JP2013132403A - Chair - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve various movements of a seat and a backrest without inviting increase of the number of components of a chair.SOLUTION: In a chair formed by making a leg body support a seat 4 through a tilting mechanism 6, the tilting mechanism 6 includes: a hard part 11 having an elastic deformation area elastically deformed when the load is applied to the seat 4; and a pair of opposed surfaces 113 provided within a thickness in the elastic deformation area of the hard part 11, to be brought closer accompanying the elastic deformation. When the hard part 11 is deformed to a prescribed elastic deformation limit, the opposed surfaces 113 are brought closer to each other, the elastic deformation characteristic of the hard part 11 is changed, and a configuration, such that the deformation exceeding the elastic deformation limit of the hard part 11 is suppressed, is adopted.

Description

  The present invention relates to a chair suitably used in an office or home.

  Conventionally, as a chair of this type, a back support member that supports the backrest is pivotally attached to a support base that is provided on the leg and supports the seat, and the backrest can be moved between the standing position and the backward tilt position. And a seat support or a seat frame that supports a seat on the support base, and a seat that is movable between a normal position and a rearward tilt position are known (for example, (See Patent Document 1).

  Here, in the conventional one, a pivot for pivotally attaching a back support member, a seat support, a seat frame and the like to the support base so that the seat and the backrest can be moved between the standing position and the backward tilt position. When the landing pin and these back support members, seat rests, stoppers for defining the movable range of the seat frame are provided separately, and when the backrest or seat is moved from the standing position to the rearward tilt position In order to supply reaction force, a coil spring, a torsion coil spring, and the like are further provided separately. Therefore, if the movement of the seat or the backrest is to be controlled at a high level, the number of parts tends to increase and the structure tends to be complicated, and some fundamental countermeasures are desired.

JP 2002-119357 A

  The present invention focuses on the above points, and an object thereof is to realize various seat and backrest movements without increasing the number of parts.

  That is, the chair according to the present invention is a chair having a leg that supports at least one of a seat and a backrest via a tilting mechanism, and the tilting mechanism applies a load to at least one of the seat and the backrest. Comprising a hard part having an elastic deformation region that elastically deforms when deformed, and a pair of opposing surfaces that are provided in the elastic deformation region of the hard part and approach each other in accordance with the elastic deformation. Then, when approaching a predetermined elastic deformation limit, the opposing surfaces come close to each other, and the elastic deformation characteristics of the hard part change, and the deformation of the hard part exceeding the elastic deformation limit is suppressed. Features.

  If this is the case, the function as a reaction force supply mechanism that has been realized by a conventional coil spring or torsion coil spring using the elastic deformation of the hard part, and the function that has been realized by a pivot pin, It can be realized with a simple structure by reducing the number of points. Moreover, the function as a stopper can be exhibited by the effect | action which the opposing surfaces adjoin and the elastic deformation characteristic of the said hard part changes, and the elastic deformation is suppressed. In the present invention, “proximity” is a concept including a case of direct contact and a case of approaching while elastically deforming an elastic material between opposing surfaces.

  As an example of a specific configuration for realizing such a chair, the tilting mechanism includes an elastic support provided between a support base supported by a leg and a seat. The part which changes the curvature degree according to the load which acts on the seat in an elastic support body as an elastic deformation area | region of the said hard part is mentioned.

  Further, as another example of a specific configuration for realizing such a chair, the tilting mechanism includes an elastic support provided between a support base supported by a leg and a backrest. In this elastic support, a portion where the degree of curvature changes according to the load acting on the backrest is used as the elastic deformation region of the hard portion.

  Furthermore, as another example of a specific configuration for realizing such a chair, the tilt mechanism includes an elastic support provided between a seat supported by a leg and a backrest. And a portion where the degree of curvature changes according to the load acting on the backrest of the elastic support is used as the elastic deformation region of the hard portion.

  In the present invention, “the degree of curvature changes” is a concept that includes all cases where the curvature changes, and includes an aspect in which the curvature is zero.

  In addition, as an example of a configuration for easily realizing such a hard portion, the hard portion includes a recessed portion that is opened outward, and a part of the inner side facing the recessed portion or The thing which all is the said opposing surface is mentioned.

  Furthermore, as a configuration for enabling adjustment of the elastic deformation of such a hard portion, a configuration in which an elastomer is disposed in the concave portion entirely or partially can be mentioned.

  As an example of an embodiment in which the recessed portion as described above is provided, the hard portion includes a thin portion, and a thick portion having a thickness dimension larger than that of the thin portion provided on both sides of the thin portion, The thing in which the said recessed part is formed between the said both thick parts is mentioned.

  According to the present invention, the number of parts can be reduced, and various seating and backrest movements can be realized with a simple structure.

The whole perspective view showing the chair of a 1st embodiment of the present invention. The right view which shows the chair of the embodiment. The principal part enlarged view in FIG. Operation | movement explanatory drawing which shows the action | operation of the chair of the embodiment. The right view which shows the chair of 2nd Embodiment of this invention. The figure which expands and shows the principal part in FIG. The right view which shows the chair of 3rd Embodiment of this invention. The right view which shows the chair of 4th Embodiment of this invention. The figure which expands and shows the principal part in FIG. The right view which shows the chair of 5th Embodiment of this invention. The figure which expands and shows the principal part in FIG. The figure which shows the modification of the recessed part of this invention typically. The figure which shows the modification of the recessed part of this invention typically. The figure which shows the modification of the recessed part of this invention typically. The figure which shows the modification of the recessed part of this invention typically. The figure which shows the modification of the recessed part of this invention typically. The figure which shows the modification of the recessed part of this invention typically. The figure which shows the modification of the recessed part of this invention typically. The bottom view of the modification. The figure which shows the modification of the recessed part of this invention typically. The figure which shows typically the modified part of the recessed part and elastomer of this invention. The figure which shows typically the modified part of the recessed part and elastomer of this invention. The figure which shows typically the modified part of the recessed part and elastomer of this invention. The figure which shows the modification of the recessed part of this invention typically. The action explanatory view of the modification. The figure which shows the modification of the recessed part of this invention typically.

  First, a first embodiment of the present invention will be described with reference to FIGS.

  In this embodiment, the present invention is applied to an office swivel chair. As shown in FIGS. 1 and 2, the chair 1 includes a leg body 2, a seat 4 supported by the leg body 2 via a support mechanism 3, and a backrest 5 disposed above and behind the seat 4. It comprises.

  As shown in FIGS. 1 and 2, the leg body 2 includes a leg blade 21 having a caster 23 attached to the tip thereof and a leg column 22 erected from the leg blade 21. The leg strut 22 is constituted by a gas spring, and a seat 4 is arranged above the cylinder shaft (not shown) of the gas spring via a support mechanism 3.

