chair

Abstract

To provide a chair including an adjustment lever having a substantially cylindrical outer shape with suppressed complexity and capable of preferably exhibiting an indicator function of indicating a rotation posture.SOLUTION: Provided is a chair including an adjustment lever rotatably supported by a support member. The adjustment lever includes in one end an operation part gripped by a user to apply a rotary operation force. The operation part includes an operation part body having a substantially cylindrical shape opened outward, and a projection part projecting from an inner circumferential surface of the operation part body to a center part of the operation part body.SELECTED DRAWING: Figure 10

Description

[Technical field]

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

[0002] 2. Description of the Related Art There has been known a chair that is rotatably supported on a support member such as a support base and that includes an adjustment lever that can operate an adjustment mechanism (see, for example, Patent Document 1).

[0003] Among conventional adjustment levers, there are ones whose tip portion extends outward in a cantilever manner so as to intersect with the axis of the rotation shaft, but such adjustment levers have problems in that the cantilevered portion can easily catch on clothing, personal belongings, and other objects, and that the cantilevered portion is easily broken when subjected to an external force.

[0004] On the other hand, some conventional adjustment levers have a relatively simple cylindrical tip. However, with such adjustment levers, it is difficult for users to easily grasp the current rotational position at a glance. Users who cannot rely on the appearance of the adjustment lever actually sit or lean against the backrest to roughly grasp the rotational position of the adjustment lever by physical sensation. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2020-116461 A Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide a chair having an adjustment lever that has at least a substantially cylindrical outer shape with reduced complexity, while being able to preferably perform the indicator function of indicating the rotation posture. [Means for solving the problem]

[0007] That is, the present invention has the following configuration.

[0008] The invention described in claim 1 is a chair comprising an adjustment lever rotatably supported on a support member, the adjustment lever having an operation part at one end which is gripped by a user to apply a rotational operation force, the operation part having an operation part main body having a generally cylindrical shape that is open outward, and a mark part provided at an end of the operation part main body and extending toward the center of the operation part main body. The marker portion is a protrusion protruding from the inner circumferential surface of the operation portion body toward the center of the operation portion body, and the operation portion body is configured such that the outer circumferential surface of the tip portion is positioned in a direction gradually approaching the tip, and the outer circumferential surface of the tip portion is formed with a marker recess having a width dimension substantially the same as the thickness dimension of the protrusion at a position corresponding to the protrusion, and a plurality of grooves for preventing finger slippage are provided along the axis at other positions. It's a chair.

[0010] Claim 2 The invention described in claim 2 is characterized in that the protrusion is in the form of a standing wall extending along the longitudinal direction of the adjustment lever. 1 This is the chair described.

[0011] Claim 3 The invention described in claim 1 is characterized in that the protruding portion has an outwardly facing end surface for use as a marker at a position outside an outwardly facing end edge of the operation portion body or at a position substantially coinciding with the end edge. 1 or 2 This is the chair described.

[0012] Claim 4 The invention described in claim 1 is characterized in that the protruding portion has a shape portion that gradually narrows toward the axis. 1、 2 or This is the chair described in 3.

[0014] Claim 5The invention described in claims 1, 2 and 3 is characterized in that the adjustment lever includes the operating portion, an intermediate connecting portion connected to the operating portion with its axis aligned and having an outer diameter that decreases with increasing distance from the operating portion, and a lever base portion connected to the intermediate connecting portion with its axis aligned and having a portion that is pivotally supported by the support member. or This is the chair described in 4.

[0015] Claim 6 The invention described in claim 1 is characterized in that the operating portion, the intermediate connecting portion, and the lever base shaft portion are integrally formed from a synthetic resin. 5 This is the chair described.

[0016] Claim 7 The invention described in claims 1, 2, 3, 4, and 5 is a support base that is attached to the legs and can support the backrest so that it can be tilted backward. or This is the chair described in 6.

[0017] Claim 8 The invention described in claim 1 is characterized in that the support base is provided with a reaction force generating portion that generates a reaction force for the backrest to be tilted backward, and the adjustment lever is a reaction force adjustment lever that engages with the reaction force generating portion. 7 This is the chair described. Effect of the Invention

[0018] As described above, according to the present invention, it is possible to provide a chair having at least an approximately cylindrical outer shape with reduced complexity, and an adjustment lever that can preferably perform the indicator function of indicating the rotation posture. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a perspective view showing an embodiment of the present invention. [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4] FIG. [Diagram 5] FIG. [Figure 6] FIG. [Figure 7] FIG. [Figure 8] FIG. [Figure 9] FIG. [Figure 10] FIG. [Figure 11] FIG. [Figure 12] FIG. 4 is a plan view of an adjustment lever (reaction force adjustment lever) in the embodiment. [Figure 13] Cross-sectional view taken along line AA in FIG. 9(a). [Figure 14] FIG. [Figure 15] FIG. [Figure 16] FIG. [Figure 17] FIG. [Figure 18] FIG. [Figure 19] Cross-sectional view of line BB in Figure 2. [Figure 20] Cross-sectional view taken along line CC in FIG. 2. [Figure 21] Cross-sectional view of line DD in Figure 2. [Figure 22] FIG. [Diagram 23] FIG. [Figure 24] FIG. [Diagram 25] FIG. [Figure 26] An enlarged view of part E in FIG. [Figure 27] 20 is a cross-sectional view taken along line FF in FIG. 19. [Figure 28] FIG. [Figure 29] FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, one embodiment of the present invention will be described with reference to FIGS.

