JP6185231B2 - Chair - Google Patents

Description

  The present invention relates to a chair in which a backrest is attached to left and right support frames, and is particularly suitable for a rocking chair whose backrest can be tilted backwards (turnable).

  When the backrest of the chair is configured to be tiltable rearwardly, generally, the tilting frame is connected to a seat or a support base so as to be tiltable rearwardly, and the backrest is often attached to the tilting frame. The pivoting fulcrum of the tilting frame may be configured with a simple shaft or may be configured with a torsion bar as disclosed in Patent Document 1. Further, in a chair in which the backrest does not tilt backward, it is widely performed that the backrest is disposed between the left and right support frames and the backrest is fastened to the support frame with screws.

Japanese Patent No. 3730119

  Now, when the backrest is turned, if the tilting frame is used as in Patent Document 1, the backrest moves away from the seat so that it tilts backward. For example, when the chairs are used side by side, If the interval is narrowed, the head and shoulders of the seated person may move greatly backwards when rocking, which may be annoying to the person behind. On the other hand, when the backrest is connected to the support frame so as to tilt about the middle part in the vertical direction, there is an advantage that the head of the seated person can be prevented from largely moving backward while ensuring a large rearward tilt angle.

  The present invention has been made against the background of the present situation, and an object of the present invention is to make it easy to connect the backrest in a chair in which the backrest is connected to the left and right support frames.

The present invention is specified in each claim. Of these, the invention of claim 1 has a support frame disposed on the left and right outer sides of the seat, and a backrest attached to the support frame at a height position higher than the seating surface. A structure in which a support shaft having a direction axis and a pair of bearing portions are connected to the support frame, a support shaft is provided on one of the backrest and the support frame, and a bearing portion is provided on the other And the notch which fits in the said spindle is provided in the said bearing part by moving the said backrest from back to back.

  According to a second aspect of the present invention, in the first aspect, the backrest is tiltable rearwardly, and a resin bush is interposed between the support shaft and the bearing, and the bush is attached to the support shaft in advance. In this state, the backrest is attached, and the bearing portion and the support shaft are held by screws so as not to be detached.

According to a third aspect of the present invention, in the second aspect of the present invention, the bush is provided with an outward stopper piece that fits into the notch of the bearing, and when the stopper piece fits into the notch , the bush It is held so that it cannot rotate relative to the bearing.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the backrest is tiltable rearward and the seat is movable back and forth, and the seat or a seat receiving body to which the seat is attached is movable. While a passive arm pointing upward is provided at the rear end, a pocket-shaped pushing portion that is fitted to the passive arm from above is formed at the lower end of the backrest, and the backrest tilts backward. and the seat passively arm is pressed so as to move forward by the pressing portion and the backrest, by backward movement while a person is inclined forward than the reference posture without leaning, The fitting of the bearing portion and the support shaft and the fitting of the pushing portion with respect to the passive arm are performed in series.

  In the present invention, since the support shaft and the bearing portion are fitted together by moving the backrest backward, there is no need to insert the pin one by one, and therefore the backrest can be quickly attached. Further, since the backrest is connected to the support frame at a position higher than the seating surface, when applied to a backward tilting rocking chair as in claim 2, the head and shoulders are locked when locking while securing a large backward tilt angle. Since it is possible to prevent a large backward movement, it is suitable when the chairs are used side by side.

In addition, the use of a bush as in claim 2 is suitable for a rocking chair in which the backrest tilts. Further, by attaching the bush to the support shaft first, the notch of the bearing portion is in an open state , so that the fitting of the bearing portion can be performed without any trouble. When the bush is provided, if the stopper piece is provided as in claim 3, it is possible to prevent rattling of the bush and to prevent deterioration of aesthetics due to exposure of the notch in the bearing portion.

When the seat is moved forward in conjunction with the back tilt of the back as in claim 4 , the lower body of the seated person moves forward during locking, and the body as a whole becomes easier to grow. Can be increased. Accordingly, the tilting fulcrum of the backrest is combined with the position higher than the seating surface, so that the rocking chair is suitable.