  As shown in FIGS. 1 to 3, the support mechanism 3 includes a support base 31 attached to the upper end of the cylinder shaft of the leg 2, and a fixed arm 32 erected upward from the left and right ends of the support base 31. The left and right curved support bodies 33 support the seat 4 at the front end 33a and support the base end 33b on the support base 31 so that they can turn in the horizontal direction together with the cylinder shaft. It has become. Left and right support shafts 321 are provided at the upper ends of the left and right fixed arms 32 so that their axis centers coincide with each other, and the seat 4 is supported by the support shafts 321 so as to be capable of performing a balance operation. Here, the “balance operation” refers to an operation about the support shaft 321 as the center, when the seated person's load is applied rearward, the seat 4 tilts backward, the rear end side is lowered, and the front end side is raised. In the present embodiment, the balance operation includes an operation in which the seat 4 returns to the initial state when the load of the seated person is applied forward with the support shaft 321 as the center, the front end side is lowered and the rear end side is raised. Yes. The axis extends in the left-right direction of the chair 1. The left and right curved supports 33 are made of a band-like hard synthetic resin in this embodiment.

  As shown in FIGS. 1 and 2, the seat 4 is obtained by stretching a mesh-like tension fabric 42 between the left and right seat frames 41. The seat 4 includes a front region F on the front side of the axis and a rear region R on the rear side of the axis. Further, the seat frame 41 is made of a hard synthetic resin, and continuously and integrally extends rearward from the tip 33a of the curved support 33. A movable arm 411 is integrally provided on an intermediate lower surface of the seat frame 41. The tip of the movable arm 411 is pivotally supported by the fixed arm 32 via the support shaft 321 so as to be rotatable in the front-rear direction.

  As shown in FIGS. 1 and 2, the backrest 5 is formed by stretching a mesh-like tension fabric 52 between the left and right back frames 51 formed integrally with the left and right seat frames 41. The left and right seat frames 41, the left and right back frames 51, and the curved support body 33 are each integrally formed of, for example, a hard synthetic resin reinforced with fibers. The left and right back frames 51 are connected by a horizontal member 53. The horizontal member 53 has elasticity that allows the left and right back frames 51 to tilt at different angles. In other words, when the left and right back frames 51 are tilted at different angles, the horizontal member 53 can accumulate elastic force while being bent while being twisted. The chair 1 according to this embodiment is configured such that the backrest 5 and the seat 4 are interlocked. Specifically, the seat 4 is tilted in accordance with the backward tilting operation of the backrest 5 while the front side is raised. It is a weight-sensing type that can be moved.

  In such a chair, a tilting mechanism 6 is provided between the support base 3 supported by the leg 2 and the seat 4. The tilt mechanism 6 includes an elastic support 61 that supports the seat 4 at the distal end portion while supporting the base end portion on the support base portion 3. More specifically, the elastic support 61 includes a hard portion 11 that is elastically deformed when a load is applied, and a surface on the side that receives compressive stress due to the elastic deformation of the hard portion 11, that is, a rearward surface 611. When two hardened portions 11 are deformed up to a predetermined elastic deformation limit, two concave portions 112 are formed on the inner surface of the concave portions 112. A pair of opposing surfaces 113 are formed on the inner side of the recessed portions 112. The opposing surfaces 113 are in direct contact with each other so that the elastic deformation characteristics of the hard portion 11 are greatly changed, and deformation of the hard portion 11 beyond the elastic deformation limit is suppressed. That is, a portion of the elastic support 61 whose degree of curvature changes according to the load acting on the seat 3 is set as an elastic deformation region of the hard portion 11, and the concave portion 112 is provided in the elastic deformation region. In this embodiment, a plurality of recessed portions 112 are formed on the rearward surface 611 of the elastic support member 61, that is, the outer surface 111 of the hard portion 11 with a space in the vertical direction, and the elastomer 12 is formed on a part of each of the recessed portions 112. Is filled. The recessed portion 112 is open to the outer surface 111 of the hard portion 11 and both side surfaces 117 continuous to the outer surface 111, and a part of the inner side of the recessed portion 112 that faces is used as the facing surface 113. In other words, the recessed portion 112 has a larger opening width on the back side than the opening width on the opening end side. The inner side of the opening end side serves as the facing surface 113, and the elastomer 12 is formed on the back side. Filled. In other words, the hard portion 11 includes a thin portion 91 and thick portions 92 that are provided on both sides of the thin portion 91 and have a thickness dimension larger than that of the thin portion 91. The recessed portion 112 is formed between the portions 92.

  In such a chair 1, when sitting on the seat 4 in the office posture S, the load caused by the weight of the seated person acts on the front region F of the seat 4, so that the left and right seat frames 41 tilt. Instead, the seat 4 is supported in a stable state as shown by the solid line in FIG. 2 and FIG. Further, when the seated person leans on the backrest 5 and the load shifts to the rear region R of the seat 4, the left and right seat frames 41 operate as a balance, and as shown in the imaginary line of FIG. 2 and FIG. 4 rear region R will sink. At this time, the vicinity of the distal ends 33a of the left and right curved supports 33 moves upward in conjunction with the seat 4, and the vicinity of the base ends 33b of the left and right curved supports 33 is fixed to the support base 31. As shown in the imaginary line of FIG. 2 and FIG. 4, the left and right curved supports 33 are elastically deformed, and the upward surface 331 in the vicinity of the base end 33b receives compressive stress. At that time, the left and right elastic supports 61 receive a load from the seat 4 and elastically deform in a direction in which the degree of curvature increases. As a result, until the hard part 11 reaches the elastic deformation limit, the space 113 between the opposing surfaces of the recessed parts 112 approaches. Furthermore, when the hard part 11 reaches the elastic deformation limit, the opposing surfaces 113 of the recessed parts 112 come into contact with each other. Therefore, further elastic deformation of the elastic support 61 is suppressed, and further sinking of the rear portion of the seat 4 is suppressed. In addition, in this embodiment, the left and right elastic supports 61 are provided with a plurality of recessed portions 112, respectively, and when the hard portion 11 is deformed to a predetermined elastic deformation limit, the opposing surface 113 of each recessed portion 112 is provided. Since they are in contact with each other to prevent deformation of the hard part 11 beyond the elastic deformation limit, the elastic support 61 is deformed in advance with the opposing surfaces 113 in contact with each other. Keep in shape. When the seated person returns to the working position S from the position leaning on the backrest 5, the force due to the weight of the seated person and the elastic repulsive force accumulated in the curved support body 33 and the elastic support body 61 are used. The seat 4 and the backrest 5 return to the initial position shown in the solid line of FIG. 2 and FIG.

