Change-over device on dictating machines

摘要

844,047. Magnetic recording and reproducing apparatus. ASSMANN G.m.b.H., W. April 6, 1959 [April 11, 1958], No. 11620/59. Class 40 (2). In order to avoid accidental erasure in a dictation machine, means for initiating the raising and return movement of the sound head are mechanically coupled with an electrical change-over circuit, whereby a back-spacing operation causes the machine to be switched to a non-record setting. Downward pressure on a control knob depresses one end of a cranked lever 6 to lift the sound arm 5 and to break a switch 7 which thereby causes the hold-on circuit 11 of a relay 9 to be broken to effect a disconnection in the supply circuit 10, until restored by the operation of a push switch 12.