chair

Abstract

To provide a chair capable of smoothly converting an operation force for positioning of a back plate into a force of moving the back plate.SOLUTION: A chair includes a seat receiving member 20, a back plate 40 in which at least some positions including an extension part 30 in the front and rear direction can be adjusted relatively to the seat receiving member 20, a positioning mechanism 70, and a support member 60 supporting the position adjustment mechanism 70. The position mechanism 70 can adjust, fix, and fixation-release some positions including the extension part 30 of the back plate 40 in the front and rear direction.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a chair. [Background technology]

[0002] BACKGROUND ART Chairs that are adjustable in seat position in the front-to-rear direction have been known for use in offices and the like (for example, Patent Documents 1 and 2).

[0003] Patent Document 1 discloses an operating unit supported on a seat. The operating unit is movable in a direction intersecting the direction of seat movement. The seat occupant operates the operating unit to release the engagement between the operating unit and the engaging teeth, thereby adjusting the position of the seat. Patent Document 2 discloses a lever member that is supported around an axis in the front-to-rear direction of the seat. The lever member is biased in the rotation direction. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4060621 [Patent Document 2] Patent No. 4153740 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the chair described in Patent Document 1, the direction in which the seat position is adjusted is different from the direction in which the operating unit moves. In the chair described in Patent Document 2, the direction in which the lever member rotates is different from the direction in which the seat moves. For this reason, Patent Documents 1 and 2 have a problem in that it is difficult for the seated occupant to apply force to the operating unit when operating it.

[0006] The present invention has been made in consideration of the above problems, and aims to provide a chair in which the operating force for adjusting the position of the seat can be smoothly converted into a force for moving the seat. [Means for solving the problem]

[0007] A chair according to one aspect of the present invention comprises a seat support member, a seat plate located above the seat support member and having an extension portion protruding toward one end in the front-to-rear direction, wherein the position of at least a portion of the seat plate in the front-to-rear direction, including the extension portion, is adjustable relative to the seat support member, a position adjustment mechanism that is capable of adjusting the position of at least a portion of the seat plate in the front-to-rear direction, including the extension portion, fixing the position, and releasing the fixation of the position, and a support member that supports the position adjustment mechanism, wherein the position adjustment mechanism comprises an operating member main body that is pressed in the front-to-rear direction, a main body receiving portion that supports the operating member main body while allowing the operating member main body to be displaced in the front-to-rear direction, and a position fixing member that fixes the position of the main body receiving portion in the front-to-rear direction, wherein when a pressing force is applied to the operating member main body and the operating member main body moves, the position fixing member releases the fixation of the position of the operating member main body, and the position adjustment mechanism adjusts the position of at least a portion of the seat plate in the front-to-rear direction, including the extension portion.

[0008] According to one aspect of the present invention, the seat occupant can adjust the position of at least a portion of the seat panel, including the extension, in the front-to-rear direction simply by gripping the operating member body and the body receiving portion and pressing the operating member body. That is, the seat occupant can move the operating member body and the body receiving portion in one direction in the front-to-rear direction while applying the gripping force of the seat occupant gripping the operating member body and the body receiving portion to the operating member body and the body receiving portion. In other words, the operating force of the seat occupant for adjusting the position of the seat panel, i.e., the gripping force of the seat occupant on the operating member body and the body receiving portion, can be smoothly converted into a force that moves the seat panel in the front-to-rear direction.

[0009] Furthermore, the operating member body, which is pressed in the front-rear direction, and the body receiving portion are separate members, which allows the position of the operating member body to be changed stably and increases the strength of the body receiving portion supported by the seat plate.

[0010] A chair according to one aspect of the present invention includes a movable body that moves at least a portion of the seat plate, including the extension portion, in the forward / backward direction, the movable body being connected to the position adjustment mechanism, and one of the movable body and the position adjustment mechanism may support a spring portion that generates a restoring force that counteracts the pressing force applied to the operating member main body.

[0011] According to the chair of one aspect of the present invention, when the pressing force on the operating member body is released, the position of the operating member body can be returned to its original position by the action of the restoring force of the biasing portion.

[0012] In a chair according to one aspect of the present invention, the main body receiving portion may have an internal extending portion that extends into the interior of the support member, and the support member may have a guide portion that guides the internal extending portion slidably in the forward and backward directions.

[0013] According to the chair of one aspect of the present invention, the support member has a guide portion that guides the internal extension portion of the main body receiving portion, thereby stabilizing the sliding movement of the main body receiving portion relative to the support member.

[0014] In a chair according to one aspect of the present invention, the support member is provided on the seat plate, and when a pressing force is applied to the operating member main body causing the operating member main body to move, the position fixing member releases the fixing of the position of the operating member main body, and the position adjustment mechanism may adjust the position of the extension portion of the seat plate in the fore-and-aft direction.

[0015] According to one aspect of the chair of the present invention, the operating force for adjusting the position of the extension portion, i.e., the gripping force on the operating member main body and the main body receiving portion, can be smoothly converted into a force for moving the seat plate in the forward and backward directions.

[0016] In a chair according to one aspect of the present invention, the support member is provided on the seat support member, and when a pressing force is applied to the operating member main body causing the operating member main body to move, the position fixing member releases the fixing of the position of the operating member main body, and the position adjustment mechanism may adjust the overall position of the seat plate including the extension portion in the fore-and-aft direction.

[0017] According to one aspect of the chair of the present invention, the operating force for adjusting the position of the entire seat, i.e., the gripping force on the pressing operation member, can be smoothly converted into a force for moving the seat in the forward and backward directions. [Effects of the Invention]

[0018] According to the seat and chair of the present invention, the operating force for adjusting the position of the seat plate can be smoothly converted into a force for moving the seat plate. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a perspective view of a chair according to a first embodiment of the present invention, seen obliquely from the front. [Figure 2] FIG. 1 is a perspective view showing the main parts of the seat that constitutes the chair according to the first embodiment of the present invention, showing the seat receiving member, the extension part, the seat plate, and the deformation inducing part. [Figure 3] FIG. 1 is a perspective view showing the main part of a seat constituting a chair according to a first embodiment of the present invention, showing a seat plate and a deformation inducing part. [Figure 4] FIG. 1 is a diagram showing the main parts of a seat that constitutes a chair according to a first embodiment of the present invention, and is an exploded perspective view showing a deformation inducing portion, a support member, and a position adjustment mechanism. [Figure 5] FIG. 1 is a diagram showing the main parts of a seat that constitutes a chair according to a first embodiment of the present invention, and is a cross-sectional view showing the structures of a deformation inducing portion, a support member, and a position adjustment mechanism. [Figure 6] FIG. 1 is a diagram showing the main parts of a seat that constitutes a chair according to a first embodiment of the present invention, and is a cross-sectional view showing the structures of a deformation inducing portion, a support member, and a position adjustment mechanism. [Figure 7]FIG. 2 is a cross-sectional view showing the main part of the seat constituting the chair according to the first embodiment of the present invention, illustrating the operation of the position adjustment mechanism. [Figure 8] FIG. 2 is a cross-sectional view showing the main part of the seat constituting the chair according to the first embodiment of the present invention, illustrating the operation of the position adjustment mechanism. [Figure 9] FIG. 10 is a diagram showing the main parts of a seat constituting a chair according to a second embodiment of the present invention, and is a schematic diagram showing the relationship between the seat plate, seat receiving member, and position adjustment mechanism. DETAILED DESCRIPTION OF THE INVENTION

[0020] A chair according to an embodiment of the present invention will be described with reference to the drawings. In the following description, components having the same or similar functions are denoted by the same reference numerals. Duplicate descriptions of those components may be omitted. The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between parts, etc., may not necessarily be the same as the actual ones.

