JPH0527090Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to the structure of an elasticity adjustment device for the backrest of an office or task chair.

[Conventional technology]

There are various ways to adjust the cushion performance (strength or weakness of the resistance force supporting the load of leaning) when the user leans on the backrest of office or work chairs. For example, Japanese Patent Publication No. 63-16121 In the publication, a frame-shaped central elastic member is disposed within a box-shaped frame on the back of the seat body and/or backrest of an automobile seat, and this central elastic member is mounted between the side edges of the box-shaped frame. A rigid suspension structure is rotatably provided to connect the box-shaped frame and the central elastic member while being resiliently supported by a large number of suspension spring groups, and fixing means for fixing and releasing the rigid suspension structure in a tensioned position. It is disclosed that the elastic force of the plurality of suspension spring groups is sealed.

[The problem that the idea attempts to solve]

According to this configuration, when the fixing means is manually operated to release the fixed position of the rigid suspension structure, the suspension is created by the dual elastic forces of the central elastic member itself and the numerous groups of suspension springs surrounding it. On the other hand, if the rigid suspension structure is fixed in position, the central elastic member itself becomes the same as if it were fixed to the box-shaped frame, and the cushioning performance is achieved only by the elastic force of the central elastic member itself. All you have to do is demonstrate.

However, it is not possible to provide an arbitrary elasticity between the above two types of cushion performance, and it is necessary to adjust the cushion performance to obtain various cushion performances according to the user's preference or to adjust the elasticity according to the user's weight. The drawback was that it was not possible to automatically adjust the strength of the elasticity.

In view of this conventional drawback, the present invention makes it possible to change the stiffness of the backrest, which is the basis of the elastic performance of the backrest of a chair, to various sizes, thereby making it possible to obtain various cushion performances. They are trying to provide chairs.

[Means to solve the problem]

Therefore, the invention of the first claim of the present application is such that the backrest of the chair is formed of an elastic plate, and the backrest has a vertically long shape that can be freely curved in the distance direction with respect to the backside of the backrest. A reinforcing rib body having a bulging portion is provided, and at least one end of the right and left ends of the reinforcing rib body is attached so as to be slidable in the left and right direction of the backrest. On the other hand, the invention is characterized in that an interlocking means is provided on the back side of the backrest for driving the bulging portion of the reinforcing rib body in a distance direction with respect to the backside of the backrest. The seat body and the backrest of the chair are integrally formed by a substantially L-shaped plate when viewed from the side and have elasticity, and the rear part of the seat body is formed so that both left and right sides of the seat body are integrally connected to the lower end of the backrest when viewed from above. A free end portion is formed by cutting and molding into a substantially U-shape, and a reinforcing rib body having a vertically elongated bulge that can be freely curved in a direction toward and away from the back surface of the back support portion is disposed on the back surface of the back support portion. At least one of the right and left ends of the reinforcing rib body is attached so as to be slidable in the left and right direction of the backrest, while the free end of the reinforcing rib body and the seat body Between the department and
The structure includes interlocking means for driving the bulging portion of the reinforcing rib body in a direction away from the back surface of the backrest in response to the downward movement of the free end portion.

[Functions and effects of the invention]

In both the devices of the first claim and the second claim, the backrest is made of an elastic plate such as a synthetic resin plate or a metal plate, and a backrest is provided on the back of the backrest. The cushioning performance of this backrest is determined by the bending rigidity of both the backrest itself and the reinforcing ribs. It is determined by the size.

Therefore, if the bulge deforms away from the back surface of the backrest, the bending rigidity of the reinforcing rib body increases, and the bending rigidity of the backrest as a whole also increases, causing the cushion of the backrest to become stiffer. can be made hard,
On the other hand, when the bulging part of the reinforcing rib body is brought closer to the back surface of the backrest part, the bending rigidity of the reinforcing rib body becomes smaller, and the bending rigidity of the whole backrest part also becomes smaller, so that a soft backrest part of the cushion can be provided. become.

At least one end of the right and left ends of the reinforcing rib body is attached so as to be slidable in the left and right direction of the backrest, while the reinforcing rib body is attached to the back of the backrest. Since the interlocking means is provided to drive the bulge in the distance direction with respect to the rear surface of the backrest, the degree of bulge of the vertically long bendable bulge in the reinforcing rib body is controlled via this interlocking means, that is, the bulge. By arbitrarily adjusting the degree of separation from the rear surface of the backrest, the bending rigidity of the entire backrest can be adjusted as desired. In other words, the stiffness or softness of the cushion in the backrest can be adjusted as desired.

In the first aspect of the invention, the cushion performance can be adjusted as desired by manually operating the interlocking means.

On the other hand, in the invention of the second claim, the seat body and the backrest portion of the chair are integrally formed by an elastic plate having a substantially L-shaped cross section when viewed from the side, and both left and right sides of the rear part of the seat body are formed at the lower end of the backrest. A free end is formed by separating and molding into a substantially U-shape in plan view so as to be integrally connected with the reinforcing rib body, and between this free end and the reinforcing rib body,
The structure is provided with interlocking means for driving the bulging part of the reinforcing rib body in a direction away from the back surface of the backrest in accordance with the downward movement of the free end part,
Since the amount of downward movement of the free end increases or decreases in proportion to the weight of the person sitting on the seat, this amount of movement is determined by the interlocking means to determine the degree of curvature (bending rigidity) of the bulge of the reinforcing rib body. can be changed automatically.

