Abstract:
A flexible strand lighting apparatus ( 10 ) for ornamental illumination particularly in environments subject to moisture, with a power cord ( 12 ) that connects to a supply of electrical current and a moisture-resistant connector ( 30 ) with a pair of members ( 42, 44 ) at an opposing distal end in electrical communication with the electrical connectors. A tubular light strand ( 14 ) has two electrical conductors ( 54, 56 ) that connect in series to a plurality of spaced-apart light sources ( 52 ). A second moisture-resistant connector ( 58 ) is molded to and integral with the light strand ( 50 ) and includes a pair of second members ( 64, 66 ), which matingly engage with the members ( 42, 44 ) of the first connector ( 30 ) when the first and the second connectors join together in a moisture-resistant connection for communicating electrical current to the light sources ( 50 ).

Description:
TECHNICAL FIELD  
         [0001]    The present invention relates to lighting devices. More particularly, the present invention relates to lighting apparatus having a plurality of bulbs spaced-apart within a flexible strand particularly useful for wet locations illumination and lighting effects.  
         BACKGROUND OF THE INVENTION  
         [0002]    Lighting fixtures are increasingly being used for ornamental and lighting effects with buildings, roadways, and landscaping. Lighting devices that are provided for ornamental effects include a connector to a source of electrical current, a plurality of lighting fixtures with lamps or other bulbs which emit light from the fixtures, and wiring that connects the fixtures to the supply of electrical current. The supply of electricity may be high voltage (120 volt, alternating current) or low voltage (12 volt, direct current). Generally, the low voltage lighting systems are more easily installed, as compared to high voltage systems. These low voltage systems typically operate with transformers which connect to a supply of high voltage. The transformers convert the voltage to direct current which is communicated through the wires to the light bulbs. Low voltage lighting systems provide a number of advantages. Because the current is low voltage, the electrical connections of the wiring do not require special electric junction boxes. Special conduit is generally not required for the wiring, and the wiring may be exposed. Preferably the wiring is placed away from traffic areas or buried underground without conduits. Low voltage lights generate little heat and so are appropriate for use mounted to wooden surfaces.  
           [0003]    While the low voltage lighting systems provide illuminative effects, the brightness of the lighting has not been entirely satisfactory. Generally, the lights are limited in wattage, typically commercially to about 20 watts per bulb. Also, the use of transformers is not entirely satisfactory. Transformers are subject to radio frequency interference (RFI) which may cause the lights to flicker or dim. Transformers are generally bulky and often require special mounting. The total combined wattage of the lamps operated by the transformer cannot exceed the output of the transformer. Nor do the transformers deliver the full rated wattage to the lamps. As the distance increases between the lamp and the transformer, the lumen output decreases.  
           [0004]    In contrast, lighting systems with high voltage 120 volt alternating current generally do not limit the number of lamps used in the application. Lumen output from the lamps remains substantially constant independent of the length of the wires. The lamps receive full wattage capacity. These systems, however, require insulatedjunction boxes to make electrical connections and the wiring passes through insulated conduit.  
           [0005]    One illuminative lighting apparatus is known as rope lighting or “cord” lights. The term “rope lighting” refers to the rope-like, flexible strand or cord appearance and handling characteristics of the lighting apparatus. This type of lighting apparatus consists of a translucent or transparent elongate flexible cord which encloses a plurality of spaced-apart low wattage bulbs. The cord includes a pair of electrical conductors for communicating electricity from a source to the light bulbs in series. The cord is approximately one half inch in diameter and is readily attached with clips to outdoor banisters, rails, steps, decking and the like, and indoors as well. Some types of awnings have open slots which grippingly receive the elongate cord. The flexible rope lighting is provided in an elongated length which is cut to length at predetermined intervals. End caps are placed on the cut ends to close the cord. Several lengths of the cord may be joined together as a continuous lighting strand. Adjacent cut ends link together with tubular connectors. One end connects to a source of electricity.  
