GB759253A - Improvements in or relating to sound recording and sound reproducing apparatus - Google Patents

Abstract

759,253. Magnetic sound recording and reproducing apparatus. PROTONA PRODUKTIONSGES FUR ELEKTRO - AKUSTISCHE GERAT GES. Jan. 1, 1952 [Jan. 2, 1951; Aug. 29, 1951; Oct. 27, 1951], No. 94/52. Class 40(2) A small magnetic recorder comprsies spools 11, 12 between which a thin wire 15 is drawn over a transducer 13 and a pivoted magnet 14 acting as an erase head. The spools are driven from a resiliently mounted motor 17 through a worm 20 which can be swung by a lever 24 to'engage either of pinions 21, 22. Movement of the lever 24 also causes members 26 or 27 to brake either of the corresponding pinions 21, 22 in such a manner that the spool which acts as the supply spool is always braked during reeling. The take-up spool 12 is heavier than the supply spool 11. A brake 25 acts on the spool 12, when the lever 24 is in a neutral mid position. A further brake 34 acts on the spool 12 on operation of a master switch 7, and comes into operation before the switch 7 stops the motor. A gear 79 is provided to enable the wire to be rewound at a high speed. A centrifugal regulator 39 having a braking disc 43 engaging a brake 42 adjustably positioned by a screw 40 is provided to adjust the speed of the spools. The transducer is mounted on a pivoted carrier 44 which is oscillated by a heart-shaped cam 48 to provide a levelwind arrangement. A pivoted bridge 56 prevents the wire from jumping off the transducer. The recording time is indicated by a meter driven from the spool 12 by a magnetic coupling 74. The amplifier and the spools and gearing are formed as independent removable units. Batteries 2, 3 and 4, 5 are provided for the motor, and the amplifier, respectively. A plug 6 is provided to allow a mains supply to be connected.