chair

Abstract

To provide a chair that maintains the operability of the control panel while improving the design and durability of the seat. [Solution] A chair according to one aspect of the present invention comprises a seat having a core member and a surface material covering the core member, and an operating unit for operating the chair's operating mechanism. The core member comprises an upper surface portion constituting the seating surface of the seat, and an outer surface portion including outer surfaces extending downward from both left and right edges of the upper surface portion and a lower surface connected to the lower end of the outer surfaces. The surface material has a peripheral edge portion in the portion facing the outer surface portion. The operating unit comprises a fixing member provided on an exposed portion of the outer surface portion that is not covered by the surface material, and an operating part supported so as to be relatively movable by the fixing member and connected to the operating mechanism. At least a part of the operating part is on the outside in the left and right direction relative to the exposed portion, and faces in the vertical direction relative to the portion of the surface material that covers the outer surface portion.

Description

Technical Field

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[0001] The present invention relates to a chair.

Background Art

[0002] As a seat of a chair, for example, Patent Document 1 below discloses a configuration in which a skin material that collectively covers a seat plate and a cushion body is provided so as to wrap around to the lower surface of the seat plate (see, for example, Patent Document 1 below). On the other hand, an operation lever for operating the operation mechanism of the chair is mounted on this type of seat. In the seat described in Patent Document 1 below, an opening as a relief portion for exposing the operation lever is formed in a portion of the skin material that is located on the outer surface of the seat.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the above prior art, since the relief portion is formed by cutting a part of the skin material, there is a possibility that the skin material may fray or break starting from the opening edge of the relief portion.

[0005] The present invention provides a chair that can improve the design and durability as a seat while maintaining the operability of the operation part.

Means for Solving the Problems

[0007] According to this embodiment, the fixing member is fixed to the portion of the core member that is not covered by the outer material (exposed portion), so that the fixing member can be attached to the core member without forming an opening or the like in a part of the outer material. Furthermore, since at least a part of the operating section is positioned on the outside in the left-right direction relative to the exposed portion and facing the outer material in the vertical direction, it is easy to position the operating section within reach of the seated person. As a result, it is possible to improve the design and durability of the seat while maintaining the operability of the control section.

[0008] (2) In the chair according to the embodiment of (1) above, it is preferable that the outer surface is an inclined surface that extends outward in the left-right direction as it goes upward, and that the operating part faces the inclined surface in the vertical direction. According to this embodiment, the seated person is guided to the operating section by extending their hand along the outer surface of the core member. In this case, access to the operating section is easier compared to, for example, when the outer surface of the core member is formed perpendicular to the horizontal plane. As a result, further improvements in operability can be achieved.

[0009] (3) In the chair according to the embodiment of (2) above, the operating part is movable outward in the left-right direction from its initial position on a virtual surface inclined upward with respect to the horizontal plane, and it is preferable that the vertical distance between the operating part and the outer surface increases as the amount of movement of the operating part from the initial position increases. According to this embodiment, interference between the surface material and the operating part can be suppressed when the operating part moves. This suppresses damage to the surface material and improves the durability of the seat.

[0010] (4) In a chair according to any of the embodiments described in (1) to (3) above, it is preferable that a cushioning material is interposed between the outer surface and the surface material. According to this embodiment, the impact and other shocks that occur when the hand touches the seat while operating the control unit can be mitigated. This improves the operability of the control unit.

[0011] (5) In a chair according to any of the embodiments of (1) to (4) above, it is preferable that the fixing member extends outward in the left-right direction from the exposed portion and has an outer end that faces in the vertical direction with respect to the portion of the surface material that covers the outer surface, and that the operating portion is supported by the outer end. According to this embodiment, the peripheral edge of the surface material is set on the inner side in the left-right direction of the outer surface, making it easier to position the fixing member on the outer side in the left-right direction. This makes it possible to improve the design and durability of the seat while maintaining the operability of the operating part.

[0012] (6) In a chair according to any of the embodiments of (1) to (5) above, it is preferable that the surface material covers the upper surface from above and also covers a part of the outer surface via the outer peripheral edge of the upper surface. According to this embodiment, the core member is covered by the surface material from the top to the sides. Therefore, the aesthetic design of the seat can be improved. [Effects of the Invention]

[0013] According to each of the above aspects, it is possible to improve the design and durability as a seat while maintaining the operability of the operation unit.

Brief Description of the Drawings

[0014] [Figure 1] It is a perspective view of the chair according to the first embodiment seen from the right rear. [Figure 2] It is a partial side view of the chair according to the first embodiment. [Figure 3] It is a cross-sectional view corresponding to line III-III of FIG. 1. [Figure 4] It is a view of FIG. 2 showing a part of the support base according to the first embodiment broken away and viewed in the direction of arrow IV. [Figure 5] It is a cross-sectional view corresponding to line V-V of FIG. 4. [Figure 6] It is an exploded perspective view of the upper structure according to the first embodiment. [Figure 7] It is a cross-sectional view corresponding to line VII-VII of FIG. 2. [Figure 8] It is a perspective view around the connecting rod portion according to the first embodiment. [Figure 9] It is a cross-sectional view corresponding to line IX-IX of FIG. 8. [Figure 10] It is a cross-sectional view corresponding to line X-X of FIG. 2. [Figure 11] It is a cross-sectional view of the chair according to the first embodiment showing the reclining state. [Figure 12] In the chair according to the second embodiment, it is a rear view around the seat. [Figure 13] In the chair according to the second embodiment, it is an exploded perspective view of the seat seen from below. [Figure 14] In the chair according to the second embodiment, it is an exploded perspective view of the seat seen from below. [Figure 15] It is a cross-sectional view corresponding to line XV-XV of FIG. 13. [Figure 16] It is a cross-sectional view corresponding to line XVI-XVI of FIG. 14. [Figure 17] It is a cross-sectional view corresponding to line XVII-XVII of FIG. 14. [Figure 18] This is a cross-sectional view corresponding to line XVIII-XVIII in Figure 14. [Figure 19] This diagram shows the second operating section in the pulled-out position and is a cross-sectional view corresponding to Figure 17. [Modes for carrying out the invention]

[0015] Next, embodiments of the present invention will be described with reference to the drawings. In the embodiments and modifications described below, corresponding components may be denoted by the same reference numerals and their descriptions omitted. In the following description, expressions indicating relative or absolute arrangements such as "parallel," "orthogonal," "center," and "coaxial" will not only strictly represent such arrangements, but will also represent states in which the surfaces are relatively displaced by an angle or distance that allows for tolerances or the same function to be obtained. Furthermore, in this embodiment, "facing each other" is not limited to cases where the orthogonal directions (normal directions) of the two surfaces coincide with each other, but also includes cases where the orthogonal directions intersect.

[0016] (First Embodiment) [Chair 1] Figure 1 is a perspective view of chair 1 from the right rear. Figure 2 is a partial side view of chair 1. As shown in Figures 1 and 2, the chair 1 comprises a support structure 2, a seat 3, an upper structure 4, and an operating unit 5. The chair 1 is configured such that the seat 3 is displaced backward and downward in conjunction with the reclining movement of the upper structure 4. In the following description, directions such as front, back, up, down, left, and right are the same as the direction of a person (sitter) sitting in the chair 1 in a normal posture. In this case, the arrow UP in the figures indicates upward, the arrow FR indicates forward, and LH indicates left. Also, in the following description, in the front-back, up-down, and left-right directions, the side away from the center of the chair 1 may be referred to as the outside, and the side toward the center of the chair 1 may be referred to as the inside.

[0017] <Support structure 2> The support structure 2, while in contact with the floor surface F, supports the seat 3 and the upper structure 4 from below. The support structure 2 comprises a leg 11 and a base 12. The leg body 11 comprises a multi-branched leg 15 and a leg column 16. Each leg of the multi-legged structure 15 is fitted with a caster 17 that allows it to move on the floor surface F. However, the casters 17 are not an essential component. For example, the leg body 11 may be in contact with the floor surface F via adjusters or the like instead of casters 17.

[0018] Figure 3 is a cross-sectional view corresponding to the line III-III in Figure 1. As shown in Figures 1 and 3, the leg column 16 extends upward from the central part of the multi-legged leg 15. The leg column 16 has a gas spring 18 built into it, which is the lifting mechanism of the chair 1. The gas spring 18 is configured such that an inner cylinder 18a is supported so as to be able to move up and down and rotate relative to an outer cylinder (not shown) provided inside the leg cover 19, for example. An operating pin 18b for extending and retracting the gas spring 18 protrudes upward from the inner cylinder 18a. In other words, the gas spring 18 can extend and retract (move forward and backward relative to the outer cylinder) when the operating pin 18b is pushed in.

[0019] Figure 4 is a view taken from arrow IV in Figure 2, showing a portion of the support base 12 broken away. As shown in Figures 3 and 4, the support base 12 is a box-shaped support mechanism (support base) that is connected to the seat 3 and the superstructure 4 at the upper end of the support structure 2. The support base 12 comprises a casing 21, a tilting mechanism 22, and a linkage mechanism 23.

[0020] The casing 21 is connected to the upper end of the leg column 16 (inner cylinder 18a). In the side view shown in Figure 2, the casing 21 is formed in a box shape that is flattened vertically. As shown in Figure 3, a housing hole 21b is formed at the rear end of the casing 21, penetrating vertically through the bottom wall portion 21a of the casing 21. The upper end of the leg column 16 is inserted into the casing 21 from below through the housing hole 21b. As a result, the casing 21 is cantilevered to the leg column 16, tilting upward as it moves forward. The operating pin 18b of the gas spring 18 protrudes into the casing 21 through the housing hole 21b.

[0021] In the plan view shown in Figure 4, the casing 21 is formed in a triangular shape, with its width gradually increasing in the left-right direction towards the front. As shown in Figures 2 and 4, a lateral connecting port 21c is formed at the front end of the casing 21, allowing the inside and outside of the casing 21 to communicate in the left-right direction. The lateral connecting port 21c is formed by opening a portion of the side wall portion 21d located on both sides of the casing 21 in the left-right direction.

