Patent ID: 8104711
Filing Date: 2012-01-31
Classification: B64C

Abstract:
1. An auxiliary actuator mechanism for semi-levered landing gear of an aircraft having a main shock absorber strut with upper and lower telescoping portions, with the upper portion connectable to the airframe, and a bogie beam extending fore and aft of the aircraft fuselage with at least one forward axle and wheel and one aft axle and wheel, and a main pivot between the forward and aft axle pivotally connected to the lower portion of the main shock absorber strut, the auxiliary actuator comprising a two stage telescopic hydraulic unit comprising an outer casing with a first stage piston and cylinder actuator having a first piston rod and a second stage piston and cylinder actuator having a second piston rod, the first and second stage actuators operating coaxially within the outer casing, one of the first and second stage actuators being pivotally connectable via an upper connector to the upper portion of the main shock absorber strut, and the other being pivotally connectable via a lower connector to the bogie beam at an auxiliary pivot; wherein the first stage actuator is adapted to dampen pivoting movements of the bogie beam about the main pivot and is operable to an extended position and the second stage actuator is operable between a retracted position and an extended position defined by respective end stops within the outer casing and serves to control the tilt position of the bogie beam relative to the main shock absorber strut, the second stage actuator, when in the retracted position with the first stage actuator in the extended position, limiting the length of the auxiliary actuator between the upper and lower connectors so as to assume a predetermined intermediate length in which the bogie beam is restrained to tilt about the auxiliary pivot and the landing gear is lengthened during take-off of the aircraft, and the second stage actuator, when in the extended position with the first stage actuator in the extended position, allowing the length of the auxiliary actuator between the upper and lower connectors to assume a predetermined maximum length in which the bogie beam is tilted about the main pivot to a stowing position for stowing the landing gear in the aircraft, wherein at least some of the piston rod of each of the first and second actuators extends out of the outer casing when in the extended position, and wherein movement of the second stage actuator from the retracted to the extended position causes pivoting of the bogie beam.