JP6307042B2 - Chair - Google Patents

Description

  The present invention relates to a chair capable of tilting a seat forward.

  In recent years, in offices and the like, there are many operations for operating a keyboard and a mouse toward a display. During such work, if the user sits on the chair for a relatively long time in the office posture, the thigh is easily pressed against the seat. Therefore, in order to be able to correspond to the office posture, a bending point is provided at the center in the front-rear direction of the seat, and the front region of the seat is bent downward with respect to the rear region around this bending point. (For example, refer to Patent Document 1 below).

  However, in such a case, the seated person cannot disperse the seating load in the same manner in the standard posture in which the seat is substantially horizontal and the forward tilted posture in which the front region of the seat is bent downward. Therefore, when switching between these standard postures and forward leaning postures, the user may feel uncomfortable sitting comfort.

  In order to suppress this uncomfortable feeling, the present inventors have focused on rotating the seat between a standard posture in which the entire seat is substantially horizontal and a forward tilting posture in which the entire seat is tilted forward.

  By the way, as a chair in which the seat rotates between a standard posture in which the entire seat is substantially horizontal and a forward tilted posture in which the entire seat is tilted forward, the seated person can operate smoothly between the standing posture and the sitting posture. Various devices having a role of assisting are known (for example, see Patent Document 2 below).

  However, such a chair is configured to rotate around an axis provided at the front end portion of the seat, and when the seat is tilted forward, the rear end side rises upward with respect to the front end side of the seat. become. Therefore, depending on how the backrest is attached, the positional relationship of the backrest with respect to the portion corresponding to the buttocks of the seating surface of the seat may change, and it may be necessary to sit back with the waist lifted. For example, if the seat is deeply seated on the seating surface so that the back is attached to the back, turning the seat from the standard posture to the forward tilting posture around the front end will correspond to the seated person's buttocks on the seating surface of the seat The relative distance (particularly the distance in the vertical direction) between the portion to be seated and the portion corresponding to the waist of the seated person on the backrest seating surface is reduced. Therefore, the upper body of the seated person positioned above the buttocks of the seated person may feel uncomfortable due to such a change in distance. Moreover, the relative height relationship with a desk, a table, etc. used with a chair may change, and it may be necessary to readjust the seat height again. In the same manner as described above, for example, when the seat is deeply seated on the seating surface so that the back is attached to the backrest, if the seat is rotated from the standard posture to the forward leaning posture around the front end, The relative distance (particularly the distance in the vertical direction) between the portion corresponding to the seated person's buttocks on the seating surface and the upper surface of the desk, table, or the like is reduced. Therefore, the upper body of the seated person positioned above the buttocks of the seated person, specifically, the position of the seated person's line of sight and the arm with respect to the upper surface may change, and such a change in distance may cause a sense of incongruity.

  As described above, the conventional chair has a problem that the seating comfort is deteriorated when the seat is switched between the standard posture and the forward tilt posture.

JP 2011-240204 A JP 2011-255075 A

  An object of this invention is to provide the chair which can eliminate or suppress the sense of incongruity which arises when the seat is switched between the standard posture and the forward tilt posture.

The present invention employs the following configuration in order to solve the above-described problems. That is, the chair according to the present invention has a support base provided on the leg, a seat disposed on the support base, and a front end portion to a rear end portion of the seat integrally with the rear portion as a center. And a seat tilting means for tilting from a standard posture to a forward tilting posture , wherein the seat includes an outer shell and an inner shell provided on the outer shell. The outer shell includes an inclined portion that gradually rises forward .

The outer shell has a load receiving surface that receives a load from a seated person, and the load receiving surface is formed with a seating reference point as a center, and the front side of the seating reference point, The inclined portion is provided.

It said inner shell, shall have a load transfer portion for supporting the load from the seated person on the load bearing surface at a site corresponding to the load bearing surface is preferred.

Said load transfer portion, when receiving the load from the seated person, is elastically deformed downward, it shall be configured so as to abut on the load bearing surface is preferred.

It is preferable that a space is formed between the lower surface of the load transmitting portion and the load receiving surface .

It is preferable that the inner shell is disposed on the outer shell so as to be slidable in the front-rear direction within a predetermined range .

  Here, the “sitting position reference point” refers to a point set by design as the center of the seated person's load.

Since the present invention is configured as described above, it is possible to eliminate or suppress the uncomfortable feeling that occurs when the seat is switched between the standard posture and the forward tilt posture.

The perspective view seen from the front side of the chair concerning one embodiment of the present invention. The right view of the chair which concerns on the same embodiment. The rear view of the chair which concerns on the embodiment. The top view of the chair which concerns on the same embodiment. The disassembled perspective view which abbreviate | omitted the tension member of the chair concerning the embodiment. The disassembled perspective view which shows the principal part of the chair which concerns on the same embodiment. The disassembled perspective view which shows the principal part of the chair which concerns on the same embodiment. AA line sectional view of Drawing 4. BB sectional drawing of FIG. Action explanatory drawing shown in the BB sectional view of FIG. Action | operation explanatory drawing which shows the slide guide mechanism of the embodiment typically. Action | operation explanatory drawing which shows the slide guide mechanism of the embodiment typically. The disassembled perspective view which shows the principal part of the chair which concerns on the same embodiment. The front view which decomposes | disassembles and shows the principal part of the chair which concerns on the same embodiment. The rear view which expands and shows the principal part of the chair which concerns on the same embodiment. The CC sectional view taken on the line of FIG. The DD sectional view taken on the line of FIG. EE sectional view taken on the line of FIG. F arrow line view of FIG. The GG sectional view taken on the line of FIG. The disassembled perspective view which shows the principal part of the chair which concerns on the same embodiment. HH sectional view taken on the line of FIG. Action explanatory drawing shown in the HH sectional view of FIG. The perspective view which abbreviate | omits and shows the principal part of the lumbar support apparatus which concerns on the same embodiment. The front view which abbreviate | omits and shows the principal part of the lumbar support apparatus which concerns on the same embodiment. The right view which shows the principal part of the armrest which concerns on the same embodiment. The rear view which shows the principal part of the armrest which concerns on the same embodiment. The schematic diagram which shows the seat forward inclination means and synchro-rocking mechanism which concern on the embodiment. Operation | movement explanatory drawing which shows typically the seat forward tilting means and synchro-rocking mechanism which concern on the embodiment. Operation | movement explanatory drawing which shows typically the seat forward tilting means and synchro-rocking mechanism which concern on the embodiment.

  Hereinafter, an embodiment in which the present invention is applied to a synchro tilt type office rotary chair C will be described with reference to the drawings.

  As shown in FIGS. 1 to 4, the chair C is obtained by mounting an armrest 7 on a chair body C <b> 1.

  The chair body C1 includes a leg 1, a support base 2 supported on an upper portion of the leg 1 and capable of horizontal turning, a seat 4 supported on the support base 2 via a seat frame 3, and the support base. 2 is provided with a backrest 6 supported through a back frame 5 so as to be able to tilt backward.

<Legs>
As shown in FIGS. 1 to 5, the leg body 1 includes a leg blade type leg base 11 having casters 13, and a leg column 12 erected at the center of the leg base 11. . The leg strut 12 is a normal one mainly composed of a gas spring, and the support base 2 is attached to the upper end of the leg strut 12.

<Support base>
As shown in FIGS. 2, 5, 6, 8 to 10 and 13, the support base 2 is supported by the legs 1 so as to be horizontally turnable and vertically movable. A housing 21 mounted on the leg column 12, a backrest supporting main shaft 22 penetrating through both side walls 211 of the housing 21, and a first rotating end 231 provided to be rotatable around the main shaft 22. The bracket 23 having the reaction force receiving shaft 232 and the mounting portion 235 for attaching the back frame to the second rotating end 233, and the reaction force receiving shaft 232 of the bracket 23 to urge the backrest. 6 and a tilt reaction force generation mechanism 24 that generates an elastic reaction force with respect to the backward tilt operation.

