JP2003250651A - Chair - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a chair capable of tilting a support for the back and a support for a region below the back with both supports interlocking with each other, and of pulling in or protruding a waist part support member more than a support member for the back when tilting. <P>SOLUTION: This chair has the back member (the support for the back) 3 and the waist part support member (the support for the region below the back) 4 by attaching a seat plate 2 to a seat receive member 1 so as to swing. The chair is provided with a first link 5 attached to the seat receive member 1 so as to swing and a second link 6 attached to the seat plate 2 so as to swing. The back member 3 is attached to either of the first link 5 and the second link 6, and the waist part support member 4 is attached to the other of them. The first link 5 and the second link 6 are mutually connected so as to swing, and the waist part support member 4 is tilted by an amount different from an inclination amount of the back member 3 in the interlocking relationship with inclination of the back member 3. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a chair. More specifically, the present invention relates to a chair having a back support and a lower back region support, which can be reclined.

[0002]

2. Description of the Related Art Conventionally, there is a chair having a waist support member that supports the waist separately from a tiltable backrest member. For example, Japanese Utility Model Application Laid-Open No. 57-50251 discloses a chair that moves a shiatsu portion (waist support member), which is not a member that merely supports the lumbar region, for the purpose of acupressure of the lumbar region in conjunction with tilting of the backrest member. ing.

This chair is shown in FIG. Shiatsu part 1 at the top
01 is attached to the lever 1 so that the lever 102 can swing.
03, and the lower end of the lever 102 is connected to the support pipe 104. The support pipe 104 supports the backrest member 105, the lower end of which is the seat portion 1.
03 is swingably connected. When the seated person leans against the backrest member 105, the support pipe 104 tilts to lower the lower end of the lever 102. Therefore, the lever 102 swings to move the acupressure part 101 forward, and acupressure the waist of the seated person.

[0004]

However, in the above-mentioned chair, when the backrest member 105 is tilted rearward, the acupressure part 101 always moves forward, and the acupressure part 101 can be reclined together with the backrest member 105. Can not. Therefore, the above mechanism cannot be directly applied to a normal chair having a lumbar support member instead of the acupressure part 101. Further, since the work performed by the seated person differs depending on whether the backrest member 105 and the lumbar support member are reclined or not, the backrest member 105 is not only operated in conjunction with each other.
It is necessary to interlock while changing the positional relationship between the lumbar support member and.

According to the present invention, a back support such as a backrest member and a lower back region support such as a lumbar support member can be tilted in conjunction with each other, and the lower back region support is retracted or protruded from the back support when tilted. The purpose is to provide a chair that can be used.

[0006]

In order to achieve the above object, the invention according to claim 1 is such that a seat plate is swingably attached to a seat receiving member, and a seat having a back support and a lower back region support is provided. A first link swingably attached to the receiving member and a second link swingably attached to the seat plate.
And a back support is attached to either one of the first link and the second link and a lower back region support is attached to the other, and the first link and the second link can be rocked. The lower back region support is connected and tilted by an amount different from the tilting amount of the back support in association with the tilting of the back support and the seat plate.

Therefore, when the seated person leans against the back support and tilts it, the lower back region support also tilts in conjunction with this. Since the back support and the lower back region support have different tilting amounts, for example, when the lower back region support tilts more, the lower back region support can be retracted with respect to the back support for reclining. Further, when the back support tilts more, the reclining can be performed by projecting the lower back region support with respect to the back support.

Further, in the chair according to the second aspect, the first link is constituted by the back support rod. Therefore, it is not necessary to provide the first link as a new component,
Therefore, the increase in the number of parts can be suppressed and the increase in the manufacturing cost can be suppressed.

In the chair according to the third aspect, the back support is attached to the first link and the lower back area support is attached to the second link, respectively, and the lower back area support is linked to the tilt of the back support. It tilts more than. Therefore, it is possible to recline by retracting the lower back region support with respect to the back support.

