Abstract:
An electrical connector that can be compressed onto a composite transmission line without causing catastrophic damage to the non-metal/steel core. The electrical connector comprises a sleeve and a compression regulator that limits compression of the sleeve.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 60/906,354 filed Mar. 12, 2007 which is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to an electrical connector and a method of applying an electrical connector to a transmission line. More particularly, the present invention includes imploding an electrical connector onto a transmission line that comprises a non-steel core. 
     2. Brief Description of Prior Developments 
     A method of imploding electrical connectors onto a steel core is described in “New Implosive Connector Technology for High Voltage Conductors”, Pasini, The 8th IEEE International Conference on AC and DC Power Transmission, Savoy Place, London, UK, March 2006. 
     Non-metal cores, composite cores, and linearly driven wedge connectors for composite cores are described in US Patent Publication Nos. 2004/0182597; 2004/0026112; 2004/0131851; 2005/0006129; 2005/0227067; 2006/0016616; 2006/0051580; and 2006/0084327. Each of these documents are incorporated by reference in their entirety. 
     U.S. Pat. No. 4,511,280 describes an anti-bird caging connector. This document is incorporated by reference in its entirety. 
     SUMMARY OF THE INVENTION 
     One aspect of the present invention is to attach an electrical connector to an object, such as a composite core transmission line. Non-metal/steel cores typically have a high tensile strength but also have a compression failure or crush point that is less than steel or stranded steel cable. For example, carbon composite core materials may have a compression failure or crush point of about 4000 pounds per square inch. 
     A strong frictional force is needed between the non-steel core and/or a conductor carried by the non-steel core and the electrical connector to keep the transmission line suspended above the ground. Therefore, the non-steel core has to withstand enough compressive force to frictionally secure the electrical connector to the transmission line, yet be controlled so that the non-steel core is not catastrophically damaged during the axial or radially inward compression of the non-steel core and/or the conductor. 
     The present invention is therefore directed to an electrical connector that is radially inwardly compressed onto a non-metallic or non-steel core, such as a carbon-based core. In one embodiment, the electrical connector comprises a sleeve may be radially imploded onto the non-steel core directly or onto the conductor positioned adjacent to the non-steel core. Other radial compression mechanisms, such as hydraulic or manual compression, are also contemplated. 
     In accordance with one aspect of the invention, an electrical connector is provided comprising a sleeve and a compression regulator. The sleeve comprises an electrically conductive metal material and a channel adapted to receive an end of a non-steel core. The compression regulator is configured to prevent the non-steel core from being crushed when the sleeve is radially inwardly compressed around the non-metal core. 
     An implosion section can be provide comprised of explosive material, wherein the implosion section surrounds a portion of the sleeve. The compression regulator can be comprised of a compressible material positioned adjacent to the non-metal core. The compression regulator can be comprised of a plurality of spaced apart sections that each extend from an interior surface of the sleeve. The compression regulator can comprise walls of the sleeve that are interlaced together. The sleeve can comprise two pieces or more. The compression regulator can comprise tapered slots and tapered wedges that fit into the tapered slots with an increased interference fit. The compression regulator can comprise a slot, a tab that fits into the slot, and wherein the tab is shorter in length than the slot. The compression regulator can comprise a gap in the sleeve. A compressible material can be located in the gap. The compression regulator can comprise is brakes or lands and grooves in an interior wall of the sleeve section at the channel. An interior wall of the sleeve at the channel can comprise a plurality of recesses extending into the interior wall from the channel. The compression regulator can comprise a plurality of tapered members that are separated from each other prior to compression and each extend into a respective one of the plurality of recesses. A channel can be formed by a wall of the sleeve which at least partially overlaps itself between the channel and an outer slide of the sleeve. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing aspects and other features of the invention are explained in the following description, taken in connection with the accompanying drawings, wherein: 
