JP2000333760A - Chair rocking structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To slowly tilt a back rest backward, and improve the amenity at the time of a rocking by adding a backward tilt retarding means which imparts a forcible frictional resistance to the movement of a movable member to tilt the back rest backward, on a chair wherein the back rest tilts backward by resisting a spring means. SOLUTION: When a seated person leans to a back rest 5, the back rest 5 tilts backward by resisting a coil spring 16. At the same time, a seat body 3 tilts backward as well by resisting the coil spring 16 while retreating. In this case, a large frictional resistance is generated between a frictional protuberance 10 and a flange 2a in a block 7 and also between a slot 10 of the block 7 and a first shaft 8, and the back rest 5 slowly tilts backward compared with a case where the frictional protuberance 10 does not exist. That is, a hysteresis loss effect or a damper effect can be imparted to the backward tilt of the back rest 5, and a comfortable backward tilting feeling can be obtained. Also, in this embodiment, a pair of right and left blocks 7 can be simply provided to obtain the above effect.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a locking structure for an office chair or the like.

[0002]

2. Description of the Related Art A chair provided with a rocking function has a structure in which the rearward tilt of a backrest is supported by a spring means such as a coil spring, and a type in which only the backrest tilts rearward.
The seat also retreats and / or interlocks with the back tilt of the backrest.
There is a synchro type that tilts backward.

[0003]

By the way, when a seated person leans against a backrest, the person tends to feel as if the back is softly supported when the backrest slowly leans backward. .

However, in the conventional chair, the backrest merely tilts backward against the spring means, so that the backward tilting speed of the backrest is determined by the relationship between the spring force of the spring means and the load of a person on the backrest. Not just. Therefore, if the spring force of the spring means is weak, the backrest will tilt backwards in a very short time in the sense of a stomach, and as a result, the back will feel as if it is impacted, and a comfortable locking state will be obtained. I couldn't do that.

[0005] In particular, since the upper body of the person slides rearward as the backrest tilt angle increases, the degree of the moment acting on the backrest tends to increase more than the backrest tilts. However, the backrest instantly leans backward, so the feeling is not good.

[0006] In this regard, it is considered that it is sufficient to increase the spring force of the spring means. However, simply increasing the spring force of the spring means only makes it difficult for the backrest to tilt backward. No. That is, it is necessary to gradually tilt the backrest backward without excessively increasing the reaction force against the human back, and this cannot be determined by merely adjusting the spring force.

The object of the present invention is to improve such a situation.

[0008]

SUMMARY OF THE INVENTION The present invention is a chair provided with a seat body and a backrest, wherein at least the backrest tilts backward against spring means, and a movable member for tilting the backrest backward. The present invention is characterized in that there is provided a rearward tilting hardening means for imparting forcible frictional resistance to the vehicle.

Further, according to the present invention, the seat is attached to the seat receiver provided at the upper end of the leg so that the seat can be tilted and retracted by the first shaft, and the backrest can be attached. In a synchro-type chair in which a back support arm is attached by a second shaft so as to be tiltable rearward and these seats and the back support arm are connected by a third shaft so as to interlock with each other, the seat support and / or the seat body Also, the present invention includes a configuration in which a friction member is provided as the rearward tilting hardening means, which imparts forcible resistance to relative movement between the first shaft and the seat receiver or the seat body.

[0010]

According to the present invention, when a seated person leans against the backrest, the backrest tilts backward against the spring means. However, since the tilting is suppressed by the backward tilting disabling means (in other words, (A hysteresis loss effect or a damper effect is given to the backward tilt of the backrest), and the backrest can be slowly tilted backward without excessively increasing the spring force of the spring means. Comfort can be greatly improved.

[0011]

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

1st Embodiment (FIGS. 1 to 9) FIGS. 1 to 9A show a first embodiment, of which FIG.
2 is a right side view of the chair, FIG. 2 is a plan view in a partially omitted state, FIG. 3 is a sectional view taken along the line III-III of FIG. 2, and FIG.
FIG. 5 is a sectional view taken along line VV of FIG. 1, FIG. 6 is a separated front view of essential parts, and FIG. 7 is a sectional view taken along AA, BB, and C of FIG.
FIG. 8A is a diagram showing the operation when viewed from the direction of −C.

The chair includes a leg (gas cylinder) 1 covered with a cover, a seat 2 fixed to the upper end of the leg 1, a seat 3 and a back support arm 4 attached to the seat 2; And a backrest 5 attached to the back support arm 4. The seat receiver 2 is formed in a box shape opened upward, and as shown in FIGS. 2 to 4 and the like, an outwardly extending flange 2 a is integrally formed on an opening edge of a front half portion of the seat receiver 2. It is provided in.

