GB943854A - Telescopic strut - Google Patents

Abstract

943,854. Shock-absorbers. MESSERSCHMITT A.G. Aug. 1, 1961 [Aug. 1, 1960], No. 27833/61. Heading F2S. In a telescopic piston and cylinder shock absorber strut, particularly for aircraft landing gear, a differential piston rod has top and bottom portions 1, 2 which pass through associaated bearings at the respective ends of the cylinder, the bottom portion 2 is hollow and is provided with a separating piston 3 loaded on its lower side e.g. by compressed air or a spring, the space R above a main piston in the cylinder being connected to the space above the separating piston 3 by radial ducts 6 the passage of fluid through which is controlled by a non-return ring 7 mounted within a groove the main cylinder at the level of the ducts 6. During a retraction stroke the ring 7 bears against an upper collar 9 so that fluid flow from the space above the piston 3 is solely through throttle bores 8 in the collar 9. During compression the ring 7 is urged against a lower collar 10 so that fluid flowing in the reverse direction has an extra parallel path between the ring 7 and the upper collar 9, fluid flowing from the upper cylinder space R to the lower space R1 through bores 11 in the lower collar 10. The ring can be shaped to obturate some of the bores 8 in order to increase the damping during retraction. In a modification, Figs. 4, 5, not shown, the upper piston rod portion 1 is hollow and accommodates a separating piston in a supplementary compensating chamber.