CN105595655B - Chair (Ref. TM. chair) - Google Patents

Abstract

The invention provides a chair, which is a chair with a seat capable of tilting relative to a supporting base and has a structure that the management of related parts and/or the processing during assembly are convenient. A chair in which a seat is supported on a support base via a connecting member, wherein: interposing a seat tilt movement adjusting unit for adjusting a degree of tilt of the seat with respect to the support base between the support base and the seat; the seat tilt movement adjusting unit is assembled to the base so as to be integrally handled with the base; the base is attached to one of the seat and the support base, and the coupling member is supported by the other so that a distance between the coupling member and the seat or the support base can be changed.

Description

Chair (Ref. TM. chair)

Technical Field

The present invention relates to a chair suitable for use in offices and the like.

Background

A chair in which a base support base is supported has been known (see, for example, patent document 1).

However, among such chairs, there are also chairs in which the seat can be tilted forward with respect to the support base.

In general, conventional chairs employ a complex structure using a considerable number of parts in order to tilt a seat forward relative to a support base. Therefore, a chair having the following structure is expected to appear: in the case of a chair in which the assembly seat is tilted forward with respect to the support base, management of parts related thereto, handling at the time of assembly, and the like are facilitated.

The same applies to the above case not only in the structure in which the seat can be tilted forward with respect to the support base but also in the case of the structure in which the seat can be tilted backward with respect to the support base.

Patent document 1: japanese patent laid-open publication No. 2014-90996

Disclosure of Invention

The present invention has been made in view of the above circumstances, and provides a chair including: the seat moves in a tilting motion with respect to the support base, with a structure facilitating the management and/or handling of its associated parts when assembled.

That is, the present invention has the following configuration.

A chair according to claim 1 is a chair in which a seat is supported by a support base via a coupling member, wherein: interposing a seat tilt movement adjusting unit for adjusting a degree of tilt of the seat with respect to the support base between the support base and the seat; the seat tilt movement adjusting unit is assembled to the base and can be integrally handled with the base; the base is attached to one of the seat and the support base, and supports the coupling member on the other side such that a distance between the coupling member and the seat or the support base can be changed.

In the chair according to claim 2, in the configuration according to claim 1, the seat reclining movement adjustment means includes: the base mounted directly or indirectly to the seat; a lock member held by the base and movable between a lock position for restricting movement of the base relative to the support base and an unlock position for allowing movement of the base relative to the support base; and a drive mechanism which is held by the base and moves the lock member between the lock position and the unlock position in response to an operation applied from the outside.

In the chair according to claim 3, in the configuration according to claim 1, the seat reclining movement adjustment unit includes: the base mounted directly or indirectly to the support base; a lock member held by the base and movable between a lock position for restricting movement of the base relative to the seat and a lock release position for allowing movement of the base relative to the seat; and a drive mechanism which is held by the base and moves the lock member between the lock position and the unlock position in response to an operation applied from the outside.

A chair according to claim 4, wherein in the structure according to claim 1, 2 or 3, the coupling member is a shaft-like member held by the support base; the seat tilt movement adjustment unit includes: a base provided with a guide portion having a space for guiding the connecting member to be movable up and down; a lock member held by the base and movable between a lock position where the lock member protrudes into the space to restrict movement of the coupling member and a lock release position where the lock member is retracted from the space to allow an up-and-down movement of the coupling member; and a drive mechanism which is held by the base and moves the lock member between the lock position and the unlock position in response to an operation applied from the outside.

In the chair according to claim 5, in the configuration according to claim 2, 3 or 4, the drive mechanism includes: a link member linked with the locking part; and an operation lever for applying an operation force to the link member.

In the chair according to claim 6, in the configuration of claim 4 or 5, the seat reclining movement adjusting means includes a pair of the lock members that are engaged with both left and right sides of the connecting member, respectively, and the driving mechanism causes both the lock members to be interlocked by an operating force applied to a single operating lever.

As described above, according to the present invention, it is possible to provide a chair in which a seat is tilted with respect to a support base, and which has a structure in which management of related parts and/or handling at the time of assembly are facilitated.

Drawings

Fig. 1 is a perspective view showing an embodiment of the present invention.

Fig. 2 is a left side view of the embodiment.

Fig. 3 is a rear view of the embodiment.

Fig. 4 is a plan view of the embodiment.

Fig. 5 is an exploded perspective view of the embodiment.

Fig. 6 is an exploded perspective view of the embodiment.

Fig. 7 is an exploded perspective view of the embodiment.

Fig. 8 is a perspective view of the embodiment.

Fig. 9 is an enlarged partial sectional view taken along line a-a of fig. 3.

Fig. 10 is a cross-sectional view corresponding to fig. 9 showing a state in which the seat is in a forward tilted posture.

Fig. 11 is a partially enlarged perspective view of the embodiment.

Fig. 12 is a side view for explaining the operation of the seat forward tilting unit of this embodiment.

Fig. 13 is a side view for explaining the operation of the seat forward tilting unit of this embodiment.

Fig. 14 is a side view for explaining the operation of the seat forward tilting unit of this embodiment.

Fig. 15 is a plan view for explaining the operation of the seat forward tilting unit of the embodiment.

Fig. 16 is a plan view for explaining the operation of the seat forward tilting unit of the embodiment.

Fig. 17 is an exploded perspective view of the embodiment.

Fig. 18 is a front view of the embodiment.

Fig. 19 is a sectional view taken along line B-B of fig. 18.

Fig. 20 is a cross-sectional view taken along line C-C of fig. 18.

Fig. 21 is an exploded perspective view of the embodiment.

Fig. 22 is a sectional view taken along line D-D of fig. 3.

Fig. 23 is an exploded perspective view showing the armrest.

Description of the reference numerals

2 … supporting base

3 … seat

B … base (first part)

F … front axle (connecting component)

L1 … locking part (second part)

L2 … driving mechanism

L21 … Link member (first Link member)

L22 … Link Member (second Link Member)

L23 … operating lever

N … Long hole (guide part)

U … seat forward adjusting unit (seat tilting motion adjusting unit)

(v) … locked position

(w) … unlocked position

Detailed Description

An embodiment of the present invention applied to an office swivel chair C having a synchronization lock mechanism R will be described below with reference to fig. 1 to 23.

The chair C is a chair in which armrests 6 are attached to a chair main body C1.

The chair main body C1 includes: a chair leg 1; a support base 2 supported on the upper portion of the leg 1 and capable of horizontally rotating; a seat 3 supported by the support base 2; and a backrest 5 supported by the support base 2 via a seatback frame 4 so as to be able to tilt backward.

The chair main body C1 is formed by supporting the seat 3 and the backrest 5 on the support base 2 so as to be able to tilt, and is configured not only as follows: the seat 3 and the backrest 5 are operated in synchronization with each other by the action of the synchronization lock mechanism R, so that a standard posture (S) and a reclining chair (reclining) posture (L) as shown in fig. 2 can be achieved, and in this embodiment, the seat is further configured such that: the seat 3 can be tilted independently of the movement of the backrest 5 between a standard position (a) shown in fig. 9 and a forward tilting position (B) shown in fig. 10 by the action of a seat forward tilting unit G described later.

