CA3177702A1 - Core retention compression clamp and method of installation - Google Patents
Core retention compression clamp and method of installationInfo
- Publication number
- CA3177702A1 CA3177702A1 CA3177702A CA3177702A CA3177702A1 CA 3177702 A1 CA3177702 A1 CA 3177702A1 CA 3177702 A CA3177702 A CA 3177702A CA 3177702 A CA3177702 A CA 3177702A CA 3177702 A1 CA3177702 A1 CA 3177702A1
- Authority
- CA
- Canada
- Prior art keywords
- core
- clamp
- combination
- core retention
- stranded conductor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
- H01B1/20—Conductive material dispersed in non-conductive organic material
- H01B1/22—Conductive material dispersed in non-conductive organic material the conductive material comprising metals or alloys
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
- H01B1/02—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors mainly consisting of metals or alloys
- H01B1/023—Alloys based on aluminium
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02G—INSTALLATION OF ELECTRIC CABLES OR LINES, OR OF COMBINED OPTICAL AND ELECTRIC CABLES OR LINES
- H02G1/00—Methods or apparatus specially adapted for installing, maintaining, repairing or dismantling electric cables or lines
- H02G1/02—Methods or apparatus specially adapted for installing, maintaining, repairing or dismantling electric cables or lines for overhead lines or cables
- H02G1/04—Methods or apparatus specially adapted for installing, maintaining, repairing or dismantling electric cables or lines for overhead lines or cables for mounting or stretching
Landscapes
- Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- Dispersion Chemistry (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Suspension Of Electric Lines Or Cables (AREA)
- Connections Effected By Soldering, Adhesion, Or Permanent Deformation (AREA)
Abstract
A core retention clamp that is an elongated member having a bore extending therethrough and an outer surface. The core retention clamp can be utilized with an installation system to install an electrical conductor having a composite core surrounded by a stranded conductor. The core retention clamp facilitates the coupling of the pulling grip with the composite core so that relative movement of the composite core and the stranded conductor is minimized.
Description
2 TITLE
CORE RETENTION COMPRESSION CLAMP AND METHOD OF INSTALLATION
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority from U.S. Provisional Application No.
63/019,285 filed May 2, 2020, entitled CORE RETENTION COMPRESSION CLAMP AND
METHOD OF INSTALLATION OF AN ELECTRICAL CONDUCTOR HAVING A
COMPOSITE CORE, the entire specification of which is hereby incorporated by reference.
[0002] This application claims makes reference to and is related to (but does not claim priority from) from U.S. Patent Application Serial No. 12/070,244, filed February 15, 2008, entitled -Electrical Conductor and Core for An Electrical Conductor", now U.S.
Patent No.
7,705,242 issued April 27, 2010, the entire specification of which is hereby incorporated by reference.
BACKGROUND OF THE DISCLOSURE
CORE RETENTION COMPRESSION CLAMP AND METHOD OF INSTALLATION
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority from U.S. Provisional Application No.
63/019,285 filed May 2, 2020, entitled CORE RETENTION COMPRESSION CLAMP AND
METHOD OF INSTALLATION OF AN ELECTRICAL CONDUCTOR HAVING A
COMPOSITE CORE, the entire specification of which is hereby incorporated by reference.
[0002] This application claims makes reference to and is related to (but does not claim priority from) from U.S. Patent Application Serial No. 12/070,244, filed February 15, 2008, entitled -Electrical Conductor and Core for An Electrical Conductor", now U.S.
Patent No.
7,705,242 issued April 27, 2010, the entire specification of which is hereby incorporated by reference.
BACKGROUND OF THE DISCLOSURE
[0003] 1. Field of the Disclosure
[0004] The disclosure relates in general to installation of electrical transmission and distribution cables, and more particularly, to a core retention clamp, compression clamp or "Core Retention Clamp configured to engage a composite core, to, in turn, facilitate the installation of an electrical cable.
[0005] 2. Background Art [0001] The demand for transmission and distribution cables increases with the greater demand for electricity. As the appetite for power increases, new electrical cables continue to be installed. Additionally, to increase capacity, existing electrical installations are rewired with cables of greater capacity.
[0002] Traditionally, such electrical cables comprise a central stranded steel core which is wrapped in a stranded aluminum conductor. Such cables have been utilized for decades with very little change. Among other drawbacks, such cables are susceptible to excessive sag in certain climates and under certain operating conditions. Furthermore, such cables are susceptible to corrosion in other environments, and have other disadvantages which result in performance limitations.
[0003] To combat the shortcomings, other composite based solutions have been developed. Certain such solutions are described in U.S. Pat. No. 7,060,326;
U.S. Pub. Nos. 2004-0131834; 2004-0131851; 2005-0227067; 2005-0129942; 2005-0186410; 2006-0051580;
U.S.
