JP2002136388A - Backrest structure for chair - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simply-structure good-appearance backrest structure for a chair capable of preventing damage in another object or in a back lever itself even if the back lever collides against the object when the chair is turned. SOLUTION: In the chair, a back plate 5 is supported by means of a pair of left and right metallic back levers 6 extended backward from beneath a seat 8 to the upper side, and the back face and the outside face of each back lever 6 are covered with a cover 22 made of a soft material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backrest structure for a chair, and more particularly to a backrest structure for supporting a backboard.

[0002]

2. Description of the Related Art In a chair with a conventional caster, a back bar for supporting a back plate extends rearward and upward from below a seat, and an upper end portion thereof is fixed to a rear surface of the back plate, or a back plate of the back plate. Many are designed to be inserted inside.

[0003] Some simple chairs without casters have upper portions of left and right back rods attached to both side surfaces of a back plate.

[0004]

As described above, in a conventional chair with casters, the metal back rod is rarely arranged behind the seat and outside the side end of the seat. However, some recently developed chairs have one
Placing a pair of metal back rods outside the side end of the seat, or forming a square frame frame integrally with the back rod,
Some frames support a flexible backrest.

In this type of chair, when the backrest is swiveled around the pillar together with the seat, the metal back rod abuts on the desk or cabinet and damages them, or the outer surface of the back rod is damaged. There is a possibility that it will be lost.

The present invention has been made in view of the above-mentioned problems of the prior art, and when the chair is turned, the back rod comes into contact with another object and damages the back rod, or the back rod itself is damaged. It is an object of the present invention to provide a chair backrest structure having a simple structure and a good appearance.

[0007]

According to the present invention, the above-mentioned problems are solved as follows. (1) In a chair in which a back plate is supported by a pair of left and right metal back bars extending rearward and upward from below the seat, a rear surface and an outer surface of each back bar are made of a soft material. Cover with cover.

(2) In the above item (1), a low step is formed from the rear surface to the outer surface of the upper part of the back rod, and a cover having substantially the same thickness as the depth is fitted into the low step. Stop.

(3) In the above item (1) or (2), a plurality of engaging projections having elastically deformable engaging claws at a tip thereof are provided on the inner surface of the cover, and each engaging projection corresponds to each of them. The cover is fastened to the back rod by fitting into engagement holes formed in each part of the back rod.

(4) In any one of the above items (1) to (3), a vertically extending concave portion having an open front surface is provided on an upper portion of the back rod, and the concave portion is provided on both sides of the back plate. A rearward projection formed on the lower rear surface of the formed vertical side frame portion is fitted to fix the upper portion of the back rod and the lower portion of the side frame portion to each other,
In addition, the outer shape of the upper part of the side frame portion is formed to be continuous with the outer surface of the cover attached to the back rod.

[0011]

An embodiment of the present invention will be described below with reference to the accompanying drawings. As shown in FIG. 1, casters (2) are respectively provided at the distal ends of the support legs (1) extending radially from the center, and the center of the support legs (1) is
A pillar (3) is erected, and a support base is provided at the upper end of the pillar (3).
(4) is fixed.

A lower front end of a pair of right and left back bars (6) supporting the back plate (5) is formed on the support base (4) so as to extend rearward and upward in an L shape in a side view. Pivoted with the facing axis (7),
The back plate (5) and the back rod (6) can be tilted rearward from the standing position shown in FIG. 1 by a desired angle by an elastic reclining mechanism (not shown) provided in the support base (4). ing.

Above the support (4), a seat (8) is provided.
Via (9), the back plate (5) and the back rod (6) are supported so as to move rearward and downward in conjunction with the backward tilt.

Armrests (10) are provided on both sides of the seat receiver (9) via support rods (9a) extending in the left-right direction.

As shown in FIG. 2 and subsequent figures, the back plate (5) is integrally formed of a synthetic resin material, has a substantially vertical rectangular front face, and has upper and lower slits in the vicinity of both sides in the vertical direction.
(11) By cutting the (11a), the portion outside the slits (11) and (11a) is not easily deformed and has a high rigidity side frame (1).
2), and the portion inside the slits (11) and (11a) is a flexible low-rigidity backrest (13). The upper and lower ends of the upper slit (11) are closed, the upper end of the lower slit (11a) is closed, and the lower end is open to the lower end of the back plate (5).

