GB259673A - Improvements in and relating to electric inductance coils - Google Patents

Abstract

259,673. Halsall, C. F. July 15, 1925. Inductances.-Air-spaced coils wound on skeleton supports have their turns supported by, wound around, and embedding into soft rubber spacing-members. The former may comprise a cardboard, ebonite or other cylinder a, Fig. 2, with longitudinal ribs a<1> faced with rubber a<2> over which a layer of wire b is wound, subsequent layers b<1> being separated by ebonite or like strips c faced with rubber c<1>. The rubber facings may be applied in a plastic condition to the strips c. In a modification, the ribs a<1> and strips c are replaced by rubber strips. In a further modification, superposed layers of winding are separated by rubber or rubber-covered elongated rings. In a further modification, Fig. 6, superposed layers of spaced or adjacent turns are separated by a zig-zag winding of rubber cord h wound about two series of pins in forming the coil. The cord h may be replaced by rubber-enclosed string or by rubber-covered flex which may constitute a separate winding coupled to the main winding and brought out to separate terminals to form, for example, an aperiodic coupled aerial coil. In other modifications, rubber cord is bent backwards and forwards over successive layers, or corrugated rubber separators are used. The coils may be tapped, or used in variometers or varioccuplers, or secured to a plug-in block by an insulating strip.