JP3506901B2 - Chair synchro locking device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synchro locking device in which a seat and a backrest of a chair are interlocked and tilted. More specifically, the present invention relates to an improvement in a synchro locking mechanism, particularly a mounting structure for a seat plate.

[0002]

2. Description of the Related Art A conventional synchro locking device for a chair is constructed independently as a mechanism and is assembled regardless of a seat or a backrest. The seat and backrest are separately attached to the seat bracket and the backrest support member, and their movements are interlocked via the synchronizing means. That is, in a conventional sync locking device, for example, a main frame attached to the upper ends of the legs, a seat bracket that swingably attaches to the main claim, supports a seat plate portion of the seat, and a backrest that supports a backrest. Support member (also called back support rod)
And a synchro means such as a link for connecting and interlocking the backrest support member and the seat support fitting, and interposed between the backrest support member and the main frame or between the seat support fitting and the main frame. And a reaction force generation mechanism that generates a force to return to the basic posture when the backrest is tilted. Here, the seat bracket has its front end side rotatably directly connected to the front end of the main frame and its rear end side supported by the main frame via a link or the like.
It is swingably supported so that it can be opened and closed like scissors around the connecting point at the front end. The seat bracket and the main frame are connected to each other, for example, by using a rivet head shaft and a push nut having a saw-toothed flange for preventing slippage that is deformed when fitted to the shaft. And
The seat is supported by screwing the seat plate to the seat bracket. The seat bracket fitted on the seat plate also functions as a reinforcing member for the seat plate.

[0003]

However, the conventional locking mechanism has a structure in which a seat bracket made of an iron plate is superposed on the central portion of the seat plate so that they are in close contact with each other. There is a feeling of bottoming out. Further, the presence of the seat bracket causes an increase in the number of component parts and the mounting process by itself, and it also takes time and effort to fix the seat plate to the seat bracket by a screw or the like. It is one. Moreover, the seat bracket is not an indispensable element in the synchro locking mechanism, and can be omitted if the seat plate itself has sufficient rigidity and no reinforcement is required.

SUMMARY OF THE INVENTION An object of the present invention is to provide a chair locking mechanism for a chair, which does not require a seat bracket and which is excellent in productivity and which provides good sitting comfort.

[0005]

In order to achieve the above object, the invention according to claim 1 is a synchro locking device which is attached to the upper ends of legs and supports a seat and a backrest so as to be tiltable in association with each other. A main frame attached to the upper ends of the legs, a seat plate of a seat that is attached to the main frame so as to be swingable, and a backrest support member for a backrest, and an interposition between the backrest support member and the main frame. A reaction force generating mechanism for generating a reaction force for returning the backrest to the basic posture, and a front support of the seat plate, a main frame, a rear support of the seat plate and a back support member or a seat support that rotates in synchronization with the back support member. While swingably connecting to the member,
Walking seat plate and the main frame is movable in the longitudinal direction of the seat plate according to the tilt of the backrest carrier to the seat plate backrest carrier at least one of the coupling of the support member,
Also, float the center part of the seat plate away from the main frame.
It is supported in the state where it is supported, and the synchro locking mechanism is configured including the seat plate.

Therefore, the front and rear sides of the seat plate are supported by the main frame and the backrest support member or the seatback support member that rotates in synchronization with the backrest support member, and are supported so as to interlock with the movement of the backrest support member. Therefore, when the seated person leans against the backrest, the rear part of the seatboard is pulled backward and downward with the tilting of the backrest support member, and the seatboard also tilts in conjunction with the backrest. Also, the front and rear of the seat plate are attached to the main frame and the backrest support member, and since the center part of the seat plate is supported in a state of being separated from the main frame and floating, the seat plate is allowed to bend and the synthetic resin seat Even if a seated person sits vigorously by utilizing the elasticity of the board, the impact can be absorbed and a soft sitting comfort can be obtained.

