WO2008018117A1

WO2008018117A1 - Chair

Info

Publication number: WO2008018117A1
Application number: PCT/JP2006/315611
Authority: WO
Inventors: Nobutoshi Yamazaki; Kei Kawakami; Yoshiko Yagi; Nobuhiko Kitada; Hiroshi Takeuchi; Hiroyuki Ito
Original assignee: Itoki Corporation
Priority date: 2006-08-07
Filing date: 2006-08-07
Publication date: 2008-02-14
Also published as: CN101505634A

Abstract

A backrest (4) has a flexible back shell (4a). The upper end of the back shell (4a) is fitted to the upper end of a back support (19). A seat (3) is secured to a horizontal portion (20a) of the back support (19). The back support (19) is connected to a base (2) so as to be movable and tiltable backward. An auxiliary frame (40) is connected to the rear of the base (2) so as to be tiltable backward and is relatively movably connected to the back support (19). The lower portion of the back shell (4a) is held on the auxiliary frame (40) so that they can be relatively moved in the vertical direction and that they cannot be separated from each other in the backward and forward directions, and the lower portion of the back shell (4a) is pressed forward by a support body (54). When the backrest (4) and the seat (3) are tilted backward, the back shell (4a) is extended and deformed to a flat shape. Among portions of the seat (3), a seat front portion (3a) on which the thighs of the seated person is placed can be tilted forward about a connection pin (12). Consequently, swelling of a lower leg of the seated person can be suppressed by eliminating the compression on the thigh.

Description

Specification

Chair

Technical field

[0001] The present invention relates to a chair (synchronous chair) in which a backrest and a seat are interlocked and tilted backward. More specifically, the present invention relates to a chair suitable for women.

Background art

[0002] Rocking chairs whose backrests tilt backwards are often used for office rotary chairs, for example. There are two types of rocking chairs: the backrest only tilts backward, and the seat is tilted back and (Z or) backwards in sync with the backrest tilting. Many proposals have been made for a structure that tilts the backrest backward.

[0003] In addition, as the structure of the backrest, there is a net with a frame stretched around, but a thin back shell made of synthetic resin with a cushion attached to the front is often used. It is often attached to the back support (back strut) that is located behind.

[0004] For example, when an office chair is used by a person, a work mode (non-locking mode) in which the upper body is raised without tilting the backrest and the PC is operated, and a mode in which the backrest is tilted back and relaxed (Of course, this is a convenient classification, and some work may be done by leaning against the back.)

[0005] In a working state in which a seated person has raised his upper body, it is important to stretch his / her back and correct his / her posture, but the person who is seated when his pelvis is unstable is shy. Cheap. Therefore, the backrest is given a lumbar support function that supports the human pelvis and lumbar spine intensively. However, if the strong lumbar support function is exerted too much in the locked state, the person may be strongly pressed on the lower back, which may worsen the feeling of use.

[0006] An improvement proposal relating to this point is disclosed in Patent Document 1 which is the prior application of the applicant of the present application.

That is, in Patent Document 1, the backrest is formed in a structure that bends in side view, the backrest bends in a convex shape in side view in the non-locking state, and the entire backrest is flat in side view when locked. It is designed to be in the form. Further, the above In the claimed invention, the upper part and the lower part of the backrest that sandwich the bending point are fixed to separate links, and the shape of the backrest in a side view in the non-locking state and the locking state is changed by changing the degree of backward tilting of the link. Different.

Patent Document 1: Japanese Patent No. 3553301

Disclosure of the invention

Problems to be solved by the invention

[0007] By the way, when the inventors of the present application observed the use state of the chair, it was found that there was a difference in the use of the chair between men and women.

[0008] In other words, when a man uses a chair, he / she works in a posture that makes it retreat if the back is placed on the entire backrest (for example, keyboard operation or mouse operation), for example, on a desk. There is no psychological resistance to taking the elbow and working, taking a bad attitude, and taking a posture.

[0009] On the other hand, in the case of women, during work, the upper body is stretched and the posture where both knees are aligned is almost always taken. Is unlikely. In addition, there was a tendency to prefer a smaller back tilt angle. The reason why women prefer that the back tilt angle is small is mainly because women have weaker abs than men.

[0010] On the other hand, there is a problem of swelling of the lower leg as an obstacle complained by a woman who sits on a chair and works. The swelling is mainly caused by poor blood circulation. The reason why swelling of the lower leg is likely to occur in women is presumed as follows. In other words, for men, the blood circulation disorder does not appear so much because they take a relaxed posture at any time during work, such as spreading their legs or stretching their backs, but women align their knees to a chair and power their lower legs. In addition, it is presumed that there is a strong tendency to work in the same posture for a long time while pressing the thigh with a seating surface in a slightly forward tilted posture.

