GB242010A - Improvements in variable electric condensers - Google Patents

Abstract

242,010. Dunn, W. F., and Tansley, E. A. Aug. 12, 1924. No Patent granted (Sealing fee not paid). Condensers of the kind comprising diametrically opposed plates mounted on a centrallydisposed revoluble spindle coacting with two sets of similar fixed plates, each set of movable plates being electrically connected to a set of fixed plates, have the rotatable element in the form of a pair or pairs of dielectric discs mounted on a spindle, and between the discs a pair or pairs of substantially semi-circular conducting plates are inserted in diametrically opposite positions, the plates being spaced apart from each other and from the spindle and the pair or pairs of discs being secured together. The rotatable element comprises a pair of insulating discs a, a<1> between which are inserted in a pair of conducting plates b, b<1>, spaced apart from each other and from the spindle c, and provided with lugs d, d<1> for attachment of the leads e. The spindle c rotates in a bush c<1> secured to the base by means of a nut c<2> and locking ring c<3>, the discs a, a' being secured thereon by nuts c<4>. The discs engage pairs of stationary plates h, h<1> supported on pins i by means of distance pieces h<2>, nuts i<1> and sleeves i<2>, and preferably cut away at h<4>, h<5> to give a " square law " variation in capacity. For securing the leads e, a pair of insulating discs m, m<3> are clamped against one another with the leads between them, the leads being soldered to the pins i and threaded through holes m<1>, m<2> in the disc m<3>. The leads are helically coiled or otherwise maintained in tension, while two of the pins i may serve as stops i<7> to be engaged by an arm c<5> on the spindle to limit the rotation of the latter to a half-circle.