GB400526A - A loudspeaker change-over switch, especially for radio distributing apparatus - Google Patents

Abstract

400,526. Mechanical switches without quick-action; regulating-switches. NAAMLOOZE VENNOOTSCHAP HEYBROEK'S GROOTHANDEL, 244, Keizergracht, Amsterdam. April 13, 1933, No. 11035. Convention date, July 28, 1932. [Class 38 (v).] In a radio distributing system a change-over switch for connecting a loud-speaker to any one of six programmes comprises a base portion 7 on which are mounted an inner ring of six diametrically opposed pairs of contacts 1,1 .. 6, 6 each having a corresponding contact 16 or 17 on an outer ring. All the outer contacts 16 are connected together and to a terminal 19 which is connected by a plug 21, clip 22 and fuse (not shown) to a loud-speaker terminal 24. The contacts 17 are similarly connected to the second loud-speaker terminal 25. Between the cover 8 and base 7 is mounted a rotatable ring 9 carrying a pair of diametrically opposite contact rollers 29 adapted to bridge adjacent pairs of contact springs 14 attached to the inner and outer rings of contacts. Thus if the six pairs of incoming leads are connected respectively to opposite pairs of inner contacts, rotation of the ring will connect the loud-speaker to each pair of leads in turn. A spring-pressed ball (not shown) engages recesses 34 on the ring 9 to locate the switch in each of its operative and inoperative positions. In the modification shown in Fig. 6, a volume control is mounted on the cover. This consists of a reactance or resistance 48, one end of which is connected through a central bolt 44 to one of the loudspeaker terminals. Tappings are taken to a series of contacts 49 arranged in a circle so that on rotation of the knob 43 the contacts 49 successively engage a ball 57 connected by a spring 58 to the second loud-speaker terminal.