[0011] In recent years, women's work in the office has been centered on OA equipment operation work that operates the keyboard and mouse in opposition to the display. Swelling of the lower leg because the posture is often kept for a long time It can be said that this problem has appeared prominently in recent offices.

[0012] As described above, when observing the relationship between a woman and a chair, the conventional chair cannot always be said to have a form-mechanism suitable for a woman. However, in the past, it was said that there was almost no idea of giving a chair a function that is easy for women to use in terms of psychology and movement.

[0013] The present invention has been made in order to improve such a current situation, and an object thereof is to provide a chair suitable for women while partially following the idea of Patent Document 1. Means for solving the problem

[0014] The chair according to the present invention includes, as a basic configuration, a base attached to a leg, a seat supported by the base, a backrest to which a seated person can lean, and a back to which the backrest is attached. The seat and the back support are supported by the base so that they can tilt at least backwards against the spring means.

[0015] The backrest includes a flexible back shell that supports the body pressure of the seated person, and the back shell covers the waist of the seated person when the knock support and the seat are not tilted backward. It is greatly curved forward and convex in a longitudinal side view so that it can be supported in a concentrated manner, and when the back support and seat are tilted backward, it stretches and deforms so as to approach a flat state in the longitudinal side view. This is the first feature.

[0016] Further, the back shell is allowed to be stretched and deformed by attaching only the upper part to the back support so as not to be separated from the front and back, and the back support is tilted backward in conjunction with the back tilt of the back support. As a result, an auxiliary frame that stretches and deforms the back shell is connected. This is the second feature. The back support of the present invention means a member to which the backrest is attached, and it does not mean that it constitutes the rear part of the seat chair.

[0017] According to the present invention, a person sitting in a posture in which the upper body is raised raises the spine while holding the center of gravity of the upper body directly above the pelvis by placing the waist (lumbar vertebrae) on the forward convex part of the backrest. You can continue to maintain your correct posture comfortably. Furthermore, by pushing the seated person's lumbar vertebrae with the convex part of the backrest, the upper body of the seated person will bend up with his chest raised, and as a result, his head will wake up, Because of this, the beauty that stretched back It can be used for a long time with a long posture, and is therefore particularly suitable for women.

[0018] Further, in the rocking state, the backrest is flattened and deformed flatly in a side view in the longitudinal direction (finally, it may be flattened or loosely curved). However, it is possible to obtain a comfortable rocking state in which the waist and back are evenly supported with a feeling of pushing up against the waist. This aspect is also suitable for women.

[0019] (1). Variation 1 of the present invention

The present invention has various nourisions. In the first noriation, the auxiliary frame is set to tilt backward to a greater degree than the back support, and the auxiliary frame and the lower part of the back shell (that is, the apex of the forward convex curved portion). The lower part) is connected in a state where it can move in the vertical direction and cannot be separated in the front-rear direction, and the auxiliary frame tilts backward to a greater degree than the back support. The back shell is stretched and deformed.

[0020] (2). Variation 2 of the present invention

In the second norelation, the seat and the back support are fixed to each other so as to be tilted backward and backward together, and the tilting fulcrum of the seat and the back support is located at the front portion of the base, while The auxiliary frame is connected to the rear part of the base and the back support, and the auxiliary frame is positioned to the rear of the tilting fulcrum of the seat and the back support so that the auxiliary frame is larger than the knock support. I started to lean backwards with V!

[0021] (3). Variation 3 of the present invention

In a third variation, the back support includes a horizontal portion extending to the vicinity of the front portion of the base below the seat, and a longitudinal axis provided on the base by a support shaft provided at the front portion of the horizontal portion. It is connected to the horizontal bearing part so that it can be tilted backward and backward, the seat is fixed to the horizontal part of the back support, and the auxiliary frame is connected to the rear part of the base so that it can tilt backwards. Has been.

[0022] In a chair in which the back support and the seat are tilted backwards like the chair of the present invention, the seat and the back support are not tilted backward only by sitting, and the person leans on the backrest. It is necessary for the back support (back) and the seat to tilt backward (or back and back). In a synchro-type chair, as a means for connecting the seat to the base so that it can be tilted backward and backward, a support shaft is attached to the seat (or a bracket to which the seat is fixed), and the length of the support shaft that is open to the base is long. In general synchro-chairs, which are often slidably fitted into the holes, the long holes in the base are formed in a backward tilted position when viewed from the side, so that the seat ascends and retracts while descending as a whole. It starts to move!

