| 摘要 |
A controllable drive for a tape recorder including a toothed wheel having first and second toothed portions, first and second hiatus portions and a cam surface. The toothed portions are arranged to engage a drive gear, whereas the hiatus portions do not engage the drive gear. A link is disposed for angular movement and is driven by the cam surface. A spring urges the link against the cam. A locking mechanism is provided to lock the toothed wheel in a first position whereat one of the hiatus portions is adjacent to the drive wheel and a second position whereat the other hiatus portion is adjacent the drive wheel. When unlocked from its second position, the link, under action of the spring, urges the toothed wheel in a first direction until the first toothed portion engages the drive wheel. Thereafter, the drive gear drives the toothed wheel until the first position is reached whereat the drive wheel is again locked. The cam surface is shaped such that after the drive gear engages the first toothed portion, the cam surface angularly moves the link against the action of the spring. The hiatus portion associated with the first position is sufficiently wide such that upon being unlocked from the first position, the wheel freely rotates a major portion of the distance to the second position until the second toothed portion engages the drive gear and provides a breaking action to the free rotation. The free rotation occurs in response to the link acting against the cam surface under the urging of the spring. As the wheel is slowed by the second toothed portion, it is rotated in response to rotation of the drive gear to the hiatus associated with the aforementioned first position.
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