         FIG. 1  is an end view of a transmission line with a non-metal core and a conductor wrapped around the non-metal core; 
         FIG. 2  is a side view of the transmission line shown in  FIG. 1 ; 
         FIG. 3  is a cross-sectional side view of an electrical connector and explosive material according to one embodiment of the present invention; 
         FIG. 4  is a cross-sectional end view of an electrical connector according to a second embodiment of the present invention; 
         FIG. 5  is a cross-sectional end view of an electrical connector according to a third embodiment of the present invention; 
         FIG. 6  is a cross-sectional end view of an electrical connector according to a fourth embodiment of the present invention; 
         FIG. 7  is a cross-sectional end view of an electrical connector according to a fifth embodiment of the present invention; 
         FIG. 8  is a cross-sectional end view of an electrical connector according to a sixth embodiment of the present invention; 
         FIG. 9  is a cross-sectional end view of an electrical connector according to a seventh embodiment of the present invention; 
         FIG. 10  is a cross-sectional end view of an electrical connector according to a eighth embodiment of the present invention; 
         FIG. 11  is a cross-sectional end view of an electrical connector according to a ninth embodiment of the present invention; 
         FIG. 12  is a side view of an electrical connector according to a tenth embodiment of the present invention; 
         FIG. 13  is a cross-sectional side view of an electrical connector according to a eleventh embodiment of the present invention; 
         FIG. 14  is a cross-sectional side view of an electrical connector according to a twelfth embodiment of the present invention; 
         FIG. 15  is a cross-sectional end view of a thirteen embodiment electrical connector positioned around a composite core; 
         FIG. 16  is a partial cross-sectional end view of an electrical connector according to a fourteenth embodiment of the present invention; 
         FIG. 17  is a cross-sectional end view of an electrical connector according to a fifteenth embodiment of the present invention; 
         FIG. 18  is a perspective, exploded view of a non-metal sleeve according to a sixteenth embodiment of the present invention; and 
         FIG. 19  is a cross-sectional end view of an electrical connector according to a seventeenth embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention generally relates to attaching an electrical connector onto an electrical a transmission line comprising a non-steel core and/or a conductor wrapped around the non-steel core. 
     As shown generally in  FIGS. 1-2 , the present invention generally relates to an electrical connector  10  ( FIG. 3 ) that is adapted to connect to a non-steel core  12  and/or a conductor  14  of a transmission line T. The conductor  14  may be aluminum or some other suitable material, and in one embodiment comprises strands wrapped around the non-steel core  12 . 
     As shown generally in  FIGS. 3-19 , each electrical connector  10  ( FIG. 3 ) generally comprises a sleeve  16 - 16 P and a compression regulator. The sleeves  16 - 16 P are preferably made from steel, aluminum, plastic, conductive plastic, or other suitable material and are preferably hollow and compressible. The sleeves  16 - 16 P shown in  FIGS. 3-19  are adapted to be positioned over the non-steel core  12  or the conductor  14  shown in  FIGS. 1 and 2 . The sleeves  16 - 16 P may define an exterior surface  18 - 18 P that may be cylindrical or some other suitable shape. 
     An explosive material  20 ,  20 A ( FIGS. 3 and 8 ) may be positioned on the exterior surfaces  18 - 18 P of the sleeves  16 - 16 P. The explosive material  20 ,  20 A may be symmetrically or asymmetrically arranged along a length of the sleeves  16 - 16 P or on an exterior surface of a second sleeve that fits over the exterior surfaces  18 - 18 P of the one or more of the sleeves  16 - 16 P. A resilient spacer ( FIG. 14 ) may be positioned between the exterior surfaces  18 - 18 P of the sleeves  16 - 16 P and the explosive comprise additional interior or exterior sleeves, wedges, or wraps. 
     Interior surfaces  22 - 22 P of the sleeves  16 - 16 P may have continuous, unbroken surfaces. Alternatively, as shown in  FIGS. 4-8 ,  11 ,  12 , and  15 - 19 , the interior surfaces  22 A- 22 E,  22 H,  22 I,  22 L- 22 P of sleeves  16 A- 16 E,  16 H,  16 I,  16 L- 16 P of may also define breaks  24 , gaps  26 , or lands  40  and grooves  42 . 
