Abstract:
A modular lighting system is formed of tubular fluorescent lamps mounted within adjustable fixtures. The fixtures are composed of rigid and flexible elements and can conform to the shape of almost any size or shape of lamp. The lamps may be of any variety of pre-determined shape, curvature or length, to meet the desired lighting requirement. Each fixture may include a lampholder, lamp retention device, mounting surface, ballast, enclosures, and specially-molded flexible special power cable which flexibly connects the rigid elements or assemblies of each fixture. Electrical connections are made between each adjacent fixture with integral male and female flexible power cords. Thus, a custom-made fluorescent lighting system is created using standardized flexibly adjustable fixtures and any variety of lamp shapes or lengths. The system may be installed and electrically connected without any disassembly or tradition field-assembled and installed wiring, minimizing effort for installation or removal.

Description:
FIELD OF THE INVENTION 
   The present invention relates to a modular, field-adjustable, linear lighting system in which one fixture universally accepts almost any size or shape of prefabricated tubular lamp. 
   BACKGROUND OF THE INVENTION 
   Traditionally, tubular fluorescent lighting products which are utilized to provide a continuous uninterrupted line of light for both curved and straight lighting applications can be separated into three categories: 
   1). Fixtures and systems which use standardized straight tubular lamps in novel ways (either by overlapping, staggering or angling) to both navigate curved and straight architectural details, and overcome the problems created by the non-illuminated lamp end(s). 
   2). Fixtures and systems which utilize straight tubular lamps (e.g., butt-ended cold cathode fluorescent lamps) which, through their unique construction, do not exhibit the typical non-illuminated lamp end(s), thus providing continuous even illumination from one end of the lamp body to the other, allowing end-to-end installation. These straight lengths are configured in various ways, e.g., angled or overlapped to conform to curved and/or straight architectural requirements. 
   3). Fixtures and systems which utilize the uniquely constructed lamps described in the paragraph above in which the lamps may also be made as custom or standardized straight, bent or custom-curved elements that can conform to almost any architectural or design requirement. 
   Examples of systems which utilize standardized straight tubular lamps and fixtures described in category #1 would include a simple staggered fluorescent fixture, such as the one currently manufactured by Bartco. The non-illuminated ends of the lamp are compensated by overlapping the tubular lamp body. This type of system could be used for straight or very gently curved applications, the length of the standardized lamp determining the minimum radius on which they can be installed. Systems which utilize a staggered lamp configuration suffer from overly bright areas of illumination where the lamps overlap, and can produce a pattern of alternating brightness when the fixtures are used in an indirect application. Additionally, because the lamps are configured side-by-side, and not in a true linear array, even the untrained eye can see that the surfaces closest to each lamp are more brightly illuminated than those even slightly farther away. That is, where tubular lamps are staggered side by side, the cove will exhibit uneven light distribution. The lamps closest to the back of the cove will create a lower-brightness light pattern at the front of the cove, and lamps closest to the front of the cove will produce a lower-brightness light pattern at the back of the cove. 
   Some manufacturers utilize smaller biax or compact-fluorescent lamps in an overlapping or non-overlapping placed array. In the case of this type of lamp, only one end of the lamp is not illuminated. This type of lamp is essentially a “U” shaped tubular fluorescent that has an exceedingly small area in which the lamp returns on itself, giving it the appearance of twin lamps, side by side. To conceal the non-illuminated portion of the lamp that accommodates the lamp base, these lamps can be mounted in an overlapping fashion in which the illuminated end of one lamp conceals the non-illuminated end of the adjacent lamp. These lamps can be installed on fixtures that are either straight, semi-flexible, or segmented with a swiveling feature, allowing the fixture itself to be field-curved to the desired shape. Examples of this type of fixture are manufactured by Belfer, Inc. Each lamp is attached either at a tangent to a semi-flexible curvable element or to a curvable, swiveling, segmented element. The curvable elements are designed to accommodate a plurality of straight, small lamps and usually contain the power supplies which operate the lamps. The disadvantages of the above-referenced system are that the non-overlapping lamp configuration exhibits dark spots and shadowing between the lamps, and the overlapping system is not as maximally efficient due to the relatively high lamp quantities and corresponding high wattage densities required by the overlapping feature. 