Prov. Pat. App. No. 60/374,879; and PCT Pub. No. WO 03/091008, the entire disclosures of each of the foregoing are incorporated herein by reference in their entirety.
Additionally, the above-incorporated patent likewise proposes a solution.
[0002] Traditionally, such electrical cables comprise a central stranded steel core which is wrapped in a stranded aluminum conductor. Such cables have been utilized for decades with very little change. Among other drawbacks, such cables are susceptible to excessive sag in certain climates and under certain operating conditions. Furthermore, such cables are susceptible to corrosion in other environments, and have other disadvantages which result in performance limitations.
[0003] To combat the shortcomings, other composite based solutions have been developed. Certain such solutions are described in U.S. Pat. No. 7,060,326;
U.S. Pub. Nos. 2004-0131834; 2004-0131851; 2005-0227067; 2005-0129942; 2005-0186410; 2006-0051580;
U.S.
Prov. Pat. App. No. 60/374,879; and PCT Pub. No. WO 03/091008, the entire disclosures of each of the foregoing are incorporated herein by reference in their entirety.
Additionally, the above-incorporated patent likewise proposes a solution.
[0006] While these solutions have introduced the use of composite members as the strength member of the core over which conductors are stranded, the use of such cores requires different installation practices. For example, due to the smooth outer surface of the composite core, if the installer employs conventional installation techniques, the core may be inadvertently released during installation so that the composite core is separated from the aluminum strands and recedes from the a aluminum strands, often more than 1,000 meters leaving a hollow cylindrical void in the center of the aluminum strands where the core had previously been. Such separation of the two components leads to catastrophic failures if the problem is not rectified prior to installation. Even where the failure has been recognized, it is often costly and time consuming to rectify the cable the core slippage because the entire section of cable SUMMARY OF THE DISCLOSURE
[0007] In one aspect the disclosure is directed to a combination electrical core and core retention member comprising an electrical core and a core retention clamp. The electrical core comprises a composite core with a stranded conductor extending therearound. A
portion of the composite core extends beyond the stranded conductor. The core retention clamp comprises an elongated member having a first end and a second end and defining an outer surface, with a bore extending from the first end to the second end. The the core extends through the bore of the core retention clamp such that the second end of the core is positioned proximate the stranded conductor, and wherein at least a portion of the core retention clamp is crimped to the composite core.
portion of the composite core extends beyond the stranded conductor. The core retention clamp comprises an elongated member having a first end and a second end and defining an outer surface, with a bore extending from the first end to the second end. The the core extends through the bore of the core retention clamp such that the second end of the core is positioned proximate the stranded conductor, and wherein at least a portion of the core retention clamp is crimped to the composite core.
[0008] In some configurations, the composite core comprises a plurality of fibers in a resin matrix.
[0009] In some configurations, the stranded conductor comprises a plurality of helically wound conductor strands.
[0010] In some configurations, the conductor strands comprise one of aluminum alloy and annealed aluminum.
[0011] In some configurations, the outer surface of the core retention clamp comprises a cylindrical configuration where not crimped, and a polygonal configuration where crimped.
[0012] In some configurations, a portion of the core retention clamp proximate the second end remains not crimped.
[0013] In some configurations, the portion that is crimped is spaced apart from the second end.
[0014] In some configurations, approximately 50% of the core retention clamp between the first and second end thereof is crimped to the composite core.
[0015] In some configurations, the second end of the core retention clamp is spaced apart from the stranded conductor.
[0016] In some configurations, the core retention clamp has a clamp hardness, and wherein the composite core has a core hardness, with the clamp hardness being 60% to 95% the hardness of the composite core, and more preferably between 70% and 90% and more preferably between 75% and 85%.
[0017] In some configurations, the core retention clamp comprises a 6061-T6 Aluminum.
[0018] In some configurations, the combination further comprises a pulling grip having a grasping eye, a shoulder extending from the grasping eye, and a multiweave mesh grip member extending from the grasping eye. The multiweave mesh grip extends over the core retention clamp, the composite core and the stranded conductor. At least one clamp is configured to clamp the multiweave mesh grip member to the stranded conductor. At least one clamp configured to clamp the multiweave mesh grip member to the core retention clamp.
[0019] In some configurations, the at least one clamp configured to clamp the multiweave mesh to the core retention clamp extends over a portion of the core retention clamp that is not crimped to the composite core.
[0020] In some configurations, the combination further comprises electrical tape extending over the stranded conductor between the multiweave mesh and the stranded conductor.
[0021] In some configurations, the outer surface of the core retention clamp and the bore are concentric.
[0022] In some configurations, the crimp defines a polygonal outer surface, and the not crimped portion defines a cylindrical configuration.