  A long hole 212 is formed in the front end portion of both side walls 211 of the housing 21 to support a front connecting member 47 described later so as to be slidable in the front-rear direction.

  The bracket 23 includes a pair of plate-like bracket bodies 234 provided on both sides of the housing 21 and the reaction force receiving shaft 232 connecting the first rotating ends 231 of the left and right bracket bodies 234. And the mounting portion 235 provided to extend outward from the second rotation end 233 of each bracket main body 234. A screw hole 236 is formed in the mounting portion 235, and a back support rod 51 of the back frame 5 described later is fixed to the bracket 23 by a bolt (not shown) screwed into the screw hole 236.

  The tilt reaction force generation mechanism 24 is configured to apply an elastic repulsion force to the reaction force receiving shaft 232 using a coil spring 241, but is not described in detail because it is a normal one. To do.

<Seat frame>
As shown in FIGS. 2 and 5 to 14, the seat frame 3 includes a seat frame main body 31 that holds a rear connection member 46, which will be described later, at the rear end portion 33 and supports the entire seat 4, and A seat front tilt guide 32 is provided at the front end portion 34 of the main body 31 and holds a front connecting member 47 described later so as to be movable up and down.

  The seat frame body 31 is integrally formed of a synthetic resin and has a frame shape having left and right side frame portions 35. The rear end portion 33 of the side frame portion 35 of the seat frame main body 31 includes a bearing portion 351 that holds the rear connecting member 46. The front end portion 34 of the side frame portion 35 of the seat frame main body 31 includes an attachment portion 352 for attaching the seat front tilt guide 32. A gas spring mounting portion 353 is provided inside the intermediate portion of the both side frame portions 35.

The seat forward tilting guide 32 includes a guide main body 36 disposed between the side frame portions 35 of the seat frame main body 31, and an attachment piece 37 for fixing the guide main body 36 to the attachment portion 352 of the side frame portion 35. And is integrally formed of a sheet metal material. The guide main body 36 is inserted between the side frame portions 35 of the seat frame main body 31, and has a ceiling wall 361 positioned above the side frame portion 35 of the seat frame main body 31, and the ceiling wall 361. And side walls 363 that hang downward from both side edges. An arm receiving portion 362 is formed at the front edge of the top wall 361 so as to bend downward. The side walls 363 are formed with guide holes 364 that hold the front connecting member 47 so as to be movable in the vertical direction. The attachment piece 37 is a plate-like one extending outward from the both side walls 363, and the attachment piece 37 is attached to the lower surface of the seat frame body 31 with a screw (not shown). In the present embodiment, the seat front tilt guide 32 is exposed from an opening provided in the outer shell 41 described later, and is directly pressed by the seat body 42, specifically, the lower surface of the inner shell 421. Yes.

<Za>
As shown in FIGS. 1, 2, 4, 5, and 7 to 12, the seat 4 is provided with an outer shell 41 attached on the seat frame 3 and the outer shell 41. A seat main body 42 having an inner shell 421 is provided. Between the outer shell 41 and the inner shell 421, a slide guide mechanism 43 for sliding the inner shell 421 back and forth with respect to the outer shell 41, and the inner shell 421 moved to a desired sliding position. A slide positioning mechanism 44 is provided for locking. In other words, the seat 4 has an outer shell 41 supported by the seat frame 3, a seat body 42 provided on the outer shell 41, and a depth for changing the seating depth dimension of the seat body 42. The depth changing means is provided so that the seat main body 42 can be slid in the front-rear direction on the outer shell 41 by the slide guide mechanism 43, and the seat main body 42 is provided with the slide positioning mechanism 44. Thus, it can be moved and locked to a desired slide position.

  The outer shell 41 has a load receiving surface 411 for receiving a load from a seated person on the upper surface side. The load receiving surface 411 is formed around a sitting reference point T set in the second half region, and includes an inclined portion 412 that gradually rises forward from the sitting reference point T to the front side. . By providing the inclined portion 412, the forward displacement of the seated person can be suppressed, and the fit at the time of sitting can be improved. The load receiving surface 411 is formed around a sitting reference point T that is set as a center of load for the seated person. In the case of a single leg as in the present embodiment, Since a seat occupant's load is applied in the axial direction, the seating reference point T is directly above the support column 12, and the inclined portion 412 is disposed in front of the seating reference point T.

  The operation grip S1 provided below the outer shell 41 is for reaction force adjustment, and adjusts the spring preload of the tilt reaction force generation mechanism 24 provided in the support base 2. ing. On the lower surface of the outer shell 41, a height adjusting lever S2 for adjusting the height position of the seat 4, a tilt locking lever S3 for locking the backrest 6 at a desired locking position, A push button S4 for locking the slide position for operating the slide guide mechanism 43 is provided. Further, a forward tilting lever S5 for operating a seat forward tilting means 45, which will be described later, is provided at the front edge corner of the outer shell 41.

  The forward tilting lever S5 is provided integrally with the shell constituting the seat 4, and specifically, on the outer peripheral edge of the outer shell 41 of the seat 4 so as to follow the outer peripheral edge. Is attached. More specifically, the side edge front end portion of the outer shell 41 of the seat 4 is partially cut away, and the lever S5 is arranged so as to be fitted into the cutout portion. Therefore, the seated person can easily reach the lever S5 while sliding his / her hand along the side edge of the outer shell 41.

  The seat body 42 includes an inner shell 421 disposed on the outer shell 41 through a slide guide mechanism 43 so as to be slidable in the front-rear direction, a cushion 422 disposed on the inner shell 421, and the cushion. 422 and a seat skin material 423 that surrounds the lower surface of the peripheral edge 425 of the inner shell 421.

  The inner shell 421 includes a load transmitting portion 424 for supporting a load from a seated person on the load receiving surface 411 at a portion corresponding to the load receiving surface 411. The inner shell 421 has a shell shape including a step portion 426 whose peripheral edge portion 425 becomes higher in the vicinity of the peripheral edge, and is integrally formed of a synthetic resin that can be elastically deformed. The region surrounded by the step portion 426 includes a front half shell portion 427 that can be slidably in contact with the front half region of the outer shell 41 and a rear end shell that can be slidably in close contact with the rear half region of the outer shell 41. The main part is composed of a part 428 and an intermediate shell part 429 that smoothly leads the front edge of the rear end shell part 428 to the rear edge of the front half shell part 427. The intermediate shell portion 429 is provided with the load transmission portion 424.

  The load transmitting portion 424 is formed by forming a plurality of slits 420 extending in the front-rear direction in the intermediate shell portion 429 with a space in the left-right direction. In a no-load state, a space P <b> 1 is formed between the lower surface of the load transmission portion 424 and the load receiving surface 411. The load transmitting portion 424 can be elastically deformed relatively easily in the thickness direction due to the presence of the slit 420. That is, the load transmitting portion 424 is configured to elastically deform downward and contact the load receiving surface 411 of the outer shell 41 when receiving a load from a seated person. In other words, the load from the seated person is finally received by the load receiving surface 411 of the outer shell 41 via the load transmitting portion 424.

  The inner shell 421 is arranged on the outer shell 41 via the slide guide mechanism 43 so as to be slidable in the front-rear direction within a predetermined range. At this time, the seating depth dimension of the seat 4 can be changed without accompanying the interlocking shift of the load receiving surface 411. That is, as schematically shown in FIGS. 11 and 12, the seating depth dimension of the seat 4 can be changed by sliding the inner shell 421 with respect to the outer shell 41. Since 411 is provided in the outer shell 41, it does not move in conjunction with the sliding movement of the inner shell 421. That is, the range in which the inner shell 421 of the seat 4 can be deflected changes depending on the front / rear slide position. As shown in FIG. 11, a seated person with a relatively small physique often places the inner shell 421 at the rear slide position, and the space P1 is formed to be relatively large in a no-load state. Even if it is light, the inner shell 421 bends, and the effect that cushioning properties can be easily obtained is obtained. On the other hand, as shown in FIG. 12, a seated person having a relatively large physique often places the inner shell 421 at the front slide position, and the space P1 is formed to be relatively small in a no-load state. Even if it is heavy, the effect of being firmly received by the outer shell 41 is obtained.

