Abstract: A cable-wound drum style hoist with a rotating shaft supported by bearings that has both: (i) some freedom of motion in (at least) one of the bearings; and (ii) a pillow block in the shaft to impart some freedom of motion (beyond freedom to rotate about the central axis) in the shaft itself. By allowing some freedom of motion both the bearing(s) and the shaft, the hoist can better accommodate for bent shafts and/or slight misalignment of coaxial bearings. Also, a set of preferred connection hardware for mechanically connecting a hoist reducer box to a hoist backbone with preferred degrees of freedom/constraint.

Abstract: A failsafe brake is provided for preventing the uncontrolled descent of a counterweight arbor or stage equipment load in a counterweight rigging systems. Specifically provided is a failsafe brake according to which a brake shoe is biased to contact a counterweight arbor guide rail and grip it between the brake shoe and a backer plate, except when tension is applied to a line to move the counterweight arbor.

Abstract: The invention is a compact drive for a counterweight-assisted winch which can be retrofitted into existing manually operated systems that use counterbalancing weights. The counterbalancing weight will be fixed at a first predetermined percentage of the maximum capacity of the set, preferably about 50%. The winch is rated at a second predetermined percentage of the maximum capacity of the set, preferably about 50%. Together the first and second predetermined percentages sum to at least 100% of the maximum capacity of the set. By using the winch in a closed loop configuration, it will operate the set at any load from 0 to 100% of the set's rated capacity, without the need to adjust the counterbalancing weights. The compact drive system employs two motorized winches positioned along the long axis of two adjacent counterweight rigging systems, each winch engaging a respective chain used to move a counterbalancing weight.

Abstract: A theater rigging assembly having a beam, which is attached to structural support members of a theater or other performing arts venue. The assembly further includes a winch assembly and head block that can be positioned at any point along the beam and selectively fixed in position. The winch portion includes cables for raising and lowering battens or other loads. The head block includes head sheaves, which redirect the cables to loft sheaves that are selectively attached to the beam. The head sheaves are diagonally displaced to separate the cables. The winch portion includes a motor, a gear box, a drum and a brake. The brake includes a ratchet and two brake disks. It uses at least one friction surface that contacts at least one of the brake disks to cause a pawl to engage or disengage from the ratchet.