JP4008567B2 - Chair backrest height adjustment device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a chair backrest height adjustment device.
[0002]
[Prior art]
Conventionally, a known example of a chair height adjusting device is disclosed in Japanese Utility Model Laid-Open No. 54-4711. This adjustment device has an oval backrest attached to a backrest that can be moved up and down, a long guide hole is formed in the backrest and upside down, a tightening bolt is inserted into this guide hole, and a backrest support plate The backrest 杆 is pressed between the tightening bolt and the backrest support plate, and the height of the backrest is adjusted and fixed within the range of the guide hole of the backrest heel. ing.
[0003]
[Problems to be solved by the invention]
However, in the case of the chair described in the above publication, since the height of the backrest is adjusted using the concentrated tightening force of the tightening bolt, the fixed backrest rotates around the tightening bolt. As well as being easy, rattling and loosening are likely to occur.
In addition, if the backrest is inadvertently lowered to the lowest limit, the tightening bolt will come into contact with the receiving part and an impact will be applied, and the tightening bolt may be deformed or damaged, resulting in poor durability. There's a problem.
[0004]
Further, the backrest wrinkles are easily crushed by the tightening force of the tightening bolts, causing looseness and backlash. Therefore, the backrest cannot be securely fixed to the backrest support plate.
[0005]
The present invention has been made in view of the above-mentioned problems of the prior art, and can be securely fixed without backlash or looseness of the backrest, and is excellent in design and long. It is an object of the present invention to provide a chair backrest height adjustment device that is durable against period use.
[0006]
[Means for Solving the Problems]
The present invention solves the above problems as follows.
(1) A long elongate hole is formed in the backrest saddle attached to the seat plate of the chair, and a cylindrical portion is provided on the shell constituting the backrest of the chair to slide the backrest up and down. the insert the threaded portion of the handle threaded into the elongated hole of the backrest rod, the clamping force of the cylindrical portion caused by causing screwed into the internal thread of the front Symbol cylindrical portion, said backrest rod and挾圧fixed, The height of the backrest is adjusted, and the cylindrical portion is provided with a vertical rear recessed portion having a U-shape in a plan view in the center portion of the vertical substrate, and a screw is provided at the front opening of the rear recessed portion. The metal fitting is formed by welding so as to close the opening .
[0007]
(2) In the above item (1), a notch is provided around the internal thread of the cylindrical portion, and the vicinity of the internal thread of the cylindrical portion can be bent in the front-rear direction.
[0008]
(3) In the above item (1) or (2), the cylindrical portion is disposed between the outer shell and the inner shell.
[0009]
(4) In any one of the above items (1) to (3), when a locking piece is provided on the upper portion of the tubular portion and the backrest is lowered to the lowest limit, the upper end of the backrest and the locking piece To make contact.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of a chair height adjusting device according to the present invention will be described with reference to the accompanying drawings.
[0011]
FIG. 1 is an exploded perspective view of a chair backrest height adjusting device according to the present embodiment as viewed from the front upper side, and FIG. 2 is a cross-sectional view of the chair backrest of FIG.
[0012]
As shown in FIG. 1, the height adjusting device of the present embodiment includes a backrest (10), a backrest saddle (12), a seat plate (14), and the like, and the backrest (10) has a configuration to be described later. Thus, it can move up and down along the backrest ridge (12) fixed to the seat plate (14). A cushion member or the like (not shown) is attached to the seat plate (14) to constitute a seat portion of the chair.
[0013]
The backrest (10) comprises a skin material (18), a cushion material (20), an inner shell (22), an outer shell (24), a slide fitting (26), a screw fitting (28), a skin material (18) and The cushion material (20) is fixed to the inner shell (22) by a known means.
[0014]
As shown in FIG. 2, a slide fitting (26) and a screw fitting (28) are attached to the inner shell (22) by a set screw (30), whereby the inner shell (22) and the outer shell (24 ) Is movable up and down integrally with the backrest (10).
[0015]
FIG. 3 is a front view of the slide fitting (26) and the screw fitting (28), and FIG. 4 is a plan view thereof. As shown in FIG. 4, the slide fitting (26) is provided with a vertical rear recessed portion (26b) having a U-shape in a plan view at the center of the vertical substrate (26a), and the rear recessed portion (26b) A screw fitting (28) is attached to the front opening so as to close the opening by welding, thereby forming a substantially rectangular tubular portion (29) in plan view.
[0016]
An elliptical backrest ridge (12) is inserted into the cylindrical portion (29) to guide its vertical movement. A nut (32) as a female screw into which the thread portion (34a) of the screw (34) with handle is screwed is welded at a proper position of the screw fitting (28).
[0017]
FIG. 5 is a side sectional view showing a state in which the backrest (10) is lowered to the lowest height. As shown in the figure, a locking piece (26c) facing forward is formed on the upper portion of the cylindrical portion (29) by bending the center of the rearward recessed portion (26b) of the slide fitting (26). Has been. This locking piece (26c) comes into contact with the upper end of the backrest ridge (12) when the backrest (10) is lowered to the lowest height, and the backrest (10) falls inadvertently, and the handle screw ( This is to prevent the thread portion (34a) of 34) from being damaged due to a shearing force.
[0018]
As shown in FIG. 3, an upward U-shaped notch (35) is formed so as to surround the nut (32) at the lower front surface of the screw fitting (28). This notch (35) serves to facilitate the bending of the screw fitting (28) toward the backrest ridge (12) when the handle screw (34) shown in FIG. 1 is screwed onto the nut (32) and tightened. have. That is, when the backrest ridge (12) is pressed and fixed, the screw fitting (28) bends toward the backrest ridge (12) to facilitate surface contact with the surface of the backrest ridge (12).
