| 摘要 |
<p>The device comprises a bed intended to be moved vertically, within a guiding structure, between a low use position and a high storage position. At each corner, the bed carries a pulley 6, 6', 6", 6"' over each of which passes a cord 7, 7', 7", 7"', of which one end is fastened at the top part of the structure. After passing over return pulleys, the free ends of the cords 7, 7', 7", 7"' are fastened to a control handle 9 equipped with a counterweight 21. The step-down hoists formed by the pulleys 6, 6', 6", 6"' and the cords 7, 7', 7", 7"' make it possible to use a counterweight 21 which has a mass substantially less than that of the bed. <IMAGE></p> |
