Abstract:
An LED lamp assembly including an LED lamp and an LED insert having a body defining two coupler passages extending therethough from a top to a bottom thereof. Two conductive piercing couplers are engaged in one of the two coupler passages. The LED insert is engaged in an upper housing and the upper housing is coupled to a lower housing. The lower housing presents a wire receiving space structured and positioned to be aligned with the insulation piercing wire engaging portion of the two conductive piercing couplers when the upper housing is secured to the lower housing. The two leads of the LED lamp are positioned each in one of the two coupler passages in secure electrically conductive and mechanical contact with one of the spring contact portions of the two conductive piercing couplers.

Description:
RELATED APPLICATION 
       [0001]    This application is a continuation of application Ser. No. 13/240,628 filed Sep. 22, 2011, which is incorporated herein in its entirety by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates generally to light emitting diode lamps. More particularly, the present invention relates to light emitting diode lamps having housing and conductive structures to make consistent electrical contact with the conductor of a lamp wire. 
       BACKGROUND OF THE INVENTION 
       [0003]    Light emitting diode (LED) lamps provide a source of illumination for a variety of lighting applications including decorative lighting, automotive lighting, architectural lighting and other such applications. In particular, light emitting diodes are more commonly used in decorative Christmas light strings to reduce energy usage and provide pleasing color illumination. For those applications requiring that LED leads be coupled to an insulated conductor, such as in the context of decorative light strings such as those utilized for Christmas decoration, connecting the leads of conventional LED lead frames to wiring poses significant challenges. In some cases, in the prior art, leads are soldered directly to conductors to form a connection. In other circumstances, intermediate conductive structures such as wire terminals or mechanical connectors may be used to form an electrical connection. It can be difficult to make such connections. In particular, it can be difficult to make reliable connections that are consistently electrically and mechanically sound between the LED lead frame and the wiring. Poor connections can lead to lack of illumination, light failure, and can drive up the costs of manufacture and can potentially decrease the safety of the resulting lighting product. 
       SUMMARY OF THE INVENTION 
       [0004]    The present invention solves many of the above problems. An LED lamp assembly of the present invention generally includes an LED insert, an LED, a pair of conductive piercing couplers, an upper housing, a lower housing, an LED cover and two conductor wires. 
         [0005]    The LED insert generally houses the two conductive piercing couplers and supports the LED structure. The LED structure extends upwardly from the LED insert and the pair of leads of the LED extends downwardly into the LED insert and makes electrical contact with the upper portion of the conductive piercing couplers. The conductive piercing couplers extend downwardly and outwardly from the LED insert. 
         [0006]    The upper housing surrounds the LED insert and defines an upper opening through which the LED structure extends. The LED insert is receivable within the upper housing by being inserted from below into the cavity of the upper housing. When inserted into the upper housing, the conductive piercing couplers extend downwardly from the upper housing. 
         [0007]    The upper housing is coupleable to the lower housing, for example, by resilient snap-in type coupler structures. The lower housing includes wire receiving grooves therein through which the two conductor wire may pass. 
         [0008]    The cover includes a transparent or translucent structure through which light emitted by the LED passes. The cover may be colorless or act as a color filter while being transparent or translucent. The cover is received within the upper portion of the upper housing and may include a detent groove by which can be secured of the upper housing which has a mating structure to grasp the detent groove. The two conductor wire passes through the groove-receiving portion of the lower housing. The lower housing also has a piercing coupler receiving space defined therein. When the upper housing including the LED insert and conductive piercing couplers is assembled to the lower housing, the conductive piercing couplers pierce the insulation of the two conductor wire and each fork-like conductive piercing coupler engages one of the two parallel conductors of the wires. According to another embodiment of the invention, the conductive piercing couplers engage a single-conductor wire at locations separated from each other and the single conductor wire is severed therebetween by a severing structure thus creating a series connection to a single conductor wire. 
         [0009]    According to an example embodiment of the invention, the two conductive piercing couplers are similar in structure. The conductive piercing structure generally includes a fork portion, an insert engaging portion and a wire-receiving slot. The fork portion generally includes two piercing legs separated by a wire-receiving slot. The insert engaging portion generally includes one or more detents structured to engage alignment structures of the LED insert. The wire-receiving slot is resilient and extends outwardly away from the insert engaging portion. The spring-conductor portion is adapted to make contact with a lead of the LED structure. In another example embodiment the fork portion may be replaced by a spear portion piercing member that is adapted to pierce the insulation and to engage the conductor of the wire. 
