| 摘要 |
1,071,335. Making gramophone records. DECCA Ltd. Aug. 26, 1964 [Sept. 16, 1963], No. 36328/63. Heading B5A. In a method of making a gramophone record, a pre-formed blank, i.e. a blank requiring only a sound track to be embossed thereon to complete manufacture, is fed to an embossing press as described in Specification 1,071,333 and is centred with respect to the dies thereof by means of a pin 28 which passes through the spindle hole of the blank. The pin 28 is integral with a double acting air operated piston 26 and is moved by admission of air to a cylinder 32, 35 formed in a bushing 27 fixed centrally of one die assembly. In operation, a disc is held in approximate position between the dies, the tapered end 31 of the pin 28 is urged through the spindle hole to centre the disc, and on continued movement, the pin enters a second bushing 23 fixed centrally of the other die assembly and causes, by feed of air through a bleed passage 29, operation of a switch 43 and hence closure of the dies. The pin 28 is automatically retracted before the dies are opened. Since movement of the dies occurs subsequent to the operation of switch 43, no action occurs if pin 28 fails to pass through the spindle hole of a disc.
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