  The slide guide mechanism 43 is formed at a plurality of locations on the inner shell 421 and extends in the front-rear direction. The slide guide mechanism 43 is slidably inserted in the guide slits 431 and slidably contacts the upper surface of the inner shell 421 at the upper end. A plurality of sliders 432 having retaining heads 433 and a plurality of slider mounting portions 435 provided on the outer shell 41 to fix the lower ends 434 of the sliders 432 are provided. Each of the sliders 432 has a prismatic shape that can slide along the corresponding guide slit 431, and a lower end thereof is attached to the outer shell 41 with a screw (not shown).

  The inner shell 421 that is guided by the slide guide mechanism 43 having the above configuration and slides in the front-rear direction can be positioned and locked at a desired slide position by the slide positioning mechanism 44.

The slide positioning mechanism 44 includes an operation member 441 that can be moved up and down from a lower lock position to an upper lock release position, and a plurality of positioning units that selectively correspond to the operation member 441 as the inner shell 421 slides. And an engaging portion 443 for use. In the slide positioning mechanism 44, the inner shell 421 is prohibited from sliding while the operation member 441 is lowered to the lower lock position and engaged with the corresponding engagement portion 443, and the operation member 441 is moved to the upper position. The engagement with the engagement portion 443 is released in the state where the lock is raised to the unlocked position, and the sliding movement of the inner shell 421 is allowed. The operation end of the operation member 441 protrudes from the lower surface side of the outer shell 41. By operating the push button S4 of the operation member 441 upward, the main part of the seat 4 including the operation member 441 can be moved with respect to the outer shell 41, and the seating depth dimension of the seat 4 can be changed. It has become.

  The cushion 422 is formed by pasting a nonwoven fabric on the lower surface of molded urethane, for example. More specifically, the cushion 422 is mounted on the upper surface of the inner shell 421 and is wrapped by the seat skin 423 made of cloth or the like together with the peripheral edge 425 of the inner shell 421. .

  The seat 4 described above is supported by the support base 2 via the seat forward tilting means 45.

<Front tilting means>
As shown in FIGS. 5, 6, 9, and 10, the seat forward tilting means 45 is indicated by a solid line in FIG. 9 with the entire seat 4 disposed on the support base 2 as the center. In addition, it is for tilting from a standard posture (A) indicated by a thick two-dot chain line in FIG. 10 to a forward tilt posture (B) indicated by a solid line in FIG. 28 and 29 schematically show each component of the seat forward tilting means 45. In FIG. 29, the standard posture (A) is indicated by a two-dot chain line, and the forward tilt posture (B) is indicated by a solid line. Is shown. The seat forward tilting means 45 is provided on the seat frame 3 supporting the whole seat 4 and the rear end portion 33 of the seat frame 3, and indirectly pivoted to the support base 2 via the back frame 5. A supported rear connection member 46, a front connection member 47 provided at the front end portion 34 of the seat frame 3 and supported by the front end portion of the support base 2, and a front end portion of the seat frame 3 with respect to the front connection member 47 And a lock mechanism 48 for changing the position 34 in the vertical direction and locking it at a desired position.

  The rear connecting member 46 is a shaft-like member held by a bearing portion 351 provided at the rear end portion 33 of the seat frame 3, and both end portions thereof are pivotally attached to the bearing portion 513 of the back frame 5. . In the present embodiment, the rear connecting member 46 is configured to be positioned in the vicinity of the sitting position reference point T set by design as the center of the seated person's load.

  The front connecting member 47 is a shaft-like member that is held in a long hole 364 provided in the seat front tilt guide 32 of the seat frame 3 so as to be vertically movable, and can be slid back and forth in the long hole 212 of the support base 2. Is inserted.

  The lock mechanism 48 has one end 491 supported by the seat frame 3 and a gas spring 451 that is an urging means capable of changing the position of the other end 454 with respect to the one end 453, and the position of the other end 454 of the gas spring 451. And a motion converting unit 452 that converts the change into a vertical position change of the front end portion 34 of the seat frame 3 with respect to the front connecting member 47.

  The gas spring 451 can be switched between a locked state and a non-lockable state that can be expanded and contracted.

The motion converting portion 452 has a seat front tilt base 49 attached at one end 491 to the support base 2 via the front connecting member 47 so as to be movable back and forth, and an intermediate fulcrum 401 at the other end 492 of the seat front tilt base 49. And a seat front tilt adjustment arm 40 having one rotation end 402 connected to the seat frame 3 and the other rotation end 404 connected to the gas spring 451.

  The seat forward tilt base 49 is provided with a hanging plate 495 on both left and right edges of a flat plate 493 arranged substantially horizontally, and a bearing portion 496 for holding the front connecting member 47 is formed at the front end of the hanging plate 495. Has been. In addition, standing walls 494 that make a pair are erected on the rear edge of the flat plate 493, and the intermediate fulcrum 401 of the seat front tilt adjustment arm 40 is pivotally attached to the standing walls 494. The lower surface of the flat plate 493 of the seat forward tilt base 49 is supported on the support base 2 so as to be slidable back and forth, and the downward swing of the seat forward tilt base 49 is prohibited. When the seat 4 performs a sinking operation in conjunction with the backward tilting operation of the backrest 6 by the action of the synchro-rocking mechanism R described later, the seat forward tilting base 49 and the front connecting member 47 are moved in the front-rear direction. Configured to move to.

  The seat forward tilt adjustment arm 40 has a width dimension that can be disposed between the upright walls 494, and has an L-shape in side view that bends at the position of the intermediate fulcrum 401 pivotally attached to the upright wall 494. ing. A shaft-like protrusion 403 is provided on one rotation end 402 of the seat front tilt adjustment arm 40. The shaft-like projection 403 is pivotally supported by the arm receiving portion 362 of the seat front tilt guide 32 of the seat frame 3 so as to be rotatable and slidable in the front-rear direction. A shaft hole 405 is formed in the other rotation end 404 of the seat front tilt adjustment arm 40. The rotating end 404 is pivotally attached to the other end 492 of the gas spring 451 through a connecting shaft 406 inserted into the shaft hole 405.

  In this embodiment, as described above, all the components of the lock mechanism 48 are assembled into the seat frame 3 to form a unit.

<Back frame>
As shown in FIGS. 2, 3, 5, 9, 10, 13, 13-18, 22 and 23, the back frame 5 has an L-shape in a side view having a rising portion. The left and right dorsal support rods 51 extending horizontally in the front-rear direction, the left and right connecting members 52 attached to the rear ends of the dorsal support rods 51 to form the rising portion, and the left and right dorsal support rods 51 are coupled. And a horizontal member 53. In other words, the back frame 5 that supports the backrest 6 is supported by the support base 2 provided on the leg body 1, and the left and right back support rods 51 extending rearward, and the rear ends of these back support rods 51. The left and right connecting members 52 extending upward are mainly configured, and the connecting members 52 are respectively attached to the upper sides of the left and right back support rods 51, and the lower end portion of the backrest 6 is supported via the connecting members 52. ing.

  Each said back support rod 51 is open | released inside, and is integrally formed by aluminum die-casting. The base end portion of each back support rod 51 has a boss portion 511 fitted to the end portion of the main shaft 22 and is fixed to the attachment portion 235 of the bracket 23 using a bolt (not shown) in the vicinity of the base end portion. An intermediate rib 512 is provided. An intermediate portion of each back support rod 51 includes a bearing portion 513 for pivotally attaching the rear connecting member 46. The tip of each back support rod 51 has a mounting base 514 for screwing the horizontal member 53 and a plate-like connecting member mounting protrusion 515 extending integrally upward. The left and right back support rods 51 can be pivoted to the support base 2 by screwing the intermediate rib 512 to the mounting portion 235 of the bracket 23 with the boss portion 511 fitted to the main shaft 22. It is attached.