         [0010]    The invention also includes a decorative light string including a plurality of LED lamp assemblies as described herein coupled to a length of wire conductor also having at least one plug or receptacle coupled to the conductors. Another embodiment of the invention includes a method of manufacturing a decorative light string including a plurality of LED lamp assemblies as discussed above and elsewhere in this application. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a perspective view of a LED lamp assembly and conductors according to an example embodiment of the invention; 
           [0012]      FIG. 2  is an exploded perspective view of a LED insert and conductive piercing couplers according to an embodiment of the invention; 
           [0013]      FIG. 3  is a perspective view of the assembled LED insert and conductive piercing couplers; 
           [0014]      FIG. 4  is a bottom view of the LED insert and conductive piercing couplers of  FIG. 3 ; 
           [0015]      FIG. 5  is an exploded perspective view of a LED insert and upper housing according to an embodiment of the invention; 
           [0016]      FIG. 6  is perspective view of an assembled LED insert and upper housing; 
           [0017]      FIG. 7  is an exploded perspective view of a LED and upper housing and a LED insert; 
           [0018]      FIG. 8  is a perspective view of an assembled LED insert and upper housing; 
           [0019]      FIG. 9  is a partial cutaway view of a LED insert and LED lamp as assembled; 
           [0020]      FIG. 10  is a sectional view of a LED insert and conductive piercing couplers according to an embodiment of the invention; 
           [0021]      FIG. 11  is an exploded perspective view of an upper housing, LED insert, LED and cover according to an embodiment of the invention; 
           [0022]      FIG. 12  is a partial cutaway view of an assembled cover, LED insert and upper housing according to an embodiment of the invention; 
           [0023]      FIG. 13  is an exploded perspective view of a lower housing and two conductor wire; 
           [0024]      FIG. 14  is assembled perspective view of the lower housing and two conductive wire; 
           [0025]      FIG. 15  is an exploded perspective view of the upper and lower housing according to an embodiment of the invention; 
           [0026]      FIG. 16  is a perspective view of a conductive piercing coupler according to an embodiment of the invention; 
           [0027]      FIG. 17  is a front elevational view of a conductive piercing coupler; 
           [0028]      FIG. 18  is a side elevational view of the conductive piercing coupler; 
           [0029]      FIG. 19  is a plan view of the conductive piercing coupler; 
           [0030]      FIG. 20  is a sectional view of the conductive piercing coupler and a LED insert; 
           [0031]      FIG. 21  is another sectional view of the conductive piercing coupler and the LED insert; 
           [0032]      FIG. 22  is phantom perspective view of the conductive piercing coupler within the LED insert; 
           [0033]      FIG. 23  is a plan view of the LED insert and conductive piercing coupler; 
           [0034]      FIG. 24  is a bottom view of the LED insert and conductive piercing coupler; 
           [0035]      FIG. 25  is a perspective view of a LED in contact with conductive piercing couplers with the LED insert not shown for clarity; 
           [0036]      FIG. 26  is a perspective phantom view of a lower housing; 
           [0037]      FIG. 27  is a bottom view of the lower housing; 
           [0038]      FIG. 28  is a bottom view of the lower housing and an LED insert inserted in the lower housing; and 
           [0039]      FIG. 29  is a sectional view of conductive piercing coupler engaged to a conductor of an insulated wire. 
       
    
    
     DETAILED DESCRIPTION 
       [0040]    Referring to  FIGS. 1-29 , LED lamp assembly  30  generally includes LED insert  32 , LED lamp  34 , conductive piercing couplers  36 , upper housing  38 , lower housing  40 , cover  42  and two conductor wire  44 . 
         [0041]    Referring to particularly to  FIGS. 2-4  and  FIGS. 20-24 , LED insert  32  includes body  46  generally including cylindrical portion  48  and base  50 . Body  46  further defines coupler passages  52  extending through body  46  from top  54  to bottom  56  thereof. According to the depicted embodiment, base  50  defines two curved walls  58  and flats  60 . Base  50  is shaped to act as an alignment structure when coupled with a complementary structure. LED insert  32  may be formed of a polymer such as polybutylene terephthalate (PBT), having Rockwell hardness, for example, of 121 R. According to an example embodiment, the invention LED insert  32  is formed of a more rigid material relative to upper housing  38  and lower housing  40  which are formed from more flexible material, for example, a polypropylene (PP) material, having a Rockwell hardness, for example, of 95 R, and as discussed further herein. However, it will be understood that materials of the same hardness may be used for both insert  32  and housings  38  and  40 , or materials having differing hardnesses, but not comprising PBT and PP, may also be used. In other words, though advantages in using materials of differing hardnesses are described herein, embodiments of the present invention are not limited to the specific example materials described herein. 
