Patent GB-316706-A (GB)
Title: Process and apparatus for the production of disc records for talking machines
IPC: B29C43/02
Filed: 1928-05-14
Abstract: 316,706. Gramophone Co., Ltd., and Buckle, H. L. T. May 14, 1928. Moulding phonograph records. - Disc records are produced by passing a blank or strip of material between a curved surface co-operating with a second surface so that pressure is applied over a line running across the, blank, e.g. a pair of cylinders one or both of which carries matrices, a pair of oscillating segments, or a curved member co-operating with a flat surface. Fig. 1 shows one form of apparatus in which a strip 8 of cellulose acetate passes from a reel 7 between heating plates 10, 11 and then between an upper cylinder 13 carrying record matrices and a lower plain cylinder 14, the impressed strip passing across a table 48 to a hollow punch 52 where the discs are severed and delivered to a tray 60 and the scrap passed to a take-up reel 53. Each cylinder comprises a central part 15, Fig. 3, and an outer jacket 16 preferably shrunk thereon. The jacket is formed with marginal rims or flanges to receive matrices 18 which are formed upon rectangular backing-plates 19 bent to conform to the cylinder, the matrices being secured in position by strips 20. To form the central apertures in the records, the matrices 18 are furnished with pins 31 adapted to co-operate with dies 32 on the opposite cylinder. Both pins and dies are adjustable by screws 35, 36. The cylinders are rigidly mounted on shafts 24, 23, Fig. 1, the upper shaft being adjustable vertically by screws 45, 46 to adjust the gap between the cylinders and axially in the bearings 39 to ensure correct registration. The cylinders are inter-connected through gears 25, 26, the gear 25 being adjustably secured to the cylinder 13 by bolts 27 passing through slots 28, Fig. 3. The cylinder 13 is heated to soften the material by steam admitted through an axial bore in one end of the shaft 24 communicating through a passage in a spider arm 29 with a circumferential groove on the rear of the jacket 16, the waste steam emerging through a passage 9& leading to an axial bore at the other end of the shaft. The plates 10, 11, Fig. 1, are steam heated and are spaced by members 12 to provide a free passage for the strip 8. The punch 52 comprises a. fixed casing 55 supporting a fixed upper die 58 and a movable hollow die 59 guided within the casing 55 and reciprocated by a toggle 89, 90 actuated by an eccentric 86. A main shaft 64 drives through a worm 71 and worm wheel 72 a shaft 73 carrying the eccentric 86 and a loose gear 74 meshing with a gear 75 engaging the gear 26. The gear 74 is periodically coupled to the shaft 73 bv a clutch controlled by a face cam on the gear 72 and a spring 84 so that the cylinders 13, 24 are stationary during the punching operation. The take up 53 is driven from the shafts 64 through belts 66, 68, 70. Fig. 5 shows a modified apparatus comprising a pair of segments 99, 100 rockable about shafts 101, 102 by links 112, 113 coupled to a slide. The shaft 101 is adjustable vertically and axially. To ensure registration, the lower member 100 is coupled to the link 113 through an adjustable connection 114. During the return movement of the section the shaft 102 is turned in an eccentric bearing by a. hand lever 118 so as to lower the sector 100 to free the strip.