Patent ID: 7426983
Filing Date: 2008-09-23
Classification: B64C

Abstract:
1. A damper ( 10 ) for an airplane landing gear leg, the damper comprising a main strut ( 11 ) and a rod-piston ( 13 ) having one end mounted to slide in said main strut along the axis (X) thereof, said rod-piston ( 13 ) co-operating with the main strut ( 11 ) to define a main hydraulic fluid chamber ( 15 ) and an annular hydraulic fluid chamber ( 16 ) communicating with said main chamber via an associated diaphragm ( 18 ), and said rod-piston ( 13 ) presenting internally two adjacent chambers ( 19 , 20 ) isolated from each other by a separator piston ( 21 ), one of the adjacent chambers ( 19 ) being a hydraulic fluid chamber which communicates with the main chamber ( 15 ) via an associated diaphragm ( 17 ), and the other of the adjacent chambers ( 20 ) being a pressurized gas chamber, the damper further comprising a first secondary strut ( 26 ) having one end mounted to slide telescopically on the other end of the above-mentioned rod-piston ( 13 ), co-operating with an end wall ( 25 ) of said rod-piston to define a first secondary hydraulic fluid chamber ( 30 ) which is closed by an associated hydraulic locking member ( 36 ), and a first annular secondary hydraulic fluid chamber ( 31 ) which is connected to an associated control circuit ( 34 , 35 ) thus enabling the total length of the damper ( 10 ) to be shortened in order to allow the landing gear leg to contract, and a second secondary strut ( 37 ) mounted to slide telescopically on the other end of the first secondary strut ( 26 ), co-operating with an end wall ( 28 ) of said first secondary strut to define a second secondary hydraulic fluid chamber ( 39 ) which is closed by an associated hydraulic locking member ( 46 ), and a second annular secondary hydraulic fluid chamber ( 40 ) which is connected to an associated control circuit ( 44 , 45 ), thus enabling the total length of the damper ( 10 ) to be lengthened in order to extend the landing gear leg.