         [0042]    Referring particularly to  FIGS. 20-22 , coupler passages  52  define conductor-receiving portion  62  and lead-receiving portion  64 . 
         [0043]    Referring particularly to  FIGS. 20 and 21 , LED insert  32  presents upper positioning peg  66  and lower positioning peg  68  extending into coupler passages  52 . Coupler passages  52  also define L-shaped shoulder portion  70 . 
         [0044]    Referring particularly to  FIG. 23 , in one example embodiment conductor receiving portion  62  has a generally square cross section. 
         [0045]    LED insert  32  further presents top plane  72 , bottom plane  74  and plateau  76 . 
         [0046]    Referring to  FIGS. 16-19 , an example embodiment of conductive piercing couplers  36  is depicted. In the depicted embodiment, conductive piercing couplers  36  generally include insulation-piercing and conductor-engaging portion  77 . In this example embodiment, insulation piercing and conductor-engaging portion  77  is represented by fork portion  78 . The embodiment also includes, insert engaging portion  80  and wire-receiving slot  82 . Conductive piercing couplers  36  according to this example embodiment, are formed of a single piece of highly conductive metallic material such as copper, copper alloy or other such conductive metallic material. Conductive piercing couplers  36  may be formed, for example, by stamping and forming. 
         [0047]    Fork portion  78  generally includes two piercing legs  84  defining wire-receiving slot  86  therebetween. Each of piercing legs  84  presents beveled end  88 . Beveled ends  88  face each other creating funnel shaped entrance  90 . The width of wire-receiving slot  84  may be adjusted by those of ordinary skill in the art to properly accommodate the conductor of two conductor wire  44  or other wire having a single conductor or a plurality of conductors. Insulation piercing and conductor engaging portion  77  may also include a single piercing leg  84 . 
         [0048]    Insert engaging portion  80  of conductive piercing couplers  36  is generally formed of a thin planar sheet of conductive material and presents upper detent  92 , lower detent  94  and protruding shoulder  96 . Shoulder  96  is bounded by shoulder shelf  98 , shoulder overhang  100  and shoulder face  102 . 
         [0049]    Wire-receiving slot  82  of conductive piercing couplers  36  is generally parallel to insert engaging portion  80  and offset somewhat therefrom. Wire-receiving slot  82  generally presents hook portion  104 , offset portion  106  and angled portion  108 . The material of which conductive piercing couplers  36  is formed has sufficient resiliency that offset portion  106  is biased generally away from insert engaging portion  80 . Offset portion  106  may present rounded end  110 . 
         [0050]    Referring particularly to  FIGS. 5-8 ,  11  and  12 , in this example embodiment, upper housing  38  is a unitary molded structure which can be formed of non-conductive material such as a polymer. In particular, in one example embodiment, upper housing  38  may be formed of polypropylene (PP) or polyethylene (PE). Upper housing  38  may be molded, for example by injection molding. Upper housing  38  has a generally cylindrical structure having a generally cylindrical passageway centrally located therethrough. The exterior of upper housing  38  generally presents cylindrical portion  112 , beveled interrupted flange  114 , flats  116 , upper face  118  and lower face  120 . Beveled interrupted flange  114 , as depicted, includes two flange segments  122  offset approximately 180° from each other according to the depicted example embodiment. Other arrangements and numbers of flange segments  122  are also within the scope of the invention. Each of flange segments  122  presents perpendicular surface  124  and beveled surface  126 . Flange segments  122  also present chamfer  128  between perpendicular surface  124  and beveled surface  126 . 
         [0051]    Flats  116 , in this example embodiment, are located approximately 180° apart relative to cylindrical portion  112  and have faces that are generally parallel. 
         [0052]    Referring particularly to  FIG. 12 , the interior of upper housing  38 , generally defines lower portion  130  and upper portion  132 . Lower portion  130  is shaped so as to generally conform to base  50  of LED insert  32 . Upper portion  132  presents cylindrical walls  134  and annular ring  136 . Cylindrical walls  134  and annular ring  136  are dimensioned to receive cover  42  partially therein. Lower portion  130  and upper portion  132  meet and are divided by step  138 . 
