Patent Publication Number: US-9887469-B1

Title: Insulation displacement wire connector with an exterior wire guide

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
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     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
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     REFERENCE TO A MICROFICHE APPENDIX 
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     BACKGROUND OF THE INVENTION 
     In some field applications branch connections need to be formed to a main electrical line without disrupting or severing the main electrical line. This is particularly true with tracer wires as one oftentimes needs to attach a branch wire to a main wire to form an electrical connection therebetween without cutting the main wire. One of the difficulties in forming a mechanical wire connection between a main tracer wire and a branch tracer wire is that one needs to maintain the integrity of the wire connection during the subsequent handling of the wire connector. The handling of the wire connector prior to or during the burial of the branch wire may accidently pull the branch wire free from the main wire, which results in an open circuit. One of the types of connectors commonly used to form such mechanical electrical connections between insulation covered tracer wires and the like are insulation displacement connectors since they can simultaneously form an electrical connection between wires even though the insulation is not stripped from the wires. 
     The insulation displacement connectors, which are well known in the art, typically comprise a pair of cantilevered spaced apart blade members each having internal edges for penetrating through an outer insulation cover on a wire to bring the edges into electrical contact with the electrical wire. The insulation displacement connectors, which are often referred to as IDC connectors allow one to quickly form an electrical connection between insulation covered electrical wire and the blade members within the IDC connector without having to manually remove the insulation covering from the wire. The spacing of the blunt edges of the blade from each other are sized so that when an electrical wire with an insulation covering is forced between the blunt edges on the blades the blunt edges penetrate through the softer insulation covering to bring the blunt edge of the blades into electrical contact with the harder metal electrical wire. Typically, the spacing between the blades is wider at the top to facilitate insertion of the wire between the blades. 
     Examples of insulation displacement connectors can be found in the following U.S. patents. 
     U.S. Pat. No. 4,682,835, shows an IDC connector where the thickness of upper part of the blade is at a reduced dimensions compared to the lower section of the blade. 
     U.S. Pat. No. 4,826,449 shows a pair of blades that includes projections on the back edge of the blades to stiffen the blades and increase resistance to outward deformation of the blades during wire insertion at low temperatures. 
     U.S. Pat. No. 4,002,391 shows an IDC connector with a set of offset swages in the blades to cut the insulation from different sides as the wire is inserted between the blades. 
     U.S. Pat. No. 3,636,500 shows an IDC connector with that cut a square notch in the insulation through sharp corner edges on the blades that remain in place until engaged by the conducting wire. 
     U.S. Pat. No. 3,521,221 shows tapered edges on the blade so more than one size electrical wire can be inserted into electrical engagement with the blades. 
     U.S. Pat. No. 7,934,941 shows an IDC connector, which has a pair of covers that are folded together to clamp the electrical wire therebetween. 
     U.S. Pat. No. 7,458,840 shows a set of parallel blades that are connected together with different slot spacing between each of the blades. In one pair of blades there is a narrow slot located at the slot entrance of one pair of blades and a wide slot located at the bottom of the blades at the other pair of blades there is a wide slot located at the slot entrance and a narrow slot at the bottom of the slot. 
     U.S. publication 2016/0218444 shows an insulation displacement connector with dual blades for engaging the wires therein. 
     U.S. publication 2015/0288078 shows another example insulation displacement connector with levers for bringing the blades in the wire connector into engagement with the wires therein. 
     The examples of IDC connectors listed above reveal that a variety of insulation displacement connectors are available that allow one to form an electrical connection through an insulation covered wire without having to strip the insulation covering from the wire. Typically, one of the advantages of IDC connectors is that they can be used to connect a main wire line to a branch wire line without having to cut the main wire line, which makes them useful in applications such as tracer wire applications where a series of branch wire lines may be connected to a main wire line in order to provide an underground wire network that can later be located using above ground equipment. Typically, the tracer wires are placed along an underground pipeline when the pipeline is buried so that one can later detect the location of the underground pipeline with above ground equipment through the sensing the presence of the underground tracer wires. In most cases the main underground pipeline includes branch underground pipelines, which also need to be identified through placement of tracer wires along the branch lines. To identify both the main pipeline and the branch pipeline a branch tracer wire, which extends along a branch pipeline is connected to the main tracer wire that extends along the main pipeline, preferably without severing the tracer wire that extends along the main pipeline. The simultaneous formation of the electrical connection and the removal of the insulation on the branch line wire and the main line wire, which occurs in one step is a time saving field benefit. However, unless care is taken in handling the IDC connector the electrical connection formed therein may be disrupted during the subsequent handling of the IDC connector thus spoiling the electrical connection between the branch wire and the main wire. This is particularly true in cases where the IDC connector joining the main wire and the branch wire are buried underground since the forces generated on the wires during the process of burying the connector in the soil may unknowingly disrupt the electrical connection between the branch wire and the main wire. If the broken electrical connection is noticed, one must remove the connector from the soil and reform the electrical connection therein and then rebury the connector in the soil. On the other hand, if the broken electrical wire connection is not noticed a future operator may not be able to detect or locate the underground branch pipeline, which may lead to disastrous results since an operator digging in the area may accidently rupture the branch pipeline, for example with a backhoe shovel or the like, which can cause an explosion or at the least cause an environmental disastrous as the contents of the branch pipeline are released into the environment. 
