Chair

Abstract

The present invention provides a chair with excellent design freedom capable of forming a space under the seat. The chair includes legs, a support base (B) mounted at the upper ends of the legs, a support body (C) supported so as to be rotatable relative to the support base (B), and a seat (D) having a seat frame (S) supported so as to be rotatable relative to the support body (C). The support body (C) has a rear axle frame (J) extending in the left-right direction and capable of supporting the seat frame (S) so as to be rotatable at the left and right end portions. The central portion in the left-right direction of the rear axle frame (J) is supported at the rear portion of the support base (B) so as to be rotatable in the front-rear direction via a main shaft (j1) extending in the left-right direction.

Description

Technical Field

[0001] The present invention relates to a chair suitable for use in an office or the like. Background Art

[0002] Conventionally, there has been known a chair in which a front frame extending upward and forward is provided on a support base, a connecting member (link) extending upward is provided near the base end portion of a back frame, and a seat is supported on upper end portions of these front frame and connecting member (for example, refer to Patent Document 1).

[0003] In such a chair, a space that allows the seat surface to flex downward is formed by the front frame provided on the support base and the connecting member provided on the back frame.

[0004] However, in the case of a chair having such a structure, the structures of the support base and the back frame are complicated due to the provision of the front frame and the connecting member. In other words, the degree of freedom in designing a space that can be formed under the seat in a conventional chair is limited.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2016 - 83114 Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] The present invention has been made in view of the above circumstances, and provides a chair having excellent degree of freedom in designing a space that can be formed under the seat.

[0010] Technical Means for Solving the Problems

[0011] That is, the present invention has the following configuration.

[0012] The chair according to Technical Means 1 includes legs, a support base mounted on upper end portions of the legs, a support body supported so as to be rotatable relative to the support base, and a seat having a seat frame supported so as to be rotatable relative to the support body. The support body has a first bridge frame extending in the left - right direction and capable of supporting the seat frame as being rotatable at left and right end portions. A central portion in the left - right direction of the first bridge frame is supported at the rear portion of the support base via a main shaft extending in the left - right direction so as to be rotatable in the front - rear direction.

[0013] Based on the chair described in Technical Solution 1, in the chair described in Technical Solution 2, the first bridge frame includes: a first bridge frame body that is curved in a downwardly convex manner when viewed from the front; and a main shaft holding portion that protrudes downward from the central portion in the left-right direction of the first bridge frame body and can hold the main shaft.

[0014] Based on the chair described in Technical Solution 1 or 2, the chair described in Technical Solution 3 includes a second bridge frame that extends in the left-right direction and is supported at the front portion of the support base so as to be rotatable in the front-rear direction. The seat frame includes a seat frame body in a frame shape, and the seat frame body is supported by the first bridge frame and the second bridge frame.

[0015] Based on the chair described in Technical Solution 3, in the chair described in Technical Solution 4, the seat frame body and the second bridge frame are integrally formed of synthetic resin.

[0016] Based on the chair described in Technical Solution 3 or 4, in the chair described in Technical Solution 5, the second bridge frame includes: a second bridge frame body having a curved portion that is curved in a downwardly convex manner when viewed from the front; and a front shaft holding portion that protrudes downward from the central portion in the left-right direction of the second bridge frame body and can hold the front shaft provided on the support base.

[0017] Based on the chair described in any one of Technical Solutions 1 to 5, in the chair described in Technical Solution 6, the support body is provided with a backrest mounting portion capable of mounting a backrest and an armrest mounting portion capable of mounting an armrest.

[0018] Based on the chair described in any one of Technical Solutions 1 to 6, in the chair described in Technical Solution 7, the support body includes the first bridge frame, left and right side frames extending rearward from the left and right side portions of the first bridge frame, and a rear frame connecting the rear end portions of the left and right side frames.

[0019] Based on the chair described in any one of Technical Solutions 1 to 7, in the chair described in Technical Solution 8, the support base includes: a support base body on which the main shaft is disposed; and a connecting member whose base end portion is pivotally connected to the support base body and whose top end portion is pivotally connected to the seat frame.

[0020] Effects of the Invention

[0021] As described above, according to the present invention, it is possible to provide a chair with excellent design freedom that can form a space under the seat. Description of the Drawings

[0022] Figure 1 It is a perspective view showing an embodiment of the present invention.

[0023] Figure 2 It is the front view of this embodiment.

[0024] Figure 3 It is the rear view of this embodiment.

[0025] Figure 4 It is the left view of this embodiment.

[0026] Figure 5 It is the right view of this embodiment.

[0027] Figure 6 It is the top view of this embodiment.

[0028] Figure 7 It is the bottom view of this embodiment.

[0029] Figure 8 It is the exploded perspective view of this embodiment.

[0030] Figure 9 It is the exploded perspective view of this embodiment.

[0031] Figure 10 It is the exploded perspective view of this embodiment.

[0032] Figure 11 It is the exploded perspective view of this embodiment.

[0033] Figure 12 It is the exploded right view of this embodiment.

[0034] Figure 13 It is the rear view of this embodiment with the backrest removed.

[0035] Figure 14 It is the partial enlarged front view of the backrest of this embodiment.

[0036] Figure 15 It is Figure 4 The sectional view taken along the line X-X in

[0037] Figure 16 It is Figure 2 The sectional view taken along the line Y-Y in

[0038] Figure 17 It is the exploded perspective view of this embodiment.

[0039] Figure 18 It is the top view of this embodiment.

[0040] Figure 19 It is the exploded perspective view of this embodiment.

[0041] Figure 20 It is the exploded perspective view of this embodiment.

[0042] Figure 21 It is a top view of this embodiment.

[0043] Figure 22 It is a partially enlarged perspective view of this embodiment.

[0044] Figure 23 It is an exploded perspective view of this embodiment.

[0045] Figure 24 It is an exploded perspective view of this embodiment.

[0046] Figure 25 It is a partially enlarged perspective view of this embodiment.

[0047] Figure 26 It is an enlarged left view of the support base of this embodiment.

[0048] Figure 27 It is an enlarged right view of the support base of this embodiment.

