) gradually decreases gradually, and the compression coil spring ( 51) The operating resistance of the operating lever (24) gradually increases step by step, so that when the operating resistance of the operating lever (24) increases, it is necessary to restore the backrest (7). You can sensibly know that the urging force is also great.

As shown in FIG. 5, on the upper surface of the upper wall (5b) of the support base (5), there is a case (54) for accommodating locking means (53) for locking the backrest (7) at a desired rearward tilt angle. It is provided integrally.
In the case (54), an upper surface and both left and right side surfaces are opened, and an accommodation groove (55) is formed which includes a wide portion (55a) in the right half and a narrow portion (55b) in the left half. In the widened portion (55a), two locking plates (56) (57) having teeth (56a) (57a) meshing with the teeth (40) of the sector gear (41) at the right end are stacked vertically. And are slidable in the left-right direction independently of each other.

  The teeth (56a) and (57a) of the upper and lower locking plates (56) and (57) are formed so as to be shifted back and forth by a half pitch, so only one of the teeth (40) of the sector gear (41) Are designed to mesh.

  A square hole (58) that is long in the left-right direction and penetrates in the up-down direction is formed in the center of each locking plate (56) (57). Similarly, the lower surface of the left side portion communicates with the square hole (58). A U-shaped groove (59) facing in the left-right direction is formed.

  On the right side of the narrow width portion (55b), a partition plate (61) cut downward from the center portion of the lid plate (60) that closes the entire upper surface of the case (54) is fitted from above. The partition plate (61) is formed with a U-shaped groove (62) from the upper end to the vicinity of the lower end.

On the left side of the partition plate (61) in the narrow width portion (55b), a rectangular tube-shaped connecting piece (63) facing in the vertical direction is fitted so as to be slidable in the horizontal direction.
In the center of the right side wall of the connecting piece (63), U-shaped grooves (64) (65) are formed symmetrically from the upper and lower edges toward the middle position, and at the center of the upper edge of the left side wall, A U-shaped groove (66) facing downward is formed.

  U-shaped grooves (59) (59) in the upper and lower locking plates (56) (57), U-shaped grooves (62) in the partition plate (61), and upper and lower U-shaped in the right side wall of the connecting piece (63) A pair of upper and lower rods (67) and (68) facing the left and right direction having enlarged diameter flanges (67a) and (68a) at both ends are slidably fitted in the grooves (64) and (65). ing.

  Between the right-side expanded diameter rod (67a) (68a) of the upper and lower rods (67) (68) and the left end surface of the square hole (58) in the upper and lower locking plates (56) (57), The compression coil springs (69) (69) loosely fitted on the rods (67) (68) are respectively contracted, and the left end surfaces of the upper and lower locking plates (56) (57) and the partition plates (61 The compression coil springs (70), (70) loosely fitted to the rods (67), (68) are respectively contracted between the right side surfaces.

  The magnitude of the urging force between the compression coil spring (69) and the compression coil spring (70) is almost the same, or the compression coil spring (69) is set to be slightly larger than the compression coil spring (70). It is preferable to keep it.

  The U-shaped groove (66) on the left side wall of the connecting piece (63) has a pull lock / pull release mechanism (71) provided further to the left than the connecting piece (63) in the narrow width portion (55b). The right end portion of the shaft (72) provided with the expanded diameter rod (72a) is fitted.

  In the pull lock / pull release mechanism (71), the shaft (72) penetrates the rectangular tube case (73) provided in the narrow portion (55b) in the left-right direction, and the shaft (72) is passed through the case ( 73) Once pulled to the left from the left end side protruding from the left end, a known rotary repetitive locking mechanism provided in the case (73), similar to the so-called knock type ballpoint pen, Next, when the shaft (72) is pulled to the left again, the locking state of the rotary repetitive locking mechanism is released, and the return spring (built in the case (73) ( When the shaft (72) is moved to the right by the (not shown) and thereafter the shaft (72) is pulled to the left, the rotary repetitive locking mechanism alternately repeats the locked state and the unlocked state. It is like that.

