JP3345342B2 - Chair locking equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chair locking device for supporting a backrest in a tiltable manner. More specifically, the present invention relates to a chair locking device capable of changing a mounting position of a backrest only by exchanging some parts at the time of manufacturing.

[0002]

2. Description of the Related Art A chair often employs a locking mechanism for supporting a backrest in a tiltable manner in accordance with the posture of a seated person. The locking device includes a main frame attached to an upper end of a leg portion, a backrest support member for a backrest swingably attached to the mainframe, and a backrest support member interposed between the backrest support member and the mainframe. At least a reaction force generation mechanism is provided, and the reaction force generation mechanism applies a reaction force to the movement of the backrest to prevent the backrest from tilting vigorously when the occupant leans, and the backrest returns to the basic posture I am trying to do it. As a locking device, there is a synchro locking device of a type in which a backrest and a seat are interlocked and tilted.

On the other hand, today, chairs of various designs are produced, and the mounting position of the backrest with respect to the locking mechanism, that is, the position and the mounting direction of the backrest supporting member are changed according to the design of the backrest. I have. For example, a case in which the backrest support member is routed from the center of the backrest and connected to the reaction force generating mechanism from the rear of the main frame, and a backrest support member is routed from the left and right sides of the backrest to react from the left and right sides of the main frame. When manufacturing a chair with a case connected to the generating mechanism, two types of locking devices are separately prepared: a type in which the backrest support member is connected from the rear and a type in which the backrest support member is connected from both the left and right sides. Is used properly.

[0004]

However, if different types of locking devices were prepared separately, a large variety of products would be produced in small quantities, resulting in an increase in parts manufacturing / assembly costs and inventory management costs. I will. On the other hand, if a common locking device is used, there is a problem that the design of the chair is restricted because the way of arranging the backrest supporting member is limited.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a chair locking device capable of changing a connecting position of a backrest support member by replacing only a part of components. That is, an object of the present invention is to provide a locking device for a chair in which most of the locking mechanism is shared and a backrest having a completely different design can be adopted.

[0006]

In order to achieve the above object, according to the present invention, a main frame attached to an upper end of a leg and a backrest of a backrest pivotally attached to the main frame are provided. A locking device comprising at least a backrest support member and a reaction force generating mechanism interposed between the backrest support member and the main frame to generate a reaction force for returning the backrest to the basic posture. A support shaft rotatably connected to the frame, a lever having a lever for transmitting the rotation of the support shaft to the reaction force generating mechanism, and a bearing portion rotatably supporting the support shaft so as to be able to penetrate outside the main frame; A hole is provided in the main frame to expose the support shaft in the main frame toward the rear, and the hole is attached to the support shaft portion in the main frame through the hole or the bearing Is a selectively attachable to the backrest carrier at both ends of the support shaft protruding outside the mainframe.

[0007] Therefore, it is possible to mount a backrest having a completely different design on a common synchro locking mechanism only by changing the manner of handling the backrest support member. That is, a backrest support member is attached to a support shaft portion in the mainframe through a hole in the mainframe, and the tip of the backrest support member is connected to a reaction force generating mechanism to attach the backrest support member to the rear of the main frame. It becomes possible to manufacture a chair, and by fitting backrest support members to both ends protruding out of the mainframe from the bearing portion of the support shaft connected to the reaction force generating mechanism via a lever, the backrest support member can be manufactured. It is possible to manufacture a chair of a type in which backrest support members are attached to the left and right. As described above, since one synchro-locking device can be used for a chair in which the mounting position of the backrest supporting member is different, it is possible to use common components and reduce the production cost, and it is possible to reduce the design cost. It can flexibly respond to diversification requests.

According to a second aspect of the present invention, in the locking device for a chair according to the first aspect, the lever comprises a swinging member which is attached to the support shaft and projects from a hole behind the main frame. The backrest support member is connected to the rear end of the member, and the reaction force generating mechanism is rotatably connected to the front end. In this case, when the seated person leans against the backrest and the backrest support member is tilted from the basic posture, the swinging member swings about the support shaft by an angle corresponding to the tilt angle to compress the reaction force generating mechanism, thereby supporting the backrest. A reaction force for returning the member is generated. Since the swinging member to which the backrest support member is connected protrudes rearward of the frame, the backrest support member is connected to the reaction force generating mechanism from behind the frame.

