GB479532A - Improved joint for a folding strut, arm or the like - Google Patents

Abstract

479,532. Retractable undercarriages for aircraft. THORNHILL, P. W., and ONIONS, J. H. Aug. 21, 1936, No. 23010. [Class 4] A retractable undercarriage comprises a wheel-carrying strut pivotally mounted about two axes, both of which are inclined to the planes containing respectively the longitudinal and normal axes and the lateral and normal axes of the aircraft and one of which is also inclined to the plane containing the longitudinal and lateral axes in order that the wheel carrying strut may have a minimum lateral movement in retraction. A wheel 11, Figs. 1 and 4, is carried by a shock-absorber strut 10 connected by the joint shown in Fig. 3, to a bracket projecting forwardly from spar 16. Strut 10 is braced by a lateral strut 12 and a folding strut 13 both pivoted to a rotatable sleeve 25, Strut 13 is pivotally connected to rear spar 34 and is folded and extended by a jack 14 acting on a sleeve 36 slidable over the intermediate hinge of the strut to serve as a locking member. The upper part of strut 13 may be braced as shown. The strut mounting comprises a block 17, Fig. 3, pivoted to forks 20, 21 respectively. Fork 20 is mounted on the spar bracket in such manner that its base is substantially parallel to a plane containing the longitudinal axis and disposed at an angle of 45‹ to the plane containing the longitudinal and normal axes. The axis of the pivot connecting block 17 to fork 20 is parallel to the base of the fork but is inclined at an angle of 45‹ to the plane containing the lateral and normal axes. The axis of the pivot connecting block 17 to fork 21 on strut 10 intersects the axis of the other pivot at right-angles and is normal to the axis of the strut. Figs. 5, 7, 8 and 9 in which 54 represents the wheel axle show in side elevation the action of the joint during retraction.