CN101505634A - Chair - Google Patents

Abstract

A chair, wherein the backrest (4) has a flexible back shell (4a), the upper end of the back shell (4a) is mounted on the upper end of a back support (19). The seat (3) is fixed on the horizontal portion (20a) of the back support (19), and the back support (19) is connected to the base (2) in a way that can retreat and tilt backward. The auxiliary frame (40) is connected to the rear part of the base body (3) in a reclinable manner, and the auxiliary frame (40) is connected to the back support (10) in a relatively movable manner. The lower part of the back shell (4a) is held so that it can move up and down relative to the auxiliary frame (40) and cannot be detached back and forth, and is pressed forward by the support body (54). If the backrest (4) and the seat (3) tilt backward, the back shell (4a) stretches and deforms towards the flat shape. The front part (3a) of the seat (3) carrying the thighs of the seated person can be tilted forward centering on the coupling pin (12). Therefore, pressure on the femur of the seated person can be eliminated, and swelling of the calf can be suppressed.

Description

Chair

technical field

The invention relates to a chair (synchronous chair) in which the backrest and the seat are linked and reclined. In particular, the present invention relates to chairs suitable for women.

Background technique

A rocking chair with a tilting backrest, such as a swivel chair for office use. The rocking chair has a type in which only the backrest tilts back and a synchronous type in which the seat and the backrest tilt backward and/or move backward in conjunction with each other. Also, there are many proposals regarding the structure for tilting the backrest.

Also, as the structure of the backrest, there are some that set up a net on the frame, but most of them use a thin back shell made of synthetic resin to set up a cushion body on the front, and the back shell is often attached to a back support ( back support).

For example, when a person uses an office chair, there is a work mode (non-swing mode) in which the backrest is not tilted back and the upper body is straightened to perform work such as personal computer operations (non-swing mode) and a mode in which the backrest is tilted back and relaxed (swing mode) (of course, this is a handy assortment, and sometimes leans on the backrest for some sort of work).

When the seated person straightens the upper body, it is important to straighten the back and adopt the correct posture. However, if the pelvis is unstable, the seated person is prone to hunchback. Therefore, it is necessary to make the backrest have the health-care and waist-protecting function of supporting people's pelvis and lumbar vertebrae intensively. However, if the strong health-care waist protection function is exerted too much in the swing state, the waist of the person will be strongly oppressed, and the usability may deteriorate instead.

An improvement on this point is disclosed in Patent Document 1 previously filed by the present applicant. That is, in Patent Document 1, the backrest is formed into a curved structure in a side view. In the non-swing state, the backrest is convexly curved in a side view. Specifically, in the invention of the above-mentioned previous application, the upper and lower parts of the backrest sandwiching the bending point are fixed to the respective connecting rods, and by changing the reclining degree of the connecting rods, the backrest can be moved from the non-swaying state to the swinging state. The shape is different when viewed from the side.

Patent Document 1: Patent No. 3553301

Contents of the invention

The problem that the invention intends to solve

However, the present inventors observed the use state of the chair and found that the use of the chair is different for men and women.

That is, when a man uses a chair, it is not appropriate to take a so-called reclining posture with his back resting on the backrest (for example, keyboard operations, mouse operations), or for example, to lean his elbows on a table. Good posture has no psychological resistance, and it likes to make the backrest recline greatly in a rocking state.

On the other hand, in the case of women, they almost always adopt the posture of straightening the upper body and tucking the knees in the work, and do not adopt the posture of leaning back on the backrest or leaning the elbows on the table. Also, it can be found that the reclining angle of the backrest is very small. It can be said that the main reason why women like the reclining angle of the backrest is small is that women have weaker abdominal muscles than men.

On the other hand, as an obstacle for women who work while sitting on a chair, there is a problem of swelling of the calf. The main cause of swelling is the deterioration of blood circulation, and the reasons why women are prone to calf swelling are speculated as follows. In other words, it can be speculated that in the case of men, they will open their legs and straighten their backs to take a relaxed posture at any time during work, so blood circulation disorders do not occur much, while women will keep their knees on a chair and their calves will not move. , and there is a strong tendency to work in the same posture for a long time with the seat pressing the thighs in a slightly forward posture.

In recent years, the work of women in the office is centered on OA machine operation, which is to operate the keyboard and mouse in front of the monitor, and most of the OA machine operation is to maintain the same posture for a long time in front of the monitor, so it can be said that the swelling of the calf The problem has cropped up significantly in offices in recent years.

As mentioned above, observing the relationship between women and chairs, it cannot be said that existing chairs must be a suitable way/institution for women. However, in the past, it can be said that the idea of a chair with functions that women can easily use from the psychological and physical aspects has basically never existed.

