Armrest and chair

Abstract

To provide an armrest which can preferably execute an operation for changing a vertical position of an armrest body.SOLUTION: An armrest K used by being attached to a chair body, includes: an elbow support 5 attached to the chair body; and an armrest body KH supported to the elbow support 5 in a vertically movable manner. The armrest body KH includes: an elbow pad support 6; and an elbow pad 7 provided such as to be slidable in a front-rear direction with respect to the elbow pad support 6. An operation lever R for operating the elbow pad body KH in a vertically movable manner is provided to the elbow pad 7.SELECTED DRAWING: Figure 22

Description

[Technical field]

[0001] The present invention relates to an armrest and to a chair having an armrest mounted thereon. [Background technology]

[0002] 2. Description of the Related Art Various chairs for use in offices have been conventionally known (see, for example, Patent Document 1).

[0003] Among chairs of this type, there are those equipped with armrests that are configured so that the armrests can slide forward and backward and also so that the position of the armrests can be changed in the up and down direction.

[0004] However, in conventional armrests, an operating lever for changing the position of the armrest in the vertical direction is provided in a component part of the armrest that is located below the armrest that moves back and forth.

[0005] For this reason, conventional armrests have a configuration that makes it difficult to operate the operating lever while placing the hands on the armrests. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2019-42081 A Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made in light of the above-mentioned circumstances, and is capable of providing an armrest that allows at least the operation of changing the up and down position of the armrest body to be performed preferably, and a chair equipped with such an armrest. [Means for solving the problem]

[0008] That is, the present invention has the following configuration.

[0009] The invention described in claim 1 is an armrest that is attached to a chair body and used, comprising an arm support attached to the chair body and an armrest main body supported on the arm support so that its vertical position can be changed, the armrest main body comprising an armrest support part and an armrest arranged so that it can slide forward and backward relative to the armrest support part, and an operating lever for operating the armrest main body so that its vertical position can be changed is arranged on the armrest.

[0010] The invention described in claim 2 is the armrest described in claim 1, wherein the operating lever is supported rotatably relative to the armrest.

[0011] The invention recited in claim 3 is the armrest recited in claim 1, wherein the operating lever is disposed at a front end portion of the armrest.

[0012] The invention described in claim 4 is an armrest as described in claim 1, in which the elbow support has a plurality of engaged portions arranged in the vertical direction, and an engaging member arranged on the elbow pad support portion selectively engages with the plurality of engaged portions to determine the vertical position of the armrest body relative to the elbow support, and the operating force applied to the operating lever is transmitted to the engaging member via a wire member.

[0013] The invention described in claim 5 is an armrest as described in claim 4, wherein the elbow rest support portion has an arrangement space in which a part of the wire member can be arranged, the elbow rest comprises an elbow rest base that rotatably supports the operating lever, and an elbow rest pad arranged on the elbow rest base, and has an arrangement space between the elbow rest base and the elbow rest pad in which a part of the wire member can be arranged, and the elbow rest base has a wire member communication hole that penetrates in the vertical direction and allows a part of the wire member to pass through.

[0014] The invention described in claim 6 is an armrest as described in claim 4, which is provided with an engagement unit attached to the elbow rest support portion, the engagement unit comprising a unit base attached to the elbow rest support portion, an engagement member arranged to be movable relative to the unit base between an engagement position at which it can engage with the engaged portion and a retracted position retracted from the engagement position, and a spring arranged between the unit base and the engagement member for urging the engagement member toward the engagement position.

[0015] The invention described in claim 7 is an armrest as described in claim 1, wherein the elbow rest comprises an elbow rest base that rotatably supports the operating lever and an elbow rest pad arranged on the elbow rest base, and the elbow rest pad is provided with an elastic biasing portion that engages with the operating lever and biases the operating lever in the direction of its initial position.

[0016] The invention described in claim 8 is the armrest described in claim 1, wherein an elbow rest guide mechanism is provided between the elbow rest support part and the elbow rest, which slides the elbow rest on a predetermined trajectory between a most forward position and a most rearward position.

[0017] The invention as recited in claim 9 is a chair comprising a chair body and an armrest as recited in any one of claims 1 to 8 attached to the chair body. Effect of the Invention

[0018] As described above, according to the present invention, it is possible to provide an armrest that allows for preferably performing operations to change the up and down position of the armrest body, and a chair equipped with such an armrest. [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. [Figure 13] FIG. [Figure 14] FIG. [Figure 15] FIG. [Figure 16] FIG. [Figure 17] FIG. [Figure 18] FIG. [Figure 19] FIG. [Figure 20] FIG. [Figure 21] FIG. [Figure 22] FIG. [Diagram 23] FIG. [Figure 24] 5 is an explanatory diagram of the operation of the elbow pad in the embodiment. [Diagram 25] 5 is an explanatory diagram of the operation of the elbow pad in the embodiment. [Figure 26] 5 is an explanatory diagram of the operation of the elbow pad in the embodiment. [Figure 27] 5 is an explanatory diagram of the operation of the elbow pad in the embodiment. [Figure 28]5 is an explanatory diagram of the operation of the elbow pad in the embodiment. [Figure 29] 5 is an explanatory diagram of the operation of the elbow pad in the embodiment. [Diagram 30] FIG. [Diagram 31] FIG. [Diagram 32] FIG. [Diagram 33] Cross-sectional view taken along line AA in Figure 30. [Diagram 34] FIG. [Diagram 35] 35 is a view taken in the direction of arrow B in FIG. 34. [Diagram 36] Cross-sectional view taken along line CC in Figure 30. [Figure 37] 37 is a cross-sectional view corresponding to FIG. 36, showing the seat tilted forward. [Figure 38] Cross-sectional view of line DD in Figure 30. [Figure 39] 39 is a cross-sectional view corresponding to FIG. 38, showing the seat tilted forward. [Diagram 40] FIG. [Diagram 41] FIG. [Diagram 42] FIG. [Diagram 43] FIG. [Diagram 44] Cross-sectional view taken along line EE in Figure 41. [Diagram 45] FIG. [Figure 46] FIG. [Figure 47] FIG. [Figure 48] FIG. [Figure 49] FIG. [Figure 50] FIG. [Figure 51] FIG. [Figure 52]FIG. [Diagram 53] Cross-sectional view of line FF in Figure 2. [Figure 54] Enlarged view of part G in Figure 53. [Figure 55] FIG. 11 is a central cross-sectional view showing a headrest according to another embodiment. [Figure 56] FIG. [Figure 57] FIG. [Figure 58] FIG. 4 is a partially enlarged cross-sectional view illustrating a vertical position changing mechanism in the embodiment. 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 rotatable support base B attached to the upper ends of the legs A, a seat C disposed on the support base B, a back support D rotatably supported on the support base B via a main shaft j1 and having a seat engagement shaft j3 disposed in front of the main shaft j1 and capable of engaging with the seat C, a backrest E supported by the back support D, a headrest I supported by the backrest E, and left and right armrests K attached to the seat C.

[0023] The chair is provided with a weight-sensing rocking mechanism Rc configured to lift the seat C upward by the seat engagement axis j3 in conjunction with the backward tilting movement of the back support D, and a seat forward tilting mechanism G capable of changing the position of the seat C around the seat engagement axis j3 between a normal position (M) in which the seat surface is approximately horizontal and a forward tilted position (F) which is tilted further forward than the normal position (M).

[0024] The chair body is mainly composed of legs A, a support base B, a seat C, a back support D, and a backrest E. That is, the chair of this embodiment includes a chair body, and armrests K and a headrest I attached to the chair body. The backrest E includes a lumbar support e4 that is detachable from a front frame e2, which is a back frame, without using a fastener.

[0025] Each component of the chair will be described in detail below.

[0026] <<Legs A>> The leg A has a plurality of leg blades a1 with casters a3 at the tips, and leg supports a2 erected at the base ends of the leg blades a1. The leg supports a1 include a gas spring (not shown). The leg supports a1 can be extended and retracted in the vertical direction by a seat lift mechanism (not shown).

[0027] <<Support base B>> The support base B supports the seat C, the back support D, and the backrest E.

[0028] The support base B is mainly composed of a support base body b1 which is an upwardly open integrally molded synthetic resin product. The support base body b1 is connected to the upper end of the leg support a2.

[0029] The support base main body b1 comprises a bottom wall portion b2 connected to the upper end of the leg support a2, left and right side wall portions b3 erected from both left and right ends of the bottom wall portion b2, and a front wall portion b4 erected from the front end of the bottom wall portion b2 and disposed between the front ends of the left and right side wall portions b3.

[0030] The left and right side walls b3 are provided with front axle support parts b5 that can support the front axle j2 so that it can slide in conjunction with the operation of the locking mechanism Rc. The front axle support part b5 is provided in the shape of a long hole that extends vertically and is tilted backward. The support base B can support the front part of the seat C so that it can sink down via the front axle j2 and the components of the seat forward tilting mechanism G.

[0031] <<Location C>> The seat C is disposed on the support base B.

[0032] The seat C is arranged so that it can be moved and changed between a normal position (M) and an upward movement position (not shown) moved upward and rearward from the normal position (M) by activation of a weight-sensing rocking mechanism Rc.

[0033] The seat C is disposed so that it can be moved and changed in position between a normal position (M) and a forward-tilting position (F) that is tilted further forward than the normal position (M) by actuating a seat forward-tilting mechanism G.

[0034] The seat C is made of synthetic resin and has a seat engagement shaft holding portion 16 which is a shaft holding portion capable of holding the seat engagement shaft j3, and is equipped with a seat holder c1 having an upper spring receiving portion 21a which receives the upper end portion of the spring wg which constitutes the seat forward tilt mechanism G, and a seat body c2 which has a seating surface and is supported by the seat holder c1.

[0035] The front part of the seat C is supported movably relative to the support base B via the front shaft j2. In addition, the center part of the seat C in the front-rear direction is supported on the support base B via the back support body D that holds the seat engagement shaft j3.

[0036] The center of the seat C in the front-rear direction is supported rotatably about the seat engagement shaft j3. The front of the seat C, which is configured to be rotatable about the seat engagement shaft j3, is configured to be movable in the up-down direction relative to the front shaft j2.