[0007] In addition, Shinkuroro' of claim 1 Symbol placement of chairs
The king device has a front shaft portion that extends in the width direction of the chair on one of the front side of the seat plate and the main frame, and a front locking portion that locks the front shaft portion on the other member in the radial direction. Along with the rear of the seat plate and the backrest support member or the seat plate support member, a rear shaft portion extending in the width direction of the chair ,
The other member is formed with a rear locking part for locking in the radial direction with the rear shaft part, and at least one of the front shaft part and the rear shaft part is supported by the back and forth of the seat plate according to the tilting of the backrest support member. It is configured to be movable in any direction.

In this case, the front portion and the rear portion of the seat plate are attached to the main frame and the backrest support member, respectively, by engaging, for example, hooking the shaft portion and the locking portion. For this reason, they are connected only by fitting the peripheral surface of the shaft portion into the locking portion, and it is less troublesome to mount as compared with screwing or the like.

Further, the seat plate mounting structure according to claim 2 Symbol mounting chairs in synchro locking device according to claim 1 Symbol mounting of the chair, the seat plate is a rear locking portion and the front locking portion is integrally molded synthetic It is a resin molded product, and a through hole is formed at a projection surface position corresponding to the undercut portions of the front locking portion and the rear locking portion. In this case, a seat plate with an undercut can be injection-molded by a general split mold without using a complicated mold such as a slide mold. Moreover, since a jig, such as a driver, can be inserted into the shaft portion from the side opposite to the locking portion where the shaft portion is exposed using the through hole, the shaft hooked on the locking portion The part can be removed using a jig.

Furthermore, the invention of claim 3 Symbol placement is claim 2
In synchronous locking device of the serial mounting of the chair, front become shank and rear shank from one shaft respectively, the longitudinal direction of the shaft seat plate which moves in response to tilting of the backrest carrier of these front and rear shafts It is configured so as to pass through a guide hole formed in a slender shape. In this case, each shaft is formed by passing the shaft through the member on which the shaft is provided in the width direction of the chair. In this case, if the hole through which the shaft passes is an elongated guide hole, the shaft can be moved in the front-back direction of the seat plate, and the backrest support member can be tilted with respect to the main frame.

Furthermore, the invention of claim 4 Symbol mounting, in synchro locking device according to claim 3 Symbol <br/> mounting chairs, the front shaft to the main frame, while attached respectively rear shaft backrest carrier, A retaining wall is provided on each of the seat plates facing the both end surfaces of these shafts. In this case, both ends of the shaft are sandwiched between the retaining walls of the seat plate at the same time when the peripheral surface of each shaft is fitted into each locking portion. That is, even if the shafts are not fixed to the main frame and the backrest support member, the seat plates can be attached to the mainframe and the backrest support member to prevent the shafts from falling off.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The structure of the present invention will be described below in detail based on the best mode shown in the drawings.

1 to 8 show an example of an embodiment of a synchro locking device for a chair according to the present invention. This synchro locking device 1 includes a main frame 4 attached to the upper ends of legs 2, a seat plate 3 of a seat attached to the main frame 4 so as to be swingable, a backrest support member 6 of a backrest, and a backrest. It is provided with a reaction force generation mechanism 5 interposed between the support member 6 and the main frame 4 to generate a reaction force for returning the backrest to the basic posture. A synchronous locking mechanism including the seat plate 3 is attached to each of the backrest support members 6 tiltably connected to the main frame 4 and the seat plate is movable in the front-rear direction according to the tilt of the backrest support member 6. Has been done.