[0049] Explanation of reference numerals

[0050] 3... Rear axle frame main body (axle frame main body, first axle frame main body)

[0051] 4... Main shaft holding part

[0052] 5... Front axle frame main body (axle frame main body, second axle frame main body)

[0053] 6... Front axle holding part

[0054] B... Support base

[0055] C... Support body

[0056] D... Seat

[0057] E... Backrest

[0058] J... Rear axle frame (axle frame, first axle frame)

[0059] M... Seat frame main body

[0060] S... Seat frame

[0061] T... Front axle frame (axle frame, second axle frame) Detailed implementation mode

[0062] Hereinafter, with reference to Figures 1 - 27 One embodiment of the present invention will be described.

[0063] In this embodiment, the present invention is applied to an office swivel chair (hereinafter simply referred to as "chair") suitable for use in an office or the like.

[0064] The chair includes: leg A; a support base B mounted on the upper end of leg A; a support body C supported so as to be rotatable in the front-rear direction with respect to the support base B; a seat D, the front part of which is supported so as to be rotatable with respect to the support base B and the rear part of which is supported so as to be rotatable with respect to the support body C; a backrest E supported by the support body C; and armrests F supported by the support body C.

[0065] A locking mechanism Rc is provided on the chair, and the locking mechanism Rc is configured to be able to move the backrest E, the seat D, and the armrests F between a normal posture, which is a posture in a load-free state, and a reclined posture (not shown), which is a posture inclined rearward from the normal posture.

[0066] Hereinafter, each component of the chair will be described in detail.

[0067] <<Leg A>>

[0068] Leg A includes: a plurality of leg blades a1, which have leg wheels a11 at the tips and are arranged radially; and a leg support a2 erected at the base ends of the leg blades a1.

[0069] An air spring a3 capable of expanding and contracting in the vertical direction is provided inside the leg support a2. The leg support a2 is configured to be able to expand and contract in the vertical direction by the air spring a3, and can change the vertical position of the support base B mounted on the upper end to an appropriate position.

[0070] <<Support Base B>>

[0071] The support base B is supported by leg A and is configured to be able to perform a rotational movement. The support base B includes: a support base main body 1 fixed to the upper end of the leg support a2; and a connection member 2 rotatably supported at the front end of the support base main body 1 via a rear connection shaft j3 serving as a rear axis.

[0072] <Support Base Main Body 1>

[0073] The support base main body 1 is in a box shape extending in the front-rear direction and having a reaction spring arrangement space inside where a reaction spring 13 can be arranged. A cylindrical leg connection portion 11 for connecting the upper end of the air spring a3 is provided at the rear of the support base main body 1.

[0074] A main shaft j1 for supporting the support body C so as to be rotatable is arranged in the support base main body 1. That is, a pair of left and right main shaft support portions 12 capable of supporting both ends of the main shaft j1 extending in the left-right direction protrude upward at the rear of the support base main body 1.

[0075] The reaction spring 13 is interposed between the support base B and the support body C. The reaction spring 13 generates a reaction force that enables the backrest E and the seat D to return to the normal posture by applying force to the support body C. The front end of the reaction spring 13 is engaged with the rear connecting shaft j3 connecting the support base body 1 and the connecting member 2 via the cam member 13d, and the rear end is rotatably connected to the pressed shaft j5 arranged at the lower end of the support body C.

[0076] The rear connecting shaft j3 also serves as a rotation shaft j7 of a reaction force operating lever 14 capable of operating the reaction force spring 13. The pressed shaft j5 is held by a pair of holding arms 42 extending downward and forward from the main shaft support portion 12.

[0077] The reaction force operation lever 14 includes a lever body 141 exposed to the outside of the support base body 1 , and a rotation shaft j7 integrally attached to the lever body 141 .

[0078] A cam member 13d is provided on the rotation axis j7 to directly engage with the top end of the reaction force adjustment pin 13c in the reaction force spring 13. The reaction force adjustment pin 13c constitutes the axis of the reaction force spring 13. The reaction force adjustment pin 13c is configured to be able to protrude and retract relative to the front mounting portion 13b disposed at the front end of the spring body 13a of the reaction force spring 13. In addition, by rotating the reaction force operating lever 14, the cam member 13d is rotated, and the reaction force adjustment pin 13c is protruded and retracted, so that the elastic rebound force (Japanese: anti-rebound force) of the reaction force spring 13 can be changed.

[0079] In this embodiment, the reaction force operating lever 14 is rotatably operated so as to be able to take three postures that can change the engagement between the cam member 13 d and the reaction force adjustment pin 13 c .

[0080] That is, by the reaction force operating rod 14 taking three postures, the chair can select a reclining locked state in which the backrest E and the seat D do not recline, a strong reaction force reclining state in which the backrest E and the seat D have a strong reaction force and can recline (not shown), and a weak reaction force reclining state in which the backrest E and the seat D have a weak reaction force and can recline (not shown).

[0081] <Connection member 2>

[0082] The connecting member 2 is configured to be rotatable relative to the support base body 1. That is, the connecting member 2 is supported in a manner that allows rotation relative to the support base body 1 between a normal posture extending in a length direction substantially consistent with the length direction of the support base body 1 when viewed from the side, and an upright posture (not shown) in which the front end portion is moved upward compared to the normal posture in conjunction with the rearward tilting movement of the backrest E and the seat D.

[0083] Regarding the connecting member 2, the base end portion is pivotally connected to the support base body 1 and the top end portion is pivotally connected to the seat frame S. The front portion of the connecting member 2 is connected to the seat D via the front connecting shaft j2 serving as the front shaft, and the rear portion of the connecting member 2 is connected to the support base body 1 via the rear connecting shaft j3. The rear end edge and the front end edge of the connecting member 2 have a partially circular shape when viewed from the side. The two side portions of the front end edge of the support base body 1 are recessed in a shape that matches the shape of the rear end edge of the connecting member 2 and is partially circular.

