JPH10179315A - Structure for supporting back rest of chair - Google Patents

Abstract

PROBLEM TO BE SOLVED: To impart an accurate supporting state in accordance with the build and the liking of a person, in separating a chair back rest into a back supporting part and a waist supporting part and, at the time of their locking in projecting the waist supporting part forward relatively with the back supporting part. SOLUTION: This supporting structure is such that the tilting body 10 to which the back support 8 is attached and the seat support 5 are pivotally supported by the third axis 12, while the upper end of the first link 14 to which the waist support 9 is fixed is pivotally supported by the tilting body 10. The first link 14, tilting body 10 and the seat support 5 are interlocked with the second link 17, which is connected to the supporting frame 2 with the third link 25. The height of the second link 17 is adjustable, with the fifth axis 18 at the upper end of the second link 17 inserted in the slit-like pin hole 16 of the first link 14. By changing the height of the fifth axis 18, the initial posture of the waist support 9 can be adjusted, as can the extent of its relative movement against the back support 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a support structure for a backrest in a chair.

[0002]

2. Description of the Related Art In a chair, in which the backrest simply tilts backward, the support for the waist of the person is negligible at the time of rocking while leaning on the backrest.
In some cases, strain was placed on the lumbar spine and spinal cord. Therefore, the back of the chair is composed of a back support that supports the back of the person and a waist support that supports the waist (or the buttocks). It has been considered that the upper body is supported in a stable state during locking by protruding.

[0003] As a specific means, for example, Japanese Patent Application Laid-Open Nos. 7-95911, 7-95913, and 7-155233, which were filed by the applicant of the present application, disclose a method of fixing the upper end of a leg. Attach a guide member that extends diagonally upward and backward to the support frame that has been set up, and by using the guide action of this guide member, deform the waist support portion to extend in side view in conjunction with the backward tilt of the back support portion Is disclosed.

[0004] Similarly, Japanese Patent Application Laid-Open Nos. 7-163436 and 7-84741, which are filed by the applicant of the present invention, use an elastic member that deforms in conjunction with the backward tilt of the back support. hand,
It is disclosed that the waist support is projected forward.

[0005]

SUMMARY OF THE INVENTION However, Japanese Patent Application Laid-Open No. 7-959
No. 11, 7-95913, and 7-155233, in which the waist support is deformed using a guide member, it is necessary to use a waist for proper support of the body in a non-locking state. Since the supporting portion cannot be easily deformed, the deformation of the waist supporting portion at the time of locking acts as a resistance against the backward tilting of the backrest, and therefore, it may be difficult to smoothly tilt the back supporting portion and the waist supporting portion backward during the locking. there were.

Further, Japanese Patent Application Laid-Open Nos. 7-163436 and 7-18
In the method in which the waist support is pushed out using an elastic member as disclosed in Japanese Patent No. 4741, the elastic force of the elastic member is hardly deformed in order to prevent the elastic member from returning due to the reaction force of the body at the time of locking. This would impede the smooth back tilting of the back,
Smooth tilting of the backrest and proper support of the body conflicted.

According to the present invention, when the backrest is formed in the back support portion and the waist support portion and these are moved relative to each other at the time of locking, the backrest can be smoothly tilted without impairing the function of supporting the waist by the waist support portion. It is an object of the present invention to enable the user to change the supporting state of the upper body at the time of locking according to the physique and preference of a person.

[0008]

In order to achieve this object, the present invention provides a seat back attached to a support frame provided at the upper end of a leg and a backrest that tilts rearward against elastic support means such as a spring. The backrest comprises a back support for supporting a person's back and a waist support for supporting a person's waist, and the back support and the waist support are separated or bent separately. In a chair which is freely connected, the back support is attached to a tilting body pivotally attached to the seat body or the support frame so as to be tiltable rearward, and the back support is fixed to the tilting body or the back support to the waist support. One link is pivotally mounted so as to be able to rotate in the front-rear direction about its upper end, and the tilting body and the first
The link is connected to the tilting body and the first link by a second link rotatably connected to the tilting body and the first link. Further, the support frame and the second link are rotatably connected to the support frame and the second link. The third link is pivotally connected to the first link, and the third link suppresses the rotation of the second link, so that the first link is relatively forward centered on the upper end thereof in conjunction with the backward tilting of the tilting body. Set to rotate ".