[0023] In another aspect of the disclosure, the disclosure is directed to a method of installation of an electrical conductor having a composite core comprising the steps of:
providing an electrical conductor having a composite core and a stranded conductor extending therearound, with a portion of the composite core extending beyond the stranded conductor;
providing a core retention member having a first end and a second end, with, a bore extending therethrough; extending the composite core through the bore of the core retention member; and crimping at least a portion of the core retention member to the composite core.
providing an electrical conductor having a composite core and a stranded conductor extending therearound, with a portion of the composite core extending beyond the stranded conductor;
providing a core retention member having a first end and a second end, with, a bore extending therethrough; extending the composite core through the bore of the core retention member; and crimping at least a portion of the core retention member to the composite core.
[0024] In some configurations, the step of extending further comprises the step of stopping the composite core prior to contact with the stranded conductor so that the core retention member is spaced apart from the stranded core.
[0025] In some configurations, the step of crimping further comprises the step of ceasing crimping prior to the second end of the core retention member so that a portion of the core retention member proximate the second end is not crimped to the composite core.
[0026] In some configurations, the step of crimping comprises the step of applying a crimping force with a hydraulic press to the outer surface of the core retention member deforming the outer surface into a polygonal configuration.
[0027[ In some configurations, the polygonal configuration comprises a hexagonal configuration.
[0028] In some configurations, the step of crimping further comprises the step of repeatedly crimping the core retention member to the composite core through overlapping crimps.
[0029] In some configurations, the method further includes the steps of: providing a pulling grip having a multiweave mesh grip member; directing the multiweave mesh grip member over the composite core, the core retention member and the stranded conductor; first applying at least one clamp to the multiweave mesh grip member to clamp the multiweave mesh grip member to the stranded conductor; and second applying at least one clamp to the core retention member to clamp the multiweave mesh grip member to the core retention member.
[0030] In some configurations, the method further includes the step of applying an electrical tape over the stranded conductor prior to the step of directing the multiweave mesh grip member.
[0031] In some configurations, for the step of second applying, the at least one clamp extends over a not crimped portion of the core retention member.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] The disclosure will now be described with reference to the drawings wherein:
[0033] Figure 1 of the drawings is a perspective view of the core retention clamp of the present disclosure;
[0034] Figure 2 of the drawings is a side elevational view of the core retention clamp of the present disclosure;
[0035] Figure 3 of the drawings is a front elevational view of the core retention clamp of the present disclosure;
[0036] Figure 4 of the drawings is a partial perspective view of the electrical conductor for use in association with the present disclosure;
[0037] Figure 5 of the drawings is a schematic representation of a plurality of electrical transmission towers with an installation cable suspended therefrom that is coupled to the end of an electrical cable wound on a drum;
[0038] Figure 6 of the drawings is an exemplary configuration of a pulling grip utilized with the present disclosure;
[0039] Figure 7 of the drawings is an exemplary hydraulic press configured for use in association with the present disclosure;
[0040] Figure 8 of the drawings is an exemplary view of the core retention clamp slid over a composite core and spaced apart from the end of the stranded conductor prior to crimping with a hydraulic press or other structure which can apply force sufficient to crimp the core retention clamp;
[0041] Figure 9 of the drawings is an exemplary view of that which is shown in Figure 8 with the core retention clamp crimped to the composite core; and [0042] Figure 10 of the drawings is an exemplary view of the installation system installed over the core retention clamp and the electrical cable once the core retention clamp is crimped to the composite core.
DETAILED DESCRIPTION OF THE DISCLOSURE
[0043] While this disclosure is susceptible of embodiment in many different forms, there is shown in the drawings and described herein in detail a specific embodiment(s) with the understanding that the present disclosure is to be considered as an exemplification and is not intended to be limited to the embodiment(s) illustrated.
[0044] It will be understood that like or analogous elements and/or components, referred to herein, may be identified throughout the drawings by like reference characters. In addition, it will be understood that the drawings are merely schematic representations of the invention, and some of the components may have been distorted from actual scale for purposes of pictorial clarity.
[0045] Referring now to the drawings and in particular to Figure 1, the core retention clamp is shown generally at 10. The core retention clamp 10 is utilized in a method of installing an electrical conductor, such as electrical conductor 100, that is installed on transmission and/or distribution towers 150 (Figures 4 and 5). One example of such an electrical conductor is disclosed in the above-incorporated issued '242 patent. Of course, other electrical conductors are likewise contemplated as being useable with the present core retention clamp.
[0046] In the configuration shown, the electrical core 100 includes composite core 102 and stranded conductor 104. Typically, the composite core 102 includes a plurality of fibers that are embedded in a resin matrix. The stranded conductor comprises a plurality of typically helically wound conductor strands, often formed from an annealed aluminum or aluminum alloy. Of course, other materials are contemplated. The strands typically have a cross-sectional configuration that is trapezoidal, round, square or other shape.
