| 摘要 |
1,025,462. Centre-post gramophone recordchangers. H. C. HANSEN. Aug. 30, 1962 [Aug. 31, 1961], No. 31382/61. Heading G5R. The prongs 10 and wedges 16, Fig. 1, supporting the record stack are separately actuated by a reciprocating tube 20 and a reciprocating rod 22, respectively and means are provided by which the prongs 10 cannot be retracted until the wedges 16 are holding all but the bottom record of the stack. A cycling disc 56 operates the actuators 20, 22 via knee-action members 68, 76 as detailed in Specification 954,291 and both of these members must necessarily make horizontal movements in slots 82, 84, Fig. 5, before they can make the operative vertical movements, the timing tracks on the cam disc 56, Fig. 2, being appropriately phased. The wedge support, Fig. 4, is allowed some lost movement by the centre-post implosions 34, as seen by the two halves of Fig. 6, to allow the wedges to find the space between the two lowest records. The lowermost record of the stack is lowered somewhat clear of the stack so that the pick-up arm can be swung across to gauge its diameter as in Specification 862,004, the remainder of the pick-up movement and control being as in Specifications 852,061 and 852,064. Switch-off means as in Specification 859,392 may also be incorporated. The speed-control mechanism may be associated with the record-changing mechanism to retract the prongs 10 at certain selected speeds for use as a single-record player as in Specification 1,025,461. Instead of the knee-action links, an alternative embodiment 'uses the slotted rocker 209, Figs. 11 and 12. |
