Patent Publication Number: US-2006014421-A1

Title: Electrical connector apparatus and cover therefor

Description:
BACKGROUND OF THE INVENTION  
      1. Field of Invention  
      This invention relates to electrical connector apparatus and covers therefor.  
      2. Description of Related Art  
      Methods for terminating an electrical conductor abound. One common method involves the use of a screw terminal. Various types of screw terminals exist including barrier-type screw terminals that employ a row of screw terminals each of which is separated from an adjacent one by a barrier. The barriers tend to define a particular direction in which a wire or crimp connector may be installed on the screw terminal. Typically they permit a crimp connector or wire to be installed in only two directions, each about 180 degrees apart from the other. This can be limiting, especially where high current DC cables, for example are to be connected to the screw terminal.  
      Lead acid-type batteries typically have terminals which may include a conductive disk with a threaded stud projecting therefrom. The stud however is susceptible to being broken off due to excessive tightening torque, requiring replacement of the terminal or replacement of the battery. Typically this type of terminal is molded into a battery casing and is not easily removed.  
     SUMMARY OF THE INVENTION  
      The present invention provides a way of fastening electrical conductors, particularly relatively high current electrical conductors to a device having an internal printed circuit board, without placing strain on the printed circuit board, while providing an easy way of mounting a connector to the device. The invention need not be employed in this specific application and may be used generally anywhere a connector is required to connect one wire to another, especially on a device, where the two wires may be on opposite sides of a wall, barrier or bulkhead of the device.  
      In accordance with one aspect of the invention, there is provided an electrical connector apparatus. The electrical connector apparatus includes an electrically insulating base, and a conductor extending through the base. The conductor may include a first electrical terminal located on a first side of the base and a second electrical terminal located on a second side of the base. The apparatus may further include at least three spaced apart guides on the first side of the base, all of the spaced apart guides being adjacent the first electrical terminal and being operable to guide a wire terminated to the first electrical terminal to extend in any direction between two adjacent guides.  
      The first and second sides of the base may be on opposite sides of the base. The first electrical terminal may include a first threaded opening in the conductor. The second electrical terminal may include a second threaded opening in the conductor. The first and second threaded openings may be coterminous and form a threaded passageway through the conductor. The first and second threaded openings may be coaxial. The base may be molded about the conductor.  
      The base may include a mounting portion. The mounting portion may include a flat surface on the second side of the base. The flat surface may have threaded inserts disposed therein, for receiving fasteners for fastening the base to a device. The base may include a projection extending from the flat surface. The flat surface may have threaded inserts disposed therein and symmetrically about the projection. The flat surface may have an o-ring groove extending around the projection for receiving an o-ring for sealing the connector against a mounting surface.  
      The base may include a stage portion on the first side of the base. The spaced apart guides may be disposed about the stage portion. The base may include bridging surface portions extending between the guides, adjacent the stage portion. The base may include a first opening in the stage portion that extends to a cavity in the base. The base may further include a second opening in a distal end of the projection extending to the cavity. The conductor may include a rotation preventer operable to prevent rotation of the conductor relative to the base. The rotation preventer may include a flat surface on the conductor. The rotation preventer may be in the cavity.  
      The conductor may have first and second end portions with first and second distal surfaces respectively, and a length, measured between the first and second distal surfaces, that is slightly longer than the bore such that the first and second end portions project slightly beyond the distal ends of the projection and the stage portion.  
      The conductor may have first and second coterminous openings in the first and second distal surfaces respectively, forming a passageway through the conductor. The first and second coterminous openings and the passageway may be coaxial.  
      The first and second coterminous openings and the passageway may be threaded for receiving first and second bolts in the first and second openings respectively, for securing connectors on respective wires to the first and second electrical terminals respectively.  
      The guides may have respective flat planar distal end surfaces and the flat planar distal end surfaces may be disposed at a distance from the stage portion. The flat planar distal end surfaces may be coplanar. The guides may have respective threaded inserts in respective flat planar distal end surfaces, the threaded inserts being operable to receive fasteners for fastening a cover to the base.  
      The apparatus may further include a cover apparatus including a housing including joined rigid wall portions configured to extend about a perimeter and over a top of an electrical terminal, at least one of the wall portions having a conductor opening, the cover apparatus further including a conductor guard comprising a rigid guide wall extending from at least one of the wall portions, adjacent the conductor opening, to guard a wire terminated to the electrical terminal against small-radius bends near the electrical terminal.  