[0047] It will be understood that typically, long runs of electrical conductor are strung across a number of towers. The electrical conductor may be initially wound on a drum and the entire run may be several kilometers long (if not longer, and of course, it may be shorter). As will be described in greater detail below, and with reference to Figure 2, an installation cable is extended over typically pullies on the towers in a configuration wherein the electrical conductor is to be positioned. The end of the installation cable is coupled to the end of the electrical conductor. The installation cable is then pulled which pulls the electrical conductor into the proper orientation on the tower. The installation cable is pulled until the entirety of the conductor (or a desired portion thereof) is properly positioned so that installation can then be completed with the electrical conductor in its initial position hanging or otherwise coupled to the tower.
[0048] The core retention clamp 10 is utilized in conjunction with installation system 200, of which the installation cable 212 forms a portion thereof Problematically, due to the configuration and the properties of the composite core, it is difficult to utilize conventional installation techniques to retain the composite core and to maintain the integrity of the relationship and relative position of the composite core and the stranded conductor. In many instances, the prior art conventional techniques that work on stranded steel core can destroy composite cores and also, the properties of stranded steel cores differ greatly from composite cores. The installation and operation will be discussed in greater detail below.
[0049] The core retention clamp 10 comprises an elongated member that is defined by a first end 20, a second end 22, and an outer surface 26. A bore 24 is defined as extending from first end 20 to second 22. The first and second ends 20, 22, define a first end surface 36 and a second end surface 38, respectively. The bore includes a first end chamfer 30 where the bore meets the first end surface 36 and a second end chamfer 32 where the bore meets the second end surface 38. The bore 24 is further defined by the inner surface 34.
[0050] In the configuration shown, the core retention clamp defines a cylindrical ring having an inner surface 34 and an outer surface 26. In the configuration shown, the two surfaces are substantially concentric members. Additionally, the two surfaces have a circular cross-sectional configuration. Further still, the configuration is substantially uniform along the length of the core retention clamp. Of course, in other configurations, the outer surface and the inner surface may be offset (i.e., not concentric), and the cross-sectional configuration can be varied along the length of the configuration.
[0051] The dimensions of the core retention clamp are varied depending on the configuration of the composite cable that is being installed. Below is a chart of some preferred dimensional configurations of the core retention clamp, with the understanding that A is the overall length of the core retention clamp, B is the diameter of the outer surface in cross-section and C is the diameter of the bore. Again, these are meant to be exemplary and not limiting. All dimensions are in inches.
Type of Electrical A
Conductor Size Linnet 3 75 25 Hawk 3 .875 .29688 Drake 3 1.125 .39063 [0052] It will be understood that the hardness of the material from which the core retention clamp is formed (at least the portion proximate the inner surface) is 60% to 95%, and more preferably 70% to 90%, and more preferably 75% to 85% of the hardness of the composite core. In the configuration shown, the material from which the core retention clamp is formed comprises a 6061-T6 aluminum. Of course, other materials are contemplated for use, bearing in mind the guidelines for hardness. It has been found that the material specified and the ranges specified yield a configuration that protects the composite core from cracking and the like, while forming a strong engagement with the composite core so as to preclude relative movement therebetween.
[0053] With reference to Figures 6 and 7, the installation system 200 further includes pulling grip 202, clamps 210 and installation cable 212. The pulling grip 202 comprises grasping eye 204, shoulder 206 and multiweave mesh grip member 208 defining an elongated bore 209.
Such pulling grips are known for grasping the end of a cable and being secured thereto. One such pulling grip is available from Hubbell Wiring Device ¨ Kellems of Sheldon, Connecticut.
Of course, the disclosure is not limited to such a pulling grip.
[0054] In operation, that is, and with reference to Figures 8-10, in cooperation with Figures 4 and 5, in an installation of an electrical conductor (i.e., an overhead transmission line application), the installation system 200 is utilized in cooperation with core retention clamp 10 to string electrical conductor 100 across a plurality of overhead towers 150.
Specifically, the electrical conductor is first prepared. Generally, a portion of the stranded conductor 104 is removed from the end that is to be coupled (i.e., the first end of the electrical cable) exposing the composite core 102. For example, it is contemplated that approximately 4 inches of stranded conductor can be removed to expose the underlying composite core.
[0055] Once the composite core is exposed, it is generally beneficial to apply a clamp or electrical tape around the stranded conductor to keep the same from unraveling or unstranding.
Next, the core retention clamp is slid over the exposed composite conductor preferably stopping short of the conductor strands so as to leave a gap therebetvveen. Preferably, a spacing of approximately 2cm is maintained between the second end 22 of the core retention clamp and the end of the stranded conductor. Such a configuration is shown in Figure 8.