The present invention is made to improve such current situation, and therefore, an object of the present invention is to provide a chair suitable for women which partially follows the idea of the above-mentioned Patent Document 1.

Solution to the problem

The chair of the present invention, as a basic structure, has: a base mounted on the legs; a seat supported by the base; a backrest on which a person who sits can lean; The member is supported by the base body and is capable of at least backward tilting against the spring means.

In addition, the above-mentioned backrest has a soft back shell that supports the body pressure of the person behind the seat, and the above-mentioned back shell is largely curved in a forward convex shape when viewed from a vertical side in a state where the back support member and the seat are not tilted backward. , the waist of the person behind the seat can be supported intensively, if the back support and the seat are tilted backward, they will be stretched and deformed in a state close to flat seen from the vertical side. This is the first feature.

In addition, the above-mentioned back shell is only installed on the back support member in such a way that the upper part cannot be separated from the front and back, so that it can be stretched and deformed. Auxiliary framework. This is the second feature. In addition, the back support of the present invention means a member on which a backrest is mounted, and does not mean a rear portion of a chair constituting a seat.

According to the present invention, the person who sits with the upper body upright touches the forward convex part of the backrest with the waist (lumbar spine), thereby keeping the center of gravity of the upper body directly above the pelvis, and maintaining the correct posture of stretching the back pleasantly. Specifically, the lumbar spine of the person seated is pressed against the forward convex part of the backrest, so that the upper body of the person seated becomes a posture with the chest raised and the back is raised. As a result, the head is easy to lift. It can be used continuously for a long time under the graceful posture, so it is especially suitable for women.

In addition, in the rocking state, the backrest is stretched and deformed to a nearly flat state (it may eventually become flat or slowly bend) when viewed from the vertical side, so there is no sense of resistance to the waist, and the waist and back Comfortable rocking position that is equally supported. This aspect is also suitable for women.

(1). Modification 1 of the present invention

The present invention has various modifications. In the first modified example, the auxiliary frame is set to be inclined backward to a greater degree than the back support member, and the lower part of the auxiliary frame and the back shell (that is, the part below the apex of the forward convex curved part) part) is connected in a state of being relatively movable in the vertical direction and inseparable in the front-rear direction, and the auxiliary frame tilts backward to a greater extent than the back support, so that the above-mentioned back shell is stretched and deformed.

(2). Modification 2 of the present invention

In the second modified example, the above-mentioned seat and the back support are fixed to each other in a manner of integrally tilting backward and moving backward, and the tilting fulcrum of the seat and the back support is located at the front of the base body. On the other hand, the above-mentioned auxiliary frame is connected to the base body. The rear part and the back support part of the seat and the back support part make the connecting part of the auxiliary frame to the base body behind the tilting fulcrum of the seat and the back support part, so that the auxiliary frame is tilted backward to a greater degree than the back support part.

(3). Modification 3 of the present invention

In the third modified example, the above-mentioned back supporting member has a horizontal portion extending below the seat to the vicinity of the front portion of the base body, and the supporting shaft provided at the front portion of the horizontal portion is connected to the base body so that it can tilt back and move backward. The long horizontal bearing portion on the base body is seated and fixed to the horizontal portion of the back support, and the auxiliary frame is connected to the rear portion of the base body so as to be tilted backward.

Like the chair of the present invention, the back support member and the seat are linked and the chair that tilts backward must be that if only the seat is taken, the seat and the back support member do not recline, and the back support member (or backrest) and the seat start when the person leans on the backrest Backward movement (or back and forth). Also, in synchronous chairs, as a device for connecting the seat to the base body in a reclining and backward movable manner, a support shaft is installed on the seat (or a metal part of the fixed seat) in most cases, and the support shaft is slidably embedded in the base body. Among the long holes opened in the base, in general synchro-type chairs, the long holes of the base are formed in a reclining posture when viewed from the side, so the seat as a whole moves backward while descending.

However, in this conventional configuration, the shaft slides arbitrarily in the long hole of the base body due to seating, so the strength of the spring supporting the shaft must be increased. Then, the resistance to swinging becomes large, which is problematic. On the other hand, according to the third modified example of the present application, the bearing part where the support shaft is embedded is horizontal, so the load caused by seating does not act in such a way that the support shaft slides, and the auxiliary frame is connected to the rear of the base body. Therefore, the load caused by sitting does not act in such a way that the auxiliary frame is tilted backward, and the two are combined to prevent the seat and the back support from tilting backward due to seating even if a weak spring is used. Therefore, it is possible to prevent the seat from receding or sinking due to seating while ensuring the ease of rocking. In general, women weigh less than men, so springs that resist swaying are preferably weaker than those used by men. The third modified example of the present application is considered as a chair for women.