[0084] The connecting member 2 is configured such that both ends of the front connecting shaft j2 extending in the left-right direction and one end of the rear connecting shaft j3 (the side opposite to the end where the rod body 141 is mounted) do not protrude to the outside. Specifically, the connecting member 2 supports both ends of the front connecting shaft j2 by the left connecting member 2a and the right connecting member 2b that are divided into left and right and have a substantially halved shape.

[0085] The support base B having the above structure forms a suitable appearance that can give a smooth impression to the user through the support base body 1 and the connecting member 2.

[0086] That is, as Figure 26 and Figure 27 shown, the support base body 1 has a first upper edge portion u1 and a first lower edge portion s1 that are configured to gradually separate from each other rearward and be straight when viewed from the side. Similarly, the connecting member 2 has a second upper edge portion u2 and a second lower edge portion s2 that are configured to gradually separate from each other rearward and be straight when viewed from the side.

[0087] The support base B sets the relative position of the support base body 1 and the connecting member 2 such that the first imaginary intermediate line c1 and the second imaginary intermediate line c2 are on the same straight line. The first imaginary intermediate line c1 is located in the middle of the first upper edge portion u1 and the first lower edge portion s1 of the support base body 1, and the second imaginary intermediate line c2 is located in the middle of the second upper edge portion u2 and the second lower edge portion s2 of the connecting member 2 in the normal posture.

[0088] In addition, the support base B is configured such that the left and right outer side surfaces 15 of the support base body 1 and the left and right outer side surfaces 21 of the connecting member 2 are respectively substantially coplanar.

[0089] Moreover, the support base B is set such that the upper surface portion 16 corresponding to the first upper edge portion u1 of the support base body 1 and the upper surface portion 22 corresponding to the second upper edge portion u2 of the connecting member 2 in the normal posture are substantially coplanar. Similarly, the support base B is set such that the lower surface portion 17 corresponding to the first lower edge portion s1 of the support base body 1 and the lower surface portion 23 corresponding to the second lower edge portion s2 of the connecting member 2 in the normal posture are substantially coplanar.

[0090] In addition, as Figure 7 shown, when viewed from below, the chair forms a substantially rectangular outline extending in the front-rear direction by the outer edge of the support base body 1, the outer edge of the connecting member 2, and the outer edge of the front axle holding portion 6 that constitutes the seat frame S.

[0091] <<Support body C>>

[0092] The support body C can cooperate with the support base B to support the seat D. The support body C is interposed between the support base B and the backrest E and between the support base B and the armrest F. In other words, the support body C can support the backrest E and the seat D. The support body C is provided with a backrest mounting portion k1, L1 for mounting the backrest E and an armrest mounting portion 32 for mounting the armrest F. The support body C is set to take a posture that is inclined forward as a whole with respect to the horizontal in the normal posture.

[0093] The support body C includes: a rear bridge frame J, which is a first bridge frame having a portion extending in the left-right direction; left and right side frames K, which extend rearward from the left and right side portions of the rear bridge frame J; and a rear frame L, which connects between the rear end portions of the left and right side frames K. The support body C has an annular frame portion w1 that is continuously formed in a ring shape.

[0094] In this embodiment, the rear bridge frame J, the left and right side frames K, and the rear frame L are integrally formed of metal. The support body C is supported via the main shaft j1 at the rear portion of the support base B that is mounted on the upper end portion of the leg A so as to be rotatable in the front-rear direction. The support body C can support the seat frame S disposed thereon in a manner that is rotatable in the front-rear direction.

[0095] <Rear bridge frame J>

[0096] The rear bridge frame J is disposed below the seat D. The rear bridge frame J includes: a rear bridge frame main body 3, which is a first bridge frame main body that is curved convex downward when viewed from the front; and a main shaft holding portion 4, which protrudes downward from the central portion in the left-right direction of the rear bridge frame main body 3 and can hold the main shaft j1 supported by the support base B.

[0097] [Rear bridge frame main body 3]

[0098] The rear bridge frame main body 3 is long in the left-right direction, and its left-right width dimension is set to be approximately the same as the left-right width dimension of the seat frame main body M. The rear bridge frame main body 3 as a whole has a shape in which a strip-shaped plate extending in the left-right direction is bent so that the middle portion is located lower than the both end portions. In other words, the rear bridge frame main body 3 is in an inverted arch shape when viewed from the front.

[0099] The rear bridge frame main body 3 is set such that in the case where the support body C takes a normal posture, its upper surface takes a posture facing obliquely upward. That is, the rear bridge frame main body 3 is configured such that in the case where the backrest E is reclined, the portion of the seat support shaft j4 can be located above the main shaft j1 compared to the normal posture.

[0100] The rear bridge frame main body 3 includes: a main body central portion 3a, which is located inside the frame portion w2 of the seat frame main body M in a top view and has substantially the same thickness dimension in the left-right direction; and main body end portions 3b, which extend outward from both end portions of the main body central portion 3a and are set to have a greater front-rear width and thickness dimension than the main body central portion 3a.

[0101] The rear bridge frame main body 3 as a whole has a shape that is curved convexly downward, but in addition to this, the upper part of the main body central portion 3a is recessed downward more than the main body end portions 3b, expanding the space sp that can allow the seat main body P to deflect downward.

[0102] The main body central portion 3a integrally projects downward from the middle portion in the left-right direction to provide a main shaft holding portion 4.

[0103] The rear bridge frame main body 3 can support the seat frame S at both left and right end portions via the seat support shaft j4 so as to be rotatable. That is, in the rear bridge frame main body 3, first shaft holding portions 31 that project upward are provided on both left and right sides respectively, and the seat support shaft j4 of the pivot support seat D is held by each shaft holding portion 31.

[0104] In other words, the first shaft holding portions 31 that can support the seat D so as to be rotatable via the seat support shaft j4 bulge in the main body end portions 3b. In addition, the seat support shaft j4 is set to be located above and in front of the main shaft j1 in a side view in order to be able to constitute a weight-sensing locking mechanism Rc.