[0037] <Zauke c1> The seat holder c1 has a shell-like shape having a size capable of supporting the seat body c2 at an upper portion. The seat holder c1 is capable of supporting the seat body c2 so as to be slidable in the front-rear direction.

[0038] The seat support c1 comprises a seat support main body 1 which constitutes the main part, an upper spring support member 2 which is configured to be detachable from the seat support main body 1 and has an upper spring support portion 21a, and a retaining portion forming member 3 which is configured to be detachable from the seat support main body 1 and forms part of the seat engagement shaft retaining portion 16 which is the portion which retains the seat engagement shaft j3.

[0039] A front axle arrangement space cs is provided in the front portion of the seat support c1 to allow the front axle j2 to move vertically relative to the seat C. More specifically, a front axle arrangement space cs is provided in the front portion of the seat support c1 to allow the front axle j2, which is disposed at the lower limit position of the front axle support portion b5 of the support base B in the normal posture (M) and fixed at the lower limit position, to be displaced vertically relative to the seat C which rotates around the seat engagement axis j3.

[0040] [Base body 1] The seat support main body 1 comprises a seat support base 11 having a lower support area formed on its upper surface that can be attached to the underside of the support member c21, a front lower extension wall 12 provided in the left-right center of the front part of the underside of the seat support base 11, left and right lower extension walls 13 provided in a pair on the left and right sides of the left and right center of the underside of the seat support base 11 and extending downward from both ends of the front lower extension wall 12 toward the rear, and a rear lower extension wall 14 provided in the left-right center of the rear part of the underside of the seat support base 11 and connecting the rear parts of the left and right lower extension walls 13.

[0041] (Seat base 11) The seat support base 11 has a plurality of exposed ribs extending in the front-rear and left-right directions on the upper surface thereof to ensure rigidity. The upper end of each rib erected on the upper surface of the seat support base 11 forms a lower support area that can be pressed against and slidably contacted with the lower surface of the support member c21 of the seat body c2.

[0042] A front axle abutment portion 15a that can abut against the front axle j2 when the seat C takes a forward tilted position (F) is provided in the front part of the center of the front-rear direction of the seat support base 11 at a position facing the front axle installation space cs. The front axle abutment portion 15a determines the limit position when the seat C tilts forward (the lower limit position of the front part of the seat C when the seat C tilts forward).

[0043] The front shaft abutment portions 15a are formed in a pair on the left and right sides at the lower ends of the protruding portions 15 that protrude downward from the seat base 11. The front shaft abutment portions 15a are recessed in a partial arc shape so as to correspond to the outer circumferential surface of the front shaft j2 in a side view.

[0044] A seat engagement shaft holding portion 16 capable of rotatably holding the seat engagement shaft j3 is provided on the underside of the center portion in the front-rear direction of the seat support base 11. The seat engagement shaft holding portion 16 is provided on the inside of the left and right lower extension walls 13.

[0045] In this embodiment, the seat engagement shaft holding portion 16 is composed of one seat engagement shaft holding portion 16a formed on the seat base 11 and the other seat engagement shaft holding portion 31 formed on a holding portion forming member 3 that is separate from the seat base 11 and attached to the seat base 11.

[0046] In this embodiment, the seat engagement shaft holding portion 16 is formed by cooperating not only with the seat support main body 1 but also with a holding portion forming member 3 which is a member separate from the seat support main body 1. Therefore, compared to a case where the seat engagement shaft holding portion is formed only by an integrally molded product, not only can the work of assembling the seat engagement shaft j3 included in the back support body D to the seat engagement shaft holding portion 16 of the seat support c1 be smoother, but also minute gaps that cause rattling are less likely to occur between the seat engagement shaft j3 and the seat support c1.

[0047] The retaining portion forming member 3 is attached to the seat support base 11 by inserting it into a retaining portion forming member mounting portion 17 having a slit-shaped insertion opening on the upper surface side of the seat support base 11. The work of inserting the retaining portion forming member 3 into the retaining portion forming member mounting portion 17 is performed after provisionally engaging the seat engagement shaft j3 with one of the seat engagement shaft holding portions 16a formed on the seat support main body 1.

[0048] An upper spring receiving member mounting portion 18 is provided at the front of the seat receiving base 11, to which the upper spring receiving member 2 constituting the seat forward tilt mechanism G is attached. The upper spring receiving member mounting portion 18 is formed at a corresponding location on the seat receiving base 11 so that the upper spring receiving member 2 can be disposed on the front axis j2.

[0049] The upper spring receiving member attachment portion 18 is capable of supporting the upper spring receiving member 2 in a state in which it is biased upward by a spring wg that constitutes the seat forward tilting mechanism G.

[0050] The upper spring receiving member mounting portion 18 is equipped with a front retaining portion 18a which can hold the front engagement portion 22 provided on the front part of the upper spring receiving member 2 so that it cannot move upward, and a rear retaining portion 18b which can hold the rear engagement portion 23 provided on the rear part of the upper spring receiving member 2 so that it cannot move upward and cannot move in the front-to-rear direction.

[0051] The rear holding portion 18b is provided with a protrusion engagement hole 18c that penetrates in the vertical direction and into which an engagement protrusion 25 protruding from the rear engagement portion 23 of the upper spring receiving member 2 can be engaged.

[0052] (Left and right lower extension walls 13) The left and right lower extension walls 13 are provided with lower spring receiving member holding portions 13a which are recessed downward and open upward.

[0053] The lower spring receiving member holding portion 13a is recessed to correspond to the shape of the seat engaging portion 42 provided on the lower spring receiving member 4, and is configured to be able to fit into the seat engaging portion 42 in the normal position (M).

[0054] That is, the lower part of the lower spring receiving member holding portion 13a is formed so that the inside dimension in the front-rear direction gradually becomes shorter downward in side view.

[0055] The lower spring receiving member holding portions 13a are disposed on the left and right lower extending walls 13 located outside the left and right side wall portions b3 constituting the support base main body b1.

[0056] The configuration of the lower spring receiving member 4 will be described in detail later.

[0057] [Upper spring support part 2] The upper spring receiving member 2 is configured to be detachable from the seat receiving body 1 without using any fastener. The upper spring receiving members 2 are arranged in a pair on the left and right. The upper spring receiving members 2 are configured to be detachable from upper spring receiving member mounting portions 18 provided in a pair on the left and right of the seat receiving base 11 of the seat receiving body 1.

[0058] The upper spring receiving member 2 comprises a spring receiving member main body 21 arranged in the middle in the fore-and-aft direction and having an upper spring receiving portion 21a on its underside that receives the upper end of the spring wg, a front engagement portion 22 protruding forward from the front end of the spring receiving member main body 21, and a rear engagement portion 23 extending rearward from the rear end of the spring receiving member main body 21 and having an engagement protrusion 25 that protrudes upward at its extended end.

[0059] In this embodiment, the upper spring receiving portion 21a has a substantially smooth surface.

[0060] [Holding part forming member 3] The retaining portion forming members 3 are configured to be detachable from the seat support main body 1 without using any fasteners. The retaining portion forming members 3 are arranged in pairs on the left and right. The retaining portion forming members 3 are configured to be detachable from the retaining portion forming member mounting portions 17 provided in a pair on the left and right of the seat support base 11 of the seat support main body 1.

[0061] The retaining portion forming member 3 is generally L-shaped in side view. The retaining portion forming member 3 includes the other seat engaging shaft retaining portion 31 provided at the rear and having a partially arcuate edge capable of abutting against the outer circumferential surface of the seat engaging shaft j3, and an engaging portion 32 provided at the front and capable of engaging with a retaining engaging portion (not shown) provided on the retaining portion forming member mounting portion 17.

[0062] <Seat body c2> The seat body c2 is supported so as to be slidable in the front-rear direction relative to the seat support c1.

[0063] The seat body c2 includes a shell-shaped support member c21 whose front-to-back and left-to-right dimensions are larger than those of the seat support c1, a seat cushion (not shown) supported by the support member c21 and whose front-to-back and left-to-right dimensions are larger than those of the support member c21, and a seat upholstery c22 that covers the peripheral edges of the seat cushion and support member c21 from the outside.

[0064] <Front axis j2> A front shaft j2 extending in the left-right direction is interposed between the front part of the support base B and the front part of the seat C. As the backrest E tilts backward, the front shaft j2 moves up and down on a front shaft support part b5 in the shape of a long hole that extends at an angle on the left and right side walls b3 of the support base main body b1.

[0065] In this embodiment, a lower spring bearing member 4 that receives a lower end of a spring wg that constitutes the seat forward tilt mechanism G is attached to the front axle j2 so as to be capable of relative rotation. The lower spring bearing member 4 is attached to both the left and right ends of the front axle j2.

[0066] The lower spring bearing member 4 is provided with a front axle retaining hole 43 that penetrates in the left-right direction and into which the front axle j2 is inserted. The lower spring bearing member 4 is provided with a lower spring bearing portion 41 provided at an upper portion and having a portion shaped to engage with the lower end of the spring wg, and a seat engaging portion 42 provided at a lower portion and having the front axle retaining hole 43 in the center in the front-to-rear direction and formed so that the front-to-rear width dimension gradually decreases downward in a side view.

[0067] <<Back support D>> The back support D is interposed between the support base B and the backrest E, and between the support base B and the seat C.

[0068] The back support body D includes a pair of left and right arms d1 each having an upright plate shape extending in the front-to-rear direction and pivoted to the support base main body b1 via a main shaft j1, a connecting member d2 having an upright plate shape connecting the rear portions of the pair of left and right arms d1, a seat engagement shaft j3 extending in the left-right direction and supported at a portion of the pair of left and right arms d1 forward and above the main shaft j1, a pair of left and right bearing shaft support members d3 arranged toward the left-right center side of the pair of left and right arms d1 and whose upper portions are connected to the seat engagement shaft j3, and a bearing shaft d4 connected between the lower portions of the pair of left and right bearing shaft support members d3.

[0069] <Arm d1> The left and right arms d1 are disposed outside the left and right side wall portions b3 of the support base main body b1.