[0021] In this embodiment, the present invention is applied to a swivel chair for business use (hereinafter simply referred to as a "chair") suitable for use in an office or the like.

[0022] The chair comprises legs A, a support base B which is a support member supported rotatably relative to the legs A, a seat C disposed on the support base B, a backrest E supported so as to be able to tilt backward relative to the support base B via a back support member (not shown), and a backrest surface extension member F and a hanger G which are options which can be selectively attached to the backrest E.

[0023] <<Legs A>> The leg A includes a plurality of leg blades a1 arranged radially, each having a caster a11 at its tip, and a leg support a2 erected at the base end of the leg blade a1.

[0024] The leg support a2 is configured to be extendable and retractable in the vertical direction. The leg support a2 is capable of supporting the support base B by a gas spring (not shown) so that the vertical position can be changed.

[0025] <<Support base B>> The support base B is mainly composed of a support base main body 1 which is integrally formed from synthetic resin. The support base B is attached onto the leg A.

[0026] <Support base body 1> The support base main body 1 comprises a foundation bottom structure 11 having a downward surface and attached to the leg support a2, an inclined bottom wall 12 having a downward surface facing diagonally downward and rearward and extending diagonally downward and forward from the front end of the foundation bottom structure 11, a front bottom wall 13 having a downward surface, extending forward from the front end of the inclined bottom wall 12 and inclined so as to gradually position upward as it moves forward, left and right side walls 14 in an upright position extending upward from the left and right ends of the foundation bottom structure 11, the inclined bottom wall 12, and the front bottom wall 13, respectively, and a front wall 15 in an upright position connecting the front ends of the left and right side walls 14.

[0027] A reaction force generating unit (not shown) is disposed inside the support base main body 1 to generate a reaction force for the backrest E that can tilt backward. The reaction force generating unit is disposed between a reaction force adjusting lever K pivotally supported on the support base B and a back support (not shown) pivotally supported on the support base B and connected to the backrest E. The reaction force generating unit is mainly composed of a spring material.

[0028] A reaction force adjusting lever K, which is an adjustment lever for adjusting the reaction force of the backrest E, is rotatably supported on the support base B.

[0029] <<Reaction force adjustment lever K>> The reaction force adjustment lever K is rotatably supported on the support base 1. The reaction force adjustment lever K is pivotally supported on the support base 1 so that its longitudinal axis is in the left-right direction. The reaction force adjustment lever K is rotated by the user's hand, and the degree of compression of the spring material that constitutes the reaction force generating part can be adjusted in accordance with the rotation.

[0030] The reaction force adjustment lever K is equipped with an operating part k1 which is provided at the tip, which is one end portion, and is gripped by a user to apply a rotational operating force, an intermediate connecting part k2 which is connected to the operating part k1 with its axis js aligned and has a shape in which the outer diameter dimension becomes shorter as it moves away from the operating part k1, and a lever base shaft part k3 which is connected to the intermediate connecting part k2 with its axis js aligned and has a retained shaft part k31 which is a part which is pivotally supported on the support base main body 1.

[0031] The reaction force adjusting lever K is made up of an operating portion k1, an intermediate connecting portion k2, and a lever base shaft portion k3 which are integrally formed from synthetic resin.

[0032] <Operation unit k1> The operation unit k1 includes an operation unit body k11 having a generally cylindrical shape that is open to the outside, and a protruding portion k12 that is a mark portion provided at an end of the operation unit body k11 and extends toward the center of the operation unit body k11. The protruding portion k12 is a single portion that protrudes from the inner peripheral surface of the operation unit body k11 toward the center of the operation unit body k11.

[0033] [Operation unit body k11] The operation unit body k11 can form a substantially cylindrical space s1 inside. The operation unit body k11 is configured such that the outer peripheral surface of the tip portion k111 is positioned in a direction that gradually approaches the tip. In addition, a plurality of grooves k112 for preventing finger slippage are provided along the axis js on the outer peripheral surface of the tip portion k111 of the operation unit body k11.

[0034] A mark recessed portion k114 having a width dimension substantially equal to the thickness dimension of the protruding portion k12 is formed on the outer peripheral surface of the tip portion k111 of the operation portion main body k11 corresponding to the protruding portion k12. That is, the recessed portion k114 is provided on the outer peripheral surface of the tip portion k111 located directly behind the inner peripheral surface of the operation portion main body k11 from which the protruding portion k12 is protruded.

[0035] [Protruding part k12] The protrusion k12 protrudes from the inner circumferential surface of the operation unit main body k11 toward the axis js. The protrusion k12 is in the form of an upright wall extending along the longitudinal direction of the reaction force adjustment lever K. When viewed from the axis js direction, the protrusion k12 has a tip k121 which is a shaped portion that gradually narrows toward the axis js. In this embodiment, the gradually narrowing shaped portion is only present at the tip k121 of the protrusion k12. More specifically, the tip k121 of the protrusion k12 is in the form of a semicircular arc in a side view.