< chair leg 1 >

The above-described chair leg 1 is configured to include: a leg base B11 of a leg-branch type having casters; and a leg stay 12 erected at the center of the leg base B11. The leg stay 12 is a general member mainly composed of a gas spring, and the support base 2 is attached to an upper end portion of the leg stay 12.

< support base 2 >

The support base 2 is supported by the legs 1 so as to be horizontally rotatable and vertically liftable, and includes: a cover 21 attached to the leg stay 12; a main shaft 22 penetrating through both side walls 211 of the housing 21 for supporting the backrest 5; a synchronizing frame 23 provided to be rotatable about the main shaft 22, and including a reaction force receiving shaft 231 at a 1 st rotation end and a mounting portion 232 for mounting the seatback frame 4 at a 2 nd rotation end; and a tilting reaction force generation mechanism 24 for generating an elastic repulsive force with respect to the tilting movement of the backrest 5 by urging the reaction force receiving shaft 231 of the synchronization frame 23.

Long holes 212 are formed in the front end portions of the both side walls 211 of the cover 21, and the long holes 212 support a front shaft F as a front coupling member described later so as to be slidable in the front-rear direction.

The synchronization frame 23 includes: a pair of plate-shaped synchronizing frame bodies 233 provided on both sides of the housing 21; the reaction force receiving shaft 231 connecting the 1 st rotation ends of the left and right synchronizing frame bodies 233 to each other; the mounting portion 232 extending outward and provided at the 2 nd rotation end of each of the synchronizing frame bodies 233; a shaft holding portion 234 extending upward from an intermediate portion of each of the synchronizing frame bodies 233; and a rear shaft 235 as a coupling member supported by the two shaft holding portions 234 and connected to the rear. A screw hole is formed in the attachment portion 232, and a back stay 41 of a back frame 4, which will be described later, is fixed to the synchronizing frame 23 by a bolt v1 screwed into the screw hole.

The tilt reaction force generation mechanism 24 is configured to be able to apply an elastic repulsive force to the reaction force receiving shaft 231 of the synchronization frame 23 by using a coil spring 241, and is a normal mechanism, and therefore, a detailed description thereof will be omitted.

< seat 3 >

The seat 3 includes: a housing 31 disposed on the support base 2; and a seat main body 32 having an inner case 321 provided on the outer case 31. Between the outer shell 31 and the inner shell 321 are provided: a slide guide mechanism 33 for slidably moving the inner case 321 in the front-rear direction with respect to the outer case 31; and a slide positioning mechanism 34 for moving the inner case 321 to a desired slide position and locking it.

The housing 31 has a plurality of reinforcing ribs on its upper surface, and has a mounting window 311 in the center of its front end for mounting a base B of a seat forward-tilting unit G, which will be described later. The housing 31 has a shaft support portion 312 projecting from the lower surface side of the rear end portion to rotatably support both end portions of the rear shaft 235.

The seat main body 32 includes: an inner case 321 disposed on the outer case 31 and slidably movable in the front-rear direction by a slide guide mechanism 33; a buffer 322 disposed on the inner case 321; and a seat skin material 323 surrounding the cushion member 322 and the lower surface of the peripheral edge portion of the inner case 321.

The inner case 321 is a substantially rectangular member formed of resin and having a plurality of slits 324 in a plan view. The inner case 321 is disposed to be slidably movable in the front-rear direction within a predetermined range with respect to the outer case 31 via the slide guide mechanism 33.

The slide guide mechanism 33 is configured to be capable of sliding the inner case 321 in the front-rear direction with respect to the outer case 31 by engaging sliders, not shown, attached to the outer case 31 with guide grooves 325 for sliding formed at a plurality of locations on the inner case 321. The inner case 321, which is guided by the slide guide mechanism 33 to slide in the front-rear direction, is locked at a desired slide position by the slide positioning mechanism 34.

The slide positioning mechanism 34 includes: an operation member 341 capable of moving up and down; and a plurality of positioning engaging portions 342 that selectively correspond to the operating member 341 as the inner case 321 slides. That is, in a state where the operation member 341 supported by the housing 31 is operated upward, the seat main body 32 is moved forward and backward with respect to the housing 31, and the hand is separated from the operation member 341 and lowered, whereby the operation member 341 is engaged with the engaging portion 342 of the housing, and the seat main body 32 can be locked at a desired position.

The cushion material 322 is a member in which a nonwoven fabric is attached to the lower surface of molded polyurethane, for example. The cushion material 322 is placed on the upper surface of the inner case 321, and is surrounded by the seat skin material 323 made of cloth or the like together with the peripheral edge portion of the inner case 321.

The seat 3 described above has a front portion supported by the support base 2 via the front shaft F as a front coupling member and a rear portion supported by the support base 2 holding the rear shaft 235 as a rear coupling member, and a seat forward tilting unit G for adjusting a forward tilting degree of the seat 3 with respect to the support base 2 in distinction to a tilting movement of the backrest 5 is provided between the front portion of the seat 3 and the support base 2.

< seat forward tilting unit G >

The seat forward-tilting unit G includes a front shaft F as the coupling member for coupling the front portion of the support base 2 and the front portion of the seat 3, and is configured to be capable of selectively switching the coupling positions by changing the coupling positions of the seat 3 and the front shaft F to change the height of the front portion of the seat 3 from the ground surface, thereby tilting the entire seat 3 forward. In this embodiment, in the base B which is movable up and down integrally with the seat 3, two coupling positions, a first coupling position where the front shaft F is positioned below the lock member L1 and a second coupling position where the front shaft F is positioned above the lock member L, can be selectively achieved.

Here, the first coupling position is a position shown in fig. 9, and fig. 11 to 13, and the second coupling position is a position shown in fig. 10 and fig. 14.

Specifically, the chair C according to this embodiment can rotate the front portion of the seat 3 downward by rotating the rear portion of the seat 3 as a center. The seat forward tilting unit G can maintain the front axle F at a specific position and can move the front axle F relative to the seat 3 by changing the positional relationship between a base B, which will be described later, and a lock member L1, which are a plurality of parts engaged with the front axle F.

In this embodiment, the plurality of components are: a base B having, as a first component, a vertically long hole N for holding the front shaft F so as to be capable of a plurality of coupling positions; and a lock member L1 provided as a second component so as to be able to protrude into and retract into the elongated hole N, and configured to lock the front shaft F in a protruding state so as not to move from a specific coupling position, and to enable the front shaft F to move along the elongated hole N in a retracted state.

