JP2003135194A - Chair seat back - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chair seat back which is excellent in design and strength by firmly connecting a back frame and a seat frame without welding. SOLUTION: The chair seat back is constituted by connecting a back frame 10 to the seat frame 3 supporting a seat. The back frame 10 includes left and right side rods 8 directed in a vertical direction and a horizontal rod 9 for connecting the upper ends of the left and right side rods. The lower parts of the respective side rods 8 in the back frame 10 are fitted to left and right vertical fitting holes 11b which are arranged in the neighborhood of the both ends of a horizontal lower frame 11. Besides, the seat frame 3 is fixed with horizontal fastening screws 7 to recessed receiving parts 11a which are provided at the both ends of the lower frame 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backrest of a chair in which a back frame is joined to a seat frame that supports a seat.

[0002]

2. Description of the Related Art In a conventional backrest of a chair, a lower part of a back frame made of a round metal pipe is joined to a seat frame for supporting a seat, and a flexible thread-like material is used for the back frame. For example, there is one in which a tension material made by knitting a thread-like synthetic resin material in a mesh shape is stretched.

[0003]

In the backrest of the chair as described above, since the upholstery material itself has no rigidity, the upholstery material cannot reinforce the back frame, which may lead to insufficient rigidity of the back frame. There is. In order to solve this lack of rigidity of the back frame, it is necessary to form the back frame and the seat frame with a thick round pipe material, and firmly fix the back frame and the seat frame by welding or the like.

However, in such a case, not only the balance of the entire chair is deteriorated by the thick round pipe material, but also the welded portion is exposed and the appearance is deteriorated, which may adversely affect the design.

In view of the above-mentioned problems of the prior art, the present invention is a chair which can firmly connect the back frame and the seat frame without welding and is excellent in design and strength. The purpose is to provide a backrest.

[0006]

According to the present invention, the above problems can be solved as follows. (1) In a backrest of a chair formed by connecting a back frame to a seat frame that supports a seat, the back frame includes:
It has left and right side rods facing the up-down direction and horizontal rods connecting the upper ends of the left and right side rods, and the lower part of each side rod of the back frame is located near both ends of the lower frame facing the left-right direction. The seat frame is fixed to the recessed receiving portions provided at both ends of the lower frame, which are fitted in the left and right fitting holes provided in the vertical direction, by the tightening screws facing in the left and right direction.

(2) In the above item (1), the tightening screw is
The seat frame and the lower frame are fitted to the through holes provided in the seat frame and the lower frame in the lateral direction, and are screwed into the female screw holes provided on the back frame side so that the seat frame and the lower frame are connected to each other of the back frame. Tighten the lower part of the side rod together.

(3) In the above item (2), the seat frame is provided with a cover capable of closing the through hole of the seat frame.

(4) In the above item (3), the cover is provided with a protrusion that can be fitted into the through hole of the seat frame.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of the chair before mounting the backrest, and FIG. 2 is a perspective view of the chair after mounting the backrest.

The chair (1) includes a seat portion (2) supported by legs (not shown), right and left upward seat frame portions (3) connected to the lower surface of the seat portion (2), Each seat frame (3) is provided with a backrest (4) connected as described below.

Each seat frame (3) is formed of a metal round pipe material, and has two upper and lower through-holes (5) on the outer peripheral surface facing in the left-right direction, and a peripheral surface which also faces the inner surface. Mainly, as shown in FIG. 4, mounting holes (6) facing the respective through holes (5) are formed in each.

The diameter of each through hole (5) is such that the head portion (7a) of the fastening screw (7), which will be described later in the left-right direction, can penetrate, as shown mainly in FIG. The diameter of the mounting hole (6) is smaller than that of the through hole (5), and the head (7a) of the fastening screw (7) can abut the peripheral edge of the mounting hole (6).

