WO2014061732A1 - Chair - Google Patents

Abstract

A chair (1) provided with a leg body (10), a backrest support body (20) supported by the leg body (10), and a backrest body (50A) for supporting the back of the seat occupant, the backrest body (50A) being supported by the backrest support body (20). The backrest body (50A) is provided with: a backrest (50) having an upholstery material (51) which receives the back of the seat occupant and which is flexible so as to be capable of deforming in accordance with the back, and a pair of vertical frame parts (53A, 53B) to which the upholstery material (51) is attached, the pair of vertical frame parts (53A, 53B) being set apart from each other in the width direction and being capable of being elastically deformed by the force applied from the upholstery material (51); and a backrest rear support member (40) for linking the vertical frame parts (53A, 53B) in the vertical direction.

Description

Chair

The present invention relates to a chair.
This application claims priority based on Japanese Patent Application No. 2012-230929 for which it applied on October 18, 2012, and uses the content here.

A chair is generally known to have various configurations based on a basic configuration including a leg, a seat provided on an upper portion of the leg, and a back for supporting a seated person sitting on the seat. Yes.

For example, a chair having a back member and an arm that extends upward from a leg and supports a portion spaced apart in the width direction on the rear surface of the back member from the rear is proposed as a support structure for the back part of the chair. (See Patent Document 1 below).

Also, a backrest having a back frame composed of an upper frame portion, a lower frame portion, a left frame portion and a right frame portion, and a back plate placed inside the back frame, and a left frame portion and a right frame of the backrest A chair provided with a back strut that supports the part from the back has also been proposed (see Patent Document 2 below).
In such a chair, the back plate can reliably support the back of the seated person via the back frame supported by the back column.

US Pat. No. 7,249,802 JP 2009-1112729 A

However, in the configuration described in Patent Document 1, even when a backward force acts on the back member from the seated person, the back member is reliably supported by the axial force of the arm. Is prevented from being deformed. Therefore, even if the seated person takes a posture in which the back is tilted backward, it is difficult to deform the seated person so that the back of the seated person is largely tilted backward.

In the configuration described in Patent Document 2, the back column supports the left frame portion and the right frame portion. Therefore, even if a backward force is applied to the back plate from the seated person, the left frame portion and the right frame The deformation of the part is restricted, and the deformation of the back plate provided in the left frame part and the right frame part is also restricted. Therefore, even if the seated person takes a posture in which the back is tilted backward, it is difficult to deform the seated person so that the back of the seated person is largely tilted backward. For this reason, in the chairs as described in Patent Documents 1 and 2, the seated person cannot freely move the back backward while sitting down, and cannot follow the change in posture. There's a problem.

The present invention has been made in view of the above circumstances, and provides a chair capable of following the posture when a seated person moves the back backward.

(1) According to the first aspect of the present invention, the chair includes a leg, a backrest support, and a backrest. The backrest support is supported by a leg. The backrest is supported by the backrest support and supports the back of the seated person. The backrest receives the back of the seated person and has a flexible tension material that can be deformed according to the back, and the tension material is attached, and elastic deformation is performed by a force acting from the tension material. A backrest having a pair of vertical frame portions spaced in the possible width direction, and a backrest rear support member that connects the vertical frame portions in the vertical direction.

According to the configuration described above, the load acting from the seat occupant to the upholstery material rearward is transmitted to the pair of vertical frame portions attached to the upholstery material and spaced apart in the width direction. The vertical frame portion is elastically deformed by the force applied from the upholstery material and is deformed so as to incline backward, and the upholstery material attached between the vertical frame portions moves rearward over the entire width direction. Further, since the backrest support member connects the vertical frame portions in the vertical direction, the posture of the backrest support member also tilts backward as the vertical frame portion tilts backward. Therefore, when the seated person's load acts in a direction to tilt the backrest backward, the entire backrest body can be tilted backward so as to follow the operation of tilting the backrest.

(2) In the chair of (1) above, the backrest is supported by the backrest support member and supports the back of the seated person. The backrest rear support member is supported by the backrest support. The backrest rear support member may include a lower connecting portion, a deformation allowing portion, and an upper connecting portion. The lower connecting part is connected to the backrest support. The deformation allowing portion extends upward from the lower connecting portion and is elastically deformable according to a load acting on the backrest from the back of the seated person. The upper connecting portion extends upward from the upper end of the deformation allowing portion, and is connected to the backrest at the upper end.