According to a third aspect of the present invention, in the chair locking device according to the second aspect, the rear portion of the seat portion of the chair is connected to the swinging member, and the front portion is rotatable and movable back and forth. To be connected. Therefore, the seat is supported by the main frame and the swinging member, and the seat is also inclined with the tilt of the backrest supporting member.

According to a fourth aspect of the present invention, in the locking device for a chair according to the first aspect, the backrest support member is non-rotatably connected to both ends of the support shaft projecting out of the main frame from the bearing portion. The lever is non-rotatably connected to the support shaft, and the end thereof is rotatably connected to the reaction force generating mechanism. Therefore, when the seated person leans on the backrest and the backrest support member is tilted from the basic posture, the support shaft rotates by an angle corresponding to the tilt angle, the coaxial lever also rotates by the same angle, and compresses the reaction force generating mechanism. A reaction force for returning the backrest member is generated. Since the support shaft to which the back support member is connected protrudes to the left and right sides of the frame, the back support member is connected to the reaction force generating mechanism from both the left and right sides of the frame.

According to a fifth aspect of the present invention, in the chair locking device of the fourth aspect, a seat support member is non-rotatably connected to both ends of the support shaft protruding from the main frame, and a tip end of the seat support member is seated on the chair. The front part of the seat is connected to the frame so as to rotate and move back and forth freely. In this case, the seat portion is supported by the frame and the seat support member, and the backrest support member and the seat support member, which are coaxial via the support shaft, rotate interlockingly, so that the seat portion also interlocks with the inclination of the backrest support member. Incline.

Here, in the locking device for a chair according to any one of claims 1 to 5, the support shaft is a square bar, and a portion supported by the bearing portion of the main frame has a square hole on the inner surface and an outer surface on the outer surface. Preferably, a circular sleeve is fitted. In this case, by simply fitting the backrest support member or the lever on the support shaft, these can be connected to the main frame so as to be relatively non-rotatable.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below in detail based on the best mode shown in the drawings.

FIGS. 1 to 4 show an embodiment of a chair locking device according to the present invention. The locking device 1 of this embodiment includes a main frame 4 attached to the upper end of the leg 2, a seat plate 3 for a seat and a backrest support member 6 for a backrest that are swingably attached to the main frame 4,
A reaction force generating mechanism 5 interposed between the backrest support member 6 and the main frame 4 to generate a reaction force for returning the backrest to the basic posture;
In addition, the rear plate is attached to a backrest support member 6 which is tiltably connected to the main frame 4 so that the seat plate can move in the front-rear direction in accordance with the tilt of the backrest support member 6. It is comprised including. In the present embodiment, a synchro-locking mechanism that synchronizes not only the swing of the backrest but also the swing of the seat is provided. However, the present invention is not particularly limited thereto. It can also be configured as a locking device including a force generating mechanism.

The main frame 4 is fixed to the top of the leg portion 2 to support the seat and the backrest. In the case of the present embodiment, the floor side is opened by the upper plate 4a and the side plates 4b, 4c. It is made of a grooved die-cast molded product, and accommodates therein the reaction force generating mechanism 5, the backrest support member 6, the reaction force adjusting mechanism 19, and the like. On both sides of the rear portion of the main frame 4, bearing portions 4 d and 4 e for rotatably supporting the support shaft 10 so as to penetrate outside the main frame 4 are formed, and the backrest support member 6 is rotated by the main frame 4. A support shaft 10 is provided for freely connecting. A hole 8 for exposing the support shaft 10 in the main frame 4 rearward is formed in the upper plate 4a at the rear part of the main frame 4,
The backrest supporting member 6 is provided so that it can be taken out rearward through the hole 8. The backrest support member 6 is attached to the support shaft 10 in the main frame 4 through the hole 8. The support shaft 10 is formed of a round bar in the present embodiment, but is not particularly limited to this. The square shaft and the sleeve 27 are combined like the support shaft 25 of the embodiment of FIGS. 5 to 7. May be used.