[0009]

Next, embodiments of the present invention will be described with reference to the drawings. 1 to 9 show a first embodiment, in which FIG. 1 is a longitudinal side view of a chair, FIGS. 2 to 4 are separated views of members, FIG. 5 is a cross-sectional view taken along VV of FIG. Is in FIG.
VI-VI sectional view, FIG. 7 is VII-VII sectional view of FIG. 1, FIG.
Is an enlarged view of a main part, and FIG. 9 is a view showing a locking state. This chair includes a leg 1, a support frame 2 fixed to the upper end of the leg 1, a cushioned seat 3 attached to the support frame 2, and a cushioned backrest 4. It is fixed to the seat receiver 5.

As shown in FIGS. 5 to 7, the support frame 2 is formed in an open U-shape in front view. On the other hand,
As shown in FIGS. 1 and 5, the seat receiver 5 is located inside the left and right side plates 2 a of the support frame 2 when viewed from the front, and the side plate of the seat receiver 5 is connected to the front end of the side plate 2 a of the support frame 2. Are pivotally connected by a horizontal first shaft 6. In this case, the first pivotal support hole 7 formed in the side plate 2a of the support frame 2 for fitting the first shaft 6 is formed in a downwardly concave circular arc hole in a side view. Accordingly, the seat body 3 can retreat while tilting rearward.

The backrest 4 is divided into a back support 8 for supporting a person's back and a waist support 9 for supporting a person's waist, and the back support 8 is tilted substantially in an L-shape in side view. Body 10
(See also FIG. 3). The front end of the tilting body 10 is pivotally connected to the side plate 2a of the support frame 2 by a second shaft 11. Further, a portion of the tilting body 10 located slightly behind the front end is pivotally connected to the seat receiving body 5 by a third shaft 12.

Therefore, when a person leans on the backrest 4, the tilting body 10 tilts backward about the second shaft 11, and in conjunction with this, the seat 3 is guided by the first pivot hole 7 and retreats. It will tilt backward while moving. The waist support 9 is the first
It is fixed to the link 14. The first link 14 is the waist support 9
Projecting upwards, and the upward projection 14
a is pivotally connected to the upper part of the tilting body 10 by a fourth shaft 15.
In this case, by forming the upwardly projecting portion 14a of the first link 14 in a forwardly concave shape when viewed from the side, the lower end of the back support 8 is fitted into the upwardly projecting portion 14a. In other words, the fourth shaft 15 can be arranged above the lower end of the back support 8 with the relative rotation between the back support 8 and the waist support 9 allowed. In addition, the first link
The upper end of 14 may be pivotally attached to a bracket projecting from the back support 8.

The first link 14 is provided with a pin hole 16 which extends long in a slightly backwardly inclined posture in a side view in a side view.
The upper end of a second link 17 formed into a U-shape in side view is slidably and rotatably engaged with a fifth shaft 18 via the pin hole 16. The lower end of the second link 17 is the third shaft
12 pivotally attaches to the tilting body 10 and the seat receiver 5.

As shown in FIGS. 4 and 8, the upper portion 17a of the second link 17 is separated from the lower portion, and the attachment plate 19 is fastened to both of them by screws 20. In this case, the height of the upper portion 17a of the second link 17 can be adjusted steplessly by forming the screw insertion hole of the attachment plate 19 in the elongated hole 21 extending vertically. In other words, the fourth axis 15 and the fifth axis 18
Can be adjusted.

Also, as shown in FIG.
22 and the extension line 23 of the pin hole 16 in the first link 14 are set to intersect at a slight angle θ. That is, the extension 23 of the pin hole 16 is set to be inclined backward relative to the extension 22 of the elongated hole 21. Accordingly, when the height of the second link 17 is adjusted to move the fifth shaft 18 upward, the waist support 9 moves so as to protrude forward, and the initial posture of the waist support 9 is changed.

The extension 23 of the pin hole 16 and the extension 22 of the slot 21 may be parallel or the extension 23 of the pin hole 16 may be parallel to the slot 21.
May be set to be inclined forward with respect to the extension line 22 of. A third link 25 is disposed between a portion of the lower portion of the second link 17 behind the leading end and the support frame 2. It is pivotally connected by a shaft 26 and a seventh shaft 27.