In the chair C of this embodiment, the seat 3 moves rearward following the backward tilting when the backrest 5 tilts backward by the action of the synchronization lock mechanism R, and the front shaft F can move forward and backward relative to the support base 2 while changing its vertical position relative to the seat 3. In other words, a long hole 212 is provided in the front portion of the support base 2 as a sliding portion in the front-rear direction for guiding the front shaft F, and a vertical position changing portion for changing the vertical relative position of the front shaft F with respect to the support base 2 is provided in the front portion of the seat 3. The vertical position changing unit is mainly configured by a long hole N provided in the base B and a lock member L1 held by the base B so as to be capable of protruding into and retracting from the long hole N.

More specifically, the seat forward-tilting unit G includes a lock mechanism L that performs locking by changing a distance between the seat 3 and the support base 2 by acting on the front shaft F that connects the seat 3 and the support base 2, and performs locking by changing a distance between the seat 3 and the support base 2.

Namely, the seat forward tilting unit G includes: a base B attached to the housing 31 of the seat 3 and movable up and down with respect to the front shaft F; the lock mechanism L provided on the base B and locking a position of the front shaft F with respect to the base B to a desired position; and a biasing element E for elastically biasing the base B upward with respect to the support base 2.

The base B has a long hole N as a vertical guide portion and a space capable of guiding the front shaft F to move up and down. Specifically, the base B includes: a base body B1 disposed at the front end of the support base 2 and having a top wall B11, a front wall B12, a rear wall B13, and block-shaped left and right side walls B14 having a multiple-wall structure; mounting flange portions B15, B16 provided on the front wall B12 and the rear wall B13 of the base body B1 and having bosses (boss) B151, B161 through which bolts v4 are inserted; a first link pivot portion B17 provided at one end side in the left-right direction of the front wall B12 of the base body B1; a second link pivot portion B18 provided on the other end side in the left-right direction of the front wall B12; and a connecting pivot guide B19 provided at the center of the front wall B12. The left and right side walls B14 are formed with the long holes and with a recessed portion B141 communicating with the vertical center portion of the long hole N for accommodating the lock member.

The lock mechanism L includes: the front shaft F; the locking member L1 provided in the recessed portion B141 of the base B and movable between a locking position (v) protruding into a space formed by the elongated hole N to restrict the vertical movement of the front axle F and a lock release position (w) retracted from the space to allow the vertical movement of the front axle F; and a drive mechanism L2 for operating the lock member L1 between the lock position (V) and the unlock position (W) in response to an operation applied from the outside.

The lock mechanism L in this embodiment includes a pair of lock members L1 directly engaged with each of the left and right sides of the front axle F, and the lock members L1 arranged in a left-right pair are interlocked by an operating force applied to the operating lever L23 as a single operating unit by the drive mechanism L2. The lock member L1 is a block member having an L-shape in side view.

The drive mechanism L2 includes: a first link member L21 having a base end portion thereof pivotally supported at a first link pivot portion B17, which is one of left and right side portions on the front side of the base B, and a tip end portion thereof positioned at the other side portion on the front side of the base B; a second link member L22 having a base end portion thereof pivotally supported at a second link pivot portion B18 which is the other of the left and right sides of the front side of the base B and a tip end portion thereof positioned at one side portion of the base B; and a pivot member L24 that pivots an intermediate portion of the second link member L22 to an intermediate portion of the first link member L21. The driving mechanism L2 has one locking element L1 coupled to the distal end portion of the first link member L21 via a coupling pin p1, and has the other locking element L1 coupled to the distal end portion of the second link member L22 via a coupling pin p 1. The vertically intermediate portion of the pin p1 is disposed so as to be movable forward and backward in a communication path B142 extending in the vertical direction and communicating the lower surface side of the side wall B14 of the base B with the recessed portion B141. The pivot member L24 can be moved forward and backward while being guided by the pivot shaft guide B19 for connection of the base B.

An operating lever L23 is integrally provided at a distal end of the first link member L21, and by operating the operating lever L23 to pivot the first link member L21, the locking member L1 connected to one end of the first link member L21 is moved forward and backward between the locking position (v) and the unlocking position (w). Further, since the movement of the first link member L21 is transmitted to the central portion of the second link member L22 via the pivot unit L24, the other locking member L1 connected to the second link member L22 can also be operated between the locking position (v) and the unlocking position (w) in synchronization with the one locking member L1.

The force application element E comprises: a first spring holder E1 rotatably attached to a central portion of the front axle F; a second spring holder E2 turnably engaged with the front wall B12 of the base B; and a compression coil spring E3 interposed between the two spring holders E1 and E2 as urging means, wherein the urging element E elastically urges the front portion of the seat 3 upward via the base B with the front shaft F supported by the support base 2 as a stand-off point.

A part of the seat forward tilting unit G as described above is configured to be integrally handled as a seat forward tilting adjustment unit U which is a seat tilting movement adjustment unit.

The seat forward tilting adjustment unit U is interposed between the support base 2 and the seat 3, and adjusts the degree of tilting of the seat 3 with respect to the support base 2. The seat forward tilting adjustment unit U is assembled to the base B so as to be integrally handled, and is configured to be able to change a distance between the support base 2 and the seat 3 while mounting the base B to the seat 3 and supporting the front axle F.

Specifically, the seat forward tilting adjustment unit U includes: the base B; the lock member L1, which is held by the base B and is movable between a lock position (v) for restricting the movement of the base B with respect to the support base 2 and a lock release position (w) for allowing the movement of the base B with respect to the support base 2; and the driving mechanism L2 held by the base B and capable of moving the lock member L1 between a lock position (v) and an unlock position (w) in response to an operation applied from the outside.

Further, the rotation center of the rear portion of the seat 3 is a rear shaft 235 connecting the seat 3 and the support base 2 at the rear side. By using the rear shaft 235 as the rotation center of the seat 3, the distance between the backrest point and the seat 3 is not easily changed. Therefore, even if the seat 3 is brought into the forward-inclined posture (B), the seating comfort of the seated person is suppressed from being adversely affected. In the chair C capable of reclining and locking, the rear shaft 235, which is an essential structure, is used as a rotation center of the rear portion of the seat 3. Therefore, in the chair C capable of backward tilting locking, it is possible to relatively easily select whether or not the seat 3 can be tilted forward simply by attaching and detaching the seat forward tilting adjustment unit U disposed in front of the seat 3 and/or the support base 2.

< chair back frame 4 >

The seatback frame 4 includes: left and right back stays 41 for supporting the proximal end portion by the support base 2; and link members 42 connecting the distal end portions of the left and right back stays 41 to each other. The left and right back stays 41 are opened inward and are integrally formed by, for example, aluminum die casting and/or reinforced plastic. The back stay 41 includes: a back stay main body 411 having an L-shaped side view; left and right backrest mounting portions 412 integrally provided at the distal ends of the respective back stay main bodies 411 and extending outward while gradually rising; and left and right connection parts 413 integrally provided at the distal ends of the back stay bodies 411 and extending inward, respectively, wherein the left and right connection parts 413 are connected to each other by the link member 42.

