JPH10295486A - Chair - Google Patents

Abstract

PROBLEM TO BE SOLVED: To interlink the backrest of a chair with the support base allowing to lean without using a metal pipe. SOLUTION: A back outer shell 13 equipped with a back cover on the front surface and an axial support arm 14 installed facing frontward at the lower end of the back outer shell 13 are integrally formed from synthetic resin material. By supporting axially the end part 14a, an L-letter shaped at a side viedw, of an axial arm, of the backrest 6 in the axis-receiver 19 of a support base 3 supported by legs 2, by means of a backrest support shaft 10 facing right and left, the backrest can be leaned without using a metal pipe.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chair in which the structure for connecting a backrest to a support base supported on a leg is simplified and the strength of the chair is increased.

[0002]

2. Description of the Related Art As an example of attaching a backrest of a chair to a support base so as to be able to tilt backward, as described in Japanese Utility Model Publication No. 6-18537, a metal pipe is provided at the lower end of the backrest, and this metal pipe is attached. Some are pivotally attached to the foundation.

[0003]

However, the above-mentioned chair has the following problems. When used for a long time, the attachment portion of the backrest to the metal pipe is loosened, and every time it leans against the backrest, a squeak sound is generated, which gives a discomfort to the seated person and the surrounding people. It is necessary to apply grease to the shaft support of the metal pipe with respect to the support base, and when carrying the chair or adjusting the height of the chair, grease may adhere to the hand. The use of metal pipes makes it difficult to reduce the weight of the chair. Since the metal pipe is hard to bend, it is difficult to form the chair into a desired design.

[0004]

According to the present invention, the above-mentioned problem is solved as follows. (1) An L-shaped side view in which a back shell having a backrest on the front surface and a pivot arm connected to the lower end of the back shell facing forward are integrally formed of a synthetic resin material. The front end portion of the pivot arm of the backrest is supported by a support portion of a support base supported by a leg with a backrest support shaft facing in the left-right direction, whereby the backrest can be tilted rearward.

(2) In the above item (1), a rib extending in the front-rear direction is provided to project from the front surface of the outer shell to the upper surface of the pivot arm.

(3) In the above item (1) or (2), a pivot piece facing forward is provided at the front end of the pivot arm, before and after the upper end formed on the upper surface of the rear of the support base and the rear end are opened. The backrest support which is inserted in the backrest tilting groove facing in the direction, and which is formed in the bearing portion of the side wall on both sides of the backrest tilting groove and has a U-shape in a side view, and which penetrates the shaft support piece, supports the left and right direction. The shaft is inserted from above and the upper end opening of the bearing groove is closed by a closing member.

(4) In the above item (3), a pair of pivot pieces are formed in the left-right direction of the front end of the pivot arm, and a pair of backrest tilting grooves are formed in the left-right direction of the rear upper surface of the support base. .

(5) In the above item (3) or (4),
The thickness of the bearing portion in the left-right direction is made thicker than other portions.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS. The chair (1) of the present invention comprises a support (3) having legs (2) and armrests (7) (one leg and armrest are not shown) on both left and right sides, and a torsion provided on the support (3). A bar (4), a seat (5) provided directly to the support (3) or via a torsion bar (4), and a tiltable front and rear direction connected to the support (3); A backrest (6) also connected to (5) is provided.

As shown in FIG. 3, the leg (2) is connected to the bolt (8).
Attached to the support (3). Left and right armrests (7)
The backrest (6) having the backrest (11) is provided on the support base (3) so as to be tiltable in the front-rear direction by the armrest support shaft (9) and the backrest support shaft (10). . The armrest (7) and the backrest (6) are integrally tilted in the front-rear direction.

As shown in FIG. 3, the upper end of the armrest (7) is attached to an intermediate portion of the backrest (6). Therefore, armrest
The tilting centers of (7) and the backrest (6) must coincide with each other, and the armrest support shaft (9) and the backrest support shaft (10)
Four (two are omitted in the figure) for convenience are arranged in the support base (3) in the left-right direction with their axes aligned.

As shown in FIG. 2, a pair of left and right pressing pieces (12) that contact the rear end of the torsion bar (4) from above are provided on the left and right sides of the backrest (6). The pressing piece (12) is rotatably provided on the backrest (6) by protruding shafts (not shown) projecting from both left and right sides of the pressing piece (12). The torsion bar (4) has a function of receiving the backward inclination of the backrest (6) by elasticity via the pressing piece (12).