The connecting member 52 has a shape that fits between the left and right side edges of the backrest 6 in a front view. Each of the connecting members 52 is interposed between the backrest 6 and the backrest 51, and is separate from the backrest 51 and the backrest 6, respectively. Each connecting member 52 is integrally provided with facing walls 54 and 55 that form a pair each provided with opposing pressing surfaces 541 and 551. That is, each connecting member 52 includes an upper facing wall 54 that supports the lower edge of the backrest 6, a lower facing wall 55 disposed below the upper facing wall 54, both the facing walls 54, A base end side connecting wall 56 that integrally connects the base end sides of 55, and a back side connecting wall 57 that connects the front edge portions excluding the front end portions of the two facing walls 54, 55; It is molded integrally by die casting.

  On the upper surface of the upper facing wall 54, a backrest mounting projection 542 having a nut portion 545 for mounting the backrest 6 is provided. The upper facing wall 54 has an escape hole 544 for preventing interference with a first mounting bolt B4 for mounting an armrest 7 described later provided on the base end side, and an armrest described later provided on the distal end side. And a nut portion 545 for attaching 7.

  The lower facing wall 55 has a bolt insertion hole 552 corresponding to the first mounting bolt B4 and a bolt insertion hole 553 for inserting the second mounting bolt B5 for screwing into the nut portion 545. Is provided. The lower facing wall 55 is formed with an opening 554 into which the connecting member mounting protrusion 515 can be inserted.

  The proximal-side coupling wall 56 is for rigidly coupling the proximal ends of the upper and lower facing walls 54 and 55, and the left and right back support rods are disposed between the inner side surfaces of the left and right proximal-side coupling walls 56. A space P <b> 2 that is continuous with the space P <b> 3 formed between 51 is formed.

  The back side connecting wall 57 is connected to the connecting member mounting protrusion 515 by a bolt (not shown) inserted from the rear in a state where the connecting member mounting protrusion 515 inserted into the opening 554 of the lower facing wall 55 is overlapped. It is fixed to the connecting member 52. That is, the back side coupling wall 57 is provided with a nut portion 571, and a bolt insertion hole 516 is formed in the connecting member mounting projection 515 so as to coincide with the nut portion 571. . The connecting member 52 is fixed to the back support rod 51 by the bolt screwed to the nut portion 571 through the bolt insertion hole 516.

  The upper and lower facing walls 54, 55 of each connecting member 52 have a free end structure on the front end side, and are configured so that the pressing surfaces 541, 551 can be brought close to each other by utilizing elastic deformation of the members. Yes. A mounting region 58 that is opened rearward is formed by the facing walls 54 and 55 having at least the clamping surfaces 541 and 551 and the back side coupling wall 57. In other words, the attachment region 58 extends in the left-right direction along the lower edge of the backrest 6 on the back surface of the chair body C1 provided with the backrest 6, and the armrest 7 as an optional member is attached to the attachment region 58. I try to install it. That is, the attachment region 58 is formed by recessing a specific portion of the chair body C1, and specifically, is provided on the connecting member 52 that is a rising portion of the back frame 5.

  The horizontal member 53 is for connecting the front ends of the back support rods 51, and both ends thereof are fixed to the mounting bases 514 of the back support rods 51 by bolts B6. Between the horizontal member 53 and the support base 2, a gas spring 50 for backward tilt locking is disposed in the space P3. The gas spring 50 has a function of fixing the rearward tilting operation of the back frame 5 at a desired position in the locked state, and in the unlocked state, the gas spring 50 generates the biasing force of the tilting reaction force generating mechanism 24 by its elastic repulsive force. It has a function to assist.

<Backrest>
As shown in FIGS. 1 to 5, 9, 10, and 13 to 27, the backrest 6 includes a frame-like back support member 61 called a so-called back frame, and a back support member 61. It is provided with a mesh-like tension member 62 that is tensioned and receives the load of a seated person, and a lumbar support device 8 that is provided on the back support member 61, and is attached on the connecting member 52 of the back frame 5. Yes.

  The back support member 61 has a gate shape including at least left and right side frames 64 and an upper frame 66 disposed between upper ends of the side frames 64. Specifically, the back support member 61 is integrally formed of synthetic resin, and includes a left and right side frame 64, a lower frame 65 that joins the lower ends of the side frames 64, and an upper end of the side frame 64. And an upper frame 66 for joining the two.

  Each of the side frames 64 includes side frame bodies 641a and 642a that form the side edges of the backrest 6, and a lumbar support member that is assembled in the side frame bodies 641a and 642a and forms a part of the lumbar support device 8. 81a and 82a.

  The side frame bodies 641a and 642a are arranged integrally with a first frame forming a front frame portion having a first back surface 643 and a rear side of the first frame, and are attached to the first back surface 643. And a second frame forming a rear frame portion having an adjacent second back surface 644. The first back surface 643 and the second back surface 644 are flush with each other in the upper portion 646, but are formed so as to be gradually separated in the front-rear direction from the middle toward the bottom. That is, the second back surface 644 is set so as to be gradually located rearward with respect to the first back surface 643, and the entire side frame bodies 641a and 642a gradually increase in thickness in the front-rear direction from the middle. It has a form that increases. In other words, the front frame portion and the rear frame portion are largely separated in the front-rear direction in the protruding portion corresponding to the vicinity of the waist of the seated person with the center portion protruding most forward, and in the front-rear direction arranged in this portion The front frame part and the rear frame part are connected by the extending wall. Therefore, the side frame main bodies 641a and 642a are configured so that the strength of the portion corresponding to the waist of the seated person can be increased and the lumbar support device 8 can be attached to this portion. More specifically, the side frame main bodies 641a and 642a have a waist part 645 that protrudes most forward slightly below the center part and the two back faces 643 and 644 are most separated from each other, and is inclined upward from the waist part 645 while being inclined rearward. And a lumbar device attachment portion for attaching the lumbar support device 8 to the waist portion 645 having the largest longitudinal dimension, and the lumbar device attachment portion of the waist portion 645 has the lumbar device attachment portion. 8 is provided.

  The waist portions 645 of the side frame bodies 641a and 642a include bottom walls 647b and 648b, left and right side walls 647d and 648d, top walls 647e and 648e, and rear walls 647f and 648f, and are opened forward. Further, lumbar mounting spaces 647a and 648a, which are the lumbar device mounting portions, are formed. The left lumbar mounting space 647a of the left side frame body 641a in the front view has a deeper shape than the right lumbar mounting space 648a of the right side frame body 642a in the front view. Further, a rear surface 647g of the rear wall 647f forming the left lumbar mounting space 647a partially protrudes rearward from the first and second rear surfaces 643 and 644. Bolt insertion holes 647c and 648c corresponding to the nut portion 545 of the connecting member 52 are formed in the bottom walls 647b and 648b of the left and right side frame bodies 641a and 642a, and these bolt insertion holes 647c and 648c are viewed from above through the bolt insertion holes 647c and 648c. The back support member 61 is fastened to the connecting member 52 by bolts B <b> 7 and B <b> 8 screwed to the upper half of the nut portion 545. An attachment groove 649 for accommodating the end edge of the tension member 62 is formed in the vicinity of the front edge of the side frame 64.

The lower frame 65 is integrated with a central portion 651 located in the center in the left-right direction, and extends obliquely upward while gradually protruding forward from both ends of the central portion 651 and is continuously integrated with the lower inner surface of the side frame 64. The left and right end portions 652 are integrally provided, and the left and right end portions 652 are attached to the left and right connecting members 52. More specifically, the lower frame 65 has a hollow body shape opened downward, and includes a front structural wall 653, a rear structural wall 656 provided on the rear side of the front structural wall 653, and the rear structural wall. And a decorative wall 658 provided on the rear side of 656.