[0022] As shown in Figure 3, an upward-opening upper connection port 21e is formed at the front of the casing 21. The upper connection port 21e communicates with a lateral connection port 21c. The portion of the casing 21 located behind the upper connection port 21e constitutes the top wall portion 21f. In a plan view, the top wall portion 21f faces the lower surface of the base 3 with a vertical gap between them, at least in the portion that overlaps with the leg column 16.

[0023] In the bottom wall portion 21a, a pair of left and right support walls 24 are provided in the portion located between the housing hole 21b and the lateral connecting port 21c. The support walls 24 extend upward from the bottom wall portion 21a with the left-right direction as the thickness direction. The support walls 24 may be integrally formed with the casing 21, or separate support walls 24 may be fixed to the casing 21.

[0024] The tilting mechanism 22 connects the base 12 and the seat 3, and the base 12 and the superstructure 4. In other words, in the chair 1 of this embodiment, the seat 3 and the superstructure 4 are connected to each other via the base 12. The tilting mechanism 22, together with the seat 3, constitutes a so-called four-bar linkage mechanism. The tilting mechanism 22 includes a front link 25 and a rear link 26.

[0025] As shown in Figures 3 and 4, the front link 25 is provided at the front end of the casing 21. Specifically, the front link 25 comprises a front base 28 and a pair of overhangs 29 (see Figure 4). The front base 28 is housed at the front end of the casing 21. The front base 28 is supported at its rear end by the casing 21 via the main shaft 31 (see Figure 3). The main shaft 31 is provided to traverse the casing 21 in the left-right direction. Specifically, both ends of the main shaft 31 in the left-right direction pass through the support wall 24 in the left-right direction and are then supported by the portion of the side wall 21d located behind the lateral linkage opening 21c. As a result, the front link 25 is provided so as to be rotatable relative to the casing 21 around the axis of the main shaft 31 (main axis C1). In this embodiment, the front link 25 is rotatable so as to be displaceable in the vertical direction at its front end.

[0026] As shown in Figure 4, the protruding portions 29 each project outward in the left-right direction from the front end of the front base 28. Each protruding portion 29 projects outward from the casing 21 through the corresponding lateral connection opening 21c.

[0027] As shown in Figure 3, the rear links 26 are located within the casing 21, behind the front links 25. The rear links 26 are provided in pairs, left and right. Each rear link 26 extends in a manner that is inclined backward as it extends upward. The rear links 26 are supported at their lower ends by the support wall 24 via a lower shaft member 33. In the illustrated example, the lower shaft member 33 is located in the support wall 24, behind and above the main shaft 31. The lower shaft member 33 is located in front of the leg column 16. The rear links 26 are rotatable relative to the support wall 24 (casing 21) around the axis of the lower shaft member 33 (lower axis C2).

[0028] The linkage mechanism 23 is a mechanism for linking the operating unit 5 and the gas spring 18. The linkage mechanism 23 is located in the casing 21 in a part that is rearward of the lower shaft member 33. The linkage mechanism 23 is located above the housing hole 21b and is rotatable around an axis that runs in the left-right direction. The linkage mechanism 23 rotates in conjunction with the operation of the operating unit 5, thereby pushing in the operating pin 18b.

[0029] <Location 3> As shown in Figures 1 and 4, the seat 3 is formed in a circular or rectangular shape in plan view, and supports the seater's buttocks and thighs from below on its upward-facing seating surface 3a. The seat 3 comprises a seat support member 38 and a seat body 39.

[0030] As shown in Figures 3 and 4, the seating member 38 is connected to the support base 12 while covering the casing 21 from above. Specifically, the seating member 38 comprises a seating plate 41, a pair of outer connecting pieces 42, and a pair of inner connecting pieces 43. The seat support plate 41 is positioned above the support base 12, with its thickness oriented vertically. The seat support plate 41 protrudes outward in the left-right direction relative to the casing 21.

[0031] The outer connecting piece 42 protrudes downward from the seat plate 41, spaced apart in the left-right direction. The outer connecting piece 42 extends over the entire front-rear area of ​​the seat plate 41, excluding the front and rear ends. In a side view, the outer connecting piece 42 covers at least a portion of the rear link 26 described above from the outside in the left-right direction. The length of the outer connecting piece 42 in the front-rear direction can be changed as appropriate.

[0032] The front end of the outer connecting piece 42 is connected to the front end of the front base 28 via the seat support shaft 45 within the upper linkage opening 21e. The seat support shaft 45 extends parallel to the main shaft 31 in a portion located in front of and above the main shaft 31. The seat support shaft 45 is rotatably connected to the outer connecting piece 42 and the front base 28 around an axis (seat support axis C3) that runs along the left-right direction. The seat receiving member 38 is configured to be rotatable around the seat support axis C3 relative to the front link 25 and to revolve around the main axis C1 relative to the support base 12. That is, the front end of the seat 3 is rotatable so as to be displaced vertically and longitudinally relative to the support base 12. Specifically, the front end of the seat 3 is displaceable upward and backward relative to its initial state. The position of the seat support shaft 45 relative to the main shaft 31 can be changed as appropriate. That is, the seat support shaft 45 may be coaxial with the main shaft 31, or it may be positioned rearward or below the main shaft 31.

[0033] The inner connecting piece 43 protrudes downward from a portion located inward in the left-right direction relative to the pair of outer connecting pieces 42 at the center of the seat plate 41 in the front-rear direction, with a gap in the left-right direction. At least a portion of the inner connecting piece 43 is covered by the outer connecting piece 42 from the outside in the left-right direction when viewed from the side. As shown in Figure 3, the inner connecting piece 43 is connected to the upper end of the rear link 26 via the upper shaft member 46 within the upper linkage opening 21e. The upper shaft member 46 extends parallel to the lower shaft member 33 in a portion located rearward and above the lower shaft member 33. The upper shaft member 46 is connected so as to be rotatable relative to the inner connecting piece 43 and the upper end of the rear link 26 around an axis (upper axis C4) that runs along the left-right direction. That is, the rear end of the seat 3 can be displaced downward and rearward in relation to the upward and rearward displacement of the front end of the seat 3 from its initial state. The position of the lower shaft member 33 relative to the upper shaft member 46 can be changed as appropriate.

[0034] The seat body 39 is supported from below by the seat support member 38. The seat body 39 comprises a main part 39a and a downward-sloping front part 39b. The main portion 39a is the part that constitutes the plan view outline of the seat 3. The main portion 39a protrudes from the seat support member 38 on both sides in the left-right direction and to the rear. The rear end edge of the main portion 39a is located behind the rear end of the support base 12. The downward-sloping portion 39b is the part that extends downward from the front end of the main portion 39a. In a front view, the downward-sloping portion 39b overlaps with the front end of the support base 12. Of the seat body 39, at least the portion from the upper surface of the main portion 39a to the front surface of the downward-sloping portion 39b functions as the seating surface 3a when seated.

[0035] Here, since the seat 3 (seat support member 38) is connected to the rear link 26 at its central part in the front-rear direction, a vertical gap is created between the rear of the seat 3 and the rear of the support base 12. In other words, the rear of the seat 3 extends backward from the support base 12 as if it were cantilevered. Note that it is sufficient for a vertical gap to exist between the seat 3 and the support base 12 at least at a position where it overlaps with the leg column 16 in a plan view.

[0036] Figure 5 is a cross-sectional view corresponding to the VV line in Figure 4. As shown in Figures 3 and 5, the seat body 39 comprises a seat shell 50, a cushioning material 51, and a surface material 52. The seat shell 50 is formed from a hard material such as synthetic resin or metal, and functions as a structural member of the seat body 39. The seat shell 50 is formed over the main part 39a and the downward-sloping front part 39b of the seat body 39. Specifically, the seat shell 50 is formed in a box shape that is open to the front and top. In a plan view, the seat shell 50 is formed to protrude from the seat support plate 41 in the front-rear and left-right directions.

[0037] In the cross-sectional view shown in Figure 5, the seat shell 50 comprises an opposing portion 50a facing the seat support plate 41 and an outer portion 50b extending outward from the opposing portion 50a in the left-right direction. In this embodiment, the opposing portion 50a is a region that overlaps in plan view with the receiving recess 50f formed on the lower surface of the seat shell 50. That is, the lower surface of the opposing portion 50a (the top surface of the receiving recess 50) constitutes at least a part of the lower surface of the seat body 39 (seat shell 50). The seat support plate 41 is housed in the receiving recess 50f so as to face the top surface of the receiving recess 50f. The seat support plate 41 is fixed to the opposing portion 50a (the top surface of the receiving recess 50f) via screws or the like. The depth of the receiving recess 50f is formed to be equal to the thickness of the seat support plate 41.

[0038] The outer portion 50b is formed as an inclined surface that extends upward as it extends outward in the left-right direction. Specifically, the outer portion 50b is formed in a protruding arc shape toward the left-right direction. The outer portion 50b is formed such that the angle with the horizontal plane increases as it moves further outward in the left-right direction.

[0039] An outer peripheral recess 50c is formed at the boundary between the opposing portion 50a and the outer portion 50b of the seat shell 50. The outer peripheral recess 50c is formed along the outer shape of the seat support plate 41 (see Figure 4). That is, the outer peripheral recess 50c is formed along the outer peripheral portion of the receiving recess 50f. Therefore, the inner peripheral surface of the outer peripheral recess 50c and the inner peripheral surface of the receiving recess 50f coincide. In a plan view, the outer peripheral end of the seat support plate 41 overlaps with a part of the outer peripheral recess 50c (the inner end in the width direction of the outer peripheral recess 50c).

[0040] The lower surface of the opposing portion 50a is positioned above the portion of the lower surface of the seat shell 50 other than the opposing portion 50a, at a height equivalent to the thickness of the seat support plate 41. The seat support plate 41 is surrounded by the inner surface of the receiving recess 50f (outer peripheral recess 50c). In other words, the seat support plate 41 is shielded from the outside in the left-right direction by the lower end of the outer portion 50b.

