Patent Publication Number: US-6702605-B2

Title: Z-shaped insulation displacement contact

Description:
This invention relates to an insulation displacement contact. 
     Australian Patent specification 90449/98 describes an electrical power outlet having insulation displacement contacts for connecting insulated wire thereto. More particularly, there is described an insulation displacement contact formed from a conductive element having an aperture therein, opposed portions of the edge of the aperture defining opposed contact portions which extend inwardly towards each other and which have inner opposed contact edges which define a channel therebetween, whereby a wire having a conductor surrounded by insulation may be introduced into the channel and pressed into the channel to cut the insulation of the wire and make electrical contact between the contact edges and the conductor. 
     In the arrangement as last-described, a carrier may be provided, slidable with respect to the conductive element and having an opening into which the wire may be introduced such that the wire extends into the opening and also through the aperture at a portion of the aperture spaced from the channel, the wire then being movable into the channel to make said contact by sliding the carrier to carry the wire into the channel. 
     In an arrangement as described in patent specification 90449/98, it has been found that there is some tendency for the conductive element to buckle when a wire is terminated, unless the conductive element is made from relatively heavy material. 
     In one aspect, the invention provides an insulation displacement contact formed from a conductive element having an aperture therein, opposed portions of the edge of the aperture defining opposed contact portions which extend inwardly towards each other and which have inner opposed contact edges which define a channel therebetween, whereby a wire having a conductor surrounded by insulation may be introduced into the channel and pressed into the channel to cut the insulation of the wire and make electrical contact between the contact edges and the conductor; the insulation displacement contact having, at opposed side edges of the conductive element, respective flanges which are generally parallel to the direction of extent of said channel and which are oppositely directed with respect to each other. Particularly, the conductive element may define a central portion which is elongate in the direction of extent of said channel, and said flanges may extend in said direction and out of the plane of the central portion to respective opposite sides of that plane. 
     The contact portions may extend from substantially fixed ends at an angle to the direction of extent of the channel so as to converge towards each other, and have free end parts which extend generally parallel to each other and which define said contact edges. Free end edges of said free end parts may extend transversely with respect to the direction of extent of said channel and diverge outwardly with respect to each other in the direction away from said substantially fixed ends to form a lead-in structure for facilitating entry of the wire into the channel. The free end edges may extend angularly with respect to said plane of the central portion and be oppositely directed with respect to that plane so as to tend to introduce displacement of the contact portions in opposite rotational directions out of said plane, when a wire is brought into contact with the free end edges for introduction into said channel. 
    
    
     The invention is further described by way of example only with reference to the accompanying drawings in which: 
     FIG. 1 is a perspective view of a prior art insulation displacement contact; 
     FIG. 2 is a front view of an insulation displacement contact constructed in accordance with the invention; 
     FIG. 3 is an enlarged fragmentary view of portion of FIG.  2  and illustrating how wires are brought into contact with the insulation displacement contact; 
     FIG. 4 is a perspective view of the insulation displacement contact of FIG. 2; 
     FIG. 5 is another perspective view of the insulation displacement contact of FIG. 4; 
     FIG. 6 is a perspective view of the insulation displacement contact of FIG. 2, connected to a conductive element; 
     FIG. 7 shows the insulation displacement connector of FIG. 2 coupled to wire carriers; 
     FIG. 8 is a perspective view of one of the wire carriers of FIG. 7; and 
     FIG. 9 is a rear view of an electrical power socket fitted with electrical connectors and wire carriers as shown in FIG.  7 . 
    