  The front structural wall 653 includes a plurality of bolt insertion holes 654 having counterbore holes through which the head of the bolt B1 can pass on the front end side. Then, the back support member 61 is fixed to the connecting member 52 by screwing the bolt B1 inserted from the front side into the bolt insertion holes 654 into the nut portion 543 of the backrest mounting projection 542 of the connecting member 52. ing. That is, the back mounting protrusion 542 of the connecting member 52 is inserted between the front structural wall 653 and the rear structural wall 656 of the lower frame 65, and the lower end of the front structural wall 653 on the upper surface of the connecting member 52. The back support member 61 is attached to the connecting member 52 in a state where the lower end of the rear structural wall 656 is in contact. In this attached state, the back surface 59 of the connecting member 52 and the back surface 657 of the rear structure wall 656 of the lower frame 65 are set to be flush with each other. Further, the back surface 657 of the rear structure wall 656 of the lower frame 65 is continuous with the first back surface 643 of the side frame 64, and the back surface 659 of the decorative wall 658 is the second back surface of the side frame 64. It is continuous with 644. An attachment groove 655 for accommodating the end edge of the tension member 62 is formed at the lower end of the front structural wall 653.

  The upper frame 66 connects the upper ends of the left and right side frames 64, and is an edge fixing portion for fixing the edge of the tension member 62 to the edge 667 of the upper edge of the back support member 61. A groove 661 is provided. The upper frame 66 is provided on the front side of the mounting groove 661, a backing curved surface 662 capable of backing up the tension member 62 and smoothly leading to the mounting groove 661, and an optional member provided on the rear side of the mounting groove 661. And a groove 663 for detachably attaching a mounting portion of a certain hanger. The groove 663 is formed along the end edge 667, and the width dimension is gradually changed from the center toward the outer side. Specifically, the groove 663 has a width dimension, which is a separation distance L1 between the inner surface 664 on the front side and the inner surface 665 on the rear side, set to be gradually smaller from the center toward the left and right outer sides. The rear inner side surface 665 is formed to have a V-shape that is flat in a rear view and has a ridge line corresponding portion 666 corresponding to the ridge line formed in the attachment portion of the option member at the center.

  Further, as shown in FIGS. 19 and 20, the backrest 6 includes a visual recognition edge 621 on the seating surface side of the tension member 62 and the edge fixing as viewed from the direction in which the end edge 667 of the back support member 61 extends. The separation distance L2 from the viewing edge 622 on the fixed side fixed to the portion is partially different. Specifically, the separation distance L2 of the tension member 62 fixed to the upper frame 66 is gradually decreased from the center toward the outer side. That is, in this embodiment, an attachment groove 661 that opens in the direction in which the end edge 667 extends is formed in the end edge 667 of the upper frame 66, and the edge of the tension member 62 is inserted into the attachment groove 661. It is fixed. The visible edge on the side fixed to the mounting groove 661 is referred to as the fixed-side visual edge 622. The “direction in which the end edge 667 extends” means a direction in which the center line in the thickness direction of the upper frame 66 extends as shown in FIGS. 2 and 20, and the mounting groove 661 also extends along this direction. Is formed. The visible edge on the side forming the seating surface guided by the backing curved surface 662 is referred to as the viewing edge 621 on the seating surface side.

  The tension member 62 has a mesh shape that receives the load of the seated person. More specifically, the tension member 62 has its left and right edges inserted and fixed in the mounting groove 642 of the side frame 64, its lower edge inserted and fixed in the mounting groove 655 of the lower frame 65, and its upper edge fixed. By being inserted into the mounting groove 661 of the upper frame 66 and being fixed, it is stretched on the back support member 61 having a frame shape.

The lumbar support device 8 includes the left and right side frames 64, a plurality of lines 83 extending between the side frames 64, and a line in another line by an external force applied to the lines 83 in a specific line. Strip 83
And a tension state adjusting mechanism 84 that reversibly changes the tension of the tension. In the present embodiment, the plurality of linear bodies 83 are arranged in parallel to each other, and the “row” is used for convenience to count the linear bodies 83 that are extended in the left-right direction. It is.

  The left side frame 64 in the front view includes the side frame main body 641a, a lumbar support member 81a that is disposed in the left lumbar mounting space 647a of the side frame main body 641a and supports the linear body 83, and the lumbar support member. And a cover 81d covering the front side of 81a. The lumbar support member 81a and the cover 81d are fastened together with a bolt B9 inserted from the front side to the front end of a mounting boss 647h protruding from the rear wall 647f of the side frame body 641a. The main part of the tension state adjusting mechanism 84 is disposed between the lumbar support member 81a and the rear wall 647f. The lumbar support member 81a is provided with a plurality of bending guide portions 81b that guide the rear end while slidably supporting the left end portions 831 of the plurality of lines 83, and these bending guide portions. The front side of 81b is closed by the cover 81d.

  The right side frame 64 in the front view includes the side frame main body 642a, a lumbar support member 82a disposed in the right lumbar mounting space 648a of the side frame main body 642a, and a cover that covers the front side of the lumbar support member 82a. 82d. The lumbar support member 82a and the cover 82d are fastened together with a bolt B10 inserted from the front side to the front end of a mounting boss 648h provided on the rear wall 648f of the side frame body 642a. The lumbar support member 82a includes a plurality of linear guide portions 82b that slidably support the right end portion 834 of the plurality of lines 83, and outer ends of the linear guide portions 82b that are vertically adjacent to each other. And a curved guide portion 82c having a semicircular arc shape that smoothly continues, and the front sides of the linear guide portion 82b and the curved guide portion 82c are closed by the cover 82d.

  The linear body 83 is made of a wire that can be flexibly deformed, and the plurality of rows of linear bodies 83 are made of a single wire material. In other words, except for the left end portion 832 of the top row of line bodies 83 and the left end portion 833 of the bottom row of line bodies 83, each row of line bodies 83 is a lumbar. The mounting spaces 647a and 648a are integrally continuous. In other words, the wire 83 in each row and the connecting wire 835 that connects the ends 831 and 834 of the adjacent wire 83 in the side frame 64 are constituted by one wire material. . In this embodiment, the line 83 in each row is located in the vicinity of the tension member 62 that receives the load of the seated person, and is movable relative to the tension member 62. The linear bodies 83 in each row are arranged in a state of being stretched between the side frames 64, and come into contact with the tension members 62 deformed rearward when seated. Therefore, the outer periphery is individually covered with the covering member 836 for the purpose of preventing the tension member 62 from being damaged.

  The covering member 836 is a tube-like member that is separate from the linear body 83 and covers the entire circumference of the linear body 83. Specifically, the covering member 836 is for exposure prevention that covers a main tube 837 that covers the entire circumference of the linear body 83 and a frame proximity portion of the linear body 83 including both ends of the main tube 837. And a sub tube 838.

The tension state adjusting mechanism 84 is supported by the side frame main body 641a and disposed in the lumbar mounting space 647a, and a center portion in the vertical direction is rotatably supported by the fulcrum member 841. And an adjusting arm 842 capable of performing a balance operation in the front-rear direction in the lumbar mounting space 647a. The fulcrum member 841 and the adjustment arm 842 are disposed between the lumbar support member 81a and the rear wall 647f. The adjustment arm 842 includes an end portion attaching portion 843 for attaching the end portions of the wire 83 provided at both upper and lower end portions, and a plurality of curved guide portions 844 provided in the middle for smoothly guiding the wire material. ing. Each curved guide portion 844 is mainly composed of a semi-arc-shaped guide projection 845 formed on the side surface of the adjustment arm 842, and a wire material is removed from the protruding end of the guide projection 845. A flange 846 is provided integrally to prevent it.