[0021] In the following explanation, for the sake of convenience, the direction in which an occupant seated in a normal posture on seat 17 faces forward will be referred to as "forward," and the opposite direction will be referred to as "rear." Furthermore, the terms "up, down," and "left, and right" in the following explanation refer to directions that correspond to the direction centered on the occupant when seated in a normal posture on seat 17. The drawings also show an arrow FR pointing forward, an arrow BR pointing backward, an arrow UP pointing upward, an arrow DW pointing downward, an arrow RH pointing rightward, and an arrow LH pointing leftward.

[0022] The upward direction UP and the downward direction DW correspond to the up-down direction (the direction of gravity). The forward direction FR and the backward direction BR each correspond to a first direction that intersects with the up-down direction. The forward direction FR and the backward direction BR each may be a horizontal direction or an inclined direction inclined with respect to the horizontal direction. The forward direction FR and the backward direction BR may also be referred to as the fore-and-aft directions FR and BR. The upward direction UP and the downward direction DW may also be referred to as the up-and-down directions UP and DW.

[0023] The right direction RH and the left direction LH each correspond to a second direction that intersects with the up-down directions UP and DW and the first direction. That is, the right direction RH and the left direction LH are directions that intersect with the up-down directions UP and DW and the front-rear directions FR and BR. The right direction RH or the left direction LH may simply be referred to as a "side view." The downward direction DW may simply be referred to as a "plan view." The right direction RH and the left direction LH may also be referred to as a left-right direction.

[0024] First Embodiment <Overall chair configuration> As shown in Figure 1, the chair 100 according to the first embodiment comprises legs 10 placed on the floor F, a box-shaped base 15 placed on top of the legs 10, a seat 17 attached to the top of the base 15, a backrest 2 attached to the rear of the base 15 to support the back of the occupant, and armrests 19 extending from both sides of the lower side of the seat 17 to the upper side of the seat 17 on which the occupant's elbows and arms can be rested.

[0025] The leg section 10 has a multi-leg 11 with casters 11a, and a base 12 that stands up from the center of the multi-leg 11 and has a built-in gas spring (not shown) that serves as a lifting mechanism. The base 12 has an outer tube 13 and an inner tube 14. The outer tube 13 is fitted and supported on the multi-leg 11 so as not to rotate. The lower part of the inner tube 14 is supported on the outer tube 13 so as to be rotatable in the horizontal direction. The upper part of the inner tube 14 is fixed to a support base 15. The support base 15 has a built-in lift adjustment mechanism for the base 12 and a reclining mechanism for the backrest 2.

[0026] The above-mentioned legs 10, multi-pronged legs 11, casters 11a, pedestals 12, outer cylinder 13, inner cylinder 14, and support base 15 constitute a support structure that supports seat 17.

[0027] <Seat configuration> As shown in FIG. 1, the seat 17 elastically supports the buttocks and thighs of a seated person. 1 to 4, the seat 17 includes an upholstery material 17A, a seat receiving member 20, a seat plate 40, a deformation inducing portion 50, a support member 60, and a position adjustment mechanism 70. The seat plate 40 includes an extension portion 30. It should be noted that the upholstery material 17A is omitted in Fig. 2. Of the components that make up the seat 17, Fig. 2 shows only the seat receiving member 20, the extension portion 30, the seat plate 40, and the deformation inducing portion 50.

[0028] <Tension material> As shown in Fig. 1, the upholstery material 17A covers the upper surface of the seat 17. In other words, the upholstery material 17A covers the upper surface 40T of the seat plate 40 and the upper surface 30T and front surface 30F of the extension portion 30. The upholstery material 17A is made of cloth such as mesh. Elastic members such as cushions may be placed between the upholstery material 17A and the seat plate 40 and between the upholstery material 17A and the extension portion 30.

[0029] <Seat support member> 2, the seat receiving member 20 is fixed to the underside 40L of the seat plate 40. As a fixing structure for fixing the seat receiving member 20 to the seat plate 40, for example, a known fixing structure using screws is adopted. However, the fixing structure is not limited to screw fixing. There are no particular limitations on the material from which the seat receiving member 20 is made, as long as the seat receiving member 20 is made of a strength member that is strong enough to form the seat 17. For example, the seat receiving member 20 can be made of a material such as metal or resin. The seat receiving member 20 has a first edge 20FE located at one end 20T1 in the forward direction FR, and a second edge 20SE located at one end 20T2 in the leftward direction LH.

[0030] <Extension part> The extension portion 30 constitutes a part of the seat panel 40. The extension portion 30 protrudes toward one end of the seat panel 40 in the front-rear direction FR, BR.

[0031] The extension portion 30 is movable in the front-rear directions FR and BR so as to move away from or towards the seat receiving member 20. In other words, the extension portion 30 is movable in the front direction FR so as to move away from the seat receiving member 20. The extension portion 30 is also movable in the rear direction BR so as to move towards the seat receiving member 20. The extension portion 30 is elastically deformable. The extension portion 30 has a bending portion 31, a fixed portion 32, and a movable portion 33.

[0032] In the up-down directions UP and DW, the thickness of the extension portion 30 is thinner than the thickness of the seat plate 40. In addition, the extension portion 30 is a separate member from the seat plate 40. It is preferable that the material constituting the extension portion 30 is more flexible than the material constituting the seat plate 40. The bent portion 31 is formed in a U-shape when viewed in the right-hand direction RH. The fixed portion 32 is a portion that is fixed to the seat panel 40. The movable portion 33 is located on the opposite side to the position where the fixed portion 32 is fixed. In other words, the fixed portion 32 is located on one end side of the extending portion 30. The movable portion 33 is located on the other end side of the extending portion 30. In the up-down directions UP and DW, the movable portion 33 is located below the fixed portion 32. In other words, in the downward direction DW, the movable portion 33 is located at a position away from the fixed portion 32.

[0033] The bent portion 31 is formed in a U-shape when viewed in the right direction RH. The bent portion 31 is located between the fixed portion 32 and the movable portion 33. The extending portion 30 extends so as to overhang the first edge portion 20FE of the seat receiving member 20 in the forward direction FR.

[0034] The extension portion 30 has an opening 30K that penetrates the extension portion 30 in a direction perpendicular to the extension portion 30. Furthermore, the extension portion 30 has a plurality of strip portions 30B. Each of the plurality of strip portions 30B extends along the forward direction FR. The plurality of strip portions 30B are aligned in the rightward direction RH and the leftward direction LH. An opening 30K that opens in the up-down directions UP and DW is formed between two adjacent strip portions 30B among the plurality of strip portions 30B.