[0036] The protruding portion k12 has an outwardly facing end surface k122 for use as a marker on the outwardly facing end edge of the operation portion main body k11, that is, on the outer side of the opening edge k113 of the operation portion main body k11.

[0037] <Intermediate connection part k2> The intermediate connecting part k2 has a shape in which the outer diameter dimension gradually decreases from the side having the operating part k1 toward the side having the lever base part k3. That is, the intermediate connecting part k2 has a partial cone shape interposed between the operating part k1 and the lever base part k3.

[0038] A substantially conical inner space s2 is formed inside the intermediate connecting part k2, which is continuous with the cylindrical space s1 of the operating part main body k11. A protrusion k12 provided on the operating part main body k11 is connected to the inner peripheral surface of the tip side part of the intermediate connecting part k2, i.e., the inner peripheral surface on the operating part k1 side.

[0039] <Lever base part k3> The lever base shaft portion k3 is provided with a retained shaft portion k31 which is connected to the intermediate connecting portion k2 with its axis js aligned and journaled on the support base B, an engaging protrusion k32 which can engage with a protrusion (not shown) for regulating the rotation range provided on the support base B, and a cam portion k33 which can engage with a reaction force generating portion (not shown) arranged inside the support base B.

[0040] A plurality of held shaft portions k31 are arranged on the lever base shaft portion k3. Among the plurality of held shaft portions k31 arranged on the lever base shaft portion k3, the diameter of the held shaft portion k31 at the base end is set to be the smallest, and the diameter of the held shaft portion k31 at the tip side (operation portion k1 side) is set to be the largest. In other words, the lever base shaft portion k3 is arranged with a plurality of held shaft portions k31 having different diameters from the base end to the tip side, and the diameter at the tip side is set to be larger than that at the base end side.

[0041] The engaging protrusions k32 are disposed at two positions on the left and right sides of the lever base shaft k3, spaced apart from each other. The engaging protrusions k32 are adapted to engage with a protrusion (not shown) for restricting the rotation range provided on the support base B, thereby restricting the rotation range of the reaction force adjusting lever K, which receives the operating force from the user, around the axis js.

[0042] The cam portions k31 are disposed at two positions on the left and right sides of the lever base shaft portion k3, spaced apart from each other.

[0043] <<Location C>> The seat C includes a seat support c1 and a seat body c2 that is provided on the seat support c1 so that its front-rear position can be changed.

[0044] An operating piece L that acts on a gas spring (not shown) and can expand and contract the leg support a2 in the up and down direction is pivotally supported at the bottom of the seat support c1 so as to be capable of flapping.

[0045] The seat body c2 is configured to be able to slide in the front-rear direction relative to the seat support c1.

[0046] <<Back support>> The back support, not shown, is interposed between the support base B and the backrest E. The back support comprises a pair of left and right arms that extend in the front-rear direction and are pivotally supported on the support base main body 1 via a main shaft, not shown, and a connecting member that connects the rear parts of the pair of left and right arms. The connecting member is provided with a nut portion to which a screw for attaching the backrest E is screwed. In other words, a backrest attachment portion to which the backrest E is attached is provided at the rear part of the back support.

[0047] A rearward tilt degree setting lever H, which can selectively set the rearward tilt degree of the backrest E, is rotatably supported on the back support body.

[0048] The back support is covered and concealed by a cover body I which is integrally formed from a synthetic resin.

[0049] <<Backrest E>> The backrest E comprises a back frame M attached to the backrest mounting portion of the back support, and a mesh-like stretching member P stretched over the back frame M. The backrest E has a backrest surface pm that supports the back of a seated person from behind, and is formed by the stretching member P mainly made of mesh fabric.

[0050] The chair of this embodiment is configured so that an optional backrest surface extension member F and a hanger G can be selectively attached to the upper frame material 3 of the backrest E.

[0051] <Back frame M> The back frame M comprises left and right side frame members 2 each having a tension member mounting groove mz opening outward, an upper frame member 3 having a tension member mounting groove mz opening upward and connecting the upper parts of the left and right side frame members 2, a lower frame member 4 connecting the lower parts of the left and right side frame members 2, and an intermediate connecting frame member 5 having a tension member mounting groove mz opening downward and connecting the left and right side frame members 2 together while forming an upper cavity sa between the upper frame member 3 and a lower cavity sb between the lower frame member 4.

[0052] The left and right side frame members 2, the upper frame member 3, and the lower frame member 4 are integrally molded from synthetic resin. The intermediate connecting frame member 5 is attached to the left and right side frame members 2 with screws.

[0053] The back frame M comprises an upper frame-shaped portion w1 which is formed with an upper cavity sa therein by left and right side frame members 2, an upper frame member 3, and an intermediate connecting frame member 5, and a lower frame-shaped portion w2 which is formed with a lower cavity sb therein by left and right side frame members 2, a lower frame member 4, and an intermediate connecting frame member 5.

[0054] The backrest E in this embodiment is configured such that a tension member P capable of forming a backrest surface pm is tensioned to an upper frame portion w1 which is a frame portion provided on a back frame M.