[0070] The left and right arms d1 are provided with left and right arm bodies d11 extending in the front-to-rear direction and capable of supporting the main shaft j1 at their front ends, and left and right front arm portions d12 extending integrally diagonally upward and forward from the front ends of the left and right arm bodies d11 and supporting at their upper ends the seat engagement shaft j3 which engages with the seat C.

[0071] The left and right arm bodies d11 are connected at their rear ends by a connecting member d2. A protruding portion dt is provided at the rear end of the left and right arm bodies d11, protruding rearward from the connecting member d2. The protruding portion dt is adapted to be fitted into a back support member connecting portion (not shown) provided at the lower end of the backrest E.

[0072] <Connection member d2> The left and right ends of the connecting member d2 are rigidly connected to the inner sides of the left and right arm bodies d11 by welding. The connecting member d2 is provided with a nut portion n3 to which a screw (not shown) for attaching the backrest E is screwed.

[0073] The back support D is provided with a backrest attachment portion d5 formed in a substantially H-shape in plan or bottom view by the rear portions of the left and right arm bodies d11 and the connecting member d2.

[0074] <Seat engagement shaft j3> The seat engagement shaft j3 extends in the left-right direction. The seat engagement shaft j3 can move around the support shaft j1, i.e., move upward and rearward, in conjunction with the backward tilting of the backrest E. The seat engagement shaft j3 engages with a seat engagement shaft holder 16 provided in the center of the seat support c1 in the front-rear and left-right directions.

[0075] <Bearing shaft support member d3> The left and right bearing shaft support members d3 are plate-shaped. The left and right bearing shaft support members d3 support the bearing shaft d4 that is pressed by the reaction spring wd. The left and right bearing shaft support members d3 are supported by the main shaft j1 and the seat engagement shaft j3. The left and right bearing shaft support members d3 rigidly connect both ends of the bearing shaft d4 at their lower ends.

[0076] <bearing axis d4> The receiving shaft d4 extends in the left-right direction and is disposed inside the support base main body b1. The receiving shaft d4 directly receives the biasing force of the reaction spring wd disposed inside the support base main body b1.

[0077] <<Backrest E>> The backrest E is connected to the back support D. The entire backrest E can be tilted backward around a main axis j1 provided on the support base B. The backrest E is supported by the back support D so as to be rotatable around the main axis j1 of the support base B.

[0078] The backrest E comprises a back frame e1, a front frame e2 arranged in front of the back frame e1, a tensioning member e3 stretched on the front frame e2, a lumbar support e4 arranged behind the tensioning member e3 and attached to the front frame e2, and a positioning mechanism e5 that enables the front frame e2, which supports the lumbar support e4 and the tensioning member e3, to be repositioned in the front-to-rear direction relative to the back frame e1.

[0079] <Back frame e1> The back frame e1 comprises left and right side frame portions e11 extending in the vertical direction, an upper frame portion e12 connecting the upper ends of the left and right side frame portions e11, left and right lower frame portions e13 extending forward from the lower ends of the left and right side frame portions e11, respectively, and a lower connecting portion e14 connecting the lower ends of the left and right lower frame portions e13.

[0080] The upper surface of the left and right lower frame portions e13 is provided with bearing protrusions e15 each having a shaft hole eh that constitutes a positioning mechanism e5.

[0081] The lower end of the back frame e1, that is, the front end of the left and right lower frame portions e13 and the lower connecting portion e14, are adapted to be attached to the backrest attachment portion d5 of the back support body D.

[0082] <Front back frame e2> The front frame e2 is supported by the back frame e1. The front frame e2 has a continuous frame shape in a front view.

[0083] The front frame e2 can be selectively positioned by the positioning mechanism e5 between a front position (f), a rear position (r) located behind the front position (f), and an intermediate position (m) located halfway between the front position (f) and the rear position (r).

[0084] The front frame e2 comprises left and right side frame portions e21 extending in the vertical direction, an upper frame portion e22 connecting the upper ends of the left and right side frame portions e21, and a lower frame portion e25 connecting the lower ends of the left and right side frame portions e21.

[0085] Axle holders e23 for holding the tip shafts L21 of the left and right links L constituting the positioning mechanism e5 are provided at the lower ends of the left and right side frame portions e21. The axle holders e23 have a C-shaped portion in a side view for holding the tip shafts L21.

[0086] The lower frame portion e24 constituting the left and right side frame portions e21 is formed to be gradually displaced inward as it goes downward. A mounting structure portion PT is provided on the front side of the lower frame portion e24 to mount the mounting portion e42 of the lumbar support e4 without using a fastener.

[0087] The mounting structure portion PT includes inner and outer insertion portions pt1, pt2 for mounting the base portion e45 of the mounting portion e42 in the lumbar support e4, inner and outer clamping walls pt3, pt4 for clamping the front protrusion portion e46 of the mounting portion e42 in the lumbar support e4, and an internal fitting portion pt5 that can be fitted into the recessed portion e47 of the mounting portion e42 in the lumbar support e4.

[0088] A groove-like tool insertion portion pt6 is formed in the left-right middle portion of the inner fitting portion pt5 protruding from the lower frame portion e24, and is configured so that a tool (not shown) can be inserted when removing the mounting portion e42 of the lumbar support e4 from the front frame e2. The tool insertion portion pt6 of the inner fitting portion pt5 is provided, so that the operation of removing the lumbar support e4 from the front frame e2 can be performed smoothly.

[0089] The front frame e2 is configured so that it cannot be detached from the tip shafts L21 of the left and right links L unless it takes a predetermined posture.

[0090] That is, as shown diagrammatically in FIG. 50, the left and right links L are brought into a forward position (F) and the upper frame portion e22 of the front frame e2 is detached from the upper frame portion e12 of the back frame e1, and then the entire front frame e2 is rotated a certain degree around the end axis L21 so as to tilt forward, so that the connection between the axis holding portion e23 of the front frame e2 and the end axis L21 of the link L is not released (the front frame e2 is not detached from the end axis L21).

[0091] <Upholstery member e3> The tension member e3 is a mesh-like fabric that can form the backrest surface, to which a peripheral member made of synthetic resin (not shown) is attached by sewing, etc. The tension member e3 is stretched over the front surface of the front frame e2 by inserting or attaching the end having the peripheral member into or to a mounting groove provided around the front frame e2.

[0092] The tension member e3 is located in front of the lumbar support e4. The tension member e3 has a function of restricting the forward movement of the lumbar support e4 relative to the front frame e2, that is, a function of preventing the lumbar support e4 from slipping out of the front side relative to the front frame e2.

[0093] <Lumbar support e4> The lumbar support e4 is intended to provide focused support for the lumbar area of ​​the seated person from the back side.

[0094] The lumbar support e4 is disposed between the left and right side frame portions e21 of the front frame e2. Both ends of the lumbar support e4 are attached to the left and right lower frame portions e24 constituting the left and right side frame portions e21.

[0095] The lumbar support e4 includes a curved plate-like lumbar support body e41 that receives the load from the user, and mounting parts e42 provided on both ends of the lumbar support body e41. The lumbar support e4 is integrally molded from synthetic resin.

[0096] The lumbar support body e41 includes a main portion e43 located in the left-right middle portion and having a substantially horizontally elongated rectangular shape in a front view, and connecting portions e44 extending obliquely downward and outward from the left and right lower corners of the main portion e43. The connecting portions e44 have attachment portions e42 at their extending ends.

[0097] The mounting portion e42 is configured to be detachably attached to the front portion of the lower frame portion e24 without using any fasteners.

[0098] The mounting portion e42 comprises a plate-shaped base portion e45 extending from the extended end of the connecting portion e44 with approximately the same width dimension, a front protrusion portion e46 protruding forward from the widthwise center of the base portion e45, and a recessed portion e47 recessed in the widthwise center of the rear side of the base portion e45.

[0099] The left and right end portions of the base plate portion e45 are inserted into inner and outer slit-shaped insertion portions pt1, pt2 formed in pairs on the inner and outer sides of the front of the lower frame portion e24. The front protrusion portion e46 is sandwiched between inner and outer sandwiching walls pt3, pt4 that also serve as walls for forming the inner and outer insertion portions pt1, pt2 provided on the lower frame portion e24. The recessed portion e47 is fitted externally into the inner fitting portion pt5 protruding from the lower frame portion e24.

[0100] The lumbar support e4 is attached from the back side to the front frame e2 in a state in which the tension member e3 is tensioned. That is, the attachment portion e42 of the lumbar support e4 is lowered while being pressed against the back side of the tension member e3 from the rear side of the backrest E, inserted between the tension member e3 and the lower frame portion e24, and engaged with the attachment structure portion PT provided on the lower frame portion e24, thereby attaching the lumbar support e4 to the front frame e2.

[0101] On the other hand, when removing the lumbar support e4 from the front frame e2, the work can be smoothly performed by inserting the tip of a tool (e.g., a flat-head screwdriver) into the groove-shaped tool insertion portion pt6 provided in the internal fitting portion pt5 formed in the lower frame portion e24 of the front frame e2.

[0102] <Positioning mechanism e5> The positioning mechanism e5 can selectively position the lower end of the front frame e2 to a front position (not shown), a middle position (not shown), or a rear position (r) by changing the posture of the left and right links L.

[0103] The positioning mechanism e5 is provided between the left and right lower frame portions e13 of the back frame e1 and the lower end portion of the front frame e2.

[0104] The positioning mechanism e5 comprises left and right links L which have at their base ends a base end shaft L11 which is axially supported by the bearing protrusion e15 of the back frame e1 and at their tip ends a tip shaft L21 which is held by the shaft holding portion e23 of the front frame e2 and which are rotatably connected to the back frame e1 and the front frame e2; a link operating lever L3 which is arranged on the outside of the left and right links L and which can be rotated so as to change the position of the left and right links L to a front position (F), a middle position (M), and a rear position (R); and a rotation restriction mechanism P which is provided between the link operating lever L3 and the bearing protrusion e15 and which restricts the relative rotation of the left and right links L with respect to the bearing protrusion e15 when the link operating lever L3 is not operated.

[0105] [Left and right links L] The left and right links L can rotate between a front position (F) inclined forward and a rear position (R) inclined backward. In this embodiment, the left and right links L can be maintained in three positions with respect to the bearing protrusion e15 by the rotation restriction mechanism P, namely, the front position (F) shown in Figures 49 and 50, the rear position (R) shown in Figures 1, 3 to 5, 7, and 45 to 47, and an intermediate position (M) between the front position (F) and the rear position (R) shown in Figure 48.