[0105] The rear bridge frame main body 3 is provided with armrest mounting portions 32 at both end portions that can mount the armrest F. The armrest mounting portion 32 includes a recess b1 that opens outward, and the base end portion f21 of the armrest F or the cover member G can be embedded in the recess b1. The armrest mounting portion 32 is formed in the main body end portions 3b of the rear bridge frame main body 3.

[0106] The recess b1 is composed of an upper wall b12, a lower wall b13, a front wall b14, a rear wall b15, and a back wall b16, forming an insertion space b11 surrounded by them. The base end portion f21 of the armrest F is inserted into the insertion space b11, and the base end portion f21 of the armrest F is embedded in the recess b1. On the inner surface side of the upper wall b12, a guide recess b17 that extends in the insertion and extraction direction of the base end portion f21 of the armrest F and nut portions n1 provided on both sides of the guide recess b17 are provided.

[0107] The guiding recess b17 can be engaged with the positioning projection f22 provided at the base end portion f21 of the armrest F to position the base end portion f21 of the armrest F. The armrest F is attached to the support body C by inserting a screw v1 through a screw insertion hole h1 provided in the base end portion f21 of the armrest F and then screwing the screw v1 into the nut portion n1.

[0108] In addition, when the armrest F is not attached to the chair of this embodiment, as Figure 20 shown, in order to prevent the recess b1 from being exposed to the outside, the cover member G can be fitted into the recess b1.

[0109] [Spindle holding portion 4]

[0110] The spindle holding portion 4 protrudes downward from the central portion in the left - right direction of the rear bridge frame body 3 and can hold the spindle j1 disposed on the support base B.

[0111] The spindle holding portion 4 is provided with a spindle insertion hole 41 extending in the left - right direction for holding the spindle j1. The spindle holding portion 4 is sized to be disposed between the spindle support portions 12 which are provided in pairs on the left and right of the support base B and are in the form of standing walls.

[0112] In the spindle holding portion 4, at a position lower than the spindle insertion hole 41, a pair of left - right holding arms 42 extend forward and downward. The pressed shaft j5 to which the rear end portion of the reaction spring 13 is connected is supported between the tip portions of the holding arms 42. That is, the support body C is configured such that the pressed shaft j5 located at a position lower than the spindle j1 is pressed rearward by the reaction spring 13, so that it can take a normal posture in a load - free state.

[0113] <Left and right side frames K>

[0114] The left and right side frames K extend rearward in a substantially straight line from the inner portions of the main body end portions 3b of the rear bridge frame body 3. The left and right side frames K are provided with backrest mounting portions k1 for mounting the backrest E on the left and right outer portions.

[0115] The backrest mounting portions k1 provided on the left and right side frames K include a fitting portion that is fitted into the backrest E and a screw insertion hole h2 that penetrates in the left - right direction for inserting a screw v2 screwed into the backrest E. More specifically, the fitting portion of the backrest mounting portion k1 is mainly composed of a positioning projection k11 that protrudes outward from the middle portion in the up - down direction of the outer portion of the left and right side frames K.

[0116] <Rear frame L>

[0117] The rear frame L is installed between the rear ends of the left and right side frames K. The rear frame L as a whole has a shape that is curved so as to protrude rearward. The rear frame L is provided with a backrest mounting portion L1 for mounting the backrest E at the outer side portion, that is, the rear portion.

[0118] The backrest mounting portion L1 provided on the rear frame L includes a fitting portion that is a portion fitted into the backrest E, and a screw insertion hole h3 that penetrates in the front-rear direction and through which a screw v3 screwed into the backrest E is inserted. More specifically, the fitting portion of the backrest mounting portion L1 is configured with a positioning protrusion L11 that protrudes outward from the middle portion in the vertical direction of the outer side portion of the rear frame L as the main body.

[0119] <Ring-shaped frame portion w1>

[0120] The support body C includes a ring-shaped frame portion w1, and the ring-shaped frame portion w1 has a fitting portion that can be fitted with the connecting portion 8 of the backrest main body Q. The ring-shaped frame portion w1 is composed of a frame-shaped portion that is continuously ring-shaped.

[0121] Specifically, the ring-shaped frame portion w1 is composed of the rear axle frame J, the left and right side frames K, and the rear frame L. When viewed from above, the ring-shaped frame portion w1 is substantially in the shape of a cross. And, fitting portions that can be fitted with the backrest E are provided on the outer side portions of the left and right side frames K and the rear side portion of the rear frame L that constitute the ring-shaped frame portion w1.

[0122] The fitting portions provided on the outer side portions of the left and right side frames K and the rear frame L are configured with positioning protrusions k11, L11 that are fitted into the backrest E as the main body.

[0123] In addition, as Figure 18 shown, with regard to this chair, in order to appropriately ensure the amount of deflection of the seat main body P downward, the positions of the seat frame S and the support body C are set such that the space w2s surrounded by the frame-shaped portion w2 of the seat frame main body M overlaps with the space w1s surrounded by the ring-shaped frame portion w1 of the support body C when viewed from above.

[0124] In addition, the ring-shaped frame portion w1 is set to take a posture that is inclined forward as a whole with respect to the horizontal in the normal posture.

[0125] <<Seat D>>

[0126] The seat D includes a seat frame S configured to include a frame-shaped member that is continuously ring-shaped, and a seat main body P that has a seating surface and is mounted on the seat frame S.

[0127] <Seat frame S>

[0128] The seat frame S includes a seat frame body M in a frame shape and a front bridge frame T that connects between the left and right end portions of the seat frame body M and is provided in a bridge shape. The seat frame body M and the front bridge frame T are integrally formed of synthetic resin. The seat frame S has a frame portion w2 that is continuously annular.

[0129] [Seat frame body M]

[0130] The seat frame body M constitutes a frame portion w2 that is continuously annular. Specifically, it is substantially square-shaped in a top view. The seat frame body M can support the peripheral portion of the seat body P from below.

[0131] The seat frame body M includes left and right seat side frame portions m1 extending in the front-rear direction, a seat front frame portion m2 connecting between the front end portions of the left and right seat side frame portions m1, and a seat rear frame portion m3 connecting between the rear end portions of the left and right seat side frame portions m1. That is, the seat frame body M is composed of the left and right seat side frame portions m1, the seat front frame portion m2, and the seat rear frame portion m3 to form a frame portion w2 that is continuously rectangular and annular.