The base end of each back stay main body 411 has a boss portion 414 fitted to the end of the main shaft 22, and an intermediate rib 415 fixed to the mounting portion 232 of the synchronizing frame 23 by a bolt v1 is provided near the base end. The left and right back stay bodies 411 are rotatably attached to the support base 2 by stopping the intermediate rib 415 with respect to the attachment portion 232 of the synchronizing frame 23 by a bolt v1 in a state where the boss portion 414 is fitted to the main shaft 22.

The backrest mounting portion 412 located on the distal end side of the backrest stay main body 411 is formed in a shape along the lower edge of the lower frame 51b of the backrest 5, and has a joining end surface 412a facing upward at the peripheral edge portion of the upper surface thereof, and a convex portion 412b projecting upward for mounting the backrest 5 at the inner portion surrounded by the joining end surface 412 a. The left and right backrest mounting portions 412 are provided with bolt insertion holes 412c through which bolts v2 for fixing the backrest 5 are inserted.

The connection portion 413 located at the distal end side of the back stay main body 411 is formed continuously to the back attachment portion 412, and the left and right connection portions 413 are butted against each other at the center position in the left-right direction of the chair C. That is, the seatback frame 4 is a member in which the right back stay 41 disposed on the right side of the support base 2 and the left back stay 41 disposed on the left side are butted against each other in the left-right direction at a turning end portion located on the rear end side, and the left and right back stays 41 are joined to each other in an assembled state. The left and right connection portions 413 have recesses 413a opened to the facing end surfaces and the front surface, and the metal link member 42 is housed in the recesses 413 a. Screw holes 421 are formed in both end portions of the link member 42, and bolt insertion holes, not shown, are bored in portions of the respective connection portions 413 corresponding to the screw holes. Then, the left and right back stays 41 are integrally connected by screwing the coupling bolt v3 inserted through the bolt insertion hole into the screw hole 421 of the link member 42. A bearing bracket 43 is integrally provided at a center portion in the left-right direction on the front edge side of the link member 42, and a tip end portion of the gas spring 44 is rotatably connected to the bearing bracket 43. That is, the gas spring 44 is for giving a rising force to the seatback frame 4, and has a front end portion thereof pivoted to the support base 2 and a rear end portion thereof pivoted to the seatback frame 4. In addition, the gas spring 44 also functions to lock the backrest 5 in a desired reclined position by a lever operation.

< backrest 5 >

The backrest 5 includes: a backrest support member 51 having a frame shape and referred to as a so-called backrest frame; a tension member 52 which is net-shaped, is provided in tension to the backrest support member 51, and receives the load of the seated person; and a lumbar support device W provided to the backrest support member 51, wherein the backrest 5 is attached to the seatback frame 4.

The backrest support member 51 is a member integrally molded from a synthetic resin, and includes: left and right side frames 51 a; a lower frame 51b for connecting the lower ends of the side frames 51 a; and an upper frame 51c for coupling upper ends of the side frames 51a to each other.

Each of the side frames 51a has a bent portion 510 that protrudes forward most at a portion corresponding to the waist of the seated person, and the bent portion 510 has a shape of "く" in side view. The bent portion 510 is provided with mounting recesses Q1, Q2 for mounting the wood support m.

The right-side attachment recess Q1, which is one of the attachment recesses, is formed between the inner wall Q11 and the outer wall Q12 and is open forward, and a hollow shaft Q14 is provided projecting forward from the center in the vertical direction of the rear wall Q13. A plurality of notches Q111 for allowing a strip-like body m1, which is a pressure receiving body of a wood brace m to be described later, to pass through are formed at the front edge of the inner wall Q11 at predetermined intervals in the vertical direction.

The other mounting recess, i.e., the mounting recess Q2 on the main apparent left side, is formed between the inner wall Q21 and the outer wall Q22 and is open forward, and a bearing Q24 is formed at the center in the vertical direction of the rear wall Q23. A plurality of notches Q211 for allowing a strip-shaped body m1, which is a pressure receiving body of a wood brace m to be described later, to pass through are formed at the front edge of the inner wall Q24 at predetermined intervals in the vertical direction.

The lower frame 51b has a joint end surface 511 at a peripheral edge portion of a lower surface thereof, the joint end surface being opposed to the joint end surface 412a of the seatback frame 4, and a recess 512 at an inner portion surrounded by the joint end surface 511. The lower frame 51b has left and right end portions formed with cap bolts 513 opened to the front side and recessed, and nuts 514 are accommodated in the left and right cap bolts 513. Further, a bolt insertion hole 515 corresponding to the nut 514 disposed in the cap bolt 513 is provided in a state of communicating with the lower surface.

In this embodiment, the concave portion 512 provided at the lower end of the seatback 5 as a first member is engaged with the convex portion 412b of the seatback frame 4 as a second member, and the seatback 5 and the seatback frame 4 are joined with a space between the first joining end surface 511 of the seatback 5 and the second joining end surface 412a provided at the pivot end of the seatback frame 4. Further, between the first joint end surface 511 and the second joint end surface 412a, there is a feature member H which can cover the base end portion of the convex portion 412b of the seatback frame 4 and has a cushioning effect in a state of being sandwiched by the first joint end surface 511 and the second joint end surface 412 a.

The tension member 52 is a net member that receives the load of the seated person. Specifically, the tension member 52 is installed in a tensioned state in the frame-shaped backrest support member 51 by inserting and fixing the left and right edges into the mounting grooves mz of the side frame 51a, inserting and fixing the lower edge into the mounting grooves mz of the lower frame 51b, and inserting and fixing the upper edge into the mounting grooves mz of the upper frame 51 c.

The lumbar support device W is mainly composed of left and right side frames 51a of the backrest 5 and the wood support m attached to the left and right side frames 51 a.

The wood support m includes: a band-shaped body m1 as a pressure receiving body, which extends in the left-right direction, receives the load of the sitting person, bends, and can elastically deform; and left and right side edge bodies m2, m3 formed integrally with the belt-like body m1 at left and right side edges of the belt-like body m1 and having high rigidity. Further, the lumbar support device W includes: a deflection distribution mechanism d for making the deflection degrees of at least the upper side region ur and the lower side region sr of the belt-like body m1 different from each other when a load from a seated person acts; and a flexure adjusting mechanism j for adjusting the degree of flexure of the entire strip m 1.

The wood support m is integrally provided with the band-shaped body m1 and the left and right side edge bodies m2 and m3, and is integrally molded from a synthetic resin in this embodiment.

A plurality of the above-described pressure receiving members, i.e., the belt-like bodies m1, are arranged at intervals in the vertical direction. In this embodiment, 6 strip-shaped bodies m1 having substantially the same vertical width are arranged at substantially equal intervals in the vertical direction. One end of each of the strips m1 is integrally connected to the inner edge of one of the side edges m2, and the other end of each of the strips m1 is integrally connected to the inner edge of the other of the side edges m 3.