  As described above, according to the configuration according to the present embodiment, when the seat 2 is supported by the leg 2 via the tilt mechanism 6, and the load is applied to the seat 4, the tilt mechanism 6 applies a load. A hard portion 11 having an elastic deformation region that elastically deforms, and a pair of opposing surfaces 113 that are provided in the elastic deformation region of the hard portion 11 and approach each other in accordance with the elastic deformation. Are deformed up to a predetermined elastic deformation limit, the opposing surfaces 113 come into contact with each other, and the elastic deformation characteristics of the hard portion 11 are greatly changed to prevent deformation of the hard portion 11 beyond the elastic deformation limit. Therefore, the facing surface 113 functions as a stopper, and these functions can be realized without providing a special reaction force mechanism or stopper.

  Further, the tilt mechanism 6 includes an elastic support 61 provided between the support base 3 supported by the leg 2 and the seat 4, and acts on the seat 4 in the elastic support 61. Since the region where the degree of curvature changes according to the load is used as the elastic deformation region of the hard portion 11, the elastic support 61 can be arranged by effectively using the space between the support base 3 and the seat 4. The appearance of the chair 1 can be adjusted by forming the elastic support 61 so that the support base 3 and the seat 4 are smoothly connected.

  Further, since the hard portion 11 includes a recessed portion 112 that is opened outward, and a part of the opposed inner portion of the recessed portion 112 is the facing surface 113, the hard portion having such a facing surface 113. The part 11 can be easily realized.

  In addition, since the elastomer 12 is disposed in the recessed portion 112, the elastic deformation state of the hard portion can be adjusted by attaching and detaching the elastomer 12 or exchanging the elastomer 12 with a different one.

  The hard portion 11 includes a thin portion 91 and thick portions 92 that are provided on both sides of the thin portion 91 and have a thickness dimension larger than that of the thin portion 91. Since the recessed portion 112 is formed between them, the recessed portion 112 can be arranged without difficulty.

  Next, a second embodiment of the present invention will be described with reference to FIGS.

  In this embodiment, the present invention is applied to an office swivel chair. As shown in FIGS. 5 and 6, the chair 1 includes a leg body 2, a seat 4 supported by the leg body 2 via a support mechanism 3, and a backrest 5 disposed above and behind the seat. It comprises.

  As shown in FIG. 5, the leg body 2 includes a leg blade 21 having a caster 23 attached to the tip thereof, and a leg column 22 erected from the leg blade 21. The leg strut 22 is constituted by a gas spring, and a seat 4 is arranged above the cylinder shaft (not shown) of the gas spring via a support mechanism 3.

  As shown in FIGS. 5 and 6, the support mechanism 3 supports the seat 4 with a support base 31 attached to the upper end of the cylinder shaft of the leg 2 and a tip 33a and supports the base 33b. It comprises a curved support 33 supported by a base 31 and can turn in the horizontal direction together with the cylinder shaft. In the present embodiment, the curved support 33 is made of a shell-like hard synthetic resin.

  As shown in FIGS. 5 and 6, the seat 4 includes a seat shell 41, a seat cushion 42 provided on the seat shell 41, and a tension fabric 43 that covers the seat cushion 42.

  As shown in FIGS. 5 and 6, the backrest 5 includes a back shell 51, a back cushion (not shown) provided on the front surface of the back shell, and a tension fabric (not shown) that covers the back cushion.

  Here, the curved support portion 33, the seat shell 41, and the back shell 51 are integrally formed of synthetic resin.

  In such a chair, a tilting mechanism 6 is provided between the support base 31 supported by the leg 2 and the seat 4. The tilting mechanism 6 includes an elastic support 61 that supports the seat 4 at the distal end portion while supporting the base end portion on the support base portion 31. More specifically, the elastic support 61 includes a hard portion 11 that is elastically deformed when a load is applied, and a surface on the side that receives compressive stress due to the elastic deformation of the hard portion 11, that is, a rearward surface 611. When two hardened portions 11 are deformed up to a predetermined elastic deformation limit, two concave portions 112 are formed on the inner surface of the concave portions 112. A pair of opposing surfaces 113 are formed on the inner side of the recessed portions 112. The opposing surfaces 113 are in direct contact with each other so that the elastic deformation characteristics of the hard portion 11 are greatly changed, and deformation of the hard portion 11 beyond the elastic deformation limit is suppressed. That is, the portion of the elastic support 61 whose degree of curvature changes according to the load acting on the seat 4 is defined as an elastic deformation region of the hard portion 11, and the concave portion 112 is provided in the elastic deformation region. In this embodiment, a plurality of recessed portions 112 are formed on the rearward surface 611 of the elastic support member 61, that is, the outer surface 111 of the hard portion 11 with a space in the vertical direction, and the elastomer 12 is formed on a part of each of the recessed portions 112. Is filled. The recessed portion 112 is open to the outer surface 111 of the hard portion 11 and both side surfaces 117 continuous to the outer surface 111, and a part of the inner side of the recessed portion 112 that faces is used as the facing surface 113. In other words, the recessed portion 112 has a larger opening width on the back side than the opening width on the opening end side. The inner side of the opening end side serves as the facing surface 113, and the elastomer 12 is formed on the back side. Filled. In other words, the hard portion 11 includes a thin portion 91 and thick portions 92 that are provided on both sides of the thin portion 91 and have a thickness dimension larger than that of the thin portion 91. The recessed portion 112 is formed between the portions 92.

  According to the structure which concerns on this embodiment, although the effect | action similar to a chair is performed to 1st Embodiment mentioned above, Furthermore, the curved support body 33, the seat shell 41, and the back shell 51 are integrally formed with the synthetic resin. Therefore, the number of parts is small and a simple structure can be achieved.

  Next, a third embodiment of the present invention will be described with reference to FIG.

  In this embodiment, the present invention is applied to an office swivel chair. As shown in FIG. 7, the chair 1 includes a leg body 2, a seat 4 supported by the leg body 2 via a support mechanism 3, and a backrest 5 disposed above and behind the seat 4. Do it.

  As shown in FIG. 7, the leg body 2 includes a leg blade 21 having a caster 23 attached to the tip thereof and a leg column 22 erected from the leg blade 21. The leg strut 22 is constituted by a gas spring, and a seat 4 is arranged above the cylinder shaft (not shown) of the gas spring via a support mechanism 3.

  As shown in FIG. 7, the support mechanism 3 includes a support base 31 attached to the upper end of the cylinder shaft of the leg 2, a fixed arm 32 erected upward from the left and right ends of the support base 31, and a tip. It comprises a left and right curved support 33 that supports the seat 4 and has a base end supported by the support base 31, and can turn in the horizontal direction together with the cylinder shaft. Left and right support shafts 321 are provided at the upper ends of the left and right fixed arms 32 so that their axis centers coincide with each other, and the seat 4 is supported by the support shafts 321 so as to be capable of performing a balance operation. In the present embodiment, the balance operation includes an operation in which the seat 4 returns to the initial state when the load of the seated person is applied forward with the support shaft 321 as the center, the front end side is lowered and the rear end side is raised. Yes. The shaft center 321 extends in the left-right direction of the chair 1. The left and right curved supports 33 are made of a band-like hard synthetic resin in this embodiment.