      In accordance with another aspect of the invention, there is provided a cover apparatus for covering an electrical terminal. The cover apparatus includes a housing including joined rigid wall portions configured to extend about a perimeter and over a top of an electrical terminal, at least one of the wall portions having a conductor opening. The cover apparatus further includes a conductor guard having a rigid guide wall extending from at least one of the wall portions, adjacent the conductor opening, to guard a wire terminated to the electrical terminal against small-radius bends near the electrical terminal.  
      The rigid guide wall may have an outwardly flared shape.  
      The wall portions and the rigid guide wall may be embodied in a unitary piece of insulating material.  
      The insulating material may include plastic.  
      At least one of the wall portions may have a landing formed therein, the landing having an opening, for receiving a fastener for securing the cover to the electrical terminal.  
      At least one of the wall portions may be curved and may be configured to extend over the top portion of the electrical terminal.  
      At least one of the wall portions may be curved and may be positioned opposite the wall portion having a conductor opening.  
      The wall portion extending over the top portion of the electrical terminal and the wall portion positioned opposite the wall portion having the conductor opening may be joined by an angled wall portion.  
      At least one of the wall portions may have a test probe opening operable to receive a test probe to permit contacting the test probe with the electrical terminal without requiring removal of the cover from the electrical terminal.  
      At least one of the wall portions may be curved and may be configured to extend over the top portion of the electrical terminal and may have a test probe opening operable to receive a test probe to permit contacting the test probe with the electrical terminal without requiring removal of the cover from the electrical terminal.  
      The wall portions configured to extend about a perimeter the electrical terminal may have edges that lie in a common plane. The rigid guide wall may be generally U-shaped and may have first and second leg portions having edges lying in the common plane. The rigid guide wall may include a curved joining portion joining the first and second leg portions, the curved joining portion having a radius of curvature becoming progressively larger progressively farther away from the housing.  
      Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      In drawings which illustrate embodiments of the invention,  
       FIG. 1  is a perspective view of an electrical connector apparatus according to a first embodiment of the invention;  
       FIG. 2  is a plan view of a first side of the electrical connector apparatus shown in  FIG. 1 ;  
       FIG. 3  is a top view of the electrical connector apparatus shown in  FIG. 1 ;  
       FIG. 4  is a side elevational view of a second side of the electrical connector apparatus shown in  FIG. 1 ;  
       FIG. 5  is a perspective view of a device on which the electrical connector apparatus shown in  FIG. 1  is to be installed;  
       FIG. 6  is a side view of the electrical connector apparatus shown in  FIG. 1 , shown mounted on a wall of the device shown in  FIG. 5 ;  
       FIG. 7  is a perspective view of a cover apparatus according to another embodiment of the invention;  
       FIG. 8  is a top view of the cover apparatus shown in  FIG. 7 ;  
       FIG. 9  is a first side view of the cover apparatus shown in  FIG. 7 ;  
       FIG. 10  is a bottom view of the cover apparatus shown in  FIG. 7 ;  
       FIG. 11  is a second side view of the cover apparatus shown in  FIG. 7 ;  
       FIG. 12  is a front view of the cover apparatus shown in  FIG. 7 ;  
       FIG. 13  is a rear view of the cover apparatus shown in  FIG. 7 .  
    
    
     DETAILED DESCRIPTION  
      Referring to  FIG. 1 , an electrical connector apparatus according to a first embodiment of the invention is shown generally at  10 . The apparatus includes an electrically insulating base  12 , a conductor  14  extending through the base and having a first electrical terminal  16  located on a first side  18  of the base. Referring to  FIG. 3 , the conductor  14  further includes a second electrical terminal  20  located on a second side  22  of the base  12 , opposite the first side  18 .  