[0035] The movable portion 33 has an extending end surface 33E and an intermediate portion 33M. The extending end surface 33E is located at one end 33T of the movable portion 33 in the forward direction FR. The intermediate portion 33M is located between the extending end surface 33E and the bent portion 31. The intermediate portion 33M is a surface located on the inside of the extending portion 30 that is deformed into a U-shape. In this embodiment, the deformation inducing portion 50 is connected to the intermediate portion 33M. As a modified example of the deformation inducing portion 50, the deformation inducing portion 50 may be connected to the extending end surface 33E of the movable portion 33.

[0036] The extension portion 30 is made of an elastically bendable material. As long as the extension portion 30 is elastically bendable, the material from which the extension portion 30 is made is not particularly limited. For example, the extension portion 30 can be made of a material such as resin.

[0037] <Seat board> The position of at least a portion of the seat panel 40 in the front-rear directions FR and BR is adjustable relative to the seat receiving member 20. In other words, the position of the extension portion 30 that constitutes a part of the seat panel 40 is adjustable relative to the seat receiving member 20 in the front-rear directions FR and BR. In this embodiment, the position of the extension portion 30 is adjustable relative to the seat receiving member 20, but the entire seat plate 40 may be adjustable relative to the seat receiving member 20 in the front-rear directions FR and BR.

[0038] The seat panel 40 is connected to the fixing portion 32 of the extension portion 30. The seat panel 40 is located above the seat receiving member 20 and is supported by the seat receiving member 20. The seat panel 40 has a first seat panel portion 17F extending from the first edge portion 20FE in the forward direction FR, and a second seat panel portion 17S extending from the second edge portion 20SE in the right direction RH and the left direction LH. In other words, the seat panel 40 has, on the plate underside 40L, a right region 41 (right edge) in the right direction RH and a left region 42 (left edge) in the left direction LH. In other words, the seat panel 40 has a right edge and a left edge in the left-right direction.

[0039] The first seat panel portion 17F forms part of the underside 40L of the seat panel 40. The second seat panel portion 17S forms part of the underside 40L of the seat panel 40. There is no boundary between the first seat panel portion 17F and the second seat panel portion 17S. On the underside 40L, the first seat panel portion 17F and the second seat panel portion 17S are continuous with each other.

[0040] In other words, on the board underside 40L, the first seat panel portion 17F may be referred to as a first seat panel region extending from the first edge portion 20FE toward the forward direction FR. Similarly, on the board underside 40L, the second seat panel portion 17S may be referred to as a second seat panel region extending from the second edge portion 20SE toward the right direction RH and the left direction LH. In other words, the second seat panel portion 17S has a right seat panel portion 17SR (right seat panel region) extending from the seat receiving member 20 toward the right direction RH, and a left seat panel portion 17SL (left seat panel region) extending from the seat receiving member 20 toward the left direction LH. In this configuration, the seat receiving member 20 is located between the right seat panel portion 17SR and the left seat panel portion 17SL.

[0041] The material from which the seat plate 40 is made is not particularly limited as long as the seat plate 40 has sufficient strength to constitute the seat 17. For example, the seat plate 40 can be made of a material such as metal or resin. In addition, the extension portion 30 and the seat plate 40 may be integrated at the fixing portion 32.

[0042] <Deformation-inducing part> The deformation inducing portion 50 is located below the first seat panel portion 17F. The deformation inducing portion 50 is connected to the movable portion 33 and the position adjustment mechanism 70. The deformation inducing portion 50 is movable in the forward direction FR in accordance with movement of the position adjustment mechanism 70 in the forward direction FR. The deformation inducing portion 50 has a structure that deforms the extending portion 30 so that the bending portion 31 moves in the forward direction FR. Similarly, the deformation inducing portion 50 is movable in the rearward direction BR in accordance with movement of the position adjustment mechanism 70 in the rearward direction BR. The deformation inducing portion 50 has a structure that deforms the extending portion 30 so that the bent portion 31 moves in the rearward direction BR.

[0043] 3 and 4, the deformation inducing unit 50 includes a movable body 51. As will be described later, two support members 60 (60R, 60L) maintain the movable state of the movable body 51 in the front-rear directions FR and BR. For this reason, the two support members 60 (60R, 60L) can also be referred to as parts of the deformation inducing unit 50.

[0044] In this embodiment, the deformation inducing portion 50 is supported by the seat plate 40. Specifically, the deformation inducing portion 50 is fixed to the lower surface 40L of the seat plate 40.

[0045] The seat receiving member 20 is disposed between the two support members 60 (60R, 60L) on the underside 40L of the seat plate 40. This prevents the deformation inducing portion 50 from interfering with the seat receiving member 20 in the structure in which the seat plate 40 and the seat receiving member 20 are connected and fixed. As a modified example of the deformation inducing portion 50, the deformation inducing portion 50 may be supported by the seat receiving member 20.

[0046] <Movable body> The movable body 51 is connected to the position adjustment mechanism 70. The movable body 51 moves at least a portion of the seat panel 40, including the extension portion 30, in the front-rear directions FR and BR in response to the operation of the position adjustment mechanism 70. In other words, the movable body 51 is a member that moves only the extension portion 30 in the front-rear directions FR and BR, or a member that moves the entire seat panel 40, including the extension portion 30, in the front-rear directions FR and BR. In this embodiment, the movable body 51 moves only the extension portion 30.

[0047] The movable body 51 is composed of a rod portion 52 and two rod support portions 55R and 55L. In the structure of the movable body 51, the rod portion 52 and the two rod support portions 55R and 55L may be integrated. In the structure of the movable body 51, the rod portion 52 and the two rod support portions 55R and 55L may be composed of separate members that can be separated from each other. Each of the two rod support portions 55R and 55L has a recess 75R that accommodates a spring 75, which will be described later (see FIG. 5). In the following description, the two rod support portions 55R and 55L may be simply referred to as rod support portion 55.

[0048] The rod portion 52 is a member that extends in the rightward direction RH and the leftward direction LH. 2, the rod portion 52 is connected to and fixed to the movable portion 33 of the extension portion 30. As a fixing structure for fixing the rod portion 52 to the movable portion 33, for example, a known fixing structure using a screw is adopted. However, the fixing structure is not limited to screw fixing.

[0049] The two rod support portions 55R, 55L correspond to the right rod support portion 55R (first rod support portion) and the left rod support portion 55L (second rod support portion). The right rod support portion 55R is provided at the right end of the rod portion 52 in the right direction RH. The left rod support portion 55L is provided at the left end of the rod portion 52 in the left direction LH.

[0050] 4, the position of the rod portion 52 in the up-down directions UP and DW is different from the positions of the two rod support portions 55R and 55L. Specifically, in the downward direction DW, the position of the rod portion 52 is located lower than the positions of the two rod support portions 55R and 55L.

