| 摘要 |
<p>A check valve (30) provides a one-way fluid passage (38) from without to within a fluid bladder (10) formed by a pair of plastic sheets (16, 18) sealed together about their periphery (20, 21). The check valve (30) is formed by a pair of superimposed films of thermoplastic material (32, 34), generally equal in length, thermally bonded together at predetermined areas (36) to define the fluid passage (38) throughout the length of the valve (30). The inlet end (64) of the valve (30) has a V-shape edge (58) with the apex pointing in a direction opposite the one-way fluid flow. Each of the films (32, 34), adjacent the V-shape edge (58) of inlet end (64), is sealed to one of the outer sheets (16, 18) where the valve (30) enters the bladder (10) by a seal line of similar V-shape. Each of the films (32, 34) has a high-gloss, cohesive inner surface (54) and a matted, non-cohesive outer surface (55). At least one of the films (32, 34) includes, on its inner surface (54), a release material (40) disposed at a location which corresponds to the area at the inlet end (64) of the fluid passage (38) through the peripheral seal (21) of the bladder (10) to prevent the fusing together of the films (32, 34) at that area of the seal (21). The terminal ends (72) of the superimposed films (32, 34) extend in surface-to-surface relation into the bladder (10) to provide a "duck-bill" type check valve (30). <IMAGE></p> |