      Referring back to  FIG. 1 , the apparatus  10  includes at least three spaced apart guides on the first side of the base  12  and in the embodiment shown there are four spaced apart guides identified as first, second, third and fourth guides  30 ,  32 ,  34 , and  36 . All of the spaced apart guides  30 ,  32 ,  34 ,  36  are adjacent the first electrical terminal  16  and are operable to guide a wire  108  terminated to the first electrical terminal  16  to extend in a sector  39  between two adjacent guides. Each of the guides  30 ,  32 ,  34  and  36  has an outer, distal surface  31 ,  33 ,  35  and  37 , and may be fitted with a respective threaded insert  51 ,  53 ,  55  and  57  in its respective distal surface. The guides confine the movement of the wire  108  connected to the first electrical terminal  16  to cause it to extend from the first electrical terminal in a direction defined between adjacent guides such as guides  34  and  36  as shown.  
      Referring to  FIG. 5 , the apparatus  10  may be mounted to an outside of a device  40  such as an inverter, for example, with fasteners  41  for holding the apparatus  10  being installed from an inside area  43  of the device, so that the fasteners cannot be seen or accessed from the outside of the device.  
      Referring to  FIGS. 1-4 , the base  12  further includes a mounting portion  50 , a projection  52 , and a raised stage portion  54  seen best in  FIGS. 1-3 . In the embodiment shown, the mounting portion  50  includes a wall  56  having a generally rectangular outer perimeter although the outer perimeter may be any suitable shape. The wall  56  defines the first and second opposite sides  18  and  22  of the base  12 .  
      On the first side  18  of the base  12 , the guides  30 ,  32 ,  34 ,  36  project from the wall  56  and the wall has generally coplanar bridging surface portions  62 ,  64 ,  66  and  68  that extend between successive guides. The raised stage portion  54  projects outwardly of the bridging surface portions  62 ,  64 ,  66  and  68  by about 1 mm and defines a relatively flat planar area  70  surrounded by the guides and bridging surface portions  62 ,  64 ,  66  and  68 . A first cylindrical opening  72  is formed in the flat planar area  70  and extends in a first direction to a cavity  71 . A second cylindrical opening  74  in a distal end  76  of the projection  52  extends in a second, opposite direction, into the cavity.  
      On the second side  22  of the base  12 , the wall  56  has a first flat mounting surface  58  having a central axis  60 . Threaded inserts  61 ,  63 ,  65  and  67  are installed symmetrically about the central axis  60  in the flat mounting surface  58 . The projection  52  has a cylindrical shape and extends outwardly from the first flat mounting surface  58  and is centered on the central axis  60 . The flat mounting surface  58  has an o-ring groove  59  therein for receiving an o-ring for sealing the connector against a mounting surface of a device such as device  40 .  
      In the embodiment shown, the conductor  14  is provided by a brass member that extends through the base  12 , from the first side  18  to the second side  22 . The conductor  14  has a section  78  having a rotation preventer, which in the embodiment shown includes at least one flat surface  79  that is received in the cavity  71  to hold it against rotation relative to the base  12 . The conductor  14  also has first and second end portions  80  and  82  extending in opposite directions from the section  78 . In the embodiment shown, the section  78  has a flat surface  79  to prevent relative rotation between the conductor  14  and the base  12 . In general, any method of preventing such relative rotation would work, including simple projections extending from the conductor  14  into the base  12  or flat surfaces on portions of the end portions  80  and  82  that are embedded within the base, for example. It will be appreciated that the cavity  71  and openings  72  and  74  need not be pre-formed in the base  12 , but rather may be formed by molding the base around the conductor  14 . Pre-forming of the cavity  71  and openings  72  and  74  may be required where the base is formed in two halves that are joined together about the conductor  14 , for example.  
      The first and second end portions  80  and  82  of the conductor  14  are dimensional to project slightly beyond a distal surface of the raised stage portion  54  and a distal surface of the projection  52 . The first and second end portions  80  and  82  have first and second generally flat distal surfaces  86  and  88  respectively. In the embodiment shown the first and second generally flat distal surfaces  86  and  88  have first and second coterminous, coaxial openings  90  and  92  respectively forming a passageway  94  formed along an axis of symmetry  96  of the conductor  14  coincident with the central axis  60 . Referring to  FIG. 6 , in the embodiment shown, the first and second openings  90  and  92  and passageway  94  are threaded for receiving first and second bolts  100  and  102  in the first and second openings  90  and  92  respectively, for securing crimp connectors  104  and  106 , to which respective external and internal wires  108  and  110  may be attached to the opposite ends of the conductor  14 . The first and second openings  90  and  92  and surrounding first and second generally flat distal surfaces  86  and  88  respectively act as the first and second electrical terminals  16  and  20  respectively.  