A base bracket 6 having an open U-shape facing downward as viewed from the front is fixed to the lower surface of the seat 3, and a pair of side plates 6 located outside the seat receiver 2 are attached to the base bracket 6.
a is provided. A block 7 made of a member having a large coefficient of friction, such as a synthetic resin, is fixed to the base bracket 6 as an example of the backward tilting preventing means and a friction member described in the claims by screws or the like. A first shaft 8 extending in the left-right direction extending in the horizontal direction is made to pass through the seat receiver 2. The first shaft 8 is fixed to the flange 2a of the seat receiver 2 by welding.

In this case, the insertion hole of the first shaft 8 in the seat receiving body 2 is a simple round hole, while the insertion hole of the first shaft 8 in the side plate 6a of the base bracket 6 and the block 7 is gently inclined backward in side view. The inclined oblong hole 9 is set. Therefore, the seat body 3 can tilt backward while moving backward.

At the front of the block 7, a friction projection 10 is provided integrally with the flange 2a of the seat receiving member 2 to contact from below. The friction protrusion 10 is fitted into a hole 11 formed in the side plate 6a of the base bracket 6,
In addition, the side plate 6a of the base bracket 6 has
0 is provided integrally with the inward horizontal piece 6b.

A substantially front portion of the back support arm 4 is made of a metal plate and has an open U-shaped cross section and is formed in a V-shape in each side view. A rear bracket 12 having a side plate extending downward is fixed to the outside of the seat receiving body 2.
The front end of the side plate 4 a of the back support arm 4 is attached to the second shaft 13 so as to be tiltable rearward. The side plate 4a of the back support arm 4 and the rear part of the side plate 6a of the base bracket 6 are rotatably connected by a third shaft 14.

Accordingly, when the backrest 5 tilts rearward about the second shaft 13, the seat body 3 tilts rearward while retreating by the guide action of the elongated hole 9 in which the first shaft 8 is fitted. When the seat 3 is retracted and tilted backward, the friction projections 10 of the block 7 are set so as to keep in contact with the flange 2a of the seat receiver 2 with strong friction. In other words, the friction projection 10 is set so as to be twisted between the first shaft 8 and the elongated hole 9 of the block 7 so that the friction projection 10 comes into contact with the flange 2a with a strong frictional force.

The rear plate 2c of the seat receiver 2 is formed to be inclined in side view so as to overlap the inclined portion of the back support arm 4 from the front, and as shown in FIG. 3 and FIG. 2, a bolt 15 is inserted through the rear plate 2 c and the back support arm 4 from the inside to the outside of the seat receiver 2.
In addition, a coil spring 16 as an example of a spring means is fitted, and a photographing 17 is screwed in. The bolt 15 is provided with a bar 15a for retaining the bar 15a.
Into the bearing 18 extending in the left-right direction,
The bolt 14 is held so as not to rotate. Further, the bolt 14 can be largely turned downward so that the back support arm 4 is allowed to tilt backward.

In the above configuration, when a seated person leans against the backrest 5, the backrest 5 tilts backward against the coil spring 16 and the seat body 3 also moves backward while retracting against the coil spring 16. To tilt. In this case, the presence of the friction projections 10 in the block 7 causes a large frictional resistance between the friction projections 10 and the flange 2 a and between the elongated hole 10 of the block 7 and the first shaft 8. 5 tilts backward more slowly than when the friction projection 10 is not present. That is, a hysteresis-loss effect or a damper effect can be given to the backward tilt of the backrest 5. Therefore, a comfortable backward tilt feeling can be obtained.

In the present embodiment, since the backward tilting speed of the backrest 5 is suppressed by using the seat receiver 2, it is only necessary to provide a pair of left and right blocks 7, so that the structure becomes complicated and the member management becomes difficult. There is an advantage that a hysteresis loss effect can be imparted without taking unnecessary time and effort.

In this embodiment, since the rear tilting of the back support arm 4 is supported by the spring 16, the base bracket 6 can be removed and the seat 3 can be directly attached to the seat receiver 2. Therefore, it is possible to switch between a type in which only the backrest 5 tilts backward and a type in which the backrest 5 and the seat body 3 synchronize with each other in a state where the members are shared (only the backrest 5 is rearward). In the case of a tilting type, it is necessary to adopt a configuration different from that of the present embodiment in order to obtain a hysteresis loss effect.)

