chair

Abstract

To provide a chair that improves operability, layout flexibility, and overall appearance. [Solution] A chair according to one aspect of the present invention comprises a box-shaped support mechanism, a seat having an upward-facing seating surface and connected to the front of the support mechanism, and supported from below by the support mechanism such that there is a vertical gap between the seat and the rear of the support mechanism, and a load-bearing part having a pair of upright members that extend outward in the left-right direction relative to the seat, straddling the seat vertically in a side view, and connected to the front end of the support mechanism below the seat, and supporting the weight of the sitter above the seat. The chair is connected to an operating mechanism and is equipped with an operating part for operating the operating mechanism. The operating part is provided on the part of the seat that is behind the upright members and in front of the rear end of the support mechanism.

Description

Technical Field

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[0001] ​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​ (1) A chair according to one aspect of the present invention comprises a box-shaped support mechanism, a seat having an upward-facing seating surface and connected to the front of the support mechanism, and supported from below by the support mechanism such that there is a vertical gap between it and the rear of the support mechanism, and a load support part having a pair of upright members that extend outward in the left-right direction relative to the seat, straddling the seat vertically in a side view, and connected to the front end of the support mechanism below the seat, and supporting the weight of the sitter above the seat, wherein the chair is connected to an operating mechanism and has an operating part for operating the operating mechanism, and the operating part is provided on the part of the seat that is located behind the upright members and in front of the rear end of the support mechanism.

[0007] According to this embodiment, since the operating section is located in the part of the seat that is behind the upright member and in front of the rear end of the support mechanism, the degree of layout freedom for the operating section and the upright member can be improved compared to the conventional case where the operating section is located in the part of the upright member that connects to the support mechanism. In addition, the size of the connection part can be suppressed compared to the conventional case where the operating section is located in the part of the upright member that connects to the support mechanism. Furthermore, since at least a portion of the control panel is positioned so as not to overlap with the upright member when viewed from the side, there is no need to insert a hand or other object between the upright member and the seat to operate the control panel. Therefore, operability can be improved.

[0008] (2) In the chair according to the embodiment of (1) above, it is preferable that the seat is supported at the front of the support mechanism so as to be rotatable about a first axis along the left-right direction, and the operating part is positioned on the seat at a location offset in the left-right direction from the support mechanism in a plan view. According to this embodiment, since the operating part is positioned offset from the support mechanism in the left-right direction in a plan view, interference between the operating part and the support mechanism can be avoided when the seat rotates.

[0009] (3) In the chair according to the embodiment of (2) above, it is preferable that the upright member is supported at the front of the support mechanism so as to be rotatable about a second axis along the left-right direction, and the operating part is attached to the lower surface of the seat. According to this embodiment, interference between the operating part and the upright member can be avoided when the upright member rotates around the second axis.

[0010] (4) In the chair according to the embodiment of (3) above, it is preferable to have a tilting mechanism that links the rotation of the seat and the upright member such that the amount of rotation of the seat about the first axis is smaller than the amount of rotation of the upright member about the second axis. According to this embodiment, since the amount of rotation of the seat around the first axis is small compared to the amount of rotation of the upright member around the second axis, the feeling of the seat sinking down when the load support part rotates (for example, when reclining) can be reduced. This provides a good seating experience for the sitter. On the other hand, when the amount of rotation of the seat around the first axis becomes small compared to the amount of rotation of the upright member around the second axis due to the operation of the tilting mechanism, the distance between the upright member and the operating part around the second axis in a side view becomes narrower as the upright member rotates. However, according to this embodiment, since the operating part is provided on the underside of the chair, interference between the operating part and the upright member can be avoided even when the amount of rotation of the seat around the first axis is small compared to the amount of rotation of the upright member around the second axis.

[0011] (5) In the chair according to the embodiments of (2) to (4) above, it is preferable that the operating section is provided with an operating element that is rotatable around a third axis along the vertical direction. According to this embodiment, the controls can be easily operated when a hand is reached into the space below the seat from the side of the seat.

[0012] (6) In the chair according to the embodiment of (5) above, it is preferable that the operator is displaceable outward in the left-right direction around the third axis from the initial position. According to this embodiment, the controls can be easily operated when a hand is reached into the space below the seat from the side of the seat.

[0013] (7) In a chair according to any of the embodiments described in (1) to (6) above, it is preferable that the operating unit is provided between the seat and the support mechanism in the vertical direction. According to this embodiment, the impact of the operating part on the appearance of the chair can be reduced compared to configurations in which, for example, the operating part protrudes downward from the support mechanism or upward from the seat.

[0014] (8) In a chair according to any of the embodiments of (1) to (7) above, it is preferable that the chair is provided with a leg column extending downward from the rear end of the support mechanism, the operating mechanism includes a chair lifting mechanism that extends and retracts the leg column in the vertical direction, and the operating unit is provided in front of the leg column. According to this embodiment, even though the operating part is located behind the upright member, it is possible to position the operating part in a location that is easily accessible to the seated person when they lower their hands. Furthermore, it is possible to prevent the operating part from being located in the gap between the rear of the seat and the rear of the support mechanism. This makes it easier to secure a gap between the rear of the seat and the rear of the support mechanism. As a result, it is possible to provide a chair that has the appearance of the seat extending cantilevered backward from the support mechanism. [Effects of the Invention]

[0015] According to each of the above embodiments, it is possible to improve operability, as well as layout and appearance. [Brief explanation of the drawing]

[0016] [Figure 1] This is a perspective view of the chair from the right rear. [Figure 2] This is a partial side view of a chair. [Figure 3] This is a cross-sectional view corresponding to line III-III in Figure 1. [Figure 4] This is a view from arrow IV in Figure 2, showing a portion of the support base broken. [Figure 5] This is a cross-sectional view corresponding to the VV line in Figure 4. [Figure 6] This is an exploded perspective view of the superstructure. [Figure 7] It is a cross-sectional view corresponding to the VII-VII line of FIG. 2. [Figure 8] It is a perspective view around the connecting rod portion. [Figure 9] It is a cross-sectional view corresponding to the IX-IX line of FIG. 8. [Figure 10] It is a cross-sectional view corresponding to the X-X line of FIG. 2. [Figure 11] It is a cross-sectional view of the chair showing the reclining state.

