GB2216842A

GB2216842A - Mold steel for foamed plastic molding

Info

Publication number: GB2216842A
Application number: GB8906931A
Authority: GB
Inventors: Hisayoshi Mizuno; Ichiro Matsuura; Kiichiro Ishimaru; Fumio Saotome; Yoichi Omata
Original assignee: Ikeda Bussan Co Ltd
Current assignee: Ikeda Corp
Priority date: 1988-03-26
Filing date: 1989-03-28
Publication date: 1989-10-18
Also published as: JPH01148313U; GB8906931D0; JPH0538899Y2

Abstract

A mold steel (10) for foamed plastic molding to be utilized in foamed plastic pad member formation and the simultaneous combining of the skin cover member and the pad member capable of coping with a partial change in the shape of the pad member in a simple and inexpensive manner. The mold steel includes a lower mold steel (11) with a molding surface made up by top surfaces of a plurality of blocks (15). <IMAGE>

Description

MOLD STEEL FOR FOAMED PLASTIC MOLDING BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a mold steel for foamed plastic molding suitable for molding foamed plastic article such as to be used for car seat cushions and seat backs in conjunction with skin covers.

Description of the Background Art The car seat cushions and car seat backs usually comprises a pad member made of such material as a soft polyurethane, and a skin cover member to be wrapped around the pad member. One of the popular and efficient method of manufacturing such a car seat cushion is to use a pair of mold steels. An example of such mold steel is shown in Fig. 1 where there is provided a pair of mold steels comprising a lower mold steel 1 and an upper mold steel 2.

A sack-shaped skin cover member 3 prepared by sewing process is place on top of a inner surface of the lower mold steel 1 over which liquid soft polyurethane is poured in, and with the upper mold steel 2 placed on top of the lower mold steel 1 the liquid soft polyurethane is foamed and stiffened to become the pad member 4 and at the same time combining of the skin cover member 3 and the pad member 4 is achieved.

However, in a situation such as that in which only side support portions of the car seat cushion are to be slightly modified, a whole lower mold steel 1 has to be replaced by a new one with the desired shape despite of the fact that only a part of the lower mold steel 1 is actually altered, which contributes to an increase in manufacturing cost.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a mold steel for foamed plastic molding to be utilized in foamed plastic pad member formation and the simultaneous combining of the skin cover member and the pad member capable of coping with a partial change in the shape of the pad member in a simple and inexpensive manner.

This object of the present invention is achieved by providing a mold steel for foamed plastic molding to be utilized in foamed plastic pad member formation and the simultaneous combining of the skin cover member and the pad member, comprising: a lower mold steel including: an outer frame with a cavity portion; and a plurality of blocks to be installed into the cavity portion whose top surfaces form a molding surface of the lower mold steel over which the skin cover member and the pad member are to be placed; and an upper mold steel which open and close over the outer frame of the lower mold steel with the skin cover member and the pad member inside the cavity portion.

Other features and the advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a cross sectional view of a conventional mold steel for foamed plastic molding.

Fig. 2 is a perspective view of one embodiment of a mold steel for foamed plastic molding according to the present invention.

Fig. 3(A) and (B) are cross sectional views of the mold steel of Fig. 2 for explaining a situation where this mold steel of the present invention is advantageous.

Fig. 4 is a cross sectional view of the mold steel of Fig. 2 for explaining a step of molding process using this mold steel of the present invention.

Fig. 5 is a cross sectional view of the mold steel of Fig. 2 for explaining another step of molding process using this mold steel of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to Fig. 2, there is shown one embodiment of the mold steel for foamed plastic molding according to the present invention.

This mold steel 10 for foamed plastic molding comprises a lower mold steel 11 and an upper mold steel 12.

The lower mold steel 11 further comprises a case-like outer frame 14 having a cavity portion 13, and a plurality of blocks 15 to be installed in the cavity portion 13. The upper mold case 12 is pivotally connected to the outer frame 14 of the lower mold steel 11 by hinges 16a and 16b so as to facilitate the opening and closing of the upper mold steel 12 against the lower mold steel 11.

In this embodiment of Fig. 2, the cavity portion 13 of the lower mold steel 11 is divided into a plurality of regions defined in terms of approximately 100 mm wide intervals in both longitudinal and transversal directions, such that each of the plurality of blocks 15 can be installed into each of the plurality of regions in the cavity portion 13.

