JP3130277B2 - Locking device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a locking device. More specifically, the present invention relates to a locking device in which a movable member such as a back or a seat is rotatably attached to a fixed member such as a leg of a chair so as to be able to tilt backward.

[0002]

2. Description of the Related Art In the case of a chair which can be tilted backward, usually called a rocking chair, for example, in the case of a swivel chair, a back support rod portion of a back can swing freely on a seat receiving member supported by legs. The compression coil spring is interposed between the spring force adjusting screw supported by the seat receiving member and the back support rod, and the back support rod is elastically supported so as to be able to tilt backward. Further, in a chair having four legs, the locking mechanism is generally configured as one independent finished product, and the locking mechanism is attached to the legs so that the locking mechanism supports the seat and the backrest. It is customary.

[0003]

However, it is difficult to apply the above-described support structure for the back of a swivel chair to a chair having a pipe frame structure in which a seat is supported between a front leg and a rear leg. Also, a compression spring for supporting the back, a screw for fixing the compression spring, and the like are exposed to the outside, so that the appearance may be impaired.

In the case where the locking mechanism is formed as one independent completed product, bulkiness is suppressed because the locking mechanism is disposed in a limited space between the leg and the seat or back. Therefore, it must be made as compact as possible. In addition, many components are used and built-in so as to provide an independent locking function by itself. For this reason, not only is it difficult to reduce the number of steps and cost, but also if it is attempted to make the whole compact, there is a problem that it is difficult to obtain an appropriate locking function without applying a large load because individual components become small. .

There is also a chair that connects a back and a seat with a torsion bar interposed. In this case, since fittings for attaching the torsion bar are welded to the back and the seat, there is a problem that the assembling accuracy is not stable due to distortion due to welding. Also, since the welded part is exposed outside,
Design considerations such as attaching a cover are required.

An object of the present invention is to provide a locking device having a simple structure and appearance. Another object of the present invention is to provide a locking device that can be installed as a single pipe without a mounting structure being visible from the outside when applied to a chair or the like.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a chair having a back which can be tilted rearward with a lower end pivotally attached to a leg. A member and a torsion bar coaxially arranged in the tubular member are provided, while the tubular member is fixed to either the leg or the back, and a slit is formed in the tubular member.
To form, fixed by penetrating the slit to secure the other of <br/> movable member or fixed member to the torsion bar, and is a central tubular member of the torsion bar by caulking from the outer tubular member I am trying to be.

Therefore, according to this chair, when weight is applied to the back, the torsion bar is relatively twisted in accordance with the load, so that rotation of the back is permitted and force for returning the back is provided. Is stored in the torsion bar. Moreover, the torsion bar is completely hidden inside the tubular member, and the attachment of the torsion bar and the tubular member is performed not by welding but by caulking from the outside of the tubular member and is integrally performed at the time of forming the pipe, so that it can be seen from the outside. Connection points do not appear.

According to a second aspect of the present invention, in the locking device of the first aspect, the fixing member is a leg of a chair, and the movable member is a back or a seat or both.

[0010]

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

FIGS. 1 to 4 show an embodiment in which the locking device of the present invention is applied to a chair. The chair comprises a tubular member 4 between a fixed member and a movable member, that is, between the leg 1 and the back 2, and a torsion bar 3 coaxially arranged in the tubular member 4. Is fixed to the leg 1 and both ends of the torsion bar 3 are fixed to the back 2, so that the lower end of the back 2 (the lower end of the back support rod 2a) is rotatably attached to the leg 1 and tilts backward. Made possible.

The leg 1 is composed of a self-supporting pipe frame having a substantially trapezoidal shape in which a front leg 1a and a rear leg 1b are connected to a seat frame 1c. Here, seat frame 1
The rear end c and the rear leg 1b are connected to each other by a horizontal member (hereinafter, referred to as a horizontal member 4) composed of a tubular member 4.
The horizontal member 4 forms a part of the seat frame 1c and also forms the leg 1.

The torsion bar 3 is inserted in the hollow portion of the horizontal member 4. As shown in FIGS. 3 and 4, the center of the torsion bar 3 is fixed to the horizontal member 4 via the mounting bracket 3a, and the torsion bar 3 is supported by the cap member 7 so that both ends can rotate freely. ing. The torsion bar mounting bracket 3a and the horizontal member 4 are fixed to each other.
It is performed by caulking 6 from outside. Since the caulking 6 is performed integrally when the horizontal member 4 is formed into a pipe, the connecting portion does not appear even when viewed from the outside.

At both ends of the torsion bar 3, slits 8 formed on the peripheral surface near both ends of the horizontal member 4 are provided.
And the lower end of the back support rod 2a (the lower end of the so-called back 2)
Is fixed. Therefore, since both end portions 3b can freely rotate with respect to the central portion 3a fixed to the horizontal member 4, the torsion bar 3 accumulates elastic force while being twisted.

