winding and anti-drop assembly for door counterbalance system
AssigneeWayne-Dalton Corp.
InventorsWillis J. Mullet, Gregory M. 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.
Claims24
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, a first ratchet wheel operatively interconnected to said winding shaft, a second ratchet wheel operatively interconnected to said axle and a pawl selectively movable between a first position, contacting said first ratchet wheel, for adjusting tension in said counterbalance spring and a second position, contacting said second ratchet wheel, 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 pawi having a first arm selectively interrelating with a first notched element coupled to said winding shaft to adjust the counterbalance forces on the door and a second arm selectively interrelating with a second notched element coupled to 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, wherein said second ratchet wheel rotates independently of said first ratchet wheel.
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, a first ratchet wheel connected to said winding shaft, a second ratchet wheel connected to said axle and a pawl movable between a first position, contacting said first ratchet wheel, and a second position, contacting said second ratchet wheel, a spring having a fixed leg and a movable leg engaging a locator on said pawl, said locator being a slot, wherein said movable leg of said spring is selectively positioned at one end of said slot to urge said pawl toward said first position and at the other end of said slot to urge said pawl toward said second position.
Dependencies are inferred from the claim text.