     SUMMARY OF THE INVENTION 
     A wire connector for connecting and maintaining a branch wire connected to a main uncut wire during handling of the wire connector and without cutting the main wire by laterally inserting the main uncut wire into a laterally open wire port in a piston sleeve and extending a cut end of a branch wire through an offset wire guide on the exterior of the wire connector and then reversing the branch wire direction to form a slack loop in the branch wire as the direction of the branch wire is reversed before inserting the end of the branch wire into a further wire port in the piston sleeve with the piston sleeve carrying a slideable piston having a set of insulation displacement blades that remove insulation from both the branch wire and the main wire while forming an electrical connection therebetween. The piston, which is isolated on one side of a lid, may be forced into the piston sleeve, either through hand pressure or use of pliers since a compression surface on the lid and a compression surface on the piston are in axial alignment with each other. Once the connection of the main wire to the branch wire has been formed the piston and piston sleeve with the wire connection therein can be quickly encapsulated in a sealant by pivoting the lid with the insulation displacement connector into a sealant-containing chamber of a housing through a living hinge that connects the housing to the lid. The lid may then be secured to the housing through a set of latches. While the main line, which is uncut, exits laterally from the housing the branch line connected thereto also exits laterally and follows a circuitous path to form a slack loop therein as the branch wire loops back on itself through the tubular guide, which is located on the outside of the housing. The introduction of a slack loop on the outside of the wire connector increases the resistance to accidental disruption of the connection of the branch line to the main line during the handling of the wire connector since the branch wire outside the connector is now capable of movement with respect to the wire connector without disrupting the wire connections therein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective open view of a wire connector with a lid mounted insulation displacement connector for attachment of a branch wire to a main wire without having to cut the main wire; 
         FIG. 2  is an exploded view of the lid mounted insulation displacement connector of  FIG. 1 ; 
         FIG. 3  shows the lid mounted insulation displacement connector of  FIG. 1  with an uncut main wire and a branch wire threaded through a wire guide on the lid; 
         FIG. 3A  shows an isolated view of a set of flexible flaps on the wire connector housing that allow lateral insertion of a wire therein; 
         FIG. 4  shows the lid-mounted insulation displacement of connector of  FIG. 3  supporting the uncut main wire and the branch wire with the branch wire having a slack looped formed by looping the branch wire into the lid mounted insulation displacement connector; 
         FIG. 5  shows the lid mounted insulation displacement connector of  FIG. 4  in the wire engaging position with the branch wire having a slack looped formed by looping the branch wire into the lid mounted insulation displacement connector; 
         FIG. 6  is a perspective view of the tubular wire guide on the outside of the lid mounted insulation displacement connector; 
         FIG. 7  is a top view of the tubular wire guide on the outside of the lid mounted insulation displacement connector; 
         FIG. 8  is a perspective view of outside of the wire connector in a closed condition. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIG. 1  is a perspective open view of a wire connector  10  comprising a lid mounted insulation displacement connector  10   a  for use in on-the-go attachment of a branch electrical wire to a main electrical wire without having to cut the main wire to form the electrical junction therebetween. The wire connector  10  includes a living hinge  17  connecting a lid  18 , which carries the insulation displacement connector  10   a , to a housing  10   b  having a chamber  11   a  therein for encapsulating the lid mounted insulation displacement connector  10   a . Located at one end of housing  10   b  is a planar lip  12  and on other end is a planar lip  13  with lip  12  including a first slot or lip latch  12   a  and a second slot or lip latch  12   b  with the lip latches located in a side-by-side position. On the other end of housing  10   b  planar lip  13  includes a first slot or lip latch  13   a  and a second slot or lip latch  13   b , which are also located in a side-by-side position. The lid  18 , which connects to lip  13  through a living hinge  17 , includes an offset tubular wire guide  16  that extends across the outside surface  18   a  of lid  18 . In this example the interior circumferential surfaces of lid  18  can be mated to the lips  12  and  13  on of the housing  10   b  through pivoting the lid  18  about the living hinge  17 . Once pivoted the lid  18  can then be latched to the housing  10   b  to thereby protect the insulation displacement connector  10   a  from the environment. 