  The left / right movement stroke of the shaft (72) is such that one of the teeth (56a) (57a) of the two locking plates (56) (57) meshes with the tooth (40) of the sector gear (41). This is greater than the required travel.

  The left end of the shaft (72) has a cable (75) inserted through the flexible sheath tube (74), and an operating lever (76) provided on the lower surface of the front end of one armrest (14) ( The shaft (72) is pulled to the left whenever the operating lever (76) is rotated upward.

  When the locking means (53) is assembled to the support base (5), the locking plates (56) (57), the connecting pieces (63), the rods (67) ) (68), compression coil springs (69) (70), and pull lock / pull release mechanism (71) are all reversed and assembled in sequence, then they are integrated and reversed while the housing groove ( 55) should be fitted.

  As shown in FIG. 10, when the shaft (72) is pulled to the left and locked, the connecting piece (63) is moved to the left by the enlarged diameter rod (72a) at the right end thereof. Along with this, the upper and lower rods (67) (68) are also moved to the left, and normally the upper and lower locking plates (56) (57) are balanced by the balance of the urging forces of the compression coil springs (69) (70). ) Is stopped at the inoperative position where the teeth (56a) and (57a) are disengaged leftward from the teeth (40) of the sector gear (41).

  In this state, the backrest (7) is always urged toward the standing position by the urging force adjusted by the operating lever (24), and is pushed back against the urging force. It can be tilted backward with the resistance of.

  In this state, after tilting the backrest (7) to a desired angle and then rotating the operating lever (76) upward, the shaft (72) is once moved to the left, and a pull lock / pull release mechanism ( 71) is released, and the shaft (72) is moved to the right as shown by the solid line in FIG. 11, and accordingly, the connecting piece (63), the upper and lower rods (67) (68), and the upper and lower The locking plates (56) and (57) are moved to the right by the balance of the urging forces of the compression coil springs (69) and (70), and one of the upper and lower locking plates (56) and (57) The teeth (56a) (57a) mesh with the teeth (40) of the sector gear (41).

  If they do not mesh immediately, if the backrest (7) is slightly tilted back and forth, any of the teeth (56a) (57a) will always mesh with the teeth (40) of the sector gear (41). .

  After any tooth (56a) (57a) (upper tooth (56a) in FIG. 11) meshes with the tooth (40) of the sector gear (41), the backrest (7) is locked in its position, Even if the seated person leaves his back from the backrest (7), the backrest (7) does not move forward or backward from that position.

  When the back lever (7) is locked and the control lever (76) is turned upward again, the pull-lock / pull release mechanism (71) is moved to the left after the shaft (72) is once moved to the left. It is locked and the shaft (72) is locked in a state of being moved to the left, and accordingly the teeth of the connecting piece (63), the upper and lower rods (67) (68), and the sector gear (41) One of the upper and lower locking plates (56) and (57) (in this example, the lower locking plate (57) in this example) not engaged with (40) is moved to the left.

However, the large urging force by the urging means (9) is applied to the locking plate (56) (or (57)), which is meshed with the teeth (40) of the sector gear (41), in a substantially perpendicular direction. However, it does not immediately disengage from the sector gear (41), but only when a load against the urging force is applied, such as when a seated person leans on the backrest (7), it disengages from the sector gear (41). Then, it is moved to the left by the balance of the urging forces of the compression coil springs (69) and (70).
The upper and lower locking plates (56) and (57) are not directly connected to the upper and lower rods (67) and (68), but are provided with play by interposing compression coil springs (69) and (70) in both the left and right directions. This is why.

  As is apparent from the above, according to this embodiment, the urging force for returning the backrest (7) can be adjusted stepwise over a large range by rotating the operation lever (24). At the same time, the backrest (7) can be locked at a desired rearward tilt angle or released from the locked state by the operation lever (76).

  The unit urging means may be two or four or more, and all the urging forces can be selected and transmitted to the backrest or the seat.