   Examples of systems that utilize straight tubular lamps and fixtures described in category #2 would include a cold cathode fluorescent lighting system shown in U.S. Pat. No. 6,454,431, incorporated herein by reference. There, a lighting system having self-contained aluminum-extrusion fixtures accept a variety of standardized lamp lengths. The standardization of the fixture and lamp sizes minimizes manufacturing and project design expenses. The lamps are uniquely constructed to provide uniform illumination from one end of the lamp to the other. The lamp base and cathode that would normally create a non-illuminated space at each end of the lamp has been moved behind and underneath the lamp, allowing continuous illumination at each end of the lamp body. The fixtures, and correspondingly, the lamps, may be arranged end-to-end, producing a continuous shadow and gap-free line of light. To transition slight curvatures, fixtures can be installed at angles to one another. Depending upon the radius required and the most minimal lamp length, a limited variety of very large gentle radii can be accommodated. Smaller radii and complex curvilinear shapes cannot be accommodated. This is an inherent disadvantage of the system. It is not offered as a curved or bent fixture that could accommodate curved or bent lamps needed for more complex and curved architectural requirements. 
   Another example of a fixture of this type is the Seamlessline fixture, manufactured by Nippo Inc. This fixture utilizes a special standardized fluorescent lamp, which is manufactured to provide complete illumination of the tubular lamp body. Again, lamps can be installed to transition gradual curves depending upon the radius required and the most minimal lamp length. The lamp utilized in this type of fixture is of the “hot cathode” design. The lamp life is typically 12,000 hours, far less than the 50,000 hour cold cathode fluorescent lamp. This system is offered in straight lengths only. 
   Examples of systems that utilize tubular lamps and fixtures described in category #3 would include a cold cathode fluorescent lighting system manufactured by Cathode Lighting Systems. This is a component-based system which is comprised of custom-made lamps and lamp components that can either be field assembled or partially factory assembled utilizing standard electrical conduits, conduit connectors and wiring. The lamps can be fabricated to nearly any shape as desired, either straight, curved or bent. Each of the components is shipped separately to the installation site where a contractor installs the conduit and wiring between the lampholder and ballasts. These systems are almost always field-assembled. 
   A disadvantage of the system is that it is costly to install, and must be field-assembled from a variety of components (some provided by the lighting manufacturer, and some provided by the installing contractor). The lampholders retain and electrically connect the ends of adjacent lamps to the lamp ballast(s). This assures the spacing between lamp ends is always maintained at the proper dimension. On the other hand, because the lampholders retain the ends of adjacent lamps, there is little room for adjustment of the system if adjustment is required. The system is essentially built to a fixed dimension, and each lamp dimension and placement is dependent upon the adjacent segment. Any readjustment of lampholder positioning or spacing of an individual segment would either break the lamp(s), or require a redesign of the lamp(s) or system. Because field conditions vary, the ability to reposition the system and manipulate the spacing of the lamps ends would be advantageous. 
   Another cold cathode lighting system has been suggested where a continuous channel which contains the power supply and wiring for the lamp is custom-built to the exact shape of the lamp. An example of this system is manufactured by Neotek, Inc. The channel is assembled using a combination of extruded shapes and/or flat metal elements that can be factory-fabricated to form straight, curved or bent elements, to follow the shape of the custom-made lamp. These fixtures do not contain lampholders, which in almost all tubular light fixtures, connect the lamp (via a lamp base) to the power supply. Lamp base(s) and lampholder(s) type fixtures allow easy insertion and removal of a lamp, without any disassembly of the fixture. Rather, in the Neotek fixture, lamps are glued to the top portion of the snap-on channel and are connected to the power supply via a flexible conductor. The disadvantages of this product include the following: 
   A). A uniquely shaped or dimensioned custom channel must be factory-built for each unique lamp shape, requiring substantial labor, and if the fixture is dimensionally incorrect, it cannot be field-adjusted, it must be remade, along with the lamp. 
   B). Because the lamp is glued to the removable top portion of the channel and does not utilize traditional lamp bases and lampholders, if a lamp needs replacement, an entire new glued-together top channel and lamp assembly must be fabricated. 
   C). There are some limitations as to how small a radius or acute angle this type of (or any type of metallic channel-based) fixture can be manufactured to duplicate. These limitations are based on the physical properties of the material, the overall size of the channel and the limitations of the manufacturing techniques. 