One of the side edge bodies, i.e., the right side edge body m2 located on the right side in the front view, is a substantially elongated diamond-shaped member extending in the vertical direction, and includes a bearing hole m21 in the vertical center portion. Specifically, the right edge body m2 includes a front plate m22 continuous with the band-like body m1, and a bulging portion m23 protruding in a rhombus shape from the rear of the front plate m 22. The bulging portion m23 includes: inner longitudinal ribs m24 meandering so that the vertically central portion is positioned innermost; an outer longitudinal rib m25 meandering so that the center portion in the up-down direction is positioned outermost; and a plurality of transverse ribs m26 connecting the inner longitudinal rib m24 and the outer longitudinal rib m 25. The bearing hole m21 opened rearward is formed by the center portions in the vertical direction of the inner vertical rib m24 and the outer vertical rib m25 constituting the bulging portion m23 and the lateral rib m26 formed in the vicinity of the center in the vertical direction. The position of the side surface m241 of the inner longitudinal rib m24 facing the center direction of the chair C substantially coincides with the position of the inner edge of the front plate m22 in front view. The deflection distributing mechanism d is configured mainly by the right side edge body m2 and the side frame 51a corresponding to the side edge body m 2.

The other side edge body, i.e., the left side edge body m3 located on the left side in the front view, is a front view short booklet-like member extending in the up-down direction, and has a wedge shape in a plan view cross section. In other words, the left edge body m3 is set such that the thickness dimension of the outer edge side is larger than the thickness dimension of the inner edge side in the front-rear direction, the front surface is continuous with the front surface of the belt-like body m1 to be substantially the same plane, and the rear surface m3a is inclined with respect to the front surface. Specifically, the side edge body m3 includes: a front plate m31 continuous with the strip m1 and forming the front surface; and a plurality of ribs m32 provided at intervals in the vertical direction so as to protrude from the rear side of the front plate m31, wherein the side edge body m3 has an inclined rear surface m3a formed at the rear end of each rib m 32. The deflection adjusting mechanism j is configured by using the left side edge body m3 and the side frame 51a corresponding to the side edge body m3 as components.

The wood brace m is set such that the dimension in the left-right direction of the strip m1 present in the upper region ur and the strip m1 present in the lower region sr is slightly longer than the strip m1 present in the middle region cr.

The flexure distributing mechanism d supports the vertically intermediate portion of the one side edge body m2 on the corresponding one side frame 51a so as to be rotatable in the left-right direction. That is, the wood brace m is placed between the left and right side frames 51a, and the one side edge m2 is received in the attachment recess Q1 of the one side frame 51 a. A shaft Q14 projecting from the attachment recess Q1 is engaged with the bearing hole m21 of the side edge body m2, and the side edge body m2 is held so as to be rotatable about the axis of the shaft Q14. The strip-shaped bodies m1 of the wood brace m are inserted into the notches Q111 provided in the inner wall Q11 of the right mounting recess Q1. The mounting recess Q1 is covered with a cover Q3, and the forward movement of the side edge body m2 is restricted by the cover Q3. In this way, the deflection distribution mechanism d supports the one side edge body m2 of the wood support m to the side frame 51a of the backrest 5 so as to be rotatable in the right-left direction. The deflection distribution mechanism d can adjust the degree of deflection of the upper region ur and the lower region sr of the wood support m by causing the side edge body m2 supported by the side frame 51a to perform a scale operation around the axis Q14 as a rotation center in accordance with a load from a seated person acting on the wood support m.

The flexure adjusting mechanism j is for adjusting the degree of flexure of the entire strip m1, and includes: a restricting member j1 provided on the corresponding main apparent left side frame 51a and restricting the movement of the corresponding side edge member m3 in the left-right direction; and a restriction position changing unit j2 that changes the restriction position restricted by the restriction member j 1.

The regulating member j1 is a vertically elongated rod-shaped member that is bent along the shape of the bent portion 510 of the side frame 51a, and is disposed between the side edge body m3 of the wood support m housed in the mounting recess Q2 and the back wall Q23 of the mounting recess Q2. The regulating member j1 includes a boss portion j12 for holding the nut j11 at the vertical center thereof. The front surface j1a of the regulating member j1 is inclined so as to gradually recede from the inner edge toward the outer edge, and the back surface of the side edge body m3 abuts on the front surface.

The restricted position changing means j2 includes: a front cover Q4 which covers the mounting recess Q2 of the side frame 51a and prevents the side edge body m3 of the wood support m disposed in the mounting recess Q2 from moving forward; a screw bar j21 as a screw feeding means, supported by a bearing Q24 provided on the back surface wall Q23 of the mounting recess Q2, and screwed to the nut j 11; and an adjustment knob j22 provided at the rear extension end of the screw bar j21 for rotating the screw bar j21 to advance and retreat the regulating member j1 by screwing in the front and rear directions. That is, the regulating position changing means j2 forms a tapered space whose width gradually decreases toward the center of the chair C by the back surface Q41 of the lid Q4 and the front surface j1a of the regulating member j1, and a side edge m3 of the wood support m having a wedge shape in a plan sectional view is disposed in the tapered space. The movement of the side edge body m3 moving inward can be restricted to a predetermined position by the wedge action of the tapered space, and the movement of the limiting position changing means j2 can restrict the movement of the side edge body m3 moving inward by the load of the sitting person acting on the wood support m. That is, the regulating position changing means j2 can change the front-rear width of the tapered space to change the regulating position of the side edge body m3 by changing the front-rear position of the regulating member j1 that houses the nut j11 by moving the nut j11 screwed to the screw rod j21 forward and backward by adjusting the operation of the knob j 22.

< feature part H >

The feature member H is an annular member integrally formed of a synthetic resin, and is fitted around the base end portion of the projection 412b of the seatback frame 4. The feature member H has an outer surface H1 continuous with the outer surface of the seatback frame 4, i.e., the back surface of the seatback attachment portion 412, and the outer surface of the seatback 5, i.e., the back surface of the lower frame 51b, to be substantially flush with each other. The outer surface of the feature member H can be colored arbitrarily, and also serves to improve the design of the entire chair C by giving a striking impression visually or the like.

Here, if an example of an assembly procedure related to the feature component H is schematically described, the following is made. First, in a state where the left and right back stays 41 are butted against each other, the feature member H is fitted to the convex portions 412b of the left and right back stays 41 to temporarily position the left and right back stays 41. Next, in the temporarily positioned state, the two back stays 41 are connected by the link member 42, thereby completing the seatback frame 4. Then, the convex portion 412b of the seatback frame 4 is engaged with the concave portion 512 of the seatback 5, and the bolt v2 inserted from below through the bolt insertion holes 412c and 515 is screwed into the nut 514 of the seatback 5, whereby the seatback 5 is fixed to the seatback frame 4. In this assembled state, the above-described feature member H is sandwiched and fixed between the joint end surface 412a of the seatback frame 4 and the joint end surface 511 of the seatback 5, and its outer surface H1 continues to be flush with the outer surfaces of the seatback frame 4 and the seatback 5. In this assembled state, the feature member H is disposed so as to pass through the joint portion 413c of the left back stay 41 and the right back stay 41, and is shielded from the outside so that a part of the joint portion 413c extending in the vertical direction formed by abutting the left and right back stays 41 is not visible.

