Abstract: A method for fabricating protective seals or "boots" for electric switches, such as push button and toggle switches, is described. In place of traditional rubber molding techniques, the seals are made by thermoforming a plastic film, preferably polyurethane, over a mold containing the nut portion of the seal and pins configured for a suitable shape for toggle or push button switches. Inexpensive stamped, threaded nuts can be employed, and this, together with reduced tooling costs and the efficiency of the method, produce extremely economical electric switch seals. The seals themselves offer unique benefits in that the thin, yet tough, plastic film does not interfere with the functioning of the switches, while providing prolonged service life under difficult conditions. Utilizing clear urethane film, the resultant seals provide clear viewing of the functioning of the switch within.

Abstract: A reliable and economical one way fluid flow check valve fabricated from two thin sheets of plastic is described. One or more half cylindrically shaped depressions are vacuum formed across one or both sheets of plastic, and a 1/2 funnel shape fluid entrance can be simultaneously vacuum formed in one or both sheets. The two sheets are than heat sealed together at their longitudinal edges to form the complete check valve. The check valve is preferably in the form of a truncated V. The check valve can be heat sealed into a variety of devices such as toy balloons, cushions, mattresses, inflatable boats, and the like. Various modifications are described for light or heavier fluid pressure applications.