Abstract:
A housing for a flourescent tube wherein the end caps are formed to interengage the end caps of an adjacent housing thereby enabling the formation of a variable length display panel. A large area advertisement can be removably secured to the panel which provides backlighting. Each end cap is provided with a removable section to permit access to the housing interior and replacement of the flourescent tube or ballast therein.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]    The present application is based on provisional patent application Serial No. 60/184,286, filed Feb. 23, 2000. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    This invention relates to a novel housing structure for a light tube. The structure enables housings to be removably secured one to another for the formation of a lighted display panel.  
           [0003]    In the field of display advertising, the use of large area lighted display panels has become commonplace. The display panel is typically comprised of a number of flourescent tubes mounted in a display frame with a display surface that receives the film having the advertisement thereon. The display panel provides the backlighting for the film and aids in creating a strong commercial impression.  
           [0004]    The lighted display panel of fixed dimensions has a multitude of uses including stand-alone displays as well as segmented wall displays incorporated in the modular equipment used in exhibitions, conventions and seminars. The fixed dimensions of these panels reduce the flexibility of use. The participants in exhibitions and the like have varying needs dictated by the message to be displayed, the function to be performed in a modular display and the size of the allotted floor space. Thus, the need for lighted displays of variable dimensions is present.  
           [0005]    The duration of exhibitions, conventions and seminars is normally quite limited. As a result, the set up and take down of modular walls and associated displays takes place repeatedly. A major goal of the provider of a modular display is to have straight forward assembly routines which can be performed by workers having minimal training. Further, the ability to assemble and disassemble without the need to use elaborate tools is important.  
           [0006]    The importance of utilizing a portable display panel that can be free-standing and setup without special tools is recognized in U.S. Pat. No. 3,748,455 to Welton which describes a foldable light box with back supports that open to support the light box in a vertical position. The boxes are attachable at their edges to provide an elongated display. Each box nests with another for stacking in a storage position. An individual box contains a number of flourescent tubes along with the associated electrical equipment. The overall volume and weight of a light box make it difficult to handle and transport.  
           [0007]    Another type of display device is disclosed in U.S. Pat. No. 4,864,475 to Jung wherein a rigid light box contains a plurality of horizontal tubes closely positioned to provide a more uniform back lighting for a display. The individual tubes are provided with colored tubing for display purposes. The display device is used for a single display and is not interconnected. The Lotter el al. U.S. Pat. No. 5,301,447 is directed to a rigid light box for housing a lighting module and having a number of flourescent tubes. No provision is made for attaching the light box to adjacent light boxes. The device is constructed for attachment to a standing wall.  
           [0008]    A backlighting light fixture which avoids the use of unwieldy, heavy and expensive rigid light boxes is shown in U.S. Pat. No. 5, 584,566 to Bowman et al. A series of interconnected lightweight frames is provided with a plurality of individual transparent of translucent panels. A bowed reflector carrying a flourescent light and ballast is secured to each frame. A reflector is removably attached to each frame section. The use of multiple reflectors for the individual sections of a rigid frame adds time for assembly and results in a multiplicity of parts that need to be handled for shipment to another location. The flourescent tubes are detached from the reflector prior to being stowed.  
           [0009]    The above-noted devices are concerned with fixed dimension light boxes or frames. The boxes and frames are stand alone units limiting the ability of the space planner to configure a particular area to the best advantage. The weight, complexity and expense of these units is discussed in the Bowman &#39;566 patent reference.  
           [0010]    Accordingly, the present invention is directed to the provision of a flourescent light tube housing that can be readily interconnected with adjacent housings to provide a display of variable length. The housings are secured one to another by end caps which engage to maintain a desired angle therebetween as well as to secure adjacent housings. Thus, the present invention permits the formation of lighted displays of variable shape and length. The ability to assume a variety of shapes makes the present invention substantially more versatile when contrasted with the capability of rigid light boxes.  
         SUMMARY OF INVENTION  
         [0011]    The present invention is directed to a light tube housing for facile interconnection with adjacent housings to provide the back lighting for a lighted display of variable length and contour.  
           [0012]    The novel light tube housing includes a light transmissive tube for containing a flourescent tube. The tube is provided with end caps which are comprised of fixed and removable sections. The fixed sections are securely attached to the tube. Each fixed section and each removable section are semicircular. Each fixed section contains a central stem which nests within the central stem of a removable section. The stems are hollow to receive an electrical socket therein. The flourescent tube is mounted in the sockets. Access to the flourescent tube is provided via the removable section of the upper end cap.  
           [0013]    The end caps contain a plurality of outward protrusions radially spaced on the outer surface. The lateral extensions formed by the protrusions provide a peripheral shoulder which contacts the end of the tube and maintains the relative position of end cap and tube. The outer protrusions are provided with first engaging means to secure adjacent housings one to another and to enable a display film to be secured to an array of housings. The region between protuberances is provided with a second engaging means, in the nature of a hook and loop material, to secure adjacent housings.  
           [0014]    The protrusions on the end caps register with the regions in between the protrusions on the end cap of an adjacent housing and define the angular relationship therebetween thereby permitting the formation of arrays of different shape and length. A power receptacle is located within the housing to permit electrical interconnection between adjacent housings in an array.  
           [0015]    Further features and advantages will become more readily apparent from the following detailed description of a preferred embodiment of the invention when taken in conjunction withe the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]    [0016]FIG. 1 is a view in perspective showing an array of housings with the display film partially folded back.  