Although not shown, the rearward tilt of the backrest 4 and the rearward tilt of the seat body 3 are elastically supported by elastic support means such as a spring. In this case, the backrest 4 and the seat body 3 may be supported by separate elastic support means, or may be supported by one elastic support means. The elastic support means is set to have a spring force that does not deform when the user merely sits on the chair, but deforms when a large moment is generated by leaning on the backrest 4.

In FIG. 9, the second link 17 is shown in an integrated state, and the state in which the height can be adjusted by the attachment plate 19 is omitted. In the above configuration, as shown in FIG. 9, when a person leans on the backrest 4, the back support portion 8 tilts rearward, and in conjunction with this, the seat body 3 is also guided into the first pivot hole 7 of the support frame 2. It is tilted backward while being retreated. Then, the second link 17 is in a state of stretching against the third link 25, and the rearward tilting of the third link 25 is suppressed.
And the tilting body 10 rotates forward.

In this case, the fifth shaft 18 moves upward in the pin hole 16 and the lower portion of the back support 8 enters the upwardly projecting portion 14a of the first link 14, whereby the first link 14 Is allowed to rotate forward with respect to the tilting body 10, and as a result, the waist support 9 projects relatively forward with respect to the back support 8. As a result, the waist of the person is properly supported by the waist support 9, and a comfortable locking state can be obtained.

The rotation of the second link 17 corresponds to the rotation of the third link 25.
Therefore, the waist support 9 can be relatively moved relative to the back support 8 while the back support 8 and the waist support 9 are tilted backward as a whole. By adjusting the height of the second link 17, the initial posture of the waist support 9 and the degree of relative projection with respect to the back support 8 can be changed. That is, as shown by a dashed line in FIG. 8, when the height of the upper end of the second link 17 is increased, the extension 23 of the pin hole 16 and the extension 22 of the elongated hole 21 intersect at an angle θ. Due to this, the waist support 9 protrudes forward in the initial state with no load, and the distance L between the fourth shaft 15 and the fifth shaft 18 is reduced, so that the waist support 9 is supported by the back. The angle of forward tilt relative to the portion 8 becomes large.

Therefore, by adjusting the height of the fifth shaft 18, the locking state can be adjusted according to the physique and preference. Instead of drilling the elongated holes 21 in the attachment plate 19, a plurality of round holes into which the screws 20 are fitted are drilled at appropriate intervals in the vertical direction, so that the height of the fifth shaft 18 is appropriately adjusted. Other adjustment modes such as a stepwise adjustment at an appropriate pitch may be used.

FIGS. 10 to 11 show a second embodiment. FIG. 10 is a vertical side view, and FIG. 11 is a vertical side view in a locking state. This embodiment is also basically the same as the first embodiment. The difference from the first embodiment is that the seat receiver 5
And the front portion of the support frame 2 are connected by a fourth link 30 pivotally connected via a first shaft 6 and an eighth shaft 29 so as to be able to retreat and tilt backward. The point that the first link 14 is formed in an L-shape when viewed from the side is that the upper end of the first link 14 is pivotally connected to the lower end of the back support 8 of the tilting body 10 with the fourth shaft 15.

Although not shown, the backrest 4 and the seat 3
Elastic support means for elastically supporting the rearward tilting. Further, the tilt range of the backrest 4 and the seat body 3 is regulated by a suitable stopper means. In this embodiment, the second link 17 is displayed in an unadjustable integrated state.
It goes without saying that the height of the shaft 18 may be adjusted steplessly or stepwise.

When the upward projecting portion 14a of the first link 14 is formed in a forwardly concave shape as viewed from the side as in the first embodiment, the relative rotation between the back support portion 8 and the waist support portion 9 is controlled. In the allowed state, the fourth shaft 15 can be arranged above the lower end of the back support 8, so that the waist support 9 is
, The degree of protruding greatly can be increased, and the function of supporting the waist can be made more reliable.

This can also be achieved by the structure of the reference example shown in FIGS. This point will be described. 12 is a longitudinal side view, FIG. 13 is a sectional view taken along XIII-XIII in FIG. 12, and FIG.
15 is a side view in the locking state. FIG. 15 is a side view in a locking state. This is the same as the embodiment. Also, a first link having the same shape as that of the first embodiment.
It is the same as that of the first embodiment, which is provided with 14 and is pivotally connected to the upper part of the tilting body 10 by the fourth shaft 15.

