JPH0719310Y2 - Chair lumbar support mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a lumbar support mechanism adapted to adjust a back seat contacting a waist of a seated person to a desired cushion hardness.

(Prior Art) Recently, as a vehicle chair or a medical chair (mainly for an operator), a back seat that contacts the waist is adjusted to a desired cushion hardness according to the user's preference. Chairs with lumbar support mechanisms are often used. An example of such a mechanism is disclosed in Japanese Patent Publication No. 54-42296.

(Problems to be solved by the invention) However, since the lumbar support mechanism according to the above-mentioned prior art is integrally assembled with the back seat frame and the back seat of the chair, the back cover is not used when the seat cover or the like is soiled or torn. It is not possible to replace only the seat, and it is necessary to replace the seat with the back frame or the entire chair, which increases the cost.

The present invention has been made in view of the above, in which the backsheet is detachably attached to the backsheet frame, the lumbar plate is attached to the backsheet, and the lumbar plate pushing mechanism is provided on the backsheet frame. Thus, it is possible to easily replace only the back seat, and it is possible to make compatibility between chairs having no lumbar support mechanism or chairs having different mechanisms, which is convenient.

(Means for Solving the Problems) The configuration of the present invention that achieves the above object will be described with reference to the accompanying drawings. FIG. 1 is a perspective view showing an example of a chair in which the mechanism of the present invention is adopted, FIG. 2 is a longitudinal sectional view of the main part, FIG. 3 is a perspective view of the back seat frame, and FIG. 4 is the back seat. FIG. 5 is a perspective view of the substrate, FIG. 5 is a view similar to FIG. 2 of another embodiment,
FIG. 6 is a view similar to FIG.

That is, the lumbar support mechanism for a chair according to the present invention includes a back seat frame 1 for a chair, and a back seat frame 1 for the back seat frame 1.
A backsheet 2 which is detachably covered on the front surface of the backsheet via a backsheet substrate 20, a lumbar plate 3 which is arranged on the front surface of the substrate 20 of the backsheet 2 so as to be movable back and forth, and inside the backsheet frame 1. The pushing mechanism 41 including the pushing member 41 and the operating member, which has an opening 21 in the surface area of the backsheet substrate 20 corresponding to the lumbar plate 3, and the pushing member of the pushing mechanism 4. 41 pushing part 41d
The gist of the present invention is to press the back surface of the lumbar plate 3 through the opening 21.

Further, in the present invention, the pushing member 41 includes a punch piece 41a pivotally supported by a fixed horizontal shaft in the back seat frame 1 so as to be swingable back and forth, and a tip side of the punch piece 41a to the front side. And a pressing portion 41d which is formed so as to project toward and penetrates the opening 21 of the substrate 20 and presses against the back surface of the lumbar plate 3.

A first invention is provided with a cam roller 41c axially supported on the tip side of the punch piece 41a of the pushing member 41, and the operating member is the surface of the back plate 11 inside the back plate 11 of the back seat frame 1. An operating lever 43 pivotally attached along the region, and a cam member having forwardly oriented parallel cam surfaces of at least two stages attached to the front side of the operating lever 43 and contacting the cam roller 41c.
It consists of 45 and.

On the other hand, the operating member of the second invention is a nut 47 screwed to an operating screw shaft 46 axially supported in the back plate 11 of the back seat frame 1 so as to be able to move forward and backward, and the nut 47.
And a contacting piece 48 that is attached to 47 and comes into contact with the back of the tip side of the punching piece 41a.

The back seat frame 1 is erected on one side of a seat plate seat 5 installed on the supporting leg 50, and the lumbar plate 3 is made to contact the back surface of the waist of a human body seated on the seat seat seat 5. . The back seat 2 including the lumbar plate 3 is covered with a back cushion 22. Also,
The lever button 42 and the handle 42 attached to the operation lever 43 or the operation screw shaft 46 of the operation member of the push-out mechanism 4 are usually provided on the back surface or the side portion of the back seat frame 1 so as to be operated while seated. Made possible.

(Operation) In the chair having the lumbar support mechanism having the above configuration, when the operation member is operated, the pushing member of the pushing mechanism 4 is pushed.
41 acts on the lumbar plate 3 through the opening 21, and the lumbar plate 3 projects forward of the back seat 2. Therefore, the user can appropriately operate the operation member to
The backsheet 2 can be adjusted to a desired cushion hardness.