[0056] Once positioned, a hydraulic press (such as the hydraulic press shown in Figure 7) crimps the core retention clamp 10 to the composite core. In the configuration contemplated, and in many installations, it is often common to find the use of a 100 ton hydraulic press. Such a press can be utilized (with dies that tend to form a generally hexagonal configuration). It is desirable and/or preferable that 1.5 inch crimps are made from the center toward the first end 20.
Preferably, the crimps are made so as to be overlapping. Preferably, the crimps stop short of the second end 32. In the configuration shown, the crimps cover approximately half of the length of the core retention clamp.
[0057] Once the core retention clamp is crimped to the composite core, the pulling grip 202 can be installed by inserting the end of the electrical conductor into the elongated bore 209.
In some configurations, clamps, such as clamps 210 can be utilized over the wire multiweave mesh grip 208 to further aid securement. One such clamp is available from the same manufacturer as the pulling grip, under the term Pulling Grip Punch-Lok Band.
These bands may likewise be utilized to clamp the wire multiweave mesh grip 208 to the outer surface 26 of the core retention clamp. Once secured, the installation cable can be coupled to the grasping eye 204.
[0058] Subsequently, the installation cable can be pulled back across the towers, thereby pulling the electrical cable onto the towers. In many instances, an installation team does not finish the setting of a line in a single day. Rather, such an installation occurs over a period of weeks, days and hours. If the cable is not attached to a tower with a dead end and left overnight, or for a greater period of time, it is often the case that materials relax or plastically deform and existing tension on the partially installed cable can lead to disruption and failure due to relative movement between the core and the stranded conductor. If a wire multiweave mesh grip is placed over the cable and the to hold the cable ovemignt or longer. In the configuration described and forming the disclosure, it has been found that such relative movement has been substantially precluded as the core to pulling grip coupling is fortified and maintained through the core retention clamp and the core retention clamp's plastic deformation relative to the composite core and the strong interference therebetween.
[0059] The foregoing description merely explains and illustrates the disclosure and the disclosure is not limited thereto except insofar as the appended claims are so limited, as those skilled in the art who have the disclosure before them will be able to make modifications without departing from the scope of the disclosure.
[0027[ In some configurations, the polygonal configuration comprises a hexagonal configuration.
[0028] In some configurations, the step of crimping further comprises the step of repeatedly crimping the core retention member to the composite core through overlapping crimps.
[0029] In some configurations, the method further includes the steps of: providing a pulling grip having a multiweave mesh grip member; directing the multiweave mesh grip member over the composite core, the core retention member and the stranded conductor; first applying at least one clamp to the multiweave mesh grip member to clamp the multiweave mesh grip member to the stranded conductor; and second applying at least one clamp to the core retention member to clamp the multiweave mesh grip member to the core retention member.
[0030] In some configurations, the method further includes the step of applying an electrical tape over the stranded conductor prior to the step of directing the multiweave mesh grip member.
[0031] In some configurations, for the step of second applying, the at least one clamp extends over a not crimped portion of the core retention member.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] The disclosure will now be described with reference to the drawings wherein:
[0033] Figure 1 of the drawings is a perspective view of the core retention clamp of the present disclosure;
[0034] Figure 2 of the drawings is a side elevational view of the core retention clamp of the present disclosure;
[0035] Figure 3 of the drawings is a front elevational view of the core retention clamp of the present disclosure;
[0036] Figure 4 of the drawings is a partial perspective view of the electrical conductor for use in association with the present disclosure;
[0037] Figure 5 of the drawings is a schematic representation of a plurality of electrical transmission towers with an installation cable suspended therefrom that is coupled to the end of an electrical cable wound on a drum;
[0038] Figure 6 of the drawings is an exemplary configuration of a pulling grip utilized with the present disclosure;
[0039] Figure 7 of the drawings is an exemplary hydraulic press configured for use in association with the present disclosure;
[0040] Figure 8 of the drawings is an exemplary view of the core retention clamp slid over a composite core and spaced apart from the end of the stranded conductor prior to crimping with a hydraulic press or other structure which can apply force sufficient to crimp the core retention clamp;
[0041] Figure 9 of the drawings is an exemplary view of that which is shown in Figure 8 with the core retention clamp crimped to the composite core; and [0042] Figure 10 of the drawings is an exemplary view of the installation system installed over the core retention clamp and the electrical cable once the core retention clamp is crimped to the composite core.
DETAILED DESCRIPTION OF THE DISCLOSURE
[0043] While this disclosure is susceptible of embodiment in many different forms, there is shown in the drawings and described herein in detail a specific embodiment(s) with the understanding that the present disclosure is to be considered as an exemplification and is not intended to be limited to the embodiment(s) illustrated.
[0044] It will be understood that like or analogous elements and/or components, referred to herein, may be identified throughout the drawings by like reference characters. In addition, it will be understood that the drawings are merely schematic representations of the invention, and some of the components may have been distorted from actual scale for purposes of pictorial clarity.