[0051] In other words, rod portion 52 is provided so as to protrude in the downward direction DW from two rod support portions 55R, 55L. The distance in the downward direction DW between rod portion 52 and two rod support portions 55R, 55L, i.e., the distance between the center of rod portion 52 and the centers of rod support portions 55R, 55L, is determined appropriately taking into consideration the curvature of bent portion 31 in extension portion 30, the thickness of seat 17, and the design of chair 100.

[0052] The right rod support portion 55R and the left rod support portion 55L each have an attachment protrusion 56 that is attached to the housing 71 of the position adjustment mechanism 70. The attachment protrusion 56 of the right rod support portion 55R protrudes from the right rod support portion 55R in the right direction RH. The attachment protrusion 56 of the left rod support portion 55L protrudes from the left rod support portion 55L in the left direction LH.

[0053] <Supporting member> 3, each of the two support members 60 (60R, 60L) is provided on the seat plate 40 and fixed to the underside 40L of the seat plate 40. The support members 60 are rails that support the position adjustment mechanism 70. The support members 60 are members that slide the position adjustment mechanism 70 and fix the position of the position adjustment mechanism 70. In the following description, the two support members 60 (60R, 60L) may be simply referred to as the support members 60.

[0054] The two support members 60 (60R, 60L) correspond to a right support member 60R (first support member) and a left support member 60L (second support member). On the plate underside 40L, the right support member 60R is fixed to a right region 41 in the right direction RH, and the left support member 60L is fixed to a left region 42 in the left direction LH. The two support members 60 may be formed integrally with the plate underside 40L of the seat panel 40 or with the right region 41 (right seat panel portion 17SR) and left region 42 (left seat panel portion 17SL) of the seat panel 40 in the left-right direction.

[0055] Each of the right support member 60R and the left support member 60L has an elongated hole 61 extending in the front-rear directions FR and BR, and a plurality of positioning grooves 62 formed inside the elongated hole 61. The plurality of positioning grooves 62 are formed at equal intervals in the front-rear directions FR and BR. Each of the right support member 60R and the left support member 60L has an elongated hole 61 that guides an internal extending portion 74C (described later) so that the internal extending portion 74C can slide in the front-rear directions FR and BR. The elongated hole 61 is an example of a "guide portion" in the present invention. Instead of the elongated hole 61, a rail, which is an example of a guide portion, may be provided on the support member 60.

[0056] As will be described later, the multiple positioning grooves 62 are grooves that engage with protrusions 72P of an engaging member 72 of a position adjustment mechanism 70, which will be described later. The distance between adjacent positioning grooves 62 is determined taking into consideration the range of position adjustment of the bending portion 31 in the front-rear directions FR and BR.

[0057] The right rod support portion 55R is inserted in the right direction RH into the elongated hole 61 of the right support member 60R, and the left rod support portion 55L is inserted in the left direction LH into the elongated hole 61 of the left support member 60L.

[0058] <Position adjustment mechanism> The seat 17 is provided with two position adjustment mechanisms 70 (70R, 70L). The two position adjustment mechanisms 70 (70R, 70L) correspond to a right position adjustment mechanism 70R (first position adjustment mechanism) and a left position adjustment mechanism 70L (second position adjustment mechanism). The two position adjustment mechanisms 70 are supported on the second seat panel portion 17S below the second seat panel portion 17S. The left position adjustment mechanism 70L is supported on the left seat panel portion 17SL. The right position adjustment mechanism 70R is supported on the right seat panel portion 17SR. The two position adjustment mechanisms 70 are connected to the extension portion 30 via the deformation inducing portion 50.

[0059] When the seated person operates the position adjustment mechanism 70, the operating force applied to the position adjustment mechanism 70 is transmitted to the deformation inducing portion 50, and the transmitted force of the deformation inducing portion 50 moves the extension portion 30. In other words, the position adjustment mechanism 70 actuates the extension portion 30. In the following description, the two position adjustment mechanisms 70 (70R, 70L) may be simply referred to as the position adjustment mechanisms 70.

[0060] In other words, the position adjustment mechanism 70 can adjust the position of the extension portion 30 in the front-rear directions FR and BR, fix the position of the extension portion 30, and release the fixed state of the position of the extension portion 30.

[0061] 5 and 6, the position adjustment mechanism 70 includes a housing 71, an engaging member 72, a link member 73, a push button 74A, a button receiving portion 74B, and a spring 75. The housing 71 accommodates the engaging member 72, the link member 73, and the pressing operation member 74.

[0062] The engagement member 72 is a member that fixes the position of the push button 74A in the front-rear directions FR and BR. The engaging member 72 is an example of the "position fixing member" of the present invention. The pressing operation member 74 is composed of a push button 74A and a button receiving portion 74B. The push button 74A is an example of the "operation member main body" in the present invention. The button receiving portion 74B is an example of the "main body receiving portion" in the present invention.

[0063] Spring 75 is an example of the "urging portion" of the present invention. The urging portion is a member that can be elastically deformed and is a portion that generates a restoring force (elastic force). In the example shown in FIG. 5, a coil spring is used as spring 75, but the form of the urging portion is not limited to a coil spring. Any known material or shape may be used for the urging portion as long as it can provide the above-mentioned function of the urging portion. For example, the urging portion may be made of a rubber material, a metal material, or a resin material. A leaf spring may also be used as the urging portion.

[0064] The button receiving portion 74B constitutes a part of the housing 71 and is a portion formed in the housing 71. The button receiving portion 74B has an opening 74E that opens in the forward direction FR and a space 74D. The space 74D constitutes a part of the opening 74E. The button receiving portion 74B is a portion formed in a cylindrical shape extending in the front-rear directions FR and BR shown in FIG. 4. The cylindrical button receiving portion 74B has a space 74D surrounded by a surface including the arcuate surface 71F (see FIG. 5). As shown in FIG. 4, the space 74D has a substantially U-shape when viewed in the rear direction BR. The space 74D has an opening 74E at one end in the forward direction FR, but is closed at one end in the rear direction BR.

[0065] As shown in FIG. 5, inside the space 74D, the button receiving portion 74B has an arcuate surface 71F that follows the outer shape of the push button 74A. The push button 74A has a generally U-shaped configuration when viewed in the rear direction BR in FIG. 4, similar to the shape of the space 74D. The push button 74A is movable along the arcuate surface 71F. The push button 74A may or may not be in contact with the arcuate surface 71F. In other words, the push button 74A is housed inside the space 74D and is movable in the front-rear directions FR and BR within the space 74D.

[0066] Left side LH In space 74D Left edge The surface located at Right direction RH In space 74D Right edge In other words, the space 74D faces the surface located at Left edge Located in Left edge Face and Right edge Located in Right edge The face is Left and right direction LH, RH It blocks space 74D. A portion of the push button 74A protrudes from the space 74D in the forward direction FR through the opening 74E. That is, a portion of the push button 74A is exposed to the outside of the button receiving portion 74B at an end of the button receiving portion 74B in the forward direction FR.

[0067] The button receiving portion 74B includes an inner extending portion 74C that extends into the inside of the support member 60 through the elongated hole 61. The inner extending portion 74C is a portion that is guided by the elongated hole 61 as the pressing operation member 74 moves in the front-rear directions FR and BR.