Most of the backrest supporting member 6 is formed of a round bar, but the front side of the backrest supporting member 6 is formed of a plate-like frame so as to be easily inserted into the main frame 4 and attached thereto. The separate swing member 9 is fixed by welding or the like. The swing member 9 corresponds to a lever connecting the support shaft 10 and the reaction force generating mechanism 5 to the main frame 4 by the support shaft 10 rotatably supported by bearings 4d and 4e of the main frame 4. It is swingably mounted, and its tip (front end) is detachably connected to the connection shaft 11 of the reaction force generating mechanism 5. Therefore, the backrest support member 6 swings around the support shaft 10 or together with the support shaft 10 and at the same time, causes the reaction force generating mechanism 5 to store elastic force. Both ends of the support shaft 10 are rotatably supported by bearings 4 d and 4 e formed on the side plates 4 b and 4 c of the main frame 4. In some cases, the swing member 9 is fixedly supported and the swinging member 9 is attached to the support shaft 10. It may be provided so as to rotate with respect to it. The outer openings of the bearings 4d, 4e are closed by covers 12, 12.

The reaction force generating mechanism 5 is interposed between the backrest support member 6 and the main frame 4 to move the backrest in the basic posture P.
And generates a reaction force for returning the backrest support member 6 inclined from the basic posture P shown in FIG. 4 to the basic posture P. For example, a pair of left and right spring units 14 and Are connected and synchronized. Each spring unit 14 is a telescopic link having a coil spring 15. In the case of the present embodiment, the coil spring 1
Spring mounts 16 and 1 attached to both ends of 5
An extensible link is formed by the guide shaft 7 which connects the spring mounts 16 and 17 so as to be movable only in the axial direction. The front spring mount 16 of each spring unit 14 is attached to the main frame 4, and the rear spring mount 17 is attached to the connection shaft 11.
Are rotatably connected to a swinging member 9 which forms a part of the backrest supporting member 6 through the base member. Further, a reaction force adjusting mechanism 19 for changing the precompression amount (initial pressure) of the coil spring 15 is interposed between the front spring mount 16 of the one spring unit 14 and the main frame 4. As shown in detail in FIG. 8, the reaction force adjusting mechanism 19 allows a wedge-shaped piece member 41 to freely enter and exit between a bracket 42 on the main frame 4 side and an attachment 44 connected to the spring mount 16 by a screw rod 43. The attachment 44 and the front spring mount 1 are provided by rotating the screw rod 43 by adjusting the grip 20.
The pre-compression amount of the coil spring 15 is changed by moving the position 6 back and forth. The attachment 44 is normally urged by a spring force in a direction in which the wedge-shaped piece member 41 is pushed out, that is, a direction in which a space between the mounts 16 and 17 is increased. Note that the basic posture P refers to a posture in which the backrest support member is most raised when the chair is free and not in use.

In this embodiment, the reaction force generating mechanism 5
A gas damper 13 for fixing the backrest at an arbitrary position / inclination is incorporated therein. The gas damper 13 is a gas spring that closes the flow path of the filling gas by operating a lever, locks its length (a rod that moves in and out), and fixes the backrest support member 6.
The rod tip is connected to the connecting shaft 11 so as to be relatively rotatable.
At the tip of the gas damper 13, a lever 22 for operating a valve for closing a flow path of the filling gas is attached.
The lever 22 is operated by an operation lever 23 provided on a side of the outer shell 3.

Here, the connection between the seat frame (hereinafter referred to as the outer shell including the seat plate) 3 constituted by the outer shell and the main frame 4 can be performed by either the front portion of the outer shell 3 or the main frame 4. One of the members is provided with a front shaft portion 24 extending in the width direction of the chair, and the other member is formed with a front locking portion 32 for locking the peripheral surface of the front shaft portion 24, and the rear portion and the backrest of the outer shell 3 are formed. One of the support members 6 is provided with a rear shaft portion 29 extending in the width direction of the chair, and the other member is formed with a rear locking portion 33 for locking the peripheral surface of the rear shaft portion 29. At least one of the rear shaft portion 24 and the rear shaft portion 29 is movable in the front-rear direction of the outer shell 3 in accordance with the tilt of the backrest support member 6.
In the present embodiment, claw-shaped locking portions 32 and 33 are formed before and after the outer shell 3, and shaft portions 24 and 29 made of a shaft are provided on the front and backrest support members 6 of the main frame 4. The front shaft portion 24 is provided movably in the front-rear direction with respect to the main frame 4.

