METHOD AND APPARATUS FOR STAGE RIGGING

Abstract

An apparatus for use in rigging stages includes a portable bar sized to extend across standard widths of a tower or a cross beam with a portion extending beyond the side of the tower or beam. A lifting mechanism, such as a block-and-tackle, is attached to the portion to allow a rigger to raise or lower heavy objects. In a method of use, a rigger carries the lifting bar to a desired location on a tower or beam and secures at least one end of the portable bar to one or more cross bars. Then the rigger can raise or lower heavy objects by attaching a flexible line from the lifting mechanism to the object and manipulating the lifting mechanism to assist in moving the heavy object to a desired location.

Claims

1. Apparatus for use by a rigger to raise or lower fixtures used on a stage comprising a portable lifting bar, a bracket at one end of said portable lifting bar configured to attach to a cross bar of a stage tower or beam, and a self-locking pulley at the opposite end of the portable lifting bar.

2. Apparatus according to claim 1 wherein said pulley is part of a block-and-tackle.

3. Apparatus according to claim 1 wherein said lifting bar comprises an aluminum bar with a hollow core.

4. Apparatus according to claim 3 wherein said hollow core encases a wood bar having an outside surface that engages an outer surface of said hollow core and provides additional strength to said lifting bar.

5. Apparatus according to claim 1 further comprising a rod on each side of said lifting bar to provide additional strength to said bar.

6. A method for rigging a stage comprising the steps of attaching an apparatus according to claim 1 to first and second opposed cross bars of a stage tower, attaching a block-and-tackle of said apparatus to a load to be carried, and operating said block-and-tackle to raise or lower said load.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] FIG. 1 is a top view of an apparatus in accordance with the invention.

[0012] FIG. 2 is a perspective of a stage tower showing the invention in use.

[0013] FIG. 3 is a cross section of an embodiment of a lifting bar in accordance with the invention.

[0014] FIG. 4 is a perspective of another embodiment of a lifting bar in accordance with the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0015] With reference to FIGS. 1 and 2, the invention includes a portable lifting bar 2, which can be an elongate bar as shown that is rectangular in cross section. It can be of many different materials such as aluminum such that it is light but strong enough to support anticipated loads, e.g., 500 pounds. A second part of the invention is a block-and-tackle 4 that can be attached to one end of the portable lifting bar as shown.

[0016] FIG. 2 illustrates a portion of a stage with a tower 6 that is known in the art and used for supporting such items as stage lighting and other staging fixtures, such as movable scenery and the like. The tower 6 includes upright elements 8, cross bars 10, and braces 12. An apparatus in accordance with the invention is shown in FIG. 2 attached to the tower in an operational condition. The portable lifting bar 2 extends across two adjacent bars 10 located on opposite sides of the tower, preferably at the same height above the floor that supports the tower 6. One end 14 of the portable lifting bar includes a bracket 16 that can easily and quickly be attached to a bar 10 to secure that end of the portable lifting bar to the tower. The portable lifting bar is long enough to extend from one bar 10 across the tower to a bar 10 on the opposite side of the tower and then beyond the bar on the opposite side whereby the opposite end of the portable lifting bar will position the block-and-tackle far enough from the side of the tower to allow a lighting fixture or other object to be mounted to the tower or beam or other staging structure by a rigger. For example lighting towers (trusses) are often either twelve or twenty inches in width, and the length of the portable lifting bar can accommodate those widths.

[0017] For example, the portable lifting bar illustrated in FIG. 1 provides three brackets 16, wherein a first of the brackets is positioned at one end of the portable lifting bar, a second bracket is positioned to accommodate a twelve-inch-wide tower, and a third bracket is positioned to accommodate a twenty-inch-wide tower. Thus, the bracket at the first end can be attached to a cross bar 10 and one of the other two brackets attached to the cross bar on the opposite side of either a twelve-inch tower or a twenty inch tower, depending on the circumstance.

[0018] FIG. 2 illustrates an arrangement for lifting a fixture 22. A block-and-tackle 4 is attached to an end 18 of the portable lifting bar at a connector, such as eye bolt 20. The fixture is attached to a movable pulley 24 of the block-and-tackle 4 by a rope 28. The rigger can easily raise the fixture to the desired height by pulling on the rope 26.

[0019] The block-and-tackle preferably is of the type that includes a locking element (not shown) that holds the load until raised further by pulling again on the rope 26 or lowering the load by operating the rope 26 to release the locking element.

[0020] The bar can be of various constructions, depending on the expected loads to be lifted. The bar can be made of wood and of various cross-sectional shapes. A rectangular cross-section is preferred for ease of use an attachment to the elements of a tower. As noted above, the bar can also be made of aluminum with a hollow core to render it lighter. Other metals could be used as well. Also, the hollow core can be filled with a wooden element configured to fit tightly in the interior of the aluminum bar to add additional strength. Various types of wood can be used, such as oak. Additional strengthening components can be added depending on the loads to be lifted and keeping in mind the objective that it be lightweight to facilitate transport and maneuvering by the rigger.

[0021] FIG. 3 is a cross section of a lifting bar 2 and illustrates the embodiment of the invention where the portable lifting bar 2 comprises a metal bar, e. g., of aluminum, that has a longitudinal hollow core formed by an inner surface 30. The hollow core is filled with a second bar 32, preferably made of wood, and extending the length of the aluminum component, to add rigidity to the aluminum. FIG. 4 is a perspective of a lifting bar with additional rods 34 on opposite sides of the bar 2 and fitted in grooves 36. The rods may be secured to the bar in any of various ways. They can, for example, be welded or brazed to the bar or they can be threaded at one or both ends and secured by a nut 38 at one or both ends to clamp the rods to the bar. The bars should have high tensile strength and may be made of metals, such as steel, or other appropriate materials including composites.

[0022] In operation, a rigger can easily carry the portable lifting bar and the block-and-tackle to a location on a tower or beam near the location of a fixture that is to be detached or the location where a fixture is to be installed. For example, it is common for a rigger to carry a tool bag, and the portable lifting bar and block-and-tackle can easily be placed in the tool bag or attached to it. The rigger then places the portable lifting bar across two of the cross bars 10 and secures at least the one end opposite the block-and-tackle to a cross bar on the side of the tower opposite the load to be raised. Then the rigger operates the rope 26 to raise a load that is already attached to the block-and-tackle or attaches the block-and-tackle to the load to be lifted and then operates the rope 26 to raise the load.

[0023] Modifications will be apparent to those of skill in the art. For example, the lifting bar may be made of composite materials, such a carbon fiber composites, metal alloys, etc. As well, a winch may be substituted for the block-and-tackle. Because weight is of paramount concern, the winch would be manually operated from both the stage or from an elevated position. Other modifications will be apparent to those of skill in the art.