The seat plate 3 (hereinafter referred to as the outer shell, including the seat plate) formed of the outer shell and the main frame 4 are connected to each other either at the front portion of the outer shell 3 or at the main frame 4. A front shaft portion 24 that extends in the width direction of the chair is provided on one of the members, and a front locking portion 32 that locks the peripheral surface of the front shaft portion 24 is formed on the other member, and the back portion of the outer shell 3 and the backrest are supported. A rear shaft portion 29 extending in the width direction of the chair is provided on any one of the support members 6, and a rear locking portion 33 for locking the peripheral surface of the rear shaft portion 29 is formed on the other member, and the front shaft portion is formed. At least one of 24 and the rear shaft portion 29 is movable in the front-rear direction of the outer shell 3 in accordance with the tilting of the backrest support member 6.
In the present embodiment, claw-shaped engaging portions 32 and 33 are formed in front and rear of the outer shell 3, respectively, and shaft portions 24 and 29 formed of shafts are provided on the front and backrest support members 6 of the main frame 4. The front shaft portion 24 is provided so as to be movable 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 integrally formed on the outer shell 3. Each of the locking portions 32 and 33 has, for example, a hook shape as shown in FIG. 5, and two are formed at each of two positions on the left and right sides of the front portion of the outer shell 3 and two positions on each of the left and right sides of the rear portion thereof. 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 need to make an undercut portion in the injection molding dies 34 and 35, so that a simple split mold can be used before and after the hook type without using a complicated mold such as a slide type or a cam type. The locking portions 32 and 33 can be molded. For example, as shown in FIG. 6, it becomes possible to insert the convex portion 34a of the one molding die 34 into the concave portion 35a of the other molding die 35 from the mold matching direction, and the convex portion 34a is formed on the molding die 34 itself. Can be molded, and the mold structure can be simplified. Further, the outer shell 3 has a front locking portion 32.
A retaining wall 3a is formed so as to sandwich the rear locking portion 33. Each retaining wall 3a is provided with each locking portion 32, 33.
When the shafts 24 and 29 that are the front and rear shafts are fitted in the shafts, the shafts 24 and 29 are opposed to both end faces to prevent the shafts 24 and 29 from slipping off in the axial direction. In addition, each locking portion 32,
A tapered rib 37 is formed inside 33,
The shafts 24 and 29, which will be described later, are fitted into the recesses of the rib 37 to prevent the shafts from coming off. The outer shell 3
A cushion 38 is attached to the upper part of the above, and a seat is formed by covering the upper part with a cushioning material.

The main frame 4 is fixed to the top of the leg 2 to support the seat and backrest. In the case of this embodiment, the upper plate 4a and the side plates 4b and 4c are opened on the floor side. It is made of a groove-shaped die cast product, and the reaction force generating mechanism 5, the backrest support member 6, the reaction force adjusting mechanism 19 and the like are housed inside thereof. A hole 8 is formed in the rear portion of the upper plate 4a, and the backrest support member 6 is taken out rearward through the hole 8.

Most of the backrest support member 6 is formed of a solid round bar, but the tip end side of the backrest support member 6 is formed of a plate-like frame so that it can be easily inserted and attached into the main frame 4. The separated swing member 9 is fixed by welding or the like. The swinging member 9 is swingably attached to the main frame 4 by a shaft 10 which is rotatably supported on the cylinder upper portions 4d and 4e of the main frame 4 via sleeves (not shown), and its tip (front end). ) Part is detachably connected to the connecting shaft 11 of the reaction force generating mechanism 5. Therefore, the backrest support member 6 swings around the shaft 10 and at the same time causes the reaction force generation mechanism 5 to store an elastic force. Both ends of the shaft 10 are cylindrical portions 4 formed on the side plates 4b and 4c of the main frame 4.
It is passed through and supported by d and 4e. Each tubular portion 4d, 4e
The outer opening is closed by the covers 12, 12.

The reaction force generating mechanism 5 is interposed between the backrest support member 6 and the main frame 4 to support the backrest in a basic posture P.
To generate a reaction force for returning the backrest support member 6 tilted 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 these Is composed of a connecting shaft 11 for connecting and synchronizing. Each spring unit 14 is an extendable link provided with a coil spring 15. In the case of this embodiment, the coil spring 1
5, spring mounts 16 and 1 attached to both ends
7 and a guide shaft 18 connecting the spring mounts 16 and 17 so as to be movable only in the axial direction form an expandable link. The front side spring mount 16 of each spring unit 14 is on the main frame 4, and the rear side spring mount 17 is on the connecting shaft 11.
Are rotatably connected to the swinging member 9 forming a part of the backrest support member 6 via the. 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 one spring unit 14 and the main frame 4. As shown in detail in FIG. 12, this reaction force adjusting mechanism 19 allows a wedge-shaped piece member 41 to freely move in and out by a screw rod 43 between a bracket 42 on the main frame 4 side and an attachment 44 connected to the spring mount 16. By adjusting the grip 20, the screw rod 43 is rotated to move the positions of the attachment 44 and the front spring mount 16 back and forth to change the precompression amount of the coil spring 15. 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, in a direction in which a space between the sheets 16 and 17 is opened. The basic posture P is a posture in which the backrest support member is raised most when the chair is free and is not used.