[0041] The cushioning material 51 is provided on at least the portion of the seat shell 50 that faces (overlaps with) the seating surface 3a, and elastically supports the sitter. In this embodiment, the cushioning material 51 covers the upper surface of the seat shell 50 and also covers the seat shell 50 from below by wrapping around the outer edge of the seat shell 50 to the bottom of the seat shell 50. In this embodiment, the portion of the cushioning material 51 housed inside the seat shell 50 constitutes the main cushion portion 51a, and the portion located outside the seat shell 50 constitutes the outer cushion portion 51b. In the illustrated example, the end edge of the outer cushion portion 51b is located outside the opposing portion 50a in the left-right direction and is positioned facing the outer portion 50b. The main cushion portion 51a and the outer cushion portion 51b may be separate or integrated.

[0042] The seat support plate 41, seat shell 50, and cushioning material 51 constitute the core member 150 that forms the outer shape of the seat 3. In this case, the upper surface of the main cushion portion 51a constitutes the seating surface 3a as the upper surface of the core member 150. The lower surface of the seat support plate 41 constitutes the lower surface of the core member 150, and the outer surface of the outer portion 50b constitutes the outer surface of the core member 150. Therefore, the outer surface of the outer portion 50b and the lower surface of the seat support plate 41 function as the outer surface portion of the core member 150, including the outer surface located on both sides in the left-right direction, and the lower surface connected to the lower end of the outer surface. In this case, the outer surface portion also includes the inner surface of the outer peripheral recess 50c and other surfaces that constitute the outer shape of the core member 150.

[0043] The upholstery material 52 forms the outer surface of the seat body 39, including the seating surface 3a, and covers the seat shell 50 and cushioning material 51 together. The upholstery material 52 covers the seat shell 50 from above and also covers the seat shell 50 from the sides down to the bottom. Specifically, the upholstery material 52 comprises a seating surface component 52a and an exterior component 52b. The seat surface component 52a is the part of the seat body 39 that is exposed to the outside as the seat surface 3a. The seat surface component 52a covers the seat shell 50 (upper part) from above, sandwiching the main cushion portion 51a.

[0044] The exterior component 52b is integrally connected to the seat surface component 52a at its outer peripheral edge. The exterior component 52b is the part of the seat body 39 that is exposed to the outside, other than the seat surface 3a. Specifically, the exterior component 52b covers the seat shell 50 from the sides and below, sandwiching the outer peripheral cushion portion 51b. That is, the exterior component 52b is formed in a curved shape that protrudes outward in the left-right direction, following the outer portion 50b.

[0045] The outer periphery (periphery) of the exterior component 52 is positioned inward in the left-right direction from the outer cushion portion 51b, and facing the outer surface of the core member 150. The periphery of the exterior component 52b is provided with a fixed end 52b1. The fixed end 52b1 is the portion of the periphery of the exterior component 52b that is fixed to the seat shell 50. The fixed end 52b1 is folded at the boundary between the outer portion 50b and the outer recess 50c, and then enters into the outer recess 50c. The fixed end 52b1 is fixed to the inner surface of the outer recess 50c using a stapler or the like. Therefore, the portion of the lower surface of the seat 3 that is located inside the outer recess 50c functions as an exposed portion 55 that is not covered by the surface material 52. Note that a part of the periphery of the exterior component 52b may overlap with the seat support plate 41 in a plan view within the outer recess 50c. Furthermore, the entire peripheral edge of the exterior component 52b, including the fixed end 52b1, may be located outside the seating plate 41 (outer peripheral recess 50c). In other words, the peripheral edge of the exterior component 52b only needs to be positioned facing the outer surface of the core member 150.

[0046] The top surface of the outer peripheral recess 50c is positioned at an upward spacing relative to the upper surface of the seating plate 41. This makes it easier to secure a fixing area for the fixed end 52b1 on the inner surface of the outer peripheral recess 50c. However, the outer peripheral recess 50c may be positioned at an outward spacing relative to the receiving recess 50f. Alternatively, there may be a configuration without an outer peripheral recess 50c (where the top surfaces of the outer peripheral recess 50c and the receiving recess 50f are flush). In this case, it is preferable that the fixed end 52b1 is fixed to the inner peripheral surface of the receiving recess 50f.

[0047] <Superstructure 4> Figure 6 is an exploded perspective view of the superstructure 4. As shown in Figures 1 and 6, the upper structure 4 incorporates the functions of both an armrest 100 and a backrest 101. The upper structure 4 comprises a pair of upright members 60, a backrest body 61, and a connecting part 62. Each of the upright members 60 is a molded product integrally formed from, for example, a metal material (such as aluminum). Each upright member 60 connects the base 12 and the backrest body 61. Each upright member 60 is provided on both sides in the left-right direction relative to the seat 3. Each upright member 60 has a symmetrical configuration. Therefore, the details of the upright members 60 will be described below using one of the upright members 60 on the left-right side as an example.

[0048] The upright member 60 is formed in an L-shape in both a plan view and a side view. Specifically, the upright member 60 comprises a horizontal rod portion 65, a vertical rod portion 66, and a connecting rod portion 67. As shown in Figures 4 and 6, the transverse rod portion 65 extends in the left-right direction below the seat 3. The transverse rod portion 65 has an insertion opening 65a that opens inward in the left-right direction. The protruding portion 29 of the front link 25 is fixed to the transverse rod portion 65 by being inserted into the transverse rod portion 65 through the insertion opening 65a. As shown in Figure 3, the upright member 60 can revolve around the main axis C1 as the front link 25 rotates around the main axis C1. The transverse rod portion 65 extends from below the seat 3 to the side, inclining upward as it moves outward in the left-right direction. In the illustrated example, the lower surface of the transverse rod portion 65 smoothly connects to the lower surface of the casing 21. Also, as shown in Figure 2, the transverse rod portion 65 is close to or in contact with the front downward portion 39b from the rear. In this case, at least a portion of the horizontal rod portion 65 is covered from the front by the downward-sloping portion 39b when viewed from the front.

[0049] As shown in Figures 2 and 6, the vertical rod portion 66 extends upward from the left-right outer end of the horizontal rod portion 65. The vertical rod portion 66 extends in the left-right outer region relative to the seat 3, and in a side view, it straddles the seat 3 in the vertical direction. The vertical rod portion 66 extends with a backward inclination as it goes upward. In a side view, the inclination angle of the vertical rod portion 66 with respect to the front-rear direction is the same as the inclination angle of the downward-sloping front portion 39b with respect to the front-rear direction. In addition, the front-rear dimension of the vertical rod portion 66 gradually increases as it goes upward. Note that the portion of the inner surface of the vertical rod portion 66 that intersects with the seat 3 (seat body 39) may be in contact with the surface of the seat body 39 that faces outward in the left-right direction. In this case, the inner surface of the vertical rod portion 66 may be in contact with the seat body 39 in such a way that it presses it inward in the left-right direction. However, there may be a gap between the inner surface of the vertical rod portion 66 and the seat body 39 that is small enough to prevent fingers or other objects from entering (for example, about 5 mm).

[0050] Figure 7 is a cross-sectional view corresponding to the line VII-VII in Figure 2. As shown in Figures 6 and 7, the vertical rod portion 66 is formed in a flattened shape with the front-to-back direction as the longitudinal direction and the left-to-right direction as the short direction in a cross-sectional view perpendicular to the vertical direction. In the illustrated example, the vertical rod portion 66 extends with its outer surface curving inward in the left-to-right direction as it moves forward, so that the left-to-right dimension gradually decreases as it moves forward. The cross-sectional shape of the vertical rod portion 66 can be changed as appropriate, such as to be rectangular or circular.

[0051] Figure 8 is a perspective view of the area around the connecting rod 67. As shown in Figures 6 and 8, the connecting rod portion 67 functions as a connecting portion between the backrest body 61 and the upright member 60. The connecting rod portion 67 protrudes upward from a part of the upper end surface of the vertical rod portion 66 and extends backward from the vertical rod portion 66. The connecting rod portion 67 is flattened in the left-right direction and extends cantilevered backward from the vertical rod portion 66. Of the upper end surface of the vertical rod portion 66, the portions extending forward from both sides in the left-right direction relative to the connecting rod portion 67 (the portions that do not overlap with the connecting rod portion 67 in a plan view) constitute a stepped surface 66a.

[0052] Figure 9 is a cross-sectional view corresponding to the IX-IX line in Figure 8. As shown in Figures 8 and 9, the connecting rod 67 is formed in a frustoconical shape, with its dimensions gradually decreasing in the front-to-back and left-to-right directions as it extends upward. The vertical dimension H67 (maximum dimension) of the connecting rod 67 is smaller than the vertical dimension H66 of the vertical rod 66 (see Figure 2). Note that the dimension H66 of the vertical rod 66 shown in Figure 3 is the dimension in the extending direction of the vertical rod 66.

[0053] The connecting rod portion 67 has a dimension T67 in the front-rear direction that is greater than the dimension T66 of the vertical rod portion 66 in the front-rear direction. In this embodiment, the dimension T67 of the connecting rod portion 67 and the dimension T66 of the vertical rod portion 66 are the maximum dimensions in the front-rear direction. In the example in Figure 9, the upper surface of the connecting rod portion 67 is formed as a flat surface perpendicular to the vertical direction. On the other hand, the lower surface of the connecting rod portion 67 is formed as an inclined surface that extends upward as it approaches the rear.

[0054] Figure 10 is a cross-sectional view corresponding to line XX in Figure 2. As shown in Figure 10, in a cross-sectional view perpendicular to the vertical direction, the connecting rod 67 extends with its outer surface curving inward in the left-right direction as it moves forward, so that its left-right dimension gradually decreases as it moves forward.