On the other hand, the first embodiment is different from the first embodiment in that the first link 14 and the support frame 2 are connected to each other via a fifth link 32 which is pivotally connected to the first frame 14 and a ninth axis 31. The points are different. Also in this example, as shown in FIG.
As in the embodiment, the waist support portion 9 can be largely projected forward with respect to the back support portion 8.

In this example, as shown in FIG.
The seat receiver 5 may be connected to the support frame 2 via the link 30.

[0028]

As described above, according to the present invention, when a person leans on the backrest 4, the first to third links rotate reliably in conjunction with the backward tilting of the tilting body. It can be ensured that the hip support projects forward relative to the back support. Further, since the waist support is fixed to the first link, the waist support does not deform due to the reaction force of the person's waist. Therefore, the upper body of the person in the rocking state can be stably placed in a stable state. Can support.

Then, the second link is stretched by the third link, and the rotation of the first link is suppressed, so that the waist support portion protrudes forward relative to the back support portion. From this, it is possible to make the waist support relatively project forward relative to the back support while the back support and the waist support move together.
As a result, it is possible to more surely fit the backrest 4 to the upper body of the person in the rocking state.

Further, according to the second aspect of the present invention, it is possible to prevent the gap between the seat body and the backrest from becoming too wide, and to obtain a more comfortable locking state. Further, according to the present invention, by adjusting the height of the second link, the initial posture of the waist support and the degree of the waist support protruding forward relative to the back support are adjusted. Since it is possible, there is an advantage that the support state by the backrest can be changed according to the physique and preference of the person.

[Brief description of the drawings]

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

FIG. 2 is a separate side view of a support frame and a seat body.

FIG. 3 is a separated side view of each link.

FIG. 4 is a perspective view of a second link.

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

FIG. 6 is a sectional view taken along line VI-VI of FIG.

FIG. 7 is a sectional view taken along the line VII-VII of FIG. 1;

FIG. 8 is a vertical sectional side view of a main part.

FIG. 9 is a diagram showing a locking state.

FIG. 10 is a longitudinal side view of a chair according to a second embodiment.

FIG. 11 is a diagram illustrating a locking state of FIG. 10;

FIG. 12 is a longitudinal sectional side view of a reference example.

13 is a sectional view taken along the line XIII-XIII of FIG.

FIG. 14 is a rear view as viewed from XIV-XIV in FIG. 12;

FIG. 15 is a side view showing a locking state of the reference example.

FIG. 16 is a diagram showing a modification of the reference example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Leg 2 Support frame 3 Seat 4 Backrest 5 Seat support 8 Back support 9 Waist support 10 Tilt body 14 1st link 15 5th axis 17 2nd link 18 Pin hole 22 Elongated hole 25 3rd link

Claims (3)

[Claims] 1. A seat body 3 attached to a support frame 2 provided at the upper end of a leg 1, and a backrest 4 that tilts backward against elastic support means such as a spring. It is composed of a back support 8 for supporting the back and a waist support 9 for supporting the waist of a person, and these back support 8 and the waist support 9 are separated from each other or connected to bend freely. In the chair, the back support portion 8 is attached to a tilting member 10 pivotally attached to the seat body 3 or the support frame 2 so as to be tiltable rearward, and is fixed to the tilting member 10 or the back support portion 8 to the waist support portion 9. First link
14 is pivotally mounted on the upper end thereof so as to be pivotable in the front-rear direction, and the tilting body 10 and the first link 14 are rotatably pivoted on the tilting body 10 and the first link 14. The support frame 2 is connected to the support frame 2 by a second link 17 attached thereto.
17 are connected to each other by a third link 25 pivotally connected to the support frame 2 and the second link 17, and the third link 25 suppresses the rotation of the second link 17.
10, the first link 14 is set so as to rotate relatively forward around the upper end thereof in conjunction with the backward tilting of 10;
A support structure for a backrest in a chair, characterized in that: 2. The seat according to claim 1, wherein said seat is attached to said support frame so as to be tiltable rearward.
A backrest supporting structure for a chair, wherein the tilting body 10 and the tilting body 10 are linked so that when the tilting body 10 tilts backward, the seat body 3 tilts rearward. [Claim 3] In claim 1 or claim 2,
A support structure for a backrest in a chair, wherein a height of an upper end of the second link 17 can be adjusted to be attached to the first link 14.