According to the configuration described above, when a load acts backward from the seated person on the backrest, the load on the seated person is transmitted to the backrest support member that supports the backrest. At this time, among the backrest supporting members, the deformation allowing portion provided between the lower connecting portion connected to the backrest supporting member and the upper connecting portion connected to the backrest gradually increases. It is elastically deformed so as to incline backward. Along with the deformation of the deformation allowing portion, the backrest supported by the backrest rear support member can largely tilt the posture backward.
Moreover, the upper connection part is provided above the deformation | transformation permission part which inclines toward back. Therefore, as the deformation allowing portion is inclined rearward, the upper connecting portion can move rearward while maintaining the state where the upper end is connected to the backrest. Therefore, when the seated person's load acts in the direction of tilting the backrest backward, the backrest can be tilted backward so as to follow the operation of tilting the backrest.

(3) In the chair of (2) above, the upper connecting portion may be formed so as to be gradually inclined forward as it goes upward.

According to the configuration described above, the upper connecting portion is formed so as to be gradually inclined forward as it goes upward, so that the deformation of the upper connecting portion itself is suppressed in the front-rear direction to support the load of the seated person. In addition, the backrest connected to the upper connecting portion can reliably support the load of the seated person.
On the other hand, when the deformation permitting portion is deformed, the backrest connected to the lower connecting portion and the upper connecting portion of the backrest supporting member can be inclined rearward according to the load of the seated person.

(4) In the chair of (2) or (3), the upper connecting portion is connected to the deformation allowing portion at a lower end and is formed in a V shape so as to be separated from each other as it goes upward. You may have a pair of connection piece by which the upper end was connected with the said backrest.

According to the configuration described above, the upper ends of the pair of connecting pieces are connected to the backrest, so that the load acting on one side or the other side in the width direction from the seated person can be reliably supported.

(5) In the chair according to any one of (2) to (4) above, the vertical frame portion is connected to the lower connecting portion at the lower end, and gradually tilts forward as it goes upward. The lower material is formed so as to extend upward from the lower material, and is inclined rearward relative to the lower material as it goes upward, and is connected to the upper connecting portion at the upper end. And may have an upper material.

According to the above configuration, since the lower material is inclined forward as it goes upward, the deformation of the lower material itself can be suppressed and the load on the seated person can be reliably supported. On the other hand, since the upper material is inclined rearward relative to the lower material as it goes upward, it can be made to follow rearward according to the load of the seated person.
Here, the vertical frame portion connected to the back support member at the upper and lower portions is inclined within the range of the upper material in the vertical direction while suppressing deformation of the lower material. Therefore, when the backrest supporting member is inclined rearward, the upper material is inclined at a larger inclination angle than the backrest supporting member.
For this reason, the vertical frame portion can be largely inclined rearward and effectively followed by the back of the seated person while minimizing the deformation amount of the deformation allowing portion of the backrest supporting member. Therefore, even when the deformation of the deformation allowing portion is repeated and the moment is concentrated, there is no possibility of damage or breakage.

(6) In the chair of (5) above, the upholstery material may have a lower part connected to the lower material and an upper part connected to the upper material.

According to the above-described configuration, when a load acts on the backrest from the seated person, the backrest tension material is deformed along the back of the seated person, and the deformable portion of the backrest supporting member that supports the backrest. Is elastically deformed. Therefore, when the seated person's load acts in the direction of tilting the backrest backward, the backrest can be tilted backward so as to follow the motion of tilting the backrest, and the seated person's load is tilted backward. You can catch it as if it wraps your back.

According to the above-described chair, when the seated person takes the action of tilting his back backward, the posture can be followed.

It is the perspective view which looked at the chair which concerns on one Embodiment of this invention from diagonally forward. It is the perspective view which looked at the upper part of the chair concerning one embodiment of the present invention from back. It is a side view of the normal time of the chair which concerns on one Embodiment of this invention. It is a side view at the time of a seated person leaning back on the chair which concerns on one Embodiment of this invention. It is the perspective view which looked at the chair concerning one embodiment of the present invention from the front. It is a side view of the chair concerning one embodiment of the present invention. FIG. 5 is a cross-sectional view taken along line PP of FIG. 4 in a normal state of the chair according to the embodiment of the present invention. FIG. 5 is a cross-sectional view taken along line PP of FIG. 4 in a state where a seated person is seated on a chair according to an embodiment of the present invention. It is the perspective view which looked at the normal time of the chair concerning one embodiment of the present invention from the upper part. In the chair which concerns on one Embodiment of this invention, it is the perspective view which looked at the case where it took the attitude | position which turns around back from the width direction one side. It is the perspective view which looked at the upper part of the chair which concerns on the modification of one Embodiment of this invention from back.