  A plurality of rows of line bodies 83 are arranged in parallel with a space between the left lumbar support member 81a and the right lumbar support member 82a, and the left end of the line bodies 83 of each adjacent row is arranged. The left connecting wire portion 835 that connects the portions 831 is guided rearward by the bending guide portion 81b and is slidably supported by the curved guide portion 844 of the adjusting arm 842, and the adjacent line members A right connecting line portion 835 that connects the right end portions 834 of 83 is slidably supported by the curved guide portion 82c of the right lumbar support member 82a. Further, the left end portion 832 of the uppermost line 83 is guided to the rear by the bending guide portion 81b and is rotatably attached to the upper end mounting portion 843 of the adjustment arm 842. . The left end portion 833 of the lowermost line 83 is guided rearward by the bending guide portion 81b and rotatably attached to the lower end attachment portion 843 of the adjustment arm 842. Yes.

  The lumbar support device 8 also includes a tension adjusting unit 85 for changing the average tension of the line 83 in each row. The tension adjusting unit 85 is for changing the holding position of the fulcrum member 841 in the front-rear direction. The tension adjustment unit 85 is provided with a screw hole 851 in the fulcrum member 841 and a screw rod 852 screwed into the screw hole 851 on the side. An operation grip 853 for rotating the screw rod 852 is provided at the outer penetrating end of the screw rod 852 so as to be rotatably inserted in the rear wall 647f of the frame main body 641a. The front end of the screw rod 852 is rotatably supported by the lumbar support member 81a.

  In such a lumbar support device 8, the adjusting arm 842 is appropriately rotated in the front-rear direction by an external force applied to the linear body 83 in a specific row, and the tension of the linear body 83 in other rows is relatively changed. It is like that. Specifically, for example, when the upper linear member 83 is pushed rearward, the upper end side of the adjustment arm 842 is pulled forward and rotated, that is, the fulcrum member 84 that is the rotation axis of the adjustment arm 842 is a boundary. Thus, the tension of the linear body 83 is changed relative to the upper and lower sides, and the tension of the linear body 83 in another row attached or held to the lower end side of the adjustment arm 842 becomes stronger. Further, when the operation grip 853 is rotated to change the holding position of the fulcrum member 841 in the front-rear direction, the tension of the line bodies 83 in all rows changes. As described above, when the tension of the line 83 in each row changes in a reciprocal manner, each connecting line 835 slides appropriately with respect to the corresponding curved guides 82c and 844. Become.

  The lumbar support device 8 configured as described above includes the left and right lumbar support members 81a and 82a, the adjustment arm 842 disposed on the rear side of the lumbar support members 81a and 82a, the lumbar support members 81a and 82a, and the adjustment. A unit 86 having a linear body 83 spanned over the arm 842 and a tension adjusting portion 85 excluding the operation grip 853 is provided, and the unit 86 is incorporated into the side frame main bodies 641a and 642a from the front side. ing. The threaded rod 852 of the tension adjusting unit 85 includes a threaded rod main body 854 screwed to the fulcrum member 841 and a retaining rod 855 screwed to the rear end of the threaded rod main body 854. When the unit 86 is attached to the side frame main body 641a, the screw rod main body 854 is passed through the rear wall 647f of the side frame main body 641a with the retaining rod 846 removed, and the screw rod main body 854 An operation grip 853 is attached to the outer periphery of the penetrating end, and a retaining rod 855 is screwed to the penetrating end. The lumbar support members 81a and 82a are screwed and fixed to the side frame bodies 641a and 642a together with the covers 81d and 82d while being accommodated in the lumbar mounting spaces 647a and 648a.

  The backrest 6 having the above-described configuration and the seat 4 described above are tilted at a constant ratio by the synchro-rocking mechanism R.

<Synchloro-packing mechanism>
As shown in FIGS. 9 and 10, the synchro-rocking mechanism R supports the front connection member 47 held by the seat frame 3 to the support base 2 so as to be movable back and forth, and is held by the seat frame 3. Further, the rear connecting member 46 is pivotally supported on the back frame 5 so that the backward tilting operation of the backrest 6 and the sinking operation of the seat 4 are interlocked. That is, the synchro-rocking mechanism R is connected to the front end portion 34 of the support base 2 via the front connecting member 47 so that the front end side of the seat frame 3 that supports the seat 4 can be moved back and forth. The rear end side is pivotally supported on the back frame 5 via the rear connecting member 46. Specifically, the front connecting member 47 is slidably supported by a long hole 212 provided in the front end portion of the support base 2 and extending in the front-rear direction. The rear connecting member 46 also serves as a pivot point of the seat forward tilting means 45 described above, and is rotatable on a bearing portion 513 provided on the back support rod 51 of the back frame 5. 28 and 30 schematically show each component of the synchro-rocking mechanism R. In FIG. 30, the standard posture (A) is indicated by a two-dot chain line, and the backrest 6 is tilted backward. The sinking posture (C) in which the rear end side of the seat 4 is sinked is indicated by a solid line.

<Armrest>
As shown in FIGS. 1 to 5, 13 to 18, 22, 23, 26, and 27, the armrest 7 is one of optional members that are detachably attached to the chair body C1. And an elbow frame 71 having a base end portion 73 attached to the attachment region 58 of the connecting member 52 of the chair main body C1 and an armrest main body 72 provided at a distal end portion 75 of the elbow frame 71.

  The elbow frame 71 includes a base end portion 73 that extends along the lower edge of the backrest 6, an intermediate bend portion 74 that is provided continuously with the base end portion 73 and bends forward and upward, and this intermediate bend. It is provided with the front-end | tip part 75 provided continuously from the part 74 and extended in front upper direction. The armrest main body 72 is provided at the upper end of the distal end portion 75.

  The armrest main body 72 includes an elbow rest 721 formed integrally with the elbow frame 71 and an elbow rest 722 attached on the elbow rest 721. The elbow receiver 721 is integrally formed with the elbow frame 71 and a synthetic resin.

  The base end portion 73 of the elbow frame 71 corresponding to the base end portion of the armrest 7 has a shape that fits into the recessed mounting region 58 of the connecting member 52, and mainly from the rear side to the mounting region 58. It is designed to be fitted. That is, the base end portion 73 of the elbow frame 71 includes an upper surface 731 that is in close contact with or very close to the facing wall 54 on the connecting member 52, a lower surface 732 that is in close contact with or very close to the lower facing wall 55, and the base A base end surface 733 that is in close proximity to or very close to the end-side coupling wall 56, a back surface 734 that is flush with the back surface 59 of the connecting member 52, and a front surface 735 that corresponds to the back-side connecting wall 57 of the connecting member 52. It is a thing. The front surface 735 includes an inner region 76 that faces the head of the bolt, an intermediate region 77 that abuts on the inner coupling wall 57, and an outer region that is located outside the outer edge 572 of the inner coupling wall 57. 78. At the boundary between the inner region 76 and the intermediate region 77, an inner stepped portion 79 that engages with the edge of the connecting member mounting protrusion 515 of the back support rod 51 is formed. Further, an outer stepped portion 70 is formed at the boundary between the intermediate region 77 and the outer region 78 so as to engage with the outer edge 572 of the back side coupling wall 57.

