Abstract:
Connector for a discharge lamp and ballast assembly, as well as a lamp assembly including the connector. The connector is a conductive ribbon that includes a plurality of pinch or wedge-shaped wire slots for receiving lead wires from the discharge lamp and from the power supply. The connector is made of a material and is suitably shaped to provide flexibility to accommodate thermal expansion and contraction of the lamp, yet provide for proper positioning of the lamp in a reflector housing or the like. Disassembly of the connections and replacement of the lamp is facilitated and does not result in permanent damage to the lamp.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    Neon lamps are typically elongated tubes with diameters ranging from 5 millimeters to an inch. In view of their relatively low power consumption and long operating life, neon lamps are often used in automotive applications, such as top-brake lights or direction (turn) signal lamps. Neon lamps as well as other discharge lamps are ignited with high voltage that depends in part on the overall length of the lamp. Voltages in the kilovolt range are common.  
           [0002]    A silicone lead wire is typically required to connect discharge lamps to high voltage sources. In addition, a resilient boot, typically made of molded silicone rubber, is used to provide a moisture-proof seal for the connection between the contact pin of the lamp and an electrical terminal supplying power to the lamp. The boot also serves to accurately locate the discharge lamp in the housing, cushion the lamp against shock and vibration, and provide a flexible expansion and contraction joint in the event of thermal expansion or contraction. U.S. Pat. No. 5,610,472, the disclosure of which is hereby incorporated by reference, discloses such a boot in connection with a discharge lamp connector.  
           [0003]    However, for low voltage applications, such a molded silicone boot and silicone lead wire are not cost-effective. In addition, the molded silicone boot has high insertion stress to the lamp press area, and does not allow for removal once the connector has been installed. Removal would permanently damage both the lamp and connector. Elimination of the silicone boot would eliminate the mechanical insertion force, and would allow for removal of the lamp without causing permanent lamp damage.  
           [0004]    It is therefore an object of the present invention to provide a discharge lamp connector that allows for disassembly of the connection and replacement of the lamp without permanently damaging any of the component parts of the assembly.  
           [0005]    It is a further object of the present invention to reduce or eliminate the mechanical insertion force necessary when a conventional silicone sealing boot is present.  
         SUMMARY OF THE INVENTION  
         [0006]    The problems of the prior art have been overcome by the present invention, which provides a connector for a discharge lamp and ballast assembly, as well as a lamp assembly including the connector. The connector is a conductive ribbon that includes a plurality of pinch or wedge-shaped wire slots for receiving lead wires from the discharge lamp and from the power supply. The connector is made of a material and is suitably shaped to provide flexibility to accommodate thermal expansion and contraction of the lamp, yet provide for proper positioning of the lamp in a reflector housing or the like. Disassembly of the connections and replacement of the lamp is facilitated and does not result in permanent damage to the lamp. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]    [0007]FIG. 1 is a perspective view of one embodiment of the connector in accordance with the present invention;  
         [0008]    [0008]FIG. 2 is front view of a wire connector in accordance with the present invention;  
         [0009]    [0009]FIG. 3 is a top cross-sectional view of a wire connector shown with a wire inserted in accordance with the present invention;  
         [0010]    [0010]FIG. 4 is a cross-sectional view of the connector held by a boss in accordance with the present invention; and  
         [0011]    FIGS.  5 A- 5 E are schematic layouts of alternative wire connectors in accordance with the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0012]    Turning first to FIG. 1, there is shown a connector  10  in accordance with one embodiment of the present invention. Also shown is a portion of discharge lamp  12 , having at least one electrical wire lead  13 , and a second wire lead  14  in electrical communication with a power supply (not shown) to supply power to the discharge lamp  12 . In general, the discharge lamp has an elongated configuration, although the present invention is not so limited. The discharge lamp  12  is preferably a neon lamp, although other discharge lamps are operable with the connector of the invention and are within the scope of the present invention.  
         [0013]    In the embodiment of FIG. 1, the connector  10  is a single piece conductive ribbon in a cursive pattern shaped as the arabic numeral “6”, having an end  20 A facing the lamp  12 , an opposite end  20 B spaced from end  20 A and joined to end  20 A by a first side  20 C, and a second open side  20 D opposite side  20 C. Side  20 D includes a first portion  21 A extending from end  20 A substantially parallel to side  20 C, and a second portion  21 B bent at elbow  24  towards side  20 C at about a 90° angle to first portion  21 A. Preferably the second portion  21 B terminates in a free end  22  as shown, and extends a sufficient length towards the side  20 C to accommodate a wire slot  30 B as discussed in greater detail below. Side  20 D also includes a third portion  21 C extending from end  20 B substantially parallel to side  20 C. Third portion  21 C terminates in free end  23 . Free end  23  and elbow  24  define between them an aperture  25  as shown.  