         [0053]    Referring particularly to FIGS.  1  and  13 - 15 , lower housing  40  is a unitary structure which can be formed from a polymer such as polypropylene (PP) or polyethylene (PE). Lower housing  38  generally presents central base  140  and arcuate portions  142 . Arcuate portions  142  are located generally 180° apart and are substantially mirrored images of each other in the depicted embodiment. 
         [0054]    Central base  140  is generally flat and arcuate portions  142  extend upwardly therefrom. Lower housing  40  present a generally planar bottom surface  144 . Bottom surface  144  presents two arc shaped passages  146  extending therethrough. Upper surface  148  of central base  140  presents wire grooves  150  and rectangular recess  152  defined in plateau  154 . Rectangular recess  152  is generally centrally located in central base  140 . Wire grooves  150 , in the depicted example embodiment, are generally parallel and of equal size and shape. While two wire grooves are depicted a single wire groove  150  or multiple wire grooves  150  are also within the scope of the invention. Wire grooves  150  as depicted, generally are mirror images of each other. Rectangular recess  152  is centrally located and depressed into upper surface  148  of central base  140  to a greater degree than wire grooves  150 . 
         [0055]    Central base  140  is generally bounded by arcuate walls  156  which bound arch-shaped passages  146 . Arcuate portions  142  extend generally above upper surface  148  of central base  140 . Arcuate portions  142  present convex outer wall  158  and concave inner wall  160 . Concave inner wall  160  along with short walls  162  and arcuate walls  156  border on and define arc shaped passages  146 . Concave inner wall  160  also extends upwardly above upper surface  148  of central base  140 . Arcuate portions  142  also present upper wall  164 . Thus, arcuate portions  142  present inward facing openings  166  facing inwardly toward central base  140 . 
         [0056]    Referring to particularly to  FIGS. 11 ,  12  and  15 , in some embodiments, LED lamp assembly  30  may include cover  42 . Cover  42  comprises a hollow generally cylindrical structure. Cover  42  is closed at a top end thereof and, in the depicted embodiment, generally presents the appearance of a traditional mini Christmas light envelope. Cover  42  generally presents annular detent  168 , proximal a lower end thereof and conical top  170  proximal an upper end thereof. 
         [0057]    Cover  42  also may present knob  172  as depicted. Cover  42  is dimensioned to fit within upper portion  132  of upper housing  38 . Annular detent  168  is dimensioned to receive annular ring  136  therein in an interference fit. This description of cover  42  should not be considered limiting as cover  42  may take any desired shape that can be received within upper housing  38 . Further, the locations of annular detent  168  and annular ring  136  can be reversed. Cover  42  is formed of a translucent or transparent material and may be colorless or may be formed of a colored material to act as a color filter for light passing through it. 
         [0058]    In other embodiments, LED lamp assembly  30  may not include over  42 . For such embodiments, LED lamp  34  may extend above upper face  118 . 
         [0059]    Referring particularly to  FIG. 15 , two conductor wire  44  is generally conventional in design and may include stranded or solid conductive wire formed of, for example, copper. 
         [0060]    LED lamp  34  is a generally conventional LED lamp including leads  176  and lens  178 . LED lamp  174  includes an LED chip (not shown). LED leads  176  extend generally downwardly in a parallel fashion from lens  178  in this example embodiment. 
         [0061]    In operation, LED lamp assembly  30  is assembled as follows: 
         [0062]    Referring to  FIG. 2 , conductive piecing couplers  36  are inserted into LED insert  32  from the bottom of LED insert  32 . Upon being received in coupler passages  52 , upper positioning peg  66  and lower positioning peg  68  engage upper detent  92  and lower detent  94 . Shoulder  96  contacts L-shaped shoulder portion  70  thus preventing conductive piecing couplers  36  from being inserted to far into LED insert  32 . The engagement of upper positioning peg  66  with upper detent  92  and the engagement of lower positioning peg  68  with lower detent  94  secures conductive piecing couplers  36  within LED insert  32 . 
         [0063]    Referring particularly to  FIGS. 20 ,  23  and  24 , wire-receiving slot  82  is biased against lead receiving portion  64  of couple passage  52 . 
