GB206899A - Improvements in or relating to coil holders for wireless signalling systems - Google Patents

Abstract

206,899. Igranic Electric Co., Ltd., Curtis, A. H., Wright, S. R., and Mackley, A. H. Aug. 8, 1922. Inductances. - In a multiple-coil variable inductance for wireless signalling having independently supported angularly adjustable single coils, the coils are angularly adjustable about a diametral axis parallel to the axis or axes of the primary angular adjustment of the coil supports relatively to each other, the relative position of the coil supports and the angular position of the coils in the supports being adjusted separately or simultaneously for coarse and fine tuning. The electric connections for each coil may pass through the diametrically opposite pivots to diminish leakage. In one form with three coils 25, Fig. 1, the ends of the coils are connected to pivots 24 detachably engaging holes or recesses in resilient horizontal arms 20, 21. The coils are angularly adjusted about the pivots 24 by means of an operating rod which is forked at one end to engage the square insulating spindle 68, or which is rotatably mounted in one of the arms 20, 21 and connected to the spindle 68 by worm and wheel gearing, by a flexible drive in the form of a spiral spring connecting the end of the rod to an end of the spindle, or by a friction drive comprising a pulley 72, Fig. 6, on the operating rod 46 engaging a friction disc 74 on the coil. 'Each coil may be mounted on its pivots by means of plates 64, Fig. 1, on the coil engaged by bent-over strips 65 and provided with sockets to engage the spindle 68, or flat coils may be fixed in recesses in a tubular spindle into the ends of which the pivots 24 are screwed. The arms 20, 21 have bent ends 30 engaging grooves 29 in insulating carrier rods 26, the arms being adjustably locked in the grooves by screws 31, 36 engaging distance pieces 32. Different diameters of coils may thus be received between the arms 20, 21, and the positions of the coils may be adjusted along the rods 26. The centre rod 26 may be fixed and the outer rods rotatably mounted and operated by means of levers 40 clamped to the rods 26 or to the arms 20, 21 or by means of the rods provided for rotating the coils about the pivots 24. The electric connections for each coil engage holes 39 in the pieces 32 or are clamped in holes 37 in the screws 36 by spring plates 38, the current passing through the arms 20, 21 and pivots 24. Coils of different diameters may be used together to provide variometer adjustment of one coil within a larger annular coil. In a modification, Fig. 2, the arms 20, 21 are adjustably locked on guides 50, 51 secured at opposite sides of an insulating block 54 carrying plug-andsocket couplings to engage corresponding couplings on standard coil holders having angularly adjustable coil supports. The Provisional Specification describes pivotal supports for a coil in the form of inner and outer tubes in frictional engagement, the inner tube being rotated for fine adjustment of the coil by means such as worm and wheel gearing.