(4). Modification 4 of the present invention

In the fourth modified example, the auxiliary frame is provided with a support body that supports the apex of the forwardly convex curved portion of the back shell from the back side. Since the supporting body is provided on the auxiliary frame, even if the back shell is made of soft raw materials, it will not be deformed by body pressure, and the waist of a person can be well supported. If the support body is formed in a roll shape, the relative movement between the auxiliary frame and the back shell becomes smooth, and as a result, the back shell is reliably deformed with the tilting of the back support. Therefore, it is preferable to form the support in a roll shape.

The present invention also has modifications related to the seat. In the fifth modified example, the above-mentioned seat is divided into a seat front part and a seat rear part through a curved part extending in the left-right direction, and the seat front part can be tilted forward centering on the above-mentioned curved part. The size is set to be larger than 1/4 and smaller than 1/2 of the front and rear width dimensions of the entire seat, and the front part of the seat is supported by a member arranged below the seat so that it can be moved step by step by rotating the lever. Or change the posture as seen from the side steplessly.

(5). Modifications 5 and 6 of the present invention

As mentioned above, the calf edema problem of office women is serious. However, if the structure of the fifth modification is adopted, the front part of the seat can be tilted forward to eliminate the pressure on the thigh, and the calf swelling can be eliminated or significantly suppressed. Swelling of the legs. It is particularly important here that the front-rear width dimension of the front portion of the seat is larger than 1/4 and smaller than 1/2 of the front-rear width dimension of the entire seat. With this size, the pelvis can effectively suppress the compression of the thighs while maintaining a stable state at the back of the seat.

In the sixth modified example of the present application, the front end portion of the seat is collapsed in a forward concave shape as seen from a plan view. In this way, if the front end of the seat collapses into a forward concave shape when viewed from above, the person seated will be guided to bring the knees close to the center line of the seat, and as a result, it is easy to maintain the posture of folding the knees. This is in consideration of the way women like to sit with their knees tucked together.

Also, in order to support the waist of the person correctly by the forward convex portion of the backrest, it is preferable to sit down as deeply as possible, but since sitting down very deeply, it is uncomfortable for the legs to touch the front end of the seat. Women often take the posture of stretching their legs under the seat, so the bend of the legs is particularly easy to touch the front end of the seat. However, according to the sixth modified example of the present application, the front end portion of the seat is collapsed in plan view, so that it is possible to sit down deeply while preventing the legs from touching the front end of the seat. This sixth development invention is also considered as a chair suitable for women.

Description of drawings

[ Fig. 1 ] 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 top view of the chair, FIG. 2B is a top sectional view viewed from IIA-IIA of FIG. 1A, and FIG. 2C is a rear view of the chair.

[ Fig. 3] Fig. 3A is a vertical side view of a chair, and Fig. 3B is a vertical side view of a seat and a backrest.

[ Fig. 4 ] It is a plan view in a state where a seat is omitted.

[FIG. 5] It is a perspective view of the member which comprises a rocking mechanism.

[ Fig. 6 ] It is an isolated perspective view of a base body and a lower frame member.

[ Fig. 7 ] is a sectional view seen from VII-VII in Fig. 4 .

[ Fig. 8 ] is a sectional view seen from VIII-VIII in Fig. 4 .

[ Fig. 9 ] is an isolated perspective view of the shell in the seat.

[ Fig. 10 ] is a schematic perspective view of the outer shell.

[ Fig. 11 ] It is an isolated perspective view of parts constituting the back.

[FIG. 12] FIG. 12A is a partially broken front view of the backrest, FIG. 12B is an isolated cross-sectional view viewed from BB of FIG. 12A in a state where the cushion is omitted, and FIG. 12C is a view from FIG. 12A in a state where the cushion is omitted. The cross-sectional view seen from C-C.

[ Fig. 13 ] It is an isolated perspective view of parts constituting the back.

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

[ Fig. 15 ] is a partial longitudinal side view of the back.

[FIG. 16] FIG. 16A is a conceptual diagram for explaining the dynamics of the backrest and the seat, and FIG. 16B is a conceptual diagram showing the health care waist support function.

[FIG. 17] It is an isolated perspective view which shows the support mechanism part of a front part of a seat.

[FIG. 18] It is a top view which shows the support mechanism part of a front part of a seat.

[ Fig. 19 ] is a cross-sectional view viewed from XIX-XIX in Fig. 18 .

[FIG. 20] is a sectional view viewed from XX-XX in FIG. 18.