[0010]

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 4 show an example of an embodiment of a chair to which the present invention is applied. In this chair, a seat plate 2 is swingably attached to a seat receiving member 1, and a backrest member 3 as a back support and a lumbar support member 4 as a lower back region support are provided. A first link 5 movably attached and a second link 6 swingably attached to the seat plate 2, and a backrest member for either one of the first link 5 and the second link 6. 3, the waist support member 4 is attached to the other, and the first link 5 and the second link 6 are swingably connected to each other, and the waist support is interlocked with the tilting of the backrest member 3 and the seat plate 2. The member 4 is tilted by an amount X2 different from the tilt amount X1 of the backrest member 3. In the present embodiment, the first link 5 is composed of a back support rod (hereinafter referred to as the back support rod 5), the back support member 3 is attached to the back support rod 5, and the waist support member 4 is attached to the second link 6. The waist support member 4 is tilted to a greater extent (X1 <X2) than the backrest member 3 in association with the mounting and tilting of the backrest member 3 and the seat plate 2. Further, the back support is the backrest member 3 and the lower back region support is the waist support member 4, so that the back support 3 and the lower back region support 4 are configured as separate members.

A front portion of the seat plate 2 is swingably attached to the seat receiving member 1 fixed to the column 7 by a connecting pin 23. The lower end of the back support rod 5 is swingably attached to the center of the seat receiving member 1 by a connecting pin 18. An elastic member, for example, a compression coil spring 8 is provided in a compressed state between the front portion of the seat receiving member 1 and the lower end of the back support rod 5, and always urges the back support rod 5 in a standing direction. . In the vicinity of the lower end of the back support rod 5, there is a long hole 9 that allows the back support rod 5 to swing within a certain range around the connecting pin 18
Is provided and is fixed to the seat receiving member 1.
By penetrating 0 into the long hole 9, the tiltable angle of the back support rod 5 is limited to the range in which the shaft 10 can relatively move in the long hole 9. A gas spring 11 with a lock mechanism is provided between the rear end of the seat receiving member 1 and the center of the back support rod 5. The gas spring 11 is connected to the rear end portion of the seat receiving member 1 by a connecting pin 19 and to the central portion of the back support rod 5 by a connecting pin 20, respectively. The gas spring 11 constitutes a triangular link mechanism together with the seat receiving member 1 and the back support rod 5, and when the length of the gas spring 11 can be changed, the back support rod 5 can be tilted. When the length of the spring 11 is fixed, the back support rod 5 cannot be tilted. That is, the gas spring 11
The angle between the backrest member 3 and the waist support member 4 can be locked by fixing the length. The length of the gas spring 11 is fixed and the gas spring 11 is released by operating a lever (not shown).

A connecting arm 5a is provided near the upper end of the back support rod 5, and the tip of the connecting arm 5a is swingably connected to the second link 6 by a connecting pin 21.
That is, the connecting arm 5a connects the first link 5 and the second link 6 swingably. Further, the backrest member 3 is swingably connected to the upper end of the back support rod 5 by a connecting pin 24. A coil spring 12 is provided between the lower portion of the backrest member 3 and the back support rod 5.

The lower end of the second link 6 is swingably connected to the rear portion of the seat plate 2 by a connecting pin 22. Second
A bracket 13 for attaching the waist support member 4 is fixed to the upper end of the link 6. The waist support member 4 is made of a plate material that is elastically deformable. In the present embodiment, the waist support member 4 is formed of a resin such as polypropylene or nylon. However, the resin used as the material of the lower back support member 4 is not limited to these, and the lower back support member 4 may be molded with a material other than resin.

The lumbar support member 4 is attached to the bracket 13 by attaching means 14 as shown in FIGS. In other words, this chair is equipped with the mounting means 14 that flexibly deformably mounts the waist support member 4, which is an elastically deformable plate member, to the bracket 13, which is the mounted member. The attachment means 14 includes a hole 15 provided in one of the bracket 13 and the waist support member 4, and a shaft member 16 provided in the other one and movable relative to the hole 15. The elastic member is inserted into the hole 15 and the relative positional relationship between the shaft member 16 and the hole 15 is displaced, so that the waist support member 4 is allowed to flex and deform. In the present embodiment, the hole 15 is formed in the waist support member 4,
A shaft member 16 is attached to the bracket 13. Also,
The hole 15 is, for example, a long hole. The waist support member 4 is slightly curved, for example, in the horizontal direction such that the central portion projects rearward, that is, when viewed from above, the central portion projects rearward. When the seated person leans against the waist support member 4, the waist support member 4 bends so as to project the center portion rearward while pulling both ends to the center, as shown by the chain double-dashed line in FIG. That is, the waist support member 4 is curved in the horizontal direction so as to project rearward while moving the hole 15 with respect to the shaft member 16.