[0055] [Left and right side frame material 2] The left and right side frame members 2 extend in the vertical direction. On the outer surfaces of the left and right side frame members 2, tension member attachment grooves mz are formed, which continue from the upper ends of the left and right side frame members 2 to a height position approximately corresponding to the lower edges of the intermediate connecting frame members 5.

[0056] [Top frame material 3] The upper frame material 3 extends in the left-right direction. The upper frame material 3 has an outer frame portion 31 in which a tension member mounting groove mz that opens upward for mounting a tension member P is formed, and an inner frame portion 32 disposed below the outer frame portion 31. The upper frame material 3 is provided with a nut holding recess nt in which a nut member J for mounting an option can be held, as will be described in detail later.

[0057] The outer frame portion 31 constitutes the upper portion of the upper frame material 3. The front surface of the outer frame portion 31 forms the portion that is attached to the rear surface of the tension member P, i.e., the portion that backs the tension member P.

[0058] The inner frame portion 32 constitutes the lower portion of the upper frame material 3. The inner frame portion 32 is located more inward than the outer frame portion 31. In other words, the inner frame portion 32 is provided in a location that is covered by the tension member P when viewed from the front.

[0059] The inner frame portion 32 includes a hanging wall 321 that is arranged to hang downward from the rear of the outer frame portion 31, a lower end wall 322 that extends forward from the lower end of the hanging wall 321, and a plurality of connecting walls 323 that form upright walls connecting between the lower end wall 322 and the outer frame portion 31, and between the lower end wall 322 and the hanging wall 321.

[0060] The back surface of the hanging wall 321 is substantially flush with the back surface of the outer frame portion 31. The bottom end wall 322 is provided at a distance in the up-down direction from the outer frame portion 31. The connecting walls 323 are provided to increase the connecting strength between the bottom end wall 322 and the outer frame portion 31, and a plurality of them are provided at regular intervals in the left-right direction.

[0061] The inner frame portion 32 is provided with a nut holding recess nt that is formed with an upper opening portion kh1 that is open upward, a lower opening portion kh2 that is open downward, and a front opening portion kh3 that is open forward and that can hold the nut member J. The nut holding recess nt is provided at a plurality of positions on the inner frame portion 32.

[0062] The nut retaining recess nt is provided in the lower end wall 322 of the inner frame portion 32. The nut retaining recess nt has left and right standing wall portions nt1 and a rear standing wall portion nt2 connecting rear portions of the left and right standing wall portions nt1. The nut retaining recess nt has a generally U-shaped hole shape that is open to the front when viewed from the bottom.

[0063] The nut retaining recess nt is formed by left and right upright wall portions nt1 and a rear upright wall portion nt2, which define an upper opening portion kh1 that is open upward, a lower opening portion kh2 that is open downward, and a front opening portion kh3 that is open forward.

[0064] In addition, the nut retaining recess nt forms a portion that can form an upper opening portion kh1 by the upper edges of the left and right upright wall portions nt1 and the upper edge of the rear upright wall portion nt2, and also forms a flange engagement portion nt3 that can engage with the underside of the flange portion j2 of the nut member J.

[0065] A gap sk capable of accommodating the flange portion j2 of the nut member J is formed between the nut holding recess nt and the outer frame portion 31.

[0066] In this embodiment, the inner frame portion 32 is provided with four nut holding recesses nt spaced apart in the left-right direction. The pair of nut holding recesses nt located on both the left and right outer sides are used when attaching a backrest surface extension member F for extending the backrest surface pm, and the pair of nut holding recesses nt located on both the left and right inner sides are used when attaching a hanger G for hanging clothes.

[0067] The nut member J held in the nut holding recess nt is made of metal. The nut member J includes a boss portion j1 ​​that is accommodated in the enclosed space of the nut holding recess nt and has a screw groove j11 on its inner peripheral surface, and a flange portion j2 that is connected to the boss portion j1 ​​and can engage with a flange portion engagement portion nt3 whose lower surface forms the upper open portion kh1.

[0068] The nut member J has a generally T-shape. That is, the flange portion j2 extends longitudinally outward in the left-right direction from the upper end of the generally cylindrical boss portion j1.

[0069] The method of holding the nut member J in the nut holding recess nt provided in the backrest E and attaching the optional backrest surface extension member F and optional hanger G will be described in detail later.

[0070] [Bottom frame material 4] The lower frame member 4 has a portion that connects the lower portions of the left and right side frame members 2 and is connected to the back support member. The lower frame member 4 is provided with a back support member connecting portion 41 that is recessed and open forward, for fitting externally to a backrest mounting portion provided on the back support member and connecting the backrest mounting portion.

[0071] [Intermediate connection frame material 5] The intermediate connecting frame member 5 extends in the left-right direction. The intermediate connecting frame member 5 is installed between the portions of the left and right side frame members 2 that are tilted forward when viewed from the side. The intermediate connecting frame member 5 is separate from the other frame members that make up the back frame M, i.e., the left and right side frame members 2, the upper frame member 3, and the lower frame member 4.

[0072] The left and right ends of the intermediate connecting frame member 5 are screwed to the left and right side frame members 2. The intermediate connecting frame member 5 has a curved shape that is convex toward the rear in a plan view. The intermediate connecting frame member 5 is formed with a tension member mounting groove mz that opens downward.

