| 摘要 |
<p>In a timepiece movement, more particularly a quartz wrist watch movement, having a low-torque stepping motor, there is provided a differential mechanism which drives the hands and makes it possible to move the hour-hand alone in jumps. A cannon-pinion having a toothing acts as a sun gear. A planet gear is mounted on an hour-wheel which acts as a planet carrier. A ring gear takes the form of an annulus having internal teeth which is normally stationary but is controlled by a stem and can be rotated by jumps to cause the planet gear to roll along the cannon-pinion toothing, thus causing the planet carrier and consequently the hour hand to jump.</p> |
