| 摘要 |
<p>A manual tuning shaft and treadle bar drive shaft coupling and decoupling mechanism in a pushbutton radio tuner includes a one piece manual tuning shaft and a crown gear mounted on the drive shaft for rotation thereon. A pinion gear on the tuning shaft engages the crown gear to drive the latter rotatably on the drive shaft. The crown gear includes a high friction clutch surface. A second high friction clutch member is also mounted on the drive shaft for rotation thereon and a flexible metal disc is mounted on and attached to the drive shaft for rotation therewith. The disc is located between the crown gear and second clutch member. A declutch bar of the tuner engages the second clutch member and biases the latter into engagement with the flexible disc forcing the disc into driving engagement with the high friction surface of the crown gear. Rotation of the manual tuning shaft then rotates the drive shaft. Movement of the declutch bar against the biasing force upon depression of a pushbutton in the radio tuner disengages the clutch member, flexible disc and crown gear to decouple the manual tuning and drive shafts.</p> |