That is, when a heavy (light) person sits on the seat, the bending rigidity of the backrest as a whole increases (decreases), and the cushion of the backrest also becomes harder (softer).

In this way, according to the invention of the second claim, the cushioning performance of the backrest can be automatically adjusted to the optimum according to the weight of the person sitting on the chair, which improves ergonomics. We can provide superior chairs.

〔Example〕

Next, to explain an example, FIGS. 1 to 6
The figures show the first embodiment, and the office chair 1 is
A support stand 3 is fixed to the upper end of a leg support 2 having a caster at the lower end, and the front part of the support stand 3 and the lower front part of a shell plate 4 having an L-shape in side view are pivotally supported by support pins 5. A shock absorbing spring means 6 is interposed between the support base 3 and the lower surface of the shell plate 4.

The backrest part 7 and the seat body 8 are made by integrally molding an elastic plate such as a thin synthetic resin plate into an L-shape when viewed from the side. 4, and cushion materials 9, 10 such as foamed polyurethane resin are stretched over the surfaces of the backrest 7 and the seat 8.

As is clear from FIG. 3, the left and right end portions of the seat body 8 are integrally connected to the lower end of the backrest portion 7, and the rear end of the center sandwiching the left and right connecting portions 11, 11 is approximately a planar surface. The free end portion 12 is formed by cutting and molding into a letter shape.

Reference numeral 13 denotes a reinforcing rib body disposed on the back surface of the backrest portion 7, and the reinforcing rib body 13, like the backrest portion 7, is made of an integrally curved elastic thin plate made of synthetic resin or the like. The reinforcing rib body 13, which is longitudinal in the vertical direction of the backrest part 7, has a vertically long bulging part 14 that is freely curved and has an arcuate cross section between the left and right end parts 13a, 13a of a vertically long flat plate. We are fully prepared.

This reinforcing rib body 13 is arranged on the back surface of the backrest part 7, and the right and left ends 13a, 1 of the reinforcing rib body 13 are
3a is attached to the backrest portion 7 through the elongated hole 15 and the sliding pin 16 so as to be slidable in the left-right direction.

Reference numeral 17 indicates the free end portion 12 disposed between the reinforcing rib body 13 and the free end portion 12 of the seat body 8.
An interlocking means for driving the bulging part 14 of the reinforcing rib body 13 in a direction away from the back surface of the backrest part 7 according to the downward movement of the interlocking means 1 according to the first embodiment.
Reference numeral 7 denotes a pressing cam 19 having an oval shape or the like, which is pivotally supported on the back surface of the backrest portion 7 so as to move up and down on a horizontal axis 18, and a rod-shaped or wire-shaped connection connecting the pressing cam 19 and the free end portion 12. This pressing cam 19 is brought into contact with the bulging portion 14 of the reinforcing rib body 13.

Note that the reference numeral 19a is a return spring for the pressing cam 19;
Reference numeral 21 indicates a hole formed so as not to interfere with the back surface of the backrest when the pressing cam 19 rotates downward.

With this configuration, when a human load is applied to the cushion material 9 on the seat 8, the free end 12 at the rear of the seat 8
moves downward in proportion to the body weight, and the reinforcing rib body 13
The bulging portion 14 is elastically deformed in accordance with the amount of downward movement of the free end portion 12 so as to be largely separated from the back surface of the backrest portion 7. At this time, the left and right end portions 13a, 13a of the reinforcing rib body 13 approach each other along the elongated hole 15.

As the bulging portion 14 of the vertically elongated reinforcing rib body 13 is separated from the back surface of the backrest 7, the overall moment of inertia of the backrest 7 and the reinforcing rib 13 increases, and the backrest The bending rigidity of the backrest portion 7 with the reinforcing rib body 13 increases when a leaning force is applied that curves the middle part of the backrest portion 7 in the vertical direction (Y direction) so as to be convex toward the back side (Z direction). This is similar to when the cushion in the backrest becomes stiff.

In other words, the bulge 1 in the reinforcing rib body 13
The degree of protrusion 4 is proportional to the weight of the load on the seat body 8.

In addition, since a person with a light weight will have less load to lean on the backrest part 7, as mentioned above, by leaning on the backrest part 7 which has low bending rigidity,
It gives you the feeling of sitting on a soft cushioned chair.

On the other hand, when a heavy person sits down, the cushion does not feel too soft because it is similar to leaning against the backrest 7 which has a large bending rigidity.

In this way, the strength of the cushion that resists the leaning force on the backrest is automatically adjusted in proportion to the weight of the person sitting on the seat body 8 of the chair. Regardless of the situation, a chair with optimal cushioning properties can be provided.

