Abstract:
A grounding device comprising a ground lead and a support bushing wherein the ground lead and the support bushing comprise a unitary structure.

Description:
FIELD OF THE INVENTION  
         [0001]    This invention relates generally to grounding and more particularly to ground leads and support bushings, which create a grounding condition for an electrical apparatus.  
         BACKGROUND OF THE INVENTION  
         [0002]    Grounding is the intentional electrical connection to a reference-conducting plane, which generally consists of a specific array of interconnected electrical conductors referred to as the grounding conductor. Grounding provides a zero point for an electrical conductor system.  
           [0003]    Typically, grounding from a printed circuit board (“PCB”) to a grounding feature utilizes two separate components. These two separate components provide a grounding path from a PCB, or another electrical device, to a grounding feature. The ground lead and support bushing are individually manufactured and processed, and subsequently bolted or screwed together when inserted onto the grounding feature. The support bushing provides structural support for a housing, which contains the ground lead contacted to the PCB. The resulting combination of the support bushing and grounding lead contacted to the PCB is subsequently bolted to a grounding feature. In one example, automobiles serve as a grounding feature for a PCB that is contained within a housing. To create a grounding path between the vehicle and the housed PCB, a ground lead is press fit or soldered to the housed PCB. The other end of the ground lead has a ring which fits over the top of the support bushing, which is contained in a mounting pad of the housing. To connect the housing containing the PCB, a bolt goes through the mounting pad, and then passes through the ring of the ground lead and through the support bushing and into the vehicle. As a result, the ground lead and support bushing provides an electrical connection from the PCB to the grounding feature. An electrical current passes from the PCB into the ground lead, which is soldiered or press fit to the PCB. Then the electrical current passes to the support bushing, which is contacted to the grounding feature.  
           [0004]    In order for grounding to be complete, the bushing and ground lead must be in contact to create a completed grounding path. If there is no contact between the support bushing and the ground lead, the grounding path from a PCB, or another electrical device to a grounding feature will be broken. If there is a gap between the support bushing and the ground lead, a non-grounding condition will be created. In view of the foregoing, there is a need to have a permanent and reliable contact between a support bushing and a ground lead.  
         SUMMARY OF THE INVENTION  
         [0005]    The present invention provides apparatus and methods for constructing a support bushing and ground lead. In one embodiment, a ground lead and support bushing are constructed for insert molding by blanking and forming it from one piece of material to form a single integral and gaplessly continous piece.  
           [0006]    In another embodiment, the one-piece ground lead-support bushing provides a grounding path from a PCB, or another electrical device, to a grounding feature. One exemplary application for the one-piece ground lead-support bushing is in an automobile, where the ground lead-support bushing is assembled to the vehicle.  
           [0007]    Another aspect of an embodiment of the invention is that the one-piece ground lead-support bushings are manufactured and processed from the same sheet of material.  
           [0008]    In another embodiment, a carrier strip of material is blanked to provide a flat pattern of the one-piece ground lead-support bushing. Then the flat pattern is sent through a series of forming processes, which give the one-piece support bushing-grounding lead a shape that can be used in a variety of grounding applications. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    [0009]FIG. 1 is a perspective view of an exemplary unassembled ground lead and support bushing that is mounted to a grounding feature.  
         [0010]    [0010]FIG. 2 is a top isomeric view of a ground lead support bushing assembly in accordance with an embodiment of the present invention illustrating the unitary structure of the ground lead and support bushing.  
         [0011]    [0011]FIG. 3 is a bottom isometric view of a ground lead support bushing assembly in accordance with an embodiment of the present invention, illustrating the unitary structure of the ground lead and support bushing.  
         [0012]    [0012]FIG. 4 is a perspective view of an embodiment of a ground lead contacted to an exemplary printed circuit board, which is contained in an exemplary housing.  
         [0013]    [0013]FIG. 5 is a perspective view illustrating a bolt passing through a mounting pad and into a grounding feature.  
         [0014]    [0014]FIG. 6 is a perspective view of a flat pre-formed embodiment of the present invention, illustrating the unitary structure of the ground lead and support bushing.  
         [0015]    [0015]FIG. 7 is a perspective view of a plurality of the flat strip pre-formed embodiment of FIG. 6.  
         [0016]    [0016]FIG. 8 is perspective view of a ground lead support bushing assembly contained within an exemplary housing. 
     
    
     DETAILED DESCRIPTION  
       [0017]    While the present invention is susceptible of embodiments in varied forms, what is shown in the drawings will hereinafter be understood to be an embodiment of the present invention. The present disclosure is to be considered as setting forth an exemplification of the invention, which in no way is intended to limit the invention to the specific embodiment illustrated below. In referring to the drawings, like reference numerals indicate like parts throughout the several drawings.  
         [0018]    [0018]FIG. 1 shows an embodiment of a ground lead  20 , support bushing  40 , bolt  50  and grounding feature  60 . The ground lead  20  and support bushing  40  are secured together by any suitable means, such as by a bolt  50 . In this embodiment, bolt  50  is placed through the ground lead aperture  22 , through the support bushing aperture  42 , and then clamps the ground lead  20  to the support bushing  40  by attaching to the grounding feature  60 .  