   D). If field conditions dictate that a few fixtures in a predetermined array length require more separation between fixtures, these open-ended fixtures must be enclosed at each end, and like almost all linear fixtures (e.g. the fixture described in the &#39;431 patent, which are always enclosed at each end, and allow concealed wiring from one fixture to the next, via standard electrical knockouts and standardized electrical fittings) will require external rerouting of the internal wiring, via electrical conduit, from one fixture to the next. 
   There is a desire for a fixture that can accommodate virtually any size or shape tubular lamp, essentially a “one size fits all” fixture. Also desired is an uncomplicated method of installing the desired fixture, such that a contractor can install the fixtures, install the lamps within the fixtures, and electrically connect the fixtures to each other, and electrical power, without any disassembly of the fixture whatsoever. Also desired is a fixture that can be field-adjusted or spaced at a variety of distances or orientations from each adjacent fixture without the requirement of building additional conduits or raceways to electrically connect one fixture to the next. 
   SUMMARY OF THE INVENTION 
   The present invention overcomes the problems of the prior art by providing a modular and flexible tubular lighting fixture system. The system combines pre-fabricated fixture elements connected by flexible elements to form a fluorescent light fixture which can be custom fit for easy installation. The system may advantageously include a plurality of lamps having any of a variety of lamp shapes, curves, colors, and/or sizes, which can be custom made to accommodate a particular location. The lighting system may be extremely easy to install when compared with other similar products. 
   In a preferred embodiment of the invention, a modular system for generating light has a plurality of fixtures. Each fixture has a plurality of casings electrically connected by a flexible special power cable, at least one tubular fluorescent lamp supported by the casings, and a ballast or ballasts for providing power to the lamp(s). Preferably, the fixtures are electrically connected together in parallel, using flexible power cord segments received at each end of the fixtures. In accordance with one aspect of the invention, the fixture can be mounted to a surface while completely assembled, electrically connected to adjacent fixtures and/or the primary circuit, with or without the lamp installed, and requires no disassembly during this process. In accordance with another aspect of the invention, each fixture functions as an independent element, and the elements combine to provide a continuous line of light. In a preferred embodiment, the fixtures do not need to be mechanically fastened to one another, or connected with additional electrical conduits to provide a safe interior wire passageway from one fixture to the next. Rather, an electrical connection is made externally from fixture to fixture via a series of flexible, modular, multi-pole electrical connectors. 
   In accordance with another aspect of the invention, a unique multi-conductor special power cable is used to connect the casings that enclose the lampholders and the lamp ballast(s). In a preferred embodiment of the invention, the special power cable is a molded polymeric cable that contains all of the conductors necessary to carry line-voltage electricity (and or the low-voltage DMX dimming signal) to the lamp ballast(s), and a special high-voltage conductor (or conductors) which carry the high-voltage electricity from the ballast(s) to the lamp(s). The special power cable is very flexible, it can be curved to any suitable radius, or bent to any suitable angle, or may be coiled to make the overall length of the fixture shorter. Unlike traditional flexible metallic conduit, the preferred special power cable will not unravel when subjected to forcefull extension and, unlike flexible non-metallic conduit, offers a smaller, more discreet footprint, and the special power cable will not “spring back” when curved into a shape, nor will it hold the memory of the coiled shape in which it is bulk packaged. 