[0055] As shown in Figures 1 and 6, the backrest body 61 connects the upright members 60 to each other by wrapping around the seat 3 from the rear end above it. The backrest body 61 comprises an inner shell 70 and an outer material 71. The inner shell 70 forms the framework of the backrest body 61. The inner shell 70 is made of a different material than the upright member 60. In this embodiment, the inner shell 70 is a molded product integrally formed by, for example, stamping a synthetic resin material. That is, in the upper structure 4, the upright member 60 is made of a material with higher rigidity than the inner shell 70. The inner shell 70 may also be formed by injection molding or the like.

[0056] As shown in Figures 6 and 10, the inner shell 70 comprises a shell body 75 and a shell projection 76. The shell body 75 is the part of the inner shell 70 that mainly forms the frame of the backrest 101. In a plan view, the shell body 75 is positioned so that at least a part of it overlaps with the rear end of the seat 3. In a plan view, the shell body 75 extends in the left-right direction, following the shape of the rear end of the seat 3. The shell body 75 has its thickness in the front-back direction and extends in the up-down direction. In a side view, the shell body 75 extends while sloping backward as it goes upward, and then extends further upward. In a front view, the shell body 75 extends outward in the left-right direction while curving downward as it goes downward. Note that the shell body 75 may extend linearly in the left-right direction in a plan view, for example, as long as it has at least a surface facing forward.

[0057] Each shell projection 76 is located at the lower end of the shell body 75 and protrudes forward from both ends in the left-right direction. Each shell projection 76 has a symmetrical configuration. Therefore, the details of the shell projection 76 will be described below using one of the shell projections 76 in the left-right direction as an example.

[0058] The shell projection 76 comprises an outer plate 81 and a bulging portion 82. The outer plate 81 is the part of the inner shell 70 that mainly forms the frame of the armrest 100. The outer plate 81 extends forward from the shell body 75 so as to be continuous with the outer surface of the shell body 75. The outer plate 81 is flattened in the left-right direction and extends in the front-back direction. Specifically, in a plan view, the outer plate 81 extends outward in the left-right direction as it moves forward, and then extends inward in the left-right direction as it moves further forward. In the illustrated example, the outer plate 81 is formed in a curved shape with a projection on the left-right outward side.

[0059] The lower end surface of the outer plate 81 is flush with the lower end surface of the shell body 75, and together with the lower end surface of the shell body 75, it constitutes the lower end surface of the inner shell 70. As shown in Figures 3 and 8, the lower end surface of the inner shell 70 extends along the upper edge of the seat 3, leaving a gap between it and the upper edge of the seat 3 in both the side view and the front view. Also, as shown in Figure 6, the upper end surface of the outer plate 81 curves upward as it is directed towards the rear. The upper end surface of the outer plate 81 smoothly connects with the left-right outer end surfaces of the shell body 75.

[0060] The bulge portion 82 bulges inward in the left-right direction at the front end of the outer plate 81. The lower end surface of the bulge portion 82 is flush with the lower end surface of the outer plate 81. The bulge portion 82 has a base surface 82a located below the upper end surface of the outer plate 81. The base surface 82a is a flat surface extending in the front-rear direction.

[0061] As shown in Figures 5, 8, and 9, the shell projection 76 has a receiving recess 76a that opens downward. The receiving recess 76a is a recess formed to conform to the outer shape of the connecting rod 67. The receiving recess 76a is formed spanning the outer plate 81 and the bulging portion 82. The connecting rod 67 is housed in the receiving recess 76a from below. The upper end surface of the connecting rod 67 abuts against the top surface of the inner surface of the receiving recess 76a, thereby positioning the inner shell 70 in the vertical direction relative to the upright member 60. When the connecting rod 67 is housed in the receiving recess 76a, the portion of the lower end surface of the shell projection 76 that overlaps with the vertical rod 66 in a plan view is close to or in contact with the stepped surface 66a. On the other hand, the portion of the lower end surface of the shell projection 76 that does not overlap with the vertical rod portion 66 in a plan view is located below the lower end surface of the connecting rod portion 67.

[0062] The connecting portion 62 is for connecting the upright member 60 and the inner shell 70 between the connecting rod portion 67 and the shell projection portion 76. The connecting portion 62 includes a mounting seat 85 and a fastening member 86. The mounting base 85 is a plate made of metal or the like. The mounting base 85 is positioned on the base surface 82a. The mounting base 85 may be fixed to the bulging portion 82 by screws 87 (see Figure 9) or the like.

[0063] The fastening member 86 connects the bulging portion 82 and the connecting rod portion 67 with the mounting seat 85 in between. The fastening member 86 is, for example, a bolt 86a and a nut 86b. The fastening member 86 connects the bulging portion 82 and the connecting rod portion 67 by tightening a nut 86b from above onto the mounting seat 85 with a bolt 86a that penetrates the connecting rod portion 67, the bulging portion 82, and the mounting seat 85 from below. In other words, the fastening member 86 connects the upright member 60 and the inner shell 70 above the seat 3. In this embodiment, multiple fastening members 86 (for example, two) are provided at intervals in the front-rear direction. The head of the bolt 86a is housed in a recess that opens onto the lower end surface of the connecting rod portion 67, and is therefore located above the lower end surface of the connecting rod portion 67. Furthermore, the shaft portion of the bolt 86a and the nut 86b are covered from the outside in the left-right direction by the outer plate 81 above the bulging portion 82.

[0064] The exterior material 71 comprises a cushioning material 91 and a surface material 92. The cushioning material 91 mainly covers the inner surface (front and inward-facing surfaces in the left and right directions) and the upper end surface of the inner shell 70. In this case, the cushioning material 91 is also housed within the stepped portion 93 surrounded by the outer plate 81 and the bulging portion 82, thereby covering the mounting seat 85 and the fastening member 86 (the shaft portion of the bolt 86a and the nut 86b). In other words, the exterior material 71 collectively covers at least a portion of the inner shell 70 and the connecting portion 62.

[0065] The outer material 92 covers the cushioning material 91 and the inner shell 70 together. Specifically, the outer material 92 is provided so as to overlap the inner shell 70 from above. As a result, the cushioning material 91 and the inner shell 70 are covered by the outer material 92 from both sides in the front-to-back direction, both sides in the left-to-right direction, and from above. At its lower end, the outer material 92 is fixed to the lower end surface of the inner shell 70 or the inner surface of the housing recess 76a by staples T (see Figures 5 and 9). In this case, the fixing portion (staples T) between the outer material 92 and the inner shell 70 is provided within the housing recess 76a, and the connecting rod portion 67 is housed within the housing recess 76a, so it is not exposed to the outside of the chair 1. Furthermore, by housing the connecting rod portion 67 within the housing recess 76a, its periphery (at least above and on both the front, back, left, and right sides) is surrounded by the shell projection portion 76. Furthermore, since the shell projection 76 is surrounded by the surface material 92, the connecting rod 67 is also surrounded by the surface material 92.

[0066] In the superstructure 4, the shell projection 76 of the backrest body 61, the connecting rod 67, and the portion of the exterior material 71 that covers the shell projection 76 constitute the armrest 100. In this case, the portion of the exterior material 71 that constitutes the upper surface of the armrest 100 functions as an elbow support surface 100a that supports the elbow of the seated person. In the superstructure 4, the shell body 75 of the backrest body 61 and the portion of the exterior material 71 that covers the shell body 75 constitute the backrest 101. In this case, the portion of the exterior material 71 that constitutes the front of the backrest 101 functions as a backrest surface 101a that supports the back of the seated person. In this embodiment, the backrest 100 is connected to the upright member 60 via the armrest 101. That is, the seating load acting on the superstructure 4 is transmitted to the support base 12 via the upright member 60.

[0067] <Operation section 5> As shown in Figures 2, 4, and 5, the operating unit 5 is for operating the gas spring 18 via the linkage mechanism 23. The operating unit 5 is provided on the underside of the seat 3 via a lever stay 110. The lever stay 110 is a fixing fitting for fixing the operating unit 5 to the seat 3. As shown in Figure 4, the lever stay 110 is fixed to the right end of the seat receiving plate 41, in a portion located behind the upright member 60. Specifically, the left inner end (left end) of the lever stay 110 is fixed to the portion of the seat receiving plate 41 that is located inward in the left-right direction from the outer peripheral recess 50c in a plan view. That is, the lever stay 110 is fixed to the seat 3 at its exposed portion 55. The operating unit of this embodiment is composed of the operating unit 5 and the lever stay 110.

[0068] A portion of the lever stay 110 protrudes outward (to the right) in the left-right direction from the seat plate 41. Specifically, the left-right outer end of the lever stay 110 protrudes outward in the left-right direction relative to the seat plate 41. Therefore, the left-right outer end of the lever stay 110 faces the surface material 52 (exterior component 52b) in the vertical direction.

[0069] The operating part 5 is a lever. The operating part 5 is located on the underside of the seat 3, in a side view, behind the horizontal rod 65 and the vertical rod 66, and in front of the leg column 16. Therefore, the operating part 5 is located in front of the rear end of the support base 12. Alternatively, the operating part 5 is located on the underside of the seat 3, in a plan view, to the right of the center in the left-right direction. In this case, in a plan view, the operating part 5 is located in a position shifted to the right of the support base 12, and the entire unit overlaps the seat 3.

[0070] The operating unit 5 comprises a base member 120 and an operating element 121. The base member 120 is fixed to the portion of the lever stay 110 that protrudes from the seat support plate 41. That is, the operating part 5 overlaps with the seat body 39 (surface material 52) in a plan view in the portion located outward in the left-right direction from the seat support member 38. The base member 120 extends in the front-rear direction along the right edge of the seat support plate 41. As shown in Figure 5, the upper surface of the base member 120 is formed as an inclined surface that extends upward as it goes outward in the left-right direction, following the lower surface of the seat body 39.