  As shown in FIG. 7, the seat 4 is obtained by stretching a mesh-like tension fabric 42 between the left and right seat frames 41. The seat 4 includes a front region F on the front side of the axis 321 and a rear region R on the rear side of the axis. Further, the seat frame 41 is made of a hard synthetic resin, and continuously extends rearward from the distal end of the curved support 33. A movable arm 411 is integrally provided on an intermediate lower surface of the seat frame 41. The tip of the movable arm 411 is pivotally supported by the fixed arm 32 via the support shaft 321 so as to be rotatable in the front-rear direction.

  As shown in FIG. 7, the backrest 5 is obtained by stretching a mesh-like tension fabric 52 between the left and right back frames 51 formed integrally with the left and right seat frames 41. The left and right seat frames 41, the left and right back frames 51, and the curved support body 33 are each integrally formed of, for example, a hard synthetic resin reinforced with fibers. The left and right back frames 51 are connected by a horizontal member 53. The horizontal member 53 has elasticity that allows the left and right back frames 51 to tilt at different angles. In other words, when the left and right back frames 51 are tilted at different angles, the horizontal member 53 can accumulate elastic force while being bent while being twisted. The chair 1 according to this embodiment is configured such that the backrest 5 and the seat 4 are interlocked. Specifically, the seat 4 is tilted in accordance with the backward tilting operation of the backrest 5 while the front side is raised. It is a weight-sensing type that can be moved.

  In such a chair, a tilting mechanism 6 is provided between the seat 4 supported by the leg 2 and the backrest 5. The tilting mechanism 6 includes an elastic support body 61 provided between the seat 4 supported by the leg body 2 and the backrest 5. Specifically, as shown in FIG. 7, the elastic support 61 is made of a synthetic resin that integrally connects the seat frame 41 and the back frame 51, and is a hard material that is elastically deformed when a load is applied. The concave portion 112 is provided on a surface on the side subjected to compressive stress due to elastic deformation of the hard portion 11, that is, the downward surface 611, and approaches the inside of the concave portion 112 along with the elastic deformation. A pair of opposing surfaces 113 are formed, and when the hard portion 11 is deformed to a predetermined elastic deformation limit, the opposing surfaces 113 are in direct contact with each other, and the elastic deformation characteristics of the hard portion 11 change, and the hard portion 11 is designed to suppress deformation exceeding the elastic deformation limit. That is, a portion where the degree of curvature changes according to the load acting on the backrest 5 in the elastic support 61 is set as an elastic deformation region of the hard portion 11, and the concave portion 112 is provided in the elastic deformation region. In this embodiment, a concave portion 112 is formed on the downward surface 611 of the elastic support 61, that is, the outer surface 111 of the hard portion 11, and a part of the concave portion 112 is filled with the elastomer 12. The recessed portion 112 is open to the outer surface 111 of the hard portion 11 and both side surfaces 117 continuous to the outer surface 111, and a part of the inner side of the recessed portion 112 that faces is used as the facing surface 113. In other words, the recessed portion 112 has a larger opening width on the back side than the opening width on the opening end side. The inner side of the opening end side serves as the facing surface 113, and the elastomer 12 is formed on the back side. Filled. In other words, the hard portion 11 includes a thin portion 91 and thick portions 92 that are provided on both sides of the thin portion 91 and have a thickness dimension larger than that of the thin portion 91. The recessed portion 112 is formed between the portions 92. In this embodiment, the elastic support 61 is composed of a hard portion 11 formed of a hard synthetic resin and the elastomer 112.

  In the case of such a chair 1, when sitting on the seat 4 in the office posture S, the load caused by the weight of the seated person acts on the front region F of the seat 4, so that the left and right seat frames 41 tilt. Instead, the seat 4 is supported in a stable state. Further, when the seated person sits rearward and the load shifts to the rear region R of the seat 4, the left and right seat frames 41 move in a balance manner, and the rear region R of the seat 4 sinks. At this time, the vicinity of the distal ends 33a of the left and right curved supports 33 moves upward in conjunction with the seat 4, and the vicinity of the base ends 33b of the left and right curved supports 33 is fixed to the support base 31. As shown in the figure, the left and right curved supports 33 are elastically deformed.

  When the seated person leans on the backrest 5, the left and right elastic supports 61 receive a load from the backrest 5 and elastically deform in a direction in which the degree of curvature decreases. This elastic deformation is mainly governed by the elastic characteristics of the thin-walled portion 91 and accumulates repulsive force until the opposing surfaces 113 of the recessed portion 112 contact each other, but after the opposing surfaces 113 contact each other. Therefore, the deformation of the thin portion 91 is prohibited, and the elastic property of the thick portion 92 is controlled. That is, the elastic deformation characteristics of the hard portion 11 change suddenly before and after the opposing surfaces 113 come into contact with each other, and after the opposing surface 113 comes into contact, the backrest 5 is restrained from being further inclined backward. The In other words, until the hard portion 11 that forms the main body of the elastic support 61 reaches the elastic deformation limit, the thin-walled portion 91 is mainly deformed and the opposing surfaces 113 of the recessed portion 112 approach each other. Furthermore, when the hard part 11 reaches the elastic deformation limit, the opposing surfaces 113 of the recessed part 112 come into contact with each other. Therefore, further elastic deformation of the elastic support 61 is suppressed, and the backward tilting operation of the backrest 5 is suppressed. Even after the hard part 11 reaches the elastic deformation limit and the opposing surfaces 113 come into contact with each other, the elastic support body 61 is fixed to the hard part 11 by applying an excessive backward tilting force to the backrest 5. Some elastic deformation is induced while being controlled by the elastic characteristics of the thick-walled portion 92. In addition, in this embodiment, the left and right elastic supports 61 are provided with recessed portions 112, respectively, and when the hard portion 11 is deformed to a predetermined elastic deformation limit, the opposing surfaces 113 of the recessed portions 112 are in contact with each other. Since the hard part 11 is prevented from being deformed beyond the elastic deformation limit, the elastic support member 61 is in a state where the opposing surfaces 113 are in contact with each other unless an excessive force is applied. Is maintained in a preset deformed shape.

  When the seated person returns to the working position S from the position leaning on the backrest 5, the force due to the weight of the seated person and the elastic repulsive force accumulated in the curved support body 33 and the elastic support body 61 are used. The seat 4 and the backrest 5 return to the initial posture shown in FIG.

