GB672541A - Improvements in electric cables suitable for use for currents at high frequencies - Google Patents

Abstract

672,541. High-frequency cables. BRITISH INSULATED CALLENDER'S CABLES, Ltd. Feb. 7, 1951 [Feb. 8, 1950; March 20, 1950], Nos. 3284/50 and 6894/50. Class 36. A tubular conductor 2 comprises two coaxial layers 3, 4, each comprising a metal strip bent to form an approximately complete cylinder, the inner layer having outwardly projecting transverse ribs 10 and the outer layer having inwardly projecting transverse ribs 11, the two sets of ribs being approximately equal in depth and fitting between each other so that the layers are spaced apart by the depth of the ribs. The spacing between the ribs is approximately the same for both layers and may be between once or twice the mean diameter of the conductor. The longitudinal edges 5, 6 and 7, 8 of the strips may lie parallel with the axis of the tube, or rim in a helix of long pitch. The ribs may be arranged so that the two ends of each rib meet (Fig. 1), or they may be skewed (Fig. 5). In the latter case the ribs 10 may be positioned with respect to the ribs 11 so that the layers are locked longitudinally. The layers may also be held in position by soldering or cementing along the ridges of one or both layers. To maintain accurately the inner diameter of the conductor the edges 5, 6 of the inner layer are caused to contact and are held in position by a binder 12 applied about the outer layer. The binder may be of fabric, plastic, copper or of steel if electro-magnetic screening is required. The conductor thus formed may be used as the outer conductor of a coaxial pair, separated by discs 9 from the inner conductor 1.