Symbol Description

1 leg

2 substrate

3 seats

3a seat front

3b seat rear

4 back shell

4 back

Front inner shell for 9 seats

10 seat rear inner shell

12 Coupling pins

19 back support

20 tubes making up the back support

20a horizontal part

20b Back brace

22 1st pivot

26 lower bearing part

27 upper bearing part

31 spring for swing

34 Front lever for tilting the front of the seat

35 Bearing part for tiltably supporting the front part of the seat

36 cam parts

40 Auxiliary frame

42 2nd fulcrum

49 3rd fulcrum

54 Press the support of the dorsal shell from the rear

56 guide pin

Detailed ways

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

(1). Summary of the chair

First, an outline of a chair will be described with reference to FIGS. 1 to 3 . The chair includes: legs 1 ; a base body 2 attached to the upper ends of the legs 1 ; a seat 3 disposed above it; and a backrest 4 disposed behind the seat 3 . The leg 1 includes a leg post 5 made of an air cylinder and legs 6 radially extending from the leg post 5 , and a caster 7 is provided at the tip of each leg 6 . The locking of the leg post 5 is released by operating a lever 8 (see FIG. 1A ) provided on the base body 2 .

As shown in Fig. 3A and B, the seat 3 has resin front and rear seat inner thin shells (seat boards) 9, 10 and a cushion body 11 continuously extended on them. Seat rear portion 3b and seat front portion 3a that can tilt forward. The details will be described later, the front inner shell 9 and the rear inner shell 10 are connected by left and right laterally long connecting pins 12, and the seat front portion 3a can be tilted forward around the connecting pins 12.

The backrest 4 is a structure in which a cushion 4b is laid on the front of a synthetic resin back shell 4a, and behind the back shell 4a, a back cover 13 extending to the substantially full height of the back shell 4a is arranged (the back cover 13 is fixed Back support member 19 described later). The backrest 4 includes side guards 4' protruding from the left and right sides so as to surround the waist of the person seated behind. The main reason for setting the side protection 4' is to improve the posture stability of the seated person and block it when the seated person wears low-waisted pants and exposes the psoas, making it invisible from the outside.

The space between the back cover 13 and the base body 2 is blocked by the tail cover 14, and the front cover 15 is installed in the place ahead of the base body 2, and on the left and right sides of the front cover 15, exposed is used to carry out the tilting operation to the seat front portion 3a. The handle 16 (details are described later) of front bar. In addition, the front cover 15 is mounted on the front inner shell 9 of the seat 3 . Reference numeral 17 shown in FIGS. 1 and 2 is a lever 4 for switching the backrest between a reclinable state and a reclinable state.

(2). Seat and its supporting mechanism

Next, the seat 3 and its supporting mechanism will be described with reference to FIGS. 4 to 10 . The base body 2 is shaped like a bracket opening upward, and a back support 19 on which the seat 3 and the backrest 4 are attached is connected to the base body 2 as shown in FIG. 4 , for example. The back support 19 includes two left and right pipes 20 as main components. The pipe 20 includes a horizontal portion 20a extending in the front-back direction located below the seat 3, and a back support 20b raised upward from the rear end of the horizontal portion 20a.

A front bracket 21 of an upwardly open groove shape is fixed by welding to the front ends of the left and right pipes 20 constituting the back support 19 as viewed from the front. In addition, the left and right horizontally long first support shafts (also referred to as sliding shafts) 22 are fixed to the left and right front brackets 21 by welding, and the horizontal portions 20a of the left and right pipes 20 are connected by the first connecting part body 23. And the second connecting body 24 is connected into one body. The first supporting shaft 22 is disposed below the horizontal portion 20 a of the pipe 20 .

As shown in Fig. 3, the outer shell (seat plate) 25 made of resin is disposed under the rear inner shell 10, and the rear inner shell 10 is detachably fixed to the outer shell 25, and the outer shell 25 is fixed by screws. etc. are fixed to the first coupling body 23 of the back support member 19 .

As shown in FIG. 9 , the front inner shell 9 is approximately in the form of a flat plate. On the other hand, the rear inner shell 10 is gently curved upward in a concave shape when viewed from the front, and is also gently curved in an upward concave shape when viewed in longitudinal section. Furthermore, the front and rear inner shells 9, 10 are bendably connected by inserting connecting pins 12 into the left and right pairs of cylindrical bearings 9a, 10a and semicircular bearings 9b, 10b. The coupling pin 12 is located slightly behind the first supporting shaft 22 (in other words, the first supporting shaft 22 is located in front of the bending point of the seat front portion 3a).

In addition, in this embodiment, after connecting the front and rear inner shells 9 and 10, the cushion 11 is integrally formed by insert molding, but the cushion 11 may be manufactured and attached separately. The outer shell 25 is arranged directly below the rear inner shell 10, and the rear inner shell 10 is locked by fitting the claw-shaped engagement portion 25a of the outer shell 25 with the hole-shaped engagement portion 10c of the rear inner shell 10. Installed on the outer shell 25.

