JP7598640B2 - Chair with lumbar support - Google Patents

Description

The present invention relates to a chair equipped with a vertically adjustable lumbar support that is attached to an upholstered back frame.

In recent years, breathable, lightweight, well-designed chairs with mesh fabrics on the backrest and seat are being used in offices and homes. Upholstered chairs change shape according to the back pressure, so they are comfortable to sit on, but they can lead to poor posture for people who do desk work for long periods of time, and surprisingly, many people complain of fatigue.
As a result, chairs equipped with lumbar supports to support the lower back and maintain correct posture have been considered, and a variety of types have been put into practical use, including integrated types that are fixed in an appropriate position on the chair in advance, and retrofit types that can be installed when needed.
However, the necessity for lumbar support varies from user to user, and the applicants have previously developed a chair (Patent Document 1) in which a user can later attach a lumbar support to a back frame on which an upholstery is stretched.

JP 2019-83848 A

The chair with lumbar support of Patent Document 1 comprises a frame-shaped back frame, mounting members attached to both sides of the back frame, and a lumbar support suspended between the mounting members, and the mounting members have a rail portion into which the end of the lumbar support can be inserted from at least one of the above and below, and the rail portion allows the end into which the end of the lumbar support is inserted to pass in the vertical direction.
Because of this configuration, the end of the lumbar support can be inserted and moved from at least one of the upper and lower sides to be attached.

However, this lumbar support configuration is complex and has many parts, and requires tools such as a screwdriver to attach and detach it from the back frame, making it difficult for anyone using the chair to attach and detach it, and further improvements are needed.
SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a chair equipped with a simple lumbar support having a small number of parts that can be attached and detached from the back frame in an extremely short time without using tools.

In order to achieve the above object, the chair with lumbar support of the present invention is configured as follows: That is, in a chair in which a lumbar support is attached to a back frame on which upholstery is stretched so as to be adjustable in the vertical direction, the lumbar support is a flexible, band-shaped contact plate at both ends of which is horizontally attached to an adjuster via a lumbar attachment so that the plate can move up and down in stages, the adjuster has an insertion groove through which the end of the plate passes and which can move up and down, a fixed uneven portion which fits into a moving uneven portion formed in the lumbar attachment to move the plate up and down in stages, and two locking claws at the upper and lower ends which are fitted into fitting grooves formed in the back frame from the inside of the back frame so as to be movable only forward, the lumbar attachment has an engaging portion which engages the moving uneven portion and the end of the plate inserted into the insertion groove, and the upholstery is stretched over the back frame so as to be located forward of the lumbar attachment .

The chair with lumbar support of the present invention is applicable to a chair with a back frame covered with upholstery, and the configuration of the seat and legs is not particularly limited. The back frame may be attached directly to a support or may be attached via a back support.
In this specification, upholstery refers to a stretchable (elastically deformable) sheet-like material made primarily of fabric materials such as mesh fabric, plastic resins such as nylon, cloth, synthetic leather fabric, and leather.
Lumbar supports are generally designed so that they do not deform due to the body pressure of the seated person in order to maintain the seated posture correctly. However, as a result of various experiments, the inventors of the present application have found that a softer support that can flex to a certain extent provides better comfort and sufficient support.

The lumbar support is composed of a band-shaped support plate, an adjuster that fits into a fitting groove formed in the back frame, and a lumbar attachment tool that attaches the plate to the adjuster.
The degree of bending of the support plate may be such that the linear length in the longitudinal direction is shortened by about 20 to 30 mm.
The adjuster has an insertion groove through which the end of the support plate passes and which can move up and down, a fixed uneven portion which fits into a movable uneven portion formed in the lumbar attachment fixture to move it up and down in stages, and a locking claw which fits into the fitting groove formed in the back frame so as to be movable only forward.
The range of adjustment in the vertical direction is arbitrary, but 40 mm is sufficient.
The lumbar attachment has a movable projection and recess that fits into the fixed projection and recess of the adjuster, and is fastened to the end of the contact plate.

In a lumbar support constructed and assembled in this manner, the lumbar attachment fixture will not move inward (in the direction in which the support plate shrinks), but it will move outward, and this must be prevented.
This can be achieved by attaching a stopper to the contact plate either fixedly or detachably. It is preferable to adopt the structure as described above.
In this method, three sides of the end of the contact plate are cut out and bent, and when the contact plate is inserted into the insertion groove, it is pushed in to make it flat, and when the contact plate is pulled back out of the insertion groove, it automatically rises up to form a stopper.