And in the standard posture, the notch of the passive arm opens in the front-rear direction, while the pushing part of the backrest opens downward, so simply moving the backrest backwards will move the pushing part to the passive arm. can not Kiga be fitted in, by to rearward movement before leaning posture than the reference posture of the backrest as claimed in claim 4, the mating between the passive arm and the support shaft, pushing to the passive arm The part can be fitted in a series. Therefore, it is possible to easily assemble a chair whose seat moves forward in conjunction with the backrest.

Is a perspective view of the chair according to the implementation embodiments, (A) is an overall perspective view of a state tilted seat, (B) is an overall perspective view of a state in which flipped a seat, (C) is back part of the FIG. The perspective view of the state which isolate | separated the seat, (B) is a perspective view of a seat receiving part. It is a separation perspective view in the state where a seat was omitted. It is a separation perspective view showing a locking mechanism. (A) is a partially separated perspective view of a seat part, (B) is a figure which shows the relationship between a slider and a support stay, (C) is CC sectional view taken on the line of (B). (A) is the isolation | separation perspective view which shows a part of interlocking | linkage part, (B) is the partial front view of an interlocking | linkage part similarly. 6A is a sectional view taken along line AA in FIG. 6B, FIG. 6B is a partially enlarged view of FIG. 6A, and FIG. 10C is a sectional view taken along line BB in FIG. (A) is a side view for showing movement, (B) is a separated side view showing the relationship between the flip-up rotation fulcrum and the pushing position of the support stay. It is a figure which shows the connection part of a backrest main body, (A) is a perspective view of an external appearance, (B) is an isolation | separation perspective view, (C) is a perspective view of the state which isolate | separated the upper cap, (D) is the isolation | separation perspective view of the whole It is. (A) is the plane sectional view cut by the rotation axis, (B) is the separation perspective view. It is a side view which shows the attachment procedure of a backrest. It is a figure which shows the attachment procedure of a backrest, (A) is a side view, (B) is a perspective view.

(1). Outline of Chair Next, an embodiment of the present invention will be described with reference to the drawings. First, an outline of the chair will be described mainly based on FIGS. In the following description, the words “front and rear” and “left and right” are used to specify the direction, but the front and rear and left and right are based on a state viewed from a person who normally sits on a chair. The front view direction is the direction facing the seated person.

  As shown in FIG. 1, the chair includes a leg device 1, a seat 2, and a backrest 3 as large elements, and the seat 2 is attached to a movable base 4 that is flipped up and rotated. Therefore, the seat portion 5 is configured with the seat 2 and the movable base 4 as main elements. As shown in FIG. 1A, the seat 2 includes a resin seat plate (seat inner shell) 6 and a seat cushion material 7 stretched on the upper surface thereof. Covered with material 8. The movable base 4 can also be called a pivoting base or a flip-up base. As shown in FIGS. 2 to 4, a large number of reinforcing ribs 9 are provided on the upper surface of the movable base 4.

  The leg device 1 is made of a metal pipe such as a steel pipe or an aluminum pipe (therefore, this embodiment is applied to a so-called pipe chair), and has four legs having left and right front legs 10 and left and right rear legs 11. It is a method. Casters 12 are attached to the front and rear legs. At the upper end of the front foot 10, an upper side portion 14 extending rearward in a posture slightly tilted forward with respect to the horizontal is formed by bending, and the rear end of the upper side portion 14 is butted against a portion near the upper end of the rear foot 11 and welded. It is fixed with.

  The front ends of the left and right upper side portions 14 are connected by a laterally long horizontal hook 15. The recumbent rod 15 also has a function of supporting the seat portion 5 that has been tilted forward, and is bent gently in an upwardly convex shape in front view so that the left and right intermediate portions are raised. The rear foot 11 is in a forward leaning posture in a side view so as to be shifted toward the front as it goes upward, and is curved with a gentle curvature. As shown in FIG. 1B, a recess 4a is formed on the lower surface of the movable base 4 in which the left and right intermediate portions of the horizontal bar 15 are fitted.