    
     The insulation displacement contact  2  shown in FIG. 1 comprises an elongate generally planar conductive element  4  having a series of apertures  6  spaced along the length thereof. The edge of each aperture  6  defines a pair of inwardly projecting contact portions  8  which define therebetween a relatively narrow channel  10 . Wires introduced into the apertures  6  by lengthwise movement of the wires transverse to the element  4  may be moved laterally, and lengthwise of the element  8 , to enter these into a channels  10  so that opposed contact edges of the portions  8  contact the wires, cut the insulation thereof and make electrical connection to inner conductors of the wires. To facilitate leading of the wire into the channel, the portions  8  may have respective leading edges  12 , and these may, as shown, the oppositely inclined with respect to the plane of the element. By this, when a wire is engaged with the edges  12  during introduction of the wire into the channel  10 , torsional displacement of the portions  8  relative to the lengthwise direction of the element  4  occurs. By this, the portions  8  are oppositely displaced relative to the plane of the element  4 . 
     The insulation displacement contact  20  of FIGS. 2 to  9  is formed from a conductive element  22  of laminar form, being generally planar. Apertures  24  are spaced along the length of the element  22 , these extending through a central portion  26  of the element  22 , and being spaced in the lengthwise direction of extent of the element  22 . In this case, there are two apertures  24 , each configured to define two respective contact structures  28 ,  30 , the contact structures  28 ,  30  of each aperture  24  being spaced in the lengthwise direction of extent of the element  22 . Since the two apertures  24  and associated contact structure  28 ,  30  are substantially the same, the following description is confined to one of these apertures and associated contact structures. 
     As best shown in FIG. 3, each of the contact structures  28 ,  30  has a pair of contact portions  32  defined by the edge of the associated aperture  24 , and which extend inwardly towards each other from opposite sides of the element  22 . Each pair of contact portions  32  defines therebetween a respective channel  42 . Each contact portion  32  has a part  32   a  which extends from a respective substantially fixed end adjacent a respective edge of the element  22 , being angularly disposed with respect to the lengthwise direction of extent of the element  22 , which direction is marked “A” in the drawings. Parts  32   a  of each pair of contact portions  32  converge towards each other in direction “A”. At outer ends of the contact portions  32 , free end parts  32   b  are defined, these extending somewhat parallel to the direction “A” and defining at inner edges thereof contact edges  32   c . The contact edges  32   c  on each pair of contact portions  32  define therebetween a respective one of the channels  42 . At free ends of the contact parts  32   b , there are provided transverse free end edges  32   d  which diverge away from each other in the direction “A”, and these define a respective lead-in structure  34  (FIG. 2) for facilitating entry of wires into the associated channel  42 . As shown, these edges  32   d  are defined by inclined surfaces, the surfaces being oppositely inclined with respect to the plane of the element  22  so that, when a wire is introduced into a channel structure  42 , as presented by a pair of edges  32   d , there is a tendency for the respective contact portions  32  to be relatively oppositely rotated relative to the lengthwise direction of the contact element  22 , and to be displaced to respective opposite sides of the plane of the element  22 . 
     Each channel  42  leads, in the direction “A”, away from the fixed ends of the contact portions  32  to an enlarged portion  24   a ,  24   b  of the respective aperture  24 . That is, there is an enlarged aperture portion  24   a  adjacent the channel  42  for the contact structure  28 , at one end of the aperture  24 , and a similar enlarged aperture portion  24   b  adjacent the contact structure  30 , at the other end of aperture  24 . 
     The aperture portions  24   a ,  24   b  also define, at opposite sides thereof, cut-out aperture parts  44  which diverge outwardly in the direction opposite to direction “A”. These define edges  36  of the contact portions  32 . As a result, as compared with the arrangement shown in FIG. 1, it will be observed that the contact portions  32  are relatively longer (“dimension “L” in FIG. 3) and of lesser width, and thus exhibit somewhat greater flexibility than exhibited by the contact elements  8  in FIG.  1 . 
     Edges  38  of the contact portions  32  of contact structure  28 , opposite edges  36  thereof, are defined by portion of the periphery of aperture portion  24   b . These edges  38  are disposed transversely with respect to the direction of extent of the element  22 , and converge in the direction “A”. Edges  38  of the contact portions  32  of the contact structure  30  are defined by another portion of the periphery of a further portion  24   c  of the aperture  24 . These edges  38  are likewise disposed transversely with respect to the direction of extent of the element  22 , and converge in the direction “A”. 
     FIG. 3 shows insulated wires  48  having internal conductors  50  surrounded by insulation  52 . The portions  24   a ,  24   b  of the aperture  24  are large enough to freely accommodate respective ones of these wires  48 , as shown, such that these wires extend normally to the plane of the central portion  26  of element  22 . Once in position as shown in FIG. 3, the wires may be moved in the direction opposite direction “A” to pass them into the channels  42  to cut the insulation  52  and make electrical connection between the contact edges  32   c  of the contact portions  32  and the conductors  50 , in a similar way to that described in FIG.  1 . 
     Further to improved effectiveness of operation, the element  22  has, at opposed longitudinal edges thereof, flanges  46 ,  47 . As shown, these are directed oppositely with respect to the plane of a central portion  26  of the element  22  so as to be one to either side of that plane. Also, as shown, these extend at an angle of approximately 45° to the plane of the central portion  26 , as viewed in section transverse to the direction of extent of the element  22 . The flanges  46 ,  47  strengthen the element  22 , and facilitate effective connection to the wires. 
     As shown in FIG. 6, the contact  20  may be connected by a suitable end portion  56  to other conductors such as the conductor  58  shown, for use in applications such as described in the mentioned Australian patent specification where connection to other circuit elements is required. 
     Also, as shown in FIG. 7, slidable carriers  60  may be fitted to the contact element  20 . In the case of FIG. 7, there are two such carriers  60 , one associated with each aperture  24 . Each carrier  60  is formed as a body  62  formed of electrically insulative material with a lengthwise extending slot  64  therethrough, which neatly slidably accommodates the element  22 , for slidable movement of the carriers  60  therealong. Each carrier  60  has two openings  66 ,  68 , these extending generally parallel to the flanges  46 ,  47  and thus at an angle of 45° to the central portion  26  of the contact element  22 . Each carrier  60 , and the openings  66 ,  68  therethrough, are arranged so that, in respective first positions of the carriers, the openings  66 ,  68  are arranged in alignment with the portions  24   a ,  24   b  of the respective apertures  24  in the element  22 . In this condition, wires may be introduced into the carriers so as to pass through the respective openings  66 ,  68  and into the portions  24   a ,  24   b  of the apertures. Thereafter, by sliding movement of the carriers  60  in the direction opposite to direction “A”, as viewed in FIG. 7, the wires are forced between the channels  42  for making electrical connection as described. 
     FIG. 9 shows an arrangement where a plurality of contacts  20  are contained within a casing  70  having respective openings associated with carriers  60  of which there are two carriers  60  for each contact  20 , as shown in FIG.  7 . The casing has slots  72  so that, when the carriers  60  are in positions for receipt of wires (as shown in FIG.  9 ), the openings  68  of the carriers are positioned at one ends of the respective slots  72 . The slots  72  are of sufficient length to enable the carriers  60  to be moved to make electrical connection as described, by movement so that the other opening  66  of each is then positioned at the opposite end of the respective slot  72 . 
     The casing  70  may for example form part of an electrical power outlet as described in Australian Patent Application No. 90449/98. 
     The described arrangement has been advanced merely by way of explanation any many modifications may be made thereto without departing from the spirit and scope of the invention which includes every novel feature and combination of novel features herein disclosed. 
     A listing of parts follows: 
     