[0023] However, in this conventional configuration, the shaft slides through the long hole of the base by sitting down, and the strength of the spring that supports the shaft must be increased. Then, when the resistance to locking increases, there is a problem. On the other hand, according to the third noriation of the present application, since the support shaft is fitted and the bearing portion is horizontal, the load due to the seating does not act to slide the support shaft, and the auxiliary frame Since it is connected to the rear part of the base, the load caused by the seating does not act to tilt the auxiliary frame backwards. Can be prevented from tilting backward. For this reason, it is possible to prevent the seat from being tilted backward or depressed due to the seating while ensuring the ease of locking. Generally, women are lighter in weight than men, so it is preferable that springs that provide resistance to mouth opening are weaker than those used by men. However, the third nomination of this application is considered as a chair for women. RU

[0024] (4). Variation 4 of the present invention

In the fourth norelation, the auxiliary frame is provided with a support body that also supports the back side force of the apex portion of the forward convex curved portion of the knock shell. By providing a support body in the auxiliary frame, even if the knock shell has flexible material strength, the human waist is firmly supported without being deformed by body pressure. If the support body is formed in a roller shape, the relative movement between the auxiliary frame and the back shell becomes smooth, and as a result, the back shell is reliably deformed as the back support tilts. Therefore, the support body is preferably formed in a roller shape.

[0025] The present invention also has a norelation relating to the seat. In the fifth Noriation, the front seat is divided into a front seat portion and a rear seat portion with a bent portion extending in the left-right direction, and the front seat portion can be tilted forward about the bent portion. Before and after the front seat The width dimension is set to a dimension larger than 1Z4 and smaller than 1Z2 of the front and rear width dimension of the entire seat, and the seat front portion is stepwise or steplessly changed to a side view posture by turning the lever. It is supported by a member arranged below the seat so that it can be changed.

[0026] (5). Variations of the present invention 5, 6

As mentioned above, the problem of swelling of the lower leg of a woman in the office is a serious force. When the fifth noriation configuration is adopted, the front seat is tilted forward to eliminate pressure on the thigh. Thus, swelling of the lower leg can be eliminated or significantly suppressed. What is particularly important here is that the front-rear width dimension of the front part of the seat is larger than the front-rear width dimension of 1Z4 and smaller than 1Z2. With this dimension, the pelvis can be effectively restrained from pressing on the thigh while being held stable in the back of the seat.

[0027] In the sixth nori cation of the present application, the front end portion of the seat is recessed in a forward concave shape in plan view. When the front end of the seat is recessed in a forward-facing concave shape in plan view, the seated person receives a guide action that moves both knees toward the center line of the seat, and as a result, aligns both knees. It becomes easy to hold the posture. In this regard, it is a form for women who prefer to sit with both knees aligned.

[0028] Further, it is preferable to sit as deep as possible in order to accurately support the human waist with the forward convex part of the backrest, but it is uncomfortable if the back of the knee hits the front edge of the seat by sitting deeply. Women often take a posture with their shins in the lower part of the seat, so the back of the knee is particularly likely to hit the front edge of the seat. However, according to the sixth nomination of the present application, since the front end of the seat is recessed in plan view, it is possible to sit deeply while preventing the back of the knee from hitting the front end of the seat. This sixth development invention is also considered as a chair suitable for women.

Brief Description of Drawings

[0029] FIG. 1A is a front view of a chair, and FIG. 1B is a side view of the chair.

[FIG. 2] FIG. 2A is a plan view of the chair, FIG. 2B is a sectional view taken along the line IIA-IIA in FIG. 1A, and FIG. 2C is a rear view of the chair.

FIG. 3A is a longitudinal side view of a chair, and FIG. 3B is a longitudinal side view of a seat and a backrest.

FIG. 4 is a plan view with the seat omitted. FIG. 5 is a perspective view of members constituting the locking mechanism.

FIG. 6 is an exploded perspective view of the base and the lower receiving member.

7 is a cross-sectional view taken along the line VII-VII in FIG.

8 is a cross-sectional view taken along the line VIII-VIII in FIG.

FIG. 9 is an exploded perspective view of a seat inner shell.

FIG. 10 is a schematic perspective view of an outer shell.

FIG. 11 is an exploded perspective view of members constituting the back part.

[Fig. 12] Fig. 12A is a partially broken front view of the backrest, Fig. 12B is a sectional view taken along the line B-B in Fig. 12A with the cushion omitted, and Fig. 12C is CC in Fig. 12A with the cushion omitted. FIG.

FIG. 13 is an exploded perspective view of members constituting the back part.

[FIG. 14] FIGS. 14A and 14B are perspective views in the assembled state of the members constituting the locking mechanism, FIG. 14A is a view with the front cover removed, and FIG. 14B is a state with the front cover removed. FIG.

FIG. 15 is a partial vertical side view of the back.

FIG. 16A is a conceptual diagram for explaining the movement of the backrest and the seat, and FIG. 16B is a conceptual diagram showing the lumbar support function.

FIG. 17 is an exploded perspective view showing the support mechanism portion of the seat front portion.

FIG. 18 is a plan view showing a support mechanism part of a seat front part.

FIG. 19 is a cross-sectional view taken along the line XIX-XIX in FIG.

20 is a cross-sectional view taken along the line XX-XX in FIG.