      Referring to  FIG. 5 , in use, a device  40  on which the apparatus  10  is to be used is configured to include a circular opening  120  having a diameter slightly larger than the diameter of the projection  52 . Additional openings such as opening  122  are formed in a wall  124  of the device  40  to facilitate receiving fasteners  41  such as screws therein to permit the fasteners  41  to engage with the threaded inserts  61 ,  63 ,  65  and  67  in the mounting surface  58 . The apparatus  10  is mounted to the device  40  such that the projection  52  projects inwardly into the device through the opening  120  and such that the fasteners  41  are inserted into the openings  122  from inside the device  40 . This ensures that the apparatus cannot be easily removed from the device  40  without opening it up. Referring to  FIG. 6 , when the apparatus  10  is mounted to the device  40 , the o-ring  71  seals the connector against the wall  124  of the device, thus making the device usable for both indoor and outdoor applications. A wire  110  internal to the device, from a circuit such as an inverter circuit inside the device may be connected to the second electrical terminal  20  by engagement of the second bolt  102  with a ring of a crimp connector  106  on the wire and by engagement of the second bolt  102  with the threads in the second opening  92 . The conductor  14  is thus electrically connected to the wire  110 .  
      The guides  30 ,  32 ,  34  and  36  project outwardly, generally normal to the surface of the wall  124  of the device  40 . An external wire  108 , such as from a battery, for example, may be connected to the first electrical terminal  16  by engagement of the first bolt  100  with a ring of a first crimp connector  104  on the external wire  108  and engaging the threads on the first bolt with the threads in the first opening  90 . The external wire  108  is thus electrically connected to the first electrical terminal  16  and is connected to the first terminal through the conductor  14 . As the first bolt  100  is tightened in the first opening  90 , the high torque forces involved as the bolt is tightened may have a tendency to rotate the crimp connector  104  about the central axis  60 . The guides adjacent the crimp connector  104 , only one of which is shown at  36  in  FIG. 6 , limit the range of rotation of the crimp connector to only a small sector, thus permitting the external wire  108  to extend from the connector generally radially, in a generally well-defined direction. The raised stage portion  54  and protruding generally flat distal surface  86  of the conductor  14  ensure a good, maximum surface area contact between the crimp connector  104  and the protruding generally flat distal surface  86  and provide clearance between the crimp connector  104  and the bridging surface portions  62 ,  64 ,  66  and  68  to avoid deforming the crimp connector  104  when the first bolt  100  is fully tightened in the first opening  90 . A similar advantage is achieved at the second electrical terminal  20  due to the second end portion  82  of the conductor  14  projecting slightly beyond the end of the projection  52 .  
      Additional wires may be connected to the first electrical terminal  16  by overlaying crimp connectors connected to respective such wires so that respective rings of the crimp connectors are axially aligned to receive the first bolt  100 , and by securing the bolt with the crimp connectors thereon to the first opening  90 . Respective wires may be arranged to extend between respective pairs of guides  30 ,  32 ,  34  and  36  such that each wire extends generally radially from the opening in a sector determined by the spacing of the respective pair of guides and the width (diameter) of the crimp portion of the respective crimp connector.  
      Referring to  FIG. 7 , in accordance with another aspect of the invention, there is provided a cover apparatus  150 , in accordance with one embodiment of the invention, for covering an electrical connector apparatus such as the one described above. In the embodiment shown the cover apparatus  150  includes a main housing  151  comprised of first  152 , second  154 , third  156 , fourth  158 , fifth  160  and sixth  162  joined rigid wall portions configured to extend about the perimeter and top of the base of the electrical connector apparatus  10  described above. The first, second, third and fourth wall portions  152 ,  154 ,  156  and  158  have respective edges  172 ,  174 ,  176  and  178  each having an edge surface lying in a common plane. In use, when the cover apparatus  150  is installed on the connector apparatus  10 , the common plane would be coincident with a mounting surface on a wall such as wall  124  the device  40 , or spaced apart slightly therefrom.  