[0132] The seat frame body M is supported from below by the rear bridge frame J that constitutes the support body C and the front bridge frame T integrated with the seat frame body M. A plurality of screw insertion holes h4 that penetrate in the up-down direction for the screws v4 screwed into the seat body P to pass through are provided in the seat frame body M. A plurality of ribs rv are provided along the length direction on the upper surface side of the seat frame body M.

[0133] The left and right seat side frame portions m1 extend substantially linearly in the front-rear direction. On the left and right seat side frame portions m1, a second shaft holding portion m11 that can hold the seat support shaft j4 is provided to protrude downward from the inner edge portion of the rear part. That is, the seat frame S can rotate in the front-rear direction with respect to the support body C by the seat support shaft j4 being held by the second shaft holding portion m11 provided in the seat frame S and the first shaft holding portion 31 provided in the support body C.

[0134] The seat front frame portion m2 extends substantially linearly in the left-right direction. The seat rear frame portion m3 is integrally shaped to be curved convexly toward the rear.

[0135] [Front bridge frame T]

[0136] The front bridge frame T extends in the left-right direction and can support the seat frame body M from below. The front bridge frame T is supported at the front portion of the support base B so as to be rotatable in the front-rear direction with respect to the support base B.

[0137] The front axle frame T includes: a front axle frame main body 5, which is a second axle frame main body having a bent shape portion 5a that bends convexly downward when viewed from the front; and a front axle holding portion 6, which protrudes downward from the central portion in the left-right direction of the front axle frame main body 5 and can hold the front connecting shaft j2, which is a front axle, provided on the support base B.

[0138] An operating lever V for raising and lowering the seat D relative to the leg A is disposed on the left side portion of the front axle frame T.

[0139] (Front axle frame main body 5)

[0140] The front axle frame main body 5 includes a bent shape portion 5a that bends convexly downward when viewed from the front, and left and right upright walls 5b, 5c that extend upward from the left and right end portions of the bent shape portion 5a and whose upper end portions are connected to the left and right seat side frame portions m1 of the seat frame main body M.

[0141] An operating lever support portion 51 for supporting the operating lever V for raising and lowering the seat is provided on the front axle frame main body 5.

[0142] The bent shape portion 5a is in an inverted arch shape when viewed from the front. The bent shape portion 5a extends substantially linearly in the left-right direction when viewed from above and below. The bent shape portion 5a has substantially the same thickness dimension when viewed from the front and extends in the left-right direction.

[0143] The left and right upright walls 5b, 5c connect the seat frame main body M and the bent shape portion 5a. The upper end portions of the left and right upright walls 5b, 5c are connected to the front end portions of the left and right seat side frame portions m1. In this embodiment, the operating lever V is disposed on the left upright wall 5b. The width dimension of the left upright wall 5b in the front-rear direction is set larger than the width dimension of the right upright wall 5c in the front-rear direction.

[0144] The left upright wall 5b has a rectangular through-hole 5d that penetrates in the left-right direction. An operating lever holding member Z that can support the operating lever V so as to be rotatable is mounted on the inner surface of the left upright wall 5b.

[0145] The operating lever V is supported by the operating lever support portion 51. The operating lever V includes: an operating end tn that protrudes outward through the through-hole 5d formed in the left upright wall 5b; a rod shaft j6 that protrudes from the base end portion va and is pivotally supported by the rod holding member Z and extends forward and backward; and a wire support portion ws that is disposed below the rod shaft j6 in the base end portion va. The wire support portion ws can support the end wyt of a wire wy that transmits an operating force to the gas spring a3 provided on the leg A.

[0146] The lever support portion 51 includes a lever holding member Z, which is installed on the inner side surface of the left standing wall 5b and the left end portion of the bent portion 5a, and can support the operating end tn of the operating lever V so as to be rotatable in the vertical direction.

[0147] The lever holding member Z includes: a shaft support portion z1 that can support the lever shaft j6 disposed at the base end portion va of the operating lever V so as to be rotatable; a wire communication path z2 that allows the wire wy to communicate in the left-right direction; a screw insertion hole h5 that is provided through the inner portion and through which a screw v5 screwed into the bent portion 5a is inserted; and a screw insertion hole h6 that is provided through the outer portion and through which a screw v6 screwed into the upper portion of the left standing wall 5b is inserted. A storage space za for storing the base end portion va of the operating lever V is formed in the lever holding member Z.

[0148] When the operating end tn moves upward by an operation based on the user's finger, the operating lever V pulls the end wyt of the wire wy supported by the wire support portion ws toward the operating end tn side. And, the wire wy actuated by the operating lever V can rotate the pressing member ps pivotally supported at the rear end portion of the support base B and can press the working pin of the gas spring a3 downward by the pressing member ps.

[0149] In this embodiment, since the wire wy that can be actuated by the operating lever V is provided above the bent portion 5a of the front axle frame T and the support base B, it is not easily noticeable from the outside.

[0150] (Front axle holding portion 6)

[0151] The front axle holding portion 6 is provided to droop downward from the center portion in the left-right direction of the bent portion 5a. An axle insertion hole 61 extending in the left-right direction is provided in the front axle holding portion 6.

[0152] In a state where the front connecting shaft j2 is inserted into the axle insertion hole 61 of the front axle holding portion 6, both end portions thereof are clamped by the left connecting member 2a and the right connecting member 2b of the connecting member 2. That is, the front axle holding portion 6 is disposed between the left connecting member 2a and the right connecting member 2b. In other words, the left-right width dimension of the front axle holding portion 6 is set to be smaller than the left-right width dimension of the connecting member 2.

[0153] <Seat main body P>

[0154] The seat main body P includes: a seat intermediate frame p1 disposed on the seat frame main body M; a seat cushion p2 disposed on the seat intermediate frame p1; and a seat tension fabric p3 that is an exterior material covering the upper surface side and the side surface side of the seat intermediate frame p1 and the seat cushion p2.