[0068] The push button 74A is a portion that is pressed in the front-rear directions FR and BR by a seat occupant. The button receiving portion 74B supports the push button 74A, allowing the push button 74A to be displaced in the front-rear directions FR and BR. The pressing operation member 74 is movable in the front-rear directions FR and BR.

[0069] In other words, the push button 74A and the button receiving portion 74B are portions that are gripped by the fingers of the seated person when the seated person operates the pressing operation member 74, and are portions to which the gripping force of the seated person is applied.

[0070] Specifically, when a seated person grips push button 74A and button receiver 74B with their thumb and index finger to operate pressing operation member 74, push button 74A is, for example, the part that comes into contact with the seated person's thumb, and button receiver 74B is the part that comes into contact with the seated person's index finger and middle finger. Conversely, push button 74A may come into contact with the seated person's index finger and middle finger, and in this case, for example, button receiver 74B is the part that comes into contact with the seated person's thumb.

[0071] The parts of the occupant's fingers that come into contact with the push button 74A and the button receiving portion 74B are not necessarily the thumb, index finger, and middle finger. Depending on the grip strength or habits of the occupant using the chair 100, a gripping force may be applied to the push button 74A and the button receiving portion 74B by fingers other than the thumb, index finger, and middle finger. Also, one of the push button 74A and the button receiving portion 74B may be pressed with two fingers, or one of the push button 74A and the button receiving portion 74B may be pressed with the joints of the fingers.

[0072] As long as the position adjustment mechanism 70 can operate stably even if the number of operations of the position adjustment mechanism 70 increases, there are no particular limitations on the materials used to form the housing 71, the engaging member 72, the link member 73, the push button 74A, and the button receiving portion 74B. For example, the components of the position adjustment mechanism 70 can be formed from materials such as metal or resin.

[0073] The spring 75 is supported by the rod support portion 55. The spring 75 is housed inside the support member 60. The spring 75 is Left side LH That is, the spring 75 generates a restoring force that opposes the pressing force applied to the push button 74A. 5, spring 75 is supported by rod support portion 55 that constitutes movable body 51. As a modification, spring 75 may be supported by housing 71. In this modification, a recess 75R that accommodates spring 75 is formed in housing 71.

[0074] (Modification of the biasing portion) In the above example, the spring 75 constituting the biasing portion is a separate member from each of the rod support portion 55 and the engaging member 72. For this reason, the spring 75 can also be referred to as a biasing member. On the other hand, the biasing portion may be a part of a member constituting the position adjustment mechanism 70, or may be a part of the movable body 51. In other words, the biasing portion may be a part formed integrally with a member constituting the position adjustment mechanism 70 or a member constituting the movable body 51.

[0075] Specifically, one of the engaging member 72, the link member 73, the pressing operation member 74, and the rod support portion 55 may have a structure including a biasing portion. As an example, the engaging member 72 and the biasing portion may be integrally formed. In this case, the engaging member 72 has a main body portion having the function of the engaging member and an elastically deforming portion (biasing portion) that is elastically deformable. An example of the elastically deforming portion is a resin spring. In one variation of the engaging member 72, the elastically deforming portion and the main body portion are integrated by using the same resin material to form the engaging member 72.

[0076] In this configuration, the main body portion has a sufficient thickness so that the engaging member 72 has sufficient strength even when the position adjustment mechanism 70 is repeatedly operated. On the other hand, the elastically deforming portion has a thickness thinner than the main body portion so that it can be elastically deformed. The resin spring forming part of the engaging member 72 is disposed, for example, in a compressed state (a contracted state) between the inner wall of the support member 60 and the engaging member 72. As shown in Fig. 5, the inner wall of the support member 60 is, for example, a surface on which a plurality of positioning grooves 62 are formed.

[0077] Note that "integration of the elastically deforming portion and the main body portion" is not limited to integration of the elastically deforming portion and the main body portion by using the same material. The material forming the elastically deforming portion and the material forming the main body portion may be different. In this case, the engaging member 72 is provided with an engaging portion (concave and concave portion) where the elastically deforming portion and the main body portion are fixed by engaging with each other, or a press-fit portion where the elastically deforming portion is press-fitted into the main body portion to fix the elastically deforming portion and the main body portion.

[0078] Furthermore, the link member 73, the pressing operation member 74, and the rod support portion 55 may each include a biasing portion. In this case, the link member 73, the pressing operation member 74, and the rod support portion 55 may have a structure in which the elastic deformation portion and the main body portion are integrated together.

[0079] The connection structure of the left position adjustment mechanism 70L, the left support member 60L, and the left rod support portion 55L will be described with reference to FIGS. 5 and 6 show a cross section of the left position adjustment mechanism 70L. Specifically, FIG. 5 shows the positional relationship between the engagement member 72 and the push button 74A. FIG. 5 also shows a state in which the engagement member 72 is fitted into the positioning groove 62. FIG. 6 shows a cross section of the left position adjustment mechanism 70L that is different from the cross section shown in FIG. 5. FIG. 6 shows a connected state between the engagement member 72, link member 73, and push button 74A.

[0080] Since the structure of the left position adjustment mechanism 70L is the same as the structure of the right position adjustment mechanism 70R, the right position adjustment mechanism 70R may be omitted in the description with reference to Figures 4 to 6. Similarly, since the structure of the left support member 60L is the same as the structure of the right support member 60R, the right support member 60R may be omitted in the description with reference to Figures 4 to 6.

[0081] As shown in Fig. 4, the housing 71 has a connecting protrusion 76 that is connected to the left rod support portion 55L. The connecting protrusion 76 protrudes from the housing 71 in the rightward direction RH. In the structure shown in Fig. 4, the connecting protrusion 76 is shown spaced apart from the left rod support portion 55L, but when the left position adjustment mechanism 70L is attached to the left rod support portion 55L as shown in Figs. 2 and 3, the connecting protrusion 76 passes through the elongated hole 61 of the left support member 60L and is connected to the left rod support portion 55L.

[0082] 5 and 6, in the housing 71 of the left position adjustment mechanism 70L, the engagement member 72 extends in the front-rear direction. Left and right direction The push button 74A is movable in the front-rear direction. The engagement member 72, the link member 73, and the push button 74A are connected to one another. The housing 71 maintains the connected state of the engagement member 72, the link member 73, and the push button 74A.

[0083] The link member 73 and the push button 74A are connected via a first shaft 77 (axial center) extending in the leftward direction LH. When a seated person presses the push button 74A, as long as the pressing force can be transmitted to the link member 73, the push button 74A may be fixed to the link member 73, or the push button 74A may be rotatable around the first shaft 77 relative to the link member 73. In this embodiment, a structure is adopted in which the push button 74A is rotatable around the first shaft 77 relative to the link member 73. In a structure in which the push button 74A is fixed to the link member 73, the link member 73 and the push button 74A may be configured as an integrated member.

[0084] The engaging member 72 and the link member 73 are connected and fixed via a second shaft 78 (axial center) extending in the leftward direction LH. Therefore, when a seat occupant presses the push button 74A, the pressing force can be transmitted to the engaging member 72 via the link member 73. In this embodiment, the engagement member 72 and the link member 73 are separate components. However, the engagement member 72 and the link member 73 may be formed as an integrated member as long as the pressing force of the seated occupant can be transmitted to the engagement member 72.