[0106] The left and right links L can rotate in the front-rear direction about the base end shaft L11 when an operating force is applied to the link operating lever L3 to rotate the left and right links L about the base end shaft L11. The left and right links L are mainly composed of an inner link member L1 and an outer link member L2.

[0107] The base end of the inner link member L1 is provided with a base end shaft L11 that is inserted into the shaft hole eh of the bearing projection e15. The tip end of the inner link member L1 is provided with a fitting hole L12 into which the protruding end of the tip shaft L21 that protrudes from the tip end of the outer link member L2 can be fitted. The middle position of the inner link member L1 is provided with a screw insertion hole h4 through which a screw v4 is inserted to connect the inner link member L1 and the outer link member L2.

[0108] An arrangement space L22 is formed on the inside of the base end of the outer link member L2, in which the engagement member p2, coil spring wp, and shaft member p3 constituting the rotation restricting mechanism P are arranged. A cylindrical portion L23 that is open to the outside and whose axis coincides with the base end axis L11 is protruded from the outside of the base end of the outer link member L2. A lever base end L31 of the link operating lever L3 is attached to the cylindrical portion L23 so as to be movable in the axial direction.

[0109] A tip shaft L21 held by a shaft holder e23 is provided at the tip of the outer link member L2. The protruding end of the tip shaft L21 is adapted to fit into a fitting hole L12 provided in the inner link member L1. A nut portion n4 is provided at the middle position of the outer link member L2, into which a screw v4 passing through a screw insertion hole h4 of the inner link member L1 is screwed.

[0110] [Link control lever L3] The link operating lever L3 extends in the left-right direction and has a nut portion n5 on its inner side to which the shaft member p3 constituting the rotation restricting mechanism P can be screwed, and is equipped with a lever base end L31 having an engagement portion disposed near the nut portion n5 and capable of engaging with a protrusion L24 protruding from the inner surface of the cylindrical portion L23, and an operating piece L32 extending in a direction intersecting the lever base end L31.

[0111] The lever base end L31 is configured to be movable in the axial direction relative to the cylindrical portion L23 provided on the left and right links L. On the other hand, the link operating lever L3 is configured to rotate the link L around the base end axis L11 by engaging the engagement portion L33 of the lever base end L31 with the protrusion L24 provided on the inner circumferential surface of the cylindrical portion L23 of the outer link member L2.

[0112] [Rotation restriction mechanism P] The rotation restriction mechanism P is provided between the link operating lever L3 and the bearing protrusion e15, and is capable of restricting relative rotation of the left and right links L with respect to the bearing protrusion e15 when the link operating lever L3 is not being operated, and at the same time, allowing rotation of the link L with respect to the bearing protrusion e15 when the user rotates the link operating lever L3.

[0113] The rotation restricting mechanism P includes an annular engagement portion p1 having an engagement recess p11 recessed into the outer surface side of the bearing protrusion e15 and surrounding the periphery of the shaft hole eh and open toward the shaft hole eh at a fixed interval, an engagement member p2 having a mountain-shaped protrusion p21 provided on its outer peripheral edge and engaging with the engagement recess p11 at a fixed interval, a coil spring wp disposed between the end face of the engagement member p2 on the side opposite the bearing protrusion and a scaffolding wall L25 provided at a location facing the arrangement space L22 of the outer link member L2, and biasing the engagement member p2 toward the bearing protrusion e15, and an axis member p3 capable of supporting the engagement member p2 so as to be movable in the axial direction relative to the link operating lever L3.

[0114] When the user is not rotating the link operating lever L3, the coil spring wp urges the engagement member p2 toward the annular engagement portion p1, so that the left and right links L do not rotate even when subjected to an external force from the front frame e2.

[0115] Because the rotation restriction mechanism P is in effect, the positioning mechanism e5 will not move in the forward position (F) or rearward position (R) direction unless the link operating lever L3 is operated, even if an external force is applied from the front frame e2 when the left and right links L are in the intermediate position (M).

[0116] On the other hand, when the user rotates the link operating lever L3, the rotation restriction mechanism P causes the engagement between the annular engagement portion p1 and the engagement member p2 to temporarily move in a direction away from the annular engagement portion p1 against the biasing force of the coil spring wp, thereby allowing the link L to be rotated to a predetermined position.

[0117] <<Armrest K>> The armrests K are provided in pairs on the left and right sides of the chair body. The lower ends of the armrests K are attached to the underside of the seat C that constitutes the chair body, more specifically, to the underside of the seat support c1.

[0118] The armrest K comprises an armrest base KB including an arm support 5 attached to the chair body and an armrest support part 6 supported by the arm support 5, and an armrest 7 movable in the forward / backward direction relative to the armrest base KB.

[0119] The armrest K comprises an arm support 5 attached to the chair body, and an armrest body KH which includes an armrest 7 and an armrest support part 6 and is supported on the arm support 5 so that its vertical position can be changed.

[0120] The armrest body KH is mainly composed of an armrest support part 6 which is held so as to be movable up and down relative to the arm support 5, and an armrest 7 which is arranged so as to be slidable in the front-rear direction relative to the armrest support part 6.

[0121] In this embodiment, the armrest K is provided with an armrest guide mechanism Q between the armrest base KB and the armrest 7, which guides the armrest 7 so that it can move in the forward and backward directions, and a lifting mechanism T is provided which can raise and lower the armrest main body KH in the vertical direction relative to the arm support 5 and can be locked at a predetermined height position.

[0122] Hereinafter, each configuration of the armrest K of this embodiment will be described in detail.

[0123] <Elbow Support 5> The armrest support 5 has a connection part 511 at its base end that connects to the seat support c1 of the seat C that constitutes the chair body. The connection part 511 is fixed to the seat support c1 with a screw. The armrest support 5 is interposed between the armrest body KH and the chair body.

[0124] The elbow support 5 is substantially L-shaped when viewed from the front and rear. The lower part of the elbow support 5 extends in the left-right direction, and the upper part of the elbow support 5 extends in the up-down direction. The upper part of the elbow support 5 is shaped to be able to hold the armrest main body KH so that it can move in the up-down direction, that is, it is tubular and open at the top.

[0125] The elbow support 5 comprises an elbow support body 51 which is an integrally molded product, and an interior member 52 disposed inside the elbow support body 51.

[0126] [Elbow support body 51] The elbow support main body 51 has a connection portion 511 at the lower portion i3 extending in the left-right direction that is screwed to the underside of the seat support c1, and has a cylindrical portion 512 at the upper portion extending in the vertical direction that is open upward.

[0127] [Interior materials 52] The interior member 52 is disposed so as to fit along the inner circumferential surface of the cylindrical portion 512. The interior member 52 is inserted into the cylindrical portion 512, and attached to the elbow support body 51 by a screw v1.

[0128] At the rear of the interior member 52, a plurality of engaged parts 521 constituting the lifting mechanism T are arranged in parallel at regular intervals in the up-down direction. The engaged parts 521 are formed of holes penetrating in the front-rear direction. The engaged parts 521 are adapted to be engaged with the protrusions 92 of the engaging members 9 constituting the lifting mechanism T.

[0129] Guide rails 522 extending in the vertical direction are provided to protrude from the front and rear of the inner circumferential surface of interior member 52. Guide rails 522 are adapted to engage with guide recesses 611 recessed into the front and rear of the outer circumferential surface of cylindrical portion 61 of elbow rest support part 6 so as to extend in the vertical direction.

[0130] <Elbow support part 6> The elbow rest support part 6 is supported on the elbow support 5 so as to be movable up and down.

[0131] The elbow rest support part 6 comprises a cylindrical part 61 which is arranged within the cylindrical part 512 of the elbow support main body 51 and extends in the vertical direction so as to be able to move up and down relative to the cylindrical part 512, and a support base part 62 which is connected to the top of the cylindrical part 61 and has a first guide slit S1 and a fixed guide shaft j4 on its upper surface part 62b which constitute the elbow rest guide mechanism Q.

[0132] The elbow rest support portion 6 is formed with a lower wire member arrangement space 63 in which the wire member wy can be arranged.

[0133] [Cylindrical part 61] The cylindrical portion 61 has an internal space formed therein in which an engagement unit TU constituting the lifting mechanism T can be disposed and in which a wire member wy can be housed.

[0134] The cylindrical portion 61 has a guide recess 611 recessed so as to extend vertically from front to back on the outer circumferential surface, and a window hole portion 612 penetrating in the front to back direction at the rear of the lower portion, in which an engaging member 9 constituting the lifting mechanism T is arranged so as to be able to move forward and backward.

[0135] The cylindrical portion 61 has a protrusion engagement hole (not shown) on the front side of the lower part into which the tip protrusion 87 of the engagement arm provided on the unit base 8 engages, and an engagement recess 614 at the lower end into which a protrusion formed on the unit base 8 engages.

[0136] [Support base part 62] The support base portion 62 is formed to have a dimension in the front-rear direction larger than that of the cylindrical portion 61. The rear portion of the support base portion 62 extends rearward beyond the cylindrical portion 61 in a cantilever shape.

[0137] The support base portion 62 has a peripheral wall portion 62a that is connected to the cylindrical portion 61 and is formed so that the front-to-rear dimension gradually becomes longer toward the top when viewed from the side, and an upper surface portion 62b that is provided so as to partially cover an open portion formed at the upper end of the peripheral wall portion 62a.

[0138] Inside the peripheral wall portion 62a, first and second upper surface portion constituent members 64, 65 which constitute the upper surface portion 62b, and nuts n2, n6 for mounting the fixed guide shaft j4 are disposed.

[0139] The upper surface portion 62b is capable of supporting the elbow rest 7 from below so as to be slidable in the front-rear direction. In other words, the upper surface portion 62b functions as a base for the elbow rest 7 which is movable in the front-rear direction.

[0140] The upper surface portion 62b is provided with a first guide slit S1 that can guide the elbow rest 7 along a predetermined trajectory by engaging with a downwardly protruding movable guide shaft j5 provided on the elbow rest 7, a fixed guide shaft j4 that is located behind the first guide slit S1 and protrudes upward, and a lower wire member communication hole 652 that is located between the first guide slit S1 and the fixed guide shaft j4, penetrates in the vertical direction, and allows a part of the wire member wy to pass through.