The backrest (4) is formed of a metal round pipe material, and connects the upper ends of the left and right side rods (8) (8) and the left and right side rods (8) (8) facing each other in the vertical direction. A front frame having a substantially inverted U-shaped back frame (10) having a horizontal rod (9) and a hard synthetic resin fixed to the lower part of each side rod (8) (8) in the back frame (10) or A lower frame (11) made of aluminum alloy that faces in the left-right direction and a flexible thread-shaped material stretched on the back frame (10), for example, a tension material (12) woven from a thread-shaped synthetic resin material in a mesh shape. It is formed from and.

The upholstery material (12) is attached to each of the side rods of the back frame (10) on a cylindrical portion (12a) provided at its upper edge and left and right side edges.
The lower frame (11) is fixed to the back frame (1) by inserting the (8) and the horizontal rod (9) through the lower frame (11).
It will be installed in 0).

The lower frame (11) has two left and right ends,
Each seat frame (3) has a recessed receiving part (11a) in which a part of the outer peripheral surface fits, and in the vicinity of each recessed receiving part (11a), the back frame is penetrated in the vertical direction. There is a fitting hole (11b) into which the lower part of each side rod (8) in 10) is fitted.

In each concave receiving portion (11a) of the lower frame (11), there are two upper and lower through holes (13) facing in the left-right direction and a tightening hole (1).
4) is provided. The inner ends of the through holes (13) and the fastening holes (14) communicate with the fitting holes (11b).

Inside the lower part of each side rod (8) in the back frame (10), there is a columnar body (15) having a predetermined length in the vertical direction.
(Shown in cross section in FIGS. 4-6).
A female screw hole (16) into which the fastening screw (7) is screwed is provided in a portion of the columnar body (15) that matches each through hole (13).

The lower parts of the side rods (8) of the back frame (10) are fitted in the fitting holes (11b), and the screws (17) pointing in the left-right direction are fastened to the fastening holes (11) of the lower frame (11). 14)
The lower frame (11) is fixed to the back frame (10) by being screwed into a female screw hole (not shown) provided in the columnar body (15).

As shown in FIG. 1, the back frame (10) connected to the lower portion of each side rod (8) of the lower frame (11) is
It is fixed to each seat frame (3) through the lower frame (11) with a fastening screw (7). I.e. seat frame
With the peripheral surface of (3) facing inward in the left-right direction fitted into the concave receiving portion (11a) of the lower frame (11), the fastening screw
(7) from the through hole (5) of the seat frame (3) to the mounting hole (6)
And the through hole (13) of the lower frame (11),
It is screwed into the female screw hole (16) of 5).

As a result, the seat frame (3) and the lower frame (11) are screwed together as shown in FIGS. 2 and 4.
The lower frame (11) reinforces the back frame (10) by tightening the lower frame (11) together with the lower parts of the side rods (8) of the back frame (10) by the (7), and the rigidity of the back frame (10) is improved. To be enhanced.

Reference numeral (18) is a substantially semi-cylindrical cover made of elastically deformable synthetic resin, which is attached to each seat frame (3) so that each through hole of the seat frame (3) is opened.
(5) can be hidden.

As shown in FIG. 3, the inner peripheral surface of the cover (18) mainly protrudes toward the seat frame (3) side and is formed in each through hole (5) of the seat frame (3). Cylindrical protrusion that can be fitted
(18a) and (18a) are provided.

To attach the cover (18), the cover (18) is directed in the direction of the arrow as shown in FIG.
It is pressed against the portion where each through hole (5) in (3) is provided. As a result, the cover (18) is pushed while expanding against the elastic force as shown in FIG. 5, and then clamps the outer peripheral surface of the seat frame (3) as shown in FIG. With
Each protrusion (18a) is fitted into each through hole (5) of the seat frame (3) and is fixed to the seat frame (3).

By fitting the respective protrusions (18a) into the respective through holes (5), the cover (18) can be reliably positioned and the displacement of the cover (18) can be prevented. it can.

