| 摘要 |
An apparatus for counterbalancing an overhead door includes a spring anchor assembly adapted to be connected between one end of a torsion spring and a wall of a building at an overhead door opening and a spring winding assembly adapted to be connected between the opposite end of a torsion spring and a shaft rotatably mounted on the wall and coaxial with the spring. The shaft carries a pair of winding drums attached by cables to the bottom of an overhead door. Both the spring anchor assembly and the spring winding assembly have spring attachment means which are adjustable to accommodate different diameters of torsion springs and compensate for the helical form of the spring.
|
