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US 5,129,442 AGranted
Roll-up industrial door having a combined pulley for counterweight and spring tension belts
AssigneeKelley Company, Inc.
InventorRobert J. Warner
Life of this patent
Estimating the term…
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AssigneeKelley Company, Inc.
InventorRobert J. Warner
Estimating the term…
A roll-up door for enclosing the doorway in a building. The door comprises a horizontal rotatable drum mounted above the doorway and a flexible door panel is wound on the drum. A pulley is secured to each end of the drum and the first ends of a pair of belts are secured to each pulley and the belts are wound in overlapping relation on pulley so that adjacent convolutions of each belt are separated by convolutions of the other belt. The free end of one belt is dead-ended on the frame, and a counterbalancing weight is attached to the belt intermediate its ends and exerts a counterbalancing force to wind the door panel on the drum. The free end of the second belt is connected to the lower end of the door panel and a pair of springs are connected to the second belt intermediate its ends and the springs exert a tensioning force to stretch the door panel when the door panel is in the closed position.
A roll-up door construction for enclosing a doorway in a building, comprising rotatable drum means mounted on the building above the doorway, a flexible door panel disposed to be wound on said drum means and adapted to be moved between a rolled-up open position and an unrolled closed position, a first belt having a first end secured to said drum and wound on said drum in a plurality of overlapping convolutions, a second belt having a first end secured to said drum and wound in a plurality of overlapping convolutions, said belts disposed in a common vertical plane and each convolution of said first belt being separated from adjacent convolutions of said first belt by convolutions of said second belt, counterbalancing means attached to said first belt intermediate the ends thereof for exerting a rotational force on said drum means to urge said door panel to the open position, and resilient means connected to said second belt for exerting a downward biasing force on said door panel when said door panel is in the closed position.
A roll-up door construction for enclosing a doorway in a building, comprising a cylindrical drum mounted on the building above the doorway, a pair of annular plates secured in spaced relation to the outer surface of said drum and defining a pulley, a flexible door panel disposed to be wound on said drum and adapted to be moved between a rolled-up open position and an unrolled closed position, a pair of belts each wound in a plurality of overlapping convolutions on said pulley, the convolutions of a first of said belts being separated from adjacent convolutions of said first belt by convolutions of said second belt, each belt having a greater width than thickness, counterbalancing means attached to said first belt for exerting a rotational force on said drum to urge the door panel to the open position, and resilient means connected to said second belt for exerting a downward biasing force on said door panel when the door panel is in the closed position.
A roll-up door construction for enclosing a doorway in a building, comprising a cylindrical rotatable drum mounted on the building above the doorway, a flexible door panel disposed to be wound on said drum and adapted to be moved between a rolled-up open position and an unrolled closed position, a pulley connected to each end of the drum, a pair of belts each having an inner end connected to the pulley and each belt being wound in a plurality of overlapping convolutions on said pulley, each convolution of one of said belts being separated from adjacent convolutions of said one belt by the convolutions of the other belt, counterbalancing means attached to a first of said belts intermediate the ends thereof for exerting a rotational force on the drum to urge said door panel to the open position, and resilient means connected to a second of said belts intermediate the ends thereof for exerting a downward biasing force on the door panel when the door panel is in the closed position.
Dependencies are inferred from the claim text.