[0073] <Upholstery material P> The upholstery member P is mainly made of a mesh-like fabric capable of forming the backrest surface pm.

[0074] The tensile member P is adapted to be attached at its peripheral portion to a tensile member attachment groove mz provided in the upper frame-shaped portion w1 of the back frame M. The tensile member P is stretched over the front side of the upper frame-shaped portion w1 of the back frame M.

[0075] <<Backrest extension member F>> The backrest surface extension member F is for providing an extended backrest surface fm as a contact surface that can contact the user on the backrest surface pm formed by the backrest E. The backrest surface extension member F in this embodiment is called a "shoulder support" because the user's shoulders can mainly contact the extended backrest surface fm.

[0076] The backrest surface extension member F includes a pad body f1 having an extended backrest surface fm, the front surface of which is a contact surface that can come into contact with a user, and a base body f2 that can support the pad body f1.

[0077] The backrest surface extension member F has an upper frame material arrangement recess fu formed between the lower part of the base body f2 and the lower end part of the pad body f1, the upper frame material arrangement recess fu being open to the front and both the left and right sides.

[0078] The backrest surface extension member F is provided with a movement restricting portion ks, which is located on the rear side of the upper frame material 3 in the backrest E and can restrict forward movement by engaging with the rear portion of the upper frame material 3, at a position facing the upper frame material arrangement recess fu.

[0079] <Pad body f1> The pad body f1 includes a pad body main body f3 attached to a pad body attachment portion f6 provided on the base body f2, and a front skin f4 covering the front surface and peripheral edge portion of the pad body main body f3.

[0080] The pad body f1 has a generally rectangular shape with its elongated sides in the left-right direction when viewed from the front. The pad body f1 has a generally symmetrical shape when viewed from the front. The edges of both the left and right sides of the pad body f1 are gently curved so as to convex outward when viewed from the front. The extended backrest surface fm, which is the front surface of the pad body f1, is set to be generally flush with the backrest surface pm formed by the upholstery member P.

[0081] The vertical dimension of the pad body f1 is shorter than the vertical dimension of the base body f2. The position of the upper edge of the pad body f1 is approximately aligned with the position of the upper edge of the base body f2. The shape of the side edge of the pad body f1 in a front view is approximately aligned with the shape of the side edge at the same height position of the base body f2. The lower edge of the pad body f1 is set at a position that approximately abuts against the upper frame member 3.

[0082] [Pad body f3] The pad body f3 includes a pad base f31 formed of synthetic resin in the shape of a generally upright plate, and a cushion f32 made of urethane foam attached to the front surface of the pad base f31.

[0083] The pad base f31 has a pair of hook engaging portions f311 spaced apart from each other in the left-right direction at the center of the back side of the pad base f31 in the vertical direction. The hook engaging portion f311 has an engaging hole f314 that is open in the vertical direction.

[0084] The hook engaging portion f311 has an engaging hole f314 penetrating in the vertical direction, which is formed by left and right protruding walls f312 protruding rearward and a connecting wall f313 connecting the rear portions of the left and right protruding walls f312. The hook engaging portion f311 can engage with the base body f2 by inserting a hook f61, which is an engaging portion protruding from the pad body mounting portion f6 of the base body f2, into the engaging hole f314.

[0085] The lower part of the rear side of the pad base f31 is provided with left and right fitting protrusions f315 and a central fitting protrusion f316 as engagement parts at three locations on the left, right and center. Each fitting protrusion f315, f316 is substantially arrow-shaped and protrudes rearward. Each fitting protrusion f315, f316 can be engaged with a protrusion fitting part f62 as an engagement part provided on the pad body mounting part f6 of the base body f2. The left and right fitting protrusions f315 are set in a different position from the central fitting protrusion f316. More specifically, the left and right fitting protrusions f315 are set in a position rotated 90 degrees from the central fitting protrusion f316 in rear view.

[0086] [Front skin material f4] The front skin f4 is made of a fabric having an area larger than the front part of the pad body f3. The edge part f4e of the front skin f4 can be stored between the pad body f3 and the base body f2 so as not to be visible from the outside. The front skin f4 can form an extended backrest surface fm provided on the backrest surface pm of the upholstery member P.

[0087] <Base body f2> The base body f2 comprises a base plate-shaped portion f5 having an approximately upright plate shape, a pad body mounting portion f6 provided on the front side of the base plate-shaped portion f5 and to which the pad body f1 is attached, an upper frame member mounting portion f7 provided below the pad body mounting portion f6 and attached to the upper frame member 3 using a fastener screw v1, and a rear skin material f9 that covers the peripheral portion and rear portion of the base plate-shaped portion f5.

[0088] The base plate portion f5, the pad body mounting portion f6, and the upper frame member mounting portion f7 that constitute the base body f2 are integrally formed from synthetic resin.

[0089] In this embodiment, the backrest surface extension member F is configured so that only the rear skin material f9 covering the base plate portion f5 of the base body f2 can be seen in the rear view. In other words, the backrest surface extension member F is configured so that no members other than the rear skin material f9 can be seen in the rear view.