The base end portion 73 of the elbow frame 71 is fixed to the connecting member 52 using the first mounting bolt B4 and the second mounting bolt B5. More specifically, the base end portion 73 of the elbow frame 71 has a first bolt insertion hole 736 whose axis is aligned with the bolt insertion hole 552 and the escape hole 544 of the connection member 52, and the connection member 52. The bolt insertion hole 553 and the nut part 545 are provided with a second bolt insertion hole 738 whose axis is aligned. An embedded nut 737 is disposed in the middle of the first bolt insertion hole 736. Then, the base mounting end B5 is inserted into the bolt insertion hole 552 of the connecting member 52 and the first bolt insertion hole 736 of the elbow frame 71 from below, and is screwed into the embedded nut 737 and tightened to tighten the base end. The portion 73 is brought into close contact with and fixed to the facing wall 55 below the connecting member 52. The tip of the first mounting bolt B4 that has passed through the embedded nut 737 is inserted into a relief hole 544 provided in the upper facing wall 54. Also, a nut portion provided on the facing wall 54 above the connecting member 52 includes a second mounting bolt B5 inserted from below into the bolt inserting hole 553 of the connecting member 52 and the second bolt inserting hole 738 of the elbow frame 71. The base end portion 73 is brought into close contact with and fixed to the upper and lower facing walls 54 and 55 of the connecting member 52 by screwing and tightening to the lower half portion of 545. In other words, the base end portion 73 is clamped from above and below by the clamping surface 541 of the upper facing wall 54 and the clamping surface 551 of the lower facing wall 55 by the tightening force of the second mounting bolt B5 as a fastening member. It is fixed. That is, the tip portions of the upper and lower facing walls 54 and 55 that are not supported by the inner side coupling walls 57 form a cantilever support structure. Therefore, the base end portion 73 is firmly fixed to the connecting member 52 by elastically deforming the tip portions of the upper and lower facing walls 54 and 55 with the second mounting bolt B5 and bringing the pressing surfaces 541 and 551 closer to each other. Has been.

  When the armrest 7 is not attached to the chair body C1, a cover 7a that is one of optional members is attached instead of the armrest 7. As shown in FIGS. 26 and 27, the cover 7 a is attached to the attachment region 58 in the connecting member 52 of the chair body C <b> 1 and extends along the lower edge of the backrest 6. That is, the cover 7a has the same shape as the base end portion 73 of the armrest 7 described above, and has a shape that fits into the recessed mounting region 58 of the connecting member 52. The cover 7a is attached to the chair body C1. In the mounted state, the top edge of the upper and lower facing walls 54 and 55 of the connecting member 52 and the outer edge of the cover 7a are configured to coincide with each other.

  As described above, the chair C according to the present embodiment includes the support base 2 provided on the leg 1, the seat 4 disposed on the support base 2, and the entire seat 4, that is, the seat 4. And a seat forward tilting means 45 that tilts from the standard posture (A) to the forward tilt posture (B) from the front end to the rear end integrally. Therefore, since the seat 4 as a whole is tilted, the seated person is the same in the standard posture (A) and the forward leaning posture (B) as compared with the conventional case in which only the front region of the seat is bent downward. The seating load can be dispersed. In addition, since it tilts forward about the rear part of the seat 4, compared to the conventional one that pivots around the shaft provided at the front end of the seat, the seat 4 has a lower part on the seating surface. The positional relationship of the seating surface of the backrest 6 with respect to the corresponding portion, particularly the vertical distance of these changes, or the positional relationship of the portion corresponding to the buttocks of the seating surface of the seat 4 with respect to the upper surface of the desk, table, etc. It is possible to eliminate or suppress the occurrence of a problem in which the vertical separation distance changes. Therefore, when the seat 4 is switched between the standard posture (A) and the forward tilted posture (B), it is possible to save time and effort to re-sit with the hips 4 and to adjust the height of the seat 4 again. . Thus, according to this embodiment, even when the seat 4 is adjusted by itself while in the sitting state and the seat 4 is switched between the standard posture (A) and the forward tilt posture (B), the sitting comfort is good. It can be.

  In addition, since the seat 4 can be tilted to the forward tilted posture (B), when performing a personal computer driving operation or the like, the seat 4 is tilted at an angle at which it does not get tired even if it is seated in the chair C for a relatively long time in the office posture. It is possible to adjust.

In particular, the chair C of the present embodiment is such that the backrest 6 is supported by the support base 2 so as to be able to tilt backward, and the seat 4 is supported by the support base 2. The front connecting member 47 provided on the back base 6 is supported by the support base 2 so as to be movable back and forth, and the rear connecting member 46 provided on the rear end of the seat 4 is pivotally supported by the backrest 6 so that the backrest is supported. 6 is a chair C in which the backward tilting motion of the seat 6 and the sinking motion of the seat 4 are interlocked. The seat forward tilting means 45 tilts forward from the standard posture (A) with the rear coupling member 46 as the center. Tilt up to the posture (B). That is, the rear connecting member 46, which is a shaft for connecting the backrest 6 and the seat 4 in the synchro-rocking mechanism R, is also used as the rotation shaft of the rear portion of the seat 4. As described above, since the rotation axis of the seat tilting means 45 and the axis of the synchro-rocking mechanism R are shared, a simple structure can be achieved.

  The seat forward tilting means 45 is provided on the seat frame 3 that supports the entire seat 4 and the rear end portion 33 of the seat frame 3 and is pivotally supported by the support base 2. In other words, A rear connection member 46 pivotally supported by the support base 2 via the back frame 5, a front connection member 47 provided at the front end 34 of the seat frame 3 and supported by the front end of the support base 2, Since the lock mechanism 48 that changes the position of the front end portion 34 of the seat frame 3 with respect to the connecting member 47 in the vertical direction and locks it at a desired position is provided, a desired inclined state can be maintained. Further, it is not necessary to provide a shaft for exclusive use of the forward tilt as compared with the conventional case where only the front region of the seat bends downward, and the seat 4 using the connecting point of the seat frame 3 and the back frame 5 as a fulcrum. Can be tilted forward.

  Since all the components of the lock mechanism 48 are assembled into the seat frame 3 to form a unit, the assembling work is relatively easy.

  The seat frame 3 includes a seat frame main body 31 that holds the rear connection member 46 at the rear end portion 33 and supports the entire seat 4, and a front connection member 47 provided at the front end portion 34 of the seat frame main body 31. Since the seat forward tilting guide 32 is provided so as to be movable up and down, the lock mechanism 48 can be appropriately arranged on the seat frame 3.

  The lock mechanism 48 has one end 453 supported by the seat frame 3, and a gas spring 451 capable of changing the position of the other end 454 relative to the one end 453, and the position change of the other end 454 of the gas spring 451. 3 is provided with an operation converting portion 452 for converting the position of the front end portion 34 of the front end portion 34 into a vertical position change with respect to the front connecting member 47, so that the forward tilt state can be adjusted steplessly with a simple configuration, Fine adjustment is also possible according to the user's preference.

  The motion converting portion 452 includes a seat front tilt base 49 attached at one end 491 to the support base 2 via the front connecting member 47 so as to be movable back and forth, and an intermediate fulcrum 401 at the other end 492 of the seat front tilt base 49. And a seat front tilt adjustment arm 40 having one rotation end 402 connected to the seat frame 3 and the other rotation end 404 connected to the gas spring 451. Therefore, with a relatively simple configuration, a load applied from above the seat 4 is transmitted to the front connecting member 47, or conversely, the position change of the other end of the gas spring 451 is performed while no load is applied from above. Or transmitted to the tilt adjustment arm 40.

  A backrest 6 is supported by the support base 2 via a back frame 5 so that the backrest 6 can be tilted backward, and a chair C is supported by the support base 2 via a seat frame 3. 3 is supported by the support base 2 so as to be movable back and forth, and the rear connection member 46 held by the seat frame 3 is pivotally supported by the back frame 5 so that the backrest 6 Since the backward tilting operation and the sinking operation of the seat 4 are interlocked, a relaxed posture in which the user leans on the backrest 6 can be taken.

In particular, in this embodiment, since all the components of the lock mechanism 48 are assembled to the seat frame 3 and unitized, the lock mechanism 48 may interfere with each part that moves with the synchro-rocking mechanism R. Absent. Therefore, the chair C of this embodiment can coexist with the forward seat tilting means 45 and the synchro-rocking mechanism R. In other words, whatever the forward tilt state of the seat 4 is, the backrest 6 and the seat 4 can be locked without having to switch the forward tilt state of the seat 4.

