Field of the Invention

The invention relates to a lighting assembly to illuminate theatre and concert stages and other indoor and outdoor places of entertainment.

Background Art

It has been recognised that stage and like lighting is a specialty and that artists require their own lighting because individual places of entertainment rarely provide adequate or suitable lighting. Lighting assemblies for this purpose comprise at least one, typically two, rows of lamps. Each lamp is of the sealed beam or PAR type. Such PAR (for Parabolic Alu inised Reflector) lamps consist of aluminised reflectors cast of high-temperature glass, which focus the captive incandescent (or preferably a quartz-halogen) bulb capsule output into a beam. The front face of the reflector is sealed by a glass lens, and the surface of that lens may be frosted or facetted to produce different beams. Such lamps are manufactured in at least four reflector diameters from four- and-one-half inches (about 11.4 cm) the PAR-36, to eight inches (about 20.3 cm) the PAR-64 (the number following the hyphen, by convention, designating diameter in eighths of an inch) . PAR- 64 lamps with 1000-watt quartz-halogen bulbs and various beam spreads are used in 90-100% of the fixtures in a typical concert lighting system, as well as by a significant proportion of fixtures in lighting television productions on location. The lamp is received in a housing which is a closed-end cylinder enclosing both the rear of the lamp and electrical socket contacts. A yoke fixed to the housing provides for adjustments in one axis, and the rotation of the yoke about its fixing to a support, in the well-known manner, provides for such adjustments in the other axis. To accommodate light- attenuating metal screens and fibreglass diffusion materials in television applications and coloured glass filters in applications, clips for such filters are present immediately in front of the lamp. Such filters have not been used to any significant degree in modern theatrical or television lighting. Instead, such lamps use so-called "gel" materials (such as the

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Roscolene and Roscolux products of Rosco Laboratories, Port Chester, New York 10573) , which consist of a flexible cellulose acetate, polyester, or MYLAR film with a coloured pigment distributed through it or applied to its surface. Such filters are generally retained between the halves of a folded metal "gel frame" which, in turn, is slipped into folded metal retaining clips provided on the fixture. The housing of such a fixture must incorporate an extension to distance the plane of the filter material from the lamp by approximately one foot (about 30 cm) to prevent radiant energy and heat from damaging the gel filter.

Frame systems or trusses have been designed for ready transport and installation on site of the light assemblies, some trusses being dismantled for transport and reassembled for use and others being preformed. In all cases, the design is inconvenient, either requiring skilled or expensive labour to set up on site, or occupying such volume that only a few can be packed into a standard vehicle container having a length of 40 to 48 feet (about 12.19 to 14.63 metres) and an internal width of 96 inches (about 2.44 metres). One truss comprises a box like structure about 8 to 10 feet in length (about 2.43 to 3.05 metres) , housing two rows of lamps each fixed to a bar arranged to move vertically along guide rails or rods. The lamps are received in the truss for transport and in use the bars are moved vertically to extend the lamps beyond the truss so that they may be panned or tilted to illuminate a stage. The truss typically has an overall width of 30 inches (about 91.4 cm) and three such trusses can be fitted side by side into a standard 96 inch (about 2.43 metres) container, and stacked in three rows, giving a maximum content of 9 trusses, and much wasted space.

Object of the Invention

It is one object of the invention to provide a larp assembly which can be transported at a higher density in .. standard container, without any need for assembly nr. dismantling or drawback in use.

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Summary of the Invention

In one aspect the invention provides a lighting assembly for use in lighting places of entertainment, the assembly comprising at least one row of lamps mounted on a bar support therefor, each lamp comprising a light source located in a housing, a frame located in front of the housing, a light filter being mounted in the frame, the bar being mounted in a truss therefor by which the assembly may be transported characterised in that the frame of the lamps does not exceed 8.5 inch in cross-sectional dimension, so that the width of the truss does not exceed 23 inch (about 58 cm) .