In the case of this embodiment, the reaction force generating mechanism 5
A gas damper 13 for fixing the backrest at an arbitrary position and inclination is incorporated in the. The gas damper 13 is for fixing the backrest support member 6 by closing the flow path of the filling gas by operating the lever and locking the length (rod that moves in and out), and the cylinder base end of the gas damper 13 is a shaft attached to the main frame 4. 21, the rod tip is the connecting shaft 11
Are connected to each other so that relative rotation is possible. A lever 22 for operating a valve that closes the flow path of the filling gas is attached to the tip of the gas damper 13. Lever 22
Is a control lever 2 provided on the side of the outer shell 3.
Operated by 3.

The main frame 4 is provided with a mounting hole 4f in the rear boss portion for inserting the upper end of the leg 2, and the upper end of the pillar of the leg 2 is press-fitted into the mounting hole 4f so that the leg 2 is fitted into the leg 2. It is provided so that it can be attached. Further, elongated guide holes 4g are formed in the front-rear direction of the outer shell 3 in front of both side plates 4b, 4c of the main frame 4, and these guide holes 4g serve as the front shaft portion 24 of the slide shaft (hereinafter , Slide shaft 24) penetrates. Therefore, the slide shaft 2
4 is movable in the front-rear direction of the outer shell 3 within a range where each guide hole 4g is formed. Then, by fitting the slide shaft 24 into the hook-shaped front locking portion 32 from the radial direction, the front of the outer shell 3 is connected to the main frame 4. A sleeve 31 made of a sliding material is fitted in each guide hole 4g.

On the other hand, a synchro shaft constituting the rear shaft portion 29 (hereinafter referred to as synchro shaft 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
The rear side of the outer shell 3 is connected to the backrest support member 6 by fitting in the hook-shaped rear locking portion 33 from the radial direction. Each of the shafts 24 and 29 is a mere round bar having no rivet head or a locking means such as a screw formed at its end.

According to the synchro locking device having such a structure, when the seated person leans against the backrest, the backrest support member 6 inclines rearward about the shaft 10. As a result, the tip of the backrest support 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 is generated to return the backrest support member 6 to the basic posture P. 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.

When the seated person tilts the backrest support member 6 to an arbitrary angle and locks the gas damper 13 by operating the operating lever 23, the backrest support member 6 is tilted.
Is fixed in that position so that the backrest and the posture of the outer shell 3 are kept constant. From this state, when the seated person releases the operation lever 23 to allow the gas damper 13 to expand and contract, the backrest support member 6 is unlocked, and the reaction force of each spring unit 14 is generated by the seated person's rising motion. The backrest support member 6 returns to the basic posture P. That is, the backrest and the posture of the outer shell 3 are restored.

Moreover, by attaching the front of the outer shell 3 to the main frame 4 and the rear thereof to the backrest supporting member 6, the outer shell 3 can be attached without using the seat brackets that have been conventionally required. Also, the central portion of the outer shell 3 floats away from the main frame 4, and even when the user sits vigorously, the central portion of the outer shell 3 does not directly hit the main frame 4 and exhibits its elasticity. As a result, the seated person does not feel an unpleasant feeling of bottoming.

Next, the procedure for attaching the outer shell 3 will be described. First, the slide shaft 24 is passed through each guide hole 4g of the main frame 4, and the synchro shaft 29 is passed through a predetermined position of the backrest support member 6.
Next, the shafts 24 and 29 and the front and rear locking portions 32 and 33 of the outer shell 3 are fitted so as to be hooked in the radial direction. At this time, the shafts 24, 29 and the locking portions 32, 3 are utilized by utilizing the through holes 36 under the respective locking portions 32, 33.
For example, a screwdriver or a dedicated jig is inserted from the side opposite to 3, and the shafts 24 and 29 are inserted into the locking portions / pawls 32 and 33 by pushing them inward. The use of each through hole 36 facilitates the use of the jig and improves workability. Also,
By attaching the outer shell 3, each shaft 24, 2
Both ends of 9 will be sandwiched by the retaining wall 3a of the outer shell 3, and even if the shafts 24 and 29 are not fixed to the main frame 4 or the backrest support member 6 in advance, the respective locking portions 32 and 33 It is possible to prevent the falling out of.
That is, since a simple round bar can be used as each of the shafts 24 and 29 and a special fixing member is not required, the number of parts is smaller than that of a mounting structure in which the shaft itself must be processed and nuts and the like must be used. Since the number is small and the assembly process is not necessary, the manufacturing cost can be reduced.

