Engine, propeller and rotor installations

Claim 2

An engine, propeller and rotor installation including at least one engine-driven propeller and at least one rotor, which separate rotor or rotors in certain modes of operation of the installation can be driven by the engine or engines thereof with the propeller, but in another mode of operation are autorotative, a pitch control mechanism for adjusting the pitch of the propeller blades, coupling means comprising a fluid coupling and a mechanical coupling arranged in parallel between said engine or engines and said propeller whereby when operation of the propeller is not required, the coupling means is disengaged but is such as to permit drive to said rotor or rotors to occur even when the coupling means is disengaged, and a control system for said coupling means, said control system being arranged so that before engagement or disengagement of the mechanical coupling can take place the propeller blades are caused automatically to take up an extreme fine pitch condition, and, simultaneously, hydraulic liquid is introduced to the fluid coupling.

Claim 3

An engine, propeller and rotor installation including at least one engine-driven variable-pitch propeller and at least one rotor, which rotor or rotors in certain modes of operation of the installation can be driven by the engine or engines thereof with the propeller, but in a second mode of operation said rotor or rotors are autorotative independently of said propeller and said engine or engines, a pitch control mechanism for adjusting the pitch of the propeller blades, and coupling means comprising a fluid coupling and a mechanical coupling arranged in parallel betweEn said engine or engines and said propeller.

Claim 4

An engine, propeller and rotor installation including at least one engine-driven variable-pitch propeller and at least one rotor, which rotor or rotors in certain modes of operation of the installation can be driven by the engine or engines thereof with the propeller, but in a second mode of operation said rotor or rotors are autorotative independently of said propeller and said engine or engines, a pitch control mechanism for adjusting the pitch of the propeller blades, and coupling means comprising a fluid coupling and a mechanical coupling arranged in parallel betweEn said engine or engines and said propeller.

Claim 5

The engine, propeller and rotor installation according to claim 2 wherein the rotor or rotors in third modes of operation are driven by the engine or engines thereof when the propeller is stationary.

Claim 6

The engine, propeller and rotor installation according to claim 3 further comprising a control system for the coupling means which is arranged so that before engagement or disengagement of the mechanical coupling can take place, the propeller blades are caused automatically to take up an extreme fine pitch condition, and simultaneously, hydraulic liquid is introduced to the fluid coupling.

Claim 7

An engine, propeller and rotor installation including an engine-driven variable-pitch propeller, and at least one separate rotor, which rotor or rotors in certain modes of operation of the installation can be driven by the engine or engines thereof with the propeller, a pitch control system for adjusting the pitch of the propeller blades in response to input or datum signals and in response to signals themselves responsive to the torque output of the engine or engines, said torque-responsive signals being applied to the system in such manner as, without substantially reducing the power transmitted to the rotor or rotors, to cause such change in propeller blade pitch as will reduce power absorption by the propeller by an amount necessary for the engine or engines to avoid reaching a stalled condition, coupling means comprising a fluid coupling and a mechanical coupling arranged in parallel between said engine or engines and said propeller whereby when operation of the propeller is not required the coupling means is disengaged but is such as to permit drive to said rotor or rotors to occur even when the coupling means is disengaged, and a control system for said coupling means, said control system being arranged so that before engagement of disengagement of the mechanical coupling can take place the propeller blades are caused automatically to take up an extreme fine pitch condition, and, simultaneously, hydraulic liquid is introduced to the fluid coupling.

Claim 8

An engine, propeller and rotor installation including an engine-driven variable-pitch propeller, and at least one separate rotor, which rotor or rotors in certain modes of operation of the installation can be driven by the engine or engines thereof with the propeller, a pitch control system for adjusting the pitch of the propeller blades in response to input or datum signals and in response to signals themselves responsive to the torque output of the engine or engines, said torque-responsive signals being applied to the system in such manner as, without substantially reducing the power transmitted to the rotor or rotors, to cause such change in propeller blade pitch as will reduce power absorption by the propeller by an amount necessary for the engine or engines to avoid reaching a stalled condition, coupling means comprising a fluid coupling and a mechanical coupling arranged in parallel between said engine or engines and said propeller whereby when operation of the propeller is not required the coupling means is disengaged but is such as to permit drive to said rotor or rotors to occur even when the coupling means is disengaged, and a control system for said coupling means, said control system being arranged so that before engagement of disengagement of the mechanical coupling can take place the propeller blades are caused automatically to take up an extreme fine pitch condition, and, simultaneously, hydraulic liquid is introduced to the fluid coupling.

