Abstract: A hoist system with an overspeed detection sub-system for detecting overspeed by comparing an actual drum assembly speed with a target value. For example, the rotation of a motor may be determined by a first rotary encoder and the rotation of a drum may be determined by a second rotary encoder. The output of the first rotary encoder (the basis of a target value) is compared with the output of the second rotary encoder (corresponding to actual motion of the drum). If the difference between the target value and the actual motion is too large, then a problem, such as a broken hoist hardware component may exist, and appropriate remedial action is taken, such as braking the motor and/or the drum.

Abstract: A winch system with a force cable that transmits electrical current and/or digital data to the load. For example, the force cable, including a power line and/or a signal line and includes at least: (i) a first portion extending from the load to the drum; and (ii) a second portion that is wound around the drum. If there is a power line in the force cable it is electrically connected to an electrical commutator by a rotating current path. If there is a signal line in the force cable it is connected in data communication to a data signal commutator by a rotating communication path. The commutator also has an input for receiving electrical current and/or digital data, as appropriate. The commutator transmits the electrical current and/or digital data from its input to the rotating current path and/or communication path. The drum defines an axial channel extending from at least one end of the drum along its axial direction, and current path(s) and/or communication path(s) are routed through the channel.

Abstract: A system and/or method for recognizing a theatre donation by placing a notice on a locking rail sub-system in a theatre. This system and/or method is believed to be rather counterintuitive because the locking rail is generally a low visibility part of the theatre, where the general public does not traditionally go. Despite this low visibility, the present invention is believed to foster a surprisingly large amount of goodwill, the relatively low visibility of the locking rail assembly notwithstanding. Also, because the locking rail is such a critical piece of equipment for safety purposes, the present invention recognizes that the good associations with donors and/or donations will tend to be subtly and psychologically enhanced by the fact that the donation related information is placed on the locking rail assembly.

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 system for suspending a vertical curtain (especially a theatrical curtain) and for driving the curtain to move horizontally (for example, between a position covering a stage and a position not covering a stage). The curtain is suspended directly from a drive chain, along at least a portion of the drive chain, by chain attachment structures. Also, a rotating switch that can be actuated by a switch attachment structure supported by the drive chain. Also, the use of a dedicated encoder sprocket which is separate from the guide sprockets.

Abstract: Rigging calculation software for performing rigging calculations. Preferably, the rigging calculations include the ability to calculate one or more of the following: fleet angle; offset, distance, fleet angle, electrical motor characteristics, recommended sheave pitch; load line capacity; batten capacity; and/or electric motor characteristics. In some preferred embodiments the rigging calculation software is designed to do calculations especially tailored for the design and/or installation of theatrical rigging systems. In some preferred embodiments the rigging calculation software may be accessed over a communication network wirelessly through the internet.

Abstract: A lift system having a modular backbone with two or more backbone sections being attached end to end to form the backbone. Also, a lift system with end to end modular attachment, using universal joints, between motor assembly(ies), shaft section(s), drum assembly(ies) and/or shaft end sections. Also, a lift assembly with a backbone having longitudinally adjustable lift component attachment hardware, such as an elongated slot with lips suitable for engaging a nut tooth.

Abstract: The present invention discloses a drive system for theatrical rigging, comprising a drive rope and a drive pulley. The drive rope has a fiber or cable core, surrounded by a plastic jacket. Formed on or in the surface of the drive rope are traction features that engage corresponding grooves in the drive pulley.

Abstract: The present invention is directed to a mounting member for use in a pulley assembly that is generally U-shaped and includes: (i) a side wall portion; (ii) a base portion; and (iii) a stiffness enhancement portion. The side wall portion is one vertical arm of the U-shape and serves to rotationally mount the pulley. The base portion is the bottom of the U-shape and is generally used to mount the to a structure (for example, a beam in a theatre). The stiffness enhancement portion is the other vertical arm of the U-shape and serves at least to enhance stiffness so that higher capacity pulley assemblies with unitary side plate/base plate members may be achieved.

Abstract: A hoist system with an overspeed detection sub-system for detecting overspeed by comparing an actual drum assembly speed with a target value. For example, the rotation of a motor may be determined by a first rotary encoder and the rotation of a drum may be determined by a second rotary encoder. The output of the first rotary encoder (the basis of a target value) is compared with the output of the second rotary encoder (corresponding to actual motion of the drum). If the difference between the target value and the actual motion is too large, then a problem, such as a broken hoist hardware component may exist, and appropriate remedial action is taken, such as braking the motor and/or the drum.

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 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.

Abstract: A winch system with a force cable that transmits electrical current and/or digital data to the load. For example, the force cable, including a power line and/or a signal line and includes at least: (i) a first portion extending from the load to the drum; and (ii) a second portion that is wound around the drum. If there is a power line in the force cable it is electrically connected to an electrical commutator by a rotating current path. If there is a signal line in the force cable it is connected in data communication to a data signal commutator by a rotating communication path. The commutator also has an input for receiving electrical current and/or digital data, as appropriate. The commutator transmits the electrical current and/or digital data from its input to the rotating current path and/or communication path. The drum defines an axial channel extending from at least one end of the drum along its axial direction, and current path(s) and/or communication path(s) are routed through the channel.

Abstract: A lift system including a visual indicator device (for example, an LED indicator light) in data communication with travel limit switches so that tripping of the travel limit switches (or at least the travel limit switches that are manually set by a human assembler) will cause the visual indictor device to make a visual indication that can be readily observed by the human assembler. The visual indication of the present indication can helpfully replace the conventional method of listening for a click during the step of setting the location of the travel limit switch when the lift system is initially set up by a human assembler. Instead of listening for a click, the assembler can watch for a visual indication by the visual indicator device, such as the lighting of an LED. this can make the assembler's job easier and can facilitate quicker and more reliable setting of the location of travel limit switches in the lift system.

Abstract: A lift system having a modular backbone with two or more backbone sections being attached end to end to form the backbone. Also, a lift system with end to end modular attachment, using universal joints, between motor assembly(ies), shaft section(s), drum assembly(ies) and/or shaft end sections. Also, a lift assembly with a backbone having longitudinally adjustable lift component attachment hardware, such as an elongated slot with lips suitable for engaging a nut tooth.

Abstract: A theatrical lift including a timer and an indicator light. The light indicates a need for maintenance after a predetermined amount of time passes as measured by the timer. Also, a lift, such as a theatrical lift, including an indicator, a reset switch and an indicator housing. The indicator is located on the indicator housing. The reset switch is located inside of the indicator housing. The indicator housing can be opened or partially opened to allow selective access to the reset switch. In this way, the reset switch can be easily reset by a lift maintenance technician as part of performing routine maintenance on the lift, but will not be easily reset by a lift operator as a casual matter.

Abstract: A twisted rope for use in rigging systems that includes a differently colored yarn positioned within at least one strand. As the rope is worn, the differently colored yarn will become exposed, thereby serving as a visual indicator of wear to the rope. A plastic strip printed with identifying information about the rope is placed within the fibers of the rope during manufacture may also be positioned with a strand of the twisted rope. A user can simply unravel one end of the rope and read the information printed on the strip to determine, for example, the composition of the rope, when the rope was manufactured, the load-bearing characteristics of the rope, and who was the rope manufacturer.

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: The invention is a motorized winch which can be retrofitted into existing manually operated systems that use counterbalancing weights. The counterbalancing weight will be fixed at 50% of the maximum capacity of the set. The winch is rated at 50% 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 its rated capacity, without the need to ever adjust the counterbalancing weights.