Hereinafter, a chair according to an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the chair 1 according to this embodiment includes a leg body 10, a backrest support body 20, a seat portion 30, a backrest support member 40, and a backrest 50.
The leg 10 is provided on the floor surface F. The backrest support 20 is supported by the legs 10. The seat portion 30 is provided on the backrest support 20 and can be seated by a seated person. The backrest rear support member 40 is supported by the backrest support 20. The backrest 50 is supported by the backrest rear support member 40 and supports the back of the seated person. Details of each component will be described below. In the following description, the direction in which the occupant sits and leaves is the front-rear direction, the side on which the occupant sits is the front, the opposite side is the rear, and the direction in the horizontal plane perpendicular to the front-rear direction is the width direction. And the side away from the chair in the width direction is the side.

(Leg)
The leg body 10 includes a plurality of leg rods 12 provided with casters 11 capable of turning on the floor surface F, and leg columns 13 supported by the plurality of leg rods 12. The plurality of leg rods 12 are radially arranged and connected to each other at the base ends, and casters 11 are attached to the respective tips.
The lower part of the pedestal 13 is connected to the base ends of the plurality of leg rods 12 and is erected upward. Further, a support base 14 having a built-in reclining mechanism (not shown) that allows the backrest support 20 to tilt backward is attached to the upper portion of the pedestal 13.

(Backrest support)
The backrest support 20 includes a pair of forward arm portions 21 whose base portions are pivotally attached to both sides in the width direction of the support base 14, and a seat portion that extends upward from the base portion of the forward arm portion 21. A pair of upward arm portions 22 that support 30 and a pair of backward arm portions 23 that extend rearward from the base portion of the forward arm portion 21.

As shown in FIG. 2, the pair of rearward arm portions 23 are arranged so as to gradually approach each other toward the rear and are connected to each other at the rear end so that they are integrally arranged in a downward V-shape. Has been. The rear ends of the pair of rearward arm portions 23 are fixed to the lower portion of a backrest supporting member 40 described later.

Further, as shown in FIG. 1, the backrest support 20 is provided with an armrest 26 extending upward from the side.

(Seat)
As shown in FIGS. 3A and 3B, the seat portion 30 is supported at the front portion so as to be slidable in the front-rear direction with respect to the support base 14, and is pivotally attached to the upper arm portion 22 of the backrest support 20. ing. As the backrest support 20 is tilted rearward by the reclining mechanism of the support base 14, the seat 30 is configured to move rearward relative to the support base 14 and tilt the rear side downward. Has been.

(Back support member)
As shown in FIG. 2, the backrest rear support member 40 includes a lower connecting portion 41 connected to the backrest support 20, a deformation allowing portion 42 extending upward from the lower connecting portion 41, and the deformation allowing And an upper connecting portion 43 arranged so as to gradually spread outward in the width direction from the upper end of the portion 42 upward.

The lower connecting portion 41 is formed with a recess (not shown) in which the rear ends of the pair of rear arm portions 23 of the back support 20 are fitted on the lower rear surface. Is fitted. The lower connecting portion 41 is fixed to the upper portion of the backrest support 20 at the recess by screwing with, for example, a bolt and a nut (not shown). Further, the lower connecting portion 41 is connected to the backrest 50 at the lower end.

As shown in FIGS. 1, 4 and 5, the deformation allowing portion 42 has a lower end connected to the lower connecting portion 41 and arranged upward, and an upper end connected to the upper connecting portion 43. Further, the deformation allowing portion 42 is formed such that the length dimension in the width direction gradually becomes narrower as it goes upward, and the length dimension in the width direction becomes wider again as it goes from the middle to the upper side.

The deformation allowing portion 42 has no rib on the front surface thereof, and is configured to be easily elastically deformed according to a load acting on the backrest 50 from the back of the seated person.
Even if ribs are provided on the surface of the deformation-permitting portion 42, the material can be elastically deformed according to the load acting on the backrest of the seated person by adjusting the material and thickness of the deformation-permitting portion 42. be able to.