The holes 15 are formed at positions facing the four corners of the bracket 13 of the waist support member 4, respectively. Since the waist support member 4 is curved so as to be recessed in the horizontal direction, that is, when viewed from above, the hole 15 is elongated in the horizontal direction. The shaft member 16 is, for example, a screw, and is screwed into the four corners of the bracket 13 from the front side of the waist support member 4 through the holes 15.

An edge portion of the waist support member 4 formed of a single plate member is bendable toward the rear side, and the bent portion 4a has a slit opened in a direction perpendicular to the bending line 4b. 17 are formed. Here, "foldable" means that the edge of the waist support member 4 may be bent in advance, or the edge of the waist support member 4 may be bent along the bending line 4b so that no load is applied. However, it may not be bent, but may be bent by being elastically deformed when a load is applied.
In the present embodiment, the upper and lower parts of the waist support member 4 are bent in advance toward the rear side to prevent the upper and lower edges 4c from hitting the waist of the seated person and depressing the seating comfort. That is, if the upper and lower parts of the waist support member 4 are simply bent, the upper and lower bent parts 4a function as ribs, making it difficult to bend the waist support member 4 in the horizontal direction. However, by providing the slit 17 in the bent part 4a. The bent portion 4a is divided into a plurality of square pieces to facilitate the horizontal bending of the waist support member 4.

A cushion member (not shown) is provided on the surfaces of the waist support member 4 and the backrest member 3, and is covered with a skin member (not shown).

When a seated person leans against the backrest member 3,
The back support rod 5 tilts about the connecting pin 18 at the lower end thereof, that is, moves so as to tilt backward, and the second link 6 also tilts about the connecting pin 22 at the lower end thereof in conjunction with this movement. At this time, since the seat plate 2 also inclines rearward, the lower end of the second link 6 descends by the distance Ld, but this descending distance Ld descends in conjunction with the tilting of the back support rod 5. Is smaller than the descending distance Lu of the upper end of the link 6. That is, the second
Since the upper end of the link 6 descends more than its lower end, the link 6 simply tilts more than the back support rod 5 tilted about the lower end, and the waist support member 4 tilts more than the backrest member 3 ( X1 <X2). For this reason,
The waist support member 4 can be receded with respect to the backrest member 3 so as to be retracted rearward.

That is, in the posture in which the backrest member 3 is not leaning strongly, the waist support member 4 firmly supports the waist of the seated person (FIG. 5). On the other hand, in a resting posture in which the backrest member 3 leans strongly and reclines, the lumbar support member 4 does not push up the lumbar region of the seated person, and the backrest member 3 and the lumbar support member 4 as a whole allow the seated person to have a large area. Support to wrap around (Fig. 6). That is, the seated person can be supported in a posture suitable for the work during the work, and the seated person can be supported in the posture suitable for the rest during the rest, so that the sitting comfort and usability of the chair can be improved.

Further, although the waist support member 4 is composed of one plate material, the bracket 13 of the waist support member 4 is used.
Since the attachment point to the lower back support member 4 is not restricted, the waist support member 4 can be largely bent depending on the leaning condition of the seated person. That is, when the lumbar support member 4 is directly fixed with screws or the like, that is, when the attachment point to the bracket 13 is constrained, the lumbar support member 4 is
Cannot be displaced with respect to the bracket 13,
The lumbar support member 4 is mainly bent by extensional deformation, and cannot be bent so much. On the other hand, as in the present invention, by allowing the lumbar support member 4 to be displaced with respect to the bracket 13 without restraining the mounting point by the mounting means 14, the lumbar support member 4
It is possible to greatly bend. Therefore, even if the waist support member 4 is molded using a material such as resin, the waist support member 4 can be largely curved.
Further, since the slits 17 are formed in the upper and lower bent portions 4a, the bent portion 4a is formed in the waist support member 4
It does not prevent the flexible deformation of the. For these reasons, the waist support member 4 can be reasonably curved to a large extent,
The seated person can be softly received and the sitting comfort can be improved. Further, since the bent portion 4a is provided to prevent the upper and lower edges 4c of the waist support member 4 from hitting and pressing the waist of the seated person, the sitting comfort can be further improved.

