GB1010087A - Retractable undercarriages for aircraft - Google Patents

Abstract

1,010,087. Aircraft undercarriages. ELECTRO-HYDRAULICS Ltd. May 26, 1964 [May 30, 1963], No. 21758/63. Heading B7G. A retractable undercarriage for aircraft comprises a beam, at least one pair of wheels consisting of an inboard and an outboard wheel, each wheel being mounted respectively on a mounting member for pivotal movement relative to the beam, which is hingedly connected to the aircraft about an axis parallel to the longitudinal axis of the aircraft, and means for retracting and lowering the undercarriage, the arrangement being such that, on retraction, the beam is pivoted from a substantially horizontal position to a substantially vertical position, thereby causing each inboard wheel to swing downwards and inwards into a substantially horizontal position and each outboard wheel to swing upwards and inwards into a substantially vertical position. In Fig. 1 the aircraft fuselage and the envelope into which the undercarriage is to be retracted is indicated by dotted lines. A beam 1 is mounted on the aircraft at 2 for pivotal movement under the control of an hydraulic jack 3 also mounted on the aircraft at 5. Bell-crank members 7 and 12 are pivotally mounted on the beam to support the axles of wheels 6 and 10 respectively, arms 15 and 18 of the bell-cranks being connected by links 14, 16 to fixed points 5, 17 on the air frame. In the extended position shown in Fig. 1 locks in the jack 3, or elsewhere, hold the beam 1 down and movement of the wheels is resisted by tension in link 14 and compression in link 16. Extension of jack 3 rotates beam 1 to the position of Fig. 2, the links 14 and 16 constraining the wheels 6 and 10. to rotate to the substantially horizontal and vertical positions shown. Other linkwork arrangements are described together with a preferred constructional embodiment for a four-wheel bogie undercarriage. Specification 956,042 is referred to.