On the other hand, when the outer shell 3 is removed, a jig is inserted from each through hole 36 and each shaft 24,
If 29 is pushed out from the inner side of each locking portion 32, 33, it can be easily removed. Also in this case, the work is facilitated and the workability is improved by using the jigs utilizing the through holes 36. That is,
The outer shell 3 can be removed by simply removing the shafts 24 and 29 from the locking portions 32 and 33, and since the jig can be used easily in this case, the outer shell 3 can be easily removed when the chair is discarded. It can be removed.

Next, FIGS. 9 to 11 show another embodiment of the synchro locking device of the present invention. In this embodiment, the backrest support member 6 is arranged from the side of the main frame 4. In the present embodiment, the backrest support member 6 is handled in a different manner and the support mechanism behind the seat plate 3 is different, but the other elements are common, and detailed description thereof is omitted. Further, the hole 8 formed in the main frame 4 is closed by the cover 30.

In the synchro locking device 1 of this embodiment, the front of the seat plate 3 and the main frame 4 are connected so as to swing and move back and forth, and the rear of the seat plate 3 and the seat plate support member 28 swing. A synchro that moves the seat plate 3 in the front-back direction and slightly moves the seat plate 3 up and down by a seat support member 28 that is movably connected and that rotates in synchronization with the back support member 6 in response to tilting of the back support member 6. It constitutes the locking mechanism.

The seat plate support member 28 is connected to the backrest support member 6 via the connecting shaft 25 and rotates in synchronization with the backrest support member 6. The connecting shaft 25 is incorporated into the tubular portions 4d and 4e 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 is the connecting shaft 25.
It has a square hole similar to the square cross-sectional shape of FIG. The outer diameter of the end portion of the sleeve 27 protruding from the tubular portions 4d and 4e of the main frame 4 is non-circular, for example, rectangular like the connecting shaft, and is a seat support member fitted to the end portion. 28 can be supported so as to rotate together with the connecting shaft.

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

The connecting shaft 25 has a non-circular shape, for example, an angular shape, and projecting portions 25a at both ends thereof are projected from the left and right cylindrical portions 4d and 4e of the main frame 4 so that the square holes 6a of the backrest supporting member 6 are formed. It is press-fitted. A crank lever 26 is connected to the central portion of the connecting shaft 25 so as not to rotate relative to it, and is provided so as to swing the crank lever 26 in conjunction with the backrest support member 6. The reaction force generation mechanism 5 is connected to the tip of the crank lever 26.

That is, as will be described later, the backrest support member 6
The part to which is connected and the part to which the crank lever 26 is connected are formed in a square rod shape. The connecting shaft 25 penetrates through the cylindrical portions 4d and 4e of the main frame 4 and has both ends thereof projected to the left and right. The square holes 6a of the backrest support member 6 are fitted into the respective projecting portions 25a,
The connection shaft 25 and the backrest support member 6 are connected to each other so that they cannot rotate relative to each other.

Further, the connecting shaft 25 and the tubular portions 4d,
Sleeves 27 are fitted in between 4e and 4e, respectively. The hole of each sleeve 27 has a square hole shape and cannot rotate with respect to the connecting shaft 25. In addition, the outer peripheral surface of each sleeve 27 is formed into a round bar shape inside the portion including the portions fitted into the tubular portions 4d and 4e, and the tubular portions 4d and 4e, that is, the main frame 4 is formed.
It is rotatable with respect to. On the other hand, each sleeve 27
A portion of the outer peripheral surface outside the portion fitted into the cylindrical portions 4d, 4e is formed into a square rod shape, and the seat support members 28 are fitted into the square rod portion such that they cannot rotate relative to each other. That is, the seat supporting member 28 is connected to the connecting shaft 25 with each sleeve 27 interposed, and the seat supporting member 28 and the sleeve 27 and the sleeve 27 and the shaft 25 are connected.
Since the connecting portion of is formed into a square bar shape, each seat support member 28 cannot rotate with respect to the connecting shaft 25.