As shown in FIG. 1, the backrest (6) includes an outer shell (13) having a backrest (11) on the front surface, and an outer shell (13).
And a pivot arm (14), which is connected to the lower end of the body and faces forward, is integrally formed of a hard synthetic resin material to form an L-shape in a side view.

A backrest reinforcing rib (15) extending in the front-rear direction from the front surface of the outer shell (13) to the upper surface of the pivot arm (14).
However, a plurality of them are arranged in the left-right direction.

At the tip (14a) of the pivot arm (14), a pair of left and right pivot supports (16) facing forward is formed integrally with the pivot arm (14) by a hard synthetic resin material. I have. A pair of shaft supports (16)
Are inserted into a pair of right and left backrest tilting grooves (17) formed on the rear upper surface of the support base (4) and having the upper end and the rear end open in the front-rear direction (the lower end also in this embodiment). .

As shown in FIG. 1, FIG. 4 and FIG.
6), a backrest support shaft (10) is provided in the left-right direction via a bush (18).

Both ends of the backrest support shaft (10) are provided with backrest tilting grooves.
It is pivotally supported by U-shaped bearing grooves (20) formed in the bearing portions (19) (19) on both side walls of (17). The thickness of the bearing portion (19) in the left-right direction is thicker than other portions. As shown in FIG. 5, a stopper flange (10a) is provided at one end of the backrest supporting shaft (10), and a stopper protrusion (21) is provided on the support base (21) in opposition to the flange (10a). 3) It protrudes.

In order to prevent the backrest support shaft (10) from falling upward, a closing member (22) for closing the upper end opening of the bearing groove (20) is provided on the bearing portion (19) with a screw (22). 23). The closing member (22) also receives the shaft support (16) in order to regulate the amount of vertical tilt of the shaft support (16) due to the backward tilt of the backrest (6). . Therefore, the closing member (22) is formed in a V-shape in cross-sectional side view,
The front half portion is a rearward tilt restriction surface (22a), and the rear half portion is a front tilt restriction surface (22b).

The backrest (6) and the support (3) are connected by inserting the backrest support shaft (10) into the bearing groove (20) from above and closing the closing member (2).
This is performed by screwing 2) to the bearing portion (19) from above.

As shown in FIGS. 1, 2 and 4, the distal end (14a) of the pivot arm (14) has an inverted L-shaped excessively backward restricting piece as viewed from the side.
(24) is provided. A buffering piece (25), which is a pad, is provided on the support base (3) opposed to the backward inclination regulating piece (24). The cushioning piece (25) is mounted in a concave portion (27) of a projecting piece (26) projecting rearward from the rear end of the support base (3). Note that the buffer piece (25) is not provided on the protruding piece (26) of the support base (3),
(24) may be provided.

Next, the operation will be described. When a person sits on the chair (1) and takes a comfortable posture, a rearward force is applied to the backrest (6), and the backrest (6) tilts backward about the backrest support shaft (10), and the pressing piece ( Press the torsion bar (4) via 12). At this time, the backrest (6) and the pivot arm (14) are hardly deformed because they are reinforced by the reinforcing ribs (15).

When the leaning force of the seated person against the backrest (6) and the elasticity of the torsion bar (4) are balanced, the backward leaning of the backrest (6) stops.

When the backrest (6) is greatly inclined backward,
The back leaning control piece (24) comes in contact with the buffer piece (25),
(6) Relieve the impact by preventing the backward tilt, and then use the shaft support (16)
However, it comes into contact with the rearward inclination restricting surface (30a) of the closing member (30), restricts the rearward inclination of the backrest, and prevents the seated person from rolling backward.

When the seated person leaves the chair, the backrest (6) is tilted forward by the torsion bar (4),
When the shaft support piece (16) comes into contact with the forward leaning restricting surface (22b) of the closing member (22), it is regulated forward leaning and returns to a predetermined standing state.

As a modified example of the backrest support shaft, there may be a single backrest support shaft that straddles all the bearing portions. One pivot piece may be formed in the middle of the front end of the pivot arm in the left-right direction, and one backrest tilting groove may be formed in the center of the rear upper surface of the support base in the left-right direction.