  The upper end of the rear foot 11 is a free end, and the upper support shaft 17 whose axis is horizontally horizontal is fixed to the upper end by welding, and the backrest 3 is attached to the upper support shaft 17 via the upper screw 18 in the rear. It is connected so that it can tilt. Therefore, in the present embodiment, the upper end portion of the rear foot 11 is a support frame 19 as an example of a support member for attaching the backrest 3 and the seat 2. As described above, since the rear foot 11 is tilted forward in a side view, the upper support shaft 17 is positioned in front of the rear end of the seat 2.

  The left / right distance between the left and right hind legs 11 is larger than the left / right distance between the left and right front legs 10, and therefore, the leg devices 1 of the front and rear chairs are fitted together (nested) with the seat portion 5 flipped up. Is possible. For example, as clearly shown in FIG. 3, a stopper 20 made of rubber or the like is provided on the inner side surface of the rear foot 11 so that the front foot 10 of the rear chair hits (fits) when the chair is nested.

  In addition, the form of the leg apparatus 1 can be set arbitrarily. Needless to say, nesting is also possible by making the distance between the left and right front legs 10 larger than the distance between the left and right rear legs 11. Each of the legs 10 and 11 can be manufactured from a solid bar or an elliptical tube. Of course, an aluminum die-cast product or a resin molded product can also be used.

  For example, as shown in FIG. 3, the movable base 4 has a shallow box-shaped main body 21 that is square in plan view, and a square arm 22 that protrudes upward while spreading outward from the rear part of the main body 21. . The movable base 4 is a resin molded product (may be an aluminum die-cast product), and the square arm 22 is provided integrally with the main body 21. In addition, since the main-body part 21 is box-shaped, the outer periphery is comprised with the surrounding wall.

  The square arm 22 is basically a plate that is wide in the front-rear direction, but the front-rear distance decreases as it goes up, and a boss portion (bearing portion) 23 that protrudes outward in the left-right direction is integrally provided at the upper end. The boss 23 is connected to the middle part of the support frame 19 so as to be rotatable by a lower support shaft 24, a lower bush 25 and a lower screw 26. Therefore, the movable base 4 can be swung up and rotated around the axis 27 of the boss portion 23, whereby the seat portion 5 is flipped up (folded) as shown in FIG. A) state. The center of gravity of the seat portion 5 is located behind the axis 27 of the boss portion 23 and the lower support shaft 24 in a state where the seat portion 5 is flipped up. The lower support shaft 24 is fixed to the support frame 19 by welding. The head of the lower screw 26 is covered with a lower cap 28.

  As shown in FIG. 1 (C), the backrest 3 includes a backrest main body (main frame) 29 having a large opening in the front-rear direction, and a support body 30 attached to the backrest main body 29 so as to cover the opening. Yes. Although the back cushion material 31 is stretched on the front surface of the support body 30, the support body 30 may be left exposed without providing the back cushion material 31. The backrest body 29 and the support body 30 are resin molded products.

  An outward projecting portion 29a projecting outward in the left and right directions is formed in a lower portion of the backrest body 29, and a bearing portion 32 that fits the upper support shaft 17 is formed at the outer end of the outward projecting portion 29a. doing. A bush (not shown) is fitted to the bearing portion 32, and the backrest body 29 is held on the upper support shaft 17 so as not to be detached by screwing the upper screw 18 into the upper support shaft 17 from the inside. The head of the upper screw 18 is covered with an upper cap 33. The outward projecting portion 29a protrudes forward in plan view, and therefore the backrest 3 surrounds the seated person's waist from behind.

  When the backrest 3 is viewed in a longitudinal side view, the backrest main body 29 is bent so that the portion of the height position where the outwardly projecting portion 29a is provided is located in the foremost position. The height of the outwardly projecting portion 29a is set to the height of the lumbar region (particularly around the third lumbar vertebra) when an average adult is seated. For this reason, the backrest 3 has a lumbar support function.