The outer shell 3 is a synthetic resin molded product and has sufficient rigidity as a seat plate of a chair by appropriately forming ribs and the like. A front locking portion 32 and a rear locking portion 33 are formed integrally with the outer shell 3. Each of the locking portions 32 and 33 has, for example, a hook shape as shown in FIG. 1, and is formed two at each of two front left and right portions and two rear right and left portions of the outer shell 3. A through hole 36 is formed in the outer shell at the projection surface position corresponding to at least the undercut portion (claw portion) of the front locking portion 32 and the rear locking portion 33. The formation of the through hole 36 eliminates the formation of an undercut portion in the injection mold, so that the hook-shaped front and rear locking portions are simple split molds without using complicated molds such as slide molds and cam molds. 3
2, 33 can be made moldable. In addition, outer shell 3
Is formed with a retaining wall 3a so as to sandwich the front locking portion 32 and the rear locking portion 33. Each retaining wall 3a is attached to each of the locking portions 32, 33 by shafts 24, 29 which are front and rear shaft portions.
When they are fitted, they face both end surfaces of the shafts 24 and 29 to prevent them from falling off in the axial direction. Note that tapered ribs are formed inside the locking portions 32 and 33, and shafts 24 and
29 is prevented from coming off by fitting. In addition, a cushion 38 is attached on the outer shell 3,
Furthermore, a seat is constituted by covering it with a covering material.

The main frame 4 has a mounting hole 4f formed in the rear boss thereof for inserting the upper end of the leg 2 into the mounting hole 4f. 2 so as to be attachable. Also, in front of both side plates 4b and 4c of the main frame 4,
Slender guide holes 4g are formed in the front-rear direction of the outer shell 3, respectively, and a slide shaft (hereinafter, referred to as a slide shaft 24) as the front shaft portion 24 passes through each of the guide holes 4g. Therefore, the slide shaft 24 is movable in the front-rear direction of the outer shell 3 within a range where each guide hole 4g is formed. The front of the outer shell 3 is connected to the main frame 4 by fitting the slide shaft 24 into the hook-shaped front locking portion 32 from the radial direction. A sleeve 31 made of a sliding material is fitted into each guide hole 4g.

On the other hand, a synchro shaft (hereinafter, referred to as a synchro shaft 29) constituting the rear shaft portion 29 is fixed to the backrest support member 6 so as to penetrate the backrest support member 6 in the width direction of the chair. And this synchro shaft 29
Is fitted into the hook-shaped rear locking portion 33 from the radial direction, so that the rear of the outer shell 3 is connected to the backrest support member 6. Each of the shafts 24 and 29 is a simple round bar having no locking means such as a rivet head or a screw at the end.

According to the synchro-rocking device having such a configuration, when the occupant leans on the backrest, the backrest support member 6 is inclined rearward about the support shaft 10. Thereby, the tip of the backrest supporting member 6 compresses the gas damper 13 of the reaction force generating mechanism 5 and each spring unit 14. Coil spring 15 of each spring unit 14
Is compressed, a reaction force for returning the backrest support member 6 to the basic posture P is generated. Further, in conjunction with the inclination of the backrest support member 6, the outer shell 3 also inclines so as to sink backward while moving the slide shaft 24.

Further, when the occupant locks the gas damper 13 by locking the operation lever 23 in a state where the backrest support member 6 is inclined to an arbitrary angle, the backrest support member 6
Is fixed at that position, and the posture of the backrest and the outer shell 3 is kept constant. From this state, when the occupant releases the operation lever 23 to allow the gas damper 13 to expand and contract, the lock of the backrest support member 6 is released and the reaction force of each spring unit 14 is caused by the occupant's rising motion. The backrest supporting member 6 returns to the basic posture P. That is, the posture of the backrest and the outer shell 3 is returned to the original position.

Further, by attaching the front of the outer shell 3 to the main frame 4 and attaching the rear to the backrest support member 6, the outer shell 3 can be attached without using the conventionally required seat bracket. In addition, the central portion of the outer shell 3 floats away from the main frame 4 so that the central portion of the outer shell 3 does not directly hit the main frame 4 and exerts its elasticity even when seated vigorously. Because it can be done, the occupant does not feel unpleasant bottom feeling.

