| 摘要 |
<p>The device has a roller fixed on a base plate, and a joint comprising two pulleys that are assembled on flanges by axes. A control hand lever brings together a cam, return spring, an anti-panic safety pin and an anti-panic spring. The cam is connected to the lever by its rotation, where the cam presses on the flanges supporting the pulleys to reduce the pressure of the cord on the pulley and the adherence of the cord. The cord slides on the roller, where speed of the sliding is proportional to a space of the cord for passing between the pulley and roller.</p> |