It can be understood from Fig. 4, 7, 8 that the first supporting shaft 22 of the back support member 19 is clamped by the lower bearing part 26 and the upper bearing part 27 overlapping up and down, and the pressing part 28 overlaps the upper bearing part 27, these three The ones are fastened on the base body 2 by screws (not shown) in a mutually overlapping state.

For example, as shown in FIG. 5 and FIG. 6, on the lower bearing member 26, four engaging holes 29, front, rear, left, and right, pass through up and down. body 2a, the lower bearing component 26 is nested on the protruding body 2a to keep the lower bearing component 26 incapable of moving in the horizontal direction. The pressing member 28 is fastened to the protrusion 2a by screws.

Formed on the base 2 is a central projection 2b that contacts the rear end of the lower bearing member 26, a hole 2c into which the leg post 5 is fitted, a protruding portion 2d for attaching an armrest (not shown), and the like. In addition, the base body 2, the upper and lower bearing members 26, 27 are die-cast products such as aluminum, and the pressing member 28 is a sheet metal product, but the raw materials and processing methods of these parts can be selected arbitrarily.

For example, as can be understood from FIG. 8 , the upper and lower bearing members 26 , 27 are formed with long grooves 30 allowing the first spindle 22 to slide back and forth. The upper and lower long grooves 30 overlap each other to form long holes. A spring (compression coil spring) 31 is arranged between the upper and lower bearing members 26 , 27 , and a rear wall 32 supporting the spring 31 from behind is formed at the rear end of the lower bearing member 26 . On the other hand, the front spring frame 33 supporting the spring 31 from the front overlaps the first spindle 22 of the back support 19 .

Therefore, the back support 19 (and the seat 3 and the backrest 4 ) can move backward against the spring 31 and can tilt backward around the first pivot 22 . The long grooves (long holes) 30 of the upper and lower bearing members 26, 27 extend in the horizontal direction. Therefore, even if the spring force of the spring 31 is not too large, the seat 3 will not tilt backward if only a person sits on the seat 3 .

In addition, the first support shaft 22 can be installed directly on the base body 2 without using the upper and lower shaft bearing parts 26, 27. In addition, the first support shaft 22 can also be manufactured separately from the back support member 19, and the first support shaft 22 can be installed separately. 22 is embedded in the long hole formed on the substrate 2.

As shown in FIG. 4 , bearing members 35 for rotatably holding the front rods are attached to the front ends of the left and right front brackets 21 , and the cam members 36 are supported by the bearing members 35 . The details of this point will be described later.

(3). Backrest and swing structure

Next, the backrest 4 and the rocking structure will be described with reference to FIG. 3 and FIGS. 11 to 15 . As mentioned above, the backrest 4 is provided with the back shell 4a made of resin, and the cushion 4b laid on the front surface (a bag-like cloth is also laid). As shown in FIG. 12A, many horizontally long micro-slits 38 are formed on the back shell 4a. Due to the existence of the group of micro-slits 38, the shape of the back shell 4a viewed from the longitudinal side can be easily changed. of softness.

As shown in Fig. 11 and Fig. 14A and B, the upper ends of the left and right back struts 20b are connected by an upper connecting body 39 with a cross-section opening to the rear. Specifically, as shown in FIG. 12B , an engaging portion 4 c is formed on the upper portion of the back shell 4 a , and the engaging portion 4 c is fitted into the upper coupling body 39 .

As shown in Figure 3A and Figure 13, as a part of the rocking mechanism, an auxiliary frame 40 (auxiliary frame can also be called a rear frame or a connecting rod) that is roughly L-shaped from the side is configured with two pipes on the left and right as main components. ). The left and right horizontally long second support shafts 42 are integrally fixed to the front ends of the left and right pipes constituting the sub frame 40 via the bracket plate 41 .

As shown in FIG. 3A, the above-mentioned second support shaft 42 is sandwiched in a rotatable state at the rear of the base body 2 by two upper and lower bearings 43 and 44. Substrate 2. Therefore, the auxiliary frame 40 can tilt around the third support shaft 42 . In addition, the auxiliary frame 40 may also be connected to the base body 2 by pins. Bearings 43 and 44 in Fig. 3 should have cross-section display originally, but no cross-section display (hatching) is given because of complexity. Also, only the upper bearing member 43 is shown in FIG. 13 .