[0141] The upper surface portion 62b is composed of a first upper surface portion component 64 having an inner plate portion 641 and an outer plate portion 642 surrounding the inner plate portion 641, and a first guide slit S1 forming a ring shape formed between the inner plate portion 641 and the outer plate portion 642, and a second upper surface portion component 65 having a cover portion 651 at the front portion covering the top of the outer plate portion 642 of the first upper surface portion component 64, and in which a wire member communication hole 652 and a shaft insertion hole 653 are formed below the cover portion 651.

[0142] The shaft insertion hole 653 of the second top surface component 65 is provided for attaching the fixed guide shaft j4 to a nut portion n2 provided inside the peripheral wall portion 62a.

[0143] The first upper surface portion constituent member 64 and the second upper surface portion constituent member 65 are connected so as to partially overlap in the vertical direction by engaging a claw portion 654 provided on the second upper surface portion constituent member 65 with a claw engagement portion 643 provided on the first upper surface portion constituent member 64. These connected first and second upper surface portion constituent members 64, 65 are attached to the upper end portion of the peripheral wall portion 62a by screwing a screw v2 inserted through a screw insertion hole h2 provided in the first upper surface portion constituent member 64 into a nut portion n2 provided in the peripheral wall portion 62a.

[0144] The first guide slit S1 is adapted to engage with a movable guide shaft j5 provided on the armrest 7. The configuration of the first guide slit S1 will be described in detail later.

[0145] The fixed guide shaft j4 is adapted to engage with a second guide slit S2 provided on the armrest 7. The fixed guide shaft j4 is equipped with a shaft body j41 having a head, and a ring-shaped spacer member j42 made of synthetic resin attached to the shaft body j41.

[0146] The lower wire member communication hole 652 is formed in a rectangular shape elongated in the left-right direction. The lower wire member communication hole 652 is provided so as to extend over substantially the entire area in the width direction of the upper surface portion 62b.

[0147] [Lower wire component arrangement space 63] The lower wire member arrangement space 63 is provided inside the elbow rest support part 6, i.e., inside the cylindrical part 61 and the support base part 62. The lower wire member arrangement space 63 is configured so that a part of the wire member wy can be arranged therein.

[0148] <Elbow pad 7> The armrest 7 is provided on the upper surface of which the arm of a seated person is placed. The armrest 7 extends in the front-rear direction as a whole. The armrest 7 includes an armrest base 71 and an armrest pad 72 disposed on the armrest base 71.

[0149] Inside the elbow rest 7, i.e., between the elbow rest base 71 and the elbow rest pad 72, there is provided an upper wire member arrangement space sp, which is an arrangement space in which a part of the wire member wy can be arranged. The elbow rest 7 in this embodiment is provided with an operating lever R for operating the armrest body KH so that it can be raised and lowered relative to the elbow support 5.

[0150] [Elbow Rest Base 71] The armrest base 71 is made of synthetic resin and has a shape that extends in the front-rear direction as a whole. An operating lever R that constitutes a lifting mechanism T for raising and lowering the armrest body KH is rotatably supported on the armrest base 71.

[0151] The elbow rest base 71 comprises a bottom wall portion 711 having a substantially flat bottom surface which can slide against the upper surface 62b of the elbow rest support portion 6, and a peripheral wall portion 712 which stands upright from the outer periphery of the bottom wall portion 711.

[0152] The bottom wall portion 711 is provided with a shaft support portion 713 arranged at the front of the upper surface side and capable of rotatably supporting the left and right shaft portions r11 protruding from the operating lever R, a second guide slit S2 arranged rearward of the shaft support portion 713 and penetrating in the vertical direction, a claw receiving portion 714 with which an engaging claw 725 provided on the elbow pad 72 can engage, and a nut portion n1 to which a movable guide shaft j5 is attached, which is arranged in front of the second guide slit S2 and protrudes downward beyond the bottom surface portion.

[0153] A window hole 715 is provided in the front part of the peripheral wall 712, penetrating in the front-rear direction to allow the operating part r2 of the operating lever R, on which the user's fingers are placed, to protrude forward. In addition, a protrusion engagement part 716 is provided above the window hole 715 in the front part of the peripheral wall 712, with which an engagement protrusion 726 provided on the elbow pad 72 can engage.

[0154] The second guide slit S2 constitutes the elbow rest guide mechanism Q. The second guide slit S2 is adapted to engage with a fixed guide shaft j4 that protrudes from the support base portion 62 of the elbow rest support portion 6.

[0155] The second guide slit S2 is curved inward in plan view, i.e., convex toward the center of the chair body in the left-right direction. The front end of the second guide slit S2 is provided with a front end region SE that is set so that the fixed guide shaft j4 is not positioned therein even when the armrest 7 is in the most rearward position (R). The front end region SE is a location through which the wire member wy can pass when the armrest 7 is in the most rearward position (R).

[0156] An upper wire member communication hole that penetrates vertically and allows a portion of the wire member wy to pass through is formed in the elbow rest base 71. The wire member communication hole in this embodiment also serves as the second guide slit S2 that penetrates vertically.

[0157] The movable guide shaft j5 is adapted to engage with the first guide slit S1 provided on the elbow rest support section 6 side. The movable guide shaft j5 is provided in front of the second guide slit S2. The movable guide shaft j5 is attached to a nut section n1 provided on the elbow rest base 71. The movable guide shaft j5 is provided in the center in the left-right direction in a plan view so as to protrude downward from the lower surface of the bottom wall section 711. The movable guide shaft j5 comprises a shaft body j51 having a head, and a ring-shaped synthetic resin spacer member j52 attached to the shaft body j51.

[0158] [Elbow pad 72] The elbow pad 72 has an upper surface on which the arm of a seated person is placed. The elbow pad 72 includes a pad main body 721 having cushioning properties arranged on the upper part, and a body receiving member 722 made of synthetic resin attached below the pad main body 721. In this embodiment, the pad main body 721 and the body receiving member 722 are integrally formed by insert molding.

[0159] The main body receiving member 722 is provided with a plate-shaped receiving member main body 723 attached to the underside of the pad main body 721, an elastic biasing portion 724 arranged on the underside of the receiving member main body 723 and engaging with the operating lever R supported by the elbow rest base 71 to bias the operating lever R in the direction of the initial position (D), and an engaging claw 725 and an engaging protrusion 726 that engage with the claw receiving portion 714 and protrusion engaging portion 716 of the elbow rest base 71.

[0160] The elastic biasing portion 724 includes left and right support protrusions 727 that protrude downward from the receiving member main body 723 , and a flexible portion 728 that is shaped like a corrugated plate and is disposed between the left and right support protrusions 727 .

[0161] The elastic biasing portion 724 utilizes elastic deformation of a flexible portion 728 mounted on left and right support protrusions 727 to press an engaging protrusion r12 provided on a base end portion r1 of the operating lever R forward.

[0162] The flexible portion 728 presses the engaging protrusion r12 forward, so that the operating lever R can take the initial position (D), that is, the initial position (D) in which the operating portion r2 of the operating lever R is tilted forward.

[0163] The engagement unit TU constituting the lifting mechanism T is provided with a spring wt for biasing the engagement member 9 toward the engagement position (F). Therefore, the operating lever R connected to the engagement member 9 via the wire member wy is configured to be able to return to the initial position (D) by the biasing force of the spring wt pressing the engagement member 9, even in the absence of the elastic biasing portion 724 of the armrest 7.

[0164] In other words, the elastic biasing portion 724 in this embodiment provides an auxiliary biasing force for returning the operating lever R to the initial position (D), taking into account minute dimensional differences that may occur in the wire member wy from product to product.

[0165] [Operation lever R] The operating lever R is for operating the armrest body KH so that the position can be changed up and down. The operating lever R is rotatably supported on the armrest 7 which can slide forward and backward. The operating lever R is disposed at the front end of the armrest 7.

[0166] The operating lever R is configured to be capable of changing its position between an initial position (D) in which it is not receiving operating force from the user, and an operating position (not shown) which is a position different from the initial position (D) when it receives operating force from the user.

[0167] The operating lever R includes a base end r1 having a shaft portion that is a rotation axis, and an operating portion r2 that extends forward from the base end r1 and receives an operating force from the user's fingers.

[0168] The base end r1 is provided with left and right shaft portions r11 which are protruded in the left-right direction with their axes aligned, an engaging protrusion r12 which is protruded between the left and right shaft portions r11 so as to be positioned above the axes of the left and right shaft portions r11 and which forms a portion which is pressed forward by the elastically biasing portion 724, and a wire connecting portion r13 which is protruded so as to be positioned below the axes of the left and right shaft portions r11 and to which one end of the wire member wy is connected.

[0169] The operating portion r2 is plate-shaped and protrudes forward through a window hole 715 in the elbow rest base 71.

[0170] <<Elbow support guide mechanism Q>> The elbow rest guide mechanism Q is configured to allow the elbow rest 7 to slide on one of multiple, i.e. two, elbow rest trajectories, an outer elbow rest trajectory SW and an inner elbow rest trajectory UW, between the most forward position (F) and the most rearward position (R).

[0171] The elbow rest guide mechanism Q is provided between the elbow rest support part 6 and the elbow rest 7 which constitute the armrest base part KB.

[0172] The elbow rest guide mechanism Q includes a first guide slit S1 and a fixed guide shaft j4 provided on the armrest base KB side, a second guide slit S2 provided on the elbow rest 7 side and engaging with the fixed guide shaft j4, and a movable guide shaft j5 which engages with the first guide slit S1.

[0173] The elbow rest guide mechanism Q has two slit portions, an outer slit portion QS and an inner slit portion QU, which connect the first guide slit S1 between one slit end Sf corresponding to the most forward position (F) and the other slit end Sr corresponding to the most backward position (R).

[0174] The outer slit portion QS is disposed outside the inner slit portion QU. The inner slit portion QU is disposed inside the outer slit portion QS. The outer slit portion QS and the inner slit portion QU are provided only in the first guide slit S1 that is provided in an annular shape in a plan view.

