Patent GB-231123-A (GB)
Title: Process and means for the recording of sound on blank discs, cylinders, endless bands or ribbons
IPC: G11B3/08
Filed: 1924-09-29
Abstract: 231,123. Nightingall, V. C. J. March 20, 1924, [Convention date]. Tool-arms and mounting; feed-motions; records, blanks for.-Single serviceable. records of sounds are directly cut in hard material by employing a heated stylus and a record material, such as celluloid or casein or a mixture of these, which has the property of being softened locally by the heated stylus sufficiently to permit the cutting of the track and of hardening again almost immediately. The blank may be of disc, cylinder or ribbon form and may be built up of layers of the record material or a strawboard or papier mache core, a black dye being added to conduct heat rays directed on the blank during cutting to the cutting point. Fig. 7 shows a machine for cutting a disc record 5 in which a tone-arm carrying a sound box fitted with an electrically heated stylus is moved. across the rotating disc by a weighted cord 27. its movement being controlled by a cord 21 passing to a part-nut member 18 engaging a screwthreaded spindle 17 driven from the turntable shaft 10 which is driven bv a motor 13a. The stylus is constructed with two limbs 36, 38, Fig. 3. reduced and connected at the cutting point 40 so as to be heated to about 1000‹ F. bv an electric current suitably led to sockets 37, 41 for the stylus limbs, the socket 41 being insulated from the stylus bar 35 by a mica washers. The recorder works within the cover 26a of the apparatus, and a lamp 26b or other heating means may be arranged within the cover to supply heat rays to the blank, the black dye in which facilitates conduction to the cutting point. Fig. 6 shows a circuit lay out for driving the motor 13a and heating the stylus wherein the supply mains 51, 50 have a switch 52, and a shunt therefrom acting through a transformer 55 and connections 58, 59 to heat the stylus 57 and having a switch 56, this arrangement preventing heating of the stylus, even though the switch 56 is closed, except when the switch 52 of the motor-driving circuit is closed. The Specification as open to inspection under Sect. 91 (3) (a) describes also apparatus in which sounds or signals to be recorded are converted into current fluctuations and transferred by wire or wireless telephony or telegraphy to the stylus, the fluctuating current being passed through a coil connected to the stylus mounting and arranged in a magnetic field whereby the stylus is vibrated in accordance with the current fluctuations due to the sound or signal. Fig. 8 (Cancelled) shows an arrangement in which sounds or signals from a distant source are converted into current fluctuations and connected by a lead 58 to the grid of a thermionic valve 60 and the amplified current on the plate circuit is passed through pancake coils 64, 65 to influence a similar coil 66 through which a constant current supplied by a battery 69 passes. The movements of the coil 66 are transmitted through a lever and a bridge 70a to the stylus 71 which is in a circuit with a heating battery 76. This subject-matter does not appear in the Specification as accepted.