For example, as shown in FIG. 13, the 3rd coupling body 46 made of metal plate is integrally fixed to the bottom of the left and right pipes constituting the auxiliary frame 40, and the 4th coupling body 47 made of metal plate is integrally fixed to the upper ends of the left and right pipes. . The third coupling body 46 includes a front groove 46a and an up-and-down vane 46b , while a third support shaft 49 is integrally fixed to the lower portion of the left and right back pillars 20b via a bracket member 48 .

And, as shown in FIG. 15 , the third support shaft 49 is rotatably sandwiched by the bearing bodies 50 and 51 divided into upper and lower parts, and the front and rear bearings 50 and 51 are fixed to the third joint by pressing members 52 overlapping from the front. Body 46. Accordingly, the back support 19 (back stay 20 b ) 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 coupling body 46, and the pressing member 52 is fixed to the vane 46b of the third coupling body 46 by screws.

For example, as shown in Figure 13, a pair of left and right bearing pieces 47a extending upwards are integrally formed on the 4th connecting body 47 on the auxiliary frame 40, and the pins 52 pass through the left and right bearing pieces 47a, and the roller-shaped (or roll-shaped) support body 54 is rotatably sleeved on the pin 52, and the supporting body 54 is in contact with the back of the back shell 4a. The support bodies 54 are separated on the left and right, and the portions of the left and right support bodies 54 close to the longitudinal center of the backrest 4 are in the shape of a small-diameter tapered frustum (the central part becomes thinner as a whole).

The part of the back shell 4a that is in contact with the back of the seated person is bent forward convexly as viewed from the side in such a manner that the part in contact with the support body 54 is located at the front. Also, as shown in FIG. 16B, the forward apex portion 4a' of the back shell 4a is approximately the same height as the third lumbar vertebra Y3 of the seated person.

As shown in FIG. 3A, in the back surface of the back shell 4a, the portion between the third coupling body 46 and the fourth coupling body 47 of the auxiliary frame 40 is integrally formed by a box-shaped bracket portion 54 protruding backward. A guide pin 56 that is horizontally long is formed (the guide pin 56 may be a separate member from the back shell 4a).

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 is fixed to the third coupling body 46 and the fourth coupling body 47 of the auxiliary frame 40 by screws. The guide body 57 has a guide groove 57a which is long up and down and the lower part is opened forward, and the guide pin 56 is embedded in the guide groove 57a, so that the back shell 4a cannot be disengaged from the auxiliary frame 40 forward and can be held in a relative movement up and down ( snap tight). In addition, the lower portion of the guide groove 57a is opened forward to allow the guide pin 56 to be fitted and disengaged from the front side.

13 and 14A, the auxiliary frame 40 is covered from the front by the auxiliary cover 58, and as shown in FIG. The front cover 58 has a window hole 59a for exposing approximately the upper half of the auxiliary cover 59 . The rear cover 13 is provided with claws for mounting it, however, the illustration is omitted in FIG. 9 . As shown in FIG. 14A , a hanger 60 can be installed on the upper connecting body 39 of the back support member 19 .

As can be understood from Fig. 3, the auxiliary frame 40 is installed on the base body 2 at a position close to the rear end of the seat 3. Therefore, the rotation fulcrum of the auxiliary frame 40 corresponds to the central point where the load acts when the person sits (the position pointed by the black arrow in Fig. 3A) Deviates backwards. Therefore, in the state where the person sits without relying on the backrest 4, the back support member 19 becomes a state supported from the rear by the auxiliary frame 40, thereby preventing the first pivot 22 from moving backward just by sitting on the person. Condition.

(4).Health care waist function/action of seat and backrest

Next, the operation of the backrest 4 and the operation of the seat 3 and the backrest 4 will be described. In the non-swing state, as shown in FIG. 16B , the backrest 4 is greatly curved into a forward convex shape when viewed from the vertical side. Therefore, the lumbar vertebra Y (especially the third lumbar vertebra Y3 ) of the person seated is firmly positioned from behind. Being supported, the stability of the pelvis and spine of the seated person is high. As a result, a person can continue to sit for a long time without fatigue in a straight-back posture.

Also, the forward apex portion 4a' in the backrest 4 is supported from behind by the support body 54, so the forward apex portion 4a' of the backrest 4 does not collapse or become less bent due to a person's body pressure. Therefore, the health-care waist protection function can be well maintained.

Next, the operation of the seat 3 and the backrest 4 will be described. In this embodiment, the seat 3 and the backrest 4 are mounted on the back support member 19, so the seat 3 and the backrest 4 are integrated and recline and move backward, and the degree of reclining of the back support member 19 and the degree of reclining of the seat 3 The degree is consistent.

And, the auxiliary frame 40 and the back support 20b (back support 19) are connected, so the auxiliary frame 40 is also tilted backward in conjunction with the reclining of the back support 20b. Since the fulcrum is located at the rear, the subframe 40 tilts backward at a larger angle than the back brace 20b. Also, the back support 19 moves backward, so the subframe 40 tilts backward while being pushed backward, and from this, the subframe 40 tilts backward more than the back support 20b.

