Patent GB-327397-A (GB)
Title: Improvements in or relating to sound records and sound recording and reproducing means
IPC: G11B27/06
Filed: 1928-11-28
Abstract: 327,397. Thorogood, R. P., and Good, J. Nov. 28, 1928. Ribbon records and machines. - A ribbon record having the sound trace extending longitudinally forwards and backwards is recorded and reproduced in apparatus which operates automatically to reverse the traverse of the ribbon at each end of its run and to displace laterally the recording or reproducing head to engage the adjacent trace, such head being also movable if desired so that one cutter operates on the ribbon as it is traversed in one direction and another during the reverse travel. The ribbon, which may be formed of celluloid, is provided near its ends, or on strip metal attachments thereto, with projections or shoulders for effecting reversal of the apparatus for driving the ribbon during recording or reproducing. Each longitudinal trace may run into the next one near the end of the ribbon. The ribbon a, Figs. 3 and 4, is traversed between reels c, d and over a drum g, which is driven alternately in opposite directions by friction from guide rolls h, i which are driven through one-way clutches and gears s, s<1> from a gear t on a shaft u driven by a sliding sleeve 6<c> carrying bevel gears 6a, 6b engaged alternately with a gear 6 on a shaft 5 driven from a motor 8 controlled by a centrifugal regulator 8<c>. The reels c, d are driven through friction discs and cords from pulleys 4, 4a mounted on the shaft u and connected therewith by one-way clutches so that the winding-on reel for the time being tends to be driven at a greater speed than the drum g, the other reel being prevented from overrunning by a brake 2<x>. The movement of the sleeve 6<c> to reverse the ribbon traverse is controlled by a lug a<2> near each end of the ribbon acting to rock a bell-crank lever 22, 23, apertured to receive the end of an arm 20 and thereby rock a spindle 19 and an arm 18 carrying pallets 17, 17a acting in conjunction with a toothed disc 16 to constitute an escapement permitting intermittent rotation of a shaft 13 under the action of a coil spring 15, so that through gears 12, 11 a crank pin 10 makes a half-revolution and through link 9 and clutch lever 7 shifts the sleeve 6<c> into one driving position. A link 21 connecting the lever 20 to a corresponding lever 20<a> operated by the projection at the other end of the ribbon effects movement of the sleeve to the other driving position. When the sleeve 6<c> is moved for reversing the travel of the ribbon, pallets 38, 38<a> on the clutch lever 7 permit partial rotation of an escapement wheel 37 on a tubular shaft 33 under the action of a coil spring 36, whereby a screw 32 on this shaft is rotated in a nut fixed to a guided bearing for a journal on the arm carrying the recording head and moves the head laterally to engage the next trace on the ribbon, the head being simultaneously raised by cam sleeve fixed to the wheel 37 and acting on an arm extending from the journal. This journal is also manually adjustable to set the cutter or reproducer in a trace initially. The escapement wheels 16, 37 are driven through one-way clutches from their spindles 13, 33, which can be rotated respectively by finger discs 27, 39 to wind up the coil springs 15, 36 when required. The forward part 29<b> of the arm carrying the recorder is telescopically mounted in the rear part 29 and mav be moved therein by link connection to the lever 20 when the ribbon reverses so as to bring a different cutter into operative position. In a modified arrangement for effecting reversal of movement of the ribbon, the circuit connections to the driving motor 8 are reversed by a switch operated from the lever 20 to reverse the motor.