When the seated person leaning against the backrest member 3 and the waist support member 4 raises his / her upper body, the elastic member 8
The back support rod 5 and the second link 6 are returned to their original positions by the spring force, and the backrest member 3 and the waist support member 4 that have been reclining are raised. Further, the force that largely bends the waist support member 4 is also released, so that the waist support member 4 returns to the original shape shown by the solid line in FIG. 3 due to its elastic force.

The above-mentioned 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 scope of the present invention. For example, in the above description, the backrest member 3 is attached to the first link (back support rod) 5 swingably attached to the seat receiving member 1, and the second link 6 swingably attached to the seat plate 2. Although the waist support member 4 is attached to the seat support member 4, the waist support member 4 is attached to the first link 5 swingably attached to the seat receiving member 1, and the second link 6 is swingably attached to the seat plate 2. The backrest member 3 may be attached to the. That is, the second link 6 may be configured by the back support rod 5. With this configuration, for example, as shown in FIG. 7, the backrest member 3 can be tilted more largely than the lumbar support member 4 (X1> X2) at the time of reclining.

In the above description, the waist support member 4 is tilted more largely than the backrest member 3 (X1 <X2) so that the waist support member 4 can be retracted rearward of the backrest member 3 during reclining. , The backrest member 3 tilts more than the lumbar support member 4 (X
1> X2), and the waist support member 4 may be projected more than the backrest member 3 at the time of reclining. By making the lumbar support member 4 project more than the backrest member 3 at the time of reclining, the back muscle warped backward can be further extended and a stretching effect can be exerted.

Further, in the above description, the backrest member 3 as the back support and the lumbar support member 4 as the back lower region support are constituted by different members, but the back support 3 and the lower back region support 4 are the same. You may form in a member. For example, as shown in FIGS. 9 and 10, one back shell 27 may form the back support 3 and the lower back region support 4. A stretchable bent portion 28 is formed between the back support 3 and the lower back area support 4, and the back support 3 and the lower back area support 4 are bent at the stretchable bent portion 28, whereby the back support 3 and the lower back area support are supported. Similarly to the case where the back support 3 and the seat plate 2 are formed separately, the lower back region support 4 can be tilted by an amount different from the tilt amount of the back support 3 in association with the tilting of the back support 3 and the seat plate 2. The expansion / contraction bending portion 28 has a curved shape (FIG. 9) or a bellows shape (FIG. 1) that allows the back support 3 and the lower back area support 4 to be easily bent.
It is preferably 0).

In the present invention, the bending position 25 of the back support 3 and the lower back region support 4 is moved, or the back support 3 is attached to either the first link 5 or the second link 6, and which one is attached to the back support 3. It is possible to change the support state of the back and waist of the seated person when reclining, depending on whether the lower region support 4 is attached or the like. For example, in the configuration of FIG. 1, reclining from the state shown in FIG. 5 as shown in FIG. In this state, the lower back area support 4 tilts more than the back support 3 (X1 <X2), so that the lower back area support 4 retracts with respect to the back support 3, and as described above,
The whole of the backrest member 3 and the waist support member 4 supports the seated person so as to wrap it in a wide area. Also,
When the attachment of the backrest member 3 and the lumbar support member 4 is reversed with respect to the configuration of FIG. When the back support 3 is attached to the second link 6 that is swingably attached to the seat plate 2, the back support 3 is reclined as shown in FIG. 7. In this state, the back support 3 tilts more largely than the lower back area support 4 (X1> X
2) As a result, the inferior region support 4 protrudes with respect to the spine support 3, and the spine can be stretched. Further, the bending positions of the back support 3 and the lower back region support 4 with respect to the configuration of FIG. When 25 is provided above, that is,
When the lower back area support 4 is enlarged and the back support 3 is reduced by that amount, the reclining is performed as shown in FIG. In this state, the lower back area support 4 can support a seated person's waist and back in a wide range, and the back support 3 can support the seated person's shoulders to be raised. The monitor can be orthoscopically positioned and can take a posture suitable for operating the personal computer 26 while reclining.