Claim 9

An installation as claimed in claim 5, wherein the means for operating the mechanical coupling comprises an hydraulic actuator.

Claim 10

An installation as claimed in claim 6, wherein a spring-box device is associated with said hydraulic actuator to enable the actuator to be operated before the input and output members of the mechanical coupling are in synchronism.

Claim 11

An installation as claimed in claim 5, wherein automatic means are provided in said system, whereby as soon as engagement or disengagement of the mechanical coupling takes place, the liquid supply to the fluid coupling is cut off.

Claim 12

An installation as claimed in claim 5, and adapted for fitment to an aircraft, wherein one rotor is used for lift of the aircraft from the ground and is driven by the engine or engines of the aircraft while a second rotor, which is continuously driven with the lift rotor, is provided to counteract the torque of the lift rotor.

Claim 13

An engine, propeller and rotor installation including an engine-driven hydraulic variable-pitch propeller, and at least one separate rotor, which rotor or rotors in certain modes of operation of the installation can be driven by the engine or engines thereof with the propeller, an hydraulic manually initiated pitch control system of followup type for adjusting the pitch of the propeller blades in response to input or datum signals and in response to signals themselves responsive to the torque output of the engine or engines, said torque-responsive signals being applied to an input member of an hydraulically operable servomechanism which, upon the attainment of a torque-responsive signal of a predetermined magnitude, effects the superimposing of such adjustment upon the manual input of said pitch control system as, without substantially reducing the power transmitted to the rotor or rotors, to cause such change in propeller blade pitch as will reduce power absorption by the propeller by an amount necessary for the engine or engines to avoid reaching a stalled condition, said pitch control system including an hydraulic valve member, to which said input member is connected through a translation bearing and operating peg assembly associated with slot means formed in the propeller structure, which valve member is housed within the propeller hub and controls the flow of hydraulic liquid to and from a pitch-change motor forming part of the pitch control system, and said input member comprises a valve element capable of directing pressure liquid to one side of the piston of a piston-and-cylinder device coupled directly to said assembly, and said valve element being directly coupled to a bellows assembly, the interior of the bellows of which is subjected to said torque-responsive signals.

Claim 14

An engine, propeller and rotor installation including an engine-driven hydraulic variable-pitch propeller, and at least one separate rotor, which rotor or rotors in certain modes of operation of the installation can be driven by the engine or engines thereof with the propeller, an hydraulic manually initiated pitch control system of followup type for adjusting the pitch of the propeller blades in response to input or datum signals and in response to signals themselves responsive to the torque output of the engine or engines, said torque-responsive signals being applied to an input member of an hydraulically operable servomechanism which, upon the attainment of a torque-responsive signal of a predetermined magnitude, effects the superimposing of such adjustment upon the manual input of said pitch control system as, without substantially reducing the power transmitted to the rotor or rotors, to cause such change in propeller blade pitch as will reduce power absorption by the propeller by an amount necessary for the engine or engines to avoid reaching a stalled condition, said pitch control system including an hydraulic valve member, to which said input member is connected through a translation bearing and operating peg assembly associated with slot means formed in the propeller structure, which valve member is housed within the propeller hub and controls the flow of hydraulic liquid to and from a pitch-change motor forming part of the pitch control system, and said input member comprises a valve element capable of directing pressure liquid to one side of the piston of a piston-and-cylinder device coupled directly to said assembly, and said valve element being directly coupled to a bellows assembly, the interior of the bellows of which is subjected to said torque-responsive signals.

Claim 15

An installation as claimed in claim 10, wherein a further valve element is connected in circuit with said valve element and is operable by engine-speed-sensitive governor means when a predetermined reduction in engine speed is reached, due to excessive or too-rapidly applied torque demands upon the engine or engines, such opening admitting pressure liquid to said first valve element to supplement the force exerted by the torque-responsive signals applied to said bellows and thereby to ensure pitch adjustment for said reduction in power absorption by the propeller.