Explanation of symbols

1 leg

2 base

3 seats

3a seat front

3b rear seat

4 Backrest 4a Nocxenore

9 Seat front inner shell

10 Rear inner shell

12 Connecting pin

19 Back support

20 Pipes that make up the knock support

20a Horizontal section

20b spine

22 First spindle

26 Lower bearing member

27 Upper bearing member

31 Spring for locking

34 Front lever for tilting the front seat

35 Bearing member for tilting support of seat front

36 Cam member

40 Auxiliary frame

42 Second spindle

49 Third spindle

54 Push the back shell from the back Support body

56 Guide pin

BEST MODE FOR CARRYING OUT THE INVENTION

Next, an embodiment of the present invention will be described with reference to the drawings.

[0032] (1). Overview of chairs

First, an outline of the chair will be described with reference to FIGS. The chair includes a leg 1, a base 2 attached to the upper end of the leg 1, a seat 3 disposed above the base 2, and a backrest 4 disposed behind the seat 3. The leg 1 includes a pedestal 5 that also has a gas cylinder force, and branch legs 6 that extend radially from the pedestal 5, and a caster 7 is provided at the tip of each branch leg 6. The lock of the pedestal 5 can be released by operating the lever 8 (see FIG. 1A) provided on the base 2. [0033] As shown in Figs. 3A and 3B, the seat 3 includes front and rear seat inner shells (seat plates) 9 and 10 made of resin and cushion bodies 11 stretched so as to extend in series on the upper surfaces thereof. Therefore, the seat 3 comprises a seat rear portion 3b that does not move unless it is locked, and a seat front portion 3a that can be tilted forward. As will be described in detail later, the front inner shell 9 and the rear inner shell 10 are connected by a horizontally long connecting pin 12, and the seat front portion 3a can be tilted forward with the connecting pin 12 as the center.

[0034] The backrest 4 has a structure in which a cushion 4b is stretched on the front surface of a synthetic resin back shell 4a, and a back cover 13 extending over almost the entire height of the back shell 4a is provided behind the back shell 4a. (Back cover 13 is fixed to back support 19 to be described later.) O The backrest 4 has a side guard section ^ that protrudes so as to wrap the waist of the person sitting on both sides. Yes. The main reason for the side girth section is to improve the posture stability of the seated person, and the seated person wears roller's pants, and the waist skin is exposed. If you can not see the external force! /, Is to cover

[0035] The space between the knock cover 13 and the base 2 is closed by the rear cover 14, and a front cover 15 is mounted in front of the base 2, and the front cover 15 is provided on both left and right sides. The front lever knob 16 for tilting the seat front part 3a is exposed (details will be described later). The front cover 15 is attached to the front inner shell 9 of the seat 3. Reference numeral 17 shown in FIGS. 1 and 2 is a lever that switches the backrest 4 between a state in which the backrest 4 can be tilted backward and a state in which the backrest cannot be tilted.

[0036] (2). Seat and its supporting mechanism

Next, the seat 3 and its support mechanism will be described with reference to FIGS. The base 2 has a nosing shape that opens upward, and a back support 19 to which a seat 3 and a backrest 4 are attached is connected to the base 2 as shown in FIG. The back support 19 includes two left and right pipes 20 as main members. The pipe 20 is composed of a horizontal portion 20a that is positioned below the seat 3 and extends in the front-rear direction, and a back column 20b in which the rear end force of the horizontal portion 20a rises upward!

[0037] The front ends of the left and right pipes 20 constituting the knock support 19 have an open groove type facing upward as viewed from the front. The front bracket 21 is fixed by welding. The left and right front brackets 21 are fixed to the left and right horizontally long first support shafts (also called slide shafts) 22 by welding, and the horizontal portions 20a of the left and right pipes 20 are The connecting portion 23 and the second connecting body 24 are integrally connected. The first support shaft 22 is disposed below the horizontal portion 20 a of the pipe 20.

[0038] As shown in FIG. 3, an outer shell 25 made of grease is provided below the rear inner shell 10, and the rear inner shell 10 is detachably fixed to the outer shell 25. The outer shell 25 is fixed to the first connecting body 23 of the knock support 19 with screws or the like.

[0039] As shown in FIG. 9, the front inner shell 9 has a shape close to a substantially flat plate. On the other hand, the rear inner shell 10 is gently bent in an upward concave shape in a front view, and is gently curved in an upward concave shape in a longitudinal front view. The front and rear inner shells 9 and 10 are connected to the pair of left and right cylindrical bearing portions 9a and 10a and the semicircular bearing portions 9b and 10b so that they can be bent. The connecting pin 12 (in other words, the first support shaft 22 is positioned in front of the bending point of the seat front 3a.) Slightly it is positioned behind the first spindle 22 ₀

[0040] In this embodiment, the front and rear inner shells 9, 10 are connected and then the cushion 11 is integrally formed by the insert molding method. The cushion 11 can be separately manufactured and attached. . The outer shell 25 is disposed directly below the rear inner shell 10, and the rear inner shell 10 is moved to the outer side by fitting the claw-like engaging portion 25 a of the outer shell 25 and the hole-like engaging portion 10 c of the rear inner shell 10. It is attached to the shell 25.

