| 摘要 |
<p>The door has a tilting apron (1) that is guided vertically in its lower part in rails (2a, 2b). A balancing device (6) has a counterweight (61) connected to a beam by a hinge (63). Bottom corners (11a, 11b) of the apron are connected to the common counterweight by cables (3a, 3b) passing over pulleys (4a, 4b), respectively. Ends (64a, 64b) of the beam are connected to the respective cables. The cables are chosen from belts, notched belts, chains, and straps. The pulleys are chosen from rope pulleys, belt/strap pulleys, and chain pulleys.</p> |
