Patent ID: 6182925
Filing Date: 2001-02-06
Classification: B64C,F15B

Abstract:
A semi-levered landing gear for an aircraft, comprising:a wheel truck including a longitudinally extending bogie beam and at least one forward wheel and at least one aft wheel rotatably supported by the bogie beam at forward and aft portions thereof, respectively;a main strut having an upper portion and a lower portion telescopingly connected to each other such that the main strut is extendable and compressible, the lower portion having a lower end pivotally connected to the bogie beam at a main pivot located between the forward and aft wheels, the upper portion of the main strut being adapted to be connected to the aircraft;an auxiliary strut having an upper end pivotally connected to the upper portion of the main strut and a lower end pivotally connected to the bogie beam at an auxiliary pivot longitudinally spaced from the main pivot, the auxiliary strut comprising a cylinder barrel having a closed end and an open end, a piston assembly slidably received through the open end of the cylinder barrel, and a lock-up device operable to permit extension of the piston assembly during a portion of a stroke thereof until the auxiliary strut reaches a predetermined lock-up length between a maximum length and a minimum length thereof, the lock-up device substantially preventing further extension of the piston assembly once the auxiliary strut reaches said predetermined lock-up length;the main strut and auxiliary strut being constructed and arranged relative to each other and the bogie beam such that, during a takeoff roll as the main strut extends, the auxiliary strut locks at said predetermined lock-up length before the main strut fully extends such that further extension of the main strut causes the bogie beam to pivot about the auxiliary pivot so as to tilt the bogie beam, whereby the landing gear is effectively lengthened.