[0090] [Base plate part f5] The base plate portion f5 has a generally rectangular shape with its elongated sides in the left-right direction in rear view. The edges of the left and right sides of the base plate portion f5 are gently curved so as to convex outward in rear view. The rear surface of the base plate portion f5 is covered with a rear skin material f9.

[0091] The front side of the base plate-shaped portion f5 is provided with an upper horizontal rib f52 extending in the left-right direction, the tip of which can abut against the rear surface of the pad base f31, and a plurality of vertical ribs f53 extending in the up-down direction, the tip of which can abut against the rear surface of the pad base f31. The vertical ribs f53 are arranged at intervals in the left-right direction. A lower horizontal rib f54 extending in the left-right direction, the tip of which can abut against the upper frame material 3 of the backrest E, is provided at the lower part of the front side of the base plate-shaped portion f5.

[0092] In this embodiment, the movement restriction portion ks is mainly composed of the components located behind the upper frame material 3, i.e., the tip of the lower horizontal rib f54 and the tip of the vertical rib f53 located below the lower horizontal rib f54, and can restrict the forward movement of the backrest surface extension member F by engaging with the back surface of the upper frame material 3.

[0093] [Pad body mounting part f6] The pad body mounting portion f6 has a hook f61 protruding at a position corresponding to the hook engagement portion f311 of the pad base f31, and a protruding engagement portion f62 protruding at positions corresponding to the left, right and center engagement protrusions f316 of the pad base f31.

[0094] The pad body f1 is attached to the base body f2 by engaging the hook engagement portion f311 with the hook f61 provided on the pad body mounting portion f6, and then engaging the left, right and central engaging protrusions f315, f316 with the protrusion engaging portions f62 provided on the pad body mounting portion f6.

[0095] [Upper frame mounting part f7] The upper frame member mounting portion f7 is mainly composed of a portion protruding forward from the lower end of the base plate portion f5. The upper frame member mounting portion f7 has an upward surface f71 that extends in the left-right direction and serves as the mounting base surface for the upper frame member 3.

[0096] The upper frame member mounting portion f7 has two screw holes h1 that penetrate vertically at the left and right. The backrest surface expansion member F is configured to be mounted to the upper frame member 3 by screwing the screw v1 inserted through the screw hole h1 into the nut member J disposed in the nut holding recess nt in the upper frame member 3.

[0097] The upper frame material mounting portion f7 has a convex wall portion f72 at the upper end of the front part corresponding to the portion where the screw insertion hole h1 is formed, which can be positioned in the front opening portion kh3 of the nut retaining recess nt provided in the upper frame material 3.

[0098] A storage groove f8 that is open downward and outward and can store the edge portion f9e of the rear skin f9 is formed in the lower part of the base body f2, i.e., between the upper frame member mounting portion f7 and the base plate-shaped portion f5. Groove-forming walls f73 are erected at the rear ends of both sides of the upper frame member mounting portion f7 to form the storage groove f8 between them and the peripheral portion of the base plate-shaped portion f5.

[0099] In addition, the front surface of the groove forming wall f73 can abut against the rear surface of the upper frame material 3, and also serves as a movement restricting portion ks that can restrict the forward movement of the backrest surface extension member F.

[0100] [Back skin material f9] The rear skin f9 is made of a material having an area larger than the rear surface of the base plate portion f5. The edge portion f9e of the rear skin f9 can be accommodated between the base plate portion f5 and the pad body f1, and can also be accommodated in an accommodating groove f8 provided between the lower peripheral edge of the base plate portion f5 and the upper frame member mounting portion f7.

[0101] << Hanger G >> The hanger G is for hanging the user's clothes, etc. The hanger G is attached to the upper frame member 3 of the back frame M.

[0102] The hanger G comprises a hanger body g1 extending in the left-right direction for hanging clothes, etc., a pair of left and right hanger legs g2 extending downward from the underside of the hanger body g1 and extending forward at the lower part, and a base portion g3 which connects the lower ends of the left and right hanger legs g2 and is provided with an upper frame member mounting portion g7 which is attached to the upper frame member 3.

[0103] The base portion g comprises a base portion main body g4 having an upper frame material mounting portion g7, and an upright wall g5 serving as a movement restricting portion ks that is erected at the rear of the base portion main body g4 and can engage with the rear surface of the upper frame material 3.

[0104] The upper frame material mounting portion g7 extends in the left-right direction and has an upward surface g71 which serves as the mounting base surface for the upper frame material 3.

[0105] The upper frame member mounting portion g7 is provided with two screw insertion holes h2 penetrating in the vertical direction at the left and right positions. The hanger G is configured to be mounted to the upper frame member 3 by screwing the screw v2 inserted into the screw insertion hole h2 into the nut member J disposed in the nut holding recess nt in the upper frame member 3.

[0106] The upper frame material mounting portion g7 has a convex wall portion g72 at the upper end of the front part corresponding to the portion where the screw insertion hole h2 is formed, which can be positioned at the front opening portion kh3 of the nut retaining recess nt provided in the upper frame material 3.

[0107] <<How to install the option (backrest extension part F)>> The chair of this embodiment is applied with a mounting structure that makes it easy to mount options to the backrest E. Hereinafter, a method of mounting the options to the upper frame material 3 of the backrest E will be described using the backrest surface extension member F as a specific example.

