Patent Publication Number: US-8113684-B2

Title: Fluorescent lamp support

Description:
BACKGROUND 
     This application relates to apparatus and methods for supporting and powering fluorescent lamps. In particular, the application relates to apparatus and methods for distributing power from a ballast to a lamp holder. 
     Normally, when a fluorescent fixture is built by a fixture manufacturer, the manufacturer will start with an enclosure (typically sheet metal) and insert fluorescent lamp holders at either end of the fixture a nominal distance apart. The distance will usually depend on the length of fluorescent lamp or tube for which the fixture is designed. When multiple lamps are to be installed, the lamp holders will be positioned across the width of the fixture at nominal distances. Then, a ballast will be mounted to the enclosure in a location that is hidden from the end user. Then wires will be connected from the ballast to each lamp holder (the wires may already be part of the ballast). 
     In order to assemble a fluorescent fixture in this manner, several manual steps need to be performed. There may be numerous wires that connect the ballast to the lamp holders that the factory and installer may have to contend with. This can lead to wiring errors or simply an unappealing installation. 
     Lamps that are assembled in this manner may require features that are designed for a predetermined width-wise placement of the lamps. For example, the installation of lamps at 2-inch center-to-center distances would require a crossbar configured to engage lamp holders, and provide power, at those locations. If it were then desirable to manufacture a fixture having lamps at different center-to-center distances, a different crossbar would be required. 
     It would be desirable, therefore, to provide apparatus and methods that reduce the likelihood of manufacturing errors. 
     It would also be desirable, therefore, to provide apparatus and methods that reduce the requirement for fixture components having different center-to-center distances. 
     SUMMARY OF THE INVENTION 
     It is an object of the invention to provide apparatus and methods that reduce the likelihood of manufacturing errors. It is a further object of the invention to provide apparatus and methods that reduce the requirement for different fixture components having different center-to-center distances. 
     Accordingly, apparatus and methods for supporting and energizing a fluorescent lamp are provided. The apparatus may include a ballast, a rigid power distribution unit; and a lamp holder. The lamp holder may be in electrical communication with the rigid power distribution unit such that when the lamp holder supports a lamp, the lamp holder is configured to provide power from the rigid power distribution unit to the lamp. Some embodiments, therefore, may not require the use of wires to transmit power from the ballast to the lamp holder. The lamp may be any suitable lamp, including T5, T8 and T12 lamps. The rigid power distribution unit may include a track that has conducting rails for supplying power to lamp holders. The track may be used to position lamp holders at any desired spacing so the track may be used in connection with fixture designs requiring different center-to-center lamp spacing. 
     In some embodiments, the rigid power distribution unit may include a printed circuit board. The lamp holder may clamp onto or be otherwise mechanically and electrically connected to the printed circuit board and draw power from it. The printed circuit board may have traces for each lamp holder. In some embodiments, conductive buses may be used either as traces on the printed circuit board or separate from the printed circuit board. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The objects and advantages of the invention will be apparent upon consideration of the following detailed description, taken in conjunction with the accompanying drawings, in which like reference characters refer to like parts throughout, and in which: 
         FIG. 1  is a schematic diagram of an apparatus in accordance with the present disclosure; 
         FIG. 2  is a perspective view of other apparatus in accordance with the present disclosure; 
         FIG. 3  is a different perspective view of the apparatus shown in  FIG. 2 ; 
         FIG. 4  is a side view, corresponding to the view along lines A-A shown in  FIG. 1 , of apparatus in accordance with the present disclosure; 
         FIG. 5  is a perspective view of other apparatus in accordance with the present disclosure; 
         FIG. 6  is a top view of the apparatus shown in  FIG. 5 ; 
         FIG. 7  is a partial cross-sectional view taken along lines  7 - 7  shown in  FIG. 6 ; and 
         FIG. 8  is a perspective view of still other apparatus in accordance with the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Apparatus and methods for supporting and powering a fluorescent lamp are provided. The apparatus preferably includes a ballast, a rigid power distribution unit; and a lamp holder. The ballast receives power from a standard power line, such as a 110 VAC power line or any other suitable power line. The ballast preferably has a reactive coil and a power conditioner for providing appropriate current to the lamp via the rigid power distribution unit. The rigid power distribution preferably distributes the power to one or more lamp holders. The lamp holders preferably are directly supported by the rigid power distribution unit. 
     The lamp holders shown and described herein may hold and excite one end of a tube-shaped lamp. Generally, when long tubes are used, two opposing lamp holders (one at each end of the lamp) are usually required—one to support and excite each end of the lamp. Each of the opposing lamp holders may be supported by a rigid power distribution unit. 
     The lamp holder may is in electrical communication with the rigid power distribution unit such that when the lamp holder supports a lamp, the lamp holder is configured to provide power from the rigid power distribution unit to the lamp. Some embodiments, therefore, may not require the use of wires to transmit power from the ballast to the lamp holder. The lamp may be any suitable lamp, including T5, T8 and T12 lamps. 