  The seat 4 includes an outer shell 41 supported by the seat frame 3, a seat body 42 provided on the outer shell 41, and a depth changing means for changing a seating depth dimension of the seat body 42. The depth changing means is provided on the outer shell 41 so that the seat body 42 is slidable in the front-rear direction, and the seat body 42 is moved to a desired slide position by the slide positioning mechanism 44 and locked. It is something that can be done. Therefore, a better seating feeling can be given by changing the depth dimension of the seat 4 according to the physique of the seated person. That is, it is very difficult to make the depth dimension change compatible with the conventional case where only the front region of the seat is bent downward, but if the seat 4 as a whole is inclined forward as in the present embodiment. , It can be easily combined with the change of the depth dimension.

  The outer shell 41 has a load receiving surface 411 that receives a load from a seated person, and the load receiving surface 411 is formed around a sitting reference point T, and the sitting reference point T Further, since the inclined portion 412 that gradually rises forward is provided on the front side, the forward displacement of the seated person can be suppressed. In particular, if the seat 4 as a whole is tilted forward, if such an inclined portion 412 is provided, the heel portion is caught on the inclined portion 412, and it is possible to suppress shifting forward from the inclined portion 412. Is possible.

  In addition, even if the seating depth dimension is changed, the load receiving surface 411 does not move in conjunction with the seating depth dimension, so that a lot of people with different physiques can have a feeling of fit when seated. For example, if the person sits deeply on the seating surface of the seat 4 so that the back is attached to the backrest 6, the person who is seated can sit down even if the person is relatively large or small. The positions of are almost the same. And since a person with a relatively large physique has a long distance from the buttocks to the knee, it is often slid forward to enlarge the seating surface in the front-rear direction, but the conventional one has a load receiving surface on the inner shell side. Since it was provided, there was a problem that the position of the buttocks protruded forward with this forward sliding operation. On the contrary, if the load receiving surface of the inner shell is set in accordance with a person having a relatively large physique, it leads to a sense of discomfort for a person having a relatively small physique. For this reason, it was difficult to create a favorable seat for people of any size. However, since the seat 4 of this embodiment does not move the load receiving surface 411 in accordance with the sliding movement, an optimal fit can be given to many people with different physiques.

Furthermore, since the seat 4 of the present embodiment includes the inclined portion 412, it is possible to easily perform an operation of sliding the inner shell 421 backward with respect to the outer shell 41. Specifically, in the chair C provided with moving means such as the casters 13, when the inner shell 421 is moved forward relative to the outer shell 41, the seated person leans on the backrest 6 and puts this backrest 6 on the backrest 6. Although it is possible to perform a slide operation while pushing the waist forward while using it like a scaffold, it is relatively easy, but there is nothing that can be used like a scaffold when moving back relatively, so a seated person However, there is a problem that it is difficult to perform such a slide operation while sitting down. However, in the case of the present embodiment, when the load transmission portion 424 provided on the inner shell 421 receives a load from a seated person, the load transmission portion 424 and the load receiving surface are elastically deformed downward. 411 is in contact with the inner shell 421, so that when the inner shell 421 is moved relative to the outer shell 41, the seat occupant moves the load to the vicinity of the upper end of the inclined portion 412, and If the waist position is moved so as to apply weight, the inner shell 421 can be moved rearward in a manner like a slide using the weight of the seated person. Thus, by applying a seated person's load to the inclined part 412, the force which slides back arises and it can perform a back slide operation | movement easier than before.

  In addition, the chair C of the present embodiment has the rear connecting member 46 located in the vicinity of the sitting position reference point T, so that the height position of the buttocks, in other words, when the forward inclined state is switched. By doing so, the position of the eyes of the seated person is unlikely to change, and the uncomfortable feeling to the seated person can be reduced.

  The seat 4 includes the outer shell 41 and a seat body 42 having an inner shell 421 provided on the outer shell 41, and the inner shell 421 corresponds to the load receiving surface 411. A load transmission portion 424 for supporting a load from a seated person on the load receiving surface 411 is provided at the site. Therefore, the seating load from above is transmitted from the load transmitting portion 424 to the load receiving surface 411, and the load receiving surface 411 can firmly receive the load. Furthermore, there is an effect that the shape of the seating surface can be easily adjusted regardless of the shape of the outer shell 41.

  The present invention is not limited to the embodiment described above.

  The chair of the present invention may not have a backrest.

  Further, the seat forward tilting means may not include a lock mechanism, that is, may not lock the position of the front portion of the seat at a desired position in the vertical direction. The locking mechanism may use other urging means such as a spring member or a reaction force structure instead of the gas spring. However, if the gas spring is used as in the above-described embodiment, the locking mechanism is inclined forward. The state can be finely adjusted.

  The seat frame may be separate from the seat as in the above-described embodiment, or may be integral with the seat, for example, provided integrally with the seat outer shell.

  The rear connecting member may be any member as long as the seat rotates around the rear connecting member, and is not limited to the above-described shaft. In the above-described embodiment, the rear connecting member is indirectly supported by the support base via the back frame. However, the rear connection member may be directly supported by the support base.

  The front connecting member may be any member as long as it moves in accordance with the rotational movement of the front portion of the seat, and is not limited to the above-described shaft, and for example, a slider or the like may be applied. Good.

  In the embodiment described above, all the components of the lock mechanism are assembled to the seat frame to form a unit. However, in the case of a chair that does not have a synchro-rocking function, it is not always necessary to unitize the seat frame. For the same reason, the motion conversion unit does not necessarily have a seat tilting base. In the case of a chair that does not have a synchro-rocking function, for example, the intermediate fulcrum of the seat tilting adjustment arm is fixed to the support base. Alternatively, the seat tilt base may be fixed directly to the support base. However, in the present embodiment, it is not directly fixed to the support base in order to slide back and forth when the rear end side of the seat sinks due to the action of the synchro-rocking mechanism so as to be displaced in the front-rear direction with respect to the support base. The thing is adopted.

Furthermore, the chair of the present invention may not be provided with depth changing means, and may be provided with a load receiving surface or an inclined portion formed on the outer shell, or a load receiving surface of the inner shell. Of course it is good. Note that the depth changing means includes a front and rear slide type in which the entire inner shell moves in the front-rear direction relative to the outer shell as described above. A part that can be taken into a stretched state and a forwardly stretched state, or a portion in which the other shell provided at the front end of one shell moves relative to one shell in the front-rear direction A typical back-and-forth slide type is conceivable.

  In addition, various changes may be made without departing from the spirit of the present invention.

C ... Chair 1 ... Leg 2 ... Support base 3 ... Seat frame 33 ... Rear end 34 ... Front end 4 ... Seat (A) ... Standard posture (B) ... Forward tilt posture 41 ... Outer shell 411 ... Load bearing surface 412 ... Inclined portion 42 ... Seat body 421 ... Inner shell 424 ... Load transmitting portion 44 ... Slide positioning mechanism 45 ... Seat forward tilting means 452 ... Operation converting portion 453 ... One end 454 ... Other end 46 ... Rear connecting member 47 ... Front connecting member 48 ... Lock mechanism 6 ... Backrest T ... Sitting reference point

Claims (5)

The support base provided on the leg, the seat arranged on the support base, and the front end portion to the rear end portion of this seat are integrated from the standard posture to the forward leaning posture centering on the rear portion. A chair having a forward tilting means for tilting between the chairs,
The seat is provided with an outer shell and an inner shell provided on the outer shell, and the outer shell is provided with an inclined portion that gradually rises forward ,
The outer shell has a load receiving surface that receives a load from a seated person, and the load receiving surface is formed with a seating reference point as a center, and the front side of the seating reference point, A chair provided with the inclined portion . It said inner shell, according to claim 1 chair, characterized in that includes a load transfer portion for supporting the load from the seated person on the load bearing surface at a site corresponding to the load bearing surface. The chair according to claim 2 , wherein the load transmitting portion is configured to elastically deform downward and contact the load receiving surface when receiving a load from a seated person. The chair according to claim 2 or 3 , wherein a space is formed between a lower surface of the load transmitting portion and the load receiving surface. The chair according to claim 1, 2, 3, or 4, wherein the inner shell is arranged on the outer shell so as to be slidable in the front-rear direction within a predetermined range.

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