      At least one of the wall portions has a conductor opening  180  and in the embodiment shown, the conductor opening is in the third wall portion  156 . The cover apparatus  150  further includes a conductor guard  190  comprising a rigid guide wall  192  extending outwardly of the third wall portion  156 , adjacent the conductor opening  180 , to guard a wire terminated to the connector apparatus  10  described above against small-radius bends near the connector apparatus.  
      In the embodiment shown, the wall portions  152 ,  154 ,  156 ,  158 ,  160  and  162  and the rigid guide wall  192  are embodied in a unitary piece of electrically insulating material such as hard plastic.  
      The first and second side wall portions  152  and  154  are generally flat. The third wall portion  156  is generally flat with the rigid guide wall  192  extending therefrom. The fourth wall portion  158 , disposed opposite the third wall portion  156  is convexly curved. Thus, the wall portion on a side of the cover opposite to the side from which the rigid guide wall extends is convexly curved.  
      The sixth wall portion  162  extending over the top portion of the electrical terminal is curved and joins the first, second and third side wall portions  152 ,  154  and  156 . The fifth wall portion  160  extends between the fourth wall portion  158  and the fifth wall portion  160  and joins each of these wall portions such that it extends at an angle relative to the common plane in which the edges  172 ,  174 ,  176  and  178  lie.  
      At least one of the wall portions has a test probe opening  179  operable to receive a test probe to permit the test probe to contact the electrical terminal without requiring removal of the cover therefrom. In the embodiment shown, the test probe opening  179  is in the sixth wall portion  162 .  
      In the embodiment shown, the rigid guide wall  192  is generally U-shaped having first and second leg portions  194  and  196  and a curved joining portion  197  joining the first and second leg portions  194  and  196 . The first and second leg portions  194  and  196  are terminated in respective coplanar edges  198  and  200  that are coplanar with the edges  172 ,  174 ,  176 , and  178  of the main housing  151 . The first and second leg portions  194  and  196  also have distal portions  202  and  204  terminated in a single continuous distal edge  206  that defines an access opening  208  through which a wire connected to the connector apparatus  10  housed by the cover apparatus  150  may extend. The rigid guide wall  192  is configured such that the first and second leg portions  194  and  196  become progressively longer, progressively farther away from the third wall portion  156 , and such that the radius of curvature of the joining portion  197  becomes progressively larger such that the access opening  208  is slightly larger than the conductor opening  180  in the third wall portion  156 . The rigid guide wall  192  thus has an outwardly flared shape. This reduces any chance of cutting insulation on a wire extending into the housing due to rubbing of the insulation on the distal edge  206 .  
      In the embodiment shown, the first and second wall portions  152  and  154  have first and second landings  220  and  222  formed at right angles therein, to align with corresponding fastener openings in an electrical connector with which the cover apparatus  150  is to be used. In the embodiment shown, the first and second landings  220  and  222  align with corresponding threaded inserts  51 ,  53 ,  55  and  57  in the guides  30 ,  32 ,  34  and  36  of the connector apparatus  10  described above. The landings  220  and  222  have first and second openings  224  and  226  respectively therein for receiving a fastener (not shown) for fastening the cover apparatus  150  to the connector apparatus  10 . The sixth wall portion  162  has first and second recessed areas  228  and  230  adjacent the first and second landings  220  and  222  respectively, facilitating application of a tool such as a screw driver to fasteners received in the first and second openings  224  and  226 . In the embodiment shown, the threaded inserts  51 ,  53 ,  55  and  57  in the guides  30 ,  32 ,  34  and  36  are arranged symmetrically at a common distance from the central axis  60 . Similarly, the first and second landings  220  and  222  and first and second openings  224  and  226  are arranged symmetrically about an axis of the cover at distances similar to those of the threaded inserts. Consequently, the cover apparatus  150  may be placed on the connector apparatus  10  at one of four orientations, allowing the cover apparatus to permit a wire connected to the connector apparatus to extend in any of four directions from the connector apparatus. Similar symmetrical connector and cover arrangements could be made with other connectors having three or more guides and correspondingly shaped covers.  
      Different cover apparatuses of the type described may be colored red and black, for example and used on positive and negative terminals on the device  40 , for example.  
      While specific embodiments of the invention have been described and illustrated, such embodiments should be considered illustrative of the invention only and not as limiting the invention as construed in accordance with the accompanying claims.