[0041] As can be understood from FIGS. 4, 7, and 8, the first support shaft 22 of the back support 19 is sandwiched between a lower bearing member 26 and an upper bearing member 27 that overlap each other in the vertical direction. The holding member 28 is overlapped with the member 27, and these three members are fastened together with screws (not shown) to the base 2 in a state of being overlapped with each other! RU

For example, as shown in FIG. 5 and FIG. 6, the lower bearing member 26 has four front and rear, left and right engagement holes 29 penetrating vertically, while the base 2 has the engagement holes 29 described above. The boss body 2a that fits tightly is formed in the body, and by inserting the lower bearing member 26 into the boss body 2a, The lower bearing member 26 is held immovable in the horizontal direction. The pressing member 28 is fastened to the boss body 2a with screws.

[0043] The base 2 is formed with a center protrusion 2b where the rear end of the lower bearing member 26 comes into contact, a hole 2c into which the pillar 5 is fitted, an overhanging portion 2d for attaching an armrest (not shown), and the like. The base 2 and the upper and lower bearing members 26 and 27 are die-cast products such as aluminum, and the pressing member 28 is a sheet metal product. However, the material and processing method of these members can be arbitrarily selected.

For example, as can be understood from FIG. 8, the upper and lower bearing members 26 and 27 are formed with long grooves 30 that allow the first support shaft 22 to slide back and forth. The upper and lower elongated grooves 30 are elongated by overlapping each other. A spring (compression coil spring) 31 is disposed between the upper and lower bearing members 26 and 27, and a rear wall 32 is formed at the rear end of the lower bearing member 26 to support the spring 31 with a rearward force. . On the other hand, a front spring support 33 that supports the spring 31 forward is overlapped with the first support shaft 22 of the knock support 19.

Accordingly, the knock support 19 (and the seat 3 and the backrest 4) can slide backward against the spring 31 and can tilt backward about the first support shaft 22. The long grooves (long holes) 30 of the upper and lower bearing members 26, 27 extend in the horizontal direction. For this reason, even if the spring force of the spring 31 is not excessively large, the seat 3 cannot be tilted backward only by a person sitting on the seat 3.

[0046] It is also possible to directly attach the first support shaft 22 to the base 2 without using the vertical shaft bearing members 26, 27, and the first support shaft 22 is connected to the back support 19. It is also possible to manufacture the first support shaft 22 separately and fit the first support shaft 22 into a long hole formed in the base 2.

As shown in FIG. 4, a bearing member 35 for holding the front lever is attached to the front end portion of the left and right front brackets 21, and the cam member 36 is attached by the bearing member 35. Support. Details of this point will be described later.

[0048] (3). Backrest and locking structure

Next, the backrest 4 and the locking structure will be described with reference to FIGS. 11 to 15 in addition to FIG. As described above, the backrest 4 is provided with a back shell 4a made of greaves and a cushion 4b stretched on the front surface thereof (a bag-like cloth is also stretched). As shown in FIG. 12A, the knock shell 4a has a number of horizontally long slits 38. The shell 4a retains flexibility so that the shape of the longitudinal side view can be easily changed.

[0049] As shown in Fig. 11 and Figs. 14A and 14B, the upper ends of the left and right back struts 20b are connected by an upper connecting body 39 having a cross-sectionally rearward opening groove type, and the upper end portion of the back shell 4a is connected to the upper connecting body. It is attached to 39 so that it cannot be separated. Specifically, as shown in FIG. 12B, a locking portion 4c is formed on the upper part of the knock shell 4a, and the locking portion 4c is fitted to the upper coupling body 39.

[0050] As shown in FIG. 3A and FIG. 13, an auxiliary frame 40 having a substantially L-letter shape in a side view with two left and right pipe members as main members is disposed as a part of the locking mechanism. The frame can also be referred to as a rear frame or a link.) _{0 The} left and right horizontally elongated second support shafts 42 are integrally fixed to the front ends of the left and right pipes constituting the auxiliary frame 40 via the bracket plate 41. ing.

[0051] As shown in FIG. 3A, the second support shaft 42 is sandwiched between the rear part of the base 2 in a state where it can be rotated by upper and lower split bearings 43, 44, and the bearings 43, 44 are The holding member 45 is fixed to the base 2 with screws. Therefore, the auxiliary frame 40 can tilt about the third support shaft 42. The auxiliary frame 40 may be connected to the base 2 with a pin. In Fig. 3, the bearings 43 and 44 should originally be displayed in cross section, but the cross section display (hatching) is not performed because of the complexity. In FIG. 13, only the upper bearing member 43 is shown.

