GB591252A - Expansible shorting piston for coaxial electric lines - Google Patents

Abstract

591,252. Electric resonators. STANDARD TELEPHONES & CABLES, Ltd. May 4, 1945, No. 11348. Convention date, June 26, 1944. [Class 40 (iii)] A coaxial resonator contains a short-circuiting annular piston with clearances between its edges and the inner and outer conductors, so that its position can be freely adjusted ; and resilient annuli which can be expanded so as to look the short-circuiting piston position, while ensuring conductive continuity. These latter may be solid resilient annuli, Figs. 1, 2 (not shown), which can be compressed axially by means of screw threads formed upon four longitudinal guide bars which are geared as to rotate together ; as a result of this compression, metallic strips or coatings are pressed against the conductors so as to ensure conductive continuity. Alternatively the resilient expansible annuli may comprise two rings, Figs. 3, 4, of arcuate segments 28, 29 which are composed of conductive material &c., and can be moved apart so as to grip against the outer and inner conductors respectively. Movement is effected by pumping air, oil, or some other fluid into a tubular resilient annulus 40 Fig. 4, and 41, Figs. 4, 3, through a bore formed in one 44, Fig. 3, of a set of guide rods 18, 44, by means of which the piston can be positioned. Pressure is applied by depressing a piston 49, which is then held down by a catch 53 engaging a collar 54. Electrical continuity is assured by radial bowed conductive strips 39. In a modification, Figs. 5, 6 (not shown), two coaxial annular fluid-pressure chambers are provided with conducting surfaces and, when pressure is applied, lock an annular piston in position, while ensuring a . conductive connection between it and the inner and outer conductors.