     For example,  FIG. 3  shows an electrical connector  10  comprising a sleeve  16  with an interior surface  22 , and exterior surface  18 . Explosive material is positioned adjacent to the exterior surface  18  of the sleeve  16 . 
       FIG. 4  shows a sleeve  16 A with an interior surface  22 A and an exterior surface  18 A. Breaks  24  are added to help absorb energy during radial compression of the sleeve onto a non-steel core or conductor, such as the core  12  and conductor  14  shown in  FIGS. 1 and 2 . 
     As shown in  FIG. 5 , sleeve  16 B can define an interior surface  22 B, an exterior surface  18 B, and a cross-sectional C-shape with a gap  26  defined between two opposing edges of the sleeve  16 B. The opposing edges can be angled with respect to each other so that a compressible material  28  is squeezed outwardly away from the non-steel core  12  during compression. The compressive material  28  may be positioned in the gap  26  to help absorb implosive force. The gap  26  may also be sized so that only a predetermined amount of force will be exerted on the core  12  by the sleeve  16 B during according to its particular compression properties. 
       FIG. 6  shows another sleeve  16 C according to the present invention. The sleeve  16 C generally comprises several metal or non-metal sections  30  positioned on an interior surface  22 C of the sleeve  16 C that are spaced apart or do not directly touch one another prior to implosion of the sleeve  16 C. The metal or non-metal sections  30  may be held together by a flexible, perhaps sacrificial overmold  32  that may receive anchors  34  that extend from the several sections  30 . Alternatively, the metal or non-metal sections  30  may be integrally formed with a compressible over mold  32  of like material. The several sections  30  may be wedge-shaped so the sections will interfere with one another as the overmold  32  is imploded by explosives (not shown). This interference is believed to limit compressive force on the core  12 . 
       FIG. 7  shows a sleeve  16 D that overlaps over itself. Flexible material  36  such as rubber or plastic can fill in an overbite formed between overlapping edges to make the exterior surface  18 D uniform in shape. For asymmetric exterior surfaces, explosive material (not shown for clarity) can be arranged on the exterior surface  18 D of the sleeve  16 D to compensate for the overlapped metal. In addition, interior surface  22 D edges of the sleeve  16 D adjacent to the overbite can be rounded to help prevent piercing of the core  12 . 
       FIG. 8  depicts a sleeve  16 E with segmented explosive material  20 A positioned adjacent an exterior surface  18 E of the sleeve  16 E. The segmented explosive material  20 A can be detonated simultaneously or in sections to help prevent the non-steel core  12  adjacent to the interior surface  22 E of the sleeve  16 E from being crushed. The sleeve  16 E is also segmented, shown as two angled lines, to allow for more controlled compression of the sleeve  16 E during implosion. 
     The sleeve  16 F in  FIG. 9  has an exterior surface  18 F and a metal, non-metal, or semi-metallic material  38  on the interior surface  22 F of the sleeve  16 F. The material  38  may be conductive plastic, the same material of the non-steel core  12 , abrasive sponge, stainless steel, lead or lead free solder, epoxy or resin, or some other suitable material. Bonding between the core  12  and the material  38  may be enhanced by using material that is chemically similar or chemically or heat reactive with the core  12 . Moreover, if the material is resilient, compression of the non-metal core  12  beyond its compression failure point may be reduced. 
     As shown in  FIG. 10 , sleeve  16 G may have an exterior surface  18 G and an interior surface  22 G that defines lands  40  and grooves  42 . The lands  40  and grooves  42  may be parallel to each other and may form a spiraled rifling pattern. The lands  40  may be positioned opposite each other so that there are equal and opposite compressive forces on the core  12  during implosion of the sleeve  16 G on the core  12  or the conductor  14  ( FIG. 2 ). 
       FIG. 11  is another embodiment of the present invention. Sleeve  16 H may define an exterior surface  18 H, an interior surface  22 H, and a radiused slot  44  that receives a radiused tab  46  that is shorter in length than a depth of the radiused slot  44 . The sleeve  16 H may compress around the non-steel core  12  or conductor  14  and the slot  44 , tab  46 , or surfaces  48 A,  48 B restrict the amount of allowable compression during implosion or other suitable radial compression. 
