GB742309A - A retractable undercarriage for aircraft - Google Patents

Abstract

742,309. Aircraft undercarriages. ELECTRO-HYDRAULICS, Ltd. Oct. 23, 1953 [Aug. 29, 1952]. No. 21776/52. Class 4. A retractable aircraft undercarriage includes ground contacting elements comprising at least one wheel or set of wheels in tandem with another wheel or set of wheels, and also a member articulated to the undercarriage structure and carrying said wheel or wheels, and means carried by said elements which means on retraction, are adapted to co-operate with means on the aircraft or undercarriage to alter the articulated relation of the ground contacting elements to the undercarriage structure to facilitate storage of the undercarriage. In one embodiment (Fig. 1) the invention is applied to an undercarriage constructed as described in Figs. 4 and 5 of Specification 674,237, and provides rollers 61, 59 on the bogie 52 adapted to co-operate with cam surfaces 62, 63 on strut 4 to tilt bogie 52 to lie parallel with the leg 2 when retracted. In the embodiment of Figs. 6 and 9, the main undercarriage leg 1 is supported by a rigid strut 4 pivoted to the aircraft at 6 and to the leg at 5, and by a bearing 22 abutting stops on the aircraft (not shown) and locked by levers 41 spring-biased by spring-box 70 to engage studs 42 on the aircraft. On retraction, a jack 66 extending between the strut 4 and lug 67 contracts, and an auxiliary jack (not shown) removes lever 41 from studs 42, and as the main jack contracts, bearing 22 pivots on bars 39 about pivot 40, so that bars 39 and leg 1 jackknife to the retracted position. As shown in Fig. 9, rollers 61 on the bogie 52 contact a recess 76 in a resiliently mounted hook 75.so that as leg 1 and strut 4 become parallel, the bogie 52 is constrained to tilt parallel to leg 1. Brake torque reaction devices 73 are provided as described in Specification 635,842. An auxiliary shock-absorber 56, 57 is pivoted to a lug 50 on the leg and slides in a sleeve (not shown) pivoted at 71 to the bogie so as to bias the rear wheel to touch down first, and allow the bogie to tilt relatively to the leg. Specification 635,885 also is referred to.