US 5,144,708 · Granted 1992-09-08
The One-Way Valve That Keeps Inflatable Furniture From Deflating
Imagine a water balloon with a tiny valve built right into the plastic seam—that's what this patent does. Two thin plastic films are fused together with a clever gap that lets air or water flow in one direction only, like a duck's bill that closes when you try to push backward. It's the invisible gatekeeper for any inflatable product.
The plain-English version
What it protects
The claim covers a check valve made from two bonded plastic films with a V-shaped inlet seal and a duck-bill outlet that allows fluid to enter a plastic bladder but prevents it from leaking back out. What's protected is the specific arrangement: high-gloss inner surfaces bonded at precise zones, matte outer surfaces for non-stick properties, release material placed to prevent the valve from sealing shut, and the terminal film ends extending into the bladder to create the one-way flap mechanism.
Why it matters
This patent solves a real manufacturing problem for inflatable products like airbeds, pool floats, and inflatable furniture—getting air or water in without it leaking back out during storage or use. By embedding the check valve directly into the seam during manufacturing, rather than using a separate mechanical valve, the design is cheaper to produce, more durable, and creates a cleaner product. The thermally bonded plastic approach was an efficient way to make disposable inflatables reliable.
Real-world use
Every time you inflate an air mattress or pool float and it stays firm overnight, that one-way valve in the seam is silently doing its job, keeping the air trapped inside while letting you pump more in.
Original USPTO 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.
Patent details
- Publication number
- US 5,144,708
- Filing date
- 1991-10-28
- Grant date
- 1992-09-08
- Assignee
- Dielectrics Industries
- Inventor(s)
- PEKAR; ROBERT W.
- CPC class
- F16K15/00
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