[0019]
As shown in FIG. 1, a grip portion (34b) is provided at the rear end of the handle screw (34). A backrest ridge (12) is attached to the seat plate (14) so as to be tiltable by a pin (38), and a long long hole (36) is formed in the upper portion of the backrest ridge (12). .
[0020]
The threaded portion (34a) of the handle screw (34) is inserted into the elongated hole (36), and the threaded portion (34a) is screwed into the nut (32) of the screw fitting (28), thereby making the backrest back. The heel (12) is pressed between the slide fitting (26) and the screw fitting (28), that is, against the cylindrical portion (29), and the backrest (10) is fixed at an arbitrary height position. That is, due to the tightening force of the handle screw (34), the portion of the screw fitting (28) near the nut (32) bends in the direction of the backrest ridge (12) and makes surface contact with the surface of the backrest ridge (12). Thus, the backrest (10) is fixed by the frictional force.
[0021]
Therefore, the tightening force by the handle screw (34) for fixing the backrest (10) does not concentrate on one point of the backrest ridge (12), and the backrest ridge (12) is caused by the handle screw (34). Crushing by the tightening force can be prevented in advance. As a result, loosening and rattling during tightening can be effectively prevented.
[0022]
Thus, according to the height adjusting device of the present embodiment, when the backrest (10) is fixed, the tightening force applied to the backrest heel (12) is dispersed to prevent damage to the backrest heel (12). Can withstand long-term use.
[0023]
In addition, the backrest ridge (12) is fixed by the tightening force generated in the cylindrical portion (29) formed by the slide fitting (26) and the screw fitting (28). Strength is not required, and it is not necessary to provide a rib or a thick-walled structure on the outer shell (24). This improves the aesthetics and reduces the weight.
[0024]
Furthermore, since the backrest ridge (12) is guided by a cylindrical portion (29) that is vertically long, the backrest ridge (12) does not rotate around the handle screw (34), and the backrest (10) It is possible to prevent looseness and looseness.
[0025]
In the present embodiment, the shape of the backrest ridge (12) is substantially elliptical, but it is needless to say that it is formed in a shape that matches the cross-sectional shape of the cylindrical portion (29).
Moreover, in this embodiment, although the cylindrical part (29) is formed using two members, a slide metal fitting (26) and a screw metal fitting (28), it is not restricted to this, 1 formed in the cylinder shape It is good also as one member.
[0026]
【The invention's effect】
According to the present invention, the following effects can be achieved.
(a) According to the invention of claim 1, the backrest does not become loose or loose during use, and durability against long-term use can be improved.
[0027]
(b) According to the invention of claim 2, the cylindrical portion is provided with a notch, and the vicinity of the female threaded portion of the cylindrical portion can be bent in the front-rear direction. Such tightening force can be dispersed, and the backrest can be prevented from being crushed.
[0028]
(c) According to the invention of claim 3, since the cylindrical portion is disposed between the outer shell and the inner shell, the appearance is improved .
[0029]
(d) According to the invention of claim 4, when the backrest is lowered to the lowest limit, the upper end of the backrest and the locking piece at the upper part of the tubular portion come into contact with each other to restrict the downward movement of the backrest. As a result, the backrest can be prevented from inadvertently moving downward, and damage to the handle screw can be prevented.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a main part of a chair to which an embodiment of a chair height adjusting device of the present invention is applied as viewed from the front upper side.
2 is a cross-sectional view of the backrest of the chair in FIG. 1. FIG.
FIG. 3 is a front view of a slide metal fitting and a screw metal fitting which are main components of the embodiment.
4 is a plan view of the slide metal fitting and the screw metal fitting shown in FIG. 3. FIG.
FIG. 5 is a side sectional view showing a state in which the backrest is lowered to the lowest height.
[Explanation of symbols]
(10) Backrest
(12) Backrest
(14) Seat plate
(18) Skin material
(20) Cushion material
(22) Inner shell
(24) Outer shell
(26) Slide bracket
(26a) Vertical substrate
(26b) Backward recessed part
(26c) Locking piece
(28) Screw bracket
(29) Cylindrical part
(30) Set screw
(32) Nut
(34) Screw with handle
(34a) Screw part
(34b) Grip part
(35) Notch
(36) Long hole
(38) Pin

Claims (4)

A long elongate hole is drilled in the backrest saddle attached to the seat plate of the chair, and a cylindrical part for sliding the backrest saddle up and down is provided on the shell constituting the backrest of the chair. insert the threaded portion of the handle threaded into the long hole of the pre-Symbol cylindrical portion cylindrical portion clamping force caused by the internal thread can cause screwed into the said backrest rod by挾圧fix, of the backrest The height is adjusted, and the cylindrical portion is provided with a vertical rear recessed portion having a U-shape in plan view in the center portion of the vertical substrate, and a screw fitting is provided at the front opening of the rear recessed portion, A chair backrest height adjusting device, wherein the opening is formed by welding so as to close the opening .   2. The chair backrest height adjusting device according to claim 1, wherein a notch is provided around the female screw of the cylindrical portion, and a portion near the female screw of the cylindrical portion can be bent in the front-rear direction.   3. The chair backrest height adjusting device according to claim 1, wherein the cylindrical portion is disposed between the outer shell and the inner shell.   4. A locking piece is provided at an upper portion of the tubular portion, and when the backrest is lowered to the lowest limit, the upper end of the backrest and the locking piece are in contact with each other. The height adjustment device of the backrest of the chair as described in 2.

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