| 摘要 |
<p>The system has a winding coil separate from the locking mechanism, the coil maintaining the belt constantly under tension and being controlled by a spring. The locking mechanism is formed by two pins fixed in position and non-rotating and a third pin moving in the housing grooves. Pulling gently on the belt allows it to be unwound, the top pin being held in a notch, but a harder pull frees the pin from the notch so as to lock the belt, while relaxation of tension allows springs to return the pin to the notch. The coil and the locking mechanism, which acts on the belt and not the coil, are accommodated in the same housing. A coil spring can be used to wind the belt in.</p> |