The upper connecting portion 43 is formed such that the lower end is connected to the deformation allowing portion 42 and gradually spreads outward in the width direction as it goes upward, and gradually inclines forward as it goes upward.

In the present embodiment, the upper connecting portion 43 has a pair of connecting pieces 43A and 43B which are arranged so as to be gradually separated from each other in the width direction as they go upward, and whose upper ends are connected to the backrest 50. The pair of connecting pieces 43A and 43B are formed in a V shape as a whole.

The pair of connecting pieces 43A and 43B constituting the lower connecting portion 41, the deformation allowing portion 42, and the upper connecting portion 43 are integrally formed, and the backrest supporting member 40 is rearward as viewed from the side as a whole. It is curved so as to be convex.

That is, the lower connecting portion 41 is curved so as to go backward as it goes upward as a whole. Further, the pair of connecting pieces 43A and 43B constituting the upper connecting portion 43 are inclined so as to go forward as they go upward while being curved. The deformation | transformation permission part 42 has connected the upper connection part 43 and the lower connection part 41, curving.

(Backrest)
As shown in FIG. 2, the backrest 50 includes a tension member 51 that receives the back of the seated person, and an upper frame portion 52 to which the tension member 51 is attached and connected to the upper connection portion 43 in the backrest support member 40. And a pair of vertical frame portions 53A and 53B (53) which are connected to the upper frame portion 52 and to which the upholstery material 51 is attached.

The upholstery material 51 is composed of a flexible member that receives the back of the seated person and can be deformed according to the posture of the back. Specifically, in this embodiment, it is formed of a mesh-like material, and the entire thread material constituting the mesh elastically expands and contracts, so that it can be flexibly deformed as a whole. The upholstery material 51 is provided in a portion surrounded by the upper frame portion 52 and the pair of vertical frame portions 53, and ends thereof are fixed to the upper frame portion 52 and the pair of vertical frame portions 53.

The upper frame portion 52 extends along the width direction, and both ends thereof are connected to the upper ends of the pair of connecting pieces 43A and 43B in the upper connecting portion 43, and are connected to the upper ends of the pair of vertical frame portions 53A and 53B, respectively. Has been.

One vertical frame portion 53A has a lower member 57A and an upper member 56A that is connected to the upper end of the lower member 57A and can be elastically deformed by a force acting from the tension member 51. Similarly, the other vertical frame portion 53B has a lower member 57B and an upper member 56B that is connected to the upper end of the lower member 57B and can be elastically deformed by a force acting from the tension member 51.

As shown in FIGS. 2 and 5, the lower members 57A and 57B are connected at the lower ends to the lower connecting portion 41 of the back support member 40, and gradually expand toward the front and outward in the width direction as they go upward. Is formed. Each of the lower members 57A and 57B is formed so that the cross-sectional dimension decreases as it goes upward.

The upper members 56A and 56B are configured to be elastically torsionally deformable and elastically bendable and deformable according to a load acting from the back of the seated person.

The upper members 56A and 56B have lower ends connected to the corresponding lower members 57A and 57B, and upper ends connected to the pair of connecting pieces 43A and 43B of the upper frame portion 52 and the backrest support member 40, and head upward. Accordingly, the lower members 57A and 57B are formed so as to be inclined rearward relative to the lower members 57A and 57B.

In the present embodiment, the upper members 56A and 56B are formed so as to be gradually inclined rearward from the upper ends of the lower members 57A and 57B upward.

As described above, the vertical frame portions 53A and 53B are formed so as to gradually move forward from the lower portion 57A and 57B toward the upper side from the lower portion, and between the lower members 57A and 57B and the upper members 56A and 56B. The upper portions 56A and 56B are formed so as to gradually move forward from the connecting portion toward the upper side, and the vertical frame portions 53A and 53B are formed so as to be convex toward the front as a whole. ing.

As shown in FIG. 2, the backrest support member 40 and the vertical frame portion 53 are integrally formed in an annular shape when viewed from the side. In this embodiment, the lower connecting portion 41, the deformation allowing portion 42, the one connecting piece 43A of the backrest support member 40, the upper member 56A and the lower member 57A of the one vertical frame portion 53A are annular in a side view. A first annular portion 61 is configured.

Further, the second connecting portion 41, the deformation allowing portion 42, the other connecting piece 43B, the upper member 56B and the lower member 57B of the other vertical frame portion 53B of the backrest supporting member 40, which are annular in a side view, are viewed from the side. An annular portion 62 is configured.