  As described above, even with the configuration according to the present embodiment, the main effect of the configuration according to the chair of the first embodiment described above, that is, the tilting mechanism 6 is provided in the hard portion 11 and the hard portion 11. A pair of opposing surfaces 113 that approach each other with elastic deformation, and when the hard portion 11 is deformed to a predetermined elastic deformation limit, the opposing surfaces 113 come close to each other and elastic deformation of the hard portion 11 occurs. The opposing surface 113 functions as a stopper by suppressing the deformation of the hard part 11 exceeding the elastic deformation limit, so that these functions can be realized without providing a special reaction mechanism or stopper. The effect that it can be obtained.

  The tilting mechanism 6 includes an elastic support 61 provided between the seat 4 supported by the leg 2 and the backrest 5, and acts on the seat 4 in the elastic support 61. Since the region where the degree of curvature changes according to the load is used as the elastic deformation region of the hard portion 11, this type of connecting the seat frame 41 and the back frame 51 integrally through the elastic support 61 made of synthetic resin. In the chair, the effects described in the previous stage can be obtained with a simple configuration.

  Furthermore, since the elastomer 12 is disposed in the recessed portion 112, the elastic deformation state of the hard portion 11 can be adjusted by attaching and detaching the elastomer 12 or exchanging the elastomer 12 with a different one.

  In addition, the hard portion 11 includes a thin portion 91 and a thick portion 92 that is provided on both sides of the thin portion 91 and has a thickness dimension larger than that of the thin portion 91. Since the recessed portion 112 is formed between 92, such a recessed portion 112 can be arranged without difficulty.

  Next, a fourth embodiment of the present invention will be described with reference to the drawings.

  In this embodiment, the present invention is applied to an office swivel chair. As shown in FIGS. 8 and 9, the chair 1 includes a leg body 2, a seat 4 supported by the leg body 2 through a support mechanism 3, and a backrest 5 provided separately from the seat 4. It comprises.

  As shown in FIG. 8, the leg body 2 includes a leg blade 21 having a caster attached to the tip, and a leg column 22 erected from the leg blade 21. The leg strut 22 is constituted by a gas spring, and a seat 4 is arranged above the cylinder shaft (not shown) of the gas spring via a support mechanism 3.

  As shown in FIGS. 8 and 9, the support mechanism 3 includes a support base 31 provided on the leg support 22, and a front link element 34 that forms a left-right pair provided at the front end of the support base 31. A pair of left and right rear link elements 36 provided at the rear end of the support base 31, and a back support member 37 extending rearward from the support base 31 and extending the front end to the front side of the backrest 5. And a seat receiver 38 connected to the upper end portion of the front link element 34 and the upper end portion of the rear link element 36. Here, the support base 31, the front link element 34, the rear link element 36, the back support member 37, and the seat support 38 are integrally formed of a hard synthetic resin. That is, the front link element 34 is a bowl-shaped body mainly composed of the hard portion 11, and is a surface on the side that receives compressive stress due to elastic deformation accompanying the standing of the hard portion 11, that is, a rearward surface 241 in the vicinity of the proximal end and A concave portion 112 is provided on the forward-facing surface 342 in the vicinity of the tip, and a pair of opposing surfaces 113 are formed on the inner side of the concave portion 112 so as to approach with the elastic deformation. The elastomer 12 is disposed on a part of the recessed portion 112. When the hard part 11 is deformed, the elastic deformation characteristic of the elastomer 12 is gradually changed while the elastomer 12 is deformed. Further, when the opposed surfaces 113 are in direct contact with each other, the elastic deformation characteristic of the hard part 11 is changed. Is greatly changed, so that deformation of the hard portion 11 exceeding a predetermined elastic deformation limit is suppressed. The rear link element 36 is also a bowl-shaped body mainly composed of the hard portion 11, and is a surface on the side receiving compressive stress due to elastic deformation accompanying the standing of the hard portion 11, that is, the rearward surface 361 near the proximal end and the vicinity of the distal end. A concave portion 112 is provided on the forward-facing surface 362, and a pair of opposing surfaces 113 are formed inside the concave portion 112 so as to approach each other with the elastic deformation. The elastomer 12 is disposed on a part of the recessed portion 112. When the hard part 11 is deformed, the elastic deformation characteristic of the elastomer 12 is gradually changed while the elastomer 12 is deformed. Further, when the opposed surfaces 113 are in direct contact with each other, the elastic deformation characteristic of the hard part 11 is changed. Is greatly changed, so that deformation of the hard portion 11 exceeding a predetermined elastic deformation limit is suppressed. The back support member 37 is also a bowl-shaped member mainly composed of the hard portion 11, and a concave portion is formed on the surface on the side receiving compressive stress due to the elastic deformation of the hard portion 11 backward, that is, the downward surface 371 in the vicinity of the base end. 112 is provided, and a facing surface 113 is formed on the inner side of the recessed portion 112 to form a pair approaching with the elastic deformation. The elastomer 12 is disposed on a part of the recessed portion 112. When the hard part 11 is deformed, the elastic deformation characteristic of the elastomer 12 is gradually changed while the elastomer 12 is deformed. Further, when the opposed surfaces 113 are in direct contact with each other, the elastic deformation characteristic of the hard part 11 is changed. Is greatly changed, so that deformation of the hard portion 11 exceeding a predetermined elastic deformation limit is suppressed. The recessed portion 112 is open to the outer surface 111 of the hard portion 11 and both side surfaces 117 continuous to the outer surface 111, and a part of the inner side of the recessed portion 112 that faces is used as the facing surface 113. The recessed portion 112 has a larger opening width on the back side than the opening width on the opening end side, and the inner side on the opening end side serves as the facing surface. In other words, the hard portion 11 of the front link element 34 and the hard portion 11 of the rear link element 36 are respectively provided with a thin portion 91 and on both sides of the thin portion 91 and have a thickness dimension larger than that of the thin portion 91. A large thick portion 92 is provided, and the concave portion 112 is formed between the thick portions 92. Further, the elastomer 12 is disposed in a portion where the opening width on the back side of the recessed portion 112 is set large. The front link element 34 can be rotated backward with respect to the support base 31 with the vicinity of the thin portion 91 as a pseudo pivot point, and can be rotated forward with respect to the seat frame 38. I am doing so. The rear link element 36 can be rotated rearward with respect to the support base 31 with the vicinity of the thin-walled portion 91 as a pseudo pivot point, and can also be rotated forward with respect to the seat frame 38. I am doing so. The back support member 37 is also configured to be able to rotate rearward with respect to the support base 31 with the vicinity of the thin portion 91 as a pseudo pivot point. The seat receiver 38 has a frame shape and supports a seat on the upper surface. The seat receiver body 381 extends rearward from the rear end of the seat receiver body 381 and connects to the back support member 37 at the extended end. Have The support base 31, the front link element 34, the seat receiver 38, and the rear link element 36 are configured to perform an operation according to a four-bar linkage mechanism.

  As shown in FIGS. 8 and 9, the seat 4 includes a shell (not shown) disposed above the seat receiver 38, a seat cushion 43 provided on the shell, and a tension fabric 42 covering the seat cushion 43. It is formed using.