[0071] The control element 121 is the part operated by the seated person or the like when raising or lowering the seat 3. The control element 121 is positioned below the base member 120, overlapping at least a portion of the base member 120 in the vertical direction. In a plan view, the control element 121 is formed in a fan shape, with its width gradually increasing in the left-right direction towards the rear. At its front end, the control element 121 is supported by the base member 120 so as to be rotatable around an operating axis O that runs along the vertical direction.

[0072] In the cross-sectional view perpendicular to the front-to-back direction shown in Figure 5, the operator 121 is formed in a stepped shape, with the vertical dimension gradually increasing as it moves outward in the left-to-right direction. The connecting surface of the upper and middle sections of the operator 121 constitutes a first handle portion 121a facing inward in the left-to-right direction. The connecting surface of the middle and lower sections of the operator 121 constitutes a second handle portion 121b facing inward in the left-to-right direction. Each handle portion 121a, 121b is a part on which the fingers of a seated person or the like can be hooked when operating the operator 121. In this embodiment, the handle portions 121a, 121b protrude outward in the left-to-right direction relative to the seat support plate 41 and overlap with the surface material 52 (exterior component 52b) in a plan view.

[0073] The operator 121 is connected to the linkage mechanism 23 via a wire W shown in Figures 3 and 4. The operation unit 5 operates the linkage mechanism 23 when the wire W is displaced by the rotation of the operator 121 around the operating axis O. Of the exterior components 52b, the part located outward in the left-right direction relative to the operator 121 extends upward toward the outer edge of the seat body 39. In this case, the part of the exterior components 52b located outward in the left-right direction relative to the operator 121 guides the seated person's hand to the operator 121 and functions as a hand support surface 151 on which the hand is placed when the operator 121 is operated. Note that "placed on" does not only mean contact with the hand support surface 151, but also includes facing the hand support surface 151 in close proximity.

[0074] <Height adjustment of seat 3> When raising or lowering the seat 3, the occupant inserts their hand from above the armrest 100, through the left and right outer side of the upright member 60, and under the seat 3. In this position, they hook their fingers into either the handgrip portion 121a or 121b and pull the operator 121 outwards in the left and right direction. As a result, the operator 121 rotates outwards in the left and right direction around the operating axis O from its initial position, which activates the linkage mechanism 23 via the wire W. Consequently, the operating pin 18b is pushed in via the linkage mechanism 23, enabling the gas spring 18 to extend and retract.

[0075] In other words, the seat 3 can be raised and lowered by rotating the operator 121. Specifically, by applying a load to the seat 3 that is greater than the biasing force of the gas spring 18, the gas spring 18 compresses and the seat 3 descends. On the other hand, if the load applied to the seat 3 is less than the biasing force of the gas spring 18, the gas spring 18 extends and the seat 3 rises. When the operator 121 is released, the operator 121 returns to its initial position due to the biasing force of a biasing member (not shown) interposed between the operator 121 and the base member 120. This releases the pushing operation of the operating pin 18b by the linkage mechanism 23. As a result, the extension and retraction movement of the gas spring 18 is restricted.

[0076] <Reclining motion of seat 3> Figure 11 is a cross-sectional view of chair 1 in the reclined position. In Figure 11, the dashed line indicates the initial state (before reclining) of the seat 3 and upper structure 4. As shown in Figures 3 and 11, when a person sits on the seat 3 of the chair 1 in its initial state and leans against the backrest 101 via the backrest surface 101a, the seating load acting on the backrest 101 is transmitted to the front link 25 via the upright member 60. As a result, the front link 25 rotates around the main axis C1, causing the entire upper structure 4 to rotate backward and downward.

[0077] As the front link 25 rotates around the main axis C1, the seat support axis C3 revolves around the main axis C1, causing the front end of the seat 3 to rotate backward and upward. Meanwhile, the seat 3 is connected to the base 12 via the rear link 26 at its center in the front-rear direction. Therefore, in accordance with the displacement of the front end of the seat 3, the rear link 26 rotates so that the upper axis C4 revolves around the lower axis C2. Consequently, in accordance with the displacement of the front end of the seat 3, the rear end of the seat 3 rotates backward and downward. In other words, in the chair 1 of this embodiment, the seat 3 is displaced backward and downward in accordance with the reclining operation of the upper structure 4.

[0078] In this embodiment, the distance between the lower axis C2 and the upper axis C4 is shorter than the distance between the main axis C1 and the seat support axis C3. Therefore, the amount of rotation of the seat 3 around the main axis C1 is smaller than the amount of rotation of the upper structure 4 around the main axis C1.

[0079] Reference numeral 125 in Figure 11 indicates a reaction spring mechanism that biases the seat 3 and the upper structure 4 to their initial state via the front link 25. The reaction spring mechanism 125 is interposed between the support wall 24 and the front link 25. That is, when the seating load acting on the backrest 101 is released, for example, when the seated person moves away from the backrest surface 101a, the front link 25 rotates around the main axis C1 due to the biasing force of the reaction spring mechanism 125. This returns the upper structure 4 and the seat 3 to their initial state. The chair 1 may also be equipped with a tilting operation unit that switches between a locked state that restricts the rotation of the upper structure 4 and the seat 3 via the tilting mechanism 22, and an unlocked state that allows the rotation of the upper structure 4 and the seat 3.

[0080] The chair 1 of this embodiment comprises a box-shaped support base (support mechanism) 12, a seat 3 having an upward-facing seating surface 3a and connected to the front of the support base 12, and supported from below by the support base 12 such that there is a vertical gap between the seat 3 and the rear of the support base 12, and a superstructure (load support part) 4 that supports the weight of the sitter above the seat 3, having a pair of upright members 60 that extend outward in the left-right direction relative to the seat 3, straddling the seat 3 vertically in a side view, and connected to the front end of the support base 12 below the seat 3. The chair 1 is equipped with an operating part 5 that is connected to a linkage mechanism (operation mechanism) 23 of the chair 1 and operates a gas spring 18 via the linkage mechanism 23. The operating part 5 is located on the part of the seat 3 that is behind the upright members 60 and in front of the rear end of the support base 12. With this configuration, the operating unit 5 is located in the part of the seat 3 that is behind the upright member 60 and in front of the rear end of the support base 12. Compared to the conventional case where the operating unit 5 is located coaxially with the main axis C1 at the connection point between the upright member 60 and the support base 12, the layout flexibility for the operating unit 5 and the upright member 60 can be improved. Furthermore, compared to the conventional case where the operating unit 5 is located coaxially with the main axis C1 at the connection point between the upright member 60 and the support base 12, the enlargement of the connection point (the connection point between the horizontal rod 65 and the front link 25) can be suppressed. Furthermore, since at least a portion of the operating section 5 is positioned so as not to overlap with the upright member 60 in a side view, there is no need to insert a hand or the like between the upright member 60 and the seat 3 to operate the operating section 5. Therefore, operability can be improved.

[0081] In the chair 1 of this embodiment, the seat 3 is supported on the front of the base 12 so as to be rotatable around a seat support axis (first axis) C3 that runs in the left-right direction, and the operating unit 5 is positioned on the seat 3 at a location offset from the base 12 in the left-right direction when viewed from above. With this configuration, the operating unit 5 is positioned offset from the base 12 in a plan view, thus avoiding interference between the operating unit 5 and the base 12 when the seat 3 is rotated.

[0082] In the chair 1 of this embodiment, the upright member 60 is supported at the front of the base 12 so as to be rotatable around the main axis (second axis) C1 that runs in the left-right direction, and the operating part 5 is attached to the underside of the seat 3. With this configuration, interference between the operating unit 5 and the upright member 60 can be avoided when the upright member 60 rotates around the main axis C1.

[0083] In the chair 1 of this embodiment, a tilting mechanism 22 is provided that links the rotation of the seat 3 and the upright member 60 such that the amount of rotation of the seat 3 around the seat support axis C3 is smaller than the amount of rotation of the upright member 60 around the main axis C1. With this configuration, the amount of rotation of the seat 3 around the seat support axis C3 is smaller than the amount of rotation of the upright member 60 around the main axis C1, thus reducing the feeling of the seat 3 sinking when the upper structure 4 rotates (reclines). This provides a good seating experience for the occupant. On the other hand, as the tilting mechanism 22 operates, the amount of rotation of the seat 3 around the seat support axis C3 becomes smaller than the amount of rotation of the upright member 60 around the main axis C1, and as the upright member 60 rotates, the distance between the upright member 60 and the operating unit 5 around the main axis C1 in a side view becomes narrower. However, in this embodiment, since the operating unit 5 is provided on the underside of the seat 3, interference between the operating unit 5 and the upright member 60 can be avoided even when the amount of rotation of the seat 3 around the seat support axis C3 is smaller than the amount of rotation of the upright member 60 around the main axis C1. In particular, in this embodiment, since the upright member 60 (vertical rod portion 66) is positioned in front of the backrest 101 (closer to the main axis C1), the amount of rotation of the upright member 60 around the main axis C1 is smaller than the amount of rotation of the backrest 101 around the main axis C1. Therefore, interference between the upright member 60 and the operating part 5 is easily avoided when the upper structure 4 rotates.

[0084] In the chair 1 of this embodiment, the operating section 5 is equipped with an operating element 121 that is rotatable around an operating axis (third axis) O that runs in the vertical direction. According to this embodiment, the operator 121 is easier to operate when a hand is inserted into the space below the seat 3 from the side of the seat 3.

[0085] In the chair 1 of this embodiment, the operator 121 is displaceable outward in the left-right direction around the operating axis O from its initial position. According to this embodiment, the operator 121 is easier to operate when a hand is inserted into the space below the seat 3 from the side of the seat 3.

[0086] In the chair 1 of this embodiment, the operating unit 5 is provided between the seat 3 and the base 12 in the vertical direction. According to this embodiment, compared to a configuration in which, for example, the operating unit 5 protrudes downward from the base 12 or protrudes upward from the seat 3, the impact of the operating unit 5 on the appearance of the chair 1 can be reduced.

