GB538298A - Improvements in or relating to retractable undercarriages for aircraft - Google Patents

Abstract

538,298. Aircraft undercarriages. FAIREY AVIATION CO., Ltd., and COSTIGAN, F. J. April 30, 1940, No. 7777. [Class 4] A retractable undercarriage in which a wheel is adapted to be swung laterally upwards and slightly rearwardly to a position between the spars of an aircraft wing, comprises two jointed struts, pivoted to the oleo-leg and to the aircraft, which lie respectively in a transverse and a fore-and-aft plane when the wheel is lowered, the first mentioned strut being connected with a hydraulic jack whilst the joint of the second mentioned strut is connected by a link to a point on the aircraft offset from said fore- and-aft plane towards the same side as the other jointed strut. An oleo-leg b is pivoted about a transverse pivot upon a tubular member e mounted in bearings so as to be rotatable about a fore-and-aft axis on the aircraft. The leg b is connected by a universal joint g to the lower member h of a jointed strut h, j pivoted about a fore-and-aft axis k. An extension q is separately pivoted about the same axis k with lost motion provided by abutments r, s respectively on the extension q and the upper part j of the strut. A hydraulic jack u is connected between the extension q and a bracket x on the tube e for breaking the strut and raising the leg, the lost motion of the extension q being utilized for withdrawing a locking bolt co-operating with a quadrant n on the part h of the strut. The oleo-leg b is also connected to a bracket on the tubular member e by a jointed strut 13, 14, the cental pivot 17 of the strut being connected by a link 18 and a universal joint 19 to a fixed point on the aircraft wing, offset as shown from the fore-and-aft .member e, so that the leg b is moved rearwardly as it is raised. The extension q is fast upon a short fore-and-aft shaft carrying a spring-urged arm 21 co-operating with a hook 23 on the leg b to secure the leg in its raised position. initial movement of the jack u disengaging the arm from the hook before lowering the leg. A bracket 25 on the locking bolt of the strut h, j actuates a switch 26, when the bolt shoots home, to actuate an indicator showing that the undercarriage is down.