[0085] The engaging member 72 is Left side LH The left support member 60L has a protrusion 72P that protrudes toward the left support member 60L. The protrusion 72P is capable of selectively engaging with a plurality of positioning grooves 62 formed in the bottom surface 61B of the elongated hole 61 of the left support member 60L. As described above, the position adjustment mechanism 70 has a structure in which the push button 74A, the first shaft 77, the link member 73, the second shaft 78, and the engagement member 72 are connected together. In this structure, when a pressing force is applied to the push button 74A and the push button 74A moves in the rear direction BR, the protrusion 72P provided at the tip of the engagement member 72 Right direction RH Go to.

[0086] On the other hand, when the pressing force on the push button 74A is released, the push button 74A moves in the forward direction FR, and the protrusion 72P provided at the tip of the engagement member 72 Left side LH In other words, the position adjustment mechanism 70 adjusts the amount of movement of the push button 74A in the front-rear directions FR and BR. Left and right direction LH, RH It is possible to convert this into the amount of movement of the protrusion 72P in the

[0087] The left position adjustment mechanism 70L described above is operated by the seat occupant pressing the push button 74A and sliding the left position adjustment mechanism 70L on the left support member 60L. The left position adjustment mechanism 70L is also operated by the right position adjustment mechanism 70R. By simultaneously operating the left position adjustment mechanism 70L and the right position adjustment mechanism 70R, the position of the deformation inducing portion 50 is adjusted and the position of the deformation inducing portion 50 is determined.

[0088] As described above, the deformation inducing unit 50 has a structure in which the rod portion 52 constituting the deformation inducing unit 50 is connected to the movable portion 33 of the extension portion 30. The deformation inducing unit 50 can slide (move) the position adjustment mechanism 70 constituting the deformation inducing unit 50 relative to the support member 60 by operating the position adjustment mechanism 70.

[0089] Moreover, the deformation inducing portion 50 has a structure that elastically deforms the extension portion 30 so that the movable portion 33 approaches the seat receiving member 20 or moves away from the seat receiving member 20 as the deformation inducing portion 50 moves along the front-rear directions FR, BR. Moreover, the deformation inducing portion 50 having the above structure has a structure that slides on the support member 60.

[0090] <How to adjust the position of the extension part> Next, a method for adjusting the position of the extension portion 30 will be specifically described with reference to Figures 5 to 8. Of the components constituting the chair 100 described above, only the seat 17 is shown in Figures 7 and 8, and other components are omitted.

[0091] The method for adjusting the position of the extension portion is carried out in the following steps. Step 1: The push buttons 74A of the left position adjustment mechanism 70L and the right position adjustment mechanism 70R are pressed to release the engagement state of the engagement members 72. Step 2: Sliding of the left position adjustment mechanism 70L and the right position adjustment mechanism 70R into the elongated holes 61 of the left support member 60L and the right support member 60R. Step 3: End of pressing of the push buttons 74A of the left position adjustment mechanism 70L and the right position adjustment mechanism 70R Next, steps 1 to 3 above will be explained in order.

[0092] <Step 1> In the chair 100, a seated person grasps the pressing operation members 74 of the left position adjustment mechanism 70L and the right position adjustment mechanism 70R with their fingers and applies a pressing force between the push button 74A and the button receiver 74B. When the push button 74A is pressed, the pressing force of the seated person is transmitted from the push button 74A to the link member 73, and from the link member 73 to the engaging member 72. When the pressing force of the seated person is greater than the force (restoring force) with which the spring 75 biases the engaging member 72, the push button 74A moves in the rear direction BR, and the protrusion 72P of the engaging member 72 moves away from the positioning groove 62. This causes the engaging member 72 to release the fixed position of the pressing operation member 74.

[0093] On the other hand, when the pressing force of the seated occupant is smaller than the force with which the spring 75 urges the engaging member 72, the push button 74A does not move in the rearward direction BR, and the positioning state by the protrusion 72P of the engaging member 72 is maintained. In other words, the engaging member 72 maintains the fixed state of the position of the pressing operation member 74. In step 2, the state in which the protrusion 72P is separated from the positioning groove 62 will be described.

[0094] <Step 2> When the protrusion 72P is separated from the positioning groove 62, i.e., when the engagement between the protrusion 72P and the positioning groove 62 is released, the pressing operation member 74 is movable in the front-rear directions FR and BR. That is, the left position adjustment mechanism 70L is slidable relative to the elongated hole 61 of the left support member 60L. Similarly, the right position adjustment mechanism 70R is slidable relative to the elongated hole 61 of the right support member 60R.

[0095] In this state, the seated person slides each of the left position adjustment mechanism 70L and the right position adjustment mechanism 70R relative to the long holes 61. This allows the seated person to adjust the position of the left position adjustment mechanism 70L relative to the left support member 60L, and similarly, the position of the left position adjustment mechanism 70L relative to the right support member 60R.

[0096] That is, the seat occupant can adjust the position of the extension portion 30 in the front-rear directions FR and BR using the left position adjustment mechanism 70L and the right position adjustment mechanism 70R. In other words, the position of the deformation inducing portion 50 on the seat 17 in the front-rear directions FR and BR can be adjusted. This makes it possible to adjust the position of the movable portion 33 of the extension portion 30 connected to the deformation inducing portion 50 in the front-rear directions FR and BR. In other words, it is possible to adjust the position of the bent portion 31 of the extension portion 30 in the front-rear directions FR and BR.

[0097] Specifically, when the deformation inducing portion 50 moves from the position shown in Fig. 8 to the position shown in Fig. 7, the deformation inducing portion 50 moves in the forward direction FR so as to approach the bent portion 31. At this time, the movable portion 33 of the extending portion 30 moves away from the seat receiving member 20. 7 to the position shown in Fig. 8, the deformation inducing portion 50 moves in the rear direction BR so as to move away from the bent portion 31. At this time, the movable portion 33 of the extending portion 30 approaches the seat receiving member 20.

[0098] <Step 3> The seat occupant also removes his or her fingers from the push buttons 74A of the left position adjustment mechanism 70L and the right position adjustment mechanism 70R. In this state, the restoring force of the spring 75 acts to move the engaging member 72. Left side LH The engaging member 72 is biased toward the Left side LH When the protrusion 72P reaches a position corresponding to one of the positioning grooves 62 while being biased toward the left support member 60L, the restoring force of the spring 75 causes the engaging member 72 to engage with the positioning groove 62. This determines the position of the left position adjustment mechanism 70L relative to the left support member 60L, and also determines the position of the right position adjustment mechanism 70R relative to the right support member 60R.

[0099] That is, the seated person can determine the position of the deformation inducing portion 50 on the seat 17. This makes it possible to determine the position of the movable portion 33 of the extension portion 30 connected to the deformation inducing portion 50. That is, it becomes possible to determine the position of the bent portion 31 of the extension portion 30.