     In some embodiments, the rigid power distribution unit includes a track that has conducting rails for supplying power to lamp holders. The rails may run along a portion of the track so that lamp holders engaging the portion may receive power from the rails. The track may include a slot or edge along which the lamp holders may slide. The track may include one or more detents to maintain a lamp holder in a position along the track. In manufacturing, the track may be used to position lamp holders at any desired spacing so the track may be used in connection with fixture designs requiring different center-to-center lamp spacing. The spacing may optionally be standardized to accommodate one or more of the various industry standards. 
     In some embodiments, a method for manufacturing a fluorescent lamp support includes mating a ballast connector to a rigid power distribution unit connector to form an electrical connection between them. The method further includes sliding a lamp holder from a first position in the track to a second position in the track. The rigid power distribution unit may include a track along which the lamp holder may slide. The rigid power distribution unit may include conducting rails for providing power to the lamp holder at different positions along the track. 
     In some embodiments, the rigid power distribution unit may include a printed circuit board. The lamp holder may clamp or be otherwise mechanically and electrically secured to the printed circuit board and draw power from it. The printed circuit board may have traces from each lamp holder to be plugged into it. The printed circuit board may be part of a ballast printed circuit board assembly. The lamp holder printed circuit board may be connected to the ballast by any suitable connectors, such as male/female connectors. The ballast may be located either inside or outside a housing that may enclose the rigid power distribution unit. In some embodiments, the printed circuit board may be in electrical communication with the lamp holder via flat cable and male/female connectors. 
     In some embodiments, the rigid power distribution unit includes rails made of any suitable conducting metal such as copper, silver, brass or the like. For example, the conducting metal may be an abrasion-resistant metal, such as brass. The rigid power distribution unit may include a housing. The housing may be made of plastic, metal or other suitable enclosure material. 
     In some embodiments, the rigid power distribution unit includes a track. The track may be open on one or both ends for insertion of a lamp holder. An open end of the track may be blocked by a skirt after insertion of one or more lamp holders. The skirt may include any suitable material, such as a polymer or elastomer such as ethylene acrylic elastomer (“AEM”) such as that available under the trademark “VAMAC” from E. I. DuPont and Co., located in Wilmington, Del. The material may be an elastomer, such as neoprene. 
       FIGS. 1-8  show illustrative embodiments and features of the invention. 
       FIG. 1  shows schematically lamp support  100 . Lamp support  100  includes power input leads  102 , ballast  104 , rigid power distribution unit  106  and lamp holders  108 . Lamp support  100  also includes rigid power distribution unit  110  and lamp holders  112 . Each of lamp holders  108  has a facing lamp holder  112 . Together, a pair of lamp holders—one  108  and a corresponding  112 —hold a fluorescent lamp or tube at its ends. Lines L 1  represent the center lines of lamps that may be installed between corresponding lamp holders. Adjacent lines L 1  may be separated, for example, by center-to-center distance C 1 . 
     Rigid power distribution units  106  and  110  may be affixed to an enclosure (not shown). Ballast  104  receive power via leads  102  and provide the power to lamp holders  108  via rigid power distribution unit  106 . Rigid power distribution unit  106  may be connected to ballast  104  by connector  114 . Connector  114  may be a pin connector or any other suitable connector. Rigid power distribution unit  110  may receive power from ballast  104  via leads  116 . 
     One or both of rigid power distribution units  106  and  110  may include a printed circuit board for delivering power along traces or conductors to lamp holders  108  and  112 , respectively. Positive and negative conductors, each corresponding to one of leads  102  and one of leads  116 , may be provided along edges  118  and  120 , respectively, of rigid power distribution units  106  and  110 . The positive and negative conductors may match corresponding positive and negative terminals of lamp holders  108  and  112 . The positive and negative conductors may be arranged in any suitable configuration. For example, in some embodiments, the positive and negative conductors may be, respectively, on top and bottom of edges  118  and  120 . In some embodiments, both the positive and negative conductors both may on one side (top or bottom) of edges  118  and  120 . The positive and negative conductors may be routed through their respective rigid power distribution units in any suitable manner to deliver power to positions on edges  118  and  120  where power is or may be desired. In some embodiments, power may be routed to points on edges  118  and  120 . In some embodiments, power may be routed to elongated segments of edges  118  and  120 . The segments may allow lamp holders  108  and  112  to be positioned with greater flexibility. 
     In some embodiments the segments may be sufficiently elongated that the lamp holder may be attached subject to an appropriate mechanical tolerance, but sufficiently restricted such that a properly installed lamp holder will shield the segment from contact with other objects. In some embodiments, the traces may be below the surface of the rigid power distribution unit. In those embodiments, the lamp holders may be provided with crimps or fasteners to make electrical contact with the traces. Rigid power distribution units  106  and  110  should be sufficiently rigid to mechanically support lamp holders  108  and  112  such that corresponding lamp holders can support and power a lamp. 
