GB606163A - Improvements in or relating to landing gear for aircraft - Google Patents

Abstract

606,163. Aircraft landing gear. BENDIX AVIATION CORPORATION. Feb. 21, 1946, No. 5416. Convention date, June 25, 1945. [Class 4] [Also in Group XXXII] In aircraft landing gear having a shock strut comprising two telescoping members, one 14 connected to the aircraft and having a bearing 50 at its lower end, the other 12 carrying a ground contacting element (not shown) and supporting a bearing 48 at its upper end, an annular chamber 66 being formed between the bearings 48, 50, into which fluid is forced to shorten the strut prior to retraction, an annular floating piston 52 is located in the annular chamber to act as a spacer for holding the bearings 48, 50 a predetermined distance apart in the fully-extended position of the strut and to act as a piston under the action of the pressure fluid to shorten the strut. The floating piston 52, Fig. 3, has inner and outer packing rings 74, 76. An inlet 80 to the lower part 67 of the space 66 below the piston 52 provides a connection with an hydraulic pressure system on the aircraft so that according to the setting of suitable control means (not shown) the space 67 may be either subjected to hydraulic pressure or connected to a reservoir of the system. The upper tubular member 14 carries a concentric hollow piston rod 28 the piston 30 of which has an orifice 32 which co-operates with a metering rod 18 carried by the member 12. An annular member 64 in the upper part of the space 66 allows relatively free flow into the space 66 but is pressed against the bearing-spacer member 48 by outward flow which has to pass through orifices 72 in the member 64. Oil and air are charged into the leg at 22. Holes 38, 40, 42, 44, 46 permit free communication between the interior and exterior of the pistonrod 28. In operation, on take off, the leg extends under gravity and air pressure in the space above the piston 30, to the position shown, the piston 52 and member 64 acting as combined spacing member between the bearing members 48, 50. Hydraulic pressure is then applied to the connection 80 and acts on the piston 52 to retract the lower tubular member 12 into the member 14 and during this operation air may be released to a suitable reservoir (not shown). The shock absorber is then sufficiently shortened to allow the landing gear to be retracted. After subsequent extension of the landing gear prior to landing the pressure is released from the inlet 80 and the leg extends once more to be ready to withstand the landing shock.