When the cover (18) is attached to the seat frame (3), as shown in FIG.
Both edges (18b) of 8) are concave receiving parts (11a) of the lower frame (11).
Close to. As a result, the concave receiving part of the lower frame (11)
The (11a) is also hidden by the cover (18), and the appearance can be further improved.

FIG. 7 is a cover according to the embodiment of the present invention.
A modification of (18) will be shown. The protrusion (18c) provided on the inner peripheral surface of the cover (18) is formed in a prismatic shape so that it can be fitted into each through hole (5) of the seat frame (3).

Also in this modification, similarly to the above-mentioned embodiment, the projection (18c) is fitted into each through hole (5) of the seat frame (3), so that the cover (18) is reliably positioned. It is possible to prevent the displacement of the cover (18).

[0029]

According to the present invention, the following effects can be obtained. (A) According to the invention of claim 1, the lower portions of the side rods of the back frame are fitted into the vertically fitting left and right fitting holes provided in the vicinity of both ends of the lower frame facing the left and right directions, By fixing the concave receiving parts provided at both ends of the frame to the seat frame with the fastening screws that face in the left-right direction, the back frame and the seat frame can be connected nicely and the back frame can be connected by the lower frame. The rigidity can be increased, and the design and strength can be improved.

(B) According to the invention described in claim 2, in addition to the effect of claim 1, the seat frame and the back frame can be firmly coupled, and the number of fastening screws used is reduced. be able to.

(C) According to the invention of claim 3, in addition to the effect of claim 2, the through hole of the seat part frame is concealed by the cover, and the appearance can be improved.

(D) According to the invention of claim 4, in addition to the effect of claim 3, the cover is positioned by the fitting of the projection of the cover and the through hole of the seat part frame, which is simple and easy. It can be securely attached to the seat frame.

[Brief description of drawings]

FIG. 1 is a perspective view of a chair before mounting a backrest equipped with an embodiment of the present invention.

FIG. 2 is likewise a perspective view of the chair after the backrest is attached.

FIG. 3 is likewise a perspective view of a main part.

FIG. 4 is likewise an enlarged cross-sectional view of the main part before the cover is attached.

FIG. 5 is likewise an enlarged cross-sectional view of a main part during the attachment of the cover.

FIG. 6 is likewise an enlarged cross-sectional view of a main part after the cover is attached.

FIG. 7 is likewise a perspective view showing a modified example of the cover.

[Explanation of symbols]

(1) Chair (2) Seat (3) Seat frame (4) Backrest (5) Through hole (6) Mounting hole (7) Fastening screw (7a) head (8) Side rod (9) Yokoki (10) Back frame (11) Lower frame (11a) Recessed receiving part (11b) Mating hole (12) Upholstery material (12a) Cylindrical part (13) Through hole (14) Tightening hole (15) Cylindrical body (16) Female screw hole (17) Screw (18) Cover (18a) (18c) Projection (18b) Edge

Claims (4)

[Claims] 1. A backrest of a chair, comprising a seat frame supporting a seat and a back frame, wherein the back frame has left and right side rods facing up and down and upper ends of the left and right side rods. Having a horizontal rod connecting the two, the lower portion of each side rod of the back frame, fitted in the vertical fitting left and right fitting holes provided in the vicinity of both ends of the lower frame facing the left-right direction, A backrest of a chair, characterized in that the seat frame is fixed to the recessed receiving portions provided at both ends of the lower frame with tightening screws pointing in the left-right direction. 2. The seat frame and the seat frame by fitting a tightening screw into a through hole provided in the seat frame and the lower frame in the lateral direction and screwing into a female screw hole provided on the back frame side. The backrest of the chair according to claim 1, wherein the lower frame and the lower frame are fastened together to the lower portions of the side rods. 3. The backrest of a chair according to claim 2, wherein the seat frame is provided with a cover capable of closing a through hole of the seat frame. 4. The backrest of a chair according to claim 3, wherein the cover is provided with a protrusion that can be fitted into the through hole of the seat frame.