Solenoid operated valves

Claim 1

In a reciprocating control valve having: a valve body provided with an elongated bore therein and a plurality of spaced ports therealong intersecting said bore, an elongated plunger reciprocably received within said bore, said plunger including spaced hollow portions therewithin having radial ports extending therefrom for controlling flow of fluid between said valve body ports, an electric solenoid of commercially available manufacture cooperatively associated with said plunger for effecting lifting movement thereof in controlling fluid flow, and, a plurality of seals carried by said body encircling said bore and in sealing contact with said plunger to prevent fluid flow through said bore other than through said ported plunger; the improvement therein to reduce to a minimum the required breakaway pressure to initiate movement of said plunger from a stationary condition and require minimum pressure in axially shifting the same, comprising: said plunger having a buffed, chrome-plated exterior surface to provide maximum smoothness of surface, said plunger having a diameter less than three-eighths of an inch (3/8") thereby to minimize the total surface area subject to sliding friction, said seals being formed from extremely low-friction material such as polytetrafluoroethylene, and said seals further having a generally C-shaped cross-section and opening axially of the valve body, with said seals having curved lips thereby to dispose a single lip of said seal in substantially line contact with said plunger and thereby as a valve port of said plunger passes thereunder, fluid in said plunger exerts pressure outwardly against said lip flexing the same to eliminate frictional contact therewith, whereby friction throughout said valve body and valve plunger contact zones are maximally reduced for easy operation of the valve.