   In accordance with an exemplary method for installing the lighting system, a custom lamp is pre-manufactured to a desired length or shape. The uncomplicated installation process may involve arranging a series of fixtures to match the approximate lamp shape or length, snapping the lamp into a lampholder on the fixture, positioning a lamp retaining clip around the lamp body, fastening the fixture to the mounting surface, and coupling the flexible electrical connectors to the adjoining fixture or power feed. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other objects and advantages of the invention will become apparent from the following detailed description and drawings which illustrate preferred embodiments of the invention, in which: 
       FIG. 1A  is a perspective view showing one fixture constructed in accordance with a first exemplary embodiment of the invention with partial views of an adjacent fixture on each end of the fixture prior to mounting and electrical connection; 
       FIG. 1B  is a perspective view of the complete fixture and partial adjacent fixtures shown in  FIG. 1A , showing the leftmost segment prior to electrical connection, and the rightmost segment after electrical connection; 
       FIG. 2A  is a perspective view of a three-fixture array composing a lighting system, shown just prior to mounting and electrical connection, constructed in accordance with the first exemplary embodiment of the invention; 
       FIG. 2B  is a perspective view of the three-fixture array of  FIG. 2A  shown after electrical connection; 
       FIG. 3  is a perspective view of a two-fixture, circular lighting system constructed in accordance with a second exemplary embodiment of the invention; 
       FIG. 4A  is a perspective view of a two adjoining fixture ends (showing ends prior to mounting and electrical connection) for use in a lighting system in accordance with the invention; 
       FIG. 4B  is a perspective view of the two adjoining fixture ends shown in  FIG. 4A , shown after electrical connection; 
       FIG. 5  is a back-side view of a fixture end for use in a lighting system in accordance with the invention; 
       FIG. 6  is a cross-sectional view of a wire lamp clip utilized in accordance with the invention; 
       FIG. 7A  depicts the wire retaining clip (laying flat in its packaging position) shown in  FIG. 6 ; 
       FIG. 7B  depicts the swiveling action of the wire retaining clip shown in  FIG. 6 ; 
       FIG. 7C  depicts a first in a sequence of exemplary steps involved to utilize the wire retaining clip shown in  FIG. 6 ; 
       FIG. 7D  depicts a second exemplary step for utilizing the wire retaining clip shown in  FIG. 6 ; 
       FIG. 8  is a side-view of an individual fixture and a partial view of an adjoining fixture in accordance with the invention; 
       FIG. 9  is a simplified electrical and schematic diagram depicting wiring components (including enclosures, special power cables, modular connector cords, lampholders and ballast) assembled in accordance with an exemplary embodiment of invention; 
       FIG. 10  is a cross-sectional view of a special power cable constructed in accordance with the invention; 
       FIG. 11  is a cross-sectional view of the lamp base and lampholder assembled in accordance with an exemplary embodiment of the invention; 
       FIG. 12A  is a side and partially-transparent view of the lamp base and lampholder just prior to assembly in accordance with an exemplary embodiment of the invention; 
       FIG. 12B  is a cross-sectional and partially-transparent view of the lamp base and lampholder just prior to assembly in accordance with an exemplary embodiment of the invention; 
       FIGS. 13A-F  are diagrams showing how the flexible special power cable of  FIG. 10  can be manipulated or shaped to manipulate the fixtures into almost any shape or length in accordance with the invention; 
       FIGS. 14A-C  are schematic diagrams showing a 3-lamp assembly (three-color, e.g. red, green and blue, or any other variation of colors or whites, each color being separately controllable) constructed in accordance with the invention; 
       FIGS. 15A-C  are schematic diagrams showing a 4-lamp assembly (four-color, e.g. Cyan, Magenta, Yellow and white or any other variation of colors or whites, each color being separately controllable) constructed in accordance with the invention; 
       FIG. 16  is a flow chart depicting an exemplary method of installing a lighting system in accordance with the invention. 
   

   DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
   Referring now to the drawings, wherein like reference numerals indicate like elements, there is shown in  FIGS. 1A-1B  and  2 A- 2 B a lighting system  100 , or portions thereof, in accordance with a first exemplary embodiment of the present invention. The lighting system  100  includes a plurality of light fixtures, (composed of flexible special power cable segments which connect individual enclosures)  102  holding in-place sections of a tubular lamp (e.g. cold cathode fluorescent lamp)  101 . The system  100  is intended for (but not limited to) use in indirect lighting environments, such as within a cove (not shown in  FIGS. 1  or  2 ) to illuminate a ceiling. 
     FIG. 1A  depicts one fixture  102  with portions of the adjacent fixtures  102 , shown just prior to electrical connection and mounting of the fixtures  102 .  FIG. 1B  shows the fixtures  102  of  FIG. 1B  as they would be mounted. The arrows at the left hand side of this Figure depict the electrical connection that is made, as shown by the fixture ends on the right hand side of the Figure. Similarly,  FIG. 2A  depicts a system  100  that includes three fixtures  102  and lamps  101  just prior to mounting and connection, while  FIG. 2B  shows the system  100  with the fixtures  102  having been connected. 