The first annular portion 61 and the second annular portion 62 are connected by the lower connecting portion 41 and the deformation allowing portion 42 and are integrally formed as a whole. The upper frame portion 52 is also integrally formed so that the upper ends of the first annular portion 61 and the second annular portion 62 are connected.

That is, in this embodiment, each part of the backrest support member 40, the upper frame part 52 of the backrest 50, and the pair of vertical frame parts 53A and 53B are integrally formed.

Further, the backrest body 50A is constituted by the backrest support member 40 and the backrest 50. That is, the backrest 50A is supported by the backrest support 20, and supports the back of the seated person.

Next, the operation of the backrest support member 40 and the backrest 50 of the chair 1 when a seated person sits on the seat 30 of the chair 1 configured as described above will be described.

The solid line in FIG. 4 and FIG. 6A show the chair 1 in a state where the seated person sits on the seat portion 30 and does not lean on the backrest 50, and the two-dot chain line in FIG. The chair 1 in a state of being drowned is shown.

When the seated person sits on the seat portion 30, a force from the seated person acts on the tension member 51 of the backrest 50, and the thread material constituting the mesh of the tension member 51 elastically expands and contracts by this force. Then, along the back of the seated person, it is elastically deformed into an arc shape so that the substantially central portion in the width direction protrudes rearward.

Further, the vertical frame portions 53A and 53B to which the upholstery material 51 is fixed are elastically deformed so that the inner side in the width direction is directed rearward by the force applied from the upholstery material 51, and inward in the width direction so as to be close to each other. Moving.

As the vertical frame portions 53A and 53B are elastically deformed, the upholstery material 51 can be further deformed into an arc shape in which a substantially central portion in the width direction protrudes rearward, and the backrest 50 is a backrest rear portion. It is supported by the support member 40.

Further, when the seated person droops greatly in the backrest 50, as shown by a two-dot chain line in FIG. 5, the deformation-allowing portion of the backrest support member 40 connected to the vertical frame portions 53A and 53B. 42 is elastically deformable according to a load acting on the backrest 50 from the back of the seated person. Therefore, the deformation | transformation permission part 42 deform | transforms so that it may incline back gradually as it goes upwards centering on the lower end. As the deformation allowing portion 42 is deformed, the upper connecting portion 43 disposed above the deformation allowing portion 42 moves rearward, and the backrest 50 connected to the upper connecting portion 43 is further inclined rearward. It becomes possible.

In addition, when the seated person takes a posture of turning back from one side in the width direction of the backrest 50 from the state shown in FIG. 7A, the load from the seated person is as shown in FIG. The load acts on one side in the width direction of the backrest 50, and a load that twists and deforms the vertical frame portion 53B acts on the vertical frame portion 53B on the biased side.

Here, the upper member 56B in the vertical frame portion 53B is configured to be torsionally deformable by a force acting from the backrest 50. In addition, since the connecting pieces 43A and 43B are formed so as to be narrowed so that the connecting pieces 43A and 43B move downward, and are joined to each other and connected to the deformation allowing portion 42, the deformation allowing portion 42 promotes torsional deformation of the upper member 56B. It is configured. Accordingly, the upper member 56B is twisted and deformed toward the rear side so as to follow the back of the seated person according to the load of the seated person.

Further, since the connecting piece 43B connected to the upper member 56B is configured to be displaceable with the twist of the upper member 56B, the connecting piece 43B is moved to the rear side with the twist toward the rear side of the vertical frame portion 53B. Displace.
The upholstery material 51 in the backrest 50 is elastically deformed so as to wrap around the back of the seated person by elastically expanding and contracting the thread material constituting the mesh of the upholstered material 51 by a load from the seated person.

Thus, the upper material 56B, the connecting piece 43B, and the upholstery material 51 are deformed so as to wrap around the back and shoulders following the deformation of the back and shoulders of the seated person.
The same operation is performed when the seated person takes a posture of turning back from the other side in the width direction of the backrest 50.