Mode for Carrying Out the Invention

[0017] Next, embodiments of the present invention will be described based on the drawings. In the embodiments and modifications described below, corresponding components may be denoted by the same reference numerals and the description thereof may be omitted. In the following description, expressions indicating relative or absolute arrangements such as "parallel", "orthogonal", "center", "coaxial", etc. not only strictly represent such arrangements, but also represent states in which they are relatively displaced with tolerances and angles or distances that can obtain the same function. Further, in the present embodiment, "opposite" includes not only the case where the orthogonal directions (normal directions) of two surfaces coincide with each other, but also the case where the orthogonal directions intersect each other.

[0018] [Chair 1] FIG. 1 is a perspective view of the chair part 1 seen from the right rear. FIG. It is a partial side view of the chair 1. As shown in FIGS. 1 and 2, the chair 1 includes a support structure 2, a seat 3, an upper structure 4, and an operation unit 5. The chair 1 is configured such that the seat 3 is displaced rearward and downward in conjunction with the reclining operation of the upper structure 4. In the following description, directions such as front, rear, up, down, left, and right are the same as those of a person (seated person) sitting on the chair 1 in a normal posture. In this case, the arrow UP in the figure indicates upward, the arrow FR indicates forward, and LH indicates left. Further, in the following description, in the front-rear direction, up-down direction, and left-right direction, the side away from the center of the chair 1 may be referred to as the outer side, and the side toward the center of the chair 1 may be referred to as the inner side.

[0019] <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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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).

[0030] 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.

[0031] <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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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 portion 39a and the downward-sloping front portion 39b of the seat body 39. 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 outer peripheral portion of the lower surface of the seat shell 50 by wrapping around the outer peripheral edge of the seat shell 50 to the lower surface of the seat shell 50. The surface 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.

[0039] <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.

[0040] 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.

[0041] 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).

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] <Operation unit 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 bracket 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 support plate 41, in a portion located behind the upright member 60. A portion of the lever stay 110 protrudes outward (to the right) from the seat support plate 41 in the left-right direction.

[0060] 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.

[0061] 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 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 moves outward in the left-right direction, following the lower surface of the seat body 39.

[0062] 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.

[0063] 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 and 121b is a part on which a seated person or the like can hook their fingers when operating the operator 121.

[0064] The operator 121 is connected to the linkage mechanism 23 via the 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 rotational operation of the operator 121 around the operating axis O.

[0065] <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.

[0066] 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.

[0067] <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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] (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).

[0080] 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.).

[0081] 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.

[0082] 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.

[0083] 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]

[0084] 1: Chair 3: Za 3a: Seat surface 4: Upper structure (load support part) 5:Operation unit 12: Support base (support mechanism) 16: Pillar 18: Gas spring (operating mechanism) 22:Tilt mechanism 23: Interlocking mechanism (operating mechanism) 60: Upright member 101a: Backrest side 121: Operator 125: Mechanism C1: Main axis (second axis) C3: Seat support axis (1st axis) O: Operation axis (3rd axis)

Claims

1. A box-shaped support mechanism, A seat having an upward-facing seating surface, connected to the front of the support mechanism, and supported from below by the support mechanism such that a vertical gap is created between it and the rear of the support mechanism, A chair comprising: a load support section that supports the weight of a sitter above the seat, extending outward in the left-right direction relative to the seat, straddling the seat vertically in a side view, and having a pair of upright members connected to the front end of the support mechanism below the seat, and supporting the weight of a sitter above the seat, It is connected to the operating mechanism of the chair and includes an operating unit for operating the said operating mechanism, The operating section is provided on the seat of the chair in a portion located behind the uprighting member and in front of the rear end of the support mechanism.

2. The seat is supported at the front of the support mechanism so as to be rotatable about a first axis along the left-right direction. The chair according to claim 1, wherein the operating unit is positioned on the seat at a location offset in the left-right direction in a plan view with respect to the support mechanism.

3. The upright member is supported at the front of the support mechanism so as to be rotatable around a second axis along the left-right direction. The chair according to claim 2, wherein the operating unit is attached to the underside of the seat.

4. The chair according to claim 3, further comprising a tilting mechanism that links the rotation of the seat and the upright member such that the amount of rotation of the seat around the first axis is smaller than the amount of rotation of the upright member around the second axis.

5. The chair according to any one of claims 2 to 4, wherein the operating section comprises an operating element rotatably mounted around a third axis along the vertical direction.

6. The chair according to claim 5, wherein the operator is displaceable outward in the left-right direction around the third axis from its initial position.

7. The chair according to any one of claims 1 to 4, wherein the operating section is provided between the seat and the support mechanism in the vertical direction.

8. The support mechanism is provided with a leg column extending downward from the rear end, The aforementioned operating mechanism includes a chair lifting mechanism that extends and retracts the leg column in the vertical direction, The chair according to any one of claims 1 to 4, wherein the operating section is provided in front of the leg column.

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