[0087] In the chair 1 of this embodiment, a leg column 16 extends downward from the rear end of the support base 12, and the operating mechanism includes a gas spring (lifting mechanism) 18 of the chair 1 that extends and retracts the leg column 16 in the vertical direction, and the operating unit 5 is provided in front of the leg column 16. According to this embodiment, even though the operating section 5 is located behind the upright member 60, it is possible to position the operating section 5 in a location that is easily accessible to the seated person when they lower their hands. Furthermore, it is possible to prevent the operating section 5 from being located in the gap between the rear of the seat 3 and the rear of the support base 12. This makes it easier to secure a gap between the rear of the seat 3 and the rear of the support base 12. As a result, it is possible to provide a chair 1 that has the appearance of the seat 3 extending backward from the support base 12 in a cantilevered manner.

[0088] (Second Embodiment) Figure 12 is a rear view of the area around the seat 3 in the chair 1 according to the second embodiment. Figures 13 and 14 are exploded perspective views of the seat 3 viewed from below in the chair 1 according to the second embodiment. In the chair 1 shown in Figures 12 to 14, a first operating unit 200 and a second operating unit 201 are provided below the seat 3.

[0089] <First operating unit 200> Figure 15 is a cross-sectional view corresponding to the line XV-XV in Figure 13. As shown in Figures 13 and 15, the first operating unit 200 is for operating the linkage mechanism 23, similar to the operating unit in the first embodiment. The first operating unit 200 is located below the seat 3 and to the right of the support base 12. The first operating unit 200 comprises a first lever stay 210 and a first operating section 211.

[0090] The first lever stay 210 is fixed to the exposed portion 55 from below and extends cantilevered outward (to the right) in the left-right direction. The first lever stay 210 extends in the left-right direction while bending in the up-down direction. Specifically, the first lever stay 210 comprises a first fixing piece 210a, a first connecting piece 210b, and a first protruding piece 210c. The first fixing piece 210a is positioned below the seat 3, with the vertical direction being the thickness direction. The first fixing piece 210a is positioned so as to overlap with the exposed portion 55 (seat receiving plate 41) in a plan view. Specifically, the first fixing piece 210a is fixed to the portion of the seat receiving plate 41 that is located inward in the left-right direction from the outer peripheral recess 50c using screws B1. The first connecting piece 210b is the portion that connects the first fixing piece 210a and the first protruding piece 210c. The first connecting piece 210b extends from the first fixing piece 210a in a manner that is inclined downward as it extends outward in the left-right direction. The first connecting piece 210b is positioned so as to straddle the outer peripheral recess 50c in the left-right direction.

[0091] The first protruding piece 210c extends outward from the first connecting piece 210b in the left-right direction. Specifically, the first protruding piece 210c faces the exterior component 52b (outer part 50b) with a gap in the vertical direction. Following the exterior component 52b, the first protruding piece 210c extends in an upward inclination as it extends outward in the left-right direction.

[0092] The first operating section 211 is rotatably supported on the first protruding piece 210c. The first operating section 211 comprises a first operating base 211a and a handle 211b. The first operating base 211a is formed in a fan shape in a plan view, with its width gradually increasing in the left-right direction as it extends towards the rear. In a cross-sectional view along the left-right direction, the first operating base 211a extends in accordance with the exterior component 52b. Specifically, the first operating base 211a extends in an upward inclination as it extends outward in the left-right direction. At its front end, the first operating base 211a is supported by the first projection piece 210c so as to be rotatable around the operating axis O. In this embodiment, the operating axis O coincides with the thickness direction of the first projection piece 210c. That is, the operating axis O extends in an outward inclination in the left-right direction as it extends downward.

[0093] The handgrip portion 211b is formed along the left-right outer edge of the first operating base 211a. The handgrip portion 211b protrudes downward from the first operating base 211a. The inner surface of the handgrip portion 211b in the left-right direction functions as a handgrip surface 211b1 that receives the force exerted by the seated person when they place their fingers on it and try to move the entire first operating portion 211 outward in the left-right direction.

[0094] The first operating unit 211 is configured to be rotatable about the operating axis O within a first virtual plane Q1 that is perpendicular to the operating axis O. The first virtual plane Q1 is positioned to intersect with the horizontal plane. By rotating about the operating axis O, the first operating unit 211 is displaced between an initial position P11 and an operating position P12. By displacing the first operating unit 211 outward in the left-right direction from the initial position P11 towards the operating position P12, the linkage mechanism 23 is operated via the wire W. In this embodiment, since the outer casing component 52b (outer part 50b) is formed in an arc shape, the vertical distance between the first operating unit 211 and the outer casing component 52b increases as the amount of rotation (movement) of the first operating unit 211 from the initial position P11 increases. Furthermore, in a cross-sectional view along the left-right direction, if the exterior component 52b is formed on an inclined surface with a uniform angle with respect to the horizontal plane, the angle between the first virtual plane Q1 and the horizontal plane may be made smaller than the angle of the exterior component 52b. Even in this case, as the amount of rotation (movement) of the first operating unit 211 from its initial position P11 increases, the vertical distance between the first operating unit 211 and the exterior component 52b increases.

[0095] The first operating section 211 is biased toward the initial position P11 by a biasing member (not shown). Furthermore, the first operating section 211 is restricted from moving inward in the left-right direction relative to the initial position P11 by a stopper piece 210d formed at the boundary between the first connecting piece 210b and the first protruding piece 210c.

[0096] The first operating unit 211 is positioned so as to overlap with the seat 3 in a plan view at both the initial position P11 and the operating position P12. However, the first operating unit 211 may be positioned so as to overlap with the seat 3 in a plan view at least at the initial position P11.

[0097] Here, at least a portion of the first operating section 211 faces the exterior component 52b in the vertical direction at the initial position P11. Specifically, the portion of the first operating base 211a located on the inside in the left-right direction faces the exterior component 52b with the first protruding piece 210c in between. Of the first operating section 211, the left-right outer end of the first operating base 211a and the handle portion 211b face the exterior component 52b on the left-right outer side relative to the first protruding piece 210c. It is preferable that, for at least the portion of the seat body 39 facing the handle portion 211b, an outer peripheral cushion portion 51b is interposed between the exterior component 52b and the outer portion 50b. Furthermore, it is preferable that the seat body 39 (exterior component 52b) and the first operating section 211 (handle portion 211b) are close together with a gap (for example, about 5 mm) that prevents fingers or the like from entering.

[0098] The portion of the right side of the seat 3 (exterior component 52b) that is located outward in the left-right direction relative to the first operating section 211 and extends to the outer edge of the seat body 39 functions as the first hand support surface 250a. The first hand support surface 250a guides the seated person's hand to the first operating section 211 and is the part on which the hand is placed when operating the first operating section 211. For example, the seated person can operate the first operating section 211 outward in the left-right direction by placing their hand on the first hand support surface 250a, extending their fingers inward in the left-right direction, and placing their fingers on the handgrip surface 211b1 of the handgrip section 211b.

[0099] <Second operating unit 201> As shown in Figure 13, the second operating unit 201 is for operating the tilting operating unit (not shown) described above. The tilting operating unit switches between a locked state that restricts the rotation of the upper structure 4 and the seat 3 via the tilting mechanism 22, and an unlocked state that allows the rotation of the upper structure 4 and the seat 3. The second operating unit 201 is located below the seat 3, to the left of the support base 12. The second operating unit 201 is also located in the same position as the first operating unit 200 in the front-rear direction (overlapping in a side view). However, the first operating unit 200 and the second operating unit 201 may be located in different positions in the front-rear direction, or they may be located on the same side of the support base 12.

[0100] The second operating unit 201 comprises a second lever stay 220 and a second operating section 221.

[0101] Figure 16 is a cross-sectional view corresponding to the line XVI-XVI in Figure 14. As shown in Figure 16, the second lever stay 220 is fixed to the exposed portion 55 from below and extends cantilevered outward (to the left) in the left-right direction. The second lever stay 220 comprises a stay base 225 and a movable support portion 226. The stay base 225 extends in the left-right direction while bending in the vertical direction. Specifically, the stay base 225 comprises a second fixing piece 225a, a second connecting piece 225b, and a second protruding piece 225c.

[0102] The second fixing piece 225a is positioned below the seat 3, with the vertical direction being the thickness direction. The second fixing piece 225a is positioned so as to overlap with the exposed portion 55 of the seat 3 in a plan view. The outer end of the second fixing piece 225a in the left-right direction overlaps with the outer peripheral recess 50c in a plan view. The second connecting piece 225b is the portion that connects the second fixing piece 225a and the second protruding piece 225c. The second connecting piece 225b extends from the second fixing piece 225a in a manner that is inclined downward as it extends outward in the left-right direction. The second connecting piece 225b is positioned to straddle the outer peripheral recess 50c in the left-right direction. The second protruding piece 225c extends outward from the second connecting piece 225b in the left-right direction. Specifically, the second protruding piece 225c faces the exterior component 52b and extends in a manner that is inclined upward as it extends outward in the left-right direction, following the example of the exterior component 52b.

[0103] The movable support portion 226 is provided below the stay base 225, overlapping it vertically with the stay base 225. The movable support portion 226 is formed in a box shape that opens upward. The movable support portion 226 extends horizontally while bending vertically, following the shape of the stay base 225. The movable support portion 226 includes a wire holding portion 226a and a guide portion 226b.

[0104] Figure 17 is a cross-sectional view corresponding to the line XVII-XVII in Figure 14. As shown in Figures 16 and 17, the wire holding portion 226a overlaps with the second fixing piece 225a and the second connecting piece 225b of the movable support portion 226 in a plan view. The second lever stay 220 is fixed to the seat plate 41 by screws B2 that pass through the wire holding portion 226a and the second fixing piece 225a. That is, the second lever stay 220 is fixed to the seat 3 (seat plate 41) at a position that overlaps with the exposed portion 55 in a plan view.