Further, the back seat 2 is detachably attached to the back seat frame 1 by attaching the substrate 20 thereof to the back seat frame 1 so that the back seat 2 can be attached to and detached from the back seat frame 2. If it is worn out, remove only the back sheet 2 together with its substrate 20,
The pushing member 41 and the operating member can be continuously used by replacing them while being fixed in the back seat frame 1. Furthermore, the detachable mounting relationship between the back seat 2 and the back seat frame 1 can be standardized so as to be mutually compatible between the presence or absence of the extrusion mechanism 4 or different ones of the mechanism 4, As a result, the backsheet 2 can be used interchangeably between chairs, and the color, material, or appearance of the backsheet 2 can be selected and used according to the preference of the user.

(Example) Next, an example will be described.

(Example-1) The chair with the lumbar support mechanism shown in FIG.
a supporting leg 50 having a ..., a seat plate sheet 5 rotatably installed on the supporting leg 50, a back seat frame 1 erected on one side of the seat plate sheet 5, and a front surface of the frame 1. And a back sheet 2 covered with the back sheet 2.

As shown in FIGS. 2 and 3, the back seat frame 1
An operation lever 43 is pivotally attached to the inner surface of the back plate 11 of the back seat frame 1 via a pivot 44 so as to be rotatable in its parallel plane area. The lower end of the lever 43 is bent into an L shape,
The bending piece projects rearward from the arcuate groove 12 centered on the pivot axis 44 formed in the back plate 11, and the lever button 42 is fixed to the protruding portion. Further, a stepped cam member 45 is fixed to the upper end of the lever 43. On the other hand, the pushing member 41 is composed of a pair of parallel rod pieces 41a, 41a, and the rod pieces 41a, 41a are moved back and forth by a support shaft 41b extending between the side plates 13, 13 of the back seat frame 1. It is pivotally supported so that a cam roller 41c is provided on the back of the upper end of both rod parts 4
The rod parts 41a, 41 are axially supported together between 1a, 41a.
Pushing portions 41d, 41d are formed on the front side of the upper end of a. The cam roller 41c is capable of relatively rolling the cam surface of the cam member 45, and when the lever button 42 is operated left and right along the arc groove 12, the cam member 45 moves left and right with the pivot 44 as a fulcrum. The action of the cam roller 41c rolling on the cam surface causes the rod pieces 41a, 41a to swing back and forth around the support shaft 41b. As a result, the pushing portions 41d, 41d are displaced back and forth. In the illustrated example, the cam member 45 has a two-step cam surface,
41c receives the cam action of the upper three stages including the plate surface of the back plate 11. This means that the cushion hardness of the lumbar plate 3 can be varied among three types.

The backsheet 2 includes a substrate 20 mounted to cover the front surface of the backsheet frame 1 as shown in FIGS. 2 to 4. Brackets 23 are fixed to the back surface of the substrate 20, and the back seat frame 1
It is fastened and fixed to the side plates 13, 13 with bolts or the like. The back seat 2 can be attached to and detached from the back seat frame 1 by the attachment relationship via the brackets 23 ... And bolts. The substrate 20 is provided with an opening 21 so as to allow the pressing portions 41d, 41d to project.
The lumbar plate 3 is locked so as to cover the front surface of the. The lumbar plate 3 is formed by bending a metal plate and is hooked to the groove 24 formed in the substrate 20, but the mode of this locking is not limited to the illustrated example.
The front surface of the substrate 20 including the lumbar plate 3 is covered with the back cushion 22, and the back seat 2 is constituted by this.

By operating the lever button 42 as described above, the pushing portions 41d, 4d
When 1d presses the back surface of the lumbar plate 3, the lumbar plate 3 swings around the locking point as a fulcrum and the back cushion 22 is projected forward. When the lever button 42 is operated in the reverse direction, the lumbar plate 3 retracts due to the restoring elasticity of the back cushion 22 or the back pressure of the seated person.

(Embodiment 2) In the embodiment shown in FIGS. 5 and 6, the pushing member 41 bent by the metal rod is used as the horizontal shaft between the side plates 13 of the back seat frame 1. It is fixed to the supported shaft 41e,
It can swing back and forth with the support shaft 41e as a fulcrum.
The upper portion of the pushing member 41 is bent to the front side, and the back seat 2
The distal end portion of the opening 21 protrudes from the opening 21 and serves as a pressing portion 41f. In addition, the side plates 13, 13 of the back seat frame 1
An operation screw shaft 46 is rotatably supported between the support plate 14 and the back plate 11 of the back seat frame 1 which are installed between them. The rear portion of the screw shaft 46 projects from the rear plate 11, and the operation handle 42 is fixed to the rear end portion thereof. The screw shaft 46
A nut 47 is screwed onto the nut 47, and the nut 47 has an abutment piece 48 that comes into contact with the back portion of the pressing member 41.
48 is stuck.