  As shown in FIG. 8, the backrest 5 includes a shell (not shown) disposed on the front surface of the upper portion of the back support member 37, a back cushion 53 provided in front of the shell, and a tension fabric 52 covering the back cushion 53. It is formed using and.

  In the chair as described above, the tilting mechanism 6 for allowing the backrest 5 to tilt backward with respect to the support base 31 is provided. The tilting mechanism 6 is mainly composed of a back support member 37 that is an elastic support, and the back support member 37 is interposed between a support base 31 supported by the leg 2 and the backrest 5. Is provided. The back support member 37 is mainly composed of a hard portion 11 made of a hard synthetic resin, and a portion where the degree of curvature changes according to a load acting on the backrest 5 is an elastic deformation region of the hard portion 11. It is said.

  According to the present embodiment, the recessed portions 112 are provided on the rear facing surfaces 341 and 361 in the vicinity of the proximal ends of the front link element 34 and the rear link element 36 and the front facing surfaces 342 and 362 in the vicinity of the distal end, and the inner sides of the recessed portions 112 facing each other. When the front link element 34 and the rear link element 36 are deformed and approach a predetermined elastic deformation limit, the opposed surfaces 113 are close to each other, and the elastic deformation characteristics of the hard portion 11 are large. By changing, the deformation of the hard portion 11 exceeding the elastic deformation limit is suppressed. Therefore, although the front link element 34 and the rear link element 36 are integrally formed with the support base 31 and the seat receiver 38, the support base 31, the front link element 34, the seat receiver 38, and the rear link are formed. The operation according to the four-bar linkage mechanism can be realized by the element 36. For this purpose, the lower end portions of the front link element 34 and the rear link element 36 are pivotally attached to the support base 31 and the upper end portions of the front link element 34 and the rear link element 36 are compared to those that are pivotally attached to the seat 38. Thus, the number of parts can be reduced. Moreover, since the front link element 34 and the rear link element 36 do not tilt backward more than a certain amount, a special stopper for restricting the rear link element 34 and the rear link element 36 from rotating backward is unnecessary. Become. In addition, a recessed portion 112 is provided on the downward surface 371 at the base end portion of the back support member 37, and a part of the opposed inside of the recessed portion 112 serves as the facing surface 113, and the back support member 37 is deformed to have a predetermined When the elastic deformation limit is approached, the opposing surfaces 113 come close to each other, and the elastic deformation characteristics of the hard portion 11 are greatly changed, so that the deformation of the hard portion 11 exceeding the elastic deformation limit is suppressed. Therefore, the number of parts can be reduced as compared with the case where the back support member 37 is pivotally attached to the support base 31 via the shaft.

  In addition, since the elastomer 12 is disposed in the recessed portion 112, the elastic deformation of the hard portion 11 can be adjusted by attaching and detaching or replacing the elastomer 12.

  In addition, the hard portion 11 includes a thin portion 91 and a thick portion 92 that is provided on both sides of the thin portion 91 and has a thickness dimension larger than that of the thin portion 91. Since the recessed portion 112 is formed between 92, such a recessed portion 112 can be arranged without difficulty.

  Next, a fifth embodiment of the present invention will be described with reference to the drawings.

  In this embodiment, the present invention is applied to an office swivel chair. As shown in FIGS. 10 and 11, the chair 1 includes a leg body 2, a seat 4 supported by the leg body 2 via a support mechanism 3, and a backrest 5 provided separately from the seat 4. It comprises.

  As shown in FIG. 10, the leg body 2 includes a leg blade 21 having a caster 23 attached to the tip thereof, and a leg column 22 erected from the leg blade 21. The leg strut 22 is constituted by a gas spring, and a seat 4 is arranged above the cylinder shaft (not shown) of the gas spring via a support mechanism 3.

  As shown in FIGS. 10 and 11, the support mechanism 3 includes a support base 31 provided on the leg strut 2 and a front link element 34 that forms a left-right pair provided at the front end of the support base 31. A back support member 37 extending rearward from the support base 31 and having a leading end extended to the front side of the backrest 5; a front end connected to the upper end of the front link element 34; and a rear end And a seat support 38 connected to the back support member 37. Here, the support base 31, the front link element 34, the back support member 37, and the seat receiver 38 are integrally formed of a hard synthetic resin. That is, the front link element 34 is a bowl-shaped body mainly composed of the hard portion 11, and the surface on the side that receives compressive stress due to the elastic deformation of the hard portion 11, that is, the rearward surface 341 near the proximal end and the vicinity of the distal end. A concave portion 112 is provided on the forward-facing surface 342, and a facing surface 113 is formed inside the concave portion 112, which forms a pair that approaches with the elastic deformation. The elastomer 12 is disposed on a part of the recessed portion 112. When the hard part 11 is deformed, the elastic deformation characteristic of the elastomer 12 is gradually changed while the elastomer 12 is deformed. Further, when the opposed surfaces 113 are in direct contact with each other, the elastic deformation characteristic of the hard part 11 is changed. Is greatly changed, so that deformation of the hard portion 11 exceeding a predetermined elastic deformation limit is suppressed. The back support member 37 is a bowl-shaped member mainly composed of the hard portion 11, and a concave portion is formed on a surface on the side receiving compressive stress by elastic deformation of the hard portion 11 backward, that is, a downward surface 371 in the vicinity of the base end. 112 is provided, and a facing surface 113 is formed on the inner side of the recessed portion 112 to form a pair approaching with the elastic deformation. The elastomer 12 is disposed on a part of the recessed portion 112. When the hard part 11 is deformed, the elastic deformation characteristic of the elastomer 12 is gradually changed while the elastomer 12 is deformed. Further, when the opposed surfaces 113 are in direct contact with each other, the elastic deformation characteristic of the hard part 11 is changed. Is greatly changed, so that deformation of the hard portion 11 exceeding a predetermined elastic deformation limit is suppressed. The seat receiver 38 has a frame shape and a seat receiving body 381 that supports the seat on the upper surface, and a connecting portion 382 that extends backward from the rear end of the seat receiving body 381 and connects to the back support member at the extended end. Have. The seat receiving body 381 and the connecting portion 382 are mainly composed of the hard portion 11, and the concave portion 112 is formed on the surface of the connecting portion 382 that receives compressive stress due to the elastic deformation of the hard portion 11, that is, the forward-facing surface 383. The opposing surface 113 which makes the pair approaching with the said elastic deformation is formed inside this recessed part 112. As shown in FIG. The elastomer 12 is disposed on a part of the recessed portion 112. When the hard part 11 is deformed, the elastic deformation characteristic of the elastomer 12 is gradually changed while the elastomer 12 is deformed. Further, when the opposed surfaces 113 are in direct contact with each other, the elastic deformation characteristic of the hard part 11 is changed. Is greatly changed, so that deformation of the hard portion 11 exceeding a predetermined elastic deformation limit is suppressed. The recessed portion 112 is open to the outer surface 111 of the hard portion 11 and both side surfaces 117 continuous to the outer surface 111, and a part of the inner side of the recessed portion 112 that faces is used as the facing surface 113. In other words, the recessed portion 112 has a larger opening width on the back side than the opening width on the opening end side, and the inner side on the opening end side serves as the facing surface 113. In other words, the hard portion 11 of the front link element 34 and the hard portion 11 of the back support portion 37 are respectively provided with a thin portion 91 and on both sides of the thin portion 91, and the thickness dimension is larger than the thin portion 91. The thick-walled portion 92 is provided, and the recessed portion 112 is formed between the thick-walled portions 92. The front link element 34 and the back support member 37 are configured to be able to rotate rearward with respect to the support base 31 with the vicinity of the thin wall portion as a pseudo pivot point and forward with respect to the seat support 38. It can be rotated. Further, the seat receiver 38 has an angle formed between the seat support body 381 and the back support member 37 in conjunction with a change in the angle of the back support member 37 with respect to the support base 31 using the vicinity of the thin portion 91 as a pseudo pivot point. It is possible to change.

