| 摘要 |
<p>A display (12) comprises a curtain carrying a series of visual messages, stretched between two rollers (5, 9) around which it is wound, the rollers being rotatably mounted in parallel in a frame (1), and a synchronous drive mechanism (18) for the two rollers. The drive mechanism comprises a toothed belt or chain (21) driven by a motor (19) and interacting with a first toothed pulley (22) which is keyed in rotation on the first roller (5) and a second toothed pulley (23) mounted idly on the second roller (9) to which it is connected by elastic means (25) which compensate the curtain tension as a function of the varying diameter of the roller caused by the winding of the curtain. <IMAGE></p> |