A synchro shaft 29 is attached to the tip of each seat support member 28, and the synchro shaft 29 is fitted in the rear locking portion 33 of the seat plate (or the seat frame fixed to the seat plate 3). Therefore, the weight of the seated person directly acts on each seat supporting member 28, but since the sleeve 27 into which each seat supporting member 28 is fitted is formed thicker than the connecting shaft 25, the seat plate 3 has a large rigidity.
Can support. The synchro shaft 29 is connected to the backrest support member 6 although each seat support member 28, each sleeve 27, and the connecting shaft 25 are interposed, so that the rear portion of the seat plate 3 is attached to the backrest support member 6. It will be. In this embodiment, the seat plate 3 is provided with seat frames having holes through which the shafts 24 and 29 penetrate, but the present invention is not limited to this, and the outer shell also serves as the seat plate 3. It may be done.

Two crank levers 26 are provided corresponding to the pair of spring units 14 of the reaction force generating mechanism 5. Each crank lever 26 is integrally formed with each sleeve 27, and its forked end is connected to the connecting shaft 11 of the reaction force generating mechanism 5, respectively.

According to the synchro locking device having such a structure, when the seated person leans against the backrest, the backrest support member 6 tilts rearward while rotating the connecting shaft 25 and the sleeve 27. As a result, the crank lever 26 pushes and contracts the gas damper 13 of the reaction force generating mechanism 5 and each spring unit 14. Each spring unit 1
When the coil spring 15 of No. 4 is compressed, a reaction force for returning the backrest support member 6 to the basic posture P is generated. Further, since each seat support member 28 also rotates due to the rotation of each sleeve 27, the seat plate 3 also moves rearward while moving the slide shaft 24 in the front-back direction within the guide hole 4g in conjunction with the inclination of the backrest support member 6. Incline to sink.

When the seated person tilts the backrest supporting member 6 to an arbitrary angle and locks the gas damper 13 by locking the operating lever 23, the sleeves 27 and the connecting shaft 25 cannot rotate. Back support member 6
Is locked. Therefore, the backrest and the posture of the seat plate 3 are held constant. From this state, when the seated person releases the operation lever 23 to allow the gas damper 13 to expand and contract, the backrest support member 6 is unlocked, and the reaction force of each spring unit 14 is generated by the seated person's rising motion. The backrest support member 6 returns to the basic posture P. That is,
The backrest and the posture of the seat plate 3 can be returned to their original positions.

Further, with the synchro locking device constructed as described above, the seat plate 3 can be mounted on the main body of the seat plate 3 simply by fitting the engaging portions 32 and 33 of the seat plate 3 onto the shafts 24 and 29 so as to be caught in the radial direction. It is attached to the frame 4 and the seat support member 28. That is, as in the embodiment of FIGS. 1 to 8, the seat bracket is not required and the seat plate 3 can be attached in the same procedure, so that the productivity can be improved. Further, since the central portion of the seat plate 3 is attached in a floating state, there is no feeling of bottoming,
Further, since the seat plate 3 can be tilted in association with the backrest, the sitting comfort can be improved.

In the above-described synch locking device 1 of the present invention, it is possible to mount a backrest having a completely different impression design on a common synch locking mechanism only by changing the manner of handling the back support member 6. . That is,
When manufacturing a chair of the type in which the backrest support member 6 is attached to the rear of the main frame 4, the backrest support member 6 is swingable by the shaft 10 on the main frame 4 with the reaction force generation mechanism 5 assembled. While connecting, the tip of the backrest support member 6 is connected to the connecting shaft 1 of the reaction force generating mechanism 5.
You can connect it to 1. When manufacturing a chair of the type in which the backrest support member 6 is attached to the left and right of the main frame 4, the connecting shaft 25 and each sleeve 27 are attached to the main frame 4 with the reaction force generation mechanism 5 attached. The tip of the crank lever 26 is connected to the connecting shaft 11, and the seat support member 2 is attached to each sleeve 27.
It is only necessary to fit the right and left backrest support members 6 after fitting 8.