   Each lamp (e.g. cold cathode fluorescent lamp)  101  has a tubular light transmitting body with opaque or light-emitting ends  112 . In the system  100  illustrated in  FIGS. 1A-1B  and  2 A- 2 B, the lamps  101  are curved in an S-shape. In accordance with the invention, the lamps  101  may be of any suitable size and shape. Thus, each lamp  101  may be short or long, straight, curved, or bent depending upon the environment in which they will be installed and the desired illumination effect. The lamps  101  may be a stocked design, or may be custom built to meet the requirements of a particular design. Regardless of the size and shape of the lamps  101 , the fixtures  102  may be designed to receive and operate with any lamp  101  as described herein. Thus, the fixtures  102  may be mass-produced and combined with tubular lamps (e.g. cold cathode fluorescent lamps)  101  of any suitable design to provide an off-the-shelf assembly that is easy to install, without the need for extensive labor involved in building a fixture to the exact shape of the lamp, or building a system in-place at the installation site to accommodate the unique lamp shapes. 
   As shown in  FIG. 3 , a perspective view of a second exemplary lighting system  200  (showing two fixtures  102 ), cold cathode lamps  201  may be curved to form a closed loop system  200  having a radius R. According to one aspect of the invention, the loop system  200  may have a smaller radius R than could be constructed with a conventional lighting system, while maintaining the benefits of easy installation. Another benefit that may be realized by the invention is that while the curved lamps  201  of the closed loop system  200  differ from the S-shaped lamps  101  used in the embodiment above, each of the other elements of the systems  100 ,  200  are identical. Thus, the fixtures  102  and special power cable  103  of the invention can be interchanged between the two custom-built lighting systems  100 ,  200 . 
   Lamps  101 ,  201 , etc. may be of any suitable customized shape and size in accordance with the invention, and therefore, the invention is not limited to the specific arrangements  100 ,  200  shown in the drawings. For purposes of simplification of discussion, most of the description herein will refer to the first exemplary lighting system  100  and its components, but it should be understood that the components may be interchangeable to form other modular lighting systems as desired. Even within a single system  100 , the lamps  101  may comprise many shapes and sizes. 
   Exemplary systems may have either an individual fixture as shown in  FIG. 1A  or may be multiple fixtures, as shown in  FIG. 2B , located back-to-back, and electrically connected to the adjacent fixture  102  to function as a continuous lighting array. 
   The modular fixtures  102 , when mounted back-to-back as shown in  FIGS. 1B and 2B , provide a system  100  that can maintain a continuous line of light achieving many benefits over conventional fluorescent lighting fixtures. For example, unlike many conventional lighting systems, the fixtures  102  do not need to be mechanically fastened to one another or affixed with additional conduits to provide a wireway or wire passageway from one fixture to the next. Most conventional fixtures must be disassembled and hard wired to the next fixture using standard electrical wiring and wire connectors (e.g. twist-on wire connectors). Some fixture manufacturers utilize modular connectors, which allow the electrical connection of one fixture to the next without the labor of cutting, stripping, and twisting the wires together and applying a twist-on wire connector to each connection. These fixtures are referred to colloquially as “plug and play” types. The typical modular connector (because of its design, UL listing, and the requirements of the National Electric Code) must reside, protected within the fixture(s) or raceway(s) where the hazard of the connector accidentally becoming unplugged or the hazard of unenclosed conductors is not an issue. Correspondingly, connection of the modular connectors requires at least a partial fixture disassembly during installation. In that case, the modular connections are fed through holes or passageways in each end or side of the fixture, and coupled before fixtures are reassembled and the lamps can be installed. 
   In accordance with the present invention, electrical connection between two adjacent fixtures  102  is made using the modular connectors  107 ,  207  ( FIGS. 4A and 4B ) located at the end of a cord segment  113  extending from each casing at the end of a fixture. Because of a high strength locking design and a cable jacket design and rating, the connection between fixture ends can reside on the outside of each fixture-end enclosure, providing a flexible electrical connection from one fixture  102  to the next, or to line voltage  106 , at one end of the system  100 . Accordingly, disassembly of the fixtures  102  during installation is not required to make these connections. As shown in the Figures, one of the modular connectors  107  is “female”-type connector  107  which can be mated to a “male” type connector  207  at an end of the adjacent fixture  102 . This type of connection locks together and is quite flexible, allowing for quick and simple connection of fixtures and to the line voltage during installation and/or disassembly. 