[0155] The seat intermediate frame p1 includes an outer frame portion p11 having substantially the same shape as the seat frame body M in a plan view, and a flexible mesh tensioner p12 which is stretched inside the outer frame portion p11. Figure 18 In order to facilitate the use of reference numerals to describe other parts, the tensioning member p12 is represented as a coarse mesh.

[0156] The seat cushion p2 is formed of a foam material such as urethane into a generally rectangular shape in a plan view and is a known structure capable of exerting a predetermined cushioning property. The center portion of the seat cushion p2 is supported from below by a stretchable tensioner p12 of the seat intermediate frame p1.

[0157] The seat tensioning fabric p3 is made of sewn fabric. The end portion, ie, the peripheral edge of the seat tensioning fabric p3 can be accommodated in the lower surface side of the outer frame portion p11 of the seat intermediate frame p1 and can be clamped by the outer frame portion p11 of the seat intermediate frame p1 and the seat frame body M of the seat frame S.

[0158] When a downward load is applied by a seated person, the center of the seat tensioning fabric p3 and the seat cushion p2 is pressed downward with respect to the seat body P, and as a result, the tensioning member p12 of the seat intermediate frame p1 is bent and deformed downward. The seat frame body M disposed under the seat intermediate frame p1 is in a frame shape corresponding to the outer frame portion p11, and the front axle frame T and the rear axle frame J supporting the seat frame body M are each curved in a convex manner toward the downward direction.

[0159] Therefore, even when the center portion of the seat body P is greatly bent downward due to the load of the seated person, the seat frame body M can cooperate with the seat intermediate frame body p1 provided with the tensioner p12 to allow the bending of the center portion of the seat body P within a certain range and can appropriately support the peripheral portion of the seat body P. Furthermore, the front axle frame T and the rear axle frame J that are bent downward are each in an appropriate form that is unlikely to interfere with the seat body P that is bent downward.

[0160] <<Backrest E>>

[0161] The backrest E includes a backrest body Q formed of synthetic resin and a tension fabric R as an exterior material covering the backrest body Q. The backrest E is supported via a support body C relative to a support base B so as to be rotatable in the front-rear direction.

[0162] <Backrest body Q>

[0163] The backrest body Q comprises: a backrest base 7, which is located on the back side of the seated person and has a shape capable of supporting the back of the seated person from the rear side; and a connecting portion 8, which is provided under the backrest base 7 and is substantially The structure is in the shape of a Chinese character "C" and is connected to the supporting body C.

[0164] The connecting portion 8 includes left and right side connecting portions 81 that are paired left and right and extend in the front-rear direction, and a rear connecting portion 82 that connects between the rear end portions of the left and right side connecting portions 81. Moreover, each inner side portion of the left and right side connecting portions 81 can be fitted to the outer side portion of the side frame of the support body C, and the front portion of the rear connecting portion 82 can be fitted to the rear side portion of the rear frame L of the support body C.

[0165] The connecting portion 8 of the backrest E is guided by a rail-shaped positioning projection k11 that extends in the front-rear direction and is provided on the side portion of the support body C, and is slid and installed in a manner of being inserted into the rear portion of the support body C.

[0166] When viewed from above as a whole, the connecting portion 8 is substantially in a shape like the Chinese character "zi" through the left and right side connecting portions 81 and the rear connecting portion 82. The connecting portion 8 can be fitted from the outside to the rear portion of the support body C that is formed by the left and right side frames K and the rear frame L and is convex when viewed from above as a whole.

[0167] In other words, the backrest main body Q is provided with outer fitting portions 81a and 82a at the inner side portions of the left and right side connecting portions 81 and the front portion of the rear connecting portion 82, and the outer fitting portions 81a and 82a can be externally fitted to the fitting portions for backrest installation provided on the support body C.

[0168] The outer fitting portion 81a of the left and right side connecting portions 81 includes: a recessed portion 81b provided at the middle portion in the up-down direction and capable of being fitted with the positioning projection k11 formed on the left and right side frames K of the support body C; a tension fabric holding portion 81c provided above and below the recessed portion 81b and capable of holding the end portion of the tension fabric R; and a nut portion n2 for screwing the screw v2 after the screw passes through the screw insertion hole h2 of the positioning projection k11. For example, the end portion of the tension fabric R to which a synthetic resin strip member (not shown) is sewn is pressed into the tension fabric holding portion 81c.

[0169] In addition, a tension fabric end portion storage space 81d capable of storing the end portion of the tension fabric R is formed at the front end portion of the left and right side connecting portions 81. A notch 81e for easily guiding the end portion of the tension fabric R into the tension fabric end portion storage space 81d is formed at the outer edge of the front end portion of the left and right side connecting portions 81.

[0170] The outer fitting portion 82a of the rear connection portion 82 includes: a recessed portion 82b provided at the middle portion in the vertical direction and capable of fitting with a positioning projection L11 formed on the rear frame L of the support C; a tension fabric holding portion 82c provided above and below the recessed portion 82b and capable of holding the end portion of the tension fabric R; and a nut portion n3 for screwing a screw v3 after the screw passes through a screw insertion hole h3 of the positioning projection L11. For example, the end portion of the tension fabric R to which a synthetic resin strip member (not shown) is sewn is pressed into the tension fabric holding portion 82c.

[0171] In addition, in this embodiment, the backrest main body Q is composed of a central member q1 that forms the main part of the backrest base 7, and left and right side members q2 that are stop-mounted on the left and right side portions of the central member q1. The inner side portion of the side member q2 is fixed to the central member q1 with screws v7 in a state of being fitted inside the outer side portion of the central member q1. The central member q1 is formed of a synthetic resin having better flexibility than the side member q2. Since the side member q2 is a member including left and right side connection portions 81 that protrude forward, it is formed of a synthetic resin having higher strength than the central member q1.

[0172] <Tension fabric R>

[0173] The tension fabric R is a bag-shaped member capable of covering substantially the entire backrest main body Q, and is sewn from a fabric with a sheet-like cushioning material (not shown) attached thereto.

