GB1577624A

GB1577624A - Seat cushion

Info

Publication number: GB1577624A
Application number: GB1373177A
Authority: GB
Original assignee: Tachikawa Spring Co Ltd
Current assignee: Tachi S Co Ltd
Priority date: 1976-04-05
Filing date: 1977-03-31
Publication date: 1980-10-29
Also published as: SE7703916L; JPS52132704U; FR2347009A1; IT1115286B; DE2715027C3; AU496835B1; AU2397877A; FR2347009B1; DE2715027B2; SE431932B; DE2715027A1

Description

(54) SEAT CUSHION (71) We, TACHIKAWA SPRING COMPANY LIMITED, a Japanese company, of 3-2-12, Matsubara-cho, Akishima, Tokyo, Japan, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to a seat cushion which is comfortable to sit on and which is satisfactorily permeable to air, particularly for use in vehicles.

A seat covering of fabric material with or without a vinyl-resin-coating is used in many cases for seat cushions in automobiles.

The seat cushion of this kind generally comprises a filter pad of cushiony material such as foamed polyurethane packed in a bag-like structure prepared by sewing together a plurality of pieces of vinyl-resincoated or non-vinyl-resin-coated fabric material cut to conform to the desired configuration of the seat cushion, and the baglike structure containing the filler pad therein is mounted on a frame provided with springs. However, such a conventional seat cushion requires much time and labour for its manufacture. In addition, twists and creases impairing the appearance of the product frequently occur, and the remedy thereof also requires much time and labour.

In an effort to obviate these defects, various methods have been proposed hitherto in which a seat covering of vinyl-resincoated fabric material is shaped into a baglike structure by any suitable means including heat forming and vacuum forming, and a filler pad of cushiony material is inserted into the bag-like structure thus prepared, or, in lieu of the insertion, a filler pad of cushiony material is molded together with such a bag-like structure by a molding process.

However, the technique of heat forming or vacuum forming is applicable only to a fabric material having a vinyl-resin-coating or backing. Further, in the case of the molding process, the polyurethane foaming agent may penetrate into the texture of the fabric material tending to harden the seat covering, or it may be non-uniformly distributed and solidify on the surface of the seat covering to spoil the appearance of the seat cushion. Thus, the prior art proposals have been defective in that the seat covering is not satisfactorily permeable to air and the appearance of the seat cushion can be spoilt, and the comfort of the seat cushion is also degraded.The prior art proposals have also been defective in that the mold releasing agent used in the molding step tends to produce a skin layer or a thin impermeable surface layer on the surface of the filler pad of foamed polyurethane, and this impermeable surface layer tends to be stripped when the filler pad of foamed polyurethane is bonded to the seat covering.

According to the present invention there is provided a seat cushion comprising: a preformed seat covering of air-permeable fabric material bearing an embossed pattern or patterns similar to a pattern or patterns appearing on a product fabricated with a sewing machine; a filler pad comprising a first portion, adjacent to a seat portion of the seat covering, of relatively low density foamed synthetic resin material and a second portion on that side of the first portion opposite to the seat portion of the seat covering, of relatively high density foamed synthetic resin material similar to that of the first portion; and a frame provided with springs, the seat covering with the filler pad therein being mounted on the frame, wherein (i) at least that surface of the filler pad adjacent to the seat portion is formed by cutting the foamed synthetic resin material or (ii) the first portion at least of the filler pad is foamed in situ within the seat covering, so as to provide the filler pad with a permeable surface adjacent to the seat portion of the seat covering.

Our co-pending Application No.

13732/77 (Serial No. 1 577 571) relates to a method of manufacturing a molded seat cushion in which a permeable fabric seat covering material free from resin is placed between upper and lower dies, treated with steam, and molded to form a seat covering of bag-like structure. The structure is filled with two filler pads, the first of which is less dense than the second, and is mounted on a spring frame by anchoring the peripheral edges of the seat covering to the frame.

For a better understanding of the present invention and to show more clearly how it may be carried into effect reference will now be made, by way of example, to the accompanying drawings, in which: Fig. 1 is a schematic sectional view of one embodiment of a seat cushion according to the present invention Fig. 2a is a schematic sectional view of a modification of a second filler pad of the seat cushion, which second filler pad is obtained by profile cutting a slab of foamed material; and Fig. 2b is a schematic sectional view of a modification of a first filler pad of the seat cushion which is made of similar material to the second filler pad.