In the configuration of FIG. 1, the connecting pin 18 connecting the back support rod 5 to the seat receiving member 1 is arranged at a lower position than the connecting pin 22 connecting the second link 6 to the seat plate 2. However, the configuration is not limited to this.
The connecting pin 18 may be disposed at a position higher than the connecting pin 22 as shown in FIG. That is, the connecting portion 29 that connects the second link 6 may extend below the connecting pin 18. With such a configuration, the backrest member 3
Can be tilted more largely than the waist support member 4 (X1> X2), and the waist support member 4 can be made to project more than the backrest member 3 during reclining.

Further, in the above description, the seat plate 2 is connected to the seat receiving member 1 and the second link 6, but the structure is not limited to this. For example, the seat plate 2 may be connected to the seat receiving member 1. Alternatively, the second link 6 may be connected to the seat plate 2 by connecting to the back support rod 5.

In the above description, the mounting means 14 is composed of the hole 15 and the shaft member 16, and the shaft member 16 and the hole 15 are provided.
Of the lumbar support member 4 by shifting the relative positional relationship of
Although the elastic deformation of the elastic member is allowed, the elastic member is not necessarily limited to this configuration. For example, an elastic member as the attaching means 14 is provided between the bracket (attached member) 13 and the waist support member (plate member) 4. By elastically deforming, the relative positional relationship between the bracket 13 and the lower back support member 4 may be shifted to allow the flexible deformation of the lower back support member 4. The elastic member is, for example, anti-vibration rubber.

Further, in the above description, the lumbar support member 4 as the plate member is mounted by the mounting means 14, but plate members other than the lumbar support member 4, such as the seat plate 2 and the backrest member 3, are flexibly deformed by the mounting means 14. You may make it possible to attach it.

Further, in the above description, the hole 15 is a long hole, but it may be a circular hole as shown in FIG. 12 (A) or a rhombic hole as shown in FIG. 12 (B). C)
It may be a cross-shaped hole as shown in FIG.

Further, in the above description, the shape of the slit 17 is made into an elongated notch and the bent portion 4a is divided into square pieces. However, by changing the shape of the slit 17, the bent portion 4a is formed into a triangular piece (see FIG. 13). ), Trapezoidal piece (Fig. 1
4), a semicircular piece (FIG. 15) or the like.

Further, in the above description, the edge portion of the waist support member 4 is bent to form the bent portion 4a, but the bent portion 4a may not be formed. However,
It is desirable to form the bent portion 4a in the waist support member 4 when a cushion material is wrapped around the waist support member 4 or when the backrest member 3 is elastically deformed due to design requirements.

Further, as shown in FIG. 3, the shape of the waist support member 4 in a state where the seated person is not leaning may be one which is curved in the horizontal direction so as to project rearward. It is not limited to, for example, FIG.
As shown in FIG. 5, it may be curved in the horizontal direction so as to project forward. Further, as shown in FIG. 17, it may be curved in the vertical direction so as to project backward, or may be curved in the vertical direction so as to project forward as shown in FIG. When the seated person leans against the waist support member 4, the waist support member 4 is curved in the horizontal direction so as to project rearward in the example of FIG. 16, so that the hole 15 is elongated in the horizontal direction. On the other hand, FIG.
Further, in the example of FIG. 18, the waist support member 4 is curved in the vertical direction so as to project rearward, so that the hole 15 is formed elongated in the vertical direction.

Further, reinforcing means 30 for reinforcing the hole 15 may be provided. As the reinforcing means 30, for example, FIG.
It is a rib formed so as to surround the hole 15 as shown in (A) and (B). In this case, the rib 3 as a reinforcing means
0 as shown in FIG. 19 (B).
It may be formed only on one side surface, or may be formed on both surfaces of the waist support member 4 as shown in FIG.
Furthermore, as the reinforcing means 30, as shown in FIG. 20, an eyelet-shaped cylindrical body may be used. The material of the cylindrical body 30 is, for example, metal, rubber, resin or the like.

Further, a cushioning means 31 attached between the hole 15 and the shaft member 16 may be provided. Buffer means 31
For example, as shown in FIG. 21, it is a cylindrical body attached to the shaft member 16. The material of the cylindrical body 31 is, for example, resin or rubber.

[0037]

As described above, in the chair according to the first aspect, the first link swingably attached to the seat receiving member and the second link swingably attached to the seat plate are provided. And a back support is attached to either one of the first link and the second link, and a back back region support is attached to the other of the first link, and the first link and the second link are swingably connected, Since the lower back area support is tilted by an amount different from the tilting amount of the back support in conjunction with the tilting of the back support and the seat plate, the back support and the lower back area support can be tilted in conjunction with each other. Of course, the lower back region support can be retracted or projected relative to the back support when tilting. For this reason,
It is possible to improve the usability and comfort of the chair.

