Patent ID: 6279854
Filing Date: 2001-08-28
Classification: B64C,F15B,F16F

Abstract:
A combined hydraulic damper and truck positioner mechanism for a landing gear of an airplane, the landing gear being swingingly attached to the airplane for reciprocating movement of the landing gear between an extended position and a retracted position, the landing gear including an elongate main strut having one end swingingly attached to the airplane and a longitudinally spaced second end, the landing gear further including a truck beam assembly pivotably attached to the strut second end, the truck beam assembly having at least two wheels journaled thereto, the combined hydraulic damper and truck positioner mechanism comprising:(a) a housing having one end adapted to be fastened to the strut and a second end, the housing having an interior bore with a predetermined cross-sectional area;(b) at least a first piston having a first piston head end and a longitudinally spaced second end adapted to be fastened to the truck beam assembly, the piston head being slidably received within the bore to form first and second chambers within the housing and for sliding movement of the piston in response to pivoting movement of the truck beam assembly when the piston second end is attached to the truck beam assembly;(c) a damping assembly in fluid communication with the housing, the damping assembly maintaining a substantially constant fluid pressure within the housing to maintain high stiffness and to dampen loads associated with the sliding movement of the piston when the landing gear is in the extended position; and(d) a preload assembly in fluid communication with the housing, the preload assembly preloading the first and second chambers to a predetermined fluid pressure.