{Modification} FIGS. 1 and 8 show examples.
As can be easily understood from (A), if the seat body 3 is tilted excessively backward, a phenomenon in which a human thigh is pushed up at the front portion of the seat body 3 occurs, which is not preferable. On the other hand, in order to extend the body as much as possible in the rocking state so that the body can be relaxed, the back support arm 4 and the backrest 5 need to have a large rearward inclination angle, so that the rear portion of the seat body 3 sinks greatly, The backward inclination angle of the seat body 3 also increases.

In this regard, as shown in FIG. 8 (B), when at least a portion of the flange 2a of the seat receiving body 2 which is in contact with the friction projection 10 is inclined backward in a side view, the friction projection 10 is flanged. Since the front portion of the seat body 3 can be moved downward in conjunction with the rearward tilting of the backrest 5 while maintaining the state of contact with the backrest 2a (that is, the tilt angle of the elongated hole 9 can be increased). Therefore, there is an advantage that the back tilt angle of the backrest 5 can be increased without increasing the tilt angle of the seat body 3.

Second Embodiment (FIGS. 9 to 12) FIGS.
12 shows a second embodiment, FIG. 9 is a right side view of a chair, FIG. 10 is a side view of a partially broken groove of a main part, and FIG.
9A is a partial sectional view taken along line AA of FIG. 9, FIG. 11B is a partial sectional view taken along line BB of FIG. 9, and FIG.

The basic components of this embodiment are the same as those of the first embodiment, and a description of common parts will be omitted.
In this embodiment, as an example of a friction member, a bush 19 made of a synthetic resin having a large friction coefficient is fixed to an outer surface of a front portion of the seat body 2 by an appropriate means such as screwing. By providing the body 2 with an elongated hole 9 in which the first shaft 8 slides back and forth in the horizontal direction,
The seat body 3 is allowed to interlock with the backrest 5.

Further, a recess 20 which is inclined rearward in a side view is formed in a portion of the seat body 3 slightly behind the bush 19,
As an example of the friction member described in the claims, a friction slider 21 made of a synthetic resin having a large frictional resistance is screwed onto the inner surface of the side plate 6a of the base bracket 6 in the seat body 3.
The friction slider 21 is brought into contact with the recess 20 of the seat receiver 2 from above. The first
The shaft 8 has a sharpened tip for facilitating insertion into the bush 19 and the like, and is prevented from falling off by an outer member (cover) C indicated by a chain line.

In this embodiment, as shown in FIG. 12, when the seated person leans on the backrest 5, the seat 3 is moved backward by the first shaft 8 along the elongated hole 9, so that the backrest is moved. In conjunction with 5, it tilts backward while retreating. Then, a large frictional resistance is generated between the friction slider 21 and the seat receiving body 2 and between the first shaft 8 and the bush 19, so that a rapid retreat of the seating body 3 is suppressed, so that the hysteresis. The loss effect is exhibited.

The oblong hole 9 may be inclined so as to incline backward in a side view. In this case, the inclination angle of the recess 20 in the seat receiver 2 is larger than the oblique angle of the oblong hole 9. Just do it.

Third Embodiment (FIGS. 13 to 18) FIG.
3 to 18 show the third embodiment, FIG. 13 is a side view of a main part, FIG. 14 (A) is a cross-sectional view taken along the line XIVA-XIVA of FIG. 13, and FIG. 14 (B) is a separation plane of the main part. FIG. 15, FIG. 15 is an isolated side view, FIG. 16 is an XVIA-XIVA view of FIG.
18 is a partially cutaway side view during assembly, FIG. 18A is a cross-sectional view taken along the line AA of FIG. 17, and FIG.

In the third embodiment, the movement of the seat body 3 is basically the same as that of the second embodiment, and the first shaft 8 slides in the elongated holes 9a and 9b of the bush 19, so that the backrest 5 and the backrest 5 are moved. Interlocking with the seat 3 is allowed. Although not shown in the drawing, it goes without saying that the backrest 5, the back support arm 4, and the coil spring 16 are provided.

This embodiment does not include the friction slider 21 as in the second embodiment. Instead, the bush 19 is provided with a first member 19a located inside the seat receiver 2.
And a second member 19b located outside the seat receiver 2, and a bridge portion 19c connecting the two members 19a, 19b at both front and rear ends. Seat support 2
The side plate is formed with a slit 9c into which the bridge portion 19c fits exactly. Although not shown,
The bush 19 is immovably attached to the seat receiver 2 by an appropriate fixing means such as a screw or an engaging means including an engaging claw and an engaging hole.