[0100] <Modification of Steps 2 and 3> In steps 2 and 3 described above, the seated person does not need to keep pressing the push button 74A to move the deformation inducing portion 50. After the engagement between the protrusion 72P and the positioning groove 62 is released, the seated person may release their finger from the push button 74A and bring the protrusion 72P into contact with the bottom surface 61B of the elongated hole 61. In other words, the protrusion 72P of the engaging member 72 may be removed from the positioning groove 62 and slid on the bottom surface 61B of the elongated hole 61. In other words, the position of the bent portion 31 of the extension portion 30 can be adjusted while sliding the protrusion 72P on the bottom surface 61B.

[0101] According to chair 100 equipped with seat 17 described above, since position adjustment mechanism 70 is supported by second seat panel portion 17S below second seat panel portion 17S, position adjustment mechanism 70 can be easily attached to seat panel 40. When a seated person sits on seat panel 40, the seated person can easily touch position adjustment mechanism 70 located below second seat panel portion 17S simply by lowering their fingers from their shoulders to their fingertips in the downward direction DW. This allows the seated person to easily operate position adjustment mechanism 70.

[0102] Furthermore, the width of the seat 17 can be easily adjusted through a simple structure in which the position adjustment mechanism 70 that operates the extension portion 30 is supported on the second seat plate portion 17S below the second seat plate portion 17S, so the structure of the components that make up the chair can be simpler than that of conventional chairs.

[0103] Because the extension portion 30 has the fixing portion 32, the extension portion 30 can be fixed to the first seat panel portion 17F. Because the movable portion 33 of the extension portion 30 is movable by operating the position adjustment mechanism 70, the extension portion 30 can be moved by operating the position adjustment mechanism 70. Because the extension portion 30 has the bending portion 31, the extension portion 30 can be moved by operating the position adjustment mechanism 70 while maintaining the deformed state of the extension portion 30.

[0104] The deformation inducing portion 50 has a structure that deforms the extending portion 30 so that the bent portion 31 moves in the front-rear directions FR and BR in accordance with movement of the position adjustment mechanism 70 in the front-rear directions FR and BR. Therefore, by operating the position adjustment mechanism 70 to move the deformation inducing portion 50 in the front-rear directions FR and BR, the operating force applied from the position adjustment mechanism 70 to the deformation inducing portion 50 is transmitted to the movable portion 33 of the extending portion 30, allowing the movable portion 33 to move smoothly in the front-rear directions FR and BR. Since the bent portion 31 moves in the front-rear directions FR and BR in accordance with movement of the movable portion 33, the position of the bent portion 31 can be adjusted, and the width of the seat 17 in the front-rear directions FR and BR can be easily adjusted.

[0105] Since the deformation inducing portion 50 is movable in the front-rear directions FR and BR, the displacement direction of the extension portion 30 coincides with the displacement direction of the deformation inducing portion 50 in the front-rear directions FR and BR. This allows the seat occupant to intuitively adjust the width of the seat 17 in the front-rear directions FR and BR.

[0106] When the deformation inducing portion 50 moves so as to approach the bent portion 31 in the front-rear directions FR and BR, the deformation inducing portion 50 moves the movable portion 33 away from the seat receiving member 20. Also, when the deformation inducing portion 50 moves so as to move away from the bent portion 31 in the front-rear directions FR and BR, the deformation inducing portion 50 moves the movable portion 33 toward the seat receiving member 20. This makes the displacement direction of the extension portion 30 and the displacement direction of the deformation inducing portion 50 coincide with each other in the front-rear directions FR and BR. This allows the seated occupant to intuitively adjust the width of the seat 17 in the front-rear directions FR and BR.

[0107] Furthermore, by simply holding the push button 74A and the button receiving portion 74B that constitute the pressing operation member 74 and pressing the push button 74A, the occupant can adjust the position of at least a portion of the seat plate 40, including the extension portion 30, in the fore-and-aft directions FR and BR.

[0108] That is, the seated occupant can move the pressing operation member 74 in one direction in the front-to-rear directions FR and BR while applying a gripping force for gripping the pressing operation member 74 to the push button 74A and the button receiving portion 74B. In other words, the operating force for adjusting the position of the seat panel 40, that is, the seated occupant's gripping force on the pressing operation member 74, can be smoothly converted into a force for moving the seat panel 40 in the front-to-rear directions FR and BR.

[0109] Furthermore, the push button 74A, which is pressed in the front-rear directions FR and BR, and the button receiver 74B are separate members in the pressing operation member 74. This allows the position of the push button 74A to be changed stably, and the strength of the button receiver 74B, which is supported by the seat panel 40, can be increased.

[0110] Furthermore, when the pressing force on the push button 74A is released, the restoring force of the spring 75 allows the push button 74A to return to its original position.

[0111] Furthermore, since the support member 60 has the elongated hole 61 that guides the internally extending portion 74C of the button receiving portion 74B, the sliding movement of the pressing operation member 74 relative to the support member 60 can be stabilized.

[0112] In addition, the operating force of the occupant for adjusting the position of the extension portion 30, that is, the gripping force of the occupant on the pressing operation member 74, can be smoothly converted into a force that moves the seat plate 40 in the front-to-rear directions FR and BR.

[0113] In the chair 100 according to the first embodiment described above, the seat plate 40 is configured to adjust the position of only the extension portion 30 in the front-rear directions FR and BR relative to the seat receiving member 20. Furthermore, the position adjustment mechanism 70 is configured to adjust the position of the extension portion 30 in the front-rear directions FR and BR, fix the position of the extension portion 30, and release the fixation of the position of the extension portion 30. The present invention is not limited to the chair 100 according to the first embodiment, and may be capable of adjusting the overall position of the seat panel 40 in the front-rear directions FR and BR as will be described in the second embodiment. An embodiment of a chair in which the overall position of the seat panel 40 can be adjusted will be described below.

[0114] Second Embodiment <Overall chair configuration> As shown in FIG. 9, a chair 200 according to the second embodiment includes a seat receiving member 20, a seat plate 40, a support member 60, a position adjustment mechanism 70, a connecting member 80, and a guide rail 90. 9, the same members as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted or simplified. Also, the description of the same method of operating the position adjustment mechanism 70 as that in the first embodiment will be omitted or simplified.

[0115] The seat plate 40 is located above the seat receiving member 20 and has an extension portion 30 that protrudes toward one end in the front-rear directions FR and BR. The seat plate 40 is configured so that the overall position of the seat plate 40, including the extension portion 30, can be adjusted relative to the seat receiving member 20 in the front-rear directions FR and BR.

[0116] The position adjustment mechanism 70 is capable of adjusting the overall position of the seat plate 40 including the extension portion 30 in the front-to-rear directions FR and BR, fixing the overall position of the seat plate 40, and releasing the fixing of the overall position of the seat plate 40. The pressing operation member 74 of the position adjustment mechanism 70 is connected to the seat plate 40 via a connecting member 80. In other words, the seat plate 40 is configured so that the entire seat plate 40 moves in the front-rear directions FR, BR as the pressing operation member 74 moves in the front-rear directions FR, BR. The support member 60 and the position adjustment mechanism 70 are provided on the seat receiving member 20.