       
         
           
               
               
               
             
               
                   
                   
               
             
            
               
                   
                 Insulation displacement contact 
                  2 
               
               
                   
                 Conductive element 
                  4 
               
               
                   
                 Apertures 
                  6 
               
               
                   
                 Projecting contact portions 
                  8 
               
               
                   
                 Channel 
                 10 
               
               
                   
                 Leading edges 
                 12 
               
               
                   
                 Insulation displacement contact 
                 20 
               
               
                   
                 Conductive element 
                 22 
               
               
                   
                 Apertures 
                 24 
               
               
                   
                 Aperture portions 
                 24a, 24b, 24c 
               
               
                   
                 Central portion 
                 26 
               
               
                   
                 Contact structures 
                 28, 30 
               
               
                   
                 Contact portions 
                 32 
               
               
                   
                 Contact parts 
                 32a 
               
               
                   
                 Contact free end parts 
                 32b 
               
               
                   
                 Contact edges 
                 32c 
               
               
                   
                 Free end edges 
                 32d 
               
               
                   
                 Lead-in structure 
                 34 
               
               
                   
                 Contact edges 
                 36, 38 
               
               
                   
                 Channel 
                 42 
               
               
                   
                 Aperture parts 
                 44 
               
               
                   
                 Flanges 
                 46, 47 
               
               
                   
                 Insulated wires 
                 48 
               
               
                   
                 Internal conductor 
                 50 
               
               
                   
                 Insulation 
                 52 
               
               
                   
                 Contact end portion 
                 56 
               
               
                   
                 Conductor 
                 58 
               
               
                   
                 Carriers 
                 60 
               
               
                   
                 Body 
                 62 
               
               
                   
                 Slot 
                 64 
               
               
                   
                 Openings 
                 66, 68 
               
               
                   
                 Casing 
                 70 
               
               
                   
                 Slot 
                 72 
               
               
                   
                   
               
            
           
         
       
     
     This specification and the claims which follow, unless the context requires otherwise, the word “comprise”, and variations such as “comprises” and “comprising”, will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.