Elongated holes 9a, 9b into which the first shaft 8 is slidably fitted are formed in both members 19a, 19b of the bush 19, as shown in FIGS. 16 to 18 (A). Before the one shaft 8 is inserted, the first member 19a
And the second member 19b are displaced vertically opposite sides of the center line 23 of the elongated hole 9c of the seat receiver 2. For this reason, the long holes 9a, 9b of both members 19a, 19b are vertically displaced in steps. Then, when the first shaft 8 is inserted into both the long holes 9a, 9b, both members 19a, 19b are pushed and bent by the first shaft 8, and as shown in FIG. It is bent and deformed like a bow.

As described above, both members 19 of the bush 19
Since a and 19b are bent and deformed by the first shaft 8,
In other words, since the first shaft 8 is inserted in a state where both members 19a and 19b are bent and deformed, the first shaft 8 is held from above and below by the elastic restoring force of both members 19a and 19b of the bush 19. And the first shaft 8
The bush 19 provides frictional resistance to the backward movement of the backrest 5 so that the backward movement of the backrest 5 causes a hysteresis.
Gives a loss effect.

According to the third embodiment, since only the right and left bushes 19 need be provided, there is an advantage that the number of members can be reduced while an appropriate hysteresis loss effect can be exhibited. Note that only one of the two members 19a and 19b of the bush 19 may be elastically deformed. Further, the elastic force of the bush 19 may be set to increase as the first shaft 8 moves backward.

{Others} The present invention can be variously embodied in addition to the above embodiments. For example, as the means for making it difficult to tilt backward, various types of principles can be adopted, such as using a variable condenser type in which an appropriate number of friction plates are stacked, or using an air damper or a hydraulic damper.

The form, operation principle, and installation location of the backward tilt preventing means such as a friction member are not particularly limited. However,
With respect to the installation location, the function of suppressing the rearward tilt of the backrest 5 becomes stronger as the distance from the rotation support point of the backrest increases as the distance from the rotation fulcrum of the backrest increases. Seat 3 or seat receiver 2
When a configuration is adopted in which forcible frictional resistance is applied to the relative movement of the backrest, there is an advantage that the rearward tilting of the backrest can be accurately suppressed.

Needless to say, the present invention can be applied to a chair in which only the backrest tilts backward. In the case of a synchro-type chair, a structure in which the second shaft slides may be used.

The means for preventing backward tilt described in the claims can be rephrased as hysteresis / loss applying means (device) or damper means (device).

[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 view in a state where a seat body is omitted.

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 FIG. 2;

FIG. 5 is a sectional view taken along line VV of FIG. 1;

FIG. 6 is an isolated front view of a main part.

FIG. 7 is a diagram viewed from the direction of AA, BB, and CC in FIG. 7;

8A is a diagram showing an operation, and FIG. 8B is a diagram showing a modification.

FIG. 9 is a right side view of the chair according to the second embodiment.

FIG. 10 is a side view of a partially broken groove of a main part.

11A is a partial cross-sectional view taken along the line AA in FIG. 9, and FIG.
FIG.

FIG. 12 is a diagram illustrating an operation.

FIG. 13 is a side view of a main part of a chair according to a third embodiment.

14A is a cross-sectional view taken along the line XIVA-XIVA of FIG. 13, and FIG. 14B is a separated plan view of a main part.

FIG. 15 is a separated side view.

FIG. 16 is an XVIA-XIVA view of FIG. 14 (B).

FIG. 17 is a partially cutaway side view in a state before the first shaft is inserted.

18A is a cross-sectional view taken along the line AA in FIG. 17, and FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Leg 2 Seat receiving body 2a Flange 3 Seat 4 Back support arm 5 Backrest 6 Base bracket 7 Block 8 First shaft 9 Long hole 10 Friction protrusion 13 Second shaft 14 Third shaft 16 Coil spring 19 Bush 20 Depression 21 Friction slider

Claims (2)

[Claims] 1. A chair having a seat body and a backrest, wherein at least the backrest tilts backward against spring means, forcibly imparting frictional resistance to the movement of the movable member for tilting the backrest backward. A rocking structure for a chair, comprising: means for making it difficult to tilt backward. 2. A seat support provided on the upper end of a leg so that the seat can be tilted backward and backward by a first shaft, and a back support arm to which a backrest is attached is mounted so as to be tiltable rearward by a second shaft. The seat body and the back support arm are connected to each other by a third shaft so as to interlock with each other, and further, the seat shaft and / or the seat body are connected to the first shaft as an example of the backward tilt disabling means. The rocking structure for a chair according to claim 1, further comprising a friction member for imparting forcible resistance to relative movement with the seat receiver or the seat body.