GB704163A - Improvements relating to force transmitting devices - Google Patents

Abstract

704,163. Electric indicating systems. ROE & CO., Ltd., A. V. Feb. 13, 1952 [Feb. 26, 1951], No. 4589/51. Class 40 (1). Two co-axial members are connected by a diaphragm for transmitting load axially, the deflection of the diaphragm moving an armature differentially relative to two coils each forming part of a potential divider circuit, associated with an instrument for indicating the load and responsive to unbalance of the two circuits. As shown, a spring steel diaphragm 3 is secured at its periphery to a casing 1, and at its centre to an inner member 2 an extension of which carries a soft iron armature 6 located in the airgap between iron cored coils 5 secured to the casing 1. The coils are adjustably mounted by means of sleeves 7 to permit of balancing electro-magnetically at no load. The case 1 has a standard socket at one end for connection to a connecting rod and its other end is closed by a nut 12 which abuts against collars 13, 14 on the inner part 2 to limit displacement should the diaphragm fail. The member 2 ends in a ball bearing 15 between which and the connecting rod, tensile or compression forces may be applied and measured by the degree of electrical unbalance produced thereby. The coils 5 may be connected in an A.C. fed bridge circuit, Fig. 3, which is balanced at no-load by the potentiometer 18, the force transmitted axially being thus indicated by the meter 19. A rectifier ring 21 is provided so that a D.C. meter may be used. In another circuit arrangement, Fig. 4, the coils 5 are series connected via rectifiers with individual coils of the meter and fed with A.C. as shown, the meter coils normally carrying equal and opposing currents.