GB257713A - Improvements in or relating to rheostats for use in radio apparatus - Google Patents

Abstract

257,713. Igranic Electric Co., Ltd., Curtis, A. H., and Dandridge, G., F. July 27, 1925. Wire resistances, cored and mounted on curved surfaces; variable resistances-In a rheostat of the type in whch the resistance element is held between grooves in the edges of two discs mounted on a spindle, the discs are adjustable so as to take resistance elements of different widths. In the arrangement shown in Fig. 1, two resistance elements 2 are carried on the same spindle 4 by discs 1<a>, 1<b> furnished at their edges with projecting rims 8 recessed to form the grooves which hold the resistance elements. One of the pieces 1<b> is held against a shoulder on the spindle by a nut 18; a piece 1<a> and a second piece 1<b> are held against the first piece 1<b> by a second nut, and a second piece 1<a> by a nut 20. In the arrangement shown in Fig. 4, the pieces 1<a>, 1<b> are spaced apart and a resistance element wound on an annular core 43 is held between them. A boss 13 on the second piece 1<b> carries a lug 14 which fits into a slot 15 in a flange 0 12 in the first piece 1<a>. A radial slot in the piece 1<b> carries a strip 34 making contact with the spindle 4 and connected by a screw passing through the disc with a second strip connected to one end of the resistance - element, the other end of which is connected to an anchoring strip in a groove in the disc 1<a>. A plate 23 connected to the spindle 4 carries a rod 29 on the end of which is a terminal 6. On the rod 29 is an insulating sleeve 30 on which are mounted leaf spring contacts 3 and terminals 7. Lugs on the edge of the discs 1<a>, 1<b> raise the springs 3 from the resistance elements when the apparatus is in the " off " position.