Patent ID: 8763997

Claim:
A damper for a landing gear of a helicopter, comprising: a barrel having a bottom end, a top end, and a cavity; a piston having a shaft and a compression member connected to the shaft, the compression member and at least a portion of the shaft extending into at least a portion of the cavity of the barrel via the top end of the barrel such that the compression member and the barrel define a first hydraulic cavity between the compression member and the bottom end of the barrel and the compression member and the top end of the barrel define a second hydraulic cavity between the compression member and the top of the barrel, the piston linearly moveable between a retracted position and an extended position upon application of an axial force to at least one of the barrel and the piston; a stack of disc springs disposed within the first hydraulic cavity in a compressed state between the bottom end of the barrel and the compression member, each of the disc springs having a substantially concave side and an opposing substantially convex side, the disc springs stacked in an alternating pattern such that any two adjacent washers have their like sides positioned adjacent to each other; a spring disposed within the second hydraulic cavity such that the spring is compressed between the compression member and the top of the barrel when the piston is in the extended position thus regulating the upward linear movement of the piston relative to the top end of the barrel; a hydraulic fluid disposed inside at least a portion of the first hydraulic cavity and at least a portion of the second hydraulic cavity; at least one valve disposed in the compression member so as to establish bilateral fluid communication between the first hydraulic cavity and the second hydraulic cavity through the valve; and at least one pressure relief member having a normal mode of operation and a crash mode of operation such that in the normal mode of operation the pressure relief member precludes fluid flow through the pressure relief member, and in the crash mode of operation the pressure relief member establishes greater fluid flow from the first hydraulic cavity through the pressure relief member.