Preferably, the lamps are present on two rows of bars mounted at the same height in the truss. Preferably the truss is less than 23 inch (about 58 cm) high.

In another aspect, the invention provides a transportable container having a width of 96 inches (about 2.43 metres) , the container containing trusses accommodating light assemblies characterised in that the container contains four trusses, arranged in side-by-side relation.

In another aspect, the invention provides a transportable container having a width of 96 inches (about 2.43 metres) , the container containing light assemblies mounted on travelling racks therefor characterised in that the racks contain lamps on bars and according to Claim 1, five such bars being mounted on a rack 46 inches (about 1.17 metres) in width.

Brief Description of the Drawings

In order that the invention may be well understood it will now be described, by way of example, with reference to the accompanying drawings, in which:

Figure 1 is a side elevation of one known lamp and Figure 2 is a vertical section along lines 2-2 on Figure 1;

Figure 3A is a front elevation of a square gel frame, Figure 3B an octagonal frame and Figure 3C a circular frame, each forming part of the lamp of Figure 1;

Figure 4A is a schematic front view of the truss for rows of lamps of Figure 1, and Figure 4B the bottom view, Figure 4C an end view with the lamps in the retracted transport

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condition and Figure 4D the same as Figure 4C with lamps in the extended illuminating condition;

Figure 5 is a side elevation of a lamp fixture of the invention, and Figure 6 is a front elevation thereof, and

Figure 7A is a schematic front view of the truss ^' of the invention, Figure 4 the bottom view thereof, Figure 7C an end view with the lamps in the retracted transport condition and Figure 7D is the same as Figure 7C with the lamps in the extended illuminating condition, and

Figure 8 is an end view of a standard transport container doors in an open condition containing trusses according to the invention arranged side-by-side for transport. Detailed Description of the Preferred Embodiment

For an improved understanding of the invention, known lamps and trusses will first be described with reference to Figures 1 to 4.

As shown in Figures 1, 2 and 3A to 3C a so-called PAR-64 lamp 24 consists of an outer cylindrical housing 26 formed or spun of steel or aluminum. The housing 26 has a rear cap 26A, to which the power cable 36 is fixed and which encloses the rear of a PAR bulb 28 and the insulated socket 40 into which the contacts protruding from the rear of the lamp are plugged. The PAR-64 bulb 28 (Figure 2) is retained within the housing 26 (which at the plane of the rim 30 of lamp 28 is slightly larger than 8 inches (about 20.3 cm) in diameter) , by a flange 32 on one side of the rim 30 and a spring steel retaining ring 34 bearing against the housing, on the other. The PAR lamp 28 produces a beam 56 having an elongated centreline 58 perpendicular to the plane of its rim 30. A U- shaped yoke 42 is attached to housing 26 to permit rotation about a nominally horizontal axis 44, and the yoke 42 is provided with a pass hole 46 (Figure 2) that permits its attachment to a support (110,112, Figure 4A) so as to permit rotation about a nominally vertical axis. Threaded fasteners not shown are used at the various pivot points to permit the rotation of the housing 26, and therefore the light beam, to the desired angle, which may then be clamped in the desired position by tightening the fasteners.

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Clips 60 extend forward from the open end 62 of the housing 26 by a distance of 10 to 12 inches (about 25.4 to 30.5 cm) to receive a gel frame 64 containing a light filter or gel. The known frames 64 have exterior dimensions of 10 inches by 10 inches (about 25.4 cm by 25.4 cm) and an 8 inch (about 20.3 cm) diameter opening 64A. Three stamped metal clips 60 spot-welded or rivetted to housing 26 (or equivalent clips brakeformed in a single assembly) are used to terminate and stiffen the open end of housing 26 and are provided to accept the metal gel frame 64, and spring inserts in those clips or a fourth, hinged, spring-loaded clip top clip 68 is used to retain the frame 64. Whether or not such a top clip 68 is used and/or the corners 64B of such frames are trimmed, to form the octagonal frame 70, as illustrated in Figure 3B, or a round frame 72, as illustrated in Figure 3C, to reduce interference problems encountered in aiming, the overall width and height of the fixture in the plane through such mounting clips remains the same. Viewing the section of Figure 2, it will be seen that the cross-section of the fixture is at its greatest in this plane, which corresponds to the plane through which the fixture is adjusted about a nominally horizontal axis, because the gel frame 64, is considerably larger in cross-sectional area than housing 26.