     Mounted on the inside  18   b  of lid  18  is the insulation displaced connector  10   a  that includes a piston sleeve  20  with a slideable piston  21  therein. In this example the piston  21  has a top surface  21  and sidewalls  21   c  that slidingly fit within mating internal sidewalls  20   b  of piston sleeve  20  to allow the piston  21  to slide downward within piston sleeve  20  when axial pressure is applied to piston top surface  21   a  and to outside surface  18   a  of lid  18 . Once the piston is depressed to form an electrical connection therein a protrusion  21   d  on piston  21  locks with the edge of slot  20   c  in piston sleeve  20  to hold the insulation displacement connector  10   a  in a closed or locked condition to ensure that the blades within the connector remain in contact with the wires therein.  FIGS. 1-3  show that one end of lid  18  includes a first latch hook  19   a  for engagement with lip latch  12   a  and a second latch hook  19   b  for engagement with lip latch  12   b . The other end of lid  18  includes a third latch hook  20   a  for engagement with lip latch  13   a  and a fourth latch hook  20   b  (see  FIG. 8 ) for engagement with the lip latch  13   b . Located on the exterior surface of lid  18  is a tubular wire guide  16  that extends crosswise across the lid  18  and is laterally offset from a wire port  40  in piston sleeve  21 . 
       FIG. 2  is an exploded view of the lid mounted insulation displacement connector  10   a  of  FIG. 1  showing the axially slideable piston  21  that carries a metal insulation displacement blade  25  that can form an electrical connection as the insulation is removed from a wire. As blade  25  is activated by forcing piston  21  downward a first wire enters the slot  25   a  and a second wire second wire enters the slot  25   b . The displacement of the wires into the slots causes the edges of the blade  25  proximate the slot to remove the insulation from the wires and at the same time form an electrical connection between the wires through the electrical conducting blade  25 . Examples of such blades can be found in applicants pending application U.S. publication 2016/0218444, which is hereby incorporated by reference. 
       FIG. 3  shows the lid mounted insulation displacement connector  10   a , which is centrally located as well as centrally isolated on an inside surface  18   b  of lid  18 . An uncut main insulation covered electrical wire  30  is shown located in a laterally open wire port  41  that is laterally open at the top to allow insertion of an uncut wire therein but includes a lower lip  41   a  to laterally retain wire  30  therein until the electrical connection is formed therein. 
       FIG. 3  also shows a branch insulation covered electrical wire  31  with a cut end  31   a  with the branch wire  31  extending through an opening  16   a  in a tubular wire guide  16 , which is integrally formed on the exterior of lid  18 . As can be seen the uncut main wire  30  has been laterally inserted into lateral wire port  41  and into a position where electrical contact can be made through engagement with blade  25  while the branch wire  31  remains separate from the insulation displacement connector  10   a.    
       FIG. 3  shows a set of flap members  11   b ,  11   c ,  11   d  and  11   e , which comprise a set of laterally enterable flexible wire ports, that allow the branch wire and the main wire to extend through the circumferential sidewall  15  of the housing  10   b  when the lid  18  carrying the insulation displacement connector  10   a  is folded onto housing  10   b .  FIG. 3A  shows an isolated detail of housing  10   b  revealing that cantilever flap member  11   b  includes a set of cantileverly mounted flaps  35 ,  36 ,  37  and  38  that form a laterally enterable wire entry port  11   b  in housing  10   b , which allows wires carried by the insulation displacement connector  10   a  to extend through the sidewall  15  of the housing  10   b  when the lid  18  is brought into engagement with the housing  10   b . The outermost edges of cantilever mounted flaps  35 ,  36 ,  37  and  38  form a living hinge with the housing  10   b  while the inner edges  36   a ,  37   a  and  38   a  indicate separation edges where each of the cantilevered flaps can flex apart or separate as one inserts a wire between the flaps  35 ,  36 ,  37  and  38 . While only one of the sets of flap members  11   b  is described herein the flap members  11   c ,  11   d  and  11   e  are identical. The sealing action of the flap members  11   b  and  11   c  is illustrated in  FIG. 8 , which shows wire  30  extending through flat  11   b  and wire  31  extending through flap  11   c . Although not shown the flaps  11   d  and  11   e  operate in an identical manner in relation to sealing around the wires extending outward from the opposite side of the insulation displacement connector  10   a.    