When the operating handle 42 is twisted, the screw shaft 46 rotates, and the nut 47 is relatively screwed / retreated along the axial direction of the screw shaft 46. Screwing this nut 47
The pressing shaft 48 acts on the pushing member 41 by screwing back and forth, and the pushing member 41
41 swings back and forth around the support shaft 41e as a fulcrum. Therefore, in the case of the present embodiment, the cushion hardness by the lumbar plate 3 can be varied steplessly.

A back seat 2 similar to the one described above is detachably attached to the back seat frame 1, and the lumbar plate 3 locked to the back seat substrate 20 is pushed out and retracted by the back and forth swing of the pushing member 41. . Since other configurations are the same as those of the above-described embodiment, the same reference numerals are given in the drawings and the detailed description thereof will be omitted.

In the above embodiment, the example in which the lumbar plate 3 is locked to the back sheet substrate 20 is shown.
Those that are integrally bonded to the inner surface of are not excluded.

(Effects of the Invention) As described above, the lumbar support mechanism of the present invention includes a lumbar plate on a back seat detachably attached to a back seat frame of a chair, and an extrusion mechanism that acts on the lumber plate. Since it is equipped on the back seat frame, it can be replaced only when the back seat is dirty or torn, and the back seat frame including the extrusion mechanism and other chair components are used as they are. As a result, it is possible to renew the chair and the like at an extremely simple and low cost.

Further, by adopting such a configuration, it is possible to standardize the detachable mounting relationship of the backsheet so as to be mutually compatible between the presence or absence of the above-mentioned extrusion mechanism or those having different mechanisms. As a result, the back seats can be used interchangeably between chairs, and the color, material, or appearance of the back seats can be selected and used according to the preference of the user, which is extremely convenient.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an example of a chair to which the mechanism of the present invention is adopted, FIG. 2 is a longitudinal sectional view of the main part, and FIG. 3 is a perspective view of the back seat frame. FIG. 4 is a perspective view of the back sheet substrate, FIG. 5 is a view similar to FIG. 2 of another embodiment, and FIG. 6 is a view similar to FIG. (Explanation of symbols) 1 …… Back seat frame, 2 …… Back seat, 20
…… Substrate, 21 …… Aperture, 3 …… Lumber plate, 4
…… Extrusion mechanism, 41 …… Pushing member.

Claims (2)

[Scope of utility model registration request] 1. A back seat frame (1) for a chair, a back seat (2) detachably covered on the front surface of the back seat frame (1) via a back seat substrate (20), and the substrate. A lumbar plate (3) arranged in the front surface of an opening (21) in the surface area of (20) so as to be movable back and forth; and a pushing member (41) mounted in the back seat frame (1). Extrusion mechanism including operation member (4)
A push member (41) pivotally supported by a fixed horizontal shaft in the back seat frame (1) so as to be capable of swinging back and forth, and the push member (41a). A cam roller (41c) pivotally supported on the front side, and a front part of the punch piece (41a) projectingly formed forward so as to penetrate the opening (21) of the substrate (20). And a pressing portion (41d) that presses against the back surface of the lumbar plate (3), wherein the operating member is inside the back plate (11) of the back seat frame (1). An operation lever (43) pivotally attached along the surface area, and at least two parallel cam surfaces attached to the front side of the operation lever (43) and contacting the cam roller (41c). A chair lumbar support mechanism consisting of a forwardly oriented cam member (45). 2. A back seat frame (1) for a chair, a back seat (2) detachably provided on the front surface of the back seat frame (1) via a back seat substrate (20), and the substrate. A lumbar plate (3) arranged in the front surface of an opening (21) in the surface area of (20) so as to be movable back and forth; and a pushing member (41) mounted in the back seat frame (1). Extrusion mechanism including operation member (4)
A push member (41) pivotally supported by a fixed horizontal shaft in the back seat frame (1) so as to be capable of swinging back and forth, and the push member (41a). A pressing portion (41d) that is formed so as to project forward from the front side of the lumber plate, penetrates the opening portion (21) of the substrate (20) and presses against the back surface of the lumbar plate (3), The operating member comprises an operating screw shaft (4) axially supported in the back plate (11) of the back seat frame (1) in the front-rear direction.
6) a nut (47) screwed so as to be capable of advancing and retreating, and an abutment piece (48) attached to the nut (47) and abutting against the back of the tip side of the punch part (41a). A lumbar support mechanism for the chair.