For example, as shown in FIG. 13, a third connector 46 made of a metal plate is fixed to the lower part of the left and right pipes constituting the auxiliary frame 40, and the upper ends of the left and right pipes A fourth connector 47 made of a metal plate is fixed to the body. The third connecting body 46 includes a forward groove, 46a, and upper and lower blades 46b, while a third support shaft 49 is fixed to the lower body of the left and right back struts 20b via a bracket material 48.

Then, as clearly shown in FIG. 15, the third support shaft 49 is rotatably sandwiched between upper and lower split-type bearing bodies 50 and 51, and the front and rear bearings 50 and 51 are held together by the holding force 52. It is fixed to the third connecting body 46 via Accordingly, the knock support 19 (back strut 20b) and the auxiliary frame 40 rotate in conjunction with each other. The rear bearing 50 is fitted in the forward groove 46a of the third connecting body 46, and the holding member 52 is fixed to the blade 46b of the third connecting body 46 with screws. Yes.

For example, as shown in FIG. 13, the fourth connecting body 47 in the auxiliary frame 40 is formed with a pair of left and right bearing pieces 47a extending upward, and is inserted into the left and right bearing pieces 47a. A roller-shaped support body 54 is rotatably fitted to the pin 52, and the support body 54 is brought into contact with the back surface of the back shell 4a. The support body 54 is separated into the left and right, and the left and right support bodies 54 are rounded and truncated cone-shaped so that the portion close to the center of the backrest 4 has a small diameter ( As a whole, the central part is constricted.)

[0055] The portion of knock shell 4a where the seated person hits is curved in a forwardly convex shape in a side view so that the portion on which support body 54 hits is located closest to the front. As shown in FIG. 16B, the forward apex portion 4 of the knock shell 4a is substantially the same height as the third lumbar vertebra Y3 of the seated person.

[0056] As shown in FIG. 3A, a box-shaped bracket projecting rearward is formed in a portion of the back surface of the back shell 4a located between the third connecting body 46 and the fourth connecting body 47 of the auxiliary frame 40. The left and right lateral guide pins 56 are formed integrally with each other via the section 54. (The guide pins 56 may be a separate member from the back seal 4a.) O

On the other hand, as shown in FIG. 15, the guide body 57 in which the guide pin 56 of the backrest 4 is fitted to the third connecting body 46 and the fourth connecting body 47 of the auxiliary frame 40 is fixed with screws! / RU The guide body 57 has a guide groove 57a which is vertically long and has a lower portion opened forward. The guide groove 57a and the guide pin 56 are fitted, so that the knock shell 4a is separated forward from the auxiliary frame 40. It is held (locked) so that it cannot move and can move up and down. The reason why the lower portion of the guide groove 57a is opened forward is to allow the guide pin 56 to be fitted / removed also with the front side force.

[0058] As can be understood from FIG. 13 and FIG. 14A, the auxiliary frame 40 is covered from the front by an auxiliary cover 58, and as shown in FIG. 14B, the support body is a support body among the mechanism portions that support the backrest 4. The portion excluding the periphery of 54 is covered with a front cover 59. The front cover 58 has a window hole 59a for exposing the substantially upper half of the auxiliary cover 59. The back cover 13 is provided with a claw for attaching it, but the display is omitted in FIG. Figure 14A As shown, the hanger 60 can be attached to the upper connecting body 39 of the back support 19.

[0059] As can be understood from FIG. 3, the auxiliary frame 40 is attached to the base 2 at a position near the rear end of the seat 3, and therefore, the rotation fulcrum of the auxiliary frame 40 is a person. It is shifted backward from the center point (position indicated by the black arrow in Fig. 3A) where the load is applied when seated. For this reason, when the person is seated and the backrest 4 is not leaning against the backrest 4, the knock support 19 is supported by the auxiliary frame 40 so that the rearward force is also supported upward. This prevents the first spindle 22 from moving backward.

[0060] (4). Lumber support function 'seat and backrest movement

Next, the function of the back 4 and the movement of the seat 3 and the back 4 will be explained. In the non-locking state, as shown in Fig. 16B, the backrest 4 is greatly curved forward and convex in a longitudinal side view, so that the seated person's lumbar vertebra Y (especially the third lumbar vertebra Y3) is Therefore, the stability of the seated person's pelvis and spine is high. As a result, a person can sit down for a long time without getting tired in a posture in which the back is stretched.

[0061] Further, since the forward apex 4a 'of the backrest 4 is supported by the support body 54 with the back force, the forward apex 4 of the backrest 4 is dented by the human body pressure or the degree of curvature is reduced. There is nothing. For this reason, the lumbar support function can be maintained with great strength.

Next, the movement of the seat 3 and the backrest 4 will be described. In this embodiment, since the seat 3 and the backrest 4 are attached to the back support 19, the seat 3 and the backrest 4 integrally move backward and backward, and the degree of the rearward tilt of the knock support 19 The degree of backward tilting of seat 3 is consistent.