   At one end of the lighting system  100 , the modular connector  107  does not have a mate, as what would be the mating connector  207  is connected to a power source  106  ( FIG. 2A ). Accordingly, a cap  108  is used to prevent electrical problems of having an exposed unmated female modular connector  107 . The cap  108  can be made of any approved resistant material, and preferably, it screws and locks into connection with the unmated end  107  or  207  (if applicable) to completely cover its end. The power source  106  can supply either  120  or  277  volts of electricity, which is converted by the ballast to the higher voltages required by the lamp(s)  101 . 
   As shown in  FIG. 8 , each fixture  102  is preferably composed of three casings  102   a ,  102   b ,  102   c , although it should be understood that only two casings may also be utilized in accordance with the invention. Where three casings  102   a ,  102   b ,  102   c  are utilized, the middle casing may comprise a ballast  120 . Alternatively, the ballast  102  could also be enclosed in either of the end enclosures  102   a  or  102   c , along with the one of the lampholders  104  ( FIG. 9 ) thereby eliminating the middle enclosure  102   b . Each casing  102   a ,  102   b ,  102   c  may be made from lightweight aluminum extrusions which snap together. The casings  102   a ,  102   b ,  102   c  include a side plate  118 , and a top cover  116  having openings  115  for the lampholders  104  ( FIG. 9 ) within the fixture cover  116 . 
   In addition, as shown in  FIGS. 4B and 5 , each fixture casing  102   a  may have several reflectors  303  extending from the top cover  116 . In a preferred embodiment, at least the casings  102   a ,  102   c  that form the fixture ends have one reflector  303  extending upward from each side of the opening  115  on the casing cover  116 . Thus, the reflectors  303  are on either side of the lamp  101 , specifically near the end  112  of the lamp tubing. Even though the gap between fully-illuminated adjacent lamp ends is minimal (0.125″-0.250″), there is still the possibility of a slight shadow appearing on an adjacent surface, especially if the surface is very close to the lamps. The reflectors  303  reflect and distribute the light in a random pattern away from the lamp ends  112 . Used in this position, the reflectors  303  thereby serve to soften any potential shadowing effect caused by this minimal gap between two adjacent lamps  101 . 
   Next, with reference to  FIG. 5 , a back side view of one of the exemplary fixture casings  102   a ,  102   c  at an end of the fixture  102  is shown. Each of the casings  102   a ,  102   c  that is coupled with another fixture casing  102   a ,  102   c  to form a fixture array has two cable/cord input/output openings  301 ,  302  on an end plate  118  of the fixture casing  102   a ,  102   c . The first input/output  301  accepts the first cord  113  ( FIGS. 4A and 4B ) having a modular connection  107  at one end. The second input/output  302 , located under the first input/output  301  on the end plate  118  accepts the special power cable  103  ( FIGS. 4A and 4B ). Each input/output  301 ,  302  should be designed to accept and hold in-place an associated cable/cord  113 ,  103  utilizing a suitable strain-relief device. The cord  103 , and special power cable  113  can be pre-assembled to the casings, such as casing  102   a ,  402   e . Also shown in the side view of  FIG. 5  are the reflectors  303  and a wire clip  105 , discussed below, used to hold the lamp tube  101  in place. 
   Preferably each casing enclosure  102   a ,  102   b ,  102   c  has a wire clip  105  ( FIG. 6 ) extending outward and upward from a plate  305  attached to the fixture cover  116 . The plate  305  may be mechanically attached to a top surface of the cover  116 . The plate  305  may be fixed. The clip  105 , which is captured between a machined or formed groove on the shorter width of the underside of the plate  305  and the top surface cover  116 , may be allowed to slide side-to-side and rotated into a horizontal position so that it lays flat against the top surface cover  116 . This side-to-side adjustability and flat-to-vertical hinging feature provide at least two benefits. Firstly, the clip  105  can be orientated into a flat horizontal position for packaging of the fixture, and swiveled up and around the lamp body  101  during the appropriate stage of installation. Secondly, since the wire clip  105  can be adjusted left or right when receiving a lamp  101 , the wire clip  105  can receive a lamp  101  even if the curvature or shape of the lamp creates a slight misalignment, and prevents insertion into clip  105  in its centered position. 