       FIG. 4  shows the lid-mounted insulation displacement connector  10   a  of  FIG. 3  with the uncut main wire  30  in lateral wire port  41 . In order to generate slack loop  31   b  the wire branch wire  31  extends through tubular guide  16  and is looped backward 180 degrees until it extends through the wire port  40 . The tubular guide  16  allows one to form a slack loop  31   b  in branch wire  31  that can accommodate accidental wire displacement without disrupting the electrical connection in the wire connector.  FIG. 3  and  FIG. 4  show piston  21  in the up position, which enables an operator to insert end  31   a  of branch wire  31  into port  40  and to laterally place main wire  30  in wire port  41 . A feature of the invention is that the main wire  30  remains in an uncut condition while the branch wire  31  has been cut with a cut end  31   a  extended through an opening  16   a  in tubular guide  16 , which is laterally offset from the wire port  40 . In addition, in this example the opening  16   a  in tubular guide  16  is larger than the wire  31  so that an operator can use the inherent stiffness of wire  31  to thread the wire  31  through the tubular guide  16  thus avoiding the need for a wire-pulling device. Even though the tubular wire guide  16  has a larger diameter than the branch wire  31  the tubular wire guide maintains the slack loop  31   b  in wire  31  even though the size of the slack loop  31   b  may change in response to burial of the wire connector. 
       FIG. 5  shows that the piston  21  carrying the insulation displacement blades  25  ( FIG. 2 ) has been forced into the piston sleeve  20  through the application of a force F on the lid outer surface  18   a  and the piston top surface  21   a . A feature of the invention is that the placement of the insulation displacement connector  10   a  on the lid  18  is such that an axial compression force F can be conviently applied to lid surface  18   a  and the piston top surface  21   a  to bring the piston  21  into the piston sleeve  20 . Methods of applying force may be through jaws of a plier or the like since the tubular guide  16  is laterally offset from a compression axis of the insulation displacement connector  10   a  and thus does not interfere with exerting compression forces directly on the insulation displacement connector and the lid supporting the insulation displacement connector  10 . In this example the slack loop  31   b  is located on the outside of the housing so the branch wire  30  extends through the flap members in the housing. 
       FIG. 6  is a perspective view of the back side of the wire connector  10  showing the tubular wire guide  16  located on the outside of the lid  18  and extending across the lid  18 . Note, the wire  31  loops back 180 degrees to form a slack loop  31   b  before the wire  31  enters the wire port  40  (see  FIG. 5 ) in the lid mounted insulation displacement connector  10   a.    
       FIG. 7  is a top view of the lid mounted insulation displacement connector  10   a  showing that the uncut wire  30  extends crosswise through the insulation displacement connector  10   a  and the cut branch wire also extends through insulation displacement connector  10   a , however wire  31  forms a slack loop  31   b , which provides slack to the wire to resist dislodging the connection between the branch wire and the main wire. That is, the slack loop  31   b  provides a buffer in the event an external force is applied to the cut wire  31 . While the slack loop  31   b  absorbs wire displacement a further feature of the invention is that once the slack loop  31   b  in wire  31  is taken up the wire creates frictional resistance to further displacement through the corner engagement of the wire  31  with the edge of the lid  18  and the corner engagement of wire  31  with an edge of the tubular guide  16 . This feature further reduces any pulling strain on the connection between the wire  31  and the blades  25  thus further enhancing the resistance of the wire connector to failure due to an electrical connection being disrupted during handling or burial of the wire connector. 
     In the example shown in  FIG. 7  a waterproof sealant  50  is located in the chamber in housing  10   b  to enable the encapsulation of the insulation displacement wire connector  10   a  and the wires therein in order to protect the wire connections from the environment. 
       FIG. 8  is a perspective view of the wire connector  10  showing the latch hooks  20   a  and  20   b  in engagement with lip  13  and the latch hooks  19   a  and  19   b  in engagement with lip  12  to hold the lid  18  on the housing  10   b  thereby protecting the contents of the wire connector from a hostile environment while allowing the wires therein to protrude through a sidewall of the housing. A further feature is that the four corner engagement of hooks  19   a ,  19   b ,  20   a  and  20   b  ensures that the lid  18  and housing  11   a  remain attached during handling, while the living hinge provides for ease in lining up the latches and the latch hooks when the lid  18  is folded onto the housing  10   b.