Patent · US Expired

Check valve for fluid bladders

US5144708A · kind A · utility

179Cited by
6References
8Claims
0Family size

Assignee

Inventor

Key dates

Filing dateOct 28, 1991
Grant dateSep 8, 1992
Priority date
Expiry dateOct 28, 2011

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T137/7882
  • WIPO fieldOther special machines
  • WIPO sectorMechanical engineering

Abstract

A check valve provides a one-way fluid passage from without to within a fluid bladder formed by a pair of plastic sheets sealed together about their periphery. The check valve is formed by a pair of superimposed films of thermoplastic material, generally equal in length, thermally bonded together at predetermined areas to define the fluid passage throughout the length of the valve. Each of the films, adjacent one end thereof, is sealed to one of the outer sheets where the valve enters the bladder by a seal line of wedge shape. Each of the films has a high-gloss, cohesive inner surface and a matte, non-cohesive, outer surface. At least one of the films includes, on its inner surface, a release material disposed at a location which corresponds to the area at the inlet end of the fluid passage through the peripheral seal of the bladder to prevent the fusing together of the films at that area of the seal. The seal in that area has a V-shape with apex pointing in a direction opposite the one-way fluid flow. The terminal ends of the superimposed films extend in surface-to-surface relation into the bladder to provide a "duck-bill" type check valve.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.