| 摘要 |
<p>The ratchet-brake for telephone dial centrifugal governors consists of a plastic toothed wheel with a cylindrical reinforcing ring (5). A central hollow cylinder carries a coil spring one end fo which is fixed to a guide plate, the other end being free. The guide plate upper face has claw projections. A detent plate with outer friction edges and inner slots is positioned above the guide plate. The slots engage with projections on a disc fixed to a pinion so that the detent plate is rotated with the shaft. Through rotation of the shaft, the coil spring expands or contracts according to the direction of rotation and the friction drive between the detent plate surfaces and buffers is varied to drive the toothed wheel.</p> |