[0105] As shown in Figure 16, a wire retaining groove 228 is formed in the central part of the wire retaining portion 226a in the front-to-back direction. The wire retaining groove 228 extends in the left-to-right direction within the wire retaining portion 226a. The wire W2 is routed through the wire retaining groove 228 within the wire retaining portion 226a in the left-to-right direction.

[0106] As shown in Figures 14 and 17, the guide portion 226b extends outward from the wire holding portion 226a in the left-right direction. The guide portion 226b comprises a guide base 230, a locking claw 231, and a pair of stopper portions 232. The guide base 230 forms the outer shape of the guide portion 226b. The guide base 230 is positioned facing the second projection piece 225c in the vertical direction. The guide base 230 extends in an upward inclination as it moves outward in the left-right direction.

[0107] The locking claws 231 protrude upward from the left-right outer ends of the guide base 230. The locking claws 231 are hooked onto the second protruding piece 225c. A pair of locking claws 231 are provided at both ends of the guide base 230 in the front-rear direction.

[0108] A pair of stopper portions 232 are provided at both ends of the guide base 230 in the front-rear direction. Each stopper portion 232 has the same configuration. Therefore, in the following description, the details of the stopper portion 232 will be explained using one of the stopper portions 232 as an example. The stopper portion 232 is a leaf spring shape formed integrally with the guide base 230. As shown in Figure 17, the stopper portion 232 is formed to bridge the opposing edges of the through hole 230a formed in the guide base 230 in the left-right direction. The central part of the stopper portion 232 in the left-right direction constitutes an elastic projection 232a that protrudes downward from the through hole 230a. The elastic projection 232a is elastically displaced vertically as the stopper portion 232 undergoes elastic deformation.

[0109] Figure 18 is a cross-sectional view corresponding to line XVIII-XVIII in Figure 14. As shown in Figure 18, guide grooves 220a are formed at both ends of the second lever stay 220 in the front-rear direction. The guide grooves 220a are gaps formed between the second protruding piece 225c and the bottom wall of the movable support portion 226. The guide grooves 220a open outward in the front-rear direction and extend in accordance with the second protruding piece 225c. That is, the guide grooves 220a extend in an upward inclination as they move outward in the left-right direction.

[0110] As shown in Figures 14 and 16, the second operating section 221 is slidably supported on the second lever stay 220. The second operating section 221 comprises a second operating base 221a, a guide rail 221b, a wire locking section 221c, and a handgrip section 221d.

[0111] The second operating base 221a is formed in a box shape that is open upwards. The second operating base 221a is mounted on the guide portion 226b of the second lever stay 220 so as to overlap it from below. The second operating base 221a is mounted on the second lever stay 220 in a state inclined so as to extend upward as it moves outward in the left-right direction. The second operating portion 221 faces the exterior component 52b, protruding outward in the left-right direction from the exposed portion 55. Note that at least a portion of the second operating portion 221 needs to face the exterior component 52b.

[0112] As shown in Figure 18, the guide rails 221b are provided on the portions of the second operating base 221a that are located on both the front and rear sides relative to the second lever stay 220. Each guide rail 221b is housed within its corresponding guide groove 220a. Each guide rail 221b extends in an upward inclination as it moves outward in the left-right direction, following the guide groove 220a.

[0113] Figure 19 is a cross-sectional view showing the second operating section 221 in the extended position, corresponding to Figure 17. As shown in Figures 17 and 19, the second operating part 221 is configured to slide relative to the second lever stay 220 within a second virtual plane Q2 along the extending direction of the guide groove 220a. The second virtual plane Q2 is positioned intersecting the horizontal plane. The tilting operating part is operated via the wire W2 by the displacement of the second operating part 221 along the second virtual plane Q2 between an initial position P21 and an extended position P22. Specifically, the tilting operating part allows the reclining movement of the superstructure 4 when the second operating part 221 is in the initial position P21, and restricts the reclining movement of the superstructure 4 when the second operating part 221 is in the extended position P22.

[0114] In this embodiment, since the exterior component 52b (outer part 50b) is formed in an arc shape, the vertical distance between the second operating unit 221 and the exterior component 52b increases as the amount of movement of the second operating unit 221 from its initial position P21 increases. Note that if the exterior component 52b is formed on an inclined surface with a uniform angle to the horizontal plane in a cross-sectional view along the left-right direction, the angle between the second virtual plane Q2 and the horizontal plane may be made smaller than the angle of the exterior component 52b. Even in this case, the vertical distance between the second operating unit 221 and the exterior component 52b increases as the amount of movement of the second operating unit 221 from its initial position P21 increases.

[0115] The second operating section 221 is positioned so as to overlap with the seat 3 in a plan view, both in the initial position P21 and the extended position P22. However, the second operating section 221 may be positioned so as to overlap with the seat 3 in a plan view, at least in the initial position P21.

[0116] As shown in Figures 16 and 18, the wire locking portion 221c protrudes upward from the bottom wall of the guide rail 221b. The end of the wire W2 that has passed through the wire holding portion 226a is hooked onto the wire locking portion 221c.

[0117] As shown in Figures 17 and 19, a first recess 240 and a second recess 241 are formed in the bottom wall of the guide rail 221b at positions that overlap with each stopper portion 232 in a plan view. The first recess 240 and the second recess 241 are formed in the bottom wall of the guide rail 221b with an upward opening. The first recess 240 is located outward in the left-right direction relative to the second recess 241. The elastic projection 232a fits into the first recess 240 when the second operating portion 221 is in its initial position P21. On the other hand, the elastic projection 232a fits into the second recess 241 when the second operating portion 221 is in its extended position P22. The second operating portion 221 is biased toward the initial position P21 by a biasing member (not shown). In the initial position P11, the second operating portion 221 is restricted from moving inward in the left-right direction relative to the initial position P11 by the elastic projection 232a fitting into the first recess 240.

[0118] The handle portion 221d extends downward from the left-right outer end of the second operating base 221a. At least a portion of the second operating portion 221 faces the exterior component 52b in the vertical direction in the initial position P21. Specifically, the entire handle portion 221d faces the exterior component 52b with the second lever stay 220 in between. It is preferable that, for at least the portion of the seat body 39 that faces the handle portion 221d, an outer peripheral cushion portion 51b is interposed between the exterior component 52b and the outer portion 50b. It is also preferable that the seat body 39 (exterior component 52b) and the second operating portion 221 (handle portion 221d) are close together with a gap (for example, about 5 mm) that prevents fingers or other objects from entering. The surface of the handgrip portion 221d that faces inward in the left-right direction, with the maximum downward projection as the boundary, functions as a handgrip surface 221d1 that receives the force exerted by the seated person when they place their fingers on it and try to move the entire second operating portion 221 outward in the left-right direction.

[0119] The portion of the left side of the seat 3 (exterior component 52b) that is located outward in the left-right direction relative to the second operating section 221 and extends to the outer edge of the seat body 39 functions as the second hand support surface 250b. The second hand support surface 250b guides the seated person's hand to the second operating section 221 and is the part on which the hand is supported when operating the second operating section 221.

[0120] To move the tilting mechanism to the locked position, the upper structure 4 is set to its initial position, and the second operating mechanism 221 is operated. Specifically, the seated person inserts their hand from above the armrest 100, through the left and right outer side of the upright member 60, and under the seat 3. At this time, after the hand passes the seating surface 3a, the hand is wrapped around the seat 3 (exterior component 52b) along the second hand support surface 250b (left side) to the underside of the seat 3. Then the hand reaches the second operating mechanism 221. In this state, the finger is hooked onto the hand grip surface 221d1 of the hand grip 221d, and the second operating mechanism 221 is pulled outwards in the left and right direction. At this time, the second operating mechanism 211 is pulled outwards while supporting the second hand support surface 250b with the hand.

[0121] When the second operating section 221 is pulled outward, it slides outward from its initial position P21 in the left-right direction. During this process, the second operating section 221 moves along the second hand support surface 250b by moving within the plane of the second virtual surface Q2. This pulls the wire W2, causing the tilting operating section to operate. When the second operating section 221 reaches the pulled-out position P22, the tilting operating section locks into place. That is, the tilting operating section enters the operating trajectory of the tilting mechanism 22 and restricts the rotation of the upper structure 4 and seat 3 via the tilting mechanism 22. The second operating section 221 is box-shaped with an upward opening, and the second operating base 221a overlaps the guide portion 226b of the second lever stay 220 from below. In other words, the guide section 226b is housed in the internal space of the second operating section 221, but because the second operating section 221 moves along the second hand support surface 250b, the guide section 226b, the adjacent wire locking section 221c, and the wire holding section 226a are difficult to see from above.

[0122] As described above, the chair 1 of this embodiment includes a seat 3 having a core member 150 (seat support plate 41, seat shell 50, and cushioning material 51) and a surface material 52 covering the core member 150, and operating units 200, 201 for operating the chair 1's operating mechanism (linking mechanism 23 and tilting operation part). The core member 150 includes an upper surface portion (main cushion portion 51a) that constitutes the seating surface 3a of the seat 3, and an outer surface portion including an outer surface (outer part 50b) extending downward from both left and right edges of the upper surface portion and a lower surface (seat support plate 41) connected to the lower end of the outer surface. The surface material 52 has a peripheral edge portion in the part facing the outer part 50b. Each operating unit 200, 201 includes lever stays (fixing members) 210, 220 provided on the exposed portion 55 of the core member 150 that is not covered by the outer material 52, and operating parts 211, 221 that are supported so as to be movable relative to the lever stays 210, 220 and are connected to the operating mechanism. At least a portion of the operating parts 211, 221 is located outward in the left-right direction relative to the exposed portion 55, and faces in the up-down direction relative to the portion of the outer material 52 that covers the outer surface (exterior component 52b). With this configuration, the lever stays 210 and 220 are fixed to the portion of the core member 150 that is not covered by the outer material 52 (exposed portion 55), so that the lever stays 210 and 220 can be attached to the core member 150 without forming any openings in the outer material 52. Furthermore, since at least a portion of the operating parts 211 and 221 are positioned outward in the left-right direction relative to the exposed portion 55 and facing the exterior component 52b in the vertical direction, it is easy to position the operating parts 211 and 221 within reach of the seated person. As a result, the operability of the control units 211 and 221 can be maintained while improving the design and durability of the seat 3.