Next, FIGS. 5 to 7 show another embodiment of the synchro locking device of the present invention. This embodiment is
The backrest support member 6 is arranged from the side of the main frame 4. In the present embodiment,
Although the way of maneuvering the backrest support member 6 and the support mechanism behind the seat plate 3 are different, the other elements are common and will not be described in detail. The hole 8 formed in the main frame 4 is closed by a cover 30.

In the locking device 1 of this embodiment, the front of the seat plate 3 and the main frame 4 are connected so as to be able to swing and move back and forth, and the rear of the seat plate 3 and the seat plate supporting member 28 are swinging. Connected to the backrest support member 6
The back support member 6 rotates in synchronism with the back support member 6 in accordance with the tilting of the back support member 28 to thereby move the seat plate 3 in the front-rear direction and slightly raise and lower the seat plate 3.

The seat plate support member 28 is connected to the back support member 6 via a support shaft 25, and rotates synchronously with the back support member 6. The support shaft 25 is incorporated in bearings 4 d and 4 e of the main frame 4 via a sleeve 27 having a circular outer peripheral surface, and is rotatably supported by the main frame 4. The inner peripheral surface of the sleeve 27 has a square hole similar to the angular cross-sectional shape of the support shaft 25, and rotates with the support shaft 25. Also,
The bearing portion 4d of the main frame 4 of the sleeve 27,
The outer shape of the end protruding from 4e forms a non-circular shape, for example, a square shape like the support shaft 25, and the seat support member 28 fitted to the end can be supported so as to rotate together with the support shaft 25. I have.

The backrest support member 6 is routed from both left and right sides of the backrest, and is bent inward in a substantially L-shape so that the lower ends thereof face each other. Are formed. Backrest support member 6
Are fitted to the protruding portions 25a at both ends of a support shaft 25 which is rotatably supported by penetrating the main frame 4 in the width direction and is connected non-rotatably.

The support shaft 25 has a non-circular shape, for example, a square shape, and the projections 25a at both ends thereof are projected from the left and right bearings 4d and 4e of the main frame 4, so that the backrest support member 6 is formed.
Are press-fitted. A lever 26 is connected to the center of the support shaft 25 so as to be relatively non-rotatable, and is provided to swing the lever 26 in conjunction with the backrest support member 6. The reaction force generating mechanism 5 is connected to the tip of the lever 26.

That is, as described later, the backrest supporting member 6
And the part to which the lever 26 is connected,
It is shaped into a square bar. The support shaft 25 penetrates through the bearings 4d and 4e of the main frame 4 and has both ends protruding left and right. The square holes 6a of the backrest support member 6 are fitted into the respective protruding portions 25a, and the support shaft 25 and the backrest support member 6 are connected to each other so that they cannot rotate relative to each other.

The support shaft 25 and each of the bearings 4d, 4e
Sleeves 27 are fitted between the two.
The hole of each sleeve 27 has a square hole shape, and the support shaft 2
5 cannot rotate. In addition, each sleeve 2
The outer peripheral surface of 7 is formed in a circular shape at a portion inside the portion including the portions fitted into the bearing portions 4d and 4e, and is rotatable with respect to the bearing portions 4d and 4e, that is, the main frame 4. On the other hand, a portion of the outer peripheral surface of each sleeve 27 outside a portion fitted into the bearings 4d and 4e is formed in a square bar shape, and the seat support member 28 is fitted into the square bar portion so as to be relatively non-rotatable. Have been. That is, the seat support member 28 is connected to the support shaft 25 with the respective sleeves 27 interposed therebetween. Since the seat support member 28 and the sleeve 27 and the connection portion between the sleeve 27 and the support shaft 25 form a square rod shape. , Each seat support member 28 is a support shaft 2
5 cannot rotate.

A synchro shaft 29 is attached to the tip of each seat support member 28, and the synchro shaft 29 is fitted into a rear locking portion 33 of the seat plate (or a seat frame fixed thereto). Therefore, the weight of the occupant directly acts on each seat support member 28, but since the sleeve 27 in which each seat support member 28 is fitted is formed thicker than the support shaft 25, the seat plate 3 has a large rigidity. Can support. The synchro shaft 29 is connected to the backrest support member 6 though the seat support members 28, the sleeves 27, and the support shafts 25 are interposed therebetween.
Is attached to the backrest supporting member 6. In the present embodiment, each shaft 24,
Although the thing provided with the hole seat frame which has the hole which penetrates 29 is employ | adopted, it does not specifically limit to this and the seat plate 3 may be used also as an outer shell.