In addition, inclined surfaces H21 and H31 are provided on portions of the upper surface H2 and the lower surface H3 of the feature member H, the inner edge side of which is projected more than the outer edge side thereof, and a corresponding inclination is formed on a joint end surface of the backrest 5 and the seatback frame 4 which is in contact with the upper surface H2 and the lower surface H3. That is, when the backrest 5 is fastened to the seatback frame 4 by the bolt v2, the feature member H is positioned and fixed at a desired position by the tapered action of the inclined surfaces H21 and H31 and the engagement end surfaces 511 and 412 a.

The backrest 5 and the seat 3 having the above-described structure are tilted in a predetermined ratio by the synchrolock mechanism R.

< synchronous locking mechanism R >

The synchrolock mechanism R supports the front shaft F held by the base B on the support base 2 so as to be movable forward and backward, supports the rear shaft 235 held by the synchro frame 23 on the housing 31 of the seat 3, and links the backward tilting operation of the backrest 5 and the sinking operation of the seat 3. That is, the synchrolock mechanism R is provided by linking the seat 3 to the front end portion of the support base 2 via the front shaft F so as to be movable forward and backward, and supports the rear end side of the seat 3 to the support base 2 via the rear shaft 235. Specifically, the front shaft F is held slidably in the front-rear direction by a long hole 212 extending in the front-rear direction provided at the front end portion of the support base 2. The rear shaft 235 also serves as a pivot stand point of the seat forward tilting unit G, and is supported by the bearing portion 234 of the synchronizing frame 23. The synchronizing frame 23 supporting the base 2 is configured to be rotatable relative to the cover 21, and the rear shaft 235 held by the synchronizing frame 23 is configured to be movable integrally with the seatback frame 4 supporting the seatback 5.

< armrest 6 >

The armrest 6 is attached to a seat 3, and the seat 3 can be tilted between a standard position (a) and a forward tilting position (B) by the operation of the seat forward tilting unit G. The armrest 6 includes an elbow contact 62 having the elbow contact surface 62m on the upper surface, and the elbow contact surface 62m includes a first elbow contact surface portion 62m1 and a second elbow contact surface portion 62m 2. When the seat 3 is located at the standard position (a) shown by the solid line in fig. 2 and fig. 9, the first toggle contact surface portion 62m1 is closer to the horizontal than the second toggle contact surface portion 62m2, and when the seat 3 is located at the forward tilting position (B) shown in fig. 10, the second toggle contact surface portion 62m2 is closer to the horizontal than the first toggle contact surface portion 62m 1. The elbow contact surface 62m is arranged such that the second elbow contact surface portion 62m2 is continuously located behind the first elbow contact surface portion 62m 1. In fig. 9 and 10, a line indicated by a solid line 62ma is an upper surface reference line corresponding to the front-rear direction center position of the first elbow contact surface 62m1, and a line indicated by a one-dot chain line 62mb is an upper surface reference line corresponding to the front-rear direction center position of the second elbow contact surface portion 62m 2. In fig. 10, a line indicated by a broken line sh is a horizontal line.

Specifically, the armrest 6 is held by an elbow frame 6b attached to the seat 3 so that the armrest body 6a can be changed in the vertical position.

The elbow frame 6b is an integrally molded product including: a mounting arm 64 having a base end portion mounted to the lower surface of the housing 31 by a screw v 5; and a cylindrical portion 63 held at the intermediate position (c) at the distal end of the mounting arm 64. The tubular portion 63 accommodates a lifting position adjusting mechanism for changing the lifting position of the armrest body 6a by operating a lifting operation button 613 disposed on the elbow strut 61, but the lifting position adjusting mechanism is not illustrated and is a normal member, and therefore, the description thereof will be omitted.

The armrest body 6a includes: an elbow stay 61 held by the cylindrical portion 63; and an elbow contact 62 attached to an upper end portion of the elbow strut 61, wherein an elbow contact guide mechanism 66 is provided between the elbow strut 61 and the elbow contact 62, and the elbow contact guide mechanism 66 guides the elbow contact 62 so that the elbow contact 62 advances and retreats between a most advanced position (f) and a most retreated position (r) through an intermediate position (c), and rotates the elbow contact 62 in the vicinity of the intermediate position (c) in conjunction with the advancing and retreating.

The elbow strut 61 includes: an elbow strut main body 611 held by the cylindrical portion 63; and an elbow contact support portion 612 provided at an upper end portion of the elbow strut main body 611. The toggle contact support portion 612 has the toggle contact guide mechanism 66 mounted on the upper surface thereof, and includes a recessed portion 612a that is open to the front and the inner side.

The toggle contact 62 includes: an elbow rest 621; and an elbow pad 622 provided on the elbow support 621 and mainly composed of a cushion member.

The elbow support member 621 includes: a bottom wall 621a reinforced by a rib supporting the elbow pad 622 from the lower side; and a peripheral edge 621b that protrudes upward from the peripheral edge of the bottom wall 621a and that wraps the peripheral edge portion on the lower surface side of the elbow pad 622. The peripheral edge 621b is a member that rises from an end edge portion of the bottom wall 621a, and has a shape that can be seen from the outside to substantially keep the vertical width of the elbow pad 622 constant.

The elbow pad 622 is configured such that the thickness dimension of the portion corresponding to the first elbow contact surface portion 62m1 is set to be greater than the thickness dimension of the portion corresponding to the second elbow contact surface portion 62m 2. Therefore, the protruding dimension of the peripheral edge 621b corresponding to the first toggle contact surface portion 62m1 is set to be larger than the protruding dimension of the second toggle contact surface portion 62m 2.

The toggle contact guide mechanism 66 is configured to guide the toggle contact 62 so that the toggle contact 62 performs a forward and backward movement between a most advanced position (f) and a most retracted position (r) via an intermediate position (c) and rotates the toggle contact 62 in the vicinity of the intermediate position (c) in conjunction with the forward and backward movement, and the toggle contact 62 is configured to assume a forward posture in the forward and backward directions at the most advanced position (f) and the most retracted position (r) and an inward posture in which a position of a tip end is positioned innermost at the intermediate position (c).

Specifically, the toggle contact guide mechanism 66 includes: a grub bolt 661 provided as a first connecting portion to the elbow contact supporting portion 612; a rail 665 which is provided on the elbow member 621 and can guide the grub bolt 661 to slide in the front-rear direction; a tack bolt 663 as a second connecting portion provided to the elbow member 621; and a link member 664 that is provided to the toggle contact support 612 so as to be horizontally rotatable and has a rotating end pivotally connected to the flat head bolt 663 as the second connecting portion.

Specifically, the grub bolt 611 as the first coupling portion is screwed into the nut portion 612 of the elbow contact support portion 612. The rail 665 is a groove member extending in the front-rear direction, and is formed through the bottom wall 621a of the elbow support member 621. The flat head bolt 661 is a shaft-shaped member guided by the groove-shaped rail 665, and has a screw portion 661a screwed to the nut portion 612b of the elbow contact support portion 612 on a lower end side thereof and a head portion 661b on an upper end side thereof. A slide plate 662 is attached to the flush bolt 661 on the upper surface side of the bottom wall 621 a.