Therefore, the support body 54 and the back strut 20b are tilted backward together, and accordingly the support body 54 is relatively tilted backward with respect to the back strut 20b. And, the lower portion of the back shell 4a is held so that it cannot be detached back and forth with respect to the auxiliary frame 40 because the guide pin 52 is embedded in the guide member 57. Therefore, if the support body 54 moves back relative to the back support 20b, the back shell 4a is subjected to an impact. Under the effect of traction, when viewed from the longitudinal section, the shape changes from a large warp to a forward convex shape and stretches to a nearly flat shape. Therefore, in the swing state, there will be no sense of resistance to the back and waist of the person, and the person is very comfortable.

In addition, the backrest 4 is stretched and deformed while leaning back, and as a result, the backrest 4 will lean back at a larger angle than the seat 3. Therefore, when the seat 3 and the backrest 4 are installed on the vertical back support 19, the backrest 4 can be Ensuring a comfortable rocking state with sufficient recline angle.

In this embodiment, the upper and lower dimensions of the bracket portion 55 of the back shell 4a are small, so the lower portion of the back shell 4a is easily deformed, so the back shell 4a can be warped into a naturally rounded state. Therefore, the adaptability to the human waist is good.

(5). The supporting mechanism at the front of the seat

Next, the supporting mechanism of the seat front portion 3a will be described mainly with reference to FIGS. 17 to 20 . The front bracket 21 of the back support 19 forms part of the support means of the seat front 3a, the front bracket 21 having a trough-like protrusion 21a protruding forward from the horizontal portion 20a of the tube 20.

The bearing members 35 are arranged to overlap the projecting portions 21 a of the left and right front brackets 21 . The bearing member 35 includes side plates 35a located on the left and right outer sides, a support surface 35b located inside the side plates 35a, a downward convex portion 35c fitted into the groove of the water tank-shaped extension portion 14a, and a rearward convex portion inserted into the bottom of the pipe 13. 35d, the inward piece 35e protruding from the left and right inner sides and the back panel 35f contacting the front of the front bracket 14, the rearward convex portion 35d is connected to the front bracket 21 by pins 62.

Thus, 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 base end portion which is horizontal, and is inclined on the front side.

The seat front portion 3 a changes its posture as the front lever 34 is rotated. The front rod 34 includes: the left and right central shafts 34a embedded with the bearing holes 63 formed on the side plates 35a of the bearing parts 35; the central crank 34b formed by bending between the left and right central shafts 34a; The side crank 34c formed by bending; and the fishing part 34d formed by bending at the front end of the side crank 34c, and the above-mentioned handle 16 is fixed on the fishing part 34d.

The extending direction of the central crank 34b and the extending direction of the side cranks 34c deviate by approximately 90 degrees from the axial direction of the central axis 35a. The corners of the front rod 34 are slightly rounded, and the side plate 35a of the bearing member 35 is thin, so the front rod 34 can fit its central shaft 34a into the bearing hole 63 of the bearing member 35 .

As shown in FIG. 19 , the cam member 36 is fitted over the left and right end portions of the center crank 34 b of the front lever 34 from the outside. The cam member 36 has an elongated hole 36a through which the center crank 34b of the front lever 34 can slide in a direction perpendicular to its axis, is formed in a substantially flat cylindrical shape, and has one end mounted on the support surface 35a of the bearing member 35 . The cam member 36 rotates around its base end, and can change its posture from an upright posture overlapping the back plate 35f of the bearing member 35 to a forward posture (horizontal posture) overlapping the inclined portion of the support surface 35b. On the underside of the front inner shell 9 of the seat 3, a stopper protrusion 65 for maintaining the cam member 36 in an upright posture is formed.

As shown in FIG. 20 , in the front portion of the front inner shell 9 and in the left and right middle parts, there is provided an arc-shaped guide hole 66 in which the left and right middle parts of the center crank 34 b of the front rod 34 fit. The guide hole 66 is formed by forming a downwardly concave upper guide surface 67 on the front inner thin shell 9 and installing an upwardly concave lower guide body 68, and the lower guide body 68 is embedded in and installed on the front inner thin shell 9 to form in the engaging hole 69.

Rotate (rotate) the front lever 34 by the handle 16 to change the cam member 36 according to the upright posture and the forward posture, so that the seat front portion 3a becomes the normal posture and the forward posture (referring to the dotted 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 such that a plurality of forward leaning postures can be maintained by fixing the forward leaning angle in increments of 5 degrees.