Further, in the chair according to the second aspect, since the first link is constituted by the back support rod, it is not necessary to provide the first link as a new component, and the increase in the number of components is suppressed accordingly. It is possible to suppress an increase in manufacturing cost.

Further, in the chair according to claim 3, a back support is attached to the first link and a back back area support is attached to the second link 6, respectively, and the back back area support is linked to the tilt of the back support. Since it is tilted more than the support, it is possible to recline so that the lower back region support is retracted with respect to the back support. Therefore, the waist of the seated person can be firmly supported when the user is not reclining, and the user can sit comfortably without reclining the waist when the user reclines. That is, it is possible to provide a chair that is easy to use and comfortable to sit on.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an example of an embodiment of a chair to which the present invention is applied.

FIG. 2 is a rear view of the attachment structure of the waist support member of the chair.

FIG. 3 is a cross-sectional view of the mounting structure of the waist support member of the chair seen from above.

FIG. 4 is an enlarged sectional view showing a mounting structure of a waist support member of the chair.

FIG. 5 is a conceptual diagram showing a state in which a backrest member and a waist support member support a seated person and is not reclining.

FIG. 6 is a conceptual diagram showing a state in which a backrest member and a waist support member support a seated person, and in a reclining state.

FIG. 7 is a conceptual diagram of a reclining state in an embodiment suitable for stretching the spine, showing how the backrest member and the waist support member support a seated person.

FIG. 8 is a conceptual diagram of a reclining state in an embodiment suitable for performing a personal computer operation, showing how a backrest member and a waist support member support a seated person.

FIG. 9 is a perspective view showing a back shell in which a back support and a lower back region support are integrated, as seen from an oblique rear side thereof.

FIG. 10 is a perspective view showing a modified example of the back shell of FIG. 9 as seen obliquely from the rear.

FIG. 11 is a schematic configuration diagram illustrating another embodiment of the chair to which the present invention is applied and illustrating the arrangement of connecting pins.

FIG. 12 shows a modified example of the hole of the plate material mounting structure of the chair, (A) is a perspective view of a circular hole, (B) is a perspective view of a rhombic hole,
(C) is a perspective view of a cross-shaped hole.

FIG. 13 is a perspective view showing a first modification of the bent portion of the waist support member.

FIG. 14 is a perspective view showing a second modified example of the bent portion of the waist support member.

FIG. 15 is a perspective view showing a third modified example of the bent portion of the waist support member.

FIG. 16 is a perspective view showing a first modified example of the shape of the lower back support member when viewed obliquely from the front.

FIG. 17 is a perspective view showing a second modified example of the shape of the lower back support member when viewed obliquely from the front.

FIG. 18 is a perspective view showing a third modified example of the shape of the lower back support member when viewed obliquely from the front.

FIG. 19 shows a reinforcing means for a hole, (A) is a perspective view,
(B) is sectional drawing, (C) is sectional drawing of a modification.

FIG. 20 is a cross-sectional view showing another example of the hole reinforcing means.

FIG. 21 is a cross-sectional view showing a buffer means.

FIG. 22 is a side view of a conventional chair.

[Explanation of symbols]

1 Seat receiving member 2 seat plate 3 Backrest member (back support) 4 Lumbar support members (support for lower back area) 5 back support rod (1st link) 6 second link X1 Backrest tilt amount X2 Inclination of lumbar support member

Claims (3)

[Claims] 1. A chair having a seat plate swingably attached to a seat receiving member and having a back support and a lower back region support, a first link swingably attached to the seat receiving member, and the seat. A second link swingably attached to the plate is provided, and the back support is attached to either one of the first link and the second link, and the back lower region support is attached to the other, respectively, The first link and the second link are swingably connected, and the lower back region support is tilted by an amount different from the tilting amount of the back support in association with tilting of the back support and the seat plate. A chair characterized by that. 2. The chair according to claim 1, wherein the first link is composed of a back support rod. 3. The back support on the first link,
The chair according to claim 2, wherein the lower back area support is attached to each of the second links, and the lower back area support is tilted more largely than the back support in association with tilting of the back support.