[0045] Referring now to the drawings and in particular to Figure 1, the core retention clamp is shown generally at 10. The core retention clamp 10 is utilized in a method of installing an electrical conductor, such as electrical conductor 100, that is installed on transmission and/or distribution towers 150 (Figures 4 and 5). One example of such an electrical conductor is disclosed in the above-incorporated issued '242 patent. Of course, other electrical conductors are likewise contemplated as being useable with the present core retention clamp.
[0046] In the configuration shown, the electrical core 100 includes composite core 102 and stranded conductor 104. Typically, the composite core 102 includes a plurality of fibers that are embedded in a resin matrix. The stranded conductor comprises a plurality of typically helically wound conductor strands, often formed from an annealed aluminum or aluminum alloy. Of course, other materials are contemplated. The strands typically have a cross-sectional configuration that is trapezoidal, round, square or other shape.
[0047] It will be understood that typically, long runs of electrical conductor are strung across a number of towers. The electrical conductor may be initially wound on a drum and the entire run may be several kilometers long (if not longer, and of course, it may be shorter). As will be described in greater detail below, and with reference to Figure 2, an installation cable is extended over typically pullies on the towers in a configuration wherein the electrical conductor is to be positioned. The end of the installation cable is coupled to the end of the electrical conductor. The installation cable is then pulled which pulls the electrical conductor into the proper orientation on the tower. The installation cable is pulled until the entirety of the conductor (or a desired portion thereof) is properly positioned so that installation can then be completed with the electrical conductor in its initial position hanging or otherwise coupled to the tower.
[0048] The core retention clamp 10 is utilized in conjunction with installation system 200, of which the installation cable 212 forms a portion thereof Problematically, due to the configuration and the properties of the composite core, it is difficult to utilize conventional installation techniques to retain the composite core and to maintain the integrity of the relationship and relative position of the composite core and the stranded conductor. In many instances, the prior art conventional techniques that work on stranded steel core can destroy composite cores and also, the properties of stranded steel cores differ greatly from composite cores. The installation and operation will be discussed in greater detail below.
[0049] The core retention clamp 10 comprises an elongated member that is defined by a first end 20, a second end 22, and an outer surface 26. A bore 24 is defined as extending from first end 20 to second 22. The first and second ends 20, 22, define a first end surface 36 and a second end surface 38, respectively. The bore includes a first end chamfer 30 where the bore meets the first end surface 36 and a second end chamfer 32 where the bore meets the second end surface 38. The bore 24 is further defined by the inner surface 34.
[0050] In the configuration shown, the core retention clamp defines a cylindrical ring having an inner surface 34 and an outer surface 26. In the configuration shown, the two surfaces are substantially concentric members. Additionally, the two surfaces have a circular cross-sectional configuration. Further still, the configuration is substantially uniform along the length of the core retention clamp. Of course, in other configurations, the outer surface and the inner surface may be offset (i.e., not concentric), and the cross-sectional configuration can be varied along the length of the configuration.
[0051] The dimensions of the core retention clamp are varied depending on the configuration of the composite cable that is being installed. Below is a chart of some preferred dimensional configurations of the core retention clamp, with the understanding that A is the overall length of the core retention clamp, B is the diameter of the outer surface in cross-section and C is the diameter of the bore. Again, these are meant to be exemplary and not limiting. All dimensions are in inches.
Type of Electrical A
Conductor Size Linnet 3 75 25 Hawk 3 .875 .29688 Drake 3 1.125 .39063 [0052] It will be understood that the hardness of the material from which the core retention clamp is formed (at least the portion proximate the inner surface) is 60% to 95%, and more preferably 70% to 90%, and more preferably 75% to 85% of the hardness of the composite core. In the configuration shown, the material from which the core retention clamp is formed comprises a 6061-T6 aluminum. Of course, other materials are contemplated for use, bearing in mind the guidelines for hardness. It has been found that the material specified and the ranges specified yield a configuration that protects the composite core from cracking and the like, while forming a strong engagement with the composite core so as to preclude relative movement therebetween.
[0053] With reference to Figures 6 and 7, the installation system 200 further includes pulling grip 202, clamps 210 and installation cable 212. The pulling grip 202 comprises grasping eye 204, shoulder 206 and multiweave mesh grip member 208 defining an elongated bore 209.
Such pulling grips are known for grasping the end of a cable and being secured thereto. One such pulling grip is available from Hubbell Wiring Device ¨ Kellems of Sheldon, Connecticut.
Of course, the disclosure is not limited to such a pulling grip.
[0054] In operation, that is, and with reference to Figures 8-10, in cooperation with Figures 4 and 5, in an installation of an electrical conductor (i.e., an overhead transmission line application), the installation system 200 is utilized in cooperation with core retention clamp 10 to string electrical conductor 100 across a plurality of overhead towers 150.