[0174] In addition, the tension fabric R can adopt an appropriate structure. As the tension fabric R, for example, a structure in which a material having cushioning properties is disposed between two fabrics and then quilted can be cited.

[0175] The fitting portions of the outer fitting portions 81a and 82a of the backrest main body Q and the support C are fitted in a state where the end portion of the tension fabric R, that is, the lower end portion that becomes the open end, is sandwiched between the backrest main body Q and the support C. In addition, the left and right side end portions of the lower end edge of the tension fabric R are accommodated in a tension fabric end portion accommodation space 81d that is a space formed at the front end portions of the left and right side connection portions 81 of the backrest main body Q, and are blocked by the back surfaces of the main body end portions 3b of the rear bridge frame main body 3 that constitutes the support C.

[0176] <<Armrest F>>

[0177] The armrest F includes: an armrest main body f1 that has a rectangular frame shape in a side view and has an upward elbow rest f11 at the upper end; and an armrest arm f2 that extends downward from the front portion of the lower end of the armrest main body f1.

[0178] The base end portion f21, which is the lower end portion of the armrest f2, is connected to the armrest mounting portion 32 provided on the rear axle frame J. The base end portion f21 of the armrest f2 is in a form that is embedded in the recess b1 of the rear axle frame J.

[0179] The base end portion f21 of the armrest f2 is provided with a positioning projection f22 that protrudes on the upper surface side and extends in the left - right direction, and screw insertion holes h1 that penetrate in the up - down direction and are provided in the front and rear of the positioning projection f22. The positioning projection f22 of the base end portion f21 can be engaged with the guide recess b17 formed in the upper wall b12 of the recess b1 of the rear axle frame J.

[0180] <<Locking mechanism Rc>>

[0181] The locking mechanism Rc is used to act synchronously with the tilting movements of the seat D and the backrest E.

[0182] The locking mechanism Rc provided in the chair is configured with the support base B, the support body C, the seat D, and the backrest E as the main components. The support body C is supported by the support base B via the main shaft j1. The seat D is supported by a connecting member 2 pivotally supported on the support base body 1 via the front connecting shaft j2 and is also supported by the support body C via the seat support shaft j4. The backrest E is mounted on the support body C.

[0183] In this embodiment, the seat support shaft j4 is arranged in front of the main shaft j1, and the connecting member 2 is arranged in front of the main shaft j1. The connecting member 2 is supported by the support base body 1 via the rear connecting shaft j3 so as to be rotatable relative to the support base body 1. Therefore, the locking mechanism Rc is a so - called weight - sensing type mechanism, and is configured such that when the backrest E tilts backward from the normal position, the seat D moves backward while rising as a whole.

[0184] In addition, since the backrest E has a structure that is fitted into the support body C and is firmly integrated with the support body C, it can rotate relative to the support base B together with the support body C.

[0185] The chair of this embodiment is configured to be supported from below by a front axle frame T extending in the left - right direction and a rear axle frame J extending in the left - right direction for a frame - shaped seat frame body M.

[0186] Therefore, the degree of freedom in design for forming a space sp in which the seat main body P having a seating surface can flex downward is excellent. Since the front axle frame T and the rear axle frame J each extend in a substantially straight line in the left - right direction in plan view, it is easy to perform a design that ensures strength without complicating the shape.

[0187] Moreover, a front axle holding portion 6 is provided at the lateral center portion of the front axle frame T extending in the left-right direction, and a main shaft holding portion 4 is provided at the lateral center portion of the rear axle frame J. Therefore, the chair is excellent in the degree of freedom of design for locally disposing the front axle holding portion 6 and the main shaft holding portion 4 at the center portion in the left-right direction while maintaining the strength capable of holding the front connecting shaft j2 and the main shaft j1.

[0188] That is to say, in this chair, the front axle holding portion 6 and the main shaft holding portion 4 are locally unified at the center portion in the left-right direction respectively. Therefore, it is easy to design the width dimension in the left-right direction of the front axle holding portion 6 and the main shaft holding portion 4 to be short.

[0189] As a result, the width dimension of the support base portion B capable of supporting the front axle holding portion 6 and the main shaft holding portion 4 can also be designed to be as small as possible. The chair having such a structure can easily design the support base portion B to have a suitable appearance that can give an elongated and smooth impression.

[0190] In particular, since the front axle holding portion 6 and the main shaft holding portion 4 are arranged in a single block at the center portion in the left-right direction, the support base body 1 has a structure in which front axle support portions 12 are provided at both side portions of the main shaft holding portion 4 in a single block, and the connecting member 2 has a structure in which left and right connecting members 2a and 2b are provided at both side portions of the front axle holding portion 6 in a single block. Therefore, it is difficult for the entire support base portion B to be complicated and it is easy to achieve a relatively simple form.

[0191] In addition, since the chair of the present embodiment is provided with an armrest mounting portion 32 on the rear axle frame J capable of supporting the seat D so as to be rotatable in the front-rear direction, the armrest F can be supported at a suitable position with excellent strength.

[0192] The chair of the present embodiment has a structure in which the backrest E is fitted to the support body C having an annular frame portion w1. Therefore, by using the support body C having the annular frame portion w1, it is possible to provide a chair having excellent degree of freedom of design for obtaining a structure excellent in weight reduction and a suitable appearance while maintaining the strength capable of supporting the backrest E.

[0193] In the chair of the present embodiment, the operating lever V is arranged at the side portion of the front axle frame T extending in the left-right direction. Therefore, it is possible to provide a chair in which the operating lever V is arranged at a suitable position close to the seating surface of the seat main body P and easy for the user to operate.

[0194] As described above, the chair according to the present embodiment includes legs A, a support base portion B mounted at the upper end portions of the legs A, a support body C supported by the support base portion B so as to be rotatable relative to the support base portion B, and a seat D having a seat frame S supported by the support body C so as to be rotatable relative to the support body C.

[0195] Further, the support body C has a rear axle frame J as a first bridge frame extending in the left - right direction and capable of supporting the seat frame S rotatably at its left and right end portions. The central portion in the left - right direction of the rear axle frame J is supported by the rear portion of the support base B via a main shaft j1 extending in the left - right direction so as to be rotatable in the front - rear direction.