Two levers 26 are provided corresponding to the pair of spring units 14 of the reaction force generating mechanism 5. Each lever 26 is formed integrally with each sleeve 27, and has a bifurcated tip connected to the support shaft 11 of the reaction force generating mechanism 5.

According to the synchro-rocking device having such a configuration, when the occupant leans on the backrest, the backrest support member 6 tilts backward while rotating the support shaft 25 and the sleeve 27. Thereby, the lever 26 is connected to the gas damper 13 of the reaction force generating mechanism 5 and each spring unit 14.
Press down. When the coil spring 15 of each spring unit 14 is compressed and contracted, a reaction force for returning the backrest support member 6 to the basic posture P is generated. Further, since each seat support member 28 is also rotated by the rotation of each sleeve 27, the seat plate 3 is interlocked with the inclination of the backrest support member 6.
Also, the slide shaft 24 is inclined so as to sink backward while moving the slide shaft 24 in the guide hole 4g in the front-back direction.

When the occupant locks the gas damper 13 by locking the operation lever 23 with the backrest support member 6 inclined to an arbitrary angle, the sleeves 27 and the support shaft 25 cannot rotate. The backrest support member 6 is locked. Therefore, the postures of the backrest and the seat plate 3 are kept constant. From this state, when the occupant releases the operation lever 23 to allow the gas damper 13 to expand and contract, the lock of the backrest support member 6 is released and the reaction force of each spring unit 14 is caused by the occupant's rising motion. The backrest supporting member 6 returns to the basic posture P. That is, the postures of the backrest and the seat plate 3 can be returned to the original positions.

In the above-described locking device 1 of the present invention, it is possible to mount a backrest having a completely different design on a common locking mechanism only by changing the manner of handling the backrest support member 6. That is, when manufacturing a chair of a type in which the backrest support member 6 is attached to the rear of the main frame 4, the backrest support member 6 is swung by the support shaft 10 on the main frame 4 in which the reaction force generating mechanism 5 is assembled. What is necessary is just to connect movably and to connect the tip of the backrest support member 6 to the connection shaft 11 of the reaction force generating mechanism 5.
When manufacturing a chair of a type in which the backrest support member 6 is attached to the left and right sides of the main frame 4, the support shaft 2 is attached to the main frame 4 in which the reaction force generating mechanism 5 is assembled.
5 and the respective sleeves 27, the tip of the lever 26 is connected to the connecting shaft 11,
After the seat support member 28 has been fitted into the seat 7, the left and right backrest support members 6 may be fitted.

As described above, since one synchro-rocking device 1 can be used for a chair in which the mounting position of the backrest supporting member 6 is different, it is possible to use common parts and to reduce the production cost. It is possible to respond flexibly to the demand for diversification of design.

The above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the gist of the present invention. For example, in the above description, the tip portion of the back support member 6 is the swing member 9, but the swing member 9 is not necessarily integrated, and the swing member 9 supported by the support shaft 10 is connected to the back support member 6. Separately, and the back support member 6 may be connected to the rear end of the swing member 9.

In the above description, the reaction force adjusting mechanism 19 is interposed between the one spring unit 14 of the reaction force generating mechanism 5 and the main frame 4, but the reaction force adjusting mechanism 19 is not always necessary. Needless to say, this may be omitted.

Further, in the embodiment shown in FIGS. 1 to 4, the support shaft 10 composed of a round bar is employed, but the present invention is not particularly limited thereto, and the support shaft composed of a square bar as in the embodiment of FIG. 25 and a sleeve 27 may be employed. Also, FIG.
In the embodiment of FIG. 7, a support shaft made of a round bar may be adopted.

[0042]

As described above, in the chair locking apparatus according to the first aspect, the connection position of the backrest support member is changed only by changing the connection mechanism while sharing the elements of the locking mechanism, that is, the main frame and the reaction force generating mechanism. Therefore, it is possible to mount a backrest having a completely different design on a common locking mechanism simply by changing the way the backrest support member is handled.
Therefore, design restrictions can be reduced while reducing costs by sharing parts.