In this way, since one synchro locking device 1 can be applied to chairs having different mounting positions of the backrest support member 6, common parts can be used and the production cost can be reduced. At the same time, it is possible to flexibly respond to the diversification of design.

The above-described embodiment is an example of the preferred embodiment of the present invention, but the present invention is not limited to this, and various modifications can be made without departing from the gist of the present invention. For example, in the above description, the locking portions 32 and 33 are formed in the outer shell 3 and the shafts 24 and 29 are supported by the main frame 4 and the backrest support member 6, but the outer shell 3 side Each shaft 24,
29 may be supported, and the locking portions 32 and 33 may be formed on the main frame 4 and backrest support member 6 sides.

In the above description, each shaft 24,
Of the 29, the one on the front side is movable back and forth, but the one on the rear side may be movable back and forth, or the one on both sides may be movable back and forth.

Further, in the above description, the shaft 2 separate from the main frame 4 and the backrest support member 6 is used as each shaft portion.
Although 4 and 29 are used, it goes without saying that they are not limited to shafts. For example, a pin integrally molded with the outer shell 3 by a synthetic resin, or a pin integrally molded with the main shaft by metal may be used instead.

In the above description, the outer shell 3
Although each retaining wall 3a is formed on the shaft to prevent the shafts 24 and 29 from falling off in the axial direction, it is not always necessary to form each retaining wall 3a. However, in this case, for example, each shaft portion is configured by a long shaft bolt,
It is preferable to prevent the falling by fixing the bolt with a nut.

In the above description, the backrest support member 6
Although the tip end portion of the rocking member 9 is formed as a separate body, it may not be necessarily formed as a separate body and may be integrally molded.

Further, 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.

[0047]

As is apparent from the above description, according to the first aspect of the present invention, since the synchro locking mechanism is constituted by including the seat plate, the seat which is required in the conventional seat plate mounting structure is provided. The bracket can be omitted.
Therefore, the cost can be reduced and the productivity can be improved by reducing the number of parts and the number of assembling steps. Also, the front and rear of the seat plate are attached to the main frame and the backrest support member, and since the center part of the seat plate is supported in a state of being separated from the main frame and floating, the seat plate is allowed to bend and the synthetic resin seat Even if a seated person sits vigorously by utilizing the elasticity of the board, the impact can be absorbed and a soft sitting comfort can be obtained.

[0048] According to the invention of claim 1 Symbol placement, rest front and rear portion and the main frame by a respective hook example engagement of the shaft portion and the locking portion back of seat plate support member or the seat plate
It is attached to the support member . For this reason, they are connected only by fitting the peripheral surface of the shaft portion into the locking portion, and it is less troublesome to mount as compared with screwing or the like. Therefore, the chair assembly process can be simplified. Further, since the seat plate can be removed by removing each shaft portion from each locking portion, disassembly at the time of discarding a chair becomes easy.

[0049] According to the invention of claim 2 Symbol placement, be injection molded seat plate with undercut a general split type without using a complicated mold such as a slide type. Moreover,
A jig, such as a screwdriver, can be inserted from the opposite side of the locking part where the shaft is exposed using the through hole to reach the shaft, so the shaft hooked on the locking part It can be removed using a jig. Accordingly, the chair assembling process can be simplified, the cost of the mold can be reduced, and the mold can be easily maintained.

[0050] Further, according to the invention of claim 3 Symbol mounting, the shaft becomes movable in the front-rear direction of the seat plate if elongate guide hole hole into which a shaft, a tilting of the backrest carrier relative to the main frame to enable.