Two rows of lamps 24 are present on bars 110,112 in the known lamp-supporting trusses 100 shown in Figures 4A to 4D. The two rows are accommodated within the generally rectangular volume defined by the structure of the truss itself, including horizontally disposed top rails 102, horizontally disposed bottom rails 104, vertically disposed end rails 106, and angularly extending side rails 108. Each lar.p 24 in a row is attached to a supporting bar 110 or 112, which extends parallel to the elongated (horizontal) axis of the truss structure and is provided with guide rails or guide bars (not shown) to permit each bar to be raised or lowered between a use (Figure 4D) and a shipping position (Figure 4C) .

It will be apparent that the cross-section of th^ truss is determined by the maximum dimension of the lamps 2... which is established by their gel frames 64. With 20 inc c.

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(50.8 cm) of width consumed by the frames and a 1 inch (2.54 cm) clearance allowed between the two rows of lamps and between each row and the truss structure, the minimum internal dimension between the two sides of the truss required to permit either row of lamps to pass the other in safety is 23 inches (about 58.4 cm). Employing tubing for the rails of the truss structure with a width of 1.5 inches, (about 3.8 cm) increases the width of the truss itself to a minimum of 26 inches (about 66 cm) , far in excess of that required for four-across accommodation in a truck of standard width, i.e. 96 inches (about 2.43 metres) . Most designers and manufacturers have increased the overall width to 30 inches (about 76.2 cm) to produce a better fit in a three-across arrangement.

Figure 5 is a side elevation of a PAR-64 lamp 22 and a truss 20 of the invention. According to the invention, the height of the gel frame 64 is 8.5 inches (about 21.6 cm), and the gel clips 60 and 68 adjusted accordingly, in at least one dimension, preferably in that plane through which the fixture housing is adjusted in azimuth to form smaller clips 160 and 168, respectively. Preferably, both the width and the height dimensions of the frame are reduced, preferably to the same value. Preferably, an octagonal or round frame shape is employed. It has been found that by reducing the size of the gel frame 126 in this way, no drawbacks result and the gel filter is adequately retained.

As can be seen in Figures 7A to 7D, the truss includes PAR-64 lamps 22 in two rows, in the same manner as that described with reference to Figures 4A to 4D, except that the overall width of the truss 20 from front to back, i.e. the length of the rail 104 is reduced to less than 23 inches (about 58.3 cm), which is made possible because the width of the gel frame has been reduced from 10 inches to 8.5 inches (about 25.4 cm to 21.6 cm). This reduces the width of two lamps arranged side by side having such gel frames from 20 inches to 17 inches (about 50.8 cm to 43.2 cm), which, with clearances of approximately 3 inches (about 7.6 cm) and a truss made up of tubular rails of 1.5 inches (about 3.8 cm) outside diameter produces an overall width of 23 inches (about 58.3 cm). This

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enables four such trusses to be arranged on one end in a side- by-side arrangement across a standard trailer 200 having a nominal 96 inch width (about 2.43 metres), as shown in Figure 8.

The improved "drop frame" truss of the invention produces a 33% increase in the number of fixtures which can be accommodated in the same floor area of a trailer as current 30 inch (about 76.2 cm) designs and does so without increasing the height or complicating the setting up operation, or requiring the use of special trailers.