           [0006]    While rope lighting provides illuminative effects for buildings, driveways, walkways, and landscaping, there are drawbacks to its use. The cut ends of the cord lighting in combination with the end caps are difficult to make waterproof. Because these rope lights use non-shunting bulbs, when one bulb burns out, a section of a plurality of bulbs burn out. In response, the burned-out section is cut away and a new section inserted with the connectors. However, this makes a potentially dangerous electrical connection in that the connections of adjacent cut ends, as described above, are difficult to make waterproof.  
           [0007]    Accordingly, there is a need in the art for an improved flexible strand lighting apparatus resistant to moisture penetration of connections. It is to such that the present invention is directed.  
         BRIEF SUMMARY OF THE PRESENT INVENTION  
         [0008]    The present invention meets the need in the art by providing a flexible strand lighting apparatus for ornamental illumination particularly in environments subject to moisture, in which the light apparatus includes a power cord having electrical connectors at a first end for connecting to a supply of electrical current. A first moisture-resistant connector is molded to and integral with the power cord at an opposing distal end. The first connector includes a pair of members in electrical communication with the electrical connectors. A light strand has a tubular body with a core extending therethrough having two electrical conductors engaged in series to a plurality of spaced-apart light sources. A second moisture-resistant connector at a distal end of the light strand is molded to and integral with the light strand and includes a pair of second members in electrical communication with the electrical conductors. The second members are adapted for mating engagement with the members of the first connector. A first engaging member associated with the first connector of the power cord and a second engaging member associated with the second connector of the light strand provide for engaging the first and the second connectors in a moisture-resistant junction to place the second members in the second connector in electrical communication with the members in the power cord for communicating electrical current to the light sources. The first and second connectors, being joined together, restrict moisture penetration into the junction that communicates electrical current to the light sources.  
           [0009]    Objects, advantages, and features of the present invention will become apparent upon a reading of the following detailed description, in conjunction with the drawings and the appended claims. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    [0010]FIG. 1 is a perspective view of a rope lighting apparatus according to the present invention.  
         [0011]    [0011]FIG. 2 is a perspective, partially cut-away view of a first connector with a molded cap partially cut away, for illustrating features of the rope lighting shown in FIG. 1.  
         [0012]    [0012]FIG. 3 is a perspective, partially cut-away view of a second connector with a molded cap partially cut-away, for use with the rope lighting shown in FIG. 1.  
         [0013]    [0013]FIG. 4 is a schematic view illustrating an embodiment of a single strand of lights used in the rope lighting shown in FIG. 1.  
         [0014]    [0014]FIG. 5 is a schematic view illustrating the rope lighting apparatus shown in FIG. 1 with connection of several series strands of lights (shown in FIG. 4) in parallel for providing an illuminative ornamental effect. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0015]    With reference to the drawings, in which like parts have like identifiers, FIG. 1 illustrates in perspective view a flexible strand lighting apparatus  10  according to the present invention. The lighting apparatus  10  includes a power cord generally  12  and at least one elongate light strand generally  14 . The power cord  12  includes a plug  16  configured for matting engagement with a supply of high voltage, alternating current with a pair of electrical contact blades  18 ,  20  projecting from a distal end of the plug  16 . Each blade  18 ,  20  connects to a electrically conductive wire carried in a cord  22 . The parallel blade attachment plug  16  provides a connection to a conventional supply of electric current. The strain relief to the cord  22  is integral with the plug  16 , as is conventional. In the illustrated embodiment, the plug  16  includes a fuse recess  24  which is closed by a cover  26 . The fuse recess  24  receives a fuse  28  for providing current protection to the lighting apparatus  10 . The fuse  28  in the illustrated embodiment is maximum 5 amp. The wire in the cord  22  is copper or copper alloy, stranded wire, 18 AWG minimum, in which the hot and neutral wires are spaced-apart a minimum of 3 millimeters.  
