| 摘要 |
719,643. Gramophones. BIRMINGHAM SOUND REPRODUCERS, Ltd., GUEST, L. V., and SHEPHARD, P. V. Jan. 12, 1953 [Jan. 28, 1952; July 16, 1952], Nos. 2338/52 and 18002 / 52. Class 40 (2). In an automatic gramophone the frictional forces tending to sweep the pick-up inwards at the start of a record is countered by the use of yieldable spring biasing means which acts in opposition the movement of the pick-up during the earlier part of its traverse across the record, but becomes progressively reduced until at the end of the. record the direction of the biasing may be reversed. The invention may be used in an automatic gramophone of the kind described in Specification 693,594. A spring 66 is mounted on a member 56 which is stationary during the playing of a record, the end of the spring resting in and acting on an arm 68 on a member 25 carrying the pick-up arm. As the member 25 rotates clockwise during the playing of the record, a dead centre is eventually passed, Fig. 4, after which the spring 66 assists the inward movement of the pick-up arm. A gravity biasing means may be employed in which a weight pivotally connected with the pick-up arm is drawn up an inclined surface during the tracking of the stylus, the inclined surface being made of varying gradient and finally terminating in a gradient of opposite slope.
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