JP2001008772A - Locking structure of chair - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chair which can assure an adequate locking state by slowly backward tilting a backrest in a state of simple assembly. SOLUTION: A supporting shaft 20 is passed through movable plates 17 which move back and forth cooperatively with the tilting of the backrest and friction plates 21 which impart friction resistance to the movement of the movable plates 17. The supporting shaft 20 is mounted at a case 22. The supporting shaft 20 is provided with collars 24 and 25 and a cam 27 for changeover. As a result, the entire part of the resistance imparting means is formed as a unit and, therefore, the mounting to a seat receiving body 2 is simplified and eventually, the efficiency of the assembly work of the chair is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chair locking structure having a backrest that can be tilted rearward.

[0002]

2. Description of the Related Art In a chair having a backrest capable of tilting backward, a gas cylinder is generally used as a means for holding the backrest in an arbitrary backward tilting posture, but this has problems in cost and space. .

Therefore, as described in, for example, Japanese Utility Model Publication No. Sho 63-28921 and Japanese Utility Model Publication No. Hei 3-37465, a friction plate is sandwiched between a plurality of movable plates that move in conjunction with the backward tilt of the backrest. A lock device has been proposed in which a movable plate and a friction plate are brought into close contact with a pressing device such as a cam type or a screw type to hold the movable plate immovably so that the backrest can be held in an arbitrary backward tilted posture. ing.

[0004]

The lock device using the movable plate and the friction plate has the appearance of a variable-conversion variable condenser such as a radio, etc., and has a simple structure, but is tilted backward with the backrest. Although there is an advantage that the angle can be adjusted steplessly, on the other hand, the conventional variable-container-type lock device has parts such as a movable plate and a friction plate separated before being assembled to a chair, and these parts are separated. There is a problem that the assembling work of the chair is troublesome because the group of parts must be attached to the seat receiver.

On the other hand, the backrest tilts backward against the spring means. However, as the backrest tilt angle increases, the body of the person tends to slide backward. The rate of increase of the moment acting on the backrest tends to be larger than the rate of increase of the tilt angle.
For this reason, the conventional chair has a problem in that when a seated person leans against a backrest, the backrest leans backwards in a very short time like a stomach, and lacks comfort.

[0006] On the other hand, it is considered sufficient to increase the spring force of the spring means. However, simply increasing the spring force of the spring means makes it difficult for the backrest to excessively lean backward in the initial stage of backward inclination. This also lacks comfort. That is, it was not possible to secure the comfort by applying an appropriate reaction force to the person's back over the entire range of the backward tilt of the backrest simply by adjusting the initial elastic force of the spring means.

More specifically, if the backrest simply tilts backward against the elastic resistance of the spring means, the elastic force of the spring means excessively acts on the back of the person. Therefore, it was not possible to create a supporting state, and there was a limit to improving the comfort in the rocking state.

The object of the present invention is to improve these situations.

[0009]

According to the first aspect of the present invention, a seat and a backrest are mounted on a seat receiving body provided at an upper end of a leg so that at least the backrest tilts rearward. In a chair provided with a resistance applying device provided with a suitable number of movable plates that move in conjunction with the tilting of the backrest, and a friction plate that applies resistance to the movement of the movable plate, It is characterized in that the friction imparting means is unitized by integrally incorporating the friction plate and the case into the unit, and the case is fixed to the seat receiving body.

The resistance applying means in the present invention may function as a lock means for holding the backrest in an arbitrary backward tilted posture, but at least a state in which the backrest is allowed to tilt backward. It is preferable to set a state in which frictional resistance can be imparted to the movable plate by using.

Further, when the resistance applying means functions as the locking means, a lock state in which the friction plate is strongly pressed against the movable plate so that the movable plate cannot be moved, and a free state in which the movable plate can freely move. It is necessary to provide a resistance adjustment device (switching device) for switching. Furthermore, the resistance adjusting device that adjusts (switches) the degree of close contact of the friction plate with the movable plate allows the movable plate to move freely in a free state where it can move freely without resistance and in a state where a moderate resistance is given. It is also possible to set so that at least two states can be selected from three states of an intermediate state and a locked state in which the movable plate cannot move at all.

[0012]

According to the present invention, since the resistance applying means having the movable plate and the friction plate is unitized, the chair can be assembled efficiently.