[0175] The elbow rest guide mechanism Q is configured to be able to select between an outer elbow rest trajectory SW, in which the movable guide shaft j5 engages with the outer slit portion QS to move the elbow rest 7 forward and backward, and an inner elbow rest trajectory UW, in which the movable guide shaft j5 engages with the inner slit portion QU to move the elbow rest 7 forward and backward.

[0176] <<Explanation of operation of elbow rest guide mechanism Q>> The armrest 7 is capable of sliding forward and backward relative to the armrest support part 6. The armrest 7 is capable of moving forward and backward on two armrest trajectories (2-way trajectories), namely, an outer armrest trajectory SW and an inner armrest trajectory UW, between a most rearward position (R) in which the armrest is positioned forward and facing approximately parallel to the center line of the chair body in the left-right direction, and a most forward position (F) in which the armrest is positioned more inward than the most rearward position (R).

[0177] <Outside elbow rest trajectory SW> The outer elbow rest trajectory SW in the elbow rest 7 is realized by cooperation between the outer slit portion QS of the first guide slit S1, which is a fixed slit provided in the elbow rest support part 6, and the movable guide shaft j5 provided in the elbow rest 7, and by cooperation between the second guide slit S2, which is a movable slit provided in the elbow rest 7, and the fixed guide shaft j4 provided in the elbow rest support part 6.

[0178] The outer slit portion QS used in the outer elbow rest track SW is set in a mountain shape that is gently convex outward.

[0179] The elbow rest guide mechanism Q is configured so that when the movable guide shaft j5 is engaged with the outer slit portion QS connecting one and the other slit end portions Sf, Sr and the elbow rest 7 is slid in the forward / backward direction, the degree of left / right swivel at the front of the elbow rest 7 is gentler compared to the inner elbow rest trajectory UW.

[0180] <Inner slit part QU> The inner elbow rest trajectory UW in the elbow rest 7 is realized by cooperation between the inner slit portion QU of the first guide slit S1, which is a fixed slit provided in the elbow rest support part 6, and the movable guide shaft j5 provided in the elbow rest 7, and cooperation between the second guide slit S2, which is a movable slit provided in the elbow rest 7, and the fixed guide shaft j4 provided in the elbow rest support part 6.

[0181] The inner slit portion QU used in the inner elbow rest trajectory UW is set to have a mountain shape so as to be convex inward. The degree of inward protrusion of the inner slit portion QU is greater than the degree of outward protrusion of the outer slit portion QS.

[0182] For this reason, the elbow rest guide mechanism Q is configured so that when the movable guide shaft j5 is engaged with the inner slit portion QU connecting one and the other slit end portion Sf, Sr and the elbow rest 7 is slid in the front-to-back direction, the degree of left-to-right swivel at the front of the elbow rest 7 is greater compared to the outer elbow rest trajectory SW.

[0183] The armrest guide mechanism Q is set so that when the movable guide axis j5 is positioned at the intermediate position QM in the inner slit portion QU, which is closest to the left-right center of the chair body, the armrest 7 assumes an inward posture (M) in which the front end is positioned most inward relative to the rear end.

[0184] <<Lifting mechanism T>> The lifting mechanism T allows the vertical position of the armrest body KH relative to the arm support 5 to be determined by operating an operating lever R provided on the armrest 7 which is configured to be slidable in the forward and backward directions.

[0185] The lifting mechanism T is composed of an operating lever R provided on the elbow rest 7, an engaged part 521 provided alongside the elbow support 5, an engaging member 9 arranged on the elbow rest support part 6 and capable of moving back and forth between an engaging position (F) where it can engage with the engaged part 521 in conjunction with a rotational operation of the operating lever R and a retracted position (not shown) where it does not engage with the engaged part 521, and a wire member wy connecting the operating lever R and the engaging member 9.

[0186] In this embodiment, the engaging member 9 constitutes an engaging unit TU in which a plurality of parts are assembled so as to be integrally handleable.

[0187] <Right control lever> The structure of the operating lever R has already been described above and will not be described here.

[0188] The operating lever R is configured to be capable of changing its position between an initial position (D) in which the plate-shaped operating part r2 is tilted forward, and an operating position (not shown) in which the operating part r2 rotates around the left and right shaft parts r11 in response to an operating force from the user, and the front end of the operating part r2 moves upward from the initial position (D).

[0189] <Engaged portion 521> The engaged portion 521 can engage with the engaging member 9 arranged on the elbow rest support portion 6. In this embodiment, the engaged portion 521 is in the form of a window hole penetrating in the front-to-rear direction. A plurality of the engaged portions 521 are arranged side by side at regular intervals in the up-down direction at the rear of the interior member 52 constituting the elbow support 5.

[0190] <Engagement unit TU> The engagement unit TU, which includes the engagement member 9, is attached to the lower part of the cylindrical portion 61 of the elbow rest support part 6.

[0191] The engagement unit TU comprises a unit base 8 attached to the elbow rest support portion 6, an engagement member 9 arranged so as to be movable forward and backward relative to the unit base 8 between an engagement position (F) at which it can engage with the engaged portion 521 of the elbow support 5 and a retracted position retracted from the engagement position (F), and a spring wt arranged between the unit base 8 and the engagement member 9 for urging the engagement member 9 towards the engagement position (F).

[0192] [Unit Base 8] The unit base 8 is mainly composed of a block-shaped portion that is sized so that it can be attached to the cylindrical portion 61 of the elbow rest support portion 6.

[0193] The unit base 8 is equipped with an engaging member holding portion 81 which has a storage space capable of accommodating the engaging member 9 so that it can be moved forward and backward, and which has a portion which can hold the engaging member 9 so that it can be protruded and retracted in the front-to-rear direction, an engaging arm portion 82 which extends from the lower end at the front part in the shape of an elastically deformable arm and has a tip protrusion 87 at its extended end which can engage with a protrusion engaging hole (not shown) provided in the elbow rest support portion 6, an engaging protrusion portion 83 which protrudes outward from the lower end and can engage with an engaging recess 614 provided in the elbow rest support portion 6, and a bending guide portion 84 which bends the wire member wy which extends in the vertical direction in the direction extending in the front-to-rear direction.

[0194] The engaging member holding portion 81 has a groove portion 85 in the top wall portion and bottom wall portion facing the storage space, with which the convex rail portion 911 of the engaging member 9 can engage, and a front spring holding portion 86 in the front wall portion facing the storage space, with which the front end portion of the spring wt can be held.

[0195] [Engagement member 9] The engaging member 9 includes a base portion 91 and a protruding portion 92 that protrudes rearward from the base portion 91 and is an engaging end that can engage with the engaged portion 521 .

[0196] The base 91 is equipped with convex rail portions 911 arranged at the top and bottom and extending in the front-to-rear direction so as to engage with the concave groove portion 85 of the engaging member holding portion 81, a rear spring holding portion 912 provided at the front and capable of holding the rear end portion of the spring wt, and a wire connecting portion 913 arranged adjacent to the rear spring holding portion 912 and connecting to the wire member wy.

[0197] <Wire material wy> The wire member wy connects the operating lever R and the engagement member 9. The wire member wy transmits to the engagement member 9 the operating force applied to the operating lever R by the user.

[0198] The engaging member 9 connected to the wire member wy is biased toward the engaging position (F) by the spring wt. Therefore, the operating lever R connected to the engaging member 9 via the wire member wy can take the initial position (D) when the user is not operating the operating lever R.

[0199] One end of the wire member wy is connected to the wire connection portion r13 of the operating lever R arranged on the elbow rest 7, and the other end is connected to the wire connection portion 913 of the engagement member 9 arranged in the cylindrical portion 61 of the elbow rest support portion 6.

[0200] <About the location of the wire material wy> The wire member wy passes through an upper wire member arrangement space sp provided inside the elbow rest 7, i.e. between the elbow rest base 71 and the elbow rest pad 72, a second guide slit S2 which also serves as an upper wire member communication hole provided in the elbow rest base 71, a lower wire member communication hole 652 provided in the top surface portion 62b of the elbow rest support part 6, and the lower wire member arrangement space 63 which is the hollow internal space of the elbow rest support part 6, to connect the operating lever R and the engaging member 9.

[0201] <<Operation explanation of lift mechanism T>> The lifting mechanism T determines the vertical position of the armrest main body KH relative to the elbow support 5 by selectively engaging an engaging member 9 arranged on the elbow rest support portion 6 with one of a plurality of engaging portions 521 arranged on the elbow support 5.

[0202] The lifting mechanism T in this embodiment is provided on the armrest 7, which allows the operating lever R to slide in the front-rear direction. Therefore, the lifting mechanism T transmits the operating force of the operating lever R to the engagement member 9 using the wire member wy, so that the armrest body KH can be moved up and down by operating the operating lever R at any point within the movable range of the armrest 7 in the front-rear direction.

[0203] The path between the operating lever R, on which the wire member wy is arranged, and the engagement member 9 is the longest when the armrest 7 is in the most forward position (F). On the other hand, when the armrest 7 is in the most rearward position (R), the path between the operating lever R, on which the wire member wy is arranged, and the engagement member 9 is the shortest.

[0204] Therefore, in this embodiment, an upper wire member arrangement space sp is provided inside the elbow rest 7, in which the wire member wy is configured to be capable of flexural and bending deformation, at least when the elbow rest 7 is in the most rearward position (R).

[0205] Additionally, a lower wire member communication hole 652 extending in the left-right direction is provided on the top surface 62b of the elbow rest support part 6. For this reason, even if the wire member wy is forcibly moved left-right by the curved second guide slit S2 as the elbow rest 7 slides forwards and backwards, the lower wire member communication hole 652 can smoothly guide the wire member wy into the elbow rest support part 6.

[0206] <<Headrest I>> The headrest I comprises a headrest main body IH having a support surface for supporting the head of a seated occupant, a base IK supporting the headrest main body IH so that it can rotate in the front-to-rear direction, a frame mounting part IF attached to the upper frame part e12 of the back frame e1 and supporting the base IK, and a vertical position change mechanism IC provided between the frame mounting part IF and the base IK for sliding the base IK in the vertical direction relative to the frame mounting part IF so that its position can be changed.

