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An actuator particularly adapted to control a plurality of bleed air valves of a gas turbine engine is disclosed. The actuator comprises n solenoid pilot valves where 2n is the number of actuation positions and 2n-1 is the number of bleed air valves to be actuated. The actuator receives as n bit dig

An actuator particularly adapted to control a plurality of bleed air valves of a gas turbine engine is disclosed. The actuator comprises n solenoid pilot valves where 2n is the number of actuation positions and 2n-1 is the number of bleed air valves to be actuated. The actuator receives as n bit digital signal corresponding to the number of bleed air valves to be actuated for a particular operating condition of the engine and the actuator converts this number into a correct mechanical position. The conversion is accomplished by a series of telescoping cylinder and piston assemblies each having an expandable chamber. Each chamber is independently contracted or expanded by an associated pilot valve controlling a pressure source in response to the presence or absence of a particular bit in the digital word. The size of the expandable chamber of each assembly is related to the others by ascending powerts of two and correspond to a bit position in the digital input signal.

대표청구항 ▼

A multiposition actuator for changing a N-bit digital word into N physical positions of an actuator element comprising: N-1 telescoped open ended cylinders mounted in an open ended bore with the open ends of said cylinders disposed toward the closed end of said bore and an end cap closing the open e

A multiposition actuator for changing a N-bit digital word into N physical positions of an actuator element comprising: N-1 telescoped open ended cylinders mounted in an open ended bore with the open ends of said cylinders disposed toward the closed end of said bore and an end cap closing the open end of said bore; said actuator element including an elongated body passing through an aperture in the closed end of said bore and having a flange being a double acting piston disposed within the innermost cylinder; said actuator element, cylinders and end cap forming N piston cylinder combinations wherein the piston area of each successive piston increases from the innermost combination to the outermost combination, and wherein the flange piston area disposed toward the closed end of the bore is less than the flange piston area for the innermost cylinder; each of said combinations operable to move said actuator element independently of the other combinations through a distance controlled by an expandable chamber disposed between the cylinder and piston of each combination, each distance being related to the other distances by powers of the numeral 2; N pilot solenoids, each associated with an expandable chamber and operable to control means for communicating a source pressure to a corresponding chamber and the source pressure from a corresponding chamber to a reference pressure and each associated with one of the bits of said digital input and actuated by one of the states of said bit; a bias chamber defined by the open ends of said cylinders and the closed end of said bore; means for communicating said source pressure to said bias chamber such that movement of the expandable chambers is accomplished by the force difference between the pistons because of the source and reference pressures acting over the differing piston areas.