         [0019]    [0019]FIG. 2 shows a preferred embodiment of a grounding device in accordance with the present embodiment. The view is a top isometric view illustrating an embodiment of a ground lead  20  and support bushing  40 , which are preferably blanked and formed from a single piece of material in this embodiment. The ground lead  20  and support bushing  40  do not require a bolt  50  to clamp the components together in this embodiment, since the ground lead  20  and support bushing  40  are blanked and formed from one piece of material. Ground lead  20  includes an arm  24  in this embodiment having a plurality of shoulders  26 , which total five in this embodiment. The five shoulders  26  are preferably bent, such as at substantially 90-degree angles in this embodiment. Ground lead  20  also has a ring  32  and tail  34  protruding from the back of the ring  32 . Tail  34  is slightly bent, on a downward plane in this embodiment, to provide balance to the ground lead  20  and support bushing  40 . The arm  24  also comprises a needle  28  and an eye  30  in this embodiment, which provides for press fit contact into a circuit board. The ring  32  includes an aperture  22 , which is substantially annular in the present embodiment. In addition, the support bushing  40  includes an aperture  42 , which is also generally annular. Apertures  22  and  42  are preferably sized large enough in this embodiment, so as to allow the bolt  50  to pass there through and secure the ground lead  20  and support bushing  40 , for example, to the exemplary grounding feature  60  in FIG. 1.  
         [0020]    [0020]FIG. 3 illustrates a bottom isometric view of the support bushing of FIG. 2. The support bushing  40  in the present embodiment has two substantially circular overlapping elements  44 , which create the aperture  42 . In the present embodiment, aperture  42  is aligned with, and shares, a substantially similar circumference as aperture  22 .  
         [0021]    [0021]FIG. 4 is a perspective view illustrating assembly of arm  24  into an exemplary housing  80  and connection to an exemplary printed circuit board  70  contained in housing  80 . The aforementioned assembly is then enclosed when the cover to the housing  86  is put into place. As discussed above, the arm  24  in this embodiment preferably includes needle  28  having an eye  30 , which provides for press fit contact to a printed circuit board  70 .  
         [0022]    [0022]FIG. 5 illustrates a perspective view of the bolt  50  of FIG. 1, which passes through an aperture  84  of a mounting pad  82  after the cover to the housing  86  has been put in place. The bolt  50  then passes through apertures  22  and  42 , respectively, and into a grounding feature  60 .  
         [0023]    [0023]FIG. 6 illustrates an exemplary embodiment of a substantially flat strip of a preferred embodiment of the present invention. In the forming process, ground lead  20  is formed when the five shoulders  26  of arm  24  of ground lead  20  are bent at substantially 90-degree angles, and when tail  34  is slightly bent in a downward direction. As the ground lead  20  is formed as described above, one or more, and preferably, two substantially rectangular members  44  are formed into the support bushing  40  of FIG. 2. The two substantially rectangular members  44  are formed underneath the ground lead  20  as substantially circular overlapping elements.  
         [0024]    [0024]FIG. 7 illustrates, generally, a blanked carrier strip  90  of the flat ground lead  20  and two substantially rectangular members  44 , which are formed into support bushing  40  of FIG. 2. In this embodiment, the carrier strip  90  has blank space  92 , which is blanked to form individual flat strips of FIG. 6, which can then be formed into their desired configuration. In this embodiment, the carrier strip  90  and blank space  90  have been blanked from a piece of material.  
         [0025]    [0025]FIG. 8 illustrates an exemplary housing  80  to be used with the apparatus and method of the present embodiment. The housing  80  in this embodiment is plastic and has a mounting pad  82  extending therefrom. The mounting pad  82  has an aperture  84 , which allows the bolt  50  of FIG. 1 to pass through, to provide connection for the housing  80  to, for example, the grounding feature  60  of FIG. 1. The support bushing  40  and ring  32  and tail  34  of FIG. 2 are integrated into the mounting pad  82 . The bolt then passes through aperture  84  of the mounting pad  82 , through the aperture  22  of the ring  32 , through the aperture  42  of the support bushing  40 , and into the grounding feature  60  of FIG. 1.  
         [0026]    For purposes of this invention, and without limitation, the grounding device and grounding feature described in the present embodiment is preferably comprised of stainless steel, aluminum, titanium, copper, or any other conductive material which exhibits appropriate grounding capacity. The housing in the aforementioned embodiments is comprised of a substantially non-conductive material, such as polyethylene, PBT, plastic or Teflon.  
         [0027]    The above description and the views and material depicted by the figures are for the purpose of illustration only and are not intended to be, and should not be construed as, limitations on the invention.  
         [0028]    Moreover, certain modifications or alterations may suggest themselves to those skilled in the art upon reading of this specification, all of which are intended to be within the spirit and scope of the present invention as defined in the attached claims.