Patent GB-808848-A (GB)
Title: Improvements in or relating to sound recording and reproducing apparatus
IPC: G11B5/00
Filed: 1956-02-14
Abstract: 808,848. Magnetic recording and reproducing apparatus. MARSAN, A. A. Feb. 14, 1956 [Feb. 16, 1955], No. 4535/56. Class 40 (2). A battery-operated portable miniature sound record apparatus is provided with a recording unit 9 comprising a magnetic head 23, a driving motor, spools 24, 25 wtih magnetic wire 26 and a reversible drive therefor, which unit is insertable into a larger common housing 1 containing a power supply 12, loud-speaker 14 and an auxiliary amplifier 13 for said loud-speaker 14. The detachable unit 9 is arranged in a case 10 insertable into the housing 1 and having control buttons and knobs accessible through an open space 5. Lateral contact springs or plug connections establish electrical connection with the other parts of the apparatus, including the loud-speaker 14, the power supply unit 12, auxiliary amplifier 13 and a telephone adapter 15. A radio receiver may also be incorporated and may be connected in place of the recording unit direct to the auxiliary amplifier. Hightension and heater batteries 18, respectively, are contained in the casing 10 of the detachable unit, as is a revolution counter 20 visible through a window 7 in the cover 2 of the main housing 1. A second window 8 may be provided to allow observation of further indication means on the face of the upper spool. Jacks are provided for the connection of microphone and headphones, audio strength of the latter being controlled by knob 16, and the strength of the loud-speaker by knob 17. The telephone adapter 15 is arranged, by means not shown, to lift the telephone cradle and record the voice of a calling subscriber or reproduce to the subscriber a pre-recorded message. The magnetic head 23 serves to record, reproduce and erase. The spools 24, 25 are mounted coaxially, the upper spool 24 being arranged as a supply spool and clamped by a milled nut 27 to an inner shaft 28, and the lower spool 25 arranged as a take-up spool secured to an outer shaft 32. The shafts 28, 32, respectively, carry toothed wheels 44, 34 coupled to wheels 45, 41 of a reversible drive, the shaft 40, Fig. 10, of which is reversed according to whether a forward or rewind operation is taking place. Finger pressure on control 33 on a control rod 37 moves a fork to the dotted position shown in Fig. 8 and allows a grooved clutch member 35, splined on shaft 40, to be moved by spring 43 in engagement with wheel 41 to establish a forward drive, while the operation of a further button, not shown, reverses the motor and returns the control 33 to the full-line position in Fig. 8 so that a reverse drive is effected through a freewheel device 46, containing balls 47 acting on slant surfaces, establishing a positive drive on shaft 28, and thereby returning wire to spool 24. The control rod 37 carries conical members 49 which act on brake members 57, 58 to apply a braking pressure on whichever spool is having wire removed from it. Level winding on the spools is effected by guide members 59, 59<SP>1</SP> which are oscillated transversely by cams 64, 65 moved by the main drive of the apparatus.