Referring to Fig. 1, a seat covering 1 of woven or non woven air-permeable fabric material (such as woven cloth, knitted fabric or non-woven cloth) is shaped into a bag-like structure by the steps of placing the fabric material on a lower die disposed opposite to an upper die in a press, and, while supplying fluid such as steam at a high temperature into the forming cavity by way of a steam supply pipe to heat and wet the fabric material, urging the upper and lower dies relative to each other to press the fabric material into the desired shape between the dies in the presence of high-temperature steam. A first filler pad 2 formed from a foamed material such as foamed polyurethane or foamed vinyl resin, is bonded to the seat covering 1 thus obtained, and then, a second filler nad 3 formed from similar material is bonded to the first filler pad 2.The fabric material used to provide the seat covering 1 is preferably extensible and may be cut into pieces corresponding to the body and side portions of the seat covering 1 to be then sewn together or may be a single piece corresponding to the final shape of the seat covering 1. Further, stabilizing treatment may be applied to the back face of the fabric material to provide required stability against deformation under heat, or the fabric material itself may be deformable upon application of heat.

The first filler pad 2 is bonded to the seat covering 1 of the bag-like structure while the pressed seat covering 1 is still placed on the lower die, or after it has been transferred to a mold of the same shape.

The second filler pad 3 bonded to the first filler pad 2 has a density greater than that of the latter, or is harder than the latter.

The second filler pad 3 may have a precut shape as shown by 3' in Fig. 2a so that the impermeable surface layer produced by, for example, a mold releasing agent is removed thus improving the permeability to air. Such second filler pad 3' can be easily obtained by profile cutting. The first filler pad 2 may have an original shape as shown by 2' in Fig. 2b also by profile cutting.

Since these filler pads are shaped by cutting, the skin layer or impermeable surface layer formed on the surface of the foamed material can be removed. The seat cushion having the first filler pad 2 incorporated therein can provide comfortableness to sit similar to that of conventional seat cushions manufactured by sewing with a sewing machine.

After bonding the second filler pad 3 to the first filler pad 2, the seat covering 1 containing the first and second filler pads 2 and 3 therein is mounted on a frame 5 provided with springs 4 in a manner as shown in Fig. 1, and is then anchored at its peripheral edge to the frame 5 by means such as clips.

As an alternative to cutting the filler pads, when the fabric material providing the seat covering 1 of the bag-like structure is of fine mesh texture or is impermeable to liquid, the part corresponding to the first filler pad 2 may be formed by direct molding of foamed polyurethane on the seat covering 1 of the bag-like structure. In such a case, no mold releasing agent is required which avoids the formation of an impermeable surface layer, but if necessary a suitable treatment or preventative means may be applied to the surface of the fabric material to prevent penetration of the polyurethane solution. The second filler pad 3 may then be formed by direct molding of foamed polyurethane on the first filler pad 2. That is, two molding steps are taken to provide these parts of the seat cushion.

After bonding the first filler pad 2 to the seat covering of bag-like structure, the second filler pad 3 may be formed by molding the same together with the frame 5 and springs 4. Further, depending on the quality of the fabric material, the first filler pad 2 may be formed by directly molding foamed polyurethane or like material on the seat covering 1 of the bag-like structure, and then the second filler pad 3 may be bonded to the first filler pad 2. The seat covering 1 containing the first and second filler pads 2 and 3 may then be mounted on the frame 5 provided with the springs 4.

The first filler pad 2 may be eliminated, and one surface portion of the second filler pad 3 formed by molding may have a density of less than that of the remaining portion so that, when such surface portion is bonded to the seat covering 1 of bag-like structure, it can exhibit the effect equivalent to that of the first filler pad 2.

Although not shown in Fig. 1, an embossed pattern, and patterns similar to a stitch pattern, a welt pattern and any other patterns appearing on products fabricated by sewing with a sewing machine are provided on the surface of the seat covering 1 so as to provide an external appearance similar or equivalent to that of the sewn product and also to prevent slipping of the body by the embossing. In this case, the concave portions on the inner surface of the seat covering 1 may better be completely filled with the foamed polyurethane providing the first filler pad 2 so as to prevent occurrence of creases in that area.