[0108] First, the nut member J is held in the nut holding recess nt that is open forward and provided in the upper frame member 3. A tension member P is stretched and provided in advance on the front side of the upper frame-shaped portion w1 of the back frame M.

[0109] The worker passes the approximately T-shaped nut member J through the upper cavity sa surrounded by the upper frame-shaped portion w1 from the rear to the front, and then holds the nut member J in the nut holding recess nt which is open to the front.

[0110] The boss portion j1 ​​of the nut member J is accommodated in the nut holding recess nt through the front opening portion kh3. The flange portion j2 of the nut member J is accommodated in the gap sk between the nut holding recess nt and the outer frame portion 31. The flange portion j2 of the nut member J engages with the flange portion engagement portion nt3, which is the portion that forms the upper opening portion kh1 in the nut holding recess nt, and cannot move downward. In other words, the nut member J is provisionally positioned relative to the upper frame material 3 by having the boss portion j1 ​​accommodated in the nut holding recess nt and the flange portion j2 disposed in the gap sk.

[0111] Next, the backrest surface extension member F is moved from rear to front, and disposed at a position where the upper frame material disposition recess fu surrounds the upper frame material 3.

[0112] Then, a screw v1 is inserted from the bottom to the top through a screw insertion hole h1 provided in the upper frame member mounting portion f7 of the backrest surface extension member F, and the screw v1 is screwed into the boss portion j1 ​​of the nut member J. By screwing the screw v1 into the nut member J, the upper frame member mounting portion f7 of the backrest surface extension member F and the inner frame portion 32 of the upper frame member 3 are fastened together.

[0113] Using the above mounting method, the backrest surface extension member F can be attached to the upper frame material 3 of the backrest E.

[0114] The nut holding recess nt provided in the upper frame material 3 is open in the forward and vertical directions, making it easy for an operator to attach (temporarily place) the nut member J. The operator can properly hold the nut member J in the nut holding recess nt by simply feeling the inner frame portion 32 of the upper frame material 3 from the rear side of the backrest E without having to closely check the nut holding recess nt which is covered by the upholstery member P and difficult to see.

[0115] In addition, the backrest surface extension member F is provided with a movement restriction portion ks that can restrict forward movement. Therefore, even if the backrest surface extension member F is pressed forward, the nut member J cannot move forward from the nut holding recess nt that is open to the front side.

[0116] With the above-described embodiment, it is possible to provide a chair having an operating unit main body k11 with an approximately cylindrical outer shape that suppresses complexity, while having a reaction force adjustment lever K that can preferably perform an indicator function of indicating the rotation posture by means of the protrusion k12.

[0117] Furthermore, in the above-described embodiment, the nut member J can be held in the nut retaining recess nt which is open above, below and to the front, making it possible to provide a chair having a suitable configuration in which options such as a backrest surface extension member F can be attached to the backrest E.

[0118] In the above-described embodiment, the backrest surface extension member F is attached to the upper frame member 3 of the backrest E. The backrest surface extension member F is configured such that only the rear skin material f9 covering the base plate-shaped portion f5 can be seen in the rear view, so that a preferable appearance based on the rear skin material f9 can be achieved in the rear view.

[0119] As described above, the chair according to this embodiment includes the reaction force adjusting lever K, which is an adjusting lever rotatably supported on the support base B, which is a supporting member.

[0120] The reaction force adjustment lever K has an operation part k1 at one end which is gripped by a user to apply a rotational operation force. The operation part k1 has an operation part main body k11 having a generally cylindrical shape that is open to the outside, and a protrusion k12 that protrudes from the inner peripheral surface of the operation part main body k11 toward the center of the operation part main body k11.

[0121] As a result, it is possible to provide a chair having a reaction force adjustment lever K that has a substantially cylindrical outer shape with reduced complexity, while also being able to optimally perform the indicator function of indicating the rotation posture.

[0122] That is, the operation unit k1 includes a generally cylindrical operation unit body k11 that is open to the outside. Therefore, the operation unit k1 has a suitable configuration that is not only unlikely to catch on articles such as clothing or personal belongings, but also unlikely to break even when subjected to an external force.

[0123] Furthermore, since the protrusion k12 protrudes from the inner peripheral surface of the operating unit body k11 toward the center of the operating unit body k11, the user can easily visually grasp the current state of the rotational posture.

[0124] In other words, with the reaction force adjustment lever K provided on the chair of this embodiment, a user can easily grasp the rotational posture of the reaction force adjustment lever K by visually checking the position of the protrusion k12 of the reaction force adjustment lever K before actually sitting down and leaning against the backrest E.

[0125] The protruding portion k12 extends along the longitudinal direction of the reaction force adjusting lever K and has a standing wall shape.

[0126] For this reason, the protrusion k12 is suitably provided in a manner that is not easily broken with respect to the operation portion main body k11.

[0127] The protruding portion k12 has an outwardly facing end surface k122 serving as a marker at a position outside the outwardly facing end edge of the operation portion main body k11.