         [0017]    [0017]FIG. 2 is an exploded view showing the base end cap of the preferred embodiment.  
         [0018]    [0018]FIG. 3 is an exploded view showing the top end cap of the preferred embodiment.  
         [0019]    [0019]FIGS. 4A and 4B are side views in section of the end caps taken through the regions between protrusions and through the protrusions respectively. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0020]    Referring now to FIG. 1, a sinuous array of individual light tube housings  11  is shown with an electrical connector  12  available for connection to an external power source. An overlying film  14  containing the advertising message is shown partially applied to the array. The film  14  is light-transmissive film having bands  15  of hook or loop type fastener located along the top and bottom edges for engagement with mating bands of fasteners located on outward convex protrusions provided on the upper end cap protrusions of the housings and to mating bands of fasteners affixed to the tubular surrounds  17  shown in FIG. 3, near their lower edges. In other embodiments, use is made of fastener bands provided on the base end caps to increase the height of the film affixed to the array. The array of FIG. 1 shows the electrical connections to adjacent housings occurring through openings in the tubular surrounds. As will be noted from the description of the end caps shown in FIGS. 2, 3 and  4 , the connections can be provided through notched openings in the protrusions of the bottom end caps.  
         [0021]    The constructional features of the individual housing are described in connection with the exploded views of the end caps and adjacent components in FIGS. 2 and 3. In the matter of the molded end caps, two segments  20 ,  21  are formed for both top and bottom of the housing. A fixed or non-removable segment  20  equipped for use as part of a bottom end cap is provided with an electrical housing  22  and affixed thereto by flanges. Conduit  24  is secured at an opening in the top of the housing and extends upwardly to the top end cap of FIG. 3 and spaced in proximity to the light tube to reduce its effect on the transmitted light. The housing  22  contains the receptacle for the electrical connection to an adjacent housing accessible either through the underside of the end cap or a hole in the tubular surround, the external connector  26  for coupling to the next adjacent housing, a circuit breaker and a port  28  which carries the conductors through a like port to ballast  30  contained in housing  31 . The ballast housing is affixed to the removable segment  21  of the lower end cap and coupled to housing  22  by a shared grommet  25 . Both sections  20 ,  21  of the end cap are provided with centrally located stems  27 ,  29  which nest one to another as further shown in the cross sections of FIGS. 4A and 4B. The stem  27  of the fixed segment  20  provides the support for a spring-loaded socket  32 , typically fastened by countersinking holes for engagement with the stem. The segments of both top and bottom end caps are connected by threaded fasteners to the adjacent surround and are positionally maintained by the nesting of their respective stems. The outer surface of the stems in the fixed end caps is provided with a circumferential groove  58 , seen in FIG. 4B, which receives an o-ring for frictional engagement with a protective cover (not shown).  
         [0022]    The top end cap is shown in FIG. 3 wherein a non-spring type socket  40  for a flourescent tube is mounted to the fixed segment  41  of the top end cap. Since conduit  24  terminates at segment  41 , a cover plate  39  is provided over the connection to the socket  40  and maintained in position by the stem of the removable segment. The segment  42  is removably attached to the surround and is provided with a central stem that nests on the stem of the fixed segment. A standard flourescent tube  43  is located between the sockets in the stems of the fixed segments of the end caps. Surrounding the tube  43  is a translucent polycarbonate surround or tube  44  which diffuses the light and protects the internal parts in the housing. The surround  44  provides the surface upon which the message film is placed with the flourescent tubes providing the back lighting. Should a tube or ballast need replacement, the removable segment of the top end cap provides access to the interior of the housing.  
         [0023]    The top and bottom ends are provided with convex outward protrusions shown as  51  on the fixed segment and  52  on the removable segment of the top end cap. Like protrusions  53  and  54  are provided on the segments of the bottom end cap. The protrusions form shoulders  60  for frictional engagement with the outer tube  44  to enhance the structural rigidity of the housing and aid in alignment of the parts.  
         [0024]    The protrusions are used to align adjacent housings to form an array of curved or angular shape. Each protrusion is provided with a region containing a hook or a loop fastener material. The intervening concave regions between the protrusions are provided with the mating fastener material to aid in establishing a locking relationship between adjacent housings. The end caps of adjacent housings serve as toothed gears to define a desired position with the fastener material serving to maintain the position.  
         [0025]    The end caps shown have two segments, each having four outward protrusions. In use, at least one protrusion with its fastener surface is in alignment with the display surface of the array. This surface can be utilized to support the planar display material thereon in place of the tubular surrounds. The display material can be installed and removed readily for future use. A substitute display can then be secured on the array without disassembling the array.  
         [0026]    In the afore-described embodiment which has been successfully used for a commercial display, the flourescent lamp used is a Type T8 with a polycarbonate surround of 6 inch diameter therearound. The surround length is 91.5 inches and contacts the shoulders of eight protrusions at each end cap. Each shoulder is ¼ inch to accommodate the tube wall of {fraction (3/32)} inch width.  
         [0027]    The end caps are formed of molded plastic with a {fraction (3/16)} inch thickness. The stems are tapered to facilitate nesting with the outer stem varying from 2 {fraction (3/16)} down to a 2 {fraction (1/16)} inch width. The lamp holder which is commercially available compresses {fraction (7/16)} inch to permit a ⅜ inch lap pin at top to disengage from the top fixed lamp holder for replacement.  
         [0028]    While the foregoing description has been with reference to a particular embodiment of the invention, is to be noted that variations and modifications may be made therein without departing from the scope of the invention.