GB714748A - Improvements in or relating to electric recording and reproducing apparatus - Google Patents

Abstract

714,748. Driving sound film, tape or wire. TRUVOX, Ltd. May 28, 1953 [June 27, 1952], No. 16282/52. Class 40 (2). In a recording and reproducing apparatus for a record medium such as magnetic wire or tape in which electric motors of the eddycurrent or shaded pole type are used to drive each reel to take up the medium, braking is provided by supplying a direct current to the motor which is employed for driving in the opposite direction to that which the medium is being moved at the time of braking. The figure shows a general arrangement in which a take-up motor 32, a capstan motor 23 and a rewind motor 37 are connected to an alternating current supply through push-button switches 38, 39, 40. The operation of any one of these switches, or of " stop " button 49, automatically releases whichever of the others may be at the time in the operative position. The switch 38 serves to connect motor 23 for a record/reproduce operation and at the same time to connect motor 32 through a resistance 63 to effect a weak energisation of the motor 32 for winding the medium on to reel 13. Operation of switch 39 effects a fast-forward winding of the tape by coupling the motor 32 direct to the alternating current supply, during which operation the medium is not in engagement with the capstan 16. Similarly, switch 40, couples motor 37 for a fast-rewind operation. A switch 43 is also provided which when operated does not release the other switches but couples a direct current source to whichever motor 32 or 37 is not at the time connected to the alternating current source, and thereby produces a braking effect. The brake switch 43 and "stop" button 49 are coupled together by a spring-loaded cam-operated detent 22 so that the "stop " button cannot be operated unless the brake switch 43 is being pressed.