| 摘要 |
<p>A bottom scrolling sign has a sign face member (16) with windows (20) in which indicia appear. A framework (28) is mounted proximate the interior surface of the sign face member. A pair of shafts (48, 60) are mounted on the framework to contain a plurality of web rolls (58) between which webs (64) containing indicia extend. Guide (66) means adjacent the windows guide the web and prevent light leaks. The guide means (66) is so formed as to avoid shadows on the sign face member. A drive mechanism (40) simultaneously rotates the shafts (48, 60). Clutches (90), interposed between the web rolls (58) and the shafts (48, 60), are selectively operable to move the webs (64) in one or the other direction across the window to alter the displayed indicia. A constantly applied differential brake (105) is also coupled to said web rolls to maintain tension on the webs and to assist in their movement.</p> |