  The opening of the backrest main body 29 and the support body 30 form a front view form in which the lower part is rounded and is entirely constricted upward. Except for the peripheral edge portion of the support body 30, a large number of holes are opened side by side in the vertical and horizontal directions. For this reason, it has a lattice-like appearance in which a large number of vertical and horizontal lines cross each other. The peripheral portion of the support body 30 is fitted into the backrest body 29 and attached.

  Needless to say, it is also possible to attach the back cushion material 31 directly or via an inner member to the backrest body 29 as a configuration in which the backrest body 29 is not opened in the front-rear direction. Further, instead of the resin support body 30, a flexible mesh material can be stretched on the backrest main body 29. When the resin-made support body 30 is provided, various modes such as a mode in which horizontally long slits are formed in multiple stages can be adopted. The backrest 3 can also be composed of only the backrest body 29.

  When the backrest 3 tilts backward, the seat 2 moves forward. Accordingly, the seat 2 is attached to the movable base 4 so as to be slidable back and forth. Specifically, as shown in FIGS. 2 to 4, a pair of left and right sliders 36 are attached to the movable base 4 so as to be movable back and forth, and the seat plate 6 is attached to the left and right sliders 36 so as not to move relative to the front and rear. Accordingly, the seat 2 moves relative to the slider 36. As shown in FIG. 4, the forward movement of the slider 36 is elastically supported by a spring 37 (compression coil spring) as an example of an elastic support means. The spring 37 is supported by front and rear spring receivers 38, 39. The front spring receiver 38 is held by the movable base 4 so as not to move forward and backward, and the rear spring receiver 39 is pushed by the slider 36 and moves forward.

  Further, left and right horizontally long support stays 40 made of metal plates are fixed to the rear end portions 36 c of the left and right sliders 36 with screws 41, and upward passive arms 42 are bent at the left and right end portions of the support stay 40. On the other hand, a pocket-like pushing portion (holder portion) 43 that fits on the passive arm 42 of the support stay 40 from above is provided at the lower end portion of the backrest body 29.

  A resin crown member 44 is attached to the upper end of the passive arm 42 as a passive portion. The crown member 44 is for dispersing the reaction force to the pushing portion 43 and smoothing the movement. For example, as shown in FIG. 5, the fixed portion of the slider 36 in the support stay 40 is an upward bulging portion 40a, and the protruding piece 36c of the slider 36 is fixed to a stepped portion 40b formed in the upward bulging portion 40a. doing.

  In the chair of the present embodiment, when the backrest 3 is locked by the seated person's leaning, the slider 36 moves forward via the support stay 40, whereby the seat 2 is synchronized (synchronized) with the locking of the backrest 3. Advance.

  Therefore, although the chair of this embodiment is a chair that can be nested, the seat 2 moves forward in conjunction with the locking of the backrest 3. Since the slider 36 is biased in the backward direction by the spring 37, it is sufficient for the pushing portion 43 to have a function of pushing the passive arm 42. Therefore, for example, the backrest body 29 of the backrest body 29 is not formed in a pocket shape. It is also possible to function as the pushing portion 43 by thickening a part of the lower portion. In the present embodiment, the pushing portion 43 and the passive arm 42 of the support stay 40 constitute interlocking means. The slider 36 and the support stay 42 constitute a seat receiver that can move back and forth, and the seat 2 is attached to the slider 36 and the support stay 42 (the mounting structure will be described later).

  For example, as shown in FIG. 5, the slider 36 has a groove shape with a longitudinal front and a downward opening, and an outward front and rear flange 36 b is bent at the lower end of the left and right side plates 36 a. On the other hand, a pair of front and rear support protrusions 45 that the slider 36 covers are provided on the left and right side portions of the movable base 4, and a roller 46 that is disposed with an axially extending lateral axis at the upper end of the support protrusion 45 can freely roll. It is inserted. The roller 46 is made of a resin having a small friction coefficient such as POM resin, and the slider 36 can be slid back and forth lightly and silently. Two long slot holes 52 are formed on the upper surface of the slider 36, and a claw provided on the front spring receiver 38 is fitted into the long slot hole.