[0128] Therefore, the end face k122 of the protruding portion k12 is easily visible to the user, and allows the user to easily grasp the rotational attitude of the reaction force adjusting lever K.

[0129] The protruding portion k12 has a shape that gradually narrows toward the axis js when viewed from the axis js direction.

[0130] Therefore, the shape of the protrusion k12 is a suitable shape for indicating the rotational attitude of the reaction force adjusting lever K without causing any sense of discomfort.

[0131] A mark recess k114 having a width dimension substantially equal to the thickness dimension of the protrusion k12 is formed on the outer circumferential surface of the operation portion main body k11 corresponding to the protrusion k12.

[0132] As a result, not only the protrusion k12 but also the recessed portion k114 cooperate as a position to direct the user's attention, thereby enabling the user to more appropriately indicate the rotational posture of the reaction force adjustment lever K.

[0133] The reaction force adjustment lever K comprises an operating part k1, an intermediate connecting part k2 connected to the operating part k1 with its axis js aligned therewith and having an outer diameter dimension that decreases with increasing distance from the operating part k1, and a lever base shaft part k3 connected to the intermediate connecting part k2 with its axis js aligned therewith and having a portion that is pivotally supported on a support base B, which is a support member.

[0134] For this reason, the reaction force adjustment lever K has a suitable configuration that allows the user to easily rotate the operating part k1, and also has a suitable configuration that allows it to be rotatably supported on the support base B.

[0135] The operating portion k1, the intermediate connecting portion k2, and the lever base shaft portion k3 are integrally formed from synthetic resin.

[0136] Therefore, the operating portion k1 can be preferably formed, and the number of parts constituting the reaction force adjusting lever K can be preferably reduced.

[0137] A reaction force generating portion is provided on the support base B, which generates a reaction force for the backrest E that can be tilted backward, and a reaction force adjusting lever K engages with the reaction force generating portion.

[0138] For this reason, the reaction force adjustment lever K, which is easily operated by the user, is endowed with an indicator function that indicates the rotational position.

[0139] It should be noted that the present invention is not limited to the embodiment described above in detail.

[0140] The adjustment lever may be used for any purpose as long as it is rotatably supported on a support member that constitutes the chair.

[0141] The support member is not limited to a member constituting a support base, but may be any member constituting a chair, such as a seat, a back support, or a backrest.

[0142] The protrusion may be any shape as long as it protrudes from the inner peripheral surface of the operation portion body.

[0143] The outwardly facing end surface of the protrusion serving as a marker may be disposed at a position that substantially coincides with the edge of the opening of the operation portion main body.

[0144] The adjustment lever may be one in which the operating portion, the intermediate connecting portion, and the lever base shaft portion are not integrally formed from synthetic resin.

[0145] The adjustment lever may be configured such that the operation portion and the other portions are separate.

[0146] Furthermore, the specific configuration of each part is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the present invention. [Explanation of symbols]

[0147] B…Support base (support member) K…Reaction force adjustment lever (adjustment lever) k1…Operation unit k11…Operation unit body k12…Protrusion

Claims

1. A chair comprising an adjustment lever rotatably supported on a support member, the adjustment lever has an operating portion at one end thereof which is gripped by a user to apply a rotational operating force thereto; The operation unit includes an operation unit body having a generally cylindrical shape that is open outward, and a mark portion that is provided at an end of the operation unit body and extends toward a center of the operation unit body, the mark portion is a protrusion protruding from an inner circumferential surface of the operation unit body toward a center of the operation unit body, The operation unit body is configured such that an outer circumferential surface of a tip portion is gradually moved toward the tip, The chair has a recessed marker portion formed on the outer peripheral surface of the tip portion at a position corresponding to the protrusion, the recessed portion having a width dimension approximately the same as the thickness dimension of the protrusion, and a plurality of grooves for preventing fingers from slipping are provided along the axis at other positions.

2. 2. The chair according to claim 1, wherein the protrusion is in the form of an upright wall extending along the longitudinal direction of the adjustment lever.

3. 3. The chair according to claim 1, wherein the protrusion has an outwardly facing end surface for use as a marker located outside an outwardly facing end edge of the operating portion body or at a position substantially coinciding with the end edge.

4. 4. The chair according to claim 1, 2 or 3, wherein the protruding portion has a shape portion which gradually narrows toward the axis.

5. 5. A chair as claimed in claim 1, 2, 3 or 4, wherein the adjustment lever comprises: the operating portion; an intermediate connecting portion which is connected to the operating portion with its axis aligned and has an outer diameter dimension which becomes smaller as it moves away from the operating portion; and a lever base portion which is connected to the intermediate connecting portion with its axis aligned and has a portion which is pivotally supported on the support member.

6. 6. The chair according to claim 5, wherein the operating portion, the intermediate connecting portion and the lever base shaft portion are integrally formed from a synthetic resin.

7. 7. The chair according to claim 1, 2, 3, 4, 5 or 6, wherein the support member is a support base attached onto the legs and capable of supporting the backrest so as to be capable of tilting backward.

8. The support base is provided with a reaction force generating unit that generates a reaction force of the backrest that can be tilted backward, 8. The chair according to claim 7, wherein the adjustment lever is a reaction force adjustment lever which engages with the reaction force generating portion.

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