JPH1156519A - Shell structure for chair - Google Patents

Abstract

PROBLEM TO BE SOLVED: To mold a shell by a simple metallic mold which is divided in two directions in a shell structure constituted by mutually connecting a middle shell and an outer shell in a chair. SOLUTION: Restraining means provided in one of the middle shell 2 provided with a cushion body on one side surface or the outer shell 3 for covering the other side surface of the middle shell 2 are engaged with receiving parts which are formed in the other shell so that the both shells are mutually connected. Then, the restraining means 9 are provided with base shafts which are projectedly provided in one shell and restraining pieces 9 which are connected to the base shafts 11 by the connecting means 12 by forming flange-shaped projecting pieces. The projecting pieces of the restraining pieces 9 are engaged with the receiving parts so that the both shells are mutually connected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shell structure for a seat or backrest of a chair in which an outer shell is connected to the other side of a middle shell having a cushion body provided on one side.

[0002]

2. Description of the Related Art A shell structure applied to a backrest or a seat of a chair is disclosed in Japanese Utility Model Publication No. 7-21154. In this shell structure, the two shells are connected to each other by fitting a locked hole on the middle shell side and a shaft portion on the outer shell side.

In this shell structure, a shaft portion on the outer shell side has
Since it has a flange-shaped protruding piece formed integrally with the outer shell and locked in the hole to be locked, it can simply be 2 in the thickness direction of the shell.
When the outer shell is molded with a two-part mold that splits into two,
The protruding pieces do not come off from the mold, making molding impossible. Therefore, this shell structure cannot be formed unless a mold having a slide piece that moves in a direction different from the main mold separation direction is used for forming the protruding pieces, and the mold cost increases. is there.

A shell structure capable of coping with this problem is disclosed in Japanese Utility Model Publication No. 1-16464. In this shell structure, a shaft portion having a projecting piece is formed separately from the outer shell to form a shaft piece, the shaft piece is inserted into a recess of the outer shell, and a retaining piece integrally formed with the shaft piece is formed into a recess. The shaft piece and the outer shell are integrated by engaging with a large-diameter portion formed at the bottom of the shaft. For this reason, this shell structure can be manufactured by an ordinary mold in which the molding of the outer shell is simply divided into two directions.

[0005]

However, in the shell structure described in the latter publication, it is necessary to form a large-diameter portion larger than the entrance diameter of the recess, that is, an undercut portion, at the bottom of the recess. However, after forming the protruding piece for the large diameter part in the mold, after forming the outer shell, the protruding piece must be forcibly extracted from the outer shell, which shortens the life of the mold and easily causes molding defects. is there.

[0006] In view of the above problems, the present invention forms a portion corresponding to the shaft portion having the protruding piece separately from the shell, without forming the above-described undercut portion in the shell. The shell can be mounted so that
It is an object of the present invention to provide a chair shell structure that can be operated with a simple mold that is divided in directions.

[0007]

According to the present invention, the above-mentioned problem is solved as follows. (1) a middle shell in which a cushion body is provided on one side,
A chair formed by connecting the shells to each other by engaging a locking means provided on one shell with an outer shell covering the other side surface of the middle shell on a receiving portion formed on the other shell. In the shell structure for use, the locking means has a base shaft protruding from the one shell, a flange-shaped protruding piece engaging with the receiving portion at one end, and formed at the other end. A recess is fitted to the base shaft and includes a locking piece connected to the base shaft by a connecting means.

(2) In the above item (1), the base shaft and the locking piece are connected so that the direction of the base shaft matches the direction of the locking piece.

(3) In the above item (1), the direction of the base shaft and the direction of the locking piece intersect to connect the base shaft and the locking piece.

(4) In the above item (1) or (2), the receiving portion is formed with an elastic locking piece with which the projection is engaged, and the elastic portion at the fitting portion between the base shaft and the concave portion of the locking piece is formed. The dimensions of the side parallel to the edge of the protruding piece engaging with the locking piece and the other side are made different.

(5) In any one of the above items (1) to (4), the connecting means is a male screw, a male screw through hole is formed in the locking piece, and a screw hole is formed in the base shaft.

(6) In the above item (5), the base shaft has a cylindrical portion having a screw hole in the center, and the base shaft is provided on both sides of the cylindrical portion.
The pair of flat plates are formed by a pair of flat plates, and the pair of flat plates are fitted into the recesses of the locking pieces in a close contact state.

[0013]

Embodiments of the present invention will be described below with reference to the accompanying drawings. The chair shell structure shown in FIGS. 1 to 4 basically has a backrest cushion body on the front surface.
It has a middle shell (2) provided with (1), and an outer shell (3) covering the rear surface of the middle shell (2).

Both shells (2) and (3) are synthetic resin molded articles made of a hard elastic material, and have substantially L-shaped side faces. At the front of the outer shell (3) is formed a pair of left and right pivoting pieces (4) which are pivotally attached to the legs of the chair or the lower surface of the seat.