A flat head bolt 663 as a second connecting portion is screwed into the nut portion 621e of the elbow support member 621 from below. The flat head bolt 663 is a shaft-like member inserted through the distal end portion of the link member 664, and has a screw portion 663a screwed into the nut portion 621e of the elbow member 621 on the upper end side and a head portion 663b on the lower end side. The link member 664 has a base end portion supported by the toggle contact support portion 612 via a shaft 667, and a base end portion thereof is housed in a recessed portion 612a in the toggle contact support portion 612. A shaft insertion hole 664a is formed in a distal end portion of the link member 664, and a flat head bolt 663 as a second coupling portion penetrates through the shaft insertion hole 664 a.

A tack bolt 663 as a second connecting portion is disposed at the middle in the front-rear direction of the elbow member 621, and the rail 665 is disposed outside the tack bolt 663. The flat-headed bolt 661 as the first connecting portion is engaged with the rear end of the rail 665 when the toggle contact 62 is located at the most advanced position (f), and is moved to the most advanced position (r) so as not to be engaged with the front end of the rail 665. In this way, the link member 664 rotates from the forward position (x) to the backward position (z) via the inward position (y) in which the tip is directed inward, while the toggle contact 62 moves from the most advanced position (f) to the most retracted position (r). Therefore, the toggle contact 62 can be guided by the toggle contact guide mechanism 66 so as to advance and retreat between the most advanced position (f) and the most retreated position (r) through the intermediate position (c), and the toggle contact 62 can be rotated in the vicinity of the intermediate position (c) in conjunction with the advancing and retreating operation.

Next, the operation of the seat forward tilting unit G including the seat forward tilting adjustment unit U in the present embodiment will be described mainly with reference to fig. 6, 7, 9 to 16, and the like.

As shown in fig. 12, in a state where the seat 3 is located at the standard position (a), the front shaft F disposed in the vertically extending elongated hole N of the base B is located below the elongated hole N. The biasing element E, which has one end supported by the front axle F and the other end engaged with the base B, biases the base B obliquely upward with the front axle F as a foothold. The operating lever L23 constituting the drive mechanism L2 is movable between a front position (a) and a rear position (b), and is located at substantially the rear position (b) shown in fig. 15 in a state where the seat 3 is located at the standard position (a).

As shown in fig. 12, the upward movement of the front shaft F is restricted by a lock member L1 that protrudes to a lock position (v) in the elongated hole N. Therefore, even when the seat 3 receives a load due to the sitting person sitting on the seat 3, the front shaft F maintains a state of abutting against the lower surface of the lock member L1.

Next, the seat 3 is moved to the forward tilt position (B). First, the first link member L21 and the second link member L22 are interlocked by rotating the operating lever L23 located at the rear position (b) constituting the lock mechanism L forward. The locking member L1 is connected to the first link member L21 and the second link member L22 via a connecting pin p1, respectively. The lock members L1 are disposed on the base B in a pair on the left and right, and these lock members L1 move forward in conjunction with the forward operation of the operating lever L23. When the operating lever L23 is operated to the front position (a) shown in fig. 16, as shown in fig. 13, the lock member L1 is not present in the elongated hole N, and the front shaft F is in a state of being relatively movable with respect to the seat 3. In this state, the urging element E also urges the base B obliquely upward with the front axis F as a foot-supporting point.

Then, a load is applied downward to the seat 3, and the seat 3 is pushed down to the forward tilting position (B) against the urging of the urging element E. Normally, a load of a seated person seated on the seat 3 applies a downward load to the seat 3. The seat 3 receiving the load rotates with the rear shaft 235 as a rotation center. As the seat 3 rotates, i.e., tilts forward, the base B supported by the seat 3 also moves downward, and the front shaft F supported by the support base 2 moves upward in the elongated hole N relative to the base B in response to the base B sinking. As shown in fig. 14, the upward movement of the front shaft F is prevented by the upper end of the elongated hole N, and the front shaft F is positioned above the elongated hole N.

Then, the seat 3 is locked in the forward tilted position (B). Specifically, in a state where the seat 3 is kept in the forward tilted state against the biasing force of the biasing element E by the load of the seated person or the like, the operating lever L23 located at the forward position (a) is operated to be rotated rearward, and the lock member L1 is moved to the lock position (v) via the first link member L21 and the second link member L22. In a state where the front shaft F is disposed above the lock member L1 located at the lock position (v), even if the load on the seat 3 such as a seated person is removed, the front shaft F is held in a state where the upper surface of the lock member L1 is pressed downward by the urging element E, and the relative movement between the base B and the front shaft F is restricted.

Through the above process, the seat 3 can be moved from the standard position (a) to the forward inclined position (B). That is, according to the seat forward-tilting unit G in this embodiment, the height position of the front portion of the seat 3 from the ground can be selectively switched to a predetermined height position set in advance, specifically, can be selectively switched between 2 stages of the standard position (a) and the forward-tilting position (B).

The chair C in this embodiment includes a seat forward tilting adjustment unit U that is assembled to the base B and can be handled integrally, and a plurality of components for tilting the seat 3 forward relative to the support base 2. Therefore, for example, by selecting whether or not to assemble the seat forward tilting adjustment unit U at the time of manufacture, it is possible to select whether or not to provide the function for forward tilting the seat 3 to the chair C.

The seat forward tilting adjustment unit U in this embodiment includes: a base B serving as a common support structure for constituting an integrated unit; two lock members L1 supported on the base B and capable of moving forward and backward; and a drive mechanism L2 supported by the base B for moving the lock member L1 from the lock position (v) to the unlock position (w).

An example of the manner of attaching the seat forward tilting adjustment unit U will be described below.

First, the base B supporting the lock member L1 and the drive mechanism L2 is disposed between the left and right side walls 211 of the support base 2 having the long holes 212 extending in the front-rear direction.

Next, the front shaft F is passed through the long hole 212 of the support base 2 and through the long hole N of the pedestal B. Thus, the support base 2 and the base B are coupled via the front shaft F in a state of being relatively movable in the vertical direction and the horizontal direction.

Next, the base B is directly mounted to the housing 31 of the seat 3 by the bolt v 4. The housing 31 is provided with a mounting window 311 for mounting the base B. The mounting window 311 has a shape into which the top wall B11 of the base B can be fitted, and the top wall B11 of the base B and its surrounding portion are exposed to the housing 31 in a state in which the base B is mounted to the housing 31.