[0026]

According to the first aspect of the present invention, since the outer shell is connected to the supporting base by the pivot arm integrally formed with the outer shell and the synthetic resin material, the following effects can be obtained.
No squealing sound is generated, and no discomfort is given to the seated person and the surrounding people. Grease injection is not required, and grease does not adhere to the hand when adjusting the height of the chair. The chair can be made lighter by making the backrest lighter. Processing of the backrest is easy, and the chair can be formed in a desired design. The structure of the backrest can be simplified, and the cost of the chair can be reduced.

As in the second aspect of the present invention, when a rib extending in the front-rear direction is projected from the front surface of the outer shell to the upper surface of the pivot arm, the backrest can be reduced in weight and rigidity can be increased.

According to a third aspect of the present invention, a pivotal support piece is provided at the front end of the pivot arm, and the backrest is formed on the rear upper surface of the support base and has a forward and rearward opening at the rear end. The backrest support shaft is inserted into the tilting groove, and a leftwardly-facing backrest support shaft penetrating the shaft support piece is inserted from above into a U-shaped bearing groove formed in the bearing portion on both side walls of the backrest tilting groove. When the upper end opening of the bearing groove is closed by a closing member, the backrest and the member connecting the backrest to the support base can be sequentially incorporated from above, thereby facilitating the assembly of the chair.

According to a fourth aspect of the present invention, a pair of pivot pieces are formed in the left and right direction of the front end of the pivot arm, and a pair of backrest tilt grooves are formed in the left and right direction of the rear upper surface of the support base. In this case, the backrest can be tilted backward in a stable state.

When the thickness of the bearing portion in the left-right direction is greater than that of the other portions, the strength of the rearwardly inclined bearing portion of the backrest can be increased.

[Brief description of the drawings]

FIG. 1 is a perspective view of a backrest, a support base and legs of a chair according to an embodiment of the present invention.

FIG. 2 is a sectional side view of a lower portion of a seat, a support base, and a backrest.

FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 2, in which a right half is omitted.

FIG. 4 is a side view of a connecting portion between the support base and the backrest, which is partially shown in section.

FIG. 5 is a sectional view taken along the line VV in FIG. 4;

6 is a sectional view taken along the line VI-VI in FIG.

[Explanation of symbols]

 (1) Chair (2) Leg (3) Base (4) Torsion bar (5) Seat (6) Backrest (7) Armrest (8) Leg mounting bolt (9) Armrest support shaft (10) Backrest support Shaft (10a) Retaining collar (11) Backrest (12) Pressing piece (13) Outer shell (14) Pivot arm (14a) Tip of pivot arm (15) Reinforcing rib (16) Shaft piece (17) Backrest tilting groove (18) Bush (19) Bearing (20) Bearing groove (21) Retaining protrusion (22) Closure member (22a) Backward tilt regulating surface (22b) Forward tilt regulating surface (23) Screw (24) Excess tilt control piece (25) Buffer piece (26) Projection piece (27) Recess

Claims (5)

[Claims] 1. An outer shell having a backrest on a front surface, and a pivot arm connected to a lower end of the outer shell facing forward,
A front end portion of the pivot arm of an L-shaped backrest integrally formed of a synthetic resin material is pivotally supported on a bearing portion of a support base supported by a leg with a backrest support shaft facing in the left-right direction. A chair, wherein the backrest can be tilted backward. 2. The chair according to claim 1, wherein a rib extending in the front-rear direction extends from the front surface of the outer shell to the upper surface of the pivot arm. 3. A front-facing shaft support piece is inserted into a front-rear tilting groove formed in a rear upper surface of a support base and opening in a front-rear direction and extending in a front-rear direction at a front end of the pivot arm. A left-back support shaft extending in the left-right direction that penetrates the shaft support piece is inserted from above into a U-shaped bearing groove formed in the side wall of the backrest tilting groove in the bearing portion on both side walls. 3. The chair according to claim 1, wherein the upper end opening is closed by a closing member. 4. A pair of pivotal support pieces are provided in the left-right direction at the front end of the pivot arm, and one backrest tilting groove is provided in the left-right direction on the rear upper surface of the base.
4. The chair according to claim 3, which is formed as a pair. 5. The chair according to claim 3, wherein the thickness of the bearing portion in the left-right direction is thicker than other portions.