   As shown in  FIG. 6 , the wire clip  105  is pre-assembled in a shape in which the maximum distance W is substantially the same as the diameter of the lamp  101  which will be held therein. At a tip  304  of the wire clip  105 , the spacing should be less, such that some force needs to be applied to squeeze the lamp  101  into the wider area  306  of the clip. Once a lamp  101  is within this wider area  306  of the clip  105 , it should also take force to remove the lamp  101  from the clip. Thus, the clip  105 , in addition to the lampholders  104  ( FIG. 8 ) serves to hold the lamp  101  properly in place at each fixture casing  102   a ,  102   b ,  102   c.    
     FIGS. 7A-7D  depict the wire clip  105  during various stages of installation for a system  100 . As shown in FIG. A, the wire clip  105  is laying flat (for packaging). As shown in  FIG. 7B , the wire clip  105  moves between a flat position against the fixture cover  116  and a vertical position. As shown in  FIGS. 7C and 7D , and as discussed above, a small amount of force is used to lift the clip  105  from the flat to the vertical position to squeeze the lamp  101  through the wire clip tips  304  into a wider section of the clip  105  where the lamp  101  is firmly held in place with the clip  105  in a vertical position. The wire clip  105  can also swivel side-to-side while in the vertical position if required. 
   With reference to  FIGS. 8 ,  9 ,  11 , and  12 A-B, at the end of each lamp tube  112 , the lamp  101  terminates in a flat surface  112 . The underside of the lamp end includes a second smaller tubular element  101 A fused at 90 degrees to the lamp  101 . Fused to tubular element  101 A is a third tube in parallel relationship to lamp  101 , which contains the lamp electrode  101 B. The lamp base  101 C includes a hollow portion in which to accept the end of the electrode  101 B, and a concave portion that cradles and is adhered to the underside of lamp  101 , as described in U.S. Pat. No. 6,454,431 (assigned to Cathode Lighting Systems, Inc.) and incorporated herein by reference. The bottom surface of lamp base  101 C is fitted with a tubular brass ferrule  101 D, which is electrically connected to the lamp electrode  101 B. A lampholder  101 E is mounted to the bottom of the enclosure  102   a , and contains a hollow portion with spring bronze retaining clips, which retain and electrically connect the ferrule  101 D. The lampholders  101 E are wired directly through the special power cable  103 , discussed in detail below, to each of the ballast secondary leads as shown in  FIG. 9 . 
   As required by the National Electric Code, all luminaires must have suitable mounting provisions. Most channel-type fixtures of the type described above are fastened to a surface by removing the cover of the fixture and screwing or bolting through the bottom inner surface of the fixture to the mounting surface, and then replacing the enclosure cover and the lamp. Because non-disassembly of the fixture during installation is very desirable and minimizes labor, the casings  102   a ,  102   b ,  102   c  in the fixture may contain a mounting surface  109  for mounting the fixture  102  to a surface. In accordance with a preferred embodiment, the mounting surface  109  is a small plate that extends outwardly from a bottom of each side of the casing  102   a  and which has at least one opening for receiving a screw (see  FIG. 11 ). Thus, each casing (and correspondingly each fixture) can be mounted in place, while the lamp is installed in the fixture. 
   Turning to  FIG. 9 , shown in simplified format is a schematic of the electrical connections and wiring for one fixture  102 . The special power cable  103  runs among the three casings  102   a ,  102   b ,  102   c , and includes five internal wires (shown here as  1 ,  2 ,  3 ,  4 , and  5 ). The first wire  1  is a switched hot line wire. A second wire  2  is a dimmed hot line. Also inside the special power cable  103  are a neutral wire  3  and a ground wire  4 . A fifth wire  5  runs from one lampholder to the ballast  120  and from the ballast  120  to a second lampholder  104 . The cord segments (with male and female plugs)  113  that connect one fixture  102  to an adjacent one, contain the first four wires discussed above. 
