Winding and anti-drop assembly for door counterbalance system
AssigneeWayne-Dalton Corp.
InventorsWillis Mullet, Gregory Rusnak, John Foreman
Life of this patent
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Abstract
A counterbalance system (25) for a door (D) movable between a closed position and an open position having an axle (20), a cable drum (15) attached to the axle, a winding shaft (35) interconnected with the axle by a counterbalance spring (26), and a pawl (70) selectively movable between a first position for adjusting tension in the counterbalance spring and a second position for preventing rotation of the cable drum upon failure of the counterbalance spring, thereby limiting movement of the door toward the closed position.
Claims23
A counterbalance system for a door movable between a closed position and an open position comprising, an axle, a cable drum rotatable with said axle, a winding shaft interconnected with said axle by a counterbalance spring, and a pawl selectively movable between a first position for adjusting tension in said counterbalance spring and a second position for preventing rotation of said cable drum upon failure of said counterbalance spring, thereby limiting movement of the door toward the closed position.
A counterbalance system for an upwardly acting door comprising, an axle, a cable drum rotatable with said axle, a winding shaft interconnected with said axle by a counterbalance spring, and a combined winding and anti-drop assembly having a dual arm pawl, said dual arm pawl having a first arm selectively interrelating with said winding shaft to adjust the counterbalance forces on the door and a second arm selectively interrelating with said cable drum to prevent rotation of said cable drum and lowering of the door in the event of failure of said counterbalance spring.
A winding and anti-drop assembly for a counterbalance system having an axle, a cable drum rotatable with the axle, a winding shaft interconnected with the axle by a counterbalance spring, and a cable attached to said cable drum and to an upwardly acting door comprising, a first ratchet wheel adapted to rotate with the winding shaft, a second ratchet wheel adapted to rotate with the cable drum, and a pawl selectively engaging said first ratchet wheel to tension the counterbalance spring and selectively engaging said second ratchet wheel to prevent rotation of the cable drum upon failure of the counterbalance spring.
Dependencies are inferred from the claim text.