         [0064]    Referring particularly to  FIG. 5 , assembled LED insert  32  and conductive piecing couplers  36  are inserted into upper housing  38 . As described above, LED insert  32  in an embodiment comprises a material that is somewhat more rigid, or harder, than housing  38 . In an embodiment, LED insert  32  comprises a PBT material having a Rockwell hardness of 121 R, while upper housing  38  and lower housing  40  comprise a softer material, PP, having a Rockwell hardness of 95 R. The use of a relatively harder material, PBT, for LED insert  32 , as compared to upper housing  38 , may be advantageous for securing LED insert  32  with its piercing couplers  36  within upper housing  38 . When the fit between insert  32  and housing  38  is fairly tight, the PP material of housing  38  may compress when PBT insert  32  is inserted into housing  38 , thereby creating a tight compression and friction fit between the insert and the housing. Further, the harder PBT material of insert  32  ensures less movement of piercing couplers  36 , which as described further below assists with proper alignment with wires of a light set. 
         [0065]    Base  50  engages lower portion  130  of upper housing  38  as depicted in  FIG. 28 . Lower portion  130  of upper housing  38  is shaped to conform to base  50  of LED insert  32  and to receive flats  60  therein thus creating consistent orientation of LED insert  32  in relation to upper housing  38 . 
         [0066]    Referring particularly to  FIGS. 7-10 , leads  176  of LED lamp  174  are inserted into LED insert  32 . Leads  176  of LED lamp  174  pass into lead receiving portion  64  such that wire-receiving slot  82  makes electrical contact with leads  176  because of the bias of wire-receiving slot  82  toward the interior of lead receiving portion  164 . The engagement of leads  176  with wire-receiving slots  82  are depicted in  FIGS. 9 and 10 . 
         [0067]    As depicted in  FIGS. 11 and 12 , cover  42 , when used, is inserted into upper portion  132  of upper housing  38 . Because of the resilicency of upper housing  38 , and the relative stiffness of cover  42 , cover  42  can be inserted therein until annular detent  168  engages annular ring  136 , thus securing cover  42  within upper housing  38 . Light from LED lamp  174  passes through cover  42 . 
         [0068]    Referring to  FIGS. 1 and 15 , two conductor wire  44 , or a pair of single wires, is inserted into wire grooves  150  of lower housing  40 . Only a single conductor wire can be present in the case of a series wiring. More than two conductors may be present as well, for example in flashing or chasing light arrangements. 
         [0069]    Upper housing  38  and lower housing  40  are assembled by pressing or snapping them together. Beveled interrupted flanges  114  are received into inward facing openings  166  of arcuate portions  142 . Because of the resiliency of the PP material of lower housing  40 , lower housing  40  flexes to receive upper housing such that upper wall  164  of arcuate portions  142  engages perpendicular surface  124  of beveled interrupted flanges  114  thus securing upper housing  38  to lower housing  40 . 
         [0070]    At the same time, each wire of two conductor wire  44  is received into funnel shaped entrance  90  of wire-receiving slot  86  of fork portion  78  of conductive piercing couplers  36  as depicted in  FIG. 29 . Each of piercing legs  84  displaces and pierces the insulation of two conductor wire  44  and the conductors of two conductor wire  44  pass through funnel shaped entrance  90  into wire-receiving slot  86 . Wire-receiving slot  86  is sized to be somewhat smaller than the diameter of the conductors of two conductor wire  44 , thus indenting and deforming the conductors of two conductor wire  44  to create a tight reliable electrical connection. The use of a relatively hard material, such as PBT, for insert  32 , decreases deformation of insert  32 , thusly holding each of piercing legs  84  in a relatively constant position with respect to insert  32  as the insulation of wire  44  is pierced. Use of a softer insert  32  material, such as PP, would allow more deformation of insert  32 , and more movement of piecing legs  84  during the piercing process. The portion of piercing legs  84  that extends beyond two conductor wire  44  is received into rectangular recess  152  and may pierce lower housing  40 , which in an embodiment comprises a PP material, to some degree. A complete LED lamp assembly  30  is depicted in  FIG. 1 . 
         [0071]    The invention also includes a decorative string of lights including a plurality of LED lamp assemblies  30  assembled along the length of two conductor wire  44 . The invention also includes a method of assembling LED lamp assemblies  30  to two conductor wire  44  or to wire having a single conductor or more conductors. 
         [0072]    The invention may be embodied in other specific forms without departing from the spirit of the essential attributes thereof, therefore, the illustrated embodiments should be considered in all respects as illustrative and not restrictive, reference being made to the appended claims rather than to the forgoing description to indicate the scope of the invention.