The two shells (2) and (3) are slightly different in the structure of upper and lower shells provided on the outer shell (3) at four receiving portions (5) formed at the four corners of the middle shell (2). The two upper and lower locking means (6), (6), (7) and (7) are connected to each other by being locked.

Referring to FIGS. 1 to 3, both shells (2) and (3)
The coupling structure between the upper receiving portion (5) and the locking means (6) will be described. The receiving portion (5) is formed as a horizontally long rectangular hole, and has a pair of left and right elastic locking portions formed at its left and right side edges with mutually opposing distal ends bent in a U-shape in plan view. Pieces (8) are provided in series. This elastic locking piece
The tip of (8) is adapted to be locked to a protruding piece (10) of a locking piece (9) described later.

The locking means (6) is integrally formed with the outer shell (3) and is engaged with the main shaft (11) by a male screw (12) which is a connecting means. A stop piece (9) is provided. The coupling means includes a tapping screw, an adhesive and the like in addition to the male screw (12).

The base shaft (11) has a prism base (13) and a screw hole (14).
And a pair of left and right flat plates (16) formed on both sides of the cylindrical portion (15). Column (1
The distal end of (5) projects slightly forward from the distal end (16a) of the flat plate (16), and the distal end face (1) of a square hole-shaped recess (17) of a locking piece (9) described later.
7a).

The magnitude relationship between the vertical width (L1) of the prism base (13), the vertical width (L2) of the flat plate (16), and the distance (L3) between the outer surfaces of the pair of flat plates (16) is as follows. The relationship (L1)>(L2)> (L3) holds, and the prism base (13) is formed in a rectangular shape when viewed from the front. A step (18) for receiving the locking piece (9) is formed at the boundary between the prism base (13) and the flat plate (16).

The locking piece (9) of the locking means (6) has a square hole-shaped recess (17) for receiving a pair of left and right flat plates (16) in close contact with each other.
A pair of left and right protruding pieces (10) protruding from the left and right sides of the tip (9a) of the locking piece (9), and a male screw (1
2) is provided with a male screw through-hole (19) that penetrates.

The length (L4) in the vertical direction of the concave portion (17) facing in the same direction as the side edge of the protruding piece (10) of the locking piece (9) is the other side, that is, the side in the horizontal direction. It is set larger than the length (L5). That is, the concave portion (17) is a bottomed hole having a rectangular cross section that is long in the vertical direction.

In such a configuration, the concave portion (17) of the locking piece (9) is fitted to the base shaft (11), and the male screw (12) is made to pass through the male screw through hole (19). By screwing the locking piece (14), the locking piece (9) is screwed to the base shaft (11).

The recess (17) is formed in the shape of a rectangular hole, and the vertical and horizontal dimensions of the fitting portion on the base shaft (11) side into which the recess (17) is fitted are different from each other. If the edge of (10) is not turned in the vertical direction, the locking piece (9) cannot be fitted to the base shaft (11). Therefore, the direction of the locking piece (9) is regulated, and the protruding piece (10) is directed to the direction in which the projection piece (10) is always locked to the pair of left and right elastic locking pieces (8).

In this way, as shown in FIG. 2, when the locking means (6) is inserted into the receiving portion (5), the elastic locking piece (8) of the receiving portion (5) and the protruding piece (10). Are engaged with each other and the locking means
(6) is prevented from coming off, and the middle shell (2) and the outer shell (3) are joined.

Next, based on FIG. 4, both shells (2) and (3)
Receiving part (5) formed near both corners of the lower part of the car and locking means
(7) will be described. The receiving part (5) and the locking means (7)
Since the outer shell (3) is provided near the curved portion of both shells (2) and (3) and the radius of curvature of the outer shell (3) is smaller than the radius of curvature of the middle shell (2), the base shaft of the locking means (7) (20) faces forward,
The receiving part (5) is formed substantially horizontally, and the locking piece (21) faces upward.

The shape of the receiving portion (5) is the same as the shape of the receiving portion (5).
Detailed description is omitted.

A recess (22) is provided at the lower end of the locking piece (21) so as to open rearward and downward, and a male screw through hole is provided.
(23) is formed on the front wall of the locking piece (21) in the front-rear direction. A flange-shaped protruding piece (10) is provided on the upper edge of the locking piece (21) so as to protrude in the left-right direction.

The pair of left and right flat plates (24) of the base shaft (20) are formed only above the column (15) so as not to contact the outer shell (3).

Also in this locking means (7), after the locking piece (21) is attached to the base shaft (20) from the front, the male screw (12) is passed through the male screw through hole (23), and the screw of the base shaft (20) is screwed. By screwing into the hole (14), the base shaft (20) and the locking piece (21) can be screwed. After that, the locking means (7) is inserted into the receiving part (5), and the protruding piece (10) is locked on the elastic locking piece (8), so that the middle shell (2) and the outer shell (3) are connected. Are joined together.