[0051] Further, according to the invention of claim 4 Symbol mounting, since both ends at the same time the shaft when fitting the peripheral surfaces of the shafts to each engaging portion is sandwiched between the stopper wall of the seat plate, the main Even if the shafts are not fixed to the frame and the backrest support member, the shafts can be prevented from falling off by attaching the seat plate to the main frame and the backrest support member. Therefore, the assembly process of the chair can be further simplified.
Further, since each shaft can be a simple rod-shaped one, the manufacturing cost can be further reduced.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an example of an embodiment of a synchro locking device for a chair according to the present invention immediately before a seat plate is attached.

FIG. 2 is a perspective view showing a state where a seat plate is attached to the synchro locking device of FIG.

3 is a side view showing a schematic configuration in which a seat plate is attached to the synchro locking device of FIG. 1. FIG.

FIG. 4 is a side view showing a schematic configuration in a state where a seat plate is attached to the synchro locking device of FIG.

FIG. 5 is an enlarged cross-sectional view showing a locking portion of the synch locking device of FIG.

FIG. 6 is a cross-sectional view of a mold for molding a locking portion of the synch locking device of FIG.

FIG. 7 is a bottom view of the synchro locking device of FIG. 1 viewed from below.

FIG. 8 is a perspective view of the synchro locking device of FIG. 1 viewed from diagonally above.

FIG. 9 is a side view schematically showing another embodiment of the synchro locking device of the present invention.

FIG. 10 is a bottom view of the synchro locking device of FIG. 9 as seen from below.

FIG. 11 is a perspective view of the synchro locking device of FIG. 9 seen from diagonally above.

FIG. 12 is a cross-sectional view showing in detail a reaction force adjusting mechanism of the synchro locking device of the present invention.

[Explanation of symbols]

1 Synchro locking device Two legs 3 Outer shell (seat plate) 3a retaining wall 4 mainframe 4g guide hole 5 Reaction force generation mechanism 6 Back support member 24 Slide shaft (front shaft) 29 Synchronous shaft (rear shaft) 32 Front locking part 33 Rear locking part 36 through holes

Claims (4)

(57) [Claims] 1. A synchro locking device, which is attached to the upper ends of the legs and tiltably supports a seat and a backrest in an interlocking manner, and a main frame attached to the upper ends of the legs, and swings with respect to the main frame. A seat plate of the seat and a backrest support member of the backrest that are movably attached, and a reaction force that is interposed between the backrest support member and the main frame to return the backrest to a basic posture. A reaction force generating mechanism, and swingably connects the front of the seat plate, the main frame, the rear of the seat plate, and the backrest support member or a seatplate support member that rotates in synchronization with the backrest support member. In addition, at least one of the seat plate and the main frame or the backrest support member or the seat plate support member is connected to the front of the seat plate according to the tilt of the backrest support member. It is movable in the rearward direction and supports the center portion of the seat plate in a state of being floated away from the main frame, and a synchro locking mechanism is configured including the seat plate, and Forward
And the width of the chair on either member of the main frame above
The front shaft that extends in the same direction as the front shaft on the other member.
Form a front locking part that locks in the direction of
And the backrest support member or the seat plate support member
The rear axle that extends in the width direction of the chair is
A rear locking portion that is radially locked to the rear shaft portion on the member of
Each of them is formed and at least one of the front shaft part and the rear shaft part is formed.
One of the seats is attached to the seat plate according to the tilting of the backrest support member.
Synchronous locking device for chairs, which is movable in the front-back direction . 2. The projection plate corresponding to an undercut portion of the front locking portion and the rear locking portion, wherein the seat plate is a synthetic resin molded product in which the front locking portion and the rear locking portion are integrally molded. synchronizer locking device according to claim 1 Symbol mounting of the chair, characterized in that the through-holes in positions are formed. 3. The front shaft portion and the rear shaft portion are each one shaft, and among the front and rear shafts, the shaft that moves according to the tilt of the backrest support member is elongated in the front and rear direction of the seat plate. synchronizer locking device according to claim 2 Symbol mounting chairs, characterized in that through the formed guide hole. 4. The front shaft is attached to the main frame, the rear shaft is attached to the backrest support member, and the retaining plates are provided on the seat plates at positions facing both end surfaces of the shafts. synchronizer locking device according to claim 3 Symbol mounting of the chair and said.