In the chair 1 configured as described above, when a load acts on the backrest 50 from the seated person toward the back, the upper part of the backrest support member 40 that supports the upper frame portion 52 of the backrest 50 is supported by the load of the seated person. It is transmitted to the connecting part 43. At this time, in the backrest support member 40, the deformation allowing portion 42 provided between the lower connection portion 41 connected to the backrest support 20 and the upper connection portion 43 connected to the backrest 50 is provided. As it goes upward, it is elastically deformed so that it gradually inclines backward. Along with the deformation of the deformation allowing portion 42, the backrest 50 supported by the backrest rear support member 40 can be largely inclined backward.

Further, an upper connecting portion 43 is provided above the deformation allowing portion 42 that is inclined rearward. Therefore, as the deformation allowing portion 42 is inclined rearward, the upper connecting portion 43 can move rearward while maintaining the state where the upper end is connected to the backrest 50. Therefore, when the seated person's load acts in the direction of tilting the backrest backward, the backrest 50 can be tilted backward so as to follow the operation of tilting the backrest 50.

Further, in the normal state, the upper connecting portion 43 is formed so as to be gradually inclined forward as it goes upward, so that the deformation of the upper connecting portion 43 itself is suppressed in the front-rear direction and the load on the seated person is reduced. The backrest 50 connected to the upper connecting portion 43 can also reliably support the seated person's load.
On the other hand, when the seat occupant leans back in the back, when a load larger than the normal state is applied to the backrest in the backward direction, the deformation allowing portion 42 is deformed by the load, so that the back support member 40 of the backrest 40 The backrest 50 connected to the lower connecting portion 41 and the upper connecting portion 43 can be tilted rearward according to the load of the seated person, and can follow the operation of tilting the back of the seated person backward.

On the other hand, the pair of connecting pieces 43A and 43B of the upper connecting portion 43 is connected to the backrest 50 at the upper end, thereby reliably supporting a load acting on one side or the other side in the width direction from the seated person to the backrest 50. can do.

Further, since the lower members 57A and 57B are inclined forward as they move upward, the deformation of the lower members 57A and 57B themselves can be suppressed and the load on the seated person can be reliably supported.
On the other hand, since the upper members 56A and 56B are formed so as to be gradually inclined rearward from the upper ends of the lower members 57A and 57B, the upper members 56A and 56B are inclined rearward according to the load of the seated person, It is possible to follow the movement of tilting the back of the seated person backward.

Here, the backrest 50 connected to the lower connecting portion 41 and the upper connecting portion 43 of the back support member 40 at the upper and lower portions is prevented from being deformed by the lower members 57A and 57B, and the upper members 56A and 56B. It will incline within the vertical range. Therefore, when the backrest rear support member 40 is tilted rearward, the upper members 56 </ b> A and 56 </ b> B are tilted at a greater tilt angle than the backrest rear support member 40.
For this reason, the backrest 50 can be largely inclined rearward while keeping the amount of deformation of the deformation-permitting portion 42 of the backrest rear support member 40 to a minimum, and can follow the seated person's back more effectively. . Therefore, even when the deformation of the deformation allowing portion 42 is repeated and the moment is concentrated, there is no possibility of damage or breakage.

Further, with respect to the force acting backward from the seated person, when the seated person's back is received by the upholstery material 51 of the backrest 50, the load of the seated person is transferred from the upholstery material 51 to the upper frame portion 52 and a pair of This is transmitted to the vertical frame portions 53A and 53B. The upper frame portion 52 is connected and supported by a pair of connecting pieces 43 </ b> A and 43 </ b> B of the backrest rear support member 40, and the backrest rear support member 40 is supported by the backrest support 20. Therefore, the load from the seated person can be reliably supported by the upper frame portion 52, the backrest support member 40, and the backrest support body 20.

On the other hand, the upper members 56A and 56B of the pair of vertical frame portions 53A and 53B connected to both ends in the width direction of the upper frame portion 52 are elastically bent and deformed by the force acting from the upholstery material 51. It can be received so as to follow the seated person's back according to the load and wrap the back together with the upholstery material 51. For this reason, the seated person can be seated in a stable state.

Furthermore, when the seated person takes a posture that turns from one side in the width direction to the rear, the load from the seated person acts biased to one side in the width direction of the backrest 50, and the vertical side of the biased side A load that twists and deforms the vertical frame portions 53A and 53B acts on the frame portions 53A and 53B. Since the upper members 56A and 56B of the vertical frame portions 53A and 53B are torsionally deformed by the force acting from the tension member 51, the upper members 56A and 56B are deformed so as to follow the deformation of the back and shoulders of the seated person according to the load of the seated person. The backrest 50 can be tilted backward by receiving the back so as to be wrapped with the upholstery.