  The left-right displacement of the slider 36 is regulated by an outer guide wall 47 provided on the movable base 4 and front and rear inner guide protrusions 48. A guide stopper 49 is provided on the outer guide wall 47 and the front and rear inner guide protrusions 48 so as to be positioned on the front and rear flanges 36 b of the slider 36. For this reason, the slider 36 is held so as to be slidable back and forth without being movable upward. While there is a large space between the front and rear flanges 36b of the slider 36, there is also a large space between the front and rear guide stoppers 49.

(2). Seat Pushing Mechanism Next, the seat pushing mechanism accompanying locking will be described mainly with reference to FIGS. As shown in FIGS. 6 and 7, the resin-made crown member 44 is attached to the upper end of the passive arm 42 in the support stay 40 as described above. The crown member 44 has a substantially circular shape in a side view, and is provided with a downward opening groove 75 into which the upper end of the passive arm 42 is fitted.

  Although the upper end of the passive arm 42 is also formed in a substantially arc shape in a side view, an engagement step portion 76 is formed on the front side and a notch 77 is formed on the rear side. A head 42a with a neck is formed at the upper end of the head. The crown member 44 is formed with a claw portion 44a that fits into the engagement stage of the passive arm 42. For this reason, the crown member 44 is held on the passive arm 42 so that it cannot be detached without rattling.

  The pushing portion 43 of the backrest body 29 is formed in a pocket shape as described above, and the left and right side plates 43a, the top plate 43b connected to the upper ends of the left and right side plates, and the upper and lower sides connected to the inside of the left and right side plates 43a as a pair. And a longitudinal middle plate 43c. An inward front rib 43d is formed at the front end of the left right plate 43a, and the interval between the front ribs 43d is set to a dimension that allows the passive arm 42 to pass but the crown member 44 does not come out. The head 42a and the crown member 44 of the passive arm 42 are located between the front rib 43d and the middle plate 43c, and the passive arm 42 is pushed by the middle plate 43c via the crown member 44. The seat 2 moves forward in conjunction with the locking.

  The front surface of the intermediate plate 43c is a flat surface that extends straight in the left-right direction in plan view. For this reason, the crown member 44 can be pushed without being twisted. Since the middle plate 43c is provided in order to stably push the crown member 44 without being twisted, the space behind the middle plate 43c may be closed. That is, instead of providing the intermediate plate 43c, a stepped portion may be formed in the backrest body 29. As shown in FIG. 7, in the upper half of the middle plate 43c, there is no space behind and is substantially a stepped portion.

  As shown in FIG. 7, the backrest 3 rotates in the direction of the arrow 79 around the shaft center 78 of the upper support shaft 17, and by this rotation, the pushing portion 43 advances while descending. On the other hand, the support stay 40 only moves forward. Therefore, when the crown member 44 moves upward relative to the inside of the pushing portion 43 (by increasing the position of pushing the crown member 44 by the intermediate plate 43c), the forward movement of the seat 2 due to locking is permitted. Yes. When the body pressure acting on the backrest 3 is released, the support stay 40 is retracted by the spring 37, and then the pushing portion 43 is pushed by the crown member 44, and the backrest 3 returns and rotates.

  Now, a forward external force may be applied to the upper end of the backrest 3 in a state where the person is not leaning on the backrest 3, but in this embodiment, a front rib 43d is provided at the front end of the left and right side plates 43a of the pushing portion 43. As a result, even if an external force is applied to the backrest 3 in the neutral state, the front rib is prevented from leaning forward by the front rib hitting the crown member 44 from the front. Therefore, the forward tilt of the backrest 3 can be prevented without providing any special forward tilt prevention means. This is one of the advantages of this embodiment.

  Further, as shown in FIG. 8, since the rotation axis 27 of the movable base 4 and the axis 80 of the crown member 44 coincide with each other, the movable base 4 is accommodated in the pocket-shaped pushing portion 43. Nevertheless, the movable base 4 can be rotated without twisting.