       FIG. 2  shows in perspective, from below (in an operational orientation), illustrative lamp support  200 . Lamp support  200  includes ballast  202 . Ballast  202  connects via connector  204  to rigid power distribution unit  206 . Rigid power distribution unit  206  may mechanically support lamp holders  208  via a press fit of lamp holders  208  onto edge  212 . Edge  212  includes conductors to provide power to electrical terminals (not shown) of lamp holders  208 . Rigid power distribution unit  206  may be a printed circuit board that has traces that deliver power to lamp holders  208 . Lamp holders  208  may include pin slots  210  for receiving pins of fluorescent lamps. 
       FIG. 3  shows lamp support  200 , in perspective, from above (in an operational orientation). Slots  214  in lamp holders  208  may be press fit onto edge  212 . Slots  214  may include electrical terminals for transmitting power from edge  212  to lamps, when lamps are installed in lamp holders  208 . 
       FIG. 4  shows illustrative lamp support  400  in side view. The view shown in  FIG. 4  may correspond to a side view along direction A-A, shown in  FIG. 1 . Lamp support  400  includes ballast  402 . Lamp support  400  include rigid power distribution unit  404 . Ballast  402  and rigid power distribution unit  404  may be electrically joined by connector  406 . Lamp holder  408  may have groove  410  for mating with edge  412  of rigid power distribution unit  404 . Groove  410  may include terminals  414  and  416  for contacting traces  418  and  420 , respectively, on edge  412 . Slot  422  may be provided for testing circuit continuity via lamp holder  408 . 
       FIG. 5  shows illustrative lamp support  500 . Illustrative lamp support  500  includes ballast  502  and rigid power distribution unit  504 . Lamp holders  506  are slidably mounted in track  508  of rigid power distribution  504 . Detents, such as detents  510 , or any other suitable detents, may be present in or about track  508  to provide determined locations at which lamp holders  506  may be maintained. Ballast  502  may receive power via leads (not shown). Ballast  502  may provide power to rigid power distribution unit  504  via a connector (not shown). Ballast  502  may provide power to a distal power distribution unit (not shown) via leads (not shown). The distal power distribution unit may support a distal end of one or more lamps. (Rigid power distribution unit  504  may be referred to as a “proximal” power distribution unit, because it is adjacent ballast  502 .) 
     Rigid power distribution unit  504  may be mounted to plate  512 . Plate  512  may have any suitable features for attaching lamp support  500  to a lamp enclosure (not shown) or any other suitable structure. 
       FIG. 6  shows a perspective view of lamp support  500 . Lamp holders  506  may include slots  516  for receiving terminal pins from a lamp. (It will be appreciated that there are different arrangements by which lamp holders may mechanically and electrically engage lamps. Any suitable lamp holder may be used in conjunction with the lamp supports shown and described herein.) Test holes  518  may optionally be present in lamp holders  506  to receive continuity test probes. 
       FIG. 6  also shows lamp center lines L 2 , which correspond to lamps that may be installed in lamp support  500 . Distance C 2  between adjacent lines L 2  may be adjusted by sliding lamp holders  552  and  554 . By adjusting C 2  during a manufacturing or assembly process, lamp support  500  may be used for different luminaires having different center-to-center lamp distances. 
       FIG. 7  shows additional detail of the lamp holders  506  and their mechanical and electrical interface with rigid power distribution unit  504 . Slots  516  may open up to a cavity (not shown) for receiving the end of a lamp. Contact pin guide  517  may guide pins at the end of the lamp during installation of the lamp in lamp holder  506 . Lamp holder  506  may include groove  523 , which may be defined at least in part by bosses  520  and  522 . Groove  523  may receive tongue  521  of rigid power distribution unit  504 . Knee  525  at the base of lamp holder  506  may occupy groove  508 . Any suitable adjacent surfaces between lamp holder  506  and rigid power distribution unit  504  may be used for transferring electrical power between the two. For example, interfacial surfaces  524  and  526  may include electrical contacts for transferring the power. In general, positive and negative contact will be present on lamp holder  506  and rigid power distribution unit  504 . In some embodiments, the positive and negative contacts may be in opposite sides of a structure, such as tongue  521 . In some embodiments, the positive and negative contacts may be separated from each other, but on the same interfacial surface. 
       FIG. 8  shows illustrative lamp support  800 . Lamp support  800  includes ballast  802  in a perpendicular orientation with respect to rigid power distribution unit  804  and plate  812 . Lamp holders  806  are slidably mounted in track  808 . It will be appreciated that the ballasts shown and described herein may be mounted in any suitable orientation with respect to a corresponding rigid power distribution unit. 
     Thus, apparatus and methods for supporting and energizing a lamp have been provided. Persons skilled in the art will appreciate that the present invention can be practiced by other than the described embodiments, which are presented for purposes of illustration rather than of limitation, and the present invention is limited only by the claims which follow.