Specifically, the electrical conductor is first prepared. Generally, a portion of the stranded conductor 104 is removed from the end that is to be coupled (i.e., the first end of the electrical cable) exposing the composite core 102. For example, it is contemplated that approximately 4 inches of stranded conductor can be removed to expose the underlying composite core.
[0055] Once the composite core is exposed, it is generally beneficial to apply a clamp or electrical tape around the stranded conductor to keep the same from unraveling or unstranding.
Next, the core retention clamp is slid over the exposed composite conductor preferably stopping short of the conductor strands so as to leave a gap therebetvveen. Preferably, a spacing of approximately 2cm is maintained between the second end 22 of the core retention clamp and the end of the stranded conductor. Such a configuration is shown in Figure 8.
[0056] Once positioned, a hydraulic press (such as the hydraulic press shown in Figure 7) crimps the core retention clamp 10 to the composite core. In the configuration contemplated, and in many installations, it is often common to find the use of a 100 ton hydraulic press. Such a press can be utilized (with dies that tend to form a generally hexagonal configuration). It is desirable and/or preferable that 1.5 inch crimps are made from the center toward the first end 20.
Preferably, the crimps are made so as to be overlapping. Preferably, the crimps stop short of the second end 32. In the configuration shown, the crimps cover approximately half of the length of the core retention clamp.
[0057] Once the core retention clamp is crimped to the composite core, the pulling grip 202 can be installed by inserting the end of the electrical conductor into the elongated bore 209.
In some configurations, clamps, such as clamps 210 can be utilized over the wire multiweave mesh grip 208 to further aid securement. One such clamp is available from the same manufacturer as the pulling grip, under the term Pulling Grip Punch-Lok Band.
These bands may likewise be utilized to clamp the wire multiweave mesh grip 208 to the outer surface 26 of the core retention clamp. Once secured, the installation cable can be coupled to the grasping eye 204.
[0058] Subsequently, the installation cable can be pulled back across the towers, thereby pulling the electrical cable onto the towers. In many instances, an installation team does not finish the setting of a line in a single day. Rather, such an installation occurs over a period of weeks, days and hours. If the cable is not attached to a tower with a dead end and left overnight, or for a greater period of time, it is often the case that materials relax or plastically deform and existing tension on the partially installed cable can lead to disruption and failure due to relative movement between the core and the stranded conductor. If a wire multiweave mesh grip is placed over the cable and the to hold the cable ovemignt or longer. In the configuration described and forming the disclosure, it has been found that such relative movement has been substantially precluded as the core to pulling grip coupling is fortified and maintained through the core retention clamp and the core retention clamp's plastic deformation relative to the composite core and the strong interference therebetween.
[0059] The foregoing description merely explains and illustrates the disclosure and the disclosure is not limited thereto except insofar as the appended claims are so limited, as those skilled in the art who have the disclosure before them will be able to make modifications without departing from the scope of the disclosure.
Claims
1. A combination electrical core and core retention member comprising:
- an electrical core having a composite core with a stranded conductor extending therearound, wherein a portion of the composite core extends beyond the stranded conductor;
- a core retention clamp comprising an elongated member haying a first end and a second end and defining an outer surface, with a bore extending from the first end to the second end;
- wherein the core extends through the bore of the core retention clamp such that the second end of the core is positioned proximate the stranded conductor, and wherein at least a portion of the core retention clamp is crimped to the composite core.
2. The combination of claim 1 wherein the composite core comprises a plurality of fibers in a resin matrix.
3. The combination of claim 2 wherein the stranded conductor comprises a plurality of helically wound conductor strands.
4. The combination of claim 3 wherein the conductor strands comprise one of aluminum alloy and anneal ed aluminum.
5. The combination of claim 1 wherein the outer surface of the core retention clamp comprises a cylindrical configuration where not crimped, and a polygonal configuration where crimped.
6. The combination of claim 1 wherein a portion of the core retention clamp proximate the second end remains not crimped.
7. The combination of claim 1 wherein the portion that is crimped is spaced apart from the second end.
8. The combination of claim 7 wherein approximately SO% of the core retention clamp between the first and second end thereof is crimped to the composite core.
9. The combination of claim 1 wherein the second end of the core retention clamp is spaced apart from the stranded conductor.
10. The combination of claim 1 wherein the core retention clamp has a clamp hardness, and wherein the composite core has a core hardness, with the clamp hardness being 60% to 95% the hardness of the composite core, and more preferably between 70% and 90% and more preferably between 75% and 85%.