Referring now to Figure 7B, the bottom view of the truss with the lamps 22 in an interior position shows that there is no overlapping and hence no vertical offsetting of the two rows. Because of the relatively reduced size of the gel frame (64), the lamps (24) may be secured to the bars (110,112) in their focussed position in use, and then the bars may be raised to enclose the lamps for transport, without having to change the focal position. It is known to provide a four- across arrangement by using a special non-standard 102 inch wide container, which are not widely available, and using slightly slimmer trusses. However in order to accommodate such a reduction in width the bars having the lamps are vertically staggered so that the standard 10 inch (25.4 cm) gel frames can clear one another. The use of such a vertical stagger means that the low row must be lowered first and raised last, thereby complicating the setting up procedure and ensuring that the staff setting up the lamp system must be supervised. This is in contrast to the truss of the invention, where no such vertical stagger is necessary and two rows of lamps can be raised and lowered in any order. Without such a vertical offset, the height of the truss, i.e. the lengths of frame member 106 can be reduced by an equivalent amount, and the height of a stack of four lengths reduced by approximately one foot (about 30.8 cm) increasing available volume beyond the trusses in the container and improving the stability of the stack. As shown in Figures 7C and 7D a side elevation of th truss shows that the lower chords of both sides of the truss may be at the same plane or one may be higher, in the kncv

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manner. The length and height of the truss may be varied, an means (not shown) used to link truss lengths together to for longer free-spanning structures. The means may be of an known type including bolts, pinned clevis fittings, o structural cam-latches.

Casters (not shown) may be provided on the bottom o one end face of the truss for portability or a separate doll may be used.

The bars used to support the lamps, may be positivel locked in the shipping and/or one or more use positions by an known means, and may distribute electrical power to the lamps in the known manner. Such bars may also be made readil removable from the truss structure in the known manner.

The invention is not limited to the embodiment shown. Bars may be separated from a truss frame for transport o travelling racks therefor, known as "meat racks". Because o the size of the known gel filters, only nine such bars can b transported in a standard container whereas ten bars containin lamps of the invention can be transported, five bars each bein mounted on a rack 46 inches (about 1.17 metres) in width. Th invention is also not limited to a truss having two rows of bars, because three rows or a single centre mounted bar may b present. The lamps may be of different types, such as 2k an 5k French, softlights, Varilights, beam projectors and cyc- lights. Because of the compact size, different options o packing a trailer are available. For example, when housing 26 is shortened in height to a dimension, which includes the yok 42, of less than 15.5 inches (about 39.4 cm), five rows of lamps can be transported sideways in a typical 96 inch (abou 2.64 metres) wide trailer.

By fabricating a framework or module of 18 inches (about 45.7 cm) or less, five modules containing PAR-64 lamps, can be transported across the width of a trailer. In a framework of 48 inches (about 1.32 metres) or less, with th opposing dimension being 100 inches (about 2.7 metres) or less, the framework may contain twenty four PAR-64 lamps, in a configuration of four rows, each having six lamps per row. When utilizing PAR-56 fixtures, four rows of eight lamps may b

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accommodated. The frameworks or modules are then transported either on the short or long end, with or without casters.

It will be appreciated that the invention of this application involves a relatively simple structural change over known structures of lamp. It is surprising that such a structural change has not been considered before, given the realisation that the designs currently in use have drawbacks. While the industry has been aware of the drawbacks, there has been a prejudice among experts skilled in the art that the drawbacks would be overcome by complex changes in the structure, not simple ones, see e.g. in Lighting Dimensions, March 1983, where Michael Callahan surveys the tour system designs for the 1980's and concludes:

"A lack of progress is leading to the suspicion that the tour system may have it a sufficiency barrier, that we. have simply run out of cheap off the shelf solutions and that any further substantial progress will require equipment that costs so much to develop, build and operate that for most of the market the costs will outweigh the benefits" (see page 66) .

Without further elaboration the foregoing will so fully illustrate my invention that others may, by applying future knowledge, adopt the same for use under various conditions of service.

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