Since the cam member 36 overlaps the inclined support surface 35b of the bearing member 35 in the forward leaning posture of the seat front portion 3a, the forward leaning posture of the seat front portion 3a can be maintained. In addition, the cam member 36 rides over the stopper protrusion 65 by pushing the front inner shell 9 when it is tilted.

The dimensional relationship between the seat front portion 3a and the seat rear portion 3b of the seat 3 is shown in FIG. 3B. If the front and rear width dimension of the seat 3 as a whole is set as W0, and the front and rear width dimension of the seat front portion 3a is set as W1, then there are (1/4 W0<W1<(1/2 W0), and W1 is according to the actual size Preferably the degree of 200mm. In addition, the coupling portion (as the axis of the coupling pin 12 of the bending center) is preferably positioned at the front of the most collapsed part 3b ' of the seat rear portion 3b for 90-110mm. The seat rear portion 3b The most concave part 3b' of the seat 3 is located at the rear than the front and rear central position 3' of the whole seat 3.

(6).Others

Embodiments of the present invention are not limited to the above, and may be embodied in other various forms. For example, the form of each component such as a base body, a seat, a back support member, an auxiliary frame, and a backrest may be any form as long as the functions thereof are maintained. For example, both the back support member and the auxiliary frame can be formed products such as sheet metal products or die-casting.

It is also possible that the horizontal portion located below the seat in the back support member is a die-cast product or a sheet metal product, and the back support is made of a pipe. Also have, the present invention also can be applicable to the chair that only seat and backrest are linked and then tilted.

Claims (7)

1. a chair possesses: be installed in the matrix on the leg; Seat by above-mentioned matrix support; The seat after the people can by backrest; And the back of the body support member that above-mentioned backrest has been installed, above-mentioned seat and back of the body support member are supported by matrix, and can revolt spring assembly and fascinate at least,

Above-mentioned backrest possesses the back shell of softness of the body pressure that is supporting the people behind the seat, above-mentioned back shell is under the state of back of the body support member and not hypsokinesis of seat, bend to the convex forward of looking from vertical disconnected side greatly, the waist of the people behind the seat is being supported in the energy concentrated area, if back of the body support member and seat hypsokinesis, then by looking from vertical disconnected side and extensional deformation near flat state

Wherein, above-mentioned back shell be top can not before and after be installed on back of the body support member with breaking away from, thereby extensible distortion, be linked with on the above-mentioned back of the body support member with this back of the body support member after fascinate to link and then fascinate, thereby make the auxiliary frame of back shell extensional deformation.

2. chair according to claim 1, wherein, above-mentioned auxiliary frame is set for than back of the body support member big degree hypsokinesis, the state that the bottom of above-mentioned auxiliary frame and back shell is coupled at above-below direction and can relatively moves, can not break away from fore-and-aft direction, auxiliary frame is with than fascinating after the big degree of back of the body support member, thereby makes above-mentioned back shell extensional deformation.

3. chair according to claim 2, wherein, above-mentioned seat and back of the body support member are by fascinating after integratedly and to retreat mobile mode fastened to each other, the fulcrum that fascinates of seat and back of the body support member is positioned at the front portion of matrix, on the other hand, above-mentioned auxiliary frame is linked in the rear portion and the back of the body support member of matrix, makes auxiliary frame be positioned at the fulcrum that fascinates than seat and back of the body support member by the rear to the connection position of matrix, thereby makes auxiliary frame with than the big degree hypsokinesis of back of the body support member.

4. chair according to claim 3, wherein, above-mentioned back of the body support member possesses near the anterior horizontal portion that present below extends to matrix, be arranged on above-mentioned horizontal portion the front portion fulcrum can after fascinate and retreat and be linked in the long horizontal bearing portion in the front and back that are arranged on the matrix movably, the horizontal portion that seat is fixed in above-mentioned back of the body support member, and, but above-mentioned auxiliary frame hypsokinesis be linked in the rear portion of matrix.

5. chair according to claim 1, wherein, the supporter that supports from dorsal part in the apex that is provided with on the above-mentioned auxiliary frame the bend of the convex forward on the shell of back.

6. chair according to claim 1, wherein, above-mentioned seat folder is divided into the anterior and seat rear portion of seat every the bend that extends at left and right directions, the seat front portion can be to lean forward in the center with above-mentioned bend, the anterior front and back width dimensions of above-mentioned seat be made as than the front and back width dimensions of seat integral body 1/4 big, than its 1/2 little size, and the anterior parts by the present below of configuration of above-mentioned seat support, so as by the rotating operation of bar stage ground or have stage ground and change the posture of looking from the side.

7. chair according to claim 6, wherein, the leading section of seat collapses to overlooks the concavity of looking forward.

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