WHAT WE CLAIM IS: 1. A seat cushion comprising: a preformed seat covering of air-permeable fabric material bearing an embossed pattern or patterns similar to a pattern or patterns appearing on a product fabricated with a sewing machine; a filler pad comprising a first portion, adjacent to a seat portion of the seat covering, of relatively low density foamed synthetic resin material and a second portion, on that side of the first portion opposite to the seat portion of the seat covering, of relatively high density foamed synthetic resin material similar to that of the first portion; and a frame provided with springs, the seat covering with the filler pad therein being mounted on the frame, wherein (i) at least that surface of the filler pad adjacent to the seat portion is formed by cutting the foamed synthetic resin material, or (ii) the first portion at least of the filler pad is foamed in situ within the seat covering, so as to provide the filler pad with a permeable surface adjacent to the seat portion of the seat covering.

2. A seat cushion as claimed in claim 1, wherein the filler pad is formed of foamed polyurethane.

3. A seat cushion as claimed in claim 1, wherein the filler pad is formed of foamed vinyl resin.

4. A seat cushion as claimed in claim 1, 2 or 3, wherein the filler pad comprises two separate pads, one of relatively high density foamed material and the other of relatively low density foamed material.

5. A seat cushion as claimed in claim 4, wherein the pad of relatively low density material is bonded to the seat portion of the seat covering and the pad of relatively high density material is bonded to the pad of relatively low density material.

6. A seat cushion as claimed in claim 4, or 5, wherein both pads are formed by cutting the foamed synthetic resin material.

7. A seat cushion as claimed in claim 4, wherein the pad of relatively low density material is bonded to the seat portion of the seat covering and the pad of relatively high density material is formed by foaming the synthetic resin material within the seat covering.

8. A seat cushion as claimed in claim 7, wherein the pad of relatively high density material is molded together with the frame and the springs.

9. A seat cushion as claimed in claim 4, wherein the pad of relatively low density material is formed by foaming the synthetic resin material in situ within the seat covering and the pad of relatively high density material is formed by foaming the synthetic resin material therefor in situ within the seat covering after the pad of relatively low density has been formed.

10. A seat cushion as claimed in claim 9, wherein the pad of relatively high density material is molded together with the frame and the springs.

11. A seat cushion as claimed in claim 4, wherein the pad of relatively low density material is formed by foaming the synthetic resin material in situ within the seat covering and the pad of relatively high density material is bonded to the pad of relatively low density material.

12. A seat cushion as claimed in claim 11, wherein the pad of relatively high density material is formed by cutting the foamed synthetic resin material.

13. A seat cushion as claimed in claim 9, 10, 11 or 12, wherein the fabric material of the seat covering is treated to prevent the penetration of the synthetic resin

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. then the second filler pad 3 may be bonded to the first filler pad 2. The seat covering 1 containing the first and second filler pads 2 and 3 may then be mounted on the frame 5 provided with the springs 4. The first filler pad 2 may be eliminated, and one surface portion of the second filler pad 3 formed by molding may have a density of less than that of the remaining portion so that, when such surface portion is bonded to the seat covering 1 of bag-like structure, it can exhibit the effect equivalent to that of the first filler pad 2. Although not shown in Fig. 1, an embossed pattern, and patterns similar to a stitch pattern, a welt pattern and any other patterns appearing on products fabricated by sewing with a sewing machine are provided on the surface of the seat covering 1 so as to provide an external appearance similar or equivalent to that of the sewn product and also to prevent slipping of the body by the embossing. In this case, the concave portions on the inner surface of the seat covering 1 may better be completely filled with the foamed polyurethane providing the first filler pad 2 so as to prevent occurrence of creases in that area. WHAT WE CLAIM IS:

1. A seat cushion comprising: a preformed seat covering of air-permeable fabric material bearing an embossed pattern or patterns similar to a pattern or patterns appearing on a product fabricated with a sewing machine; a filler pad comprising a first portion, adjacent to a seat portion of the seat covering, of relatively low density foamed synthetic resin material and a second portion, on that side of the first portion opposite to the seat portion of the seat covering, of relatively high density foamed synthetic resin material similar to that of the first portion; and a frame provided with springs, the seat covering with the filler pad therein being mounted on the frame, wherein (i) at least that surface of the filler pad adjacent to the seat portion is formed by cutting the foamed synthetic resin material, or (ii) the first portion at least of the filler pad is foamed in situ within the seat covering, so as to provide the filler pad with a permeable surface adjacent to the seat portion of the seat covering.

material.

14. A seat cushion as claimed in claim 1, 2 to 3, wherein the filler pad is formed in a single foaming step in which the portions of relatively low density and of relatively high density are formed simultaneously.

15. A seat cushion as claimed in any preceding claim, wherein the seat covering is formed by pressing the fabric material between two dies in the presence of high temperature steam.

16. A seat cushion substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.