It is a front view of a chair provided with one embodiment of the present invention. Similarly, it is a side view. Similarly, it is a cross-sectional plan view along line III-III in FIG. Similarly, it is a disassembled perspective view of a support base and urging means inside thereof. Similarly, it is a disassembled perspective view of a support base and the locking means of the upper part. FIG. 3 is an enlarged cross-sectional plan view taken along line VI-VI in FIG. 2. Similarly, it is a vertical side view along the VII-VII line of FIG. Similarly, it is a vertical side view along the VIII-VIII line of FIG. Similarly, it is a development view of the cam surfaces of the left and right cylindrical cams in the switching means. Similarly, it is a schematic plan view showing the unlocked state of the locking means. Similarly, it is a schematic plan view showing the locked state of the locking means.

Explanation of symbols

(A) Tilt device
(1) Casters
(2) Legs
(3) Leg
(4) pedestal
(5) Support base
(5a) Side wall
(5b) Upper wall
(6) Cover
(7) Backrest
(8) Seat
(9) Energizing means
(10) Switching means
(11) axis
(12) Back support
(12a) Tube part
(13) Headrest
(14) Armrest
(15) Seat support piece
(16) Guide rail (seat support rod )
(17) Axis
(18) Yokohama
(19) Support link
(20) axis
(21) Tube part
(22) Axis
(23) Torsion coil spring (biasing means)
(24) Control lever
(25) Leg piece
(26) Movable rail
(27) (28) (29) Unit biasing means
(30) Hexagon hole
(31) Core material
(32) Projection
(33) Outer cylinder
(34) Elastic body
(35) Stop piece
(36) Hexagon hole
(37) Projection
(38) Disc
(39) Long hole
(40) Teeth
(41) Sector gear
(42) Stop plate
(43) Set screw
(44) Pedestal
(45) Set screw
(46) Locking plate
(47) Stop piece
(48) Actuating member
(49) (50) Cylindrical cam (moving member)
(49a) (50a) Cam face
(51) Compression coil spring
(52) Guide bar
(53) Locking means
(54) Case
(55) Accommodation groove
(55a) Widening part
(55b) Narrow part
(56) (57) Locking plate
(56a) (57a) teeth
(58) Square hole
(59) U-shaped groove
(60) Lid plate
(61) Partition plate
(62) U-shaped groove
(63) Connection piece
(64) (65) (66) U-shaped groove
(67) (68) Rod
(67a) (68a)
(69) (70) Compression coil spring
(71) Pull lock / pull release mechanism
(72) Shaft
(72a) Diameter expansion 鍔
(73) Case
(74) sheath tube
(75) Cable
(76) Control lever

Claims (4)

A pair of left and right backrest supporting saddles that support the backrest are pivotally attached to a support supported by the legs with a front axis that faces forward, with a shaft that faces left and right. rest is urged toward the direction of standing, the both backrest support slightly rearward part than the pivot portion in the rod, is provided a seat support member extending outwardly upwardly integrally, the seat support member The upper end portion is positioned inward from the inner surface of the rear portion of the pair of left and right seat support rods facing the front-rear direction supporting the seat, and the upper end portion of the seat support piece and the front portion of the support base are arranged in the left-right direction. an upper end portion of a pair of right and left support links facing upward pivotally connected with a shaft, by pivotally each with an axis oriented in the lateral direction rear and the front of the seat supporting rod of the right and left pair, a seat , Supported in such a way that it moves backward and downward in conjunction with the back tilt of the backrest. Tilting device such as a backrest in the chair, wherein.   A biasing means for biasing the backrest support rod in the direction in which the backrest stands is provided in the support base, and an auxiliary biasing means for biasing in the direction in which the support link stands is provided. A tilting device such as a backrest in the chair according to claim 1.   The chair according to claim 2, wherein the auxiliary biasing means is a torsion coil spring that biases the support link having the lower end pivotally attached to the front portion of the support base with a shaft facing in the left-right direction. Tilting device such as backrest.   4. A tilting device for a backrest or the like in a chair according to claim 3, wherein the torsion coil spring is disposed in an outward tube portion provided at a front portion of both side walls of the support base.

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