GB582005A - Improvements in engine mountings - Google Patents

Abstract

582,005. Determining dimensions of materials. DE HAVILLAND AIRCRAFT CO., Ltd., and BUCHER, J. B. Feb. 7, 1944, No. 2226. [Class 37] [Also in Groups XIX and XXXIII] A mounting for an engine driving counterrotating airscrews comprises resiliently-yielding means between at least one engine foot and its bearer, in combination with means consisting of rigid non-yielding members for restricting the range of the yielding movement to a small amount beyond which range the loads are transmitted without further yielding, and means for measuring the movement of the engine foot relative to the bearer, or a quantity which is a function of the movement, to measure the residual or differential torque transmitted to the engine bearers. In the form illustrated, Belleville washers 26 are provided between the engine foot 16 and bearer 20, the extent of movement of the washers being limited by the engagement with the bearer of rigid members 28 mounted on the foot. For the purpose of measuring the load on the bearer, and thus the residual torque, the members 28 support the edges of an electric strain gauge 36 of the type described, for example, in Specification 549,140, the lower surface of the diaphragm being engaged midway between the supports by a projection 38 carried by the bearer 20. According to a modification, Fig. 4 (not shown), two engine feet, one on either side of the engine, are each provided with two gauges, one of which is strained by downward movement of the foot and the other by upward movement thereof, the gauges being arranged in pairs as opposite arms of a Wheatstone bridge such that vertical movements of the engine do not affect the balance of the bridge, thereby eliminating the effect of engine oscillations in the vertical plane. According to the Provisional Specification the yielding movement of the engine foot may vary the width of an air gap in a variablereluctance magnetic circuit. Further, in the case of an engine with four feet, each one may be associated with an electric strain gauge, those on each side of the engine being connected in series to form an arm of a Wheatstone bridge, to eliminate the effect of vertical and pitching oscillations.