When installing the lumbar support, the adjuster is fitted into one of the fitting grooves on the back frame and pushed in, causing the locking claws to bend and fit into the fitting groove. Then, when installing the other adjuster, the center of the contact plate is bent outward from the upholstery to shorten the linear length of the contact plate, and it is then pushed into the other fitting groove to fit in.

Once the locking claws are engaged, they cannot move in any direction other than forward (towards the upholstery). Because the upholstery is tensioned, the lumbar support will not come out of the engagement groove.
To remove the lumbar support from the back frame, simply push the support plate into the upholstery until the locking claws of the adjuster are released from the fitting grooves.
In addition, when the lumbar support is not attached, the fitting groove portion of the back frame is exposed, so it is a good idea to attach a lid to cover it.

The chair with lumbar support of the present invention is attached horizontally to an adjuster via a lumbar attachment at both ends of a flexible band-shaped support plate, and the adjuster has an insertion groove through which the end of the plate can be inserted and which can move vertically, a fixed uneven portion which fits into a moving uneven portion formed in the lumbar attachment to move it up and down in stages, and a locking claw which fits into the fitting groove formed in the back frame so that it can move only forward, and the lumbar attachment has an engaging portion which locks the moving uneven portion and the end of the plate inserted into the insertion groove, so that the structure is simple and there are few parts, and no tools such as a wrench or screwdriver are required to attach it to the back frame. Moreover, it can be attached in a short time. It can also be easily removed when it is no longer needed.

The stopper that prevents the contact plate from entering the adjuster insertion groove is configured as described in claim 2 by cutting out three sides of the end of the contact plate and bending it, pushing it flat when inserting it into the adjuster insertion groove, and automatically rising up and engaging with the adjuster when pulled back, which reduces the number of parts and makes it easier to handle.

1 is a perspective view showing an embodiment in which a lumbar support of the present invention is installed on an office chair. FIG. 2 is a perspective view showing the entire lumbar support according to the first embodiment. FIG. FIG. 1A and 1B are enlarged perspective views of the adjuster of the first embodiment, in which FIG. 1A and 1B are enlarged views of the lumbar attachment of the same embodiment, in which (a) is a perspective view of the left side and (b) is a perspective view of the right side. FIG. 13 is an oblique view showing the state in the middle of assembling the lumbar support, where (a) shows the state before the end of the support plate is inserted into the insertion groove of the adjuster, (b) shows the state after insertion, and (c) shows the state after the lumbar mounting fixture has been attached. 13A and 13B are perspective views showing the state in the middle of attaching the lumbar support to the back frame, in which (a) shows the state before fitting, and (b) shows the state after fitting to the back frame.

An embodiment of a chair with a lumbar support according to the present invention will be described below with reference to an example in which the chair is applied to an office chair.
Fig. 1 is a perspective view showing the entire chair of the present invention, Fig. 2 is a perspective view showing the entire lumbar support, and Fig. 3 is a perspective view of the back frame. Fig. 4 is an exploded perspective view showing the components of the lumbar support, and Figs. 5 and 6 are enlarged views of the adjuster and lumbar attachment.

As shown in FIG. 1, this chair is a liftable and rotatable office chair having a seat 2 and a backrest mounted on a support (not shown, but located under the seat), a central leg post and five legs 3 with casters.
The backrest is made of a back frame 1 attached to a back support 5 fixed to the support body, and a fabric 6 (mesh fabric is used here) is stretched (not shown). A lumbar support 10 is detachably attached to the back frame 1 at a position 5 to 10 cm higher than the seat 2.

As shown in FIG. 2, the lumbar support 10 is composed of a belt-shaped support plate 11, adjusters 12 attached to both ends of the support plate, and a lumbar attachment 13 for connecting the support plate 11 and the adjusters 12. The material used here is synthetic resin (polypropylene).

The contact plate 11 is a thin (1-2 mm) strip, and both ends 11a are narrow and have mounting parts 11b (square holes in this case) for attaching to the adjuster 12, and stoppers 11c that are cut out and bent on three sides.