[0123] In the chair 1 of this embodiment, the outer surface of the core member 150 is an inclined surface that extends outward in the left-right direction as it goes upward. The operating parts 211 and 221 face each other in the vertical direction relative to the inclined surface. With this configuration, the seated person can reach the operating sections 211 and 221 by extending their hand along the outer surface (hand support surface 250a, 250b) of the core member 150. In this case, access to the operating sections 211 and 221 is easier compared to, for example, the case where the outer surface of the core member 150 is formed perpendicular to the horizontal plane. As a result, further improvements in operability can be achieved.

[0124] In the chair 1 of this embodiment, the operating parts 211 and 221 are movable outward in the left-right direction from their initial positions P11 and P21 on virtual planes Q1 and Q2 which are inclined upward with respect to the horizontal plane. The vertical distance between the operating parts 211 and 221 and the outer surface increases as the amount of movement of the operating parts 211 and 221 from their initial positions P11 and P21 increases. This configuration suppresses interference between the surface material 52 and the operating parts 211 and 221 when the operating parts 211 and 221 are moved. This suppresses damage to the surface material 52 and improves the durability of the seat 3.

[0125] In the chair 1 of this embodiment, an outer peripheral cushion portion (cushioning material) 51b is interposed between the outer surface portion and the surface material 52 (exterior component portion 52b). This configuration allows for the mitigation of impacts and other shocks that may occur when hands touch the seat 3 during operation of the control units 211 and 221. This improves the operability of the control units 211 and 221.

[0126] In the chair 1 of this embodiment, the lever stays 210 and 220 extend outward in the left-right direction from the exposed portion 55 and are provided with protruding pieces (outer ends) 210c and 225c that face each other in the vertical direction relative to the exterior component 52b. This configuration makes it easier to position the lever stays 210 and 220 on the outside in the left-right direction, while setting the peripheral edge of the surface material 52 on the inside of the outer surface. This improves the aesthetic appeal and durability of the seat 3 while maintaining the operability of the operating parts 211 and 221.

[0127] In the chair 1 of this embodiment, the surface material 52 covers the upper surface from above and also covers a part of the outer surface via the outer edge of the upper surface. In this configuration, the core member 150 is covered by the surface material 52 from above to the sides. Therefore, the aesthetic design of the seat 3 can be improved.

[0128] (Other variations) While preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments. Additions, omissions, substitutions, and other modifications are possible without departing from the spirit of the present invention. The present invention is not limited by the above description, but only by the appended claims. In the above-described embodiment, the upper structure 4, which serves as the load-bearing section, was described in a configuration that includes both an armrest 100 and a backrest 101, but the configuration is not limited to this. The load-bearing section only needs to include either an armrest 100 or a backrest 101. In addition, the load-bearing section may also include other components that support the weight of the occupant (for example, a headrest or lumbar support).

[0129] In the embodiments described above, the upper structure 4 was described as being reclinable, but the configuration is not limited to this. The upper structure 4 may be non-reclinable. Also, the seat 3 may not rotate. In the embodiment described above, the operating unit 5 operates the gas spring 18 for adjusting the height of the seat 3 via the linkage mechanism 23, but the configuration is not limited to this. The operating unit may also be configured to operate the tilting mechanism 22. In addition to the tilting mechanism 22 and the linkage mechanism 23, the operating unit may also operate the operating mechanisms of the chair 1 (for example, the headrest, lumbar support, casters 17, etc.).

[0130] In the embodiment described above, the operating unit 5 is attached to the lower surface of the seat 3, but the configuration is not limited to this. The operating unit 5 may be provided on the side, rear, or top surface of the seat 3. In the embodiment described above, the operating unit 5 is positioned offset from the base 12 in a plan view, but the configuration is not limited to this. The operating unit 5 may be positioned in a position that overlaps with the base 12 in a plan view. In the embodiment described above, a configuration was described in which the amount of rotation of the seat 3 is small compared to the amount of rotation of the superstructure 4, but the embodiment is not limited to this configuration. In the embodiment described above, a configuration in which the operator 121 is operated by rotation was described, but the configuration is not limited to this. The operator 121 may also be operated by sliding or pushing.

[0131] In the embodiment described above, the operating unit 5 is located in front of the leg column 16, but the configuration is not limited to this. In the embodiment described above, the operating part 5 was described as being provided between the seat 3 and the support base 12 in the vertical direction, but the configuration is not limited to this. The operating part 5 may protrude upward from the seat 3 or protrude downward from the support base 12. In the above-described embodiment, a configuration in which the upright member 60 and the inner shell 70 are formed separately was explained, but the configuration is not limited to this. The upright member 60 and the inner shell 70 may be formed integrally.

[0132] In the embodiment described above, a configuration was described in which the surface material 52 covers the seat shell 50 and the cushioning material 51, but it may also be configured to cover a part of the seat support plate 41. In other words, the surface material 52 is not limited to a configuration that covers the upper surface and outer surface of the core member 150, but may also cover the lower surface. Furthermore, the surface material 52 may cover only a portion of the outer surface if its peripheral edge is located in a position facing the outer surface. In the embodiment described above, a configuration was described in which the outer surface (outer part 50b) of the core member 150 is formed as an inclined surface, but the configuration is not limited to this. The outer surface of the core member 150 may be formed perpendicular to the horizontal plane, or it may be configured to extend in a stepped manner outward in the left-right direction as it goes upward. In the embodiment described above, the case in which the lower surface of the seat support plate 41 constitutes the lower surface of the core member 150 was explained, but the core member 150 may be configured without a seat support plate 41. In this case, the fixing member is fixed to the seat shell 50 itself. In the embodiment described above, a configuration was described in which the fixed end 52b1 is fixed to the inner surface of the outer peripheral recess 50c, but the width of the outer peripheral recess 50c can be changed as appropriate. The outer peripheral recess 50c may be, for example, a width such that the fixed end 52b1 is locked into the peripheral edge of the exterior component 52b.

[0133] In the embodiment described above, the vertical distance between the operating parts 211, 221 and the outer surface is described as increasing as the amount of movement of the operating parts 211, 221 from their initial positions P11, P21 increases, but the configuration is not limited to this. The direction of movement of the operating parts 211, 221 and the outer surface may be arranged parallel to each other. In the embodiments described above, the operating parts 211 and 221 were configured to move along the outer surface of the core member 150, but the configuration is not limited to this. The operating parts may be configured to rotate or slide in a direction approaching or moving away from the outer surface of the core member 150. Furthermore, the operating parts may be configured to move not only in the left-right direction but also in the front-back direction.

[0134] In the embodiment described above, a configuration was described in which the lever stays 210 and 220 are fixed to the lower surface (receiving plate 41) of the core member 150, but the configuration is not limited to this. The lever stays 210 and 220 may be fixed to the outer surface of the core member 150. That is, the exposed portion 55 is not limited to the lower surface of the core member 150, but may also be set on the outer surface of the core member 150. In this case, the lever stays 210 and 220 may be located below the peripheral edge of the surface material 52, for example, and at the same position as the peripheral edge of the surface material 52 in the left-right direction.

[0135] Furthermore, without departing from the spirit of the present invention, the components in the embodiments described above can be replaced with well-known components as appropriate, and the modifications described above can be combined as appropriate. [Explanation of Symbols]

[0136] 1: Chair 3: Za 3a: Seat surface 4: Upper structure (load support part) 5:Operation unit 22:Tilt mechanism (operation mechanism) 51b: Outer cushioning section (cushioning material) 52:Skin material 55:Exposed part 150: Core material 200: First operating unit 201: Second Operating Unit 210: First lever stay (fixing member) 210c: First protruding piece (outer end) 211: 1st operation section 220: Second lever stay (fixing member) 221:Second operation section 225c: Second protruding piece (outer end) P11,P21: Initial position Q1: First virtual surface (virtual surface) Q2: Second virtual surface (virtual surface)

Claims

1. A seat having a core member and a surface material covering the core member, It includes an operating unit for operating the chair's movement mechanism, The core member is The upper surface portion that constitutes the seating surface of the aforementioned seat, The upper surface portion includes an outer surface portion that includes an outer surface portion extending downward from both side edges in the left-right direction and a lower surface portion that is connected to the lower end of the outer surface portion, The surface material has a peripheral edge portion in the part facing the outer surface portion, The aforementioned operating unit is A fixing member provided on an exposed portion of the outer surface that is not covered by the surface material, It comprises an operating unit that is supported so as to be movable relative to the fixed member and connected to the operating mechanism, The chair wherein at least a portion of the operating section is located on the outside in the left-right direction relative to the exposed portion, and faces the portion of the surface material that covers the outer surface in the vertical direction.

2. The aforementioned outer surface is an inclined surface that extends outward in the left-right direction as it goes upward, The chair according to claim 1, wherein the operating section faces the inclined surface in the vertical direction.

3. The aforementioned operating unit is movable outward from its initial position in the left-right direction on a virtual plane that is inclined upward with respect to the horizontal plane. The chair according to claim 2, wherein the vertical distance between the operating part and the outer surface increases as the amount of movement of the operating part from its initial position increases.

4. The chair according to any one of claims 1 to 3, wherein a cushioning material is interposed between the outer surface and the surface material.

5. The fixing member extends outward in the left-right direction from the exposed portion and has an outer end that faces in the vertical direction with respect to the portion of the surface material that covers the outer surface portion. The chair according to any one of claims 1 to 3, wherein the operating part is supported at the outer end.

6. The chair according to any one of claims 1 to 3, wherein the surface material covers the upper surface from above and covers a part of the outer surface via the outer peripheral edge of the upper surface.

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