  Further, when the movable base body 4 is lifted up, the backrest 3 loses the posture holding function. Therefore, if no special posture holding means is provided, the backrest 3 tilts backward due to its own weight, but the tilting is later pushed. 43 is prevented by hitting the crown member 44. Therefore, it is possible to prevent the backrest 3 from being tilted back to a state where the backrest 3 slides down without providing a special back tilt prevention means.

  It is also possible to provide the pushing portion 43 with a metal contact plate that hits the crown member 44 from behind. It is also possible to connect the passive arm 42 and the pushing portion 43 (the side plate 43a thereof) with left and right horizontally long pins without using a crown member (in this case, pin holes provided in the passive arm 42). Is allowed to be turned up and down by making the upper and lower longitudinal elongated holes).

(3). Backrest Connection Structure Next, the connection structure of the backrest body 29 to the upper support shaft 17 will be described mainly with reference to FIGS. As shown in FIGS. 9 and 10, the upper support shaft 17 protrudes to the left and right outside of the support frame 19 (rear foot 11), and includes a small-diameter portion 17 a protruding inward. And the bearing part 32 of the backrest main body 29 is fitted in the small diameter part 17a via the resin upper bush 82 so that rotation is possible. The upper bush 82 is made of a material having excellent strength and friction resistance, such as POM resin.

  Although the upper bush 82 is fitted to the bearing portion 32 from the outside, as shown in FIG. 9D, a left and right cylindrical portion 83 to which the upper bush 82 is fitted is integrated with the bearing portion 32 of the backrest body 29. On the other hand, the upper bush 82 is integrally provided with a stopper piece 82a that fits into the notch 83a of the cylindrical portion 83 and extends rearward. The upper bush 82 is held on the bearing portion 32 of the backrest main body 29 so as not to be relatively rotatable.

  As shown in FIG. 10, the upper bush 82 has an end plate 82 b that overlaps the end surface of the small-diameter portion 17 a of the upper support shaft 17, and the middle plate 32 a of the bearing portion 32 and the upper bush 82 are The support shaft 17 is held so as not to be detached. A collar 84 with a flange is fitted to the upper screw 18, and the bearing portion 32 and the upper bush 82 are firmly fastened by holding the tip of the collar 84 at the bottom of a restriction hole provided in the upper support shaft 17. It is held in a rotatable state without any problems.

  A recess 32c for concealing the head of the upper screw 18 is formed in the bearing portion 32 of the backrest body 29 so as to open to the left and right inner sides and the front, and a sliding upper cap 33 is fitted in the recess 32c. Yes. An end cap 85 is fitted on the outer end surface of the upper support shaft 17. The upper support shaft 17 is used for mounting an armrest. The hole in which the end cap 85 is fitted is a female screw hole used for attaching an armrest.

As clearly shown in FIG. 10, the portion of the bearing portion 32 of the backrest body 29 where the stopper piece 82 a of the upper bush 82 overlaps has an inclined surface 32 b that is shifted inward to the left and right. The rear end of the inclined surface 32b is located substantially directly behind the inner end surface of the upper bush 82, and the inclined portion 32b of the bearing portion 32 is behind the inclined surface 32b and has a larger arc angle than the inclined surface 32b. The part 86 is continuous.

  Further, in the upper bush 82, the base of the stopper piece 82a is slightly shifted outward from the end plate 82b. Therefore, a step 82c is formed between the end plate 82b and the stopper piece 82a. The rear part of the bearing part 32 is fitted in 82c. The upper bush 82 is fitted to the bearing portion 32 over the entire circumference at the step 82c. For this reason, a high axial support function is exhibited and the upper bushing 82 is securely and firmly fitted to the bearing portion 32.

  As described above, the pushing portion 43 of the backrest main body 29 is fitted in the crown member 44 of the support stay 40. Therefore, when assembling the chair, the backrest main body 29 must be fitted into the upper support shaft 17 while the pushing portion 43 is fitted into the movable base 4. In this respect, in this embodiment, as shown in FIGS. 11 and 12, the backrest body 29 is once inclined forward from the neutral position (reference position), and the backrest body 29 is fitted into the crown member 44, and then the crown The bearing portion 32 can be fitted into the upper support shaft 17 by raising the member 44 as a fulcrum and moving it backward.