[0117] The connecting member 80 protrudes from the seat receiving member 20 and extends in the upward direction UP. The connecting member 80 is a movable body that moves the entire seat panel 40, including the extension portion 30, in the front-to-rear directions FR and BR. In other words, by operating the position adjustment mechanism 70, the force applied to the position adjustment mechanism 70 is transmitted to the connecting member 80, which functions as a movable body, and moves the entire seat panel 40 in the front-to-rear directions FR and BR.

[0118] The guide rails 90 are disposed between the seat receiving member 20 and the seat plate 40. The guide rails 90 allow the seat plate 40 to move relative to the seat receiving member 20 in the front-rear directions FR and BR.

[0119] Next, adjustment of the overall position of the seat panel 40 in the front-rear directions FR and BR will be described. In chair 200, a seated person grips position adjustment mechanism 70 with their fingers and applies a pressing force between push button 74A and button receiving portion 74B. Here, when the pressing force of the seated occupant is greater than the force (restoring force) with which the spring 75 urges the engaging member 72, the push button 74A moves in the rearward direction BR, and the protrusion 72P of the engaging member 72 moves away from the positioning groove 62. As a result, the engaging member 72 releases the fixed position of the pressing operation member 74. In this state, when the pressing operation member 74 moves in the front-rear direction FR, BR, the position adjustment mechanism 70 adjusts the overall position of the seat panel 40 including the extension portion 30 in the front-rear direction FR, BR.

[0120] The seated occupant removes their fingers from the push button 74A. In this state, the engagement member 72 is biased in the downward direction DW by the action of the restoring force of the spring 75. When the protrusion 72P reaches a position corresponding to one of the positioning grooves 62 while the engagement member 72 is biased in the downward direction DW, the engagement member 72 engages with the positioning groove 62 by the action of the restoring force of the spring 75. This determines the position of the position adjustment mechanism 70 relative to the support member 60. In other words, the overall position of the seat panel 40, including the extension 30, is determined.

[0121] According to the chair 200 described above, it is possible to obtain the same effects as those obtained by the chair 100 according to the first embodiment. Furthermore, the operating force of the occupant to adjust the overall position of the seat plate 40 including the extension portion 30, i.e., the occupant's gripping force on the pressing operation member 74, can be smoothly converted into a force to move the seat plate 40 in the forward and backward directions FR and BR.

[0122] While preferred embodiments of the present invention have been described, it should be understood that these are illustrative of the invention and should not be considered as limiting. Additions, omissions, substitutions, and other modifications can be made without departing from the scope of the invention. Accordingly, the present invention should not be deemed limited by the foregoing description, but rather by the scope of the claims. [Explanation of symbols]

[0123] 10 Leg, 11 Branch leg, 11a Caster, 12 Pillar, 13 Outer tube, 14 Inner tube, 15 Support base, 17 Seat, 17A Upholstery material, 17F First seat plate portion, 17S Second seat plate portion, 17SL Left seat plate portion, 17SR Right seat plate portion, 20 Seat support member, 20FE First edge portion, 20SE Second edge portion, 30 Extension portion, 30 B... Belt-shaped portion, 30F... Front surface, 30K... Opening, 30T... Upper surface, 31... Bending portion, 32... Fixed portion, 33... Movable portion, 33E... Extended end surface, 33M... Middle portion, 40... Seat plate, 40L... Lower surface of plate, 40T... Upper surface of plate, 41... Right region, 42... Left region, 50... Deformation-inducing portion, 51... Movable body, 52... Rod portion, 55R, 55L... Rod support portion, 56, protrusion, 60, 60R, 60L, support member, 61, elongated hole (guide portion), 61B, bottom surface, 62, groove, 70, 70L, 70R, position adjustment mechanism, 71, housing, 71F, arc surface, 72, engagement member (position fixing member), 72P, protrusion, 73, link member, 74, pressing operation member, 74A, push button ( Operating member main body, pressing operation member), 74B... Button receiving portion (main body receiving portion, pressing operation member), 74C... Inner extending portion, 75... Spring (biasing portion), 74D... Space, 74E... Opening, 75R... Recess, 76... Connecting protrusion, 77... First shaft, 78... Second shaft, 80... Connecting member (movable body), 90... Guide rail, 100, 200... Chair

Claims

1. A seat receiving member; a seat plate located above the seat receiving member, having an extension portion protruding toward one end in the front-rear direction, and at least a portion of the position including the extension portion in the front-rear direction being adjustable relative to the seat receiving member; a position adjustment mechanism that is capable of adjusting the position of at least a part of the seat plate including the extension portion in the front-rear direction, fixing the position, and releasing the fixation of the position; a support member that supports the position adjustment mechanism and has a plurality of positioning grooves aligned in the front-rear direction; Equipped with The position adjustment mechanism includes: an operating member body that is pressed in the front-rear direction; a body receiving portion that supports the operating member body so as to be rotatable in the front-rear direction while allowing the operating member body to be displaced in the front-rear direction; a position fixing member that can be selectively engaged with the plurality of positioning grooves and that fixes the position of the main body receiving portion in the front-rear direction by engaging with any one of the plurality of positioning grooves; an axis that rotatably supports the position fixing member and rotates the position fixing member in accordance with rotation of the operating member body; a spring that generates a restoring force against a pressing force applied to the operating member body to urge the position fixing member and engage the position fixing member with any of the plurality of positioning grooves; Equipped with When an operator grips the operating member body and the body receiving portion, the pressing force is applied to the operating member body, causing the operating member body to move in the rearward direction of the front-rear direction relative to the body receiving portion, the position fixing member releases the fixing of the position of at least a part of the seat plate, including the extension portion, to make it movable in the front-rear direction, and the position adjustment mechanism adjusts the position of at least a part of the seat plate, including the extension portion, in the front-rear direction by an operating force in the front-rear direction input by the operator while gripping the operating member body following the input of the pressing force. chair.

2. a movable body that moves at least a portion of the seat plate including the extension portion in the front-rear direction; the movable body is connected to the position adjustment mechanism, One of the movable body and the position adjustment mechanism supports a biasing part that generates a restoring force against a pressing force applied to the operating member main body. The chair of claim 1.

3. the main body receiving portion includes an internal extension portion that extends into the support member, The support member has a guide portion that guides the internal extension portion so that the internal extension portion can slide in the front-rear direction.

3. The chair according to claim 1 or claim 2.

4. The support member is provided on the seat plate, When a pressing force is applied to the operating member body and the operating member body moves, the position fixing member releases the fixing of the position of at least a part of the seat plate including the extension portion, and the position adjustment mechanism adjusts the position of the extension portion of the seat plate in the front-rear direction. A chair according to any one of claims 1 to 3.

5. The support member is provided on the seat receiving member, When a pressing force is applied to the operating member body and the operating member body moves, the position fixing member releases the fixing of the position of at least a part of the seat plate including the extension portion, and the position adjustment mechanism adjusts the overall position of the seat plate including the extension portion in the front-rear direction. A chair according to any one of claims 1 to 3.

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