7 to 9 show a second embodiment, in which a connecting body 22 is connected to a free end 12 which is the rear end of a seat plate 7.
extends upward integrally or separately, and on the back side of the backrest portion 7 are a pair of left and right vertically elongated reinforcing ribs 23, 23.
A bulging portion 2 having a substantially V-shaped cross section is arranged between the left and right end portions 23a, 23a of each reinforcing rib body 23.
4 are integrally molded, and each reinforcing rib body 23,
The outer ends 23a, 23a of 23 are connected to the backrest part 7 with a pin 25, while the other inner end 23a,
A sliding pin 27 protruding from 23a is fitted into a pair of upper and lower horizontally elongated holes 26 (drilled in the backrest 7).
Constructed to be movable left and right.

The interlocking means 28 for driving the bulging portions 24, 24 of the pair of left and right reinforcing rib bodies 23, 23 to move closer and closer to the back surface of the backrest portion 7 is a pair of left and right reinforcing rib bodies 23, 23 connected by a pin 29 in an X-shape when viewed from the front. Links 30, 30 and
An engagement pin 3 is located in the middle of the pair of links 30, 30.
1 and the connecting body 22 which is attached via a horizontally elongated engagement hole 33 (drilled in the connecting body 22). The pair of links 30, 30 are biased by a spring 32 in a direction in which the distance between both ends becomes narrower, and each elongated hole 34 bored in the upper and lower ends of the pair of left and right links 30, 30 is It is configured to fit into the sliding pin 27.

With this configuration, when the rear end of the seat body 8 moves downward, the left and right links 30 are
The left and right inner end portions 23 are arranged so that the vertical angles 3 and 30 widen and the apexes of the respective bulging portions 24 and 24 of the pair of left and right reinforcing rib bodies 23 are separated from the back surface of the backrest portion 7.
a, 23a moves toward the left and right outer sides of the backrest portion 7.

In this way, the bulges 24 in the pair of reinforcing rib bodies 23 are adjusted in proportion to the weight applied to the seat body 8.
As the backrest 7 moves away from the back surface of the backrest 7, the bending rigidity of the backrest 7 in the Y direction increases, making it a so-called stiff backrest of a cushion.

Note that the interlocking means consisting of the pressing cam 19 in FIG. 3 and the pair of X-shaped links 30, 3 in FIG.
If a downward force is applied to the interlocking means consisting of 0 through the manual rotation lever 35 and wire 36 as shown in the dashed line in FIG. By increasing the bending rigidity of the shank, the cushion can be made harder, and by providing a means (such as a latch pawl) 37 for fixing the rotation angle of the rotation lever 35, the degree of hardness or softness of the cushion can be finely adjusted. It can be adjusted.

[Brief explanation of drawings]

Fig. 1 to Fig. 6 show the first embodiment, Fig. 1 is a perspective view of the chair, Fig. 2 is a cross-sectional view from the - side of Fig. 1, and Fig. 3 is a view of the seat and backrest. FIG. 4 is a cross-sectional view of FIG. 2, FIG. 5 is an enlarged cross-sectional view of FIG. 3, FIG. 6 is a cross-sectional view of FIG. 5, and FIG. 7 is a cross-sectional view of FIG. A perspective view, FIG. 8 is a back view of the backrest, and FIG. 9 is a cross-sectional view taken from the side in FIG. 7. 1...Chair, 2...Leg support, 3...Support stand, 4
... Shell plate, 5 ... Support pin, 6 ... Spring means, 7 ... Backrest, 8 ... Seat body, 9, 10 ... Cushion material, 11, 11 ... Connection part, 12 ... Free End portion, 13, 23...Reinforcement rib body, 14, 24
...Bulging portion, 17, 28... Interlocking means, 19...
Pressing cam, 20, 22... Connecting body, 30, 30...
... Link, 32 ... Spring, 35 ... Rotating lever,
37...Fixing means.

Claims (1)

[Claims for Utility Model Registration] (1) The backrest of the chair is formed of an elastic plate, and the back of the back has a vertically long shape that can be freely curved in the distance direction with respect to the back of the back. A reinforcing rib body having a bulging portion is provided, and at least one end of the right and left ends of the reinforcing rib body is attached so as to be slidable in the left and right direction of the backrest. A device for adjusting the elasticity of a backrest in a chair, characterized in that an interlocking means is provided on the backside of the backrest for driving the bulging portion of the reinforcing rib body in a distance direction relative to the backside of the backrest. (2) The seat body and backrest of the chair are integrally formed with an elastic board that is approximately L-shaped when viewed from the side, and the rear part of the seat body is integrally connected on both left and right sides with the lower end of the backrest. A reinforcing rib is formed by cutting and molding it into a substantially U-shape when viewed from above to form a free end, and the backrest has a reinforcing rib on the back surface thereof, which is provided with a vertically elongated bulge that can be freely curved in the distance direction with respect to the back surface of the backrest. The reinforcing rib body and the seat body are attached so that at least one of the right and left ends of the reinforcing rib body can be slid in the left and right direction of the backrest. A backrest of a chair characterized in that interlocking means is provided between the free end and the free end to drive the bulging part of the reinforcing rib body in a direction away from the back surface of the backrest in accordance with the downward movement of the free end. Elasticity adjustment device for the butt.