According to the second aspect of the present invention, when the seated person leans against the backrest, resistance is given to the rearward tilting of the backrest due to frictional resistance between the movable plate and the friction plate. It can retain the hysteresis loss function of tilting over a reasonable time, in other words, it can tilt the backrest while supporting the back of the person slowly, and as a result, comfort in the rocking state Can be significantly improved.

[0014]

Next, embodiments of the present invention will be described with reference to the drawings.

1st Embodiment (FIGS. 1 to 10) FIGS. 1 to 10 show a first embodiment. FIG. 1 is a right side view of a chair, and FIG. 2 is a view taken along the line II-II of FIG. FIG. 3 is a sectional view of FIG.
FIG. 4 is a sectional view taken along line IV-IV of FIGS. 2 and 5, FIG. 5 is a plan sectional view of a main part, and FIG. 6 is a sectional view taken along line VI- of FIGS. 2 and 5.
7 is a partially cutaway front view of the part, FIG. 8 is a view showing an operation, and FIGS. 9 and 10 are views showing an assembling procedure.

As shown in FIGS. 1 to 3, the chair includes a seat 2 fixed to the upper end of a pillar (gas cylinder) 1, a seat 3, and a backrest 4. The seat receiver 2 is formed in a box shape opened upward, and its rear portion is
Has been fitted. A long hole 5 is formed in a front part of the left and right side plates 2a of the seat body 2 in a rearwardly inclined shape, while a U-shaped base 6 in a front view is fixed to a lower surface of the seat body 3, The front ends of the left and right side plates 6a of the base 6 and the seat receiver 2
The first shaft 7 passes through the long hole 5. A guide bush 8 made of synthetic resin is fitted in the elongated hole 5 of the seat receiver 2.

The backrest 4 is attached to a substantially L-shaped back support 9 in a side view, and the front end of the back support 9 is rotatably attached to the rear of the seat receiver 2 by a second shaft 10. Furthermore, the base 6 in the front and rear halfway of the back support 9 and the seat 3
Is rotatably connected to the side plate 6 a by a third shaft 11. The back support 9 is not limited to an integral type as shown in the figure, but may be a type in which a pair of back supports 9 are arranged on both left and right sides of the seat receiver 2.

A coil spring 12 as an example of a spring means is disposed inside the seat receiving body 2 so as to extend in the front-rear direction. The front end of the coil spring 12 is supported by a front spring receiver 13 fitted on the first shaft 7.
The rear end is supported by a rear spring receiver 15 supported by a wedge member 14 so as to be able to move back and forth. The spring means is not limited to a coil spring, and the spring means such as the coil spring 12 may not be arranged as shown in the figure.

As can be understood from the above description, when the seated person leans on the backrest 4, the backrest 4 and the back support 9 tilt backward about the second shaft 10 against the coil spring 12, and The seat 3 is tilted rearward while being retracted and guided by the elongated hole 5. That is, the backward movement and the backward movement of the seat 3 and the backward movement of the backrest 4 are synchronized (linked). Needless to say, the rate at which the backrest 4 leans backward is smaller than the rate at which the backrest 4 leans backward.

As shown in FIGS. 2 and 4 to 10, a resistance applying means 16 for suppressing the back and forth tilting movement of the backrest 4 is provided inside the seat receiver 2. Resistance applying means 16
Is provided with three movable plates (movable bodies) 17 made of a metal plate extending in the front-rear direction.
A round hole 18 that fits into the shaft 7 is open. An elongated hole 19 extending in the front-rear direction is provided at a position from the rear end of each movable plate 17, and a support shaft 20 penetrates the elongated hole 19. Support shaft 20
A ring-shaped friction plate (friction body) 21 is fitted in a portion between adjacent movable plates 17. The friction plate 21
For example, it is possible to use various materials such as a synthetic resin or rubber made of a material having a large frictional resistance, or a metal plate coated with grease.

Further, the rear portion of each movable plate 17 and the friction plate 21
Is covered with a U-shaped case 22 (which may be referred to as a holder) facing downward when viewed from the front, and the support shaft 20 penetrates through the left and right side plates of the case 22. The case 22 is fastened to the seat receiver 2 with an appropriate number of screws 23. Support shaft 2
0, collars 24 and 25 are fitted on both sides of the group of the movable plate 17 and the friction plate 21, respectively. Of these, the collar 24 closer to the coil spring 12 penetrates through the case 22. An outwardly extending cylinder portion 24a is provided integrally (the collar 24 and the cylinder portion 24a may be separate bodies), and the support shaft 20 has a flange 20 for preventing the cylinder portion 24a from coming off.
a. Further, a spring 26 for returning to the free state is fitted in the cylindrical portion 24a.

