| 摘要 |
An acoustic playback device includes a plurality of selector bars equal to the number of recording grooves, a plurality of biased stylus-pressure releasing bars, the bars moving against the force of the associated spring as the corresponding selector bar is pushed into engagement with a stopper pin on the record disc to bring the introductory portion of the selected recording groove to a position where it can be engaged by a pickup. A latch plate is axially spaced from the reverse side of the record disc unit. An annular vertical wall is formed on the surface of the latch plate facing the record disc unit. Hooks on the stylus-pressure releasing bars engage the vertical wall when the stylus-pressure releasing bars are moved forward. Stylus-pressure releasing portions formed on the ends of the stylus-pressure releasing bars engage the stopper pin when advanced with the stylus-pressure releasing bars. Cam surfaces on the stylus-pressure releasing portions and the stopper pin cause the record disc to disengage the hook of the stylus-pressure releasing bar from the vertical wall and permit return movement of the stylus-pressure releasing bars. Tapered surfaces between the stylus-pressure releasing bars and the peripheral edge of the latch plate create a cam action such that a forward movement of the stylus-pressure releasing bar against the force of the spring causes the latch plate with the record disc unit to move away from the sound transmitting plate.
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