Lift assembly systems and methods
AssigneeElectronic Theatre Controls, Inc.
InventorDonald A. Hoffend, III
Life of this patent
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Abstract
A lift assembly system and method can include: a funnel-shaped drum having a constant diameter portion and a gradually increasing diameter portion; a cable management system adapted to position a cable in a single layer in a tray; a beam clamp tube receiver adapted to allow a tube to slide relative to a beam and be secured to the beam; a cable keeper and a slack line detector adapted to maintain cables in position about a drum upon loss of cable tension; a horizontally oriented low profile cable adjuster adapted to adjust the length of a cable; an overspeed braking mechanism; a fleet pivot arm pivotable on the end of a tube so as to guide cables along a desired fleet angle; and/or a pull-type load sensor connected between a tube and a drum adapted to sense changes in a load force and adjust movement of a load.
Claims14
A lift system configured to lift an article, the lift system comprising:
- a plurality of cables including a first cable and a second cable;
- a drive mechanism;
- a funnel-shaped drum including,
- an apex having a first diameter,
- a base having a second diameter larger than the first diameter,
- a constant diameter portion having the first diameter and extending from the apex, and
- a gradually increasing diameter portion extending from the constant diameter portion to the base,
- wherein the drum is adapted to wind and unwind the plurality of cables about the drum to raise and lower the article attached to the plurality of cables such that the first and second cables wind about the constant diameter portion of the drum and the gradually increasing diameter portion of the drum so that coils of the first cable are at least partially covered with coils of the second cable as the plurality of cables wind about the drum.
A method of operating a lift system comprising:
- providing a drum having a constant diameter portion and an increasing diameter portion;
- and
- winding a plurality of cables about the drum to raise an article attached to the plurality of cables,
- wherein winding the plurality of cables about the drum includes moving a first cable of the plurality of cables from the constant diameter portion of the drum onto the increasing diameter portion of the drum and moving a second cable of the plurality of cables from the constant diameter portion of the drum onto the increasing diameter portion of the drum so that coils of the first cable are at least partially covered with coils of the second cable as the plurality of cable wind about the drum.
Dependencies are inferred from the claim text.