The end of the support shaft 20 close to the side plate 2a of the seat receiver 2 is exposed outside the case 22.
A cam 27 formed in a U-shape in a plan view is fitted to the end of the “0”, and a pin (screw) 28 extending in the front-rear direction is
And is rotatably mounted via the support shaft 20. Cam 27
Are formed with first and second two cam surfaces 29 and 30 that are in contact with the side surface of the case 22. The two cam surfaces 2 are formed by rotating the cam 27 around the pin 28.
9 and 30 can be selectively applied to the side surface of the case 22. A lever 32 is screwed into the cam 27 via a vertically long window hole 31 formed in the side plate 2a of the seat receiver 2.

As shown in FIG. 7, the shortest distance L1 from the axis of the pin 28 to the first cam surface 29 is larger than the shortest distance L2 from the axis of the pin 28 to the second cam surface 30. You have set. Therefore, when the lever 27 is operated to rotate the cam 27, the support shaft 20 slides in the longitudinal direction, whereby the movable plate 17 and the friction plate 21 can be brought into close contact with or separated from each other. it can.

In this embodiment, when the first cam surface 29 is in contact with the case 22, no frictional resistance is generated between the movable plate 17 and the friction plate 21, and the second cam surface 30 is When it comes into contact with the side surface of the case 22, the movable plate 17 and the friction plate 21 come into close contact with each other, as shown in FIG. The movable plate 17 is allowed to move against the resistance (backrest 4).
Can tilt).

Therefore, when the seated person leans against the backrest 4, the backrest 4 tilts backward against the elastic restoring force of the coil spring 12, and a frictional resistance is generated between the movable plate 17 and the friction plate 21. By doing so, the backrest 4 does not lean backward in a short time in the sense of a stone, but slowly leans backward over a certain period of time, and as a result, a hysteresis loss effect is exhibited, and A proper locking state can be ensured.

In mounting the resistance applying means 16, first, as shown in FIG.
After fixing the case 22 to which the shaft 20, the support shaft 20 and the cam 27 are attached to the seat receiving body 2 with screws 23, the lever 32 is attached to the cam 27 with a root, and before and after this, FIG. As shown, the first shaft 7 may be passed through the round hole 18 of each movable plate 17 (temporarily fixed with the screw 23 at the stage of FIG. 9, and after the first shaft 7 is inserted through the movable plate 17). The screw 23 may be fully tightened).

As described above, since the resistance applying means 16 in which the components such as the movable plate 17 and the friction plate 21 are attached to the case 22 is unitized, the assembling work of the chair can be performed efficiently. The number of the movable plates 17 and the number of the friction plates 21 can be arbitrarily set as needed. Further, the shape can be set as appropriate.

Second Embodiment (FIGS. 11 and 12) FIGS. 11 and 12 show a second embodiment. In this embodiment, a male screw portion 20 a is formed on the support shaft 20, which is screwed into the case 22, and the support shaft 20 is rotated by the handle 33 so that the degree of close contact between the movable plate 17 and the friction plate 21 is reduced. It can be adjusted steplessly.

In this embodiment, by adjusting the degree of screwing of the support shaft 20, a free state where no frictional resistance is generated on the movable plate 17 as shown in FIG.
As shown in FIG. 2, it is possible to switch between an intermediate state in which frictional resistance is given while the movable plate 17 is allowed to move, and a locked state in which the movable plate 17 is fixed in a completely immovable state.

In the intermediate state, the magnitude of the resistance can also be adjusted according to the user's preference (by adjusting the initial elastic force of the spring means and the resistance, it is possible to adjust the hysteresis and the resistance precisely corresponding to the preference of the person). Loss state can be realized). In this example, the window hole 31 of the seat receiver 2 is cut and raised upward. Instead of directly attaching the handle 33 to the spindle 20, a rod with a handle may be attached to the spindle 20.