[0207] <Headrest body induction> The headrest main body IH has a roughly rectangular frame shape when viewed from the front and the back, and comprises a frame portion i1 having mounting grooves on its peripheral edge for attaching a tensioning member, and a tensioning member i2 that forms a head support surface stretched against the frame portion i1.

[0208] A shaft holding portion i11 is provided at the lower portion of the frame portion i1 to hold a shaft portion i42 protruding from the base portion IK.

[0209] <Base IK> The base IK comprises a lower portion i3 having a lower plate-shaped portion i31 extending in the vertical direction, and an upper portion i4 having an upper plate-shaped portion i41 extending forward from the upper end of the lower portion i3 and having an axis portion i42 at its tip which is held by an axis holding portion i11 disposed on the frame portion i1.

[0210] [Lower part i3] The lower portion i3 includes a lower plate-shaped portion i31 which is formed so that its left-right width dimension gradually decreases going downward, guide rails i32 which constitute the vertical position change mechanism IC and are formed on the front side of the lower plate-shaped portion i31 and extend in the vertical direction in a pair on the left and right, and an engagement member holding portion i33 which constitutes the vertical position change mechanism IC and is formed in the vertical center between the left and right guide rails i32 on the front side of the lower plate-shaped portion i31 and holds an engagement member i7 which can engage with the frame mounting portion IF so that it can be protruded and retracted in the front-rear direction.

[0211] The left and right guide rails i32 each have a base end ik extending forward from the lower plate-like portion i31 and a tip end is protruding outward from the extending end of the base end ik. The left and right guide rails i32 are engaged with left and right rail receiving portions i52 provided on the rear side of the frame attachment portion IF, thereby restricting movement in the front-rear and left-right directions and allowing movement in the up-down direction.

[0212] The engaging member holding portion i33 holds the engaging member i7 constituting the vertical position change mechanism IC and the spring wi which biases the engaging member i7 forward. The engaging member holding portion i33 includes a frame-shaped portion iw which protrudes forward from the lower plate-shaped portion i31 to form a substantially rectangular tube, a guide protrusion it which protrudes from the inside of the frame-shaped portion iw and engages with the guide groove ig of the engaging member i7, and a rear spring holding portion id which protrudes forward from the lower plate-shaped portion i31 located within the frame-shaped portion iw and holds the rear end of the spring wi.

[0213] <Frame mounting part IF> The frame mounting portion IF comprises a base member i5 having an upper engagement portion i51 on the front side of the upper portion that engages with the upper portion of the upper frame portion e12 of the back frame e1, left and right rail receiving portions i52 extending in the vertical direction on the back side, and an engaged portion i53 provided between the left and right rail receiving portions i52 and having a plurality of engaging recesses i a arranged in the vertical direction with which an engaging member i7 can engage, and a lower mounting member i6 that is attached to the base member i5 with screws not shown, and has a lower engagement portion i61 that engages with the lower portion of the upper frame portion e12 of the back frame e1.

[0214] The frame attachment portion IF is supported by the back frame e1 by sandwiching the upper frame portion e12 of the back frame e1 between the upper engagement portion i51 and the lower engagement portion i61.

[0215] The left and right rail receiving portions i52 each have a groove portion im that extends in the vertical direction and is open inward. The tip end of the guide rail i32 can be engaged with the groove portion im.

[0216] The engaged portion i53 has a plurality of engaging recesses ia arranged vertically to be engaged with the engaging member i7 having a mountain-shaped tip. The engaging recesses ia are composed of an upper recess-forming surface ix that slopes upward so as to be positioned gradually rearward, and a lower recess-forming surface iz that slopes downward so as to be positioned gradually rearward. The inclination of the lower recess-forming surface iz with respect to a vertical imaginary line corresponding to the vertical movement direction of the base IK is set to be greater than the inclination of the upper recess-forming surface ix.

[0217] <Up / Down position change mechanism IC> The vertical position changing mechanism IC is configured to change the position of the base IK and the headrest main body IH supported by the base IK in the vertical direction relative to the frame attachment part IF.

[0218] The up-down position change mechanism IC is mainly composed of a guide rail i32 and an engaging member holding portion i33 provided on the base IK, an engaging member i7 held by the engaging member holding portion i33 and a spring wi that biases the engaging member i7, and left and right rail receiving portions i52 and engaged portions i53 provided on the frame mounting portion IF.

[0219] The engaging member i7 has a block-like appearance as a whole. The engaging member i7 is provided with a tip engaging portion having an upper inclined surface ib at a tip portion thereof set at an inclination degree that allows the engaging portion to be planarly engaged with the upper recess-forming surface ix, and a lower inclined surface ic at a inclination degree that allows the engaging portion to be planarly engaged with the lower recess-forming surface iz, and a front spring holding portion if having a housing portion capable of housing the front portion of the spring wi and a holding protrusion for holding the tip portion of the spring wi. A spring wi is interposed between the engaging member i7 and the lower plate-shaped portion i31. The spring wi biases the engaging member i7 forward, i.e., toward the engaged portion i53, using the lower plate-shaped portion i31 as a foothold.

[0220] In the vertical position change mechanism IC, the inclination of the lower recess forming surface iz is set to be greater than the inclination of the upper recess forming surface ix. Therefore, the base IK and the headrest main body IH are configured so that they can be moved with a relatively light force when they are changed upward, and they can be moved with a heavier force when they are changed downward than when they are changed upward.

[0221] <Modifications of the vertical position change mechanism IC> The vertical position change mechanism IC need only be arranged between the frame mounting part IF and the base IK and capable of sliding the base IK in the vertical direction relative to the frame mounting part IF so that its position can be changed, and it goes without saying that its specific configuration can be modified in various ways.

[0222] Hereinafter, modified examples of the vertical position changing mechanism IC that is applied to the headrest I will be described with reference to FIGS.

[0223] The up-down position change mechanism IC is mainly composed of a guide rail i32 provided on the base IK, an engaged portion i53 provided on the base IK and having an engaging recess ia with which the tip of the engaging member i7 can selectively engage, left and right rail receiving portions i52 provided on the frame mounting portion IF, an engaging member holding portion i33 provided on the frame mounting portion IF, the engaging member i7 held by the engaging member holding portion i33, and a spring wi that urges the engaging member i7 toward the engaged portion i53 of the base IK.

[0224] In this embodiment, compared to the previously described embodiment, the front-to-rear positional relationship between the engaging member holding portion i33 that holds the engaging member i7 and the engaged portion i53 with which the tip of the engaging member i7 engages is reversed.

[0225] The engaging member i7 has tip engaging portions ie arranged in a pair on the left and right sides facing the lower part i3 of the base IK, a positioning protrusion ih arranged between the pair of tip engaging portions i8 on the left and right sides, and a rear spring holding portion if having an accommodating portion capable of accommodating the rear portion of the spring wi and a holding protrusion that holds one end of the rear end of the spring wi.

[0226] A spring wi is interposed between the engaging member i7 and the base member i5 of the frame attachment part IF. The spring wi biases the engaging member i7 backward, i.e., toward the engaged part i53 provided on the base part IK, using the frame attachment part IF as a foothold.

[0227] The tip engagement portion ie of the engagement member i7 has an upper inclined surface ib set at a degree of inclination that allows it to engage with the upper recess forming surface ix that constitutes the engagement recess ia, and has a lower inclined surface ic set at a degree of inclination that allows it to engage with the lower recess forming surface iz that constitutes the engagement recess ia.

[0228] The positioning protrusion ih can position the engaging member i7 by engaging with a positioning groove i54 extending in the vertical direction provided between a pair of left and right engaged portions i53 having engaging recesses ia protruding from the base KI.

[0229] The positioning protrusion ih has left and right side wall portions ih1 and a bottom wall portion ih2 disposed between the lower ends of the left and right side wall portions ih1. The left and right side wall portions ih1 are adapted to engage with upper movement limiting portions i55 protruding from the engaged portion i53, and the left and right side wall portions ih1 and the bottom wall portion ih2 are adapted to engage with lower movement limiting portions i56 protruding from the engaged portion i53.

[0230] As in the above-described embodiment, the vertical position change mechanism IC is configured such that the inclination of the lower recess forming surface iz is greater than the inclination of the upper recess forming surface ix. Therefore, the base IK and the headrest main body IH are configured to be moved with a relatively light force when changing the position upward, and are configured to be moved with a heavier force when changing the position downward than when changing the position upward.

[0231] <<Locking mechanism Rc>> The weight-sensing rocking mechanism Rc is configured to tilt the backrest E in accordance with the weight of the seated person. The weight-sensing rocking mechanism Rc is configured to move the seat C backward in response to the backward tilting of the backrest E, while lifting the seat C against the weight of the seated person.

[0232] The weight-sensing rocking mechanism Rc is mainly composed of a support base B attached to the upper end of the leg A, a seat C arranged on the support base B and configured so that its front part can move relative to the support base B via a front axis j2, a back support body D which is rotatably supported on the support base B via a main axis j1 and has a seat engagement axis j3 which is arranged in front of the main axis j1 and can engage with the front-to-rear center of the seat C, and a receiving axis d4 which is biased by a reaction spring wd so that they can move together, a backrest E supported by the back support body D, and a reaction spring wd which is arranged between the support base B and the back support body D and can apply a reaction force against the backward tilting movement of the backrest E.

[0233] <<Seat forward tilt mechanism G>> The seat forward tilt mechanism G is capable of changing the position of the seat C around the seat engagement axis j3 between a normal position (M) in which the seat surface is set so that the entire seat surface is in an approximately horizontal position, and a forward tilt position (F) in which the seat surface is tilted further forward than the normal position (M).

[0234] The seat forward tilt mechanism G is configured to allow the front axle j2 to be displaced vertically relative to the seat C, which is supported rotatably around the seat engagement shaft j3. When the seat forward tilt mechanism G is in operation, the front axle j2 is held at the lower end of the front axle support part b5 of the support base B and cannot be lowered any further.

[0235] The seat forward tilt mechanism G flexibly tilts the seat C forward when the weight of the seat occupant acts on the front part of the seat C. In other words, the seat forward tilt mechanism G is configured not to lock the rotation in the forward tilt position (F) direction when the weight of the seat occupant acts on the front part of the seat C with the seat C in the normal position (M).