Then, the urging element E is interposed between the front shaft F installed penetrating the base B and the base B. Specifically, a first spring holder E1 constituting the urging element E is mounted in advance in the middle portion in the left-right direction of the front shaft F, a second spring holder E2 is engageable with the upper end rear portion of the front wall B12 of the base B, and the second spring holder E2 is provided between the upper end rear portion and the first spring holder E1 via a compression coil spring E3. That is, the upper end portion of the second spring holder E2 is engaged with the biasing element engaging portion B121 of the front wall B12 of the base B, whereby the biasing element E is interposed between the front shaft F and the base B. Further, an opening B111 for allowing the operation of engaging the biasing element E with the base B is formed in the ceiling wall B11 of the base B.

Through the above process, the work of mounting the seat forward-tilting adjustment unit U between the housing 31 and the support base 2 is completed.

As described above, in the chair C according to the present embodiment, the seat 3 is supported by the support base 2 via the front shaft F as the coupling member, and the seat forward inclination adjusting means U for adjusting the forward inclination degree, which is the inclination degree of the seat 3 with respect to the support base 2, is interposed between the support base 2 and the seat 3. The seat forward tilting adjustment unit U is assembled to the base B so as to be integrally handled, and the base B is attached to the seat 3, supported by the support base 2, and the distance between the base B and the seat 3 can be changed. Therefore, in the chair in which the seat 3 is tiltable with respect to the support base 2, the seat forward tilting adjustment unit U is provided which is assembled to the base B and can be handled integrally, so that management of parts related to forward tilting of the seat 3 and/or handling at the time of assembly are facilitated.

The seat forward tilting adjustment unit U includes: the base B directly attached to the seat 3; a lock member L1 held by the base B and movable between a lock position (v) for restricting the movement of the base B with respect to the support base 2 and an unlock position (w) for allowing the movement of the base B with respect to the support base 2; and a driving mechanism L2 held by the base B and configured to operate the lock member L1 between the lock position (v) and the unlock position (w) in response to an operation applied from the outside. Therefore, the seat forward tilting adjustment unit U is unitized by supporting the lock member L1 and the drive mechanism L2 on the base B directly attached to the seat 3, and is convenient to handle.

The front shaft F as the coupling member is a shaft-like member held by the support base 2, and the seat forward tilting adjustment unit U includes: a base N provided with a long hole N as a guide portion, the long hole N having a space for guiding the front shaft F to be movable up and down; a lock member L1 held by the base B and movable between a lock position (v) protruding into the elongated hole N to restrict the movement of the front shaft F and a lock release position retracted from the space to allow the vertical movement of the front shaft F; and a driving mechanism L2 held by the base B and configured to operate the lock member L1 between the lock position (v) and the unlock position (w) in response to an operation applied from the outside. Therefore, the seat forward tilting adjustment unit U is engaged with the front shaft F held by the support base 2, whereby the seat 3 can be tilted forward with respect to the support base 2.

The drive mechanism L2 includes: a first link member L21 and a second link member L22 as link members which are interlocked with the locking member L1; and an operating lever L23 for applying an operating force to the first link member L21 and the second link member L22. Therefore, a configuration capable of being compactly supported with respect to the base B is easily achieved.

The forward tilting adjustment unit U includes a pair of lock members L1 engaged with each of the left and right sides of the front axle F, and the lock members L1 are interlocked by an operating force applied to the single operating lever L23 by the drive mechanism L2. Therefore, by operating the operating lever L23, the two lock members L1 can be interlocked, and the relative movement of the front shaft F with respect to the base B can be more reliably restricted.

The present invention is not limited to the embodiments described in detail above.

The seat tilt movement adjusting unit is not limited to a unit that tilts the seat forward with respect to the support base, and may be a unit that tilts the seat backward with respect to the support base.

In the above embodiment, the case where the base of the seat reclining movement adjustment unit is attached to the seat has been described, but the present invention is not limited to this case. That is, the base of the seat reclining adjustment unit may be attached to the support base, and the coupling member may be supported by the seat so that the distance between the coupling member and the support base can be changed.

In the above embodiment, the coupling member is a front shaft, but it is needless to say that the coupling member does not have to be a shaft.

In the above embodiment, the seat forward tilting adjustment unit is attached to the housing of the seat and is configured to be capable of tilting movement integrally with the seat, but the seat forward tilting adjustment unit is not limited to such a configuration. That is, the seat forward tilting adjustment unit may be directly or indirectly attached to the support base. That is, the seat forward tilting adjustment means may be configured to include: a base mounted to the support base; a lock member that is held by a base and is movable between a lock position for restricting movement of the base with respect to the seat and a lock release position for allowing movement of the base with respect to the seat; and a drive mechanism which is held by the base and moves the lock member from the lock position to the unlock position in response to an operation applied from the outside.

Of course, the shape of the base constituting the seat reclining movement adjusting unit, and/or the shape of the locking member, and/or the structure of the driving mechanism may be other shapes and/or structures than those of the above embodiments, and various shapes and/or structures may be applied.

In the above embodiment, the chair is a chair in which the coupling position of the seat and the coupling member is changed, but the chair is not limited to such a chair. That is, the chair may be configured such that the height of the front portion of the seat from the ground is changed by changing the coupling position of the support base and the coupling member, and the seat is integrally tilted forward. For example, the height of the front portion of the seat from the ground surface may be changed by providing the support base with a long hole or the like as a vertical guide portion of the coupling member, and changing the coupling position between the support base and the coupling member, thereby tilting the seat integrally forward.

In the above embodiment, there is shown: the state in which the front axle is held at the specific position and the state in which the front axle is relatively movable with respect to the seat can be achieved by changing the positional relationship between the base and the lock member, which are a plurality of parts engaged with the front axle as the coupling member, but the plurality of parts are not limited to the base and the lock member, and the plurality of parts may be configured by 2 or more kinds of parts.

The specific configuration of each part is not limited to the above embodiment, and various modifications may be made without departing from the scope of the present invention.

Claims (3)

1. A chair in which a seat is supported on a support base via a connecting member, wherein:

interposing a seat tilt movement adjusting unit for adjusting a degree of tilt of the seat with respect to the support base between the support base and the seat;

the seat tilt movement adjusting unit is assembled to the base and can be integrally handled with the base;

the base is attached to one of the seat and the support base, and supports the coupling member on the other side such that a distance between the coupling member and the seat or the support base can be changed,

the coupling member is a shaft-like member held by the support base;

the seat tilt movement adjustment unit includes: a base which is directly or indirectly attached to the seat and is provided with a guide portion having a space for guiding the coupling member to be movable up and down; a lock member held by the base and movable between a lock position where the lock member protrudes into the space to restrict movement of the coupling member and a lock release position where the lock member is retracted from the space to allow an up-and-down movement of the coupling member; and a drive mechanism which is held by the base and moves the lock member between the lock position and the unlock position in response to an operation applied from the outside.

2. The chair of claim 1, wherein:

the drive mechanism includes: a link member linked with the locking part; and an operation lever for applying an operation force to the link member.

3. The chair of claim 1, wherein:

the seat reclining movement adjusting unit includes a pair of the locking members engaged with both left and right sides of the connecting member, respectively, and the driving mechanism causes the two locking members to be interlocked by an operation force applied to a single operation lever.

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