GB648931A - Improvements in or relating to aircraft and like shock absorbers - Google Patents

Abstract

648,931. Oleo pneumatic shock absorbers. BRITISH MESSIER Ltd. April 13, 1948, No. 10237. [Class 108(iii)] In a shock absorber comprising a piston- and-cylinder device for compressing liquid through a restricted passage or passages out of the cylinder against gaseous pressure when the shock absorber is loaded and a gaseous pressure vessel to receive the liquid divided into two chambers, one in communication with the cylinder and of high compression ratio and low initial gas pressure and the other of lower compression ratio and higher initial gas pressure, the two chambers are arranged in the same casing and are separated from one another by a separator piston therein which is urged by the pressure in the chamber of higher initial pressure towards a stop and a reducing valve is provided which connects the two chambers together. In the arrangement shown, provided which connects the two chambers together. In the arrangement shown, low and high pressure air chambers 18 and 19 respectively in the upper end of a hollow piston rod 13 are separated by a freely slidable separator piston 14, which is urged by air pressure in the chamber 18 towards a stop 15. Liquid in the lower end of the hollow piston rod communicates through restricted passages 20 in a piston 12, with liquid in a main cylinder 11. A reducing valve 17 within the piston 14 enables both chambers to be charged with air through a single valve 16. When during compression of the shock absorber the pressure of the air in chamber 19 is raised to that of the air in the chamber 18, the separator piston moves away from the stop 15 and the air in both chambers is compressed together. Specification 629,970 is referred to.