In the case of the second aspect of the present invention, since the swinging member to which the backrest support member is connected protrudes rearward of the frame, it is possible to design a chair in which the backrest support member is arranged at the center of the backrest. Becomes

According to the third aspect of the present invention, the seat is supported by the main frame and the swinging member, and the seat can be inclined with the tilt of the backrest supporting member.

According to the fourth aspect of the present invention, since the back support member is connected to the support shaft projecting from the left and right sides of the main frame, the chair in which the back support member is disposed on the left and right sides of the backrest. Design is possible.

Further, in the case of the invention described in claim 5, the seat portion supported by the main frame and the seat support member rotates interlockingly with the back support member via the support shaft, and thus interlocks with the inclination of the back support member. The seat can also be inclined.

Further, in the case of the invention according to claim 6, since the backrest supporting member and the lever can be connected to the main frame in a non-rotatable manner only by fitting the backrest supporting member and the lever on the supporting shaft, the assembly is easy. Productivity can be further improved.

[Brief description of the drawings]

FIG. 1 is a view showing one embodiment of a chair locking device according to the present invention, and is a perspective view of a state in which a locking device is attached to a seat as viewed from a bottom surface.

FIG. 2 is a bottom view of the locking device of FIG. 1;

FIG. 3 is an enlarged perspective view showing a main frame and a backrest supporting member of the locking device of FIG. 1;

FIG. 4 is a schematic configuration diagram of a state where the locking device of FIG. 1 is attached to a seat.

FIG. 5 is a bottom view showing another embodiment of the chair locking device according to the present invention.

FIG. 6 is an enlarged perspective view showing a locking device main frame and a backrest support member of FIG. 5;

7 is a schematic configuration diagram of a state where the locking device of FIG. 5 is attached to a seat.

FIG. 8 is a sectional view showing a reaction force adjusting mechanism of the locking device of the present invention in detail.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Locking device 2 Leg part 4 Main frame 5 Reaction force generating mechanism 6 Back support member 9 Swing member (corresponding to a lever) 10, 25 Support shaft 25a Projection of support shaft (of support shaft protruding outside from the main frame) Both ends) 26 Lever P Basic posture of back support member

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-7-155238 (JP, A) JP-A-8-70952 (JP, A) JP-A-9-238768 (JP, A) JP-A-10- 57176 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) A47C 3/026 A47C 3/027

Claims (6)

(57) [Claims] 1. A main frame attached to an upper end of a leg, a backrest supporting member of a backrest slidably mounted on the mainframe, and an intervening member between the backrest supporting member and the main frame. A rocking device having at least a reaction force generating mechanism for generating a reaction force for returning the backrest to the basic posture, a support shaft rotatably connecting the backrest support member to the main frame, and a support shaft; A lever for transmitting the rotation of the support shaft to the reaction force generating mechanism, and a bearing portion for rotatably supporting the support shaft so as to be able to penetrate out of the main frame, and moving the support shaft in the main frame backward. The main frame is provided with a hole to be exposed toward the main frame, and the hole is attached to a support shaft portion in the main frame through the hole, or a hole is provided from the bearing portion. A rocking device for a chair, wherein the backrest support member can be selectively attached to both ends of the support shaft protruding outside the in-frame. 2. The lever comprises a swing member attached to the support shaft and projecting from the hole behind the main frame, and the backrest support member is connected to a rear end of the swing member. 2. The chair locking device according to claim 1, wherein the reaction force generating mechanism is rotatably connected to a front end. 3. The locking device for a chair according to claim 2, wherein a rear portion of the seat portion of the chair is connected to the swinging member, and a front portion is connected to the frame so as to rotate and move back and forth. 4. The backrest supporting member is non-rotatably connected to both ends of the support shaft projecting out of the main frame from the bearing portion, and the lever is non-rotatably connected to the support shaft. 2. The chair locking device according to claim 1, wherein a tip is rotatably connected to the reaction force generating mechanism. 5. A seat support member is non-rotatably connected to both ends of the support shaft protruding from the main arm, and a tip of the seat support member is connected to a rear portion of a chair seat, and a front portion of the seat is connected to the frame. The locking device for a chair according to claim 4, wherein the connecting device is rotatable and movable back and forth. 6. The support shaft is a square bar, and a sleeve whose inner surface is a square hole and whose outer surface is circular is fitted in a portion supported by a bearing portion of the main frame. 6. The chair locking device according to any one of 1 to 5.