GB2281049A

GB2281049A - Manufacture of foamed seat pads

Info

Publication number: GB2281049A
Application number: GB9316959A
Authority: GB
Inventors: Neil Kevin Carter
Original assignee: Ford Motor Co
Current assignee: Ford Motor Co
Priority date: 1993-08-14
Filing date: 1993-08-14
Publication date: 1995-02-22
Also published as: GB9316959D0

Abstract

Foamed seat pads are manufactured in a female mould 10 by using vacuum applied through a chamber 18 and a series of holes 20 (Fig 1, not shown) in the mould wall to draw a fabric seat covering layer 22 into contact with the mould inner wall closing the mould with a fabric clamping ring 14 (Fig not shown) and a lid 16 and then introducing a foam 26 which fills the internal space in the mould. The clamping ring 14 has vent apertures 25 along one edge where the covering layer extends outside the closed mould, and the mould is arranged so that this edge is uppermost as the foaming reaction takes place. Any foam which escapes from the mould through the vent will then be trimmed off when the covering layer 22 is trimmed. <IMAGE>

Description

Manufacture of foamed seat pads This invention relates to the manufacture of foamed seat pads, ie seat cushions or seat backrest pads or squabs, and in particular to the manufacture of pads made of polyurethane foam.

It is known to manufacture foamed seat pads in a female mould. A sheet of impervious fabric is introduced into the mould cavity to form the seat cavity, and vacuum is used to hold the seat cover in place against the cavity wall. An in situ foaming process is then used to fill the mould cavity behind the cover with a foam which adheres to the back surface of the cover. A lid is applied to the mould whilst the foaming reaction takes place. A process of this type is disclosed in GB-PS 1 325 622.

As the foaming reaction proceeds, gas is vented from the mould through vent holes provided for this purpose.

Together with the gas, some foam also leaves the mould through the vent holes, and this surplus foam has to be removed from the pad before the pad is ready for use.

According to the present invention, there is provided a method of manufacturing a foamed seat pad comprising the steps of placing a sheet of impervious seat cover material in the cavity of a female mould so that the sheet extends beyond edges of the mould, pouring foam-forming liquids into the cavity and arranging the mould so that the mould is vented along a mould edge at the uppermost part of the mould where the sheet of seat cover material extends beyond the mould edge.

In this way, any foam which exits the mould through the vent holes will lie adjacent the free edge of the seat cover material. When the seat cover material is trimmed in the normal way, the excess foam will be automatically removed as part of the one trimming operation.

It is preferred if the mould is filled with the foam-forming liquids and the lid is put in place whilst the mould is in a generally horizontal position. The mould can then be tilted as soon as the lid is in place to raise one edge of the mould (which is provided with vents and from which cover material extends) to an uppermost position.

The invention will now be further described, by way of example, with reference to the accompanying drawing in which Figures 1 to 7 show sequential operating steps in the process according to the invention.

Figure 1 shows a mould with a mould cavity 12, a cloth clamping ring 14 and a lid 16 in exploded view. At the bottom of the mould cavity there is a vacuum chamber 18 which communicates with the cavity through apertures 20.

A piece of cloth 22 is clamped to the top of the mould by a cloth clamping ring 24 and then (Figure 3) vacuum is applied to the vacuum chamber 18 to draw the cloth into the cavity so that it lines the cavity. The cloth is treated so that it is substantially impervious. The clamping ring allows the cloth to be drawn into the mould as the vacuum is applied. Edges of the cloth extend outside the mould, as shown at 23.

Next the foam chemicals are poured in the cavity, onto the cloth 22 (Figure 4). The lid 16 is put in place.

Vent channels 25 are provided along one edge of the clamping ring, for the escape of gas at 27 as the foam expands to fill the cavity. Once the lid has been put in place, the entire mould is tilted until the vent channels 25 are uppermost. (see Figure 5).

As the foam expands and gas is driven out through the vent channels 25, some foam will also leave the mould, especially as the mould becomes completely full with foam. This escaping foam will solidify on the outside of the mould, as indicated at 29 in Figure 6, adjacent the edge 23 of the cloth.

Finally, the completed pad is demoulded and the edges 23 of the cover are trimmed off at 31 (Figure 7). This trimming operation also removes the excess foam 29.

Claims

Claim

1. A method of manufacturing a foamed seat pad comprising the steps of placing a sheet of impervious seat cover material in the cavity of a female mould so that the sheet extends beyond edges of the mould, pouring foamforming liquids into the cavity and arranging the mould so that the mould is vented along a mould edge at the uppermost part of the mould where the sheet of seat cover material extends beyond the mould edge.

2. A method as claimed in Claim 1, wherein the mould is filled with the foam-forming liquids and the lid is put in place whilst the mould is in a generally horizontal position and the mould is tilted as soon as the lid is in place to raise one edge of the mould (which is provided with vents and from which cover material extends) to an uppermost position.

3. A method of manufacturing a foamed seat pad substantially as herein described with reference to the accompanying drawing.