GB208809A - Improvements in or relating to inductance coils used in connection with wireless receiving apparatus - Google Patents

Abstract

208,809. Igranic Electric Co., Ltd., Curtis, A. H., and Wright, S. R. Sept. 30, 1922. Inductances.-In variable inductance coils for wireless receiving apparatus of the kind comprising two concentric coils wound to form the middle zones of hollow spheres and relatively adjustable about a common diametral axis as a variometer or as a vario-coupler, each coil is wound diagonally in opposite directions to form an openwork self-supporting structure. Each half of each coil may be wound separately, the turns of wire 30, Fig. 4, being in the form of circular arcs spaced apart and each turn locking the preceding turn in position. The two halves 10, 11, Fig. 1, of each coil are connected by an inner or outer central ring 12 of insulating material. The inner coil may be mounted on a tube 16 fixed to a base 17, the leads from the coil passing through the tube 16 to terminals 22, 23 on the base 17. The outer coil may be mounted by a supporting band and screws 20 on a sleeve 18 rotatably arranged on the tube 16 and resting on the base 17, the leads from the outer coil being connected to separate terminals 24, 25. A handle 21 on the sleeve 18 facilitates adjustment of the outer coil without approach of the operator's hand to the coils. The outer coil may be fixed and the inner coil adjustable.