The adjuster 12 has the function of supporting the support plate 11 so that it can be moved in a step-like manner in the vertical direction and fitting it into the back frame 1, and is provided with a continuous fixed uneven portion 12a, an insertion groove 12b through which the end portion 11b of the support plate 11 is inserted, and a locking claw 12c that engages with the fitting groove portion 1a of the back frame 1.
The adjuster 12 has a right-angled wall 12d formed at a right angle when viewed from above, one surface of which is formed with the insertion groove 12b, and the other surface is formed with a gap therebetween to form the fixing uneven portion 12a.
Furthermore, the upper and lower ends of the adjuster 12 are provided with locking claws 12c that engage with the fitting groove portion 1a of the back frame 1. The locking claws 12c are formed in the fitting groove portion 1a so as to be movable only forward (toward the upholstery 6).

The lumbar attachment device 13 is composed of a locking portion 13a that locks into the attachment portion 11b of the support plate 11, and a movable uneven portion 13b that fits into the fixed uneven portion 12a of the adjuster 12.

Next, the operation of assembling the lumbar support will be described with reference to FIG.
First, hold the contact plate 11 and insert one end 11a into the insertion groove 12b of the adjuster 12. In this case, insert the end 11a while pressing down the stopper 11c of the end 11a to flatten it, so that the tip of the contact plate 11 protrudes from the adjuster 12 (see FIG. 7B).
Next, the locking portion 13 a of the lumbar attachment tool 13 is locked to the attachment portion 11 b of the contact plate 11 , and the moving concave-convex portion 13 b is fitted into the fixed concave-convex portion 12 a of the adjuster 12 .
Then, the end 11a of the contact plate 11 is pulled back from the adjuster 12 until the stopper 11c is exposed from the adjuster 12. This causes the movable uneven portion 13b to completely fit into the fixed uneven portion 12a of the adjuster 12, and the stopper 11c automatically floats up (see FIG. 7(c)). The other end of the contact plate 11 is assembled in the same manner.

There is little need to disassemble this lumbar support, but it can be easily disassembled by pushing in the stopper 11c to protrude the contact plate 11 from the adjuster 12, and then removing the lumbar attachment 13 from the contact plate 11 and the adjuster 12.

Next, the operation of attaching the lumbar support 10 thus assembled to the fitting groove portion 1a of the back frame 1 will be described with reference to FIG.
One adjuster 12 of the lumbar support 10 is fitted into the fitting groove portion 1a of the back frame 1 from inside the back frame 1a, and the locking claw 12c is pushed into the fitting groove portion 1a to fit it in place.
Subsequently, the other adjuster 12 is fitted into the fitting groove 1a of the opposing back frame 1. In this case, the contact plate 11 is bent so that the adjuster 12 is positioned inside the back frame 1, which facilitates assembly.

To remove the lumbar support 10, push the adjuster 12 forward (towards the upholstery 6) to disengage the locking claw 12c of the adjuster 12 from the fitting groove 1a, and then flex the contact plate 11 while removing it from the fitting groove 1a. The other adjuster 12 can be removed in the same manner.

1 Back frame 1a Fitting groove 2 Seat 3 Leg 5 Back support 6 Upholstery 10 Lumbar support 11 Contact plate 11a End 11b Mounting portion 11c Stopper 12 Adjuster 12a Fixed uneven portion 12b Insertion groove 12c Locking claw 12d Right-angle wall 13 Lumbar attachment 13a Locking portion 13b Moving uneven portion

Claims (2)

A chair with an upholstered back frame and a lumbar support that is adjustable in the vertical direction.
The lumbar support is a flexible band-shaped support plate with both ends horizontally attached to an adjuster via a lumbar attachment so that the plate can move up and down in stages, and the adjuster has an insertion groove through which the end of the plate passes and which can move up and down, a fixed uneven portion which fits into a moving uneven portion formed in the lumbar attachment to move the plate up and down in stages, and two locking claws at the upper and lower ends which are fitted into fitting grooves formed in the back frame from the inside of the back frame so as to be movable only forward ,
The lumber attachment includes a locking portion that locks the end of the plate inserted through the moving uneven portion and the insertion groove,
A chair equipped with a lumbar support, characterized in that an upholstery is stretched on the back frame so as to be positioned forward of the lumbar attachment . The chair with lumbar support according to claim 1, characterized in that, after the contact plate is attached to the adjuster, the end of the contact plate is bent by cutting three sides, and when the contact plate is inserted into the insertion groove, it is pushed flat and a stopper is provided to automatically lift the contact plate when the contact plate is pulled back and removed from the insertion groove, in order to prevent the contact plate from moving toward the back of the insertion groove.

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