Patent GB-363629-A (GB)
Title: Electrical transmission of intelligence
IPC: H04M3/487
Filed: 1930-09-13
Abstract: 363,629. Gramophones. STEIN, S. F., Park Hotel, Williamsport, Pennsylvania, U.S.A. Sept. 13, 1930, No. 27413. [Class 40 (ii).] Audible announcements of the time interspersed with other matter, such as advertisements, are made by using two gramophones one of which gives time announcements at regular intervals whilst the second gives other announcements in the intervals. The apparatus may be used to send announcements to subscribers on manual or automatic exchanges and for wireless transmissions. In the manual exchange system shown in Figs 1 and 2, the line of a subscriber 14 asking for " time " is plugged into jack J of the announcement apparatus, whereupon magnets 18 pull up armatures 20 which are connected by springs 21 to tone arms 15 of the gramophones to place pick-ups 16 on cylindrical records 17. The records are rotated and the tone arms traversed by a common worm shaft and suitable gearing. Each tone arm 15 is pivoted at 40 to a carriage 23 sliding on rods 23a and traversed by a screw 22 engaging a pin 24 on the carriage, the arrangement being such that the tone arm is traversed once in twelve hours. The outputs of the gramophones are directed into microphones 12. When the arm reaches the end of the traverse, the pin 24 is moved up in the carriage by a cam 25 on shaft 22 and is held raised by a spring catch 26 while the carriage is drawn back by a weight W or spring, the catch 26 being released by a projection 28 when the carriage reaches the starting position. During the backward movement, the sound box is raised by de-energizing magnet 18, the circuit of which is opened by a switch 29 operated by engagement of the carriage with a push 30, the switch being re-closed by a push 31 operated through a linkage 32, 33, 34 when the carriage reaches the starting position. As the record is driven relatively fast and the sound box traversed quite slowly, the stylus is lifted from the record, once per revolution, by the engagement of a projection 38 on the cylinder with a cranked lever 37. The record grooves may be helical or circular, and that for the advertisement announcement need only be a single groove if the announcement is to be a name of an advertiser, in which case the tone arm does not need traversing. The tone arm may be spring-mounted on its carriage to give slight lateral play. The traversing mechanism may be driven step-by-step by the clock-controlled switch shown in Fig. 7 in which a clock-driven shaft carries discs 43 .. 46. The discs 43, 44 close circuits for suitable periods for the controlling magnets 18 of the time and advertisement gramophones respectively, and the discs 45, 46 send stepping impulses to the respective traversing mechanisms. The disc 45 impulses a solenoid 47 which, through spring-controlled lever 49 and pawl 51, steps a ratchet wheel 52 secured on the traversing screw. The pivot 50 of the lever may be adjustable to vary the stroke, and a switch 590 may be provided to open the stepping circuit of the " time " mechanism. The mechanism may be stepped forward manually by the lever 49 and moved backward by releasing the pawl and operating a crank pin 58. A similar stepping circuit controlled by disc 46 traverses the advertisement " mechanism, and a switch 59 is provided so that the advertising matter corresponding to a time announcement may be varied.