{Third Embodiment (FIG. 13)} FIG.
1 shows an embodiment. In this embodiment, pressing rings 34 and 35 are arranged on both sides of the group of the movable plate 17 and the friction plate 21 fitted on the support shaft 20, and a spring 36 is interposed between one pressing ring 34 and the inner surface of the case 22. Then, a cylindrical end cam 40 having three high, middle, and low cam surfaces 37, 38, and 39 is fitted between the other holding ring 35 and the inner surface of the case 22 on the support shaft 20.
In addition, a foot 35a that can selectively contact each of the cam surfaces 37, 38, 39 of the cam 40 is integrally provided.

A rod 41, to which a handle (not shown) is attached, is attached to the cam 40 so as not to rotate relatively. The support shaft 20 and the other holding ring 35 are held so as not to rotate. In this embodiment, when the low-stage cam surface 37 of the cam 40 corresponds to the foot 35a of the other pressing ring 35, no frictional resistance acts on the movable plate 17, and the backrest 4 is It is in a free state in which it tilts backward against only 12.

On the other hand, by rotating the handle 33, the cam 4
0 of the middle cam surface 38 to the foot 35 of the other pressing ring 35.
a, the movable plates 17 and the friction plates 21
The movable plate 17 is brought into close contact with a moderate force via a spring 36, and a frictional resistance is generated in an intermediate state where the movable plate 17 is allowed to move.
Further, the high-stage cam surface 39 of the cam 40 is
In a state in which the movable plate 17 and the friction plate 21 are in close contact with each other via the spring 36 in a state where the movable plate 17 is in contact with the foot 35a of the fifth 5, the movable plate 17 is immovably locked.

{Others} As shown in FIG. 14 as a fourth embodiment, the degree of close contact between the movable plate 17 and the friction plate 21 may be adjusted by a screw-in type handle 33 and a spring 36. As shown in FIG. 15 as a fifth embodiment, the movable plate 17 may be formed with a notch groove 42 to be fitted on the first shaft 7 from above, so that the assembling work can be more easily performed. It gets even easier.

The embodiment of the present invention has been described above.
The present invention can be further embodied in various aspects. For example, the present invention can be applied not only to a type in which the backrest and the seat body are synchronized, but also to a chair in which only the backrest tilts backward. In the case of a synchro-type chair, the second axis may be slid in the front-rear direction. The case may be fastened to the seat receiving body with fasteners such as rivets other than screws, or may be welded.

[Brief description of the drawings]

FIG. 1 is a right side view of a chair according to a first embodiment.

FIG. 2 is a plan sectional view taken along line II-II of FIG.

FIG. 3 is a sectional view taken along the line III-III of FIG. 2;

FIG. 4 is a sectional view taken along line IV-IV of FIGS. 2 and 5;

FIG. 5 is a plan sectional view of a resistance applying unit.

FIG. 6 is a sectional view taken along line VI-VI of FIGS. 2 and 5;

FIG. 7 is a partially cutaway front view of the cam.

FIG. 8 is a diagram showing a state in which resistance is applied.

FIG. 9 is a diagram showing an assembling procedure.

FIG. 10 is a diagram showing an assembling procedure.

FIG. 11 is a plan sectional view of a free state in the second embodiment.

FIG. 12 is a plan cross-sectional view illustrating a state where resistance is applied in the second embodiment.

FIG. 13 is a plan sectional view showing a third embodiment.

FIG. 14 is a plan sectional view showing a fourth embodiment.

FIG. 15 is a plan sectional view showing a fifth embodiment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 pillar 2 seat receiver 3 seat 4 backrest 7 first shaft 9 back support 12 coil spring 16 resistance applying means 17 movable plate 20 shaft 22 case 23 screw 24,25 collar 27 cam 32 lever

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Koichi Isoda 1-4-1 Imafukuhigashi, Joto-ku, Osaka City F-term in Itoki Crebio Co., Ltd. 3B091 AA04 AB03 AC05

Claims (2)

[Claims] 1. A seat and a backrest are mounted on a seat receiver provided at the upper end of a leg so that at least the backrest tilts backward, and the seat receiver moves in conjunction with the rearward tilt of the backrest. A chair provided with a resistance applying device provided with an appropriate number of movable plates and a friction plate for imparting resistance to the movement of the movable plate, wherein the movable plate and the friction plate are integrally incorporated in a case. A rocking structure for a chair, wherein the resistance applying means is unitized and the case is fixed to a seat receiving body. 2. The chair locking device according to claim 1, wherein said resistance applying means is set to be capable of applying frictional resistance to the movable plate at least in a state in which the backrest is allowed to tilt backward. Construction.