Patent Number: 6,168,142

Title: Hydraulic damper with elastomeric spring assembly

Abstract: A hydraulic damper assembly has a barrel-piston assembly and a spring assembly. The barrel-piston assembly has a barrel with a top portion having an open end, and a piston extending through the open end. The piston has a bottom portion that is located inside the barrel. The piston and the barrel also define an annular space in which is a barrel shoulder and a piston shoulder. The barrel shoulder radially extends into the annular space from the barrel top portion. The piston shoulder radially extends into the annular space from the piston bottom portion. The spring assembly is disposed in the annular space between the barrel shoulder and the piston shoulder. When the piston is extended from the barrel, the shoulders compress the spring assembly and, thereby, reduce the amount of force required to compress the piston which enables the damper to be charged to a higher nitrogen pressure. An object of the invention is to provide a damper assembly for aircraft landing gears that permit high nitrogen pressures to increase ground resonance clearance at high aircraft gross weight and not be fully extended at low aircraft gross weights to avoid ground resonance problems. Another object of the invention is to provide a cost effective damper assembly that is easily retrofitted into current designs of helicopter landing gears.

Inventors: Bolukbasi; Akif O. (Phoenix, AZ), Saliba; Paul (Mesa, AZ), Pester; Lowell (Mesa, AZ)

Assignee: McDonnell Douglas Helicopter Company

International Classification: F16F 9/02 (20060101); F16F 9/58 (20060101); F16F 005/00 ()

Expiration Date: 01/02/2018