   The special power cable  103  can be a flexible molded cable with a flexible jacket  31 , and preferably includes all of the conductors necessary to power the ballasts  120  and correspondingly the lamps  101 . The individual conductive wires  1 ,  2 ,  3 ,  4 ,  5  ( FIG. 10 ) are further insulated using a suitable insulative material  30  inside the flexible jacket  31  and between the insulated jacket of each wire. In accordance with a preferred embodiment, the wire  5  (which connects the lampholders  104  to the ballast  120 ) will, in operation, carry 1000 volts of electricity, and the lower voltage wiring  1 ,  2 ,  3  and  4 , in operation will carry no more than 600 volts (in practice this voltage will almost always be either 120 or 277 volts). The conductors  1 ,  2 ,  3  and  4  are sized to carry the maximum ampacity allowed by the design of the modular connectors  207  and  107 . The insulation of the special power cable  103  and the conductors is a soft durometer polymer, and the stranding and gauge size of the copper wire is selected for maximum flexibility. Because the special power cable  103  is very flexible, it can conform easily to any suitable curvature or lamp design. 
   As shown in  FIGS. 13A-13F , unlike flexible metallic conduits, the special power cable  103  can be curved to any suitable radius without damage (i.e., the flexible metallic will unravel when pulled or overbent). Accordingly, the special power cable  103  can be looped or curved to various radii, and otherwise manipulated to make the overall length of the fixture  102  shorter as necessary to fit the dimensions of a desired system. Unlike flexible non-metallic conduits, the special power cable will not “spring back” when curved into a shape, nor will it retain a curved shape from its coiled packaging, eliminating the possibility of lamp breakage due to torque on the lamp from the “springback” of the conduit. The cable jacket may be made from UV resistant material to prevent degradation caused by ultraviolet (UV) radiation emitted from the tubular lamp. 
   Other exemplary systems are depicted in  FIGS. 14A-C  and  15 A-C.  FIGS. 14A-C  are schematic diagrams showing a 3-lamp assembly (three-color, e.g. red, green and blue, or any other variation of colors or whites) constructed in accordance with the invention.  FIGS. 15A-C  are schematic diagrams showing a 4-lamp assembly (four-color, e.g. Cyan, Magenta, Yellow and white or any other variation of colors or whites, each color separately controllable) constructed in accordance with the invention. It should be understood that these exemplary systems contain fixtures  102 , special power cable  103 , and cord  113  as discussed above, but each system may contain lamps of any shape, size, and color to meet the desired lighting characteristics for the system. The fact that the same fixtures  102  can be used for any of these exemplary systems is an important advantage of this invention. 
   The easy installation of lighting systems, such as exemplary systems  100 ,  200 , is another important advantage of the present invention.  FIG. 16  depicts an exemplary method for installing a lighting system constructed in accordance with the invention. First, at step  401 , lamps  101  are designed and fabricated to meet the particular lighting conditions necessary for a particular project. 
   Next, at step  402 , fixtures  102  are arranged at the project site in the approximate shape of the lamps  101  to be installed. First and second sides of each special power cable section  103  extend from the middle casing  102   b  to each of the end casings  102   a ,  102   c . Because the special power cable sections  103  are flexible, changes in location of the fixtures  102  is not critical as the special power cable  103  can be either adjusted or looped (to reduce the overall length) without sacrificing efficiency (see  FIGS. 12A-12F ). 
   In step  403 , the lamps  101 ,  201  are snapped into place in the corresponding fixtures. Here, the lamp ends (which have integral lamp bases) are snapped into a lampholder within the casings at each end of the fixture. Next, at step  404 , the wire clips  105  are swiveled 90 degrees up from horizontal and into place over the lamp body. As the system  100  begins to take shape, minor adjustments can be made in the positioning of the fixtures  102  until the overall system shape is created. At step  405 , the fixtures are mechanically fastened using the mounting plates  109  attached to the underside of each casing (of which three comprise a fixture). 
   Finally, at step  406 , once each lamp  101  and fixture is fastened in place, the electrical connections between each adjacent fixture  102 ,  202  are completed such that female modular connections  107  are mated with male modular connections  207  to form a continuous fixture array. In addition, the modular female connection end  107  of the lighting array is capped with a cap  108  at a first end, and connected to a power source  106  at a second end. Finally, power may be applied to the system  100 . 
   The above description and drawings are only illustrative of preferred embodiments which can achieve the objects, features, and advantages of the present invention. It is not intended that the invention be limited to the embodiments shown and described herein. For example, the invention has been described with respect to cold cathode lamps, but it may be used with a variety of lighting systems, including standard fluorescent or other tubular lamps. 
   Modifications of the invention coming within the spirit and scope of the following claims are to be considered part of the present invention.