The back 2 is composed of a back support rod 2a and a back plate 2b supported by the back support rod 2a. The lower end of the back support rod 2a has slits 8 provided near both ends of the horizontal member 4. And is fixed to both ends 3b of the internal torsion bar 3 so that the torsion bar 3 is supported by the leg 1 so as to be able to tilt backward. The back 2 can perform a backward tilting operation around the axis of the torsion bar 3 while twisting the torsion bar 3. Further, in the case of the pipe chair of the present embodiment, the seat 5 is composed of a seat frame 1c constituting a part of the leg 1 and a seat body 5a having elasticity supported by the seat frame 1c. The seat body 5c is fixed and supported substantially horizontally.

According to the chair configured as described above, the locking function can be obtained as follows.

That is, when the seated person leans on the back 2, the back 2 is rotated around the axis as a whole while twisting the torsion bar 3 in accordance with the load, and moves backward as shown by the phantom line in FIG. Tilt to sink. As a result, the angle between the back 2 and the seat 5 is widened, and the whole chair is in a state where the seated person can take a comfortable posture. On the other hand, when the seated person cannot lean on the back 2, the torsion bar 3
The back support rod 2a pivots forward around the torsion bar 3 by the elastic force stored in the torsion bar 3, and the back 2 returns to its original position. Therefore, the angle between the back 2 and the seat 5 is in a state where it can take a posture suitable for work or the like.

Thus, in the chair of the present embodiment, the locking function is exerted on the whole chair. Therefore, compared to the case where an independent locking mechanism is configured, it is not necessary to bring unnecessarily many parts into a limited space, and the strength of the components of the chair is used as it is as the strength of the locking mechanism. As a result, it becomes easy to provide an appropriate locking function, and at the same time, it is possible to easily increase the strength with respect to the load and effectively improve the reliability and durability. In addition, the torsion bar 3 can easily set a large elastic force, and it is possible to effectively increase the degree of freedom in designing the locking function.

The above embodiment is an example of a preferred embodiment of the present invention, but the present invention is not limited thereto, and various modifications can be made without departing from the gist of the present invention. For example, in the present embodiment, the back support rod 2a is fixed to the torsion bar 3 and the horizontal member 4 as a tubular member is fixed to the leg 1 side. However, the present invention is not limited to this, and the mounting relation may be reversed. . That is, both ends of the torsion bar 3 may be fixed to and supported by the leg 1, while the tubular member 4 may be fixed to the back support rod 2a.

In this embodiment, the case where the present invention is applied to a chair in which only the back is fixed to a seat or a leg which can be swung is mainly described. However, the present invention is not particularly limited to this. The seat 5 may be swingably supported in the front-rear direction with respect to the leg 1 with a tubular member 4 interposed therebetween.
It is also possible to apply the present invention to a chair as a locking mechanism that changes the inclination in conjunction with the chair 5.

The back and / or seat of a chair (generally referred to as a swivel chair) in which a seat is rotatably supported on a column (in some cases a gas spring is built in) via a seat bracket is provided. You may make it support via the locking device of this invention.

[0022]

As is apparent from the above description, according to the first aspect of the present invention, the torsion bar is completely hidden inside the tubular member, and the attachment of the torsion bar and the tubular member is not by welding, but by tubular welding. Since the members are integrally formed at the time of pipe forming by caulking from the outside, the connecting portion does not appear even from the outside. Moreover, since the tubular member and the torsion bar that constitute a part of the leg are arranged coaxially,
The pipe is simple in appearance, there is no wasted space and no space is required.

Therefore, according to the present invention, a locking device can be realized with a simple structure and without adding special members to the outside. In other words, the number of parts, the number of manufacturing steps, and the cost can be significantly reduced as compared with the conventional case, and the strength of the components of the chair can be directly used as the strength of the locking mechanism, so that an appropriate locking function can be provided.
Reliability and durability can also be increased without difficulty.

According to the second aspect of the present invention, a chair having a locking function with a simple structure can be realized.

[Brief description of the drawings]

FIG. 1 is a side view showing an example in which a locking device according to an embodiment of the present invention is applied to a chair.

FIG. 2 is a plan view showing a half from the center of the frame structure of the chair of FIG. 1;

FIG. 3 is a longitudinal sectional view showing a relationship between a torsion bar and a tubular member.

FIG. 4 is a cross-sectional view showing a relationship between a torsion bar and a tubular member.

[Explanation of symbols]

 Reference Signs List 1 leg (fixed member) 2 back (movable member) 3 torsion bar 3a torsion bar mounting bracket 3b both ends of torsion bar 4 horizontal member (tubular member) 5 seat (movable member) 6 caulking

──────────────────────────────────────────────────続 き Continued on the front page (56) References JP-A 2-107349 (JP, U) JP-A 62-188248 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) A47C 3/00-7/74

Claims (2)

(57) [Claims] 1. A locking device for rotatably mounting a movable member on a fixed member, comprising: a tubular member between the fixed member and the movable member; and a torsion bar coaxially disposed in the tubular member. The tubular member is fixed to either the fixed member or the movable member, and a slit is formed in the tubular member.
Form and, by penetrating the slit solid <br/> constant one other of <br/> said movable member or said fixed member to said torsion bar, and is a central and said tubular member of said torsion bar A locking device, which is fixed by caulking the tubular member from outside. 2. The locking device according to claim 1, wherein the fixed member is a leg of a chair, and the movable member is a back and / or a seat.