[0063] Since the auxiliary frame 40 and the back column 20b (back support 19) are connected, the auxiliary frame 40 tilts backward in conjunction with the rearward tilt of the back column 20b, but the auxiliary frame 40 rotates. Since the fulcrum is located behind the rotation fulcrum of the back column 20b, the auxiliary frame 40 tilts backward at a larger angle than the back column 20b. Further, since the back support 19 also moves backward, the auxiliary frame 40 tilts backward while being pushed backward, and this also causes the auxiliary frame 40 to tilt backward to a greater degree than the back column 20b.

[0064] Therefore, while the support body 54 and the back column 20b are both inclined backward, the support body 54 is supported by the back support. It will tilt backward relative to the pillar 20b. In the lower part of the knock shell 4a, the guide pin 52 is fitted in the guide member 57 and is held so as not to be separated from the front and rear with respect to the auxiliary frame 40. When retreating, the back shell 4a is subjected to the action of pulling downward, and the shape force that is greatly bulged forwardly convex in a longitudinal side view is close to a flat shape and deformed to a shape. For this reason, it is comfortable for a person who feels that the person's back and hips are pushed up in a rocking state.

[0065] Further, when the backrest 4 extends and deforms while tilting backward, the backrest 4 tilts backward at a larger angle than the seat 3, and therefore the seat 3 and the backrest 4 are supported by the back support 1 9 Despite being attached to the backrest 4, the backrest 4 can be tilted backward enough to ensure a comfortable rocking condition.

[0066] In the present embodiment, the bracket portion 55 of the back shell 4a has a small vertical dimension! /. Therefore, the lower portion of the back shell 4a is easily deformed. For this reason, the back shell 4a is naturally rounded. You can be in a waiting state. For this reason, it has good fit to the human waist

[0067] (5). Front seat support mechanism

Next, a support mechanism for the seat front portion 3a will be described mainly with reference to FIGS. The front bracket 21 of the knock support 19 constitutes a part of the support means of the seat front portion 3a, and the front bracket 21 is a hook-like protruding portion that protrudes forward from the horizontal portion 20a of the pipe 20. 21a.

[0068] On the projecting portion 21a of the left and right front brackets 21, a bearing member 35 is overlaid. The bearing member 35 includes a side plate 35a positioned on the left and right outer sides, a support surface 35b positioned on the inner side of the side plate 35a, a downward projecting portion 35c that fits into the groove of the hook-shaped projecting portion 14a, and a lower portion of the pipe 13 A rear-facing convex part 35d, an inwardly extending piece 35e projecting inward from the left and right sides, and a back plate 35f that contacts the front of the front bracket 14, and the rearward convex part 35d is connected to the front bracket 21 by a pin 62. Te!

Accordingly, the bearing member 35 is held so as not to change its posture with respect to the front bracket 21. The support surface 35b of the bearing member 35 has a horizontal base end and an inclined surface on the front side. [0070] The posture of the seat front portion 3a is changed by the rotation of the front lever 34. The front lever 34 includes a left and right central shaft 34a that fits into a bearing hole 63 formed in the side plate 35a of the bearing member 35, a center crank 34b that is bent between the left and right central shaft 34a, and the outer side of the left and right central shaft 34a. The formed side crank 34c and the hook part 34d bent at the tip of the side crank 34c are also made of force, and the knob 16 described above is fixed to the hook part 34d.

[0071] The projecting direction of the center crank 34b and the projecting direction of the side crank 34c are shifted by approximately 90 degrees when viewed from the axial direction of the central shaft 35a. While the corner of the front lever 34 is slightly rounded, the side plate 35a of the bearing member 35 is thin, so the front lever 34 can fit its center shaft 34a into the bearing hole 63 of the bearing member 35. .

[0072] As shown in FIG. 19, cam members 36 are also fitted to the left and right ends of the center crank 34b of the front lever 34 with an external force. The cam member 36 includes a long hole 36a in which the center crank 34b of the front lever 34 is slidable in a direction perpendicular to the axis thereof, and is formed in a substantially flat cylindrical shape, and one end portion is a support surface of the bearing member 35. It is listed in 35a. The cam member 36 rotates about its base end, and takes a posture of an upright posture that overlaps with the back plate 35f of the bearing member 35 and a forward tilted posture (horizontal posture) that overlaps the inclined portion of the support surface 35b. Can be changed. A stopper projection 65 for holding the cam member 36 in an upright posture is formed on the lower surface of the front inner shell 9 in the seat 3.

[0073] As shown in FIG. 20, the front inner shell 9 has a front-side and left-right middle portion with arcuate guide holes 66 in a side view arc shape into which the left-right middle portion of the center crank 34b of the front lever 34 is fitted. Is provided. The guide hole 66 is formed by forming a downwardly concave upper guide surface 67 on the front inner shell 9 and attaching an upwardly concave lower guide body 68. It is fitted in the engagement hole 69 formed in the inner shell 9.