FIG. 5 shows an embodiment in which the present invention is applied to a shell structure of a chair seat. This seat has a middle shell (26) provided with a seat cushion body (25) on the upper surface. )
And an outer shell (27) covering the lower surface of the middle shell (26).

At the four corners of the middle shell (26) and the outer shell (27), receiving parts (5) which are the same as those shown in FIGS. 6) is provided,
By engaging it with each other, both shells (26) (27)
Are connected to each other up and down.

According to the above-described shell structure of the present invention, the base shaft and the receiving portion can be formed in a shape that can be easily removed from the mold, and both shells can be divided into two in the thickness direction of each shell. Can be molded.

As a shell structure of another embodiment, although not shown, the receiving portion may be formed on the outer shell and the locking means may be formed on the middle shell.

[0034]

According to the first aspect of the present invention, the locking piece having the projecting piece is formed separately from the shell and then integrated with the base shaft by the connecting means, so that the base shaft can be easily removed from the mold. And both shells can be manufactured with a simple two-part mold, and the mold cost can be reduced.

Further, unlike the related art, it is not necessary to provide an undercut portion or the like in one shell, so that it is not necessary to forcibly remove the mold from the shell after molding, thereby improving the durability of the mold. And molding defects can be reduced.

According to the second aspect of the present invention, the locking means can be protruded substantially at right angles to the shell, which is optimal for connecting mutually parallel shells.

According to the third aspect of the present invention, the locking means can be provided to be inclined with respect to the shell, and is optimally used for connecting a bent portion or a non-parallel portion between the middle shell and the outer shell.

According to the fourth aspect of the present invention, it is possible to eliminate the possibility that the locking piece is attached to the base shaft in a wrong direction, and the projection can be securely locked to the elastic locking piece.

According to the fifth aspect of the present invention, the locking piece can be easily and reliably provided on the base shaft by the male screw.

According to the sixth aspect of the present invention, since the cylindrical portion is formed, the stress when the male screw is screwed into the female screw can be evenly dispersed. In addition, the combination of the cylindrical portion and the flat plate can reduce the cross-sectional area of the locking means, and can prevent the occurrence of dents (sinks) on the rear surface of the shell during molding.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a middle shell and an outer shell of an embodiment in which the present invention is applied to a backrest of a chair.

FIG. 2 is an enlarged exploded perspective view of an upper coupling portion.

FIG. 3 is a cross-sectional plan view of the same part as in FIG. 2 in a connected state.

FIG. 4 is an enlarged exploded perspective view of the lower connecting portion.

FIG. 5 is a longitudinal sectional front view of a main part of an embodiment in which the present invention is applied to a chair seat.

[Explanation of symbols]

 (1) cushion body (2) middle shell (3) outer shell (4) pivot piece (5) receiving part (6) locking means (7) locking means (8) elastic locking piece (9) locking Block (10) Protrusion (11) Main shaft (12) Male screw (coupling means) (13) Square prism base (14) Screw hole (15) Cylinder (16) Flat plate (16a) Tip (17) Recess (17a) Back end face (18) Step (19) Male screw through hole (20) Main shaft (21) Locking piece (22) Square recess (23) Male screw through hole (24) Flat plate (25) Cushion body (26) Middle shell (27) Outer shell

Claims (6)

[Claims] An engaging means provided on one shell of a middle shell provided with a cushion body on one side surface and an outer shell covering the other side surface of the middle shell has a receiving member formed on the other shell. In the chair shell structure in which the two shells are connected to each other by locking the shell, the locking means engages the base shaft protruding from the one shell and the receiving portion at one end. A flange-shaped protruding piece is formed, and a recess formed at the other end is fitted to the base shaft, and is provided with a locking piece connected to the base shaft by a connecting means. Shell structure for chair. 2. The chair shell structure according to claim 1, wherein the base shaft and the locking piece are connected so that the direction of the base shaft matches the direction of the locking piece. 3. The chair shell structure according to claim 1, wherein the direction of the base shaft and the direction of the locking piece intersect to connect the base shaft and the locking piece. 4. An elastic locking piece with which a projection engages with a receiving portion, and an edge of the projection which engages with the elastic locking piece at a fitting portion between a base shaft and a recess of the locking piece. The chair shell structure according to claim 1 or 2, wherein dimensions of the parallel side and the other side are different. 5. The connecting means is a male screw, a male screw through hole is formed in the locking piece, and a screw hole is formed in the base shaft.
5. The shell structure for a chair according to any one of 4. 6. The base shaft is formed by a cylindrical portion having a screw hole in the center and a pair of flat plates continuously provided on both sides of the cylindrical portion, and the pair of flat plates is in close contact with the concave portion of the locking piece. The shell structure for a chair according to claim 5, wherein the shell structure is fitted.