GB237672A - Improvements in inductance coils for use in wireless telegraphy and telephony - Google Patents

Abstract

237,672. Shephard, W.S. May 16, 1924. Inductances. - Inductances or tuning coils for use in wireless telephonic receiving apparatus are provided with a form of winding enabling a coil of very low self capacity to be produced. The coil comprises a short cylindrical former a, Fig. 1, of insulating material with a series of opposite slots at each numbered 0-59. Covered wire is passed from within the former a out through the slots 59/0 in one end of the ring across the outside and in through a slot 1 in its opposite end, then chord like across the ring and out through a slot in the same end, across the outside of the ring and in through the slot 16 in its opposite end and so on producing a coil of U-shaped cross-section the winding outside the ring forming the bottom of the U. The wire at no point passes in any way interiorly from end to end of the ring. Fig. 2 shows the development of the first three turns of the winding. The ring should be as thin as possible and perforated. The ring shown is of substantial thickness only for the sake of clearness. Where there is more than one layer, successive layers may be separated by an insulating strip. The lengths of wire outside the former are preferably less but may be more than the chord like parts inside the former. The distances traversed bv the wire chord-like across the former and/or around for a part turn or straight across outside of the former may vary in the same or differing layers.