GB370418A - Improvements relating to sound recording apparatus - Google Patents

Abstract

370,418. Recording sound. COLE, Ltd., E. K., Ekco Works, Southend-on-Sea, KNIPE, A. R., 5, Southsea Avenue, and MARTIN, A. W., 1, Thames Close, both in Leigh-on-Sea. Jan. 2, 1931, No. 214. [Class 40 (ii).] In sound-recording apparatus of the kind in which a recorder is traversed across a blank disc on a turntable by means of a screwthreaded spindle mounted in a frame and driven by a friction wheel engaging the turntable or disc, a driving blade attached to the recorder or to the support therefor is constructed as or mounted on a resilient metal strip, which is adapted to engage with the screw-thread in such a manner that the weight of the recording device imposes no considerable load on the spindle, but is borne wholly or mainly by the frame or the disc. The apparatus shown in Figs. 2 and 4, adapted for attachment to an ordinary gramophone, comprises a frame formed by two end-pieces 5, 9 supporting a screwed spindle 13 and a rod 8, the part 5 having a socket 6 which fits loosely over the turntable spindle, while the other end-piece consists of a yoke 9 pivoted at 10 to a pin 11, which is pivotally mounted in a socket member 12 on the motor-board. The spindle 13 is carried on bearings 14, and is rotated by gears 16, 17 and a friction-wheel 18, the latter being mounted on the member 5, so as to be in contact with the record disc 4 on the turntable. The recorder 21, which is an electromagnetic device adapted to be connected to a suitable circuit in a wireless receiver or microphone apparatus, is connected by plug and socket contacts 22 to a carriage 20, which is slidably mounted on the rod 8. The carriage is provided with a driving blade 25 formed as a resilient metal strip which engages laterally with the screw thread of the spindle 13. The pitch of the spiral trace formed by the recorder can be varied by providing arrangements for adjusting the position of the driving wheel 18 relatively to the turntable spindle. This wheel carries a tyre 19, and the portion of the record blank engaged thereby may be roughened. Fig. 7 shows a modification in which the recorder 33 is mounted on an ordinary gramophone tone-arm 34. The driving blade 25, engaging with the feed-screw 13, is in this case mounted on or formed as the end of a resilient arm, which is adjustably mounted on the tone-arm by a clamp 38. The spindle 13 is supported by a frame 35, one end of which is mounted in trunnions 36, the other end being adapted to fit over the turntable spindle (not shown). The friction wheel 18 may be mounted, as shown, directly on the spindle 1.3. In order to reproduce from records made by the apparatus shown in Fig. 2, the feed mechanism for the recording device may be removed by withdrawing the pin 11 from its socket, and a bracket 27 pivotally supporting an arm 26 for carrying the device 21 may be substituted as shown in Fig. 5, a fibre needle 32 being then used to enable the device 21 to serve as a pick-up. Terminals 31 are connected through plug and socket contacts 29 and a cable 28 to the pin and socket contacts 22 on the pick-up.