[0074] By rotating (rotating) the front lever 34 via the knob 16 to change the cam member 36 between the upright posture and the forward tilted posture, the seat front portion 3a is not tilted forward. The posture is changed between the normal posture and the forward leaning posture (see the dashed line in Fig. 20). In this case, the forward tilt angle is preferably about 10 to 15 degrees. For example, it is possible to select a structure that can hold multiple anteversion postures, such as fixing the anteversion angle in increments of 5 degrees. [0075] Since the cam member 36 overlaps the inclined support surface 35b of the bearing member 35 in the forward inclined posture of the seat front portion 3a, the forward inclined posture of the seat front portion 3a is maintained. When the cam member 36 is tilted, the cam member 36 gets over the topper protrusion 65 by pushing up the front inner shell 9.

[0076] The dimensional relationship between the seat front part 3a and the seat rear part 3b of the seat 3 is shown in Fig. 3B. If the overall front-rear width dimension of the seat 3 is WO, and the front-rear width dimension of the seat front 3a is W1, then (1 / 4-W0) <W1 <(1 / 2-W0), and W1 is The actual size is preferably about 200mm. Further, it is preferable that the connecting portion (the axial center of the connecting pin 12 which is the center of bending) is located in front of the portion 31 / force where the rear seat portion 3b is most recessed 90-: L 10 mm. The most recessed part 3b ′ of the seat rear part 3b is located behind the front-rear center position of the seat 3 as a whole.

[0077] (6). Other

The embodiments of the present invention are not limited to those described above, and can be embodied in other various forms. For example, the shape of each member such as a base, a seat, a knock support, an auxiliary frame, and a backrest can be any shape as long as the function is maintained. For example, both the knock support and the auxiliary frame can be made of sheet metal products or die-cast products.

[0078] In addition, the horizontal portion of the knock support located below the seat may be a die-cast product or a sheet metal product, and the back strut may be a pipe. The present invention can also be applied to a chair in which the seat only tilts backward in conjunction with the backrest.

Claims

The scope of the claims

[1] It comprises a base attached to a leg, a seat supported by the base, a backrest on which a seated person can bend or force, and a back support to which the backrest is attached. Is supported by the base so that it can tilt at least backwards against the spring means,

The backrest has a flexible backshell that supports the body pressure of the seated person, and the knock shell supports the seated person's waist intensively when the knock support and the seat are not tilted backward. As shown in the figure, it is greatly curved in a convex shape when viewed from the longitudinal side, and when the back support and seat are tilted backward, it stretches and deforms so as to approach a flat state when viewed from the longitudinal side.

A chair called

The back shell is allowed to be stretched and deformed by attaching only the upper part to the back support so that it cannot be separated from the front and back, and the back support is tilted backward in conjunction with the back tilt of the back support. An auxiliary frame that stretches and deforms the back shell is connected,

Chair.

[2] The auxiliary frame is set to tilt backward with a greater degree than the back support, and the auxiliary frame and the lower portion of the back shell are relatively movable in the vertical direction and separated in the front-rear direction. The back shell is stretched and deformed when the auxiliary frame tilts backward to a greater degree than the knock support.

The chair according to claim 1.

[3] The seat and the back support are fixed to each other so as to be tilted backward and backward, and the tilting fulcrum of the seat and the back support is located at the front portion of the base, while the auxiliary frame is The auxiliary frame is connected to the rear part of the base and the back support, and the auxiliary frame is positioned to the rear of the tilting fulcrum of the seat and back support by positioning the auxiliary frame with respect to the base to a greater degree than the back support. Is leaning, The chair according to claim 2.

[4] The back support is provided with a horizontal portion extending to the vicinity of the front portion of the base below the seat, and the support shaft provided at the front portion of the horizontal portion has a horizontal shape in the longitudinal direction provided on the base. The seat is fixed to the horizontal portion of the back support, and the auxiliary frame is connected to the rear portion of the base so as to be able to tilt backward. ,

The chair according to claim 3.

[5] The auxiliary frame is provided with a support body that supports the apex portion of the forward convex curved portion of the knock shell from the back side.

The chair according to claim 1.

[6] The seat is divided into a front seat portion and a rear seat portion with a bent portion extending in the left-right direction interposed therebetween, and the front seat portion can be tilted forward about the bent portion, The front / rear width dimension of the front part of the seat is set to be larger than 1Z4 and smaller than 1Z2 of the front / rear width dimension of the entire seat, and the front part of the seat is viewed from the side by rotating the lever. The chair according to claim 1, wherein the chair is supported by a member arranged below the seat so that the step can be changed stepwise or steplessly.

[7] The front end portion of the seat is recessed in a forward-facing concave shape in plan view.

The chair according to claim 6.