GB458005A - Improvements in and relating to adjustable struts for air-craft - Google Patents

Abstract

458,005. Aircraft alighting - gear. ELEKTRONMETALL GES., 26, Pragstrasse, Bad Cannstatt, Stuttgart, Germany. March 30, 1936, Nos. 9451 and 9452. Convention dates, March 28, 1935 and March 27, 1936. [Class 4] [See also Group XXX] In a strut of variable length for the undercarriages of aircraft comprising a piston moved in a cylinder under the influence of a pressure medium and having balls for effecting the locking of the strut in different positions, the balls lie in recesses in such a manner that in the locking positions tensile and compressive forces are taken up and transmitted in both directions. The main piston 2 is formed with recesses in which are located balls 8, 9 which in the retracted and extended positions of the strut are engaged with recesses in the main cylinder 1 by sleeves formed on looking pistons 4, 5. To extend the strut pressure built up by fluid admitted through a pipe 12, moves the piston 4 against its spring 6 and then operates on the piston 2 which together with the rod 3 is moved downwardly. Towards the end of the extension stroke the balls 9 engage the tapered end of the sleeve of the piston 5 which is pressed downwardly against a spring 7 until the balls engage in the recess 14 when the sleeve moves upwardly under the action of the spring 7. The strut is contracted in a similar manner by fluid admitted through the pipe 13. In an alternative arrangement, Fig. 3 (not shown), operating cables are attached to levers connected to the upper and lower locking pistons so that the unlocking operation may in each case be effected independently of the application of fluid pressure. In a further modification, Fig. 4 (not shown), the unlocking piston is connected to a lever operated by a piston moving in a cylinder fed from an auxiliary source of pressure.