  As shown in FIGS. 10 and 11, the seat 4 includes a shell (not shown) disposed above the seat receiver 38, a seat cushion 43 provided on the shell, and a tension fabric 42 covering the seat cushion 43. It is formed using.

  As shown in FIG. 11, the backrest 5 includes a shell (not shown) arranged on the front surface of the upper portion of the back support member 37, a back cushion 53 provided in front of the shell, and a tension fabric 52 covering the back cushion 53. It is formed using and.

  In the chair as described above, the tilting mechanism 6 for allowing the backrest 5 to tilt backward with respect to the support base 31 is provided. The tilting mechanism 6 is mainly composed of a back support member 37 that is an elastic support, and the back support member 37 is interposed between a support base 31 supported by the leg 2 and the backrest 5. Is provided. The back support member 37 is mainly composed of a hard portion 11 made of a hard synthetic resin, and a portion where the degree of curvature changes according to a load acting on the backrest 5 is an elastic deformation region of the hard portion 11. It is said.

  According to the present embodiment, the rearward surface 341 in the vicinity of the proximal end of the front link element 34 and the frontward surface 342 in the vicinity of the distal end, the downward surface 371 in the vicinity of the proximal end of the back support member 37, and the forward direction of the connection portion 382 of the seat support 38. A concave portion 112 is provided on the surface 383, and a part of the concave portion 112 on the inner side is defined as the facing surface 113, and the front link element 34, the back support member 37, and the connecting portion 38 of the seat receiver 38 are deformed to be predetermined. When the elastic deformation limit of the hard portion 11 is approached, the opposing surfaces 113 come close to each other and the elastic deformation characteristics of the hard portion 11 change greatly, so that the deformation of the hard portion 11 exceeding the elastic deformation limit is suppressed. Therefore, although the support base 31, the front link element 34, the seat support 38 and the back support member 37 are all formed integrally, the support base 31 and the It is possible to realize the operation in accordance to the four-bar linkage by the linking element 34 and the receiving seat 38 and the back support member 37. For this purpose, the lower end portions of the front link element 34 and the back support member 37 are pivotally attached to the support base 31, the upper end portion of the front link element 34 is pivotally attached to the seat receiver 38, and the rear end portion of the seat receiver 38 is back-mounted. The number of parts can be reduced as compared with the conventional one that is pivotally attached to the support member 37. In addition, since the front link element 34 and the back support member 37 do not tilt backward more than a certain amount, a special stopper for restricting the backward rotation of the front link element 34 and the back support member 37 is also unnecessary. .

  In addition, since the elastomer 12 is disposed in the recessed portion 112, the elastic deformation of the hard portion 11 can be adjusted by attaching and detaching or replacing the elastomer 12.

  In addition, the hard portion 11 includes a thin portion 91 and a thick portion 92 that is provided on both sides of the thin portion 91 and has a thickness dimension larger than that of the thin portion 91. Since the recessed portion 112 is formed between 92, such a recessed portion 112 can be arranged without difficulty.

  The present invention is not limited to the embodiment described above.

  For example, although the shape of the recessed portion has been described with respect to the case where the elastomer is filled in a part of the recessed portion of the first to fifth embodiments described above, the present invention includes a case where the recessed portion is not filled with the elastomer. In this case, when the hard portion is deformed to a predetermined elastic deformation limit, the opposing surfaces may be in direct contact with each other to suppress deformation of the hard portion beyond the elastic deformation limit.

  In addition, regardless of whether or not the elastomer is filled, various shapes of the recessed portion are conceivable. In the embodiment, the back side of the recessed portions 112, 132 is expanded to both sides with respect to the opening end side, and the opening width on the back side is set larger than the opening width on the opening end side, that is, Explained what has a T-shape in side view, but the inner side opening width was set larger than the opening end side opening width by bending the inner side of the recessed portion 112 to one side with respect to the opening end side That is, an L-shaped side view as shown in FIG. 12 or an opening on the back side compared to the opening width on the opening end side by bulging the back side of the recessed portion 112 with respect to the opening end side. One having a large width, that is, one having a side keyhole shape as shown in FIG. Further, the recessed portion does not necessarily need to have a larger opening width on the back side than the opening width on the opening end side, and may be, for example, as shown in FIG. 14, FIG. 15, or FIG. In each example, corresponding portions such as the facing surface 113, the thick portion 92, and the thin portion 91 are denoted by the same reference numerals as those in the above-described embodiment, and detailed description thereof is omitted.

  Further, in the embodiment described above, the case where no elastomer is disposed in the recessed portion and the case where the elastomer is filled in a part of the recessed portion has been described, but the elastomer may be disposed in the entire recessed portion. Of course. As an example, as shown in FIG. 17, the outer surface 111 of the hard portion 11 and the outer surface 121 of the elastomer are configured to be flush with each other. Since the elastomer 12 having the same shape as the shape of the recessed portion 112 is provided, an appearance that the structural material is integrated by the hard portion 11 and the elastomer 12 that is the soft portion is obtained. Therefore, the appearance as furniture can be improved. Further, in such a case, when the hard part 11 is deformed to a predetermined elastic deformation limit, the opposing surfaces 113 come into contact with each other via the elastomer 12 to suppress elastic deformation of the hard part 11 beyond a certain level. become. Even when the elastomer is disposed on a part of the recessed portion, the elastomer is disposed only on the opening end side of the recessed portion in addition to the elastomer disposed on the back side of the recessed portion as shown in the embodiment. The thing etc. which were done may be sufficient. That is, when the elastomer is disposed on a part of the recessed portion, when the hard portion is deformed to a predetermined elastic deformation limit, the opposing surfaces directly contact each other and indirectly contact via the elastomer There is.