         [0016]    An opposing distal end of the cord  22  terminates in a first connector  30 . The first connector  30  includes a strain relief  32  which provides a transition between the main body  34  of the first connector  30  and the cord  22 . A flange  36  projects radially outwardly from the main body  34  and defines a stop for a coupler  38  slidably received on the power cord  12 , as discussed below. A shank  40  projects forwardly of the flange  36 . The first connector  30  includes two sleeves  42 ,  44  which are electrically conductive and connected to the respective wires in the wire cord  22  for communicating with the parallel blades  18 ,  20 . A gasket  46  is received on the shank  40  and seats against the flange  36 . In the illustrated embodiment, the gasket  46  is molded of a low-density polyethylene foam to define an annular ring, with a 4 millimeter thickness, 1.3 centimeter inner diameter and 1.8 centimeter outer diameter. Preferably the gasket  46  is secured to the shank  40  by friction fit, such that the gasket stays in place during the disconnection of the connectors  30  and  58 , as discussed below.  
         [0017]    The coupler  38  is an open-ended body with an interior thread  37 . In the illustrated embodiment, the coupler  38  defines an octagonal exterior with faces that define finger grips  41  thereon. The coupler  38  has a first open end  43  sized for slidingly being received on the connector  30  and extending past the flange  36 . An opposing end  45  is of a smaller diameter to define a face that bears against the flange  36 .  
         [0018]    The light strand  14  includes an elongate transparent or translucent flexible tube or “rope”  50  that defines a rope-like flexible member. The rope  50  includes a plurality of spaced-apart bulbs  52  connected in series by electrical wires  54 ,  56 . The bulbs  52  in the illustrated embodiment are of a type rated 5 volts, 0.05 amps, and 0.25 watts, and are preferably non-shunted. The bulbs  52  are spaced a minimum of 2.5 centimeters between bases. The wires  54 ,  56  are carried in a U-shaped core  51  (see FIG. 3). A first distal end of the rope  50  terminates in a second connector  58  having a main portion  60  and a threaded portion  62 . The threaded portion  62  extends forwardly as an open-ended shroud  64  from an end wall of the main portion  60 . Disposed within the shroud  64  are a pair of spaced-apart pins  66 ,  68 . The outwardly distal end of the pins  66 ,  68  are flush with the distal end of the shroud  64 . The pins  66 ,  68  electrically connect to the wires  54 ,  56  in the rope  50 . The opposing distal end  76  of the light strand  14  terminates in another of the first connectors  30  which is as described above with respect to the power cord  12 .  
         [0019]    The light strand  14  is provided with an end cap  80  having a threaded exterior  82 . A flange  87  extends from a back of the end cap  80 . A cover  86  is sized for being received on the shank  40  of the connector  30  at the end of the light strand  14 . The end cap  80  is sized for receiving the cover  86  in overlying relation on the shank  40  for engaging the threaded coupler  38  received on the rope  50 . The end cap  80  thereby secures the cover  86  on the shank  40 , closing the distal end of the light strand  14 , while the cover  86  restricts moisture penetration to the electrical sleeves  42 ,  44 .  
         [0020]    [0020]FIG. 2 is a perspective, partially cut-away view of the first connector  30  which is molded in place to the wire cord  22  (or to a distal end of the rope  50  as also used with the light strand  14 ). The connector  30  encloses the sleeves  42 , 44  which are open-ended cylinders. The respective distal ends  90 ,  92  of the sleeves  42 ,  44  are open and extend to the end wall  45  of the shank  40 . An interior end of the sleeves  42 ,  44  are defined by clamps  96 , 98 . The clamps  96 , 98  are defined by wing-like flanges that fold over to bear against a respective wire  54 ,  56  from the rope  50 . The sleeves  42 ,  44  define holes  100 ,  102  between the clamp  96 , 98  and the distal ends  90 , 94 . The distal end of the respective wires  54 ,  56  are received through the holes  100 ,  102  and soldered in place prior to the folding flaps of the clamps  96 ,  98  over the wire.  
