GB650547A - Retractable landing gear for aircraft - Google Patents

Abstract

650,547. Aircraft landing-gear. ELECTROHYDRAULICS, Ltd., and PERDUE, J. Dec. 15, 1947, No. 33070. [Class 4] In a retractable landing-gear for aircraft of the kind in which the landing wheels are mounted in a frame in tandem or in a bogie frame pivoted on a resilient telescopic unit and in which a mechanical linkage is provided for automatically altering the angular relationship between the frame and the resilient telescopic unit as the undercarriage is raised or lowered, the means provided for altering the angular relationship about an athwartships axis comprises a mechanical linkage between a pivot point on the aircraft and a pivot point on a frame in front of or behind said axis, said linkage being so arranged that as the angular relationship is altered no axial movement in or of the resilient telescopic unit occurs. Two pairs of wheels 2, 3 are carried by a bogie 1 which is pivotally mounted at 4 from the lower end of a resilient telescopic leg 5 pivotally connected at 6 to the aircraft structure and retracted by a jack 21 and held in the down position by break joint back stays 7, 8. The lower stay 7 is pivotally connected to the undercarriage leg at 10 and is extended forwardly by a link 13, pivotally connected at its lower end to the bogie 1 by a resilient link 18. When the jack 21 is actuated to retract the undercarriage the stays 7, 8 break upwardly and, by means of the linkage 13, 18, cause the wheels and the bogie to lie substantially parallel to the leg 5 as shown by chain-dotted lines. The link 18 comprises a piston and cylinder arrangement having a spring interposed between the underside of the piston and the lower end of the cylinder such that the spring must be compressed before the angular relationship between the bogie and the leg can be altered.