Fluid energy translating device

Claim 1

In a fluid energy translating device having an expansible chamber for translating fluid under pressure between low and high pressure ports, and in which displacement of the chamber is determined by a control member having a nul position for essentially non-displacement and a second position establishing displacement, means to locate the control member in nul position upon occurrence of excessive pressure or excessive temperature of fluid being translated and comprising: (a) a plunger engaging said control member and operated by fluid under pressure to dispose said control member in nul position; (b) a valve chamber for receiving high pressure fluid translated by said device and a control passage leading therefrom for directing high pressure fluid to the plunger; (c) a valve in said chamber for closing and disclosing said passage; (d) means applying a bias to said valve normally to locate the valve in closing position in opposition to fluid pressure tending to locate the valve in opening position; (e) a thermal element positioned in a temperature sensing chamber to sense an excessively high operating temperature of fluid being translated and having an extendable portion in alignment with and directly engageable with said valve in opposition to said valve bias means; and (f) passage means for delivering fluid being translated into and out of said temperature sensing chamber.