| 摘要 |
<p>1300320 Up and over door OVERHEAD DOOR CORP 30 Sept 1970 [1 Oct 1969] 46464/70 Heading E2M An up and over door operating mechanism, as shown, comprises rails 48, 49 which support a carriage 57 which moves along the rails, the carriage also being attached to the upper edge of door 10 by bracket 66. The lower edge of the door is attached to cables 38 (39 not shown) which are attached to shafts (26, 27 not shown) respectively on the spring counterbalancing mechanism 24. A differential driving mechanism is connected between the carriage 57 and the shaft, which automatically adjusts the movement of the cables and the carriage to compensate for the differing speeds of the upper and lower edges of the door.</p> |