  In the embodiment described above, the ratio of the thickness dimension between the thick part and the thin part may be set as appropriate according to the required elastic deformation characteristics.

  Further, the thick portion is not limited to a portion having a thickness dimension larger than that of the thin portion, and includes a rib for suppressing elastic deformation even when the thickness portion is the same or smaller than the thin portion. It may be a thing. As a specific example, as shown in FIG. 18 and FIG. 19, a pair of plate-like hard portions 11 that are elastically deformed under a load is provided, and a pair of the hard portions 11 that are elastically deformed is open at the tip side. Examples include a pair of opposing walls 113b provided with protruding opposing surfaces 113. The surface of the facing wall 113b on the side where the facing surface 113 is not formed is connected to a rib 118 formed integrally with the hard portion 11, and deformation other than the direction in which the front end side of the facing surface 113 approaches is restricted. doing. In addition, the shape of the opposing wall 113b which forms these opposing surfaces 113 may be what is shown in FIG.

  Moreover, what kind of thing may be sufficient also about the shape of the elastomer distribute | arranged in a recessed part. As a specific example, as shown in FIG. 21, the shape of the elastomer 12 substantially matches the shape of the recessed portion 112, in other words, the elastomer 12 is disposed on the entire recessed portion 112, or the shape shown in FIG. As shown in FIG. 23, the elastomer 12 is disposed over the entire opening width on the opening end side of the recessed portion 112 and a gap is provided between the opposing surface 113 and the elastomer 12 on the back side. Alternatively, a gap may be provided between the facing surface 113 and the elastomer 12 over the entire depth dimension of the recessed portion 112.

  Furthermore, in the above-described embodiment, the recessed portion is provided on the surface that receives the compressive stress. However, the recessed portion may be provided on the surface that receives the tensile stress due to elastic deformation of the hard portion. More specifically, in the above-described embodiment, the structural material includes a hard portion that is elastically deformed when a load is applied, and is accompanied by the elastic deformation inside as viewed from the bending direction of the hard portion. The structural material is provided with a hard part that elastically deforms when a load is applied, and the outer side is seen from the bending direction of the hard part. A pair of opposing surfaces may be formed which approach each other with the elastic deformation. Here, “inner side as viewed from the bending direction” means a side on which internal stress in the compression direction increases as a load is applied and bending deformation proceeds regardless of the shape. In other words, for example, when an arc-shaped structural material is bent and deformed in a direction in which the radius of curvature becomes smaller, the center of curvature is the inside. On the other hand, when the arc-shaped structural material is bent and deformed in the direction in which the radius of curvature increases, the side opposite to the center of curvature is the inside. Further, “outside as viewed from the bending direction” means a side on which an internal stress in the tensile direction increases as a load is applied and bending deformation proceeds regardless of the shape. In other words, for example, when an arc-shaped structural material is bent and deformed in a direction in which the radius of curvature decreases, the side opposite to the center of curvature is the outside. On the other hand, when the arc-shaped structural material is bent and deformed in a direction in which the radius of curvature increases, the center of curvature is the outside. As a specific example, as shown in FIG. 24 and FIG. 25, a concave portion 112 that is indented into a S-shape or the like in a side view is formed on the side subjected to tensile stress, that is, on the outside as viewed from the bending direction, When the hard portion 11 is deformed to a predetermined elastic deformation limit, the distal end sides of the opposing surfaces 113 forming a pair formed in the recessed portion 112 are close to each other so that the elastic deformation characteristics of the structural material change. Good. In this case, an elastomer may be disposed on a part or all of the recessed portion. 24 and 25 include the rib 118, but may not include the rib as shown in FIG.

  In addition, in the above-described fourth embodiment, the upper end portions of the front link element and the rear link element are pivotally attached to the seat support, and the recessed portions near the front ends of the front link element and the rear link element are omitted. A mode may be adopted in which the member is pivotally attached to the support base, and the recessed portion in the vicinity of the base end is omitted. Furthermore, in the above-described fifth embodiment, the upper end portion of the front link element is pivotally attached to the seat support, and the recessed portion in the vicinity of the front end of the front link element is omitted, or the back support member is pivotally attached to the support base, An aspect in which the recessed portion in the vicinity of the base end is omitted or an aspect in which the rear end portion of the seat receiver is pivotally attached to the back support member and the recessed portion in the connecting portion is omitted may be employed.

  And in 1st-5th embodiment mentioned above, although the opposing surface is provided in the elastic support body which comprises a tilting mechanism, and the back support member which functions as the said elastic support body, the other member which comprises a support mechanism Of course, it is also possible to provide an opposing surface on the elastically deformable member after the structure is elastically deformable.

  In addition, various modifications may be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Chair 11, 13 ... Hard part 112, 132 ... Recessed part 113, 133 ... Opposite surface 12, 14 ... Elastomer 2 ... Leg 3 ... Support mechanism 31 ... Support base 33 ... Curved support 34 ... Front link element 35 ... Rear link element 37 ... back support member (elastic support)
38 ... seat holder 4 ... seat 41 ... seat frame (seat holder)
6 ... Tilt mechanism 61 ... Elastic support 91, 93 ... Thin part 92, 94 ... Thick part

Claims (7)

A chair having at least one of a seat and a backrest supported on a leg via a tilting mechanism;
The tilt mechanism includes a hard part that elastically deforms when a load is applied to at least one of the seat and the backrest, and a pair of opposing surfaces that are provided on the hard part and approach each other with the elastic deformation. When the hard part is deformed and approaches the predetermined elastic deformation limit, the opposing surfaces come close to each other and the elastic deformation characteristics of the hard part change, and the hard part is deformed beyond the elastic deformation limit. A chair characterized by deterrence. The tilt mechanism includes an elastic support provided between a support base supported by a leg and a seat, and the degree of curvature changes according to a load acting on the seat in the elastic support. The chair according to claim 1, wherein the facing surface is provided at a site. The tilting mechanism includes an elastic support provided between a support base supported by a leg and a backrest, and the degree of curvature depends on a load acting on the backrest of the elastic support. The chair according to claim 1, wherein the facing surface is provided at a site that changes. The tilting mechanism includes an elastic support provided between a seat supported by a leg and a backrest, and the degree of curvature changes according to a load acting on the backrest of the elastic support. The chair according to claim 1, wherein the facing surface is provided at a site to be operated. The chair according to claim 1, 2, 3, or 4, wherein the hard portion includes a recessed portion that is opened outward, and a part or all of the inside of the recessed portion that faces each other is the facing surface. . The chair according to claim 5, wherein the hard portion is an elastomer entirely or partially disposed in the recessed portion. The hard part includes a thin part and thick parts having a thickness dimension larger than that of the thin part provided on both sides of the thin part, and the recessed part is formed between the thick parts. The chair according to claim 5 or 6.

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