The upper portion (12a) of the side frame portion (12) is substantially above the center,
The V-shape or semi-arc shape having an open front surface, or an intermediate shape thereof, increases the thickness of the same portion in the front-rear direction to increase rigidity.

At a lower portion (12b) of the side frame portion (12) from a substantially lower portion (12b), a plurality of portions (3 in the illustrated example) having a front surface in a flat plate shape and a rear surface having a height of the center portion are provided. Article) rib
By projecting the (14), a rearward projecting portion (15) projecting backward in a chevron is formed.

Bosses (16) projecting rearward are formed at two places on the upper and lower rear surfaces of the lower part (12b).
At the center of 6), a screw insertion hole (17) penetrating from the rear end to the front surface of the back rod (12) is formed.

The left and right back rods (6) are made of aluminum light alloy or other metal material, and are formed with a vertically extending concave streak (6a) which opens forward in the front surface of the upper part, so as to cross the upper part. The surface shape is a substantially V-shaped or semi-circular shape with an open front surface, or an intermediate shape between them.

A lower portion (12b) of the side frame portion (12) is inserted into the concave strip (6a).
And the upper end of the back rod (6) is
Step (1) between the upper part (12a) and the lower part (12b) in the side frame part (12)
A boss provided in a portion corresponding to the boss (16) of the back rod (6) is provided with a set screw (18) (see FIG. 7) which abuts on the screw insertion hole (17) from the front surface of the back rod (6). By screwing into the screw hole (20) in the center of the part (19), the lower part of the side frame part (12)
(12b) is firmly connected to the upper part of the back bar (6).

A low step portion (21) is formed from the rear surface to the outer surface of the upper part of the back rod (6), and the outer shape is part of the upper part (12a) of the side frame part (12). A cover (22) made of a synthetic resin or rubber material having elasticity substantially the same shape as that of the low step portion (21) and having the same thickness as the depth of the low step portion (21).
An engaging projection (24) projecting from the front surface of the cover (22) and having an elastically deformable locking claw (23) at the tip end
The cover (22) is fastened to the back rod (6) by fitting it into an engagement hole (25) drilled at a key point on the back of the back rod (6).

By attaching the cover (22) to the back rod (6), the rear end of the screw hole (20) drilled in the back rod (6) is covered, and the appearance is improved, and the cover is made of metal. Certain back bars (6) are protected to prevent the back bars (6) from hitting and damaging desks, cabinets and the like.

Thus, the side frame portion (12) of the back plate (5) forms a part or extension of the original back rod (6), and the frame of the frame that firmly supports both sides of the back plate (5). Has a role.

As shown in FIG. 1, the side frame portion (12) of the back plate (5)
The back bar (6) and the cover (22) are integrated with each other to give a gentle S-shape as a whole and a sophisticated appearance.

The thickness of the back support (13) in the back plate (5) in the front-rear direction is smaller than the thickness of the side frame (12) in the front-rear direction. It has flexibility.

A bent portion (27) is formed at an intermediate portion in the vertical direction of the back support portion (13) by cutting off the other portions except for three flexible pieces (26) at the center and left and right. I have.

Due to the presence of the bent portion (27), the back support (1)
3) is divided into an upper part (13a) and a lower part (13b), and when the occupant leans strongly against the back support part (13), especially when the back plate (5) is tilted rearward, this is done. At this time, the bent portion (27) moves rearward from the other portion, and the upper portion (13a) and the lower portion (13b) bend in a side-view shape. Thereby, even if the backboard (5) is tilted backward,
The head of the seated person does not lean backward and is maintained almost vertically, and in a comfortable posture, the eyes can be maintained so as to always face forward.

Each of the flexible pieces 26 has a mountain shape or a U-shape in which the top is directed forward in a side view. This makes it easier for the upper part (13a) and the lower part (13b) to bend from each other about the top of the flexible piece (26) as the center of rotation. That is, the flexible piece
When (26) is disposed so that its top is directed rearward, the flexible piece (26) becomes self-closing when the back support (13) bends as described above, and a vertical pulling force is applied to the top. Act, upper and lower
Although (13a) and (13b) are less likely to bend, in the case of the present embodiment, the flexible piece (26) becomes freely opened and the upper and lower portions (13a) (13)
b) is easily bent.

In the upper portion (13a) and lower portion (13b) of the back support portion (13), a number of lightening holes (28) (or may be thin portions) of a horizontally long hexagon or any other shape are formed. The upper part (13a) and the lower part (13
The flexibility of b) is further enhanced.

