Method and apparatus to raise and lower an overhead door

摘要

A method and apparatus to raise and lower an overhead door comprising a lift mechanism, a master pulley block, a fixed pulley mounted to the lift mechanism, a plurality of guide sheaves each associated and spaced from with the master pulley block and supported by the elongated support member, and a plurality of cables each having two opposing ends and passing over the fixed pulley and the master pulley block and further passing over an associated one of the plurality of guide sheaves, wherein each cable of the plurality of cables attaches by attachment means to an overhead door.

主权项

1. An apparatus to raise and lower an overhead door comprising:
A single lift mechanism to provide all force needed to fully raise said overhead door from a lowered position, wherein said lift mechanism is positioned to a side of said overhead door; A single master pulley block; a pulley mounted to said lift mechanism, and in association with said master pulley block; a plurality of guide sheaves, each of said plurality of guide sheaves associated with said master pulley block and supported by an elongated support member, each of said guide sheaves being spaced from said master pulley block; and a plurality of cables, each of said cables having a first and a second opposed end and passing from said first end at a first attachment point around said pulley attached to said lift mechanism and passing to and around said master pulley block, after which each cable passes over a separate associated one of said plurality of guide sheaves, thereby distributing each of said plurality of cables along the length of said support member, wherein each cable of said plurality of cables attaches at said second end by attachment means to an overhead door at multiple points along the door in order to distribute the lifting force evenly along the door.