GB708354A - Improvements relating to aircraft retractable landing gear - Google Patents

Abstract

708,354. Aircraft alighting gear. DOWTY EQUIPMENT, Ltd. Nov. 25, 1952 [Sept. 17, 1951], No. 21811/51. Class 4 Aircraft retractable landing gear of the kind comprising a telescopic shock absorbing leg having a torque linkage to prevent relative rotation of the telescopic parts comprises leg contracting mechanism having a member mounted on a pivot fixed to the aircraft at a point offset from the axis of retraction of the leg, which member is adapted to collapse the torque linkage during retraction and so shorten the leg, the landing gear including valve means arranged to release fluid from the shock absorber during retraction. In the embodiment of Fig. 1, the cylinder 21 is mounted telescopically within cylinder 19, and the torque linkage 24 and 25 is joined between the cylinders. An arm 48 is pivoted to link 24 and to a collar 46 on cylinder 19, which collar bears a ring 45 connected to pivot 43 fixed on the aircraft, by extensible rod 51, 52. Retraction of jack 15 breaks the strut 7, 9, and piston rod 17 of jack 15 fastened to pivot 18 pulls up the leg. Rod 51, 52 extends to a point determined by bush 50 within cylinder 51, and then pulls collar 46 along cylinder 19, collapsing the torque linkage, valves 39 and 41 are operated simultaneously with jack 15 to allow fluid to flow in or out of the shock absorber. The lost motion of rods 51, 52 allows collar 46 to move under shock absorption when the landing gear is in use, and ring 45 on collar 46 allows castoring of the leg. In the embodiment of Fig. 3, link 60 is provided with an extension 63 which is rotated about pivot 61 by contact with the fork 67 on the resiliently mounted member 65. In operation, the arm 63 is first displaced, collapsing the linkage, and then arm 65 is carried past the dead centre of the resilient device 71. The leg must be centred before retraction.