U.S. Patent Specifications Available to Purchase

A throttle‐controlled, propeller‐driving, gas turbine engine, for an aircraft, including a pitch‐change mechanism connected to vary the pitch of a variable pitch propeller, pitch coarsening and fining passages connected with said mechanism, a valve through which operating fluid under pressure can be selectively supplied to said passages, said valve connected to be movable by a governor mechanism for selecting the passage to be supplied, and additional means which is connected to be actuated by the throttle and which selectively supplies fluid under pressure directly to said passages in a position intermediate said mechanism and said valve in such a manner that the propeller will very quickly absorb the change in the power developed by the engine resulting from movement of the throttle while keeping the engine speed at a constant predetermined value, at which latter it is always maintained by said governor mechanism for any setting of the throttle within the normal operating power range of the engine, said additional means including for the purpose a metering device having a cylinder with a sliding and rolling piston therein, a valve with two relatively rotatable parts for selectively controlling the connexion of a source of fluid pressure cither to one operative end of said cylinder or to said pitch fining passage, a connexion between the other operative end of said cylinder and said pitch coarsening passage, a mechanical connexion between one of said valve parts and said piston whereby said valve part is rotated by movement of said piston, and a mechanical connexion between the other of said valve parts and the throttle whereby movement of the latter will rotate the said other of said valve parts, such that when the throttle‐actuated valve part is moved from the neutral position said piston will be operated by the pressure difference applied to it to effect a follow up movement of the piston‐connected valve part to return the valve to the neutral position.