GB467415A - Improvements relating to undercarriages for aircraft - Google Patents

Abstract

467,415. Shock-absorbers. DOWTY, G. H. Dec. 12, 1935, Nos. 34513 /35 and 17906 /36. [Class 108 (iii)] In an aircraft undercarriage of the kind in which alignment of a landing-wheel or equivalent in its appropriate track is maintainec by the torsional stiffness of a tele scopic, shock-absorbing leg carry ing the wheel &c., the leg consists of two telescopic structures, the landing-wheel &c. being carriec by one of the telescoping, tubular parts 7, 9 of one of the structures the other part 7 of which is secured to the aircraft, while the telescoping parts 14, 15 of the other structure are offset from those of the main structure anc act as a guide therefor. As showr the tubes 7, 9 are separatec by a spring 11 which absorbs the landing-shock and the parts 14, 15 comprise tubes rigidly secured to the tubes 7, 9 respec tively, at least at two points, by members 12, 13. The structure 14, 15 incorporates a hydraulic or pneumatic dashpot consisting of a rod 16 which passes through a plug 17 closing the upper end of the tube 15, and carries a piston 18 of smaller diameter than the internal diameter of the tube 15, relative longitudinal movement of the tubes 14, 15 being resisted by flow of fluid through the restricted annular passage around the piston 18. Either structure may act as a shock-absorber and/or as a fluid or friction damper. In a modification, the guide structure comprises a rod pivoted at its lower end to the tube 9 and slidable in a sleeve pivoted to the tube 7. In another construction, the guide structure, comprising telescoping tubes incorporating dampers and shock-absorbing means, is mounted inside the main structure. The guide may consist of a rod fixed to one part of the leg and having a cross-head engaging a slot in a plate fixed to the other part. When arranged outside the main structure, the guide may be hidden by a fairing. To afford increasing resistance to torsion proportionally with compression of the leg, the two structures may be arranged so as not to be parallel with one another.