[0196] Therefore, it is possible to provide a chair with excellent design freedom capable of forming a space sp under the seat D.

[0197] That is, since the support body C has a rear axle frame J extending in the left - right direction, by setting its shape, it is possible to flexibly form a space sp under the seat D.

[0198] The rear axle frame J includes: a rear axle frame body 3, which is a first bridge frame body bent convex downward when viewed from the front; and a main shaft holding portion 4, which protrudes downward from the central portion in the left - right direction of the rear axle frame body 3 and is capable of holding the main shaft j1.

[0199] Therefore, the rear axle frame J can be flexibly designed by the shape of the rear axle frame body 3 to appropriately form a space sp under the seat D and to compactly arrange the main shaft j1 and the support base B in the middle portion in the left - right direction.

[0200] It has a front axle frame T as a second bridge frame extending in the left - right direction and supported by the front portion of the support base B so as to be rotatable in the front - rear direction. The seat frame S has a frame - shaped seat frame body M, and the seat frame body M is supported by the rear axle frame J and the front axle frame T.

[0201] Therefore, since the seat frame body M is supported by the rear axle frame J and the front axle frame T, it is possible to stably support the seat frame body M and appropriately form a space sp under the seat frame body M.

[0202] The seat frame body M and the front axle frame T are integrally formed of synthetic resin.

[0203] Therefore, the seat frame body M and the front axle frame T can be integrally processed in a form with excellent strength.

[0204] The front axle frame T includes: a front axle frame body 5, which is a second bridge frame body having a bent - shape portion 5a bent convex downward when viewed from the front; and a front axle holding portion 6, which protrudes downward from the central portion in the left - right direction of the front axle frame body 5 and is capable of holding a front connecting shaft j2, which is a front axle, provided on the support base B.

[0205] Therefore, the front axle frame T can be flexibly designed according to the shape of the front axle frame body 5 to appropriately form a space sp under the seat D and to compactly arrange the front connecting shaft j2 and the support base B at the middle part in the left-right direction.

[0206] The support body C is provided with a backrest mounting portion k1, L1 capable of mounting the backrest E and an armrest mounting portion 32 capable of mounting the armrest F.

[0207] Therefore, the support body C can not only cooperate with the support base B to support the seat D, but also support the backrest E and the armrest F only by the support body C. Therefore, it is possible to appropriately suppress the complication of the design of the support base B and contribute to the compactness and simplicity of the support base B.

[0208] The support body C includes a rear axle frame J, left and right side frames K extending rearward from the left and right side portions of the rear axle frame J, and a rear frame L connecting the rear end portions of the left and right side frames K.

[0209] Therefore, the support body C adopts a structure that surrounds in a ring shape, and it is easy to exhibit the predetermined rigidity capable of supporting the seat D, the backrest E, and the armrest F.

[0210] The support base B includes: a support base body 1 on which the main shaft j1 is disposed; and a connecting member 2 whose base end portion is pivotally connected to the support base body 1 and whose tip end portion is pivotally connected to the seat frame S.

[0211] Therefore, the seat frame S is supported by the support base body 1 via the support body C and is supported by the connecting member 2 so as to be rotatable relative to the connecting member 2, and thus it is possible to appropriately perform a locking operation.

[0212] In addition, the present invention is not limited to the embodiments described in detail above.

[0213] It is sufficient that the support body includes a bridge frame, and it is not limited to the structure shown in this embodiment. For example, the support body may not include the left and right side frames and / or the rear frame.

[0214] The bridge frame constituting the support body can be formed into an appropriate shape and is not limited to the shape shown in the above embodiment.

[0215] The seat frame is not limited to integrally forming the seat frame body and the bridge frame with synthetic resin. The seat frame body and the bridge frame may also be composed of separately independent components.

[0216] The bridge frame constituting the seat frame can be formed into an appropriate shape and is not limited to the shape shown in the above embodiment.

[0217] In addition, the specific structure of each part is not limited to the above embodiment, and various deformations can be made without departing from the gist of the present invention.

Claims

1. A chair, comprising legs, a support base mounted at upper ends of the legs, a support body supported to be rotatable relative to the support base, and a seat having a seat frame supported to be rotatable relative to the support body, characterized in that the support body has a first bridge frame extending in the left-right direction and capable of supporting the seat frame to be rotatable at left and right end portions thereof, and a central portion in the left-right direction of the first bridge frame is supported at a rear portion of the support base via a main shaft extending in the left-right direction to be rotatable in the front-rear direction.

2. The chair according to claim 1, characterized in that the first bridge frame includes: a first bridge frame main body curved in a downwardly convex manner when viewed from the front; and a main shaft holding portion projecting downward from a central portion in the left-right direction of the first bridge frame main body and capable of holding the main shaft.

3. The chair according to claim 1, characterized in that it includes a second bridge frame extending in the left-right direction and supported at a front portion of the support base to be rotatable in the front-rear direction, the seat frame includes a frame-shaped seat frame main body supported by the first bridge frame and the second bridge frame.

4. The chair according to claim 3, characterized in that the seat frame main body and the second bridge frame are integrally formed of synthetic resin.

5. The chair according to claim 3, characterized in that the second bridge frame includes: a second bridge frame main body having a curved shape portion curved in a downwardly convex manner when viewed from the front; and a front shaft holding portion projecting downward from a central portion in the left-right direction of the second bridge frame main body and capable of holding a front shaft provided on the support base.

6. The chair according to claim 1, characterized in that a backrest mounting portion capable of mounting a backrest and an armrest mounting portion capable of mounting armrests are provided on the support body.

7. The chair according to claim 1, characterized in that the support body includes the first bridge frame, left and right side frames extending rearward from left and right side portions of the first bridge frame, and a rear frame connecting between rear end portions of the left and right side frames.

8. The chair according to claim 1, characterized in that the support base includes: a support base main body on which the main shaft is disposed; and a connecting member pivotally connected at a base end portion to the support base main body and at a top end portion to the seat frame.

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