GB355348A - Improvements in undercarriages for aeroplanes - Google Patents

Abstract

355,348. Aeroplane undercarriages. GRAY, W. E., 8A, Bank Parade, Edgware, Middlesex. May 23, 1930, No. 15975. [Class 4.] In an aircraft undercarriage of the type wherein two sets of wheels are provided one set in front of, and one under or slightly in rear of, the centre of gravity of the aircraft, the front set of wheels is arranged to have a considerably greater travel of springing than the rear set. A spring arrangement is used for the front wheels having a load-deflection curve of the type shown in Fig. 1, wherein AB represents deflection, BC load, and CD rebound deflection. In one such arrangement, Fig. 2, a long coiled spring K is so arranged as to be initially compressed by a shorter rebound spring J placed below the moving element H fixed to the weight carrying member which spring acts on the spring K over the first part of the travel corresponding to the initial steep part of the curve shown. After further travel a short coiled spring L is arranged to come into action causing the second steep slope of the curve. All three springs are approximately of the same strength. When the aircraft is at rest on the ground the front wheel deflection corresponds to the earlier part of the flatter portion of the curve. According to modifications a single spring may be used having a portion of lesser diameter or of larger gauge material or of both. When tyres of very large diameter are employed the springing to give large travel has a load-deflection curve similar to the centre portion only of the curve in Fig. 1. Specifications 274,167, 289,109, 338,514, and 338,515, [all in Class 4, Aeronautics], are referred to.