| 摘要 |
<p>A limit controlling and positioning structure for use in transmission of a roller door comprises a clutch 2, transmission gears 4 transmission main shaft 3, and an inductance pedometer 5. The components, for example, the transmission gears 4, inductance pedometer 5 etc., may be mounted directly on the driving motor 1. The inductance pedometer is used to count the number of revolutions and hence determine the door position.</p> |