  That is, the notch 83a of the bearing portion 32 is opened rearward, while the pusher portion 43 is substantially long in the vertical direction. For this reason, the backrest is simply moved backward or moved downward. Then, although the fitting of the bearing portion 32 to the upper support shaft 17 and the fitting of the pushing portion 43 to the crown member 44 cannot be performed simultaneously, the upper support shaft 17 is inclined by tilting the backrest 3 forward with respect to the reference posture. The fitting of the bearing portion 32 into the shaft and the fitting of the pushing portion 43 into the crown member 44 can be performed in a series.

  In this assembly, the upper bush 82 is fitted into the upper support shaft 17 first. The rear portion of the upper bush 82 and the rear end of the bearing portion 32 are engaged in the left-right direction by the dimension E of the step 82c, but the backrest body 29 is slightly elastically deformed so that the interval between the left and right bearing portions 32 is reduced. Therefore, by pressing the inclined surface 32b against the front end of the upper bush 82 and pushing backward, the inclined surface 32b moves over the upper bush 82 and moves backward, and at the same time, the bearing portion 32 and the upper bush 82 are firmly fixed. Fit together.

Thus, enabling the mounting of the backrest body 29 (the seat back 3) very easily and reliably. The backrest main body 29 is roughly determined in the left and right positions by the crown member 44. However, if the inclined portion 86 is formed behind the bearing portion 32 as in the embodiment, it is preferable because the guiding function is improved.

  In the above embodiment, the bearing portion is provided on the backrest (backrest main body) and the upper support shaft is provided on the support frame. However, the support shaft can be provided on the backrest and the bearing portion can be provided on the support frame.

  The present invention can be manufactured as a chair. Therefore, it can be used industrially.

DESCRIPTION OF SYMBOLS 1 Leg apparatus 2 Seat 3 Backrest 4 Movable base body 11 Rear foot 17 Upper support shaft 19 Support frame (leg support) as an example of a support member
DESCRIPTION OF SYMBOLS 21 Main body part of movable base body 22 Square arm of movable base body 23 Boss part of square arm 24 Lower support shaft 29 Backrest main body 32 Bearing part of backrest 36 Slider constituting seat receiving body 37 Spring 40 Constructing seat receiving body Support stay 42 Passive arm 43 Pushing portion 43c Middle plate 43d Front rib 44 Crown member constituting passive portion

Claims (4)

A support frame disposed on the left and right outside of the seat; and a backrest attached to the support frame at a height higher than the seat surface, the backrest comprising a support shaft and a bearing having a horizontal axis. It is connected to the support frame by a pair with a portion, a support shaft is provided on one of the backrest and the support frame, and a bearing portion is provided on the other,
The bearing is provided with a notch that fits into the support shaft by moving the backrest from the front to the back.
Chair. The backrest is tiltable rearwardly, and a resin bush is interposed between the support shaft and the bearing so that the backrest is attached with the bush mounted on the support shaft in advance. The bearing and the support shaft are held in a non-detachable manner by screws,
The chair according to claim 1. The bush is provided with an outward stopper piece that fits into the notch of the bearing, and when the stopper piece fits into the notch , the bush is held so as not to rotate relative to the bearing. ,
The chair according to claim 2. The backrest is tiltable rearward and the seat is movable back and forth, and an upward passive arm is provided at the rear end of the seat or a seat receiving body that is movable back and forth, and the lower end of the backrest. Is formed with a pocket-shaped pushing portion that is fitted to the passive arm from above, and when the backrest tilts backward, the passive arm is pushed by the pushing portion and the seat moves forward. And the backrest is moved backward in a state where the backrest is tilted forward with respect to a reference posture on which a person is not leaning, so that the fitting of the bearing portion and the support shaft and the pushing portion with respect to the passive arm The mating is performed in a series,
The chair as described in any one of Claims 1-3.

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