         [0014]    The configuration of the connector  10  of FIG. 1 allows for spring-like flexibility, so that the connector  10  can accommodate thermal expansion and contraction of the discharge lamp and associated components. In addition, the flexibility or spring-like action of the connector  10  will allow the discharge lamp  12  to be properly positioned (e.g., centered) in a reflector housing or other assembly. Suitable materials of construction for the connector  10  include electrical conductors such as metal, stainless steel, plated phosphor, plated copper, plated brass, bronze, etc., preferably those which are rust-proof. Although flexible, the conductor  10  is sufficiently rigid or stiff to receive and grasp wires as discussed below.  
         [0015]    The connector  10  includes a plurality of wire slots  30  formed in respective side walls of the connector, shown in greater detail in FIGS. 2 and 3. Preferably each wire held by the connector  10  is inserted into two such slots  30 , although those skilled in the art will appreciate that fewer or more could be used. Each wire slot  30  is designed with opposed cutting edges  31 ,  32  (FIG. 3), configured as a wedge-shape so that the space between the edges  31 ,  32  is slightly smaller than the outer diameter of the wire to be inserted in the slot  30 . Upon insertion of the wire into the slot  30 , the cutting edges  31 ,  32  displace the outer insulation  33  of the wire and contact the wire conductor  34  as shown in FIG. 3, creating an electrical connection. The wire remains removably secured in the wire slot as a result of the press fit created. By spreading the wire slots, the lamp or power lead easily can be removed, and the wire slots can then be re-pressed together for further use.  
         [0016]    In order to facilitate insertion of the wire into each slot  30 , preferably the slot is formed with an entry that is wider than the outer diameter of the wire. For example, the slot  30  can include angled sides  35 ,  36  which converge towards each other in the direction towards the bottom  36  of the slot  30 , which bottom is preferably closed, as best seen in FIG. 2. In this embodiment, the two angled sides  35 ,  36  converge to the extent that the narrowest distance between them is smaller than the outer diameter of the wire in order to displace the insulation  33  as discussed above, and thereby create electrical communication between the conductor  34  and the connector  10 .  
         [0017]    In the particular embodiment illustrated in FIG. 1, the lamp lead  13  is pressed into wire slots  30 A and  30 B, and the power lead  14  is pressed into wire slots  30 C and  30 D. The contact edge of the slots cuts through the insulation in the wires, creating electrical communication between the conductor in the wires and the connector  10 . The connector thus allows for rapid coupling and decoupling of the leads, and disassembly of the connections and lamp replacement without permanent damage to the lamp itself. The wire slots  30  do not lose their functionality even after numerous coupling and decoupling operations. The leads need not be perpendicular to each other.  
         [0018]    Turning now to FIG. 4, a connector  10  is shown held in a boss  40  cavity in a housing which can be made from a rigid plastic such as polycarbonate. The cavity of the boss  40  is shaped to hold the connector  10  yet allow the flexibility of the connector  10  to function and thereby accommodate thermal expansion or contraction of the lamp  12  with respect to the lamp housing. More specifically, the boss secures only a portion of connector  10 , preferably a portion of the connector remote from the lamp  12 , thereby allowing the remaining portion of the connector to flex as the lamp  12  expands or contracts. The connector  10  can be held in place in the boss  40  by any suitable means, including ridges, grooves or other similar latching features within the skill in the art.  
         [0019]    As is apparent from FIG. 4, the location of the wire slots  30  is not critical; in the embodiment of FIG. 4, two such slots are formed in longitudinal side member  20 C′, one for lamp lead  13  and the other for power lead  14 . In addition, bent portion  21 B′ is bent more than 90° (relative to side  21 A′), allowing the lamp lead  13  to be secured in three substantially linearly aligned wire slots  30 . Since the wire leads are typically flexible, the wire slots  30  need not be linearly aligned, however.  
         [0020]    FIGS.  5 A- 5 E illustrate other possible configurations of the connector  10 , including a letter a letter “S” shape (FIGS. 5A and 5B), and a letter “B” shape (FIGS. 5C and 5D), and a letter “W” shape (FIG. 5E). Thus, additional bends may be added to the connector to provide for increased flexibility and to form different sized connectors. Equivalent patterns may be similarly devised. Those skilled in the art will appreciate that the location of the lamp wire lead  13  and wire lead  14  in electrical communication with the power supply can be reversed.