Each of the plurality of blocks 15 has a top surface in such a shape that top surfaces of the blocks to be adjacently installed such as 151s and 1512 or 153o and 1541 in Fig. 2 can form a piece-wise smooth and continuous molding surface of the lower mold steel 11.

Now, in a situation such as that shown in Figs. 3(A) and 3(B) in which only side support portions of the car seat cushion are to be slightly modified so that the lower mold steel have to be changed from the lower mold steel 11 with the plurality of blocks 15 shown in Fig. 3(A) to the new lower mold steel 11' with the plurality of new blocks 15' shown in Fig. 3(B), it is only necessary to replace the blocks 15tut, 1521. 1571, and 158t by the new blocks 15'tut, 15'21 , 15'71 , and 17'sir in this embodiment because of the configuration of the lower mold steel made by the plurality of blocks 15, unlike the conventional mold steel for which a whole lower mold steel had to be replaced by a new one.

Consequently, cost for manufacturing the mold steel can be greatly reduced, and also by preparing number of blocks with various different shapes, the efficiency in manufacturing the car seat cushion can be improved.

Next, the molding process for manufacturing the car seat cushion with this mold steel 10 will be explained with references to Figs. 4 and 5.

First, as showun in Fig. 4, a skin cover 17 is placed on top of the molding surface of the lower mold steel 11 formed by the top surfaces of the plurality of blocks 15.

This skin cover 17 comprises a cover 18 made of such material as vinylchloride with a back portion (wadding) 19 made of such material as slab urethane incorporated, and is prepared in a sack-like shape of the seat cushion beforehand by a sewing process.

Then, the liquid polyurethane 20 is poured over the skin cover 17 from a nozzle 21.

Next, as shown in Fig. 5, the upper mold steel 12 is closed over the lower mold steel 11, and the the liquid polyurethane is foamed and stiffened to become the pad 22 and at the same time combining of the skin cover 17 and the pad 22 is achieved.

After the formation of the pad 22 is completed, the upper mold steel 12 is opened, and the seat cushion made of the skin cover 17 and the pad 22 combined is taken out from the lower mold steel 11.

The seat cushion manufactured in this manner has precisely the same form as those manufactured with a conventional mold steel. The divided configuration of the the plurality of blocks 15 does not affect the output seat cushion because of the presence of the skin cover 17.

As explained, according to the present invention it is possible to provide a mold steel for foamed plastic molding to be utilized in foamed plastic pad member formation and the simultaneous combining of the skin cover member and the pad member capable of coping with a partial change in the shape of the pad member in a simple and inexpensive manner.

It is to be noted that the manner of dividing the plurality of blocks 15 in the above embodiment can be modified in any desirable manner. For example, dividing the plurality of blocks 15 into just two side support portions and one back portion may also be sufficiently effective.

Also it should be noted that the mold member is not necessarily made of steel, but may be made of material such as wood, ceramics and the like.

Besides this, many modifications and variations of the above embodiment may be made without departing from the novel and advantageous feature of the present invention.

Accordingly, all such modifications and variations are intended to be included within the scope of the appended claims.

Claims

WHAT IS CLAIMED IS:

1. A mold steel for foamed plastic molding to be utilized in foamed plastic pad member formation and the simultaneous combining of the skin cover member and the pad member, comprising: a lower mold steel including: an outer frame with a cavity portion; and a plurality of blocks to be installed into the cavity portion whose top surfaces form a molding surface of the lower mold steel over which the skin cover member and the pad member are to be placed; and an upper mold steel which open and close over the outer frame of the lower mold steel with the skin cover member and the pad member inside the cavity portion.

2. The mold steel of claim 1, wherein the molding surface of the lower mold steel is piece-wise smooth and continuous.

3. The mold steel of claim 1, wherein the cavity portion is divided up into a plurality of regions for receiving the plurality of blocks.

4. The mold steel of claim 1, wherein at least one block among the plurality of blocks is provided for each part of the skin cover member and the pad member combination with distinguishable shape.

5. The mold steel of claim 1, wherein the mold steel is used for forming car seat cushions t car seat backs.

6. A mold comprising a frame defining a cavity and at least one molding block, receivable within the cavity, the at least one molding block having at least one surface which, in use, acts as a molding surface.

7. A method of molding an article using a mold according to any one of Claims 1 to 6.

8. A mold substantially as hereinbefore described with reference to, and as shown in, Figures 2 to 5 of the accompanying drawings.

9. A method of molding an article substantially as hereinbefore described with reference to Figures 4 and 5 of the accompanying drawings.

10. Any novel feature or combination of features disclosed herein.