A bent piece (29) extending rearward is provided at the upper edge of the back plate (5). By the bent piece (29), the rigidity of the upper end of the back plate (5) is increased, and the bent piece (29) functions as an upper frame and is used to lock an upper edge of a cushion body (30) described later. It can also function as a projection and as a handle when moving the chair.

The lower end of the lower portion (13b) of the back support portion (13) is completely separated from the frame portion (12) by the left and right slits (11a) and extends forward and downward, and the rear end of the seat (8) It is connected to.

The cushion body (30) is formed so as to substantially cover the entire front surface of the back plate (5), and has, at its upper end, a winding portion (26) for winding the rear end of the bent piece (29) of the back plate (5). 30a) is formed.

[0033]

According to the present invention, the following effects can be obtained. According to the first aspect of the present invention, even when the back rod projects from the back plate or the seat on both sides or rearward, the rear surface and the outer surface are covered by the elastic cover. Can be prevented from directly abutting against a desk, cabinet, or the like to damage them or damage the outer surface of the back rod.

According to the second aspect of the present invention, since the outer surface of the cover substantially coincides with the outer surface of the back bar, the appearance is good.

According to the third aspect of the present invention, the cover can be easily attached to and detached from the back bar.

According to the fourth aspect of the present invention, the lower portion of the side frame portion of the back plate can be firmly connected to the upper portion of the back bar, and the outer shape of the upper portion of the side frame portion matches the outer surface of the cover below it. Since it is continuous, the appearance is good. Particularly, in combination with the structure of claim 2, the exposed outer surface of the back rod, the outer surface of the cover, and the outer surface of the upper portion of the side frame portion of the back plate are continuous, and they are formed. It looks like a single back rod and can have a beautiful appearance.

[Brief description of the drawings]

FIG. 1 is a side view of a chair provided with an embodiment of the present invention.

FIG. 2 is also a rear view.

FIG. 3 is a front perspective view of the back plate.

FIG. 4 is a rear view of the left half of the back plate.

FIG. 5 is a side view of the back plate.

FIG. 6 is an exploded perspective view of a back bar and a cover.

FIG. 7 is a cross-sectional exploded plan view taken along the line VII-VII of FIG. 4;

8 is a cross-sectional exploded plan view taken along the line VIII-VIII of FIG.

[Explanation of symbols]

 (1) Support leg (2) Caster (3) Pillar (4) Support base (5) Back plate (6) Back rod (6a) Concave strip (7) Shaft (8) Seat (9) Seat receiver (9a ) Support (10) Armrest (11) (11a) Slit (12) Side frame (12a) Upper (12b) Lower (12c) Step (13) Back support (13a) Upper (13b) Lower (14) Rib (15) Rearward projection (16) Boss (17) Screw insertion hole (18) Set screw (19) Boss (20) Screw hole (21) Low step (22) Cover (23) Locking claw (24) Engagement protrusion (25) Engagement hole (26) Flexible piece (27) Bent part (28) Lightening hole (29) Bend piece (30) Cushion body (30a) Entrainment part

Claims (4)

[Claims] 1. A chair in which a back plate is supported by a pair of left and right metal back bars extending rearward and upward from below the seat, the rear surface and the outer surface of each of the back bars are made of a soft material. The backrest structure of the chair, which is covered with a cover made of steel. 2. A low step portion is formed from the rear surface to the outer surface of the upper portion of the back rod, and a cover having substantially the same depth as the lower step portion is fitted and fixed to the low step portion. Chair backrest structure. 3. A plurality of engaging projections having an elastically deformable engaging claw at a tip thereof are provided on an inner surface of the cover, and each of the engaging projections is
3. The cover is fixed to the back rod by fitting into an engagement hole formed in each part of the back rod corresponding thereto.
The backrest structure of the chair described. 4. An upper surface of a back rod is provided with a vertically extending concave streak having an open front surface, and the concave streak is formed at a lower rear surface of a vertically oriented side frame portion formed on both sides of a back plate. The rear projection is fitted to fix the upper part of the back rod and the lower part of the side frame part to each other, and the outer shape of the upper part of the side frame part is continuous with the outer surface of the cover attached to the back rod. Claim 1
4. The backrest structure according to any one of claims 1 to 3. Chair backboard.