Further, when the load from the seated person is transmitted from the tension member 51 of the backrest 50 to the pair of vertical frame portions 53A and 53B, the upper members 56A and 56B of the vertical frame portions 53A and 53B are torsionally deformed. The pair of connecting pieces 43A and 43B connected to the upper members 56A and 56B are displaced with the torsional deformation of the upper members 56A and 56B. Therefore, when the posture is such that it turns backward from one side in the width direction, the upper members 56A and 56B on one side are torsionally deformed, and the connecting pieces 43A and 43B on one side are displaced to stretch the back. Since it can be received so as to be wrapped together with the material, it can be stably supported in the state following the deformation on the back and shoulders of the seated person.

In this manner, the upper members 56A and 56B, the upholstery material 51, and the connecting pieces 43A and 43B of the vertical frame portions 53A and 53B follow the deformation of the seated person's back and shoulders, and these backs and The shoulder can be stably supported.

On the other hand, the lower members 57A, 57B of the vertical frame portions 53A, 53B together with the upholstery material 51 reliably support the waist around the seated person's back. Therefore, when taking the posture of turning from one side in the width direction to the rear, the lower members 57A and 57B can support the waist of the seated person together with the upholstery material 51.

(Modification)
Next, the chair 101 which concerns on the modification of embodiment shown above is demonstrated using FIG.
In the chair 1, a pair of rearward arm portions 23, 23 of the backrest support 20 are connected to the lower portion of the backrest rear support member 40. On the other hand, in the chair 101 according to the modified example, the pair of rearward arm portions 123 and 123 of the backrest support body 120 are connected to the lower members 57A and 57B of the pair of vertical frame portions 53A and 53B. That is, the vertical frame portions 53A and 53B are supported by the backrest support body 120.
Specifically, like the lower members 57A and 57B, the upper portions of the rearward arm portions 123 and 123 are formed to gradually move forward as they move upward. The upper parts of these rearward arm parts 123 and 123 are connected to the lower members 57A and 57B.
In addition, a recess for attaching the pair of rearward arm portions 23 and 23 is not formed on the surface of the lower connection portion 141 of the backrest support member 140.

In the chair 101 configured as described above, a load acting backward from the seated person on the upholstery material 51 is transmitted to the pair of vertical frame portions 53A and 53B attached to the upholstery material 51 and separated in the width direction. The vertical frame portions 53A and 53B are elastically deformed by the force acting from the tension material 51 and deformed so as to incline backward, and the tension material 51 attached between the vertical frame portions 53A and 53B is rearward over the entire width direction. Move to. Further, since the backrest rear support member 140 connects the vertical frame portions 53A and 53B in the vertical direction, the backrest rear support member 140 moves its posture backward as the vertical frame portions 53A and 53B are inclined rearward. Tilt. Therefore, when the seated person's load acts in a direction to tilt the backrest 50 backward, the entire backrest 50 can be tilted backward so as to follow the operation of tilting the backrest body 50A.

Further, when the seated person sits on the seat portion 30 of the chair 101, the force from the seated person acts on the upholstery material 51 of the backrest 50 as in the above-described embodiment, and this force causes the upholstery material 51. When the thread material constituting the mesh elastically expands and contracts, it is elastically deformed in an arc shape so that the substantially central portion in the width direction protrudes rearward along the back of the seated person as a whole.

Further, the vertical frame portions 53A and 53B to which the upholstery material 51 is fixed are elastically deformed so that the inner side in the width direction is directed rearward by the force applied from the upholstery material 51, and inward in the width direction so as to be close to each other. Moving.

As the vertical frame portions 53A and 53B are elastically deformed, the upholstery material 51 can be further deformed into an arc shape in which a substantially central portion in the width direction protrudes rearward, and the backrest 50 is a backrest rear portion. It is supported by the support member 140.

In addition, when the seated person takes a posture of turning back from one side in the width direction of the backrest 50, the load from the seated person is the width of the backrest 50 as in the above-described embodiment. The load acts to be biased to one side in the direction, and a load that twists and deforms the vertical frame portions 53A and 53B acts on the vertical frame portions 53A and 53B on the biased side. Since the upper members 56A and 56B of the vertical frame portions 53A and 53B are torsionally deformed by the force acting from the tension member 51, the upper members 56A and 56B are deformed so as to follow the deformation of the back and shoulders of the seated person according to the load of the seated person. The backrest 50 can be tilted backward by receiving the back so as to be wrapped with the upholstery.