[0236] Furthermore, the seat forward tilt mechanism G is configured so as not to lock the seat C in the forward tilted position (F) in that position.

[0237] The seat forward tilt mechanism G is provided with a spring wg between the seat C and the front axle j2, which urges the seat C toward the normal position (M) using the front axle j2 as a foothold. When the spring wg is compressed against the urging force due to the weight of the seat occupant, the seat forward tilt mechanism G lowers the front part of the seat C, allowing the seat C to assume the forward tilt position (F).

[0238] The upper end of the spring wg that constitutes the seat forward tilt mechanism G is configured to engage with an upper spring receiving portion 21 a provided on the lower surface side of an upper spring receiving member 2 attached to the seat receiving body 1.

[0239] The lower end of the spring wg that constitutes the seat forward tilt mechanism G is configured to engage with a lower spring receiving portion 41 provided on the upper part of a lower spring receiving member 4 attached to the front axle j2.

[0240] The lower spring receiving member 4 has a lower spring receiving portion 41 at its upper portion, and is provided with a seat engaging portion 42 at its lower portion which is formed so that its front-to-rear width dimension gradually decreases downward in a side view.

[0241] The seat C is provided with a lower spring receiving member retaining portion 13a which is recessed to correspond to the shape of the seat engaging portion 42 provided on the lower spring receiving member 4 and is configured to be able to fit into the seat engaging portion 42 in the normal position (M).

[0242] The seat engaging portion 42 of the lower spring receiving member 4 is formed so that the front-to-rear width dimension gradually becomes shorter toward the bottom, and the lower spring receiving member holding portion 13a is formed with a recess to correspond to the shape of the seat engaging portion 42 so that when the seat C returns from the forward tilted position (F) to the normal position (M), the lower spring receiving member holding portion 13a, which was spaced apart from the seat engaging portion 42, can smoothly engage with the seat engaging portion 42.

[0243] The chair of the above-described embodiment not only has a weight-sensing rocking mechanism Rc, but also utilizes the seat engagement axis j3, which is an essential component of the weight-sensing rocking mechanism Rc, to rotate the seat C around the seat engagement axis j3, thereby enabling the seat C to adopt a forward-leaning posture (F).

[0244] Furthermore, with the chair of the above-described embodiment, it is possible to provide the armrest K configured so that the armrest 7 can be moved forward and backward in a variety of directions relative to the armrest base KB.

[0245] Furthermore, the chair of the above-described embodiment can provide an armrest K that allows the operation for changing the up-down position of the armrest main body KH to be suitably performed.

[0246] As described above, the armrest K of the chair according to this embodiment is attached to the chair body when in use.

[0247] The armrest K comprises an arm support 5 attached to the chair body, and an armrest body KH supported on the arm support 5 so that its vertical position can be changed.

[0248] The armrest body KH is provided with an armrest support part 6 and an armrest 7 arranged so as to be slidable in the front-rear direction relative to the armrest support part 6, and an operating lever R for operating the armrest body KH so as to change its up-down position is arranged on the armrest 7.

[0249] This makes it possible to provide an armrest that allows operations to be conveniently performed to change the up-down position of the armrest body.

[0250] In other words, the operation for changing the up-down position of the armrest body KH can be performed by the user with his / her fingers effortlessly operating the operating lever R while keeping his / her hand on the armrest 7.

[0251] Moreover, the user can move the armrest main body KH up and down while grasping the armrest 7 with his / her hand and applying an operating force to the operating lever R while placing his / her hand on the armrest 7. Therefore, with the armrest K of this embodiment, the operation for moving the armrest main body KH up and down can be smoothly performed.

[0252] Furthermore, since the operating lever R is disposed on the armrest 7, which can slide in the forward and backward directions, the operability of the operating lever R does not change even if the position of the armrest 7 is changed in the forward and backward directions.

[0253] An operating lever R is rotatably supported on the elbow rest 7.

[0254] Therefore, the application of an operating force to the operating lever R by the user can be performed suitably.

[0255] An operating lever R is disposed at the front end of the armrest 7.

[0256] For this reason, the operating lever R is arranged on the front end side of the elbow rest 7, where the user's fingertips will naturally be positioned when the user places his or her hand on the elbow rest 7, making it easy for the user to operate.

[0257] The elbow support 5 has multiple engaged portions 521 arranged in the vertical direction, and the engaging member 9 arranged on the elbow rest support portion 6 selectively engages with the multiple engaged portions 521, thereby determining the vertical position of the armrest main body KH relative to the elbow support 5.

[0258] An operating force applied to the operating lever R is transmitted to the engaging member via the wire member wy.

[0259] Therefore, even if the position of the elbow rest 7 is changed in the front-rear direction, the operating force applied to the operating lever R is transmitted to the engagement member 9 via the wire member wy.

[0260] In other words, by utilizing the wire member wy, a configuration is preferably realized that allows the armrest body KH to move up and down smoothly even when the operating lever R is arranged on the armrest 7.

[0261] The elbow rest support portion 6 has a lower wire member arrangement space 63, which is an arrangement space in which a part of the wire member wy can be arranged, and the elbow rest 7 has an elbow rest base 71 that rotatably supports the operating lever R, and an elbow rest pad 72 arranged on the elbow rest base 71, and has an upper wire member arrangement space sp between the elbow rest base 71 and the elbow rest pad 72, which is an arrangement space in which a part of the wire member wy can be arranged, and a second guide slit S2, which is a wire member communication hole that penetrates in the vertical direction and allows a part of the wire member wy to pass through, is formed in the elbow rest base 71.

[0262] Therefore, the wire member wy is suitably disposed between the operating lever R and the engaging member 9.

[0263] It comprises an engagement unit TU attached to the elbow rest support part 6, and the engagement unit TU comprises a unit base 8 attached to the elbow rest support part 6, an engagement member 9 arranged movable relative to the unit base 8 between an engagement position (F) at which it can engage with the engaged part 521 and a retracted position (not shown) retracted from the engagement position (F), and a spring wt arranged between the unit base 8 and the engagement member 9 for urging the engagement member 9 towards the engagement position (F).

[0264] Therefore, the engagement unit TU makes it possible to handle a plurality of parts and assemble them to the elbow rest support portion 6 in an efficient manner.

[0265] The elbow rest 7 comprises an elbow rest base 71 that rotatably supports the operating lever R, and an elbow rest pad 72 arranged on the elbow rest base 71. The elbow rest pad 72 is provided with an elastic biasing portion 724 that engages with the operating lever R and biases the operating lever R in the direction of the initial position (D).

[0266] Therefore, the operating lever R, which receives the operating force from the user, can be suitably returned to the initial position (D).

[0267] An elbow rest guide mechanism Q is provided between the elbow rest support part 6 and the elbow rest 7, which slides the elbow rest 7 on a predetermined trajectory between a most forward position (F) and a most rearward position (R).

[0268] For this reason, the armrest K has a suitable structure that allows the armrest 7 to slide in the front-rear direction.

[0269] The chair of this embodiment includes a chair body and armrests K attached to the chair body. Therefore, the chair includes the armrests K that contribute to comfortable use by the user.

[0270] It should be noted that the present invention is not limited to the embodiment described above in detail.

[0271] The elbow rest may be any member that is slidably disposed in the front-rear direction relative to the elbow rest support portion. For example, the elbow rest may have a single sliding path.

[0272] The operating lever may be any one that is provided on the elbow rest, and the manner and location of attachment thereof may be set in various ways.

[0273] The operating lever does not have to be supported rotatably with respect to the elbow rest, but may be supported slidably with respect to the elbow rest.

[0274] The operating force applied to the operating lever may be transmitted to the engaging member via an operating force transmission mechanism that does not use a wire member.

[0275] 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]

[0276] 5...Elbow support 6...Elbow support 7. Elbow pad K…Armrest KH…Armrest body R…Operating lever wy…Wire material

Claims

1. An armrest that is attached to a chair body and used, The armrest comprises an arm support attached to the chair body, and an armrest body supported on the arm support so that its vertical position can be changed, The armrest body includes an armrest support portion and an armrest arranged to be slidable in the front-rear direction relative to the armrest support portion, An operating lever for operating the armrest body so as to change the up and down position is disposed on the armrest.

2. 2. The armrest according to claim 1, wherein the operating lever is rotatably supported relative to the armrest.

3. 2. The armrest according to claim 1, wherein the operating lever is disposed at a front end of the armrest.

4. The elbow support has a plurality of engaging portions arranged in parallel in the vertical direction, The engaging member disposed on the armrest support portion selectively engages with the plurality of engaged portions, thereby defining the vertical position of the armrest body relative to the arm support; 2. The armrest according to claim 1, wherein an operating force applied to said operating lever is transmitted to said engaging member through a wire member.

5. The elbow support portion has an arrangement space in which a portion of the wire member can be arranged, the elbow rest comprises an elbow rest base which rotatably supports the operating lever, and an elbow rest pad disposed on the elbow rest base, and has an arrangement space between the elbow rest base and the elbow rest pad in which a portion of the wire member can be arranged, 5. The armrest according to claim 4, wherein the armrest base is formed with a wire member communication hole that penetrates vertically and allows a portion of the wire member to pass therethrough.

6. An engagement unit is attached to the elbow rest support portion, The armrest of claim 4, wherein the engagement unit comprises a unit base attached to the elbow support portion, an engagement member arranged to be movable relative to the unit base between an engagement position at which it can engage with the engaged portion and a retracted position retracted from the engagement position, and a spring arranged between the unit base and the engagement member for urging the engagement member toward the engagement position.

7. The elbow rest includes an elbow rest base that rotatably supports the operating lever, and an elbow rest pad disposed on the elbow rest base, 2. The armrest according to claim 1, wherein the armrest pad is provided with an elastic biasing portion that engages with the operating lever and biases the operating lever in the direction of the initial position.

8. 2. The armrest according to claim 1, further comprising an armrest guide mechanism provided between said armrest support portion and said armrest for sliding said armrest along a predetermined trajectory between a most forward position and a most rearward position.

9. A chair comprising a chair body and an armrest according to any one of claims 1 to 8 attached to the chair body.

Images