         [0021]    [0021]FIG. 3 is a perspective, partially cut-away view of the second connector  58  which defines a molded cap. The connector  58  is partially cut-away to illustrate features of the connector. The pins  66 ,  68  project forwardly from a wall  65 . The portion  64  of the threaded end  62  defines a shroud which encloses the pins  66 ,  68 . The interior diameter of the shroud is sized to receive the shank  40  of the connector  30 . An interior end  110 ,  112  of the pins  66 ,  68  have flat plates with each defining a hole  114 ,  116 . The wire  54 ,  56  carried in the rope  50  passes through the respective hole  114 ,  116 , wraps over itself, and is soldered to the plates  110 ,  112  of the pins  66 ,  68 . The wires  54 ,  56  in the cord  50  are carried in a core generally  51  having a U-shaped cross-section. The body of the connector  58  is preferably molded in place during manufacture, as discussed below.  
         [0022]    The sleeves  42 , 44  preferably taper narrowingly from the open ends  90 ,  92  to the opposing end at the holes  100 ,  102 , to facilitate gripping engagement with the pins  66 ,  68 , as discussed below. The sleeves  42 ,  44  in the illustrated embodiment taper in diameter from 2.8 millimeter to 2.4 millimeter, with a sleeve length of 15.7 millimeters. The pins  66 ,  68  in the illustrated embodiment are cylindrical, having diameters of 2.5 millimeter and a length of 20 millimeters from a leading tip to an opposing distal end of the plate which plate has a longitudinal length of 5 millimeters. The holes  100 ,  102  in the sleeves  42 ,  44  and the holes  114 ,  116  and the pins  66 ,  68  have 1.7 millimeter diameters for receiving the electrical wires. Preferably, the electrical wires are #18 AWG minimum, type SPT-2 marked “W” or “WA”. The holes receive the #18 AWG wire therethrough, which is soldered to the respective sleeve or pin. The sleeves  42 ,  44  are spaced-apart 6 millimeters center-to-center of the sleeves. The shank  40  extends 10 millimeters from the flange  36  and has a diameter of 13 millimeters. The flange  36  extends radially to define an overall diameter of 17.8 millimeters.  
         [0023]    [0023]FIG. 4 is a schematic view illustrating the light strand  14  shown in FIG. 1. The bulbs  52  are connected in series to the wires  54 ,  56 .  
         [0024]    [0024]FIG. 5 is a schematic view illustrating parallel connection of five series strings of the light strands  14  and one of the power cord  12  to provide a length of lights that mount in wet locations for a lighting ornamental effect.  
         [0025]    The Table 1 on the following page lists characteristics of several embodiments of the lighting apparatus  10 , in which in the rating V is volts, A is amperes, and W is watts. The length of the apparatus is shown in feet. Each lighting strand  14  has twenty-four bulbs  52 , spaced apart as indicated below in centimeters, with the total number of strands indicated. The input is 0.05 amps and 6 watts per twenty-four bulb series strand.  
                                 TABLE 1                           FLEXIBLE LIGHTING APPARATUS                    Bulb Spacing           Rating   length (ft)   (cm)   No. of Strands 14               120 V, 0.31 A,   12   3.1    5       37.2 W       120 V, 0.46 A,   18   2.8    8       55.2 W       120 V, 0.65 A,   25   2.8   11       78 W       120 V, 1.3 A,   50   2.8   22       156 W                  
 
         [0026]    With reference to FIG. 1, the power cord  12  is manufactured by cutting a wire cord  22  to length. The parallel blades  18 ,  20  connect conventionally to the wires in the cord  22 . The plug  16  is preferably conventionally injection molded to secure the blades  18 ,  20  within the plug and to connect the body of the plug to the wire cord  22 . The coupler  38  is received on the wire cord  22 . With reference to FIG. 2, the sleeves  42 ,  44  are engaged to the wires in the wire cord  22 . In the illustrated embodiment, the distal ends of the wires  54 ,  56  pass through the holes  100 ,  102  and are soldered to the sleeves  42 ,  44  to assure an electrical connection and a rigid physical connection between the sleeves and the wires. The flanges of the clamps  96 ,  98  are folded over onto the wire of the wire cord  22  to further secure the wire physically and in electrical communication with the sleeves  42 ,  44 . The engaged sleeves  42 ,  44  and wires are held, and the body of the connector  30  is molded around the sleeves and the cord  22 .  