Also, the pair of connecting pieces 43A and 43B connected to the upper members 56A and 56B of the vertical frame portions 53A and 53B are displaced with the torsional deformation of the upper members 56A and 56B. Therefore, when the posture is such that it turns backward from one side in the width direction, the upper members 56A and 56B on one side are torsionally deformed, and the connecting pieces 43A and 43B on one side are displaced to stretch the back. Since it can be received so as to be wrapped together with the material, it can be stably supported in the state following the deformation on the back and shoulders of the seated person.

In this manner, the upper members 56A and 56B, the upholstery material 51, and the connecting pieces 43A and 43B of the vertical frame portions 53A and 53B follow the deformation of the seated person's back and shoulders, and these backs and The shoulder can be stably supported.

On the other hand, the lower members 57A, 57B of the vertical frame portions 53A, 53B together with the upholstery material 51 reliably support the waist around the seated person's back. Therefore, when taking the posture of turning from one side in the width direction to the rear, the lower members 57A and 57B can support the waist of the seated person together with the upholstery material 51.

Moreover, the upper parts of the rear arm portions 123 and 123 connected to the lower members 57A and 57B and the lower members 57A and 57B are inclined forward as they go upward. Therefore, the chair 101 reliably supports the seated person's load by suppressing the deformation of the lower members 57A and 57B and the rear arm portions 123 and 123 themselves. Further, since the lower members 57A and 57B and the rear arm portions 123 and 123 are prevented from deformation of the member itself, it is possible to maintain a state where they are firmly connected to each other.

Further, the operation procedure shown in the above-described embodiment, various shapes and combinations of the constituent members, etc. are examples, and various changes can be made based on design requirements and the like without departing from the gist of the present invention.

For example, in the embodiment described above, the backrest rear support member 40 and the backrest 50 are integrally formed, but the backrest rear support member 40 and the backrest 50 may be separate members. is there.

According to the above-described chair, when the seated person takes the action of tilting his back backward, the posture can be followed.

DESCRIPTION OF SYMBOLS 1,101 ... Chair 10 ... Legs 20, 120 ... Back support 40, 140 ... Back support member 41, 141 ... Lower connection part 42 ... Deformation allowance part 43 ... Upper connection part 43A, 43B ... A pair of connection Piece 50 ... Backrest 50A ... Backrest 51 ... Upholstery material 52 ... Upper frame portion 53A, 53B (53) ... Vertical frame portion 56A, 56B (56) ... Upper material 57A, 57B (57) ... Lower material 61 ... No. One annular part 62 ... second annular part

Claims (6)

1. Legs and
   A backrest supported by the leg;
   A backrest body supported by the backrest support body and supporting the back of the seated person,
   The back body is
   A flexible tension member that receives the back of the seated person and can be deformed in accordance with the back, and is attached to the tension member, and is separated in the width direction so as to be elastically deformable by a force acting on the tension member. A backrest having a pair of vertical frame portions,
   A backrest supporting member that connects the vertical frame portion in the vertical direction.
2. The backrest is supported by the backrest rear support member, supporting the back of the seated person,
   The back support member is supported by the back support;
   A lower connecting portion connected to the backrest support;
   A deformation allowing portion that extends upward from the lower connecting portion and is elastically deformable according to a load acting on the backrest from the back of the seated person;
   The chair according to claim 1, further comprising an upper connecting portion that extends upward from an upper end of the deformable portion and is connected to the backrest at the upper end.
3. The chair according to claim 2, wherein the upper connecting portion is formed so as to be gradually inclined forward as it goes upward.
4. The upper connecting portion has a pair of connecting pieces that are connected to the deformation-permitting portion at the lower end, are formed in a V shape so as to be separated from each other toward the upper side, and the upper end is connected to the backrest. The chair according to claim 2 or claim 3.
5. The vertical frame portion is
   A lower material formed such that the lower end is connected to the lower connection part and gradually tilts forward as it goes upward;
   3. An upper member that extends upward from the lower member and is inclined to the rear relative to the lower member as it goes upward, and is connected to the upper connecting portion at an upper end. The chair according to claim 4.
6. The chair according to claim 5, wherein the upholstery material has a lower part connected to the lower material and an upper part connected to the upper material.
   

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