GB440295A - Improvements in programme selectors for telediffusion - Google Patents

Abstract

440,295. Electric signalling systems. FABRIQUES DES MONTRES ZENITH SUCCESSEUR DE FABRIQUES DES MONTRES ZENITH, G. FAVRE-JACOT & CIE, Le Locle, Switzerland. Nov. 29, 1934, No. 34301. Convention date, Dec. 2, 1933. [Class 40 (i)] In an impulse transmitter for selecting programmes in a broadcast distribution system which comprises two rotary discs 5, 7 connected by a tension spring 6, impulses being transmitted during the follow-up movement of the disc 7 after the disc 5 has been set, the discs are alternately locked by a double-ended lever 17 co-operating with notches therein, the disc 5 being normally locked. In operation, depression of the setting knob 4 rocks the lever 17 to release the disc 5 and lock the disc 7 by engagement of a bevelled collar 4<d> with an arm 18, thus allowing the disc 5 to be set by rotation of the knob 4. The disc 7 drives through suitable gearing two cam discs 11, 12 controlling respectively impulse springs 19 and springs 20 which short-circuit the loudspeaker, the movement being controlled by a governor. The normal relative position of the discs is determined by the engagement of studs 15, 16. The knob 4 carries an interchangeable indicator or number plate 28 which is visible through an opening 29. It is arranged that pairs of impulses are transmitted, the programme selector being provided with alternate blank positions, and the cam discs 11, 12 are such that the loudspeaker is cut out from the beginning of the first until the end of the second impulse of each pair. An out of step condition between the impulse transmitter and the programme selector may be corrected by repeated depression of a knob 23 which controls impulse springs 21 in parallel with the springs 19. Specifications 3420/15 and 192,055, [both in Class 40 (i)], are referred to.