         [0027]    With reference to FIG. 1, the light strand  14  is manufactured. The wires  54 ,  56  are encased with plastic to preferably define the U-shaped channel  51 . The bulbs  52  are soldered to the opposing wires  54 ,  56  in the channel  51  to provide the plurality of bulbs  52  connected in series. The assembly of the U-shaped channel  51  with the wires  54 ,  56  and the bulbs  52  is then encased in a larger plastic tube that is filled with a transparent, non-conductive plastic material to secure the bulbs  52  therein. The tube for the rope  50  is preferably QMFZ2 material manufactured by Georgia Gulf Chemicals &amp; Vinyls LLC, type SP-7107, tube type construction, with an 11 millimeter outer diameter, a 3.5 millimeter inner diameter, and a nominal 3.75 millimeter wall thickness. With reference to FIGS. 2 and 3, the connectors  30  and  58  are then molded conventionally to the distal ends of the rope  50  to enclose the sleeves  42 ,  44  and the pins  66 ,  68 , respectively.  
         [0028]    A plurality of the light strands  14  may then be used together with one of the power cords  12  to provide ornamental lighting effects in wet locations, such as exterior decks, landscaping, and the like. The light strands  14  are not intended to be cut during installation and use of the lighting apparatus  10 . With reference to FIG. 1, the gasket  46  is received on the shank  40  and seats against the flange  36 . The connector  30  of the power cord  12  matingly engages the connector  58  of a first one of the light strands  14 . The shank  40  is slidingly received in the shroud  64 , with the pins  66 ,  68  being slidingly received in the sleeves  42 ,  44 . The shroud  64  shields from inadvertent contact by the installer with the pins  66 ,  68  during assembly. The coupler  38  slides longitudinally pass the strain relief  32  and the main body  34  until stopped by the flange  36 . The coupler  38  is rotated using the finger grips  41  to engage the thread  37  with the threaded end  62  of the connector  58 . This secures the connector  30  of the power cord  12  to the connector  58  of the light strand  14 . The coupler  38  and the threaded end  62  accordingly engage the power cord  12  and the light strand  14 , while resisting moisture penetration to the electrical connection.  
         [0029]    Additional light strands  14  can be connected. The connector  58  of the additional strand  14  is matingly engaged to the connector  30  of the adjacent previous light strand  14 . This is accomplished by receiving the gasket  46  on the shank  40  and the shank slidingly received in the shroud  64  at the subsequent lighting strand  14 . The coupler  38  on the first light strand  14  is rotated to engage the threaded end  62  of the connector  58  on the subsequent light strand  14 . Additional light strands are similarly joined to the lighting assembly  10  by matingly engaging the connector  58  of a subsequent light strand to the connector  30  of the preceding light strand.  
         [0030]    The light strand  14  in the assembly  10  distal from the power card  12  is closed by sliding the cover  86  over the shank  40  of the final light strand  14 . The end cap  80  is then placed over the cover  86 . The open face of the cap  80  bears against the gasket  46  and the flange  36  of the final connector  30 . The coupler  38  on the final light strand  14  is rotated to engage the thread  37  with the thread  82  of the cap  80 . The flange  87  can be gripped in order to facilitate rotating the coupler  38  into matting engagement with the end cap  80 .  
         [0031]    The present invention accordingly provides an improved wet location flexible strand lighting apparatus in which a plurality of low wattage bulb light strings are selectively joined to provide an extended rope mountable in wet locations for providing ornamental effect. Thermoplastic “U” clips with screws (not illustrated) may be used to mount the lighting apparatus  10 , or nylon ties may be used. The lighting apparatus  10  is not intended to be cut-to-length during installation, whereby the electrical connections are secured and resist moisture penetration.  
         [0032]    While this invention has been described in detail with particular reference to the preferred embodiments thereof, the principals and modes of operation of the present invention have been described in the foregoing specification. The invention is not to be construed as limited to the particular forms disclosed because these are regarded as illustrative rather than restrictive. Moreover, modifications, variations, and changes may be made by those skilled in the art without departure from the spirit and scope of the invention as described by the following claims.