GB461144A - Improvements in resilient struts for use more especially in connection with the landing wheels of aeroplanes - Google Patents

Abstract

461,144. Shock-absorbers. RIBBESFORD CO., Ltd., and ONIONS, J. H. Aug. 15, 1935, No. 22936. [Class 108 (iii)] In a resilient strut particularly for aircraft comprising telescopic, tubular, plunger-andcylinder members 14, 10, relative movement of which is resisted by flow of liquid through one or more restricted passages, a floating piston 38 separates the liquid from compressed gas or air which supports the normal axial load. As shown in Fig. 1, the plunger-head 15 contains a series of large apertures 19 and a small central opening 20, flow of liquid through which is regulated by a centrally-apertured flutter-valve 17 such that, on compression of the strut, liquid flows relatively freely through the apertures 19 and valve-aperture 21 while on extension the valve 17 is pressed downwardly, the flow of liquid being restricted by the opening 20, the apertures 19 being closed by the valve. The lower end of the cylinder 10 is closed by a plug 22 secured by three diametral pins &c. 23 and provided with an oil-filling passage 25. Compression of the strut is arrested by an annular buffer 27 resting on the plug 22 and extension by a resilient ring 28 surrounding the plunger 14 and resting on a spacing tube 30. A preferably resilient sleeve 43 acts as a stop for the floating piston 38, the sleeve bearing against another plug 32 which closes the outer end of the plunger 14, and is fitted with an air or gas inlet valve 37. The relative disposition of the parts may be reversed as in the construction shown in Fig. 2. In this case the upper plug 45 supports a central rod or tube 46 carrying at its lower end a piston 47 having small apertures 48, the piston and tube working with clearance in the body and head respectively of the plunger tube 14. The valve 17 is normally spring-pressed to close the apertures 19 in the plunger-head 15. The floating-piston 38 may have an axial guidestem 53 slidable in the tube 46. The plug 45 comprises portions having bevelled edges 54, 56 adapted to force outwardly into contact with the cylinder 10 a packing ring 58 when the two portions are clamped axially by a nut 57. A plug 59 closing the lower end of the plunger tube 14 is sealed by an L-section packing-ring 63 preferably of rubber.