       FIG. 12  shows a sleeve  16 I that comprises an exterior surface  18 I and a serrated seam  50  defined by edges  52 A,  52 B of sleeve  16 I. The edges  52 A,  52 B may define teeth and grooves that allow movement of the edges  52 A,  52 B with respect to each other, yet restrict the movement of the edges  52 A,  52 B to a predetermined distance during implosion. The teeth and grooves may be tapered to form an increasing interference fit as the sleeve  16 I is compressed. 
     As shown in  FIGS. 13 and 14 , the exterior surfaces  18 J,  18 K or the interior surface  22 J,  22 K of sleeves  16 J and  16 K may be tapered in appearance. Plastic P, shown in  FIG. 14 , may be positioned on the exterior surface of the sleeves  16 - 16 O. 
       FIG. 15  shows a sleeve  16 L with interior lands  40 L and grooves  42 L that are provided to prevent bird-caging of a conductor  14  wrapped around an exterior surface of the non-steel core  12 . In the  FIG. 15  embodiment, the lands  40 L and grooves  42 L are cut into the interior surface  22 L of the sleeve  16 L and the exterior surface  18 L may be uniform in shape. Alternatively, the interior surface  22 L may be smooth or comprise lands  40 L and grooves  42 L. 
       FIG. 16  shows a sleeve  16 M with a tab  46 M on one connector piece and a slot  54 M on a second connector piece. The tab  46 M has a width greater than a gap width GW of the slot  54 M. The second connector piece may further define a recess  56  that can receive metal shavings from the tab  46 M as the first and second connector pieces are driven together by radial compression, such as by an explosive charge positioned on exterior surfaces  18 M of the two part sleeve  16 M. Upstanding walls  58  should be thick enough to prevent bowing away from the tab  46 M during compression. The interior surface  22 M may be smooth or comprise lands  40 M and grooves  42 M. The exterior surface  18 M may be uniform on non-uniform in cross-section. The tabs  46 M and slots  54 M may form an increasing interference fit as they are compressed together. 
       FIG. 17  shows a two or more part sleeve  16 N with opposed tabs  46 N and slots  54 N. The tabs  46 N are preferably slightly larger in tapered width than the corresponding tapered slots  54 N. The tabs  46 N and slots  54 N may form an increasing interference fit as they are compressed together. The interior surface  22 N may be smooth or comprise lands  40 N and grooves  42 N. The exterior surface  18 M may be uniform on non-uniform in cross-section. Sleeve separators may be included as discussed below. 
       FIG. 18  is a non-metal inner sleeve  16 O similar to the  FIG. 17  sleeve  16 N. Sleeve  16 O is a compression regulator that may fit inside an outer metal sleeve (not shown). Both the sleeve  16 O and the outer metal sleeve are compressed. The non-metal sleeve contacts the non-steel core  12  ( FIG. 1 ) and the outer metal sleeve makes electrical connection with the conductor  14  ( FIG. 1 ). Explosive material  20 ,  20 A discussed above may be positioned around the outer metal sleeve. 
       FIG. 19  shows a three-part sleeve  16 P. The three-part sleeve is similar to the sleeve  16 N shown in  FIG. 17 . A removable or sacrificial spacer  60  may be included for manufacturing uniformity. The interior surface  22 P of the sleeve  16 P may be smooth or comprise lands  40 P and grooves  42 P. The exterior surface  18 P may be uniform on non-uniform in cross-section. 
     Many modifications and other embodiments of the invention will come to the mind of one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and associated drawings. For example, the sleeves  16 - 16 P can be compressed or torqued with hydraulic tools, by hand, or with torque clamps to a pre-determined compression force that prevents core failure yet still holds the transmission line off of the ground. Accordingly, it is understood that the invention is not to be limited to the illustrated embodiments disclosed, and that other modifications and embodiments are intended to be included within the spirit and scope of this disclosure. Combinations of features of the various embodiments described above could also be included in other embodiments.