11. The combination of claim 1 wherein the core retention clamp comprises a Aluminum.
12. The combination of claim 1 further comprising a pulling grip having a grasping eye, a shoulder extending from the grasping eye, and a multiweave mesh grip member extending from the grasping eye, the multiweave mesh grip extending over the core retention clamp, the composite core and the stranded conductor, with at least one clamp configured to clamp the multiweave mesh grip member to the stranded conductor and with at least one clamp configured to clamp the multiweave mesh grip member to the core retention clamp.
13. The combination of claim 12 wherein the at least one clamp configured to clamp the multiweave mesh to the core retention clamp extends over a portion of the core retention clamp that is not crimped to the composite core.
14. The combination of claim 12 further comprising electrical tape extending over the stranded conductor between the multiweave mesh and the stranded conductor.
15. The combination of claim 1 wherein the outer surface of the core retention clamp and the bore are concentric.
16. The combination of claim 1 wherein the crimp defines a polygonal outer surface, and the not crimped portion defines a cylindrical configuration.
17. A method of installation of an electrical conductor having a composite core comprising the steps of:
- providing an electrical conductor having a composite core and a stranded conductor extending therearound, with a portion of the composite core extending beyond the stranded conductor;
- providing a core retention member having a first end and a second end, with, a bore extending therethrough;
- extending the composite core through the bore of the core retention member; and - crimping at least a portion of the core retention member to the composite core.
18. The method of claim 17 wherein the step of extending further comprises the s Lep of stopping the composite core prior to contact with the stranded conductor so that the core retention member is spaced apart from the stranded core.
19. The method of claim 17 wherein the step of crimping further comprises the step of ceasing crimping prior to the second end of the core retention member so that a portion of the core retention member proximate the second end is not crimped to the composite core.
20. The method of claim 17 wherein the step of crimping comprises the step of applying a crimping force with a hydraulic press to the outer surface of the core retention member deforming the outer surface into a polygonal configuration.
21. The method of claim 20 wherein the polygonal configuration comprises a hexagonal configuration.
22. The method of claim 17 wherein the step of crimping further comprises the step of repeatedly crimping the core retention member to the composite core through overlapping crimps.
24. The method of claim 17 further comprising the steps of:
- providing a pulling grip having a multiweave mesh grip member;
- directing the multiweave mesh grip member over the composite core, the core retention member and the stranded conductor;
- first applying at least one clamp to the multiweave mesh grip member to clamp the multiweave mesh grip member to the stranded conductor; and - second applying at least one clamp to the core retention member to clamp the multiweave mesh grip member to the core retention member.
25. The method of claim 24 further comprising the step of applying an electrical tape over the stranded conductor prior to the step of directing the multiweave mesh grip member.
The method of claim 24 wherein for the step of second applying, the at least one clamp extends over a not crimped portion of the core retention member.
- an electrical core having a composite core with a stranded conductor extending therearound, wherein a portion of the composite core extends beyond the stranded conductor;
- a core retention clamp comprising an elongated member haying a first end and a second end and defining an outer surface, with a bore extending from the first end to the second end;
- wherein the core extends through the bore of the core retention clamp such that the second end of the core is positioned proximate the stranded conductor, and wherein at least a portion of the core retention clamp is crimped to the composite core.
2. The combination of claim 1 wherein the composite core comprises a plurality of fibers in a resin matrix.
3. The combination of claim 2 wherein the stranded conductor comprises a plurality of helically wound conductor strands.
4. The combination of claim 3 wherein the conductor strands comprise one of aluminum alloy and anneal ed aluminum.
5. The combination of claim 1 wherein the outer surface of the core retention clamp comprises a cylindrical configuration where not crimped, and a polygonal configuration where crimped.
6. The combination of claim 1 wherein a portion of the core retention clamp proximate the second end remains not crimped.
7. The combination of claim 1 wherein the portion that is crimped is spaced apart from the second end.
8. The combination of claim 7 wherein approximately SO% of the core retention clamp between the first and second end thereof is crimped to the composite core.
9. The combination of claim 1 wherein the second end of the core retention clamp is spaced apart from the stranded conductor.
10. The combination of claim 1 wherein the core retention clamp has a clamp hardness, and wherein the composite core has a core hardness, with the clamp hardness being 60% to 95% the hardness of the composite core, and more preferably between 70% and 90% and more preferably between 75% and 85%.
11. The combination of claim 1 wherein the core retention clamp comprises a Aluminum.
12. The combination of claim 1 further comprising a pulling grip having a grasping eye, a shoulder extending from the grasping eye, and a multiweave mesh grip member extending from the grasping eye, the multiweave mesh grip extending over the core retention clamp, the composite core and the stranded conductor, with at least one clamp configured to clamp the multiweave mesh grip member to the stranded conductor and with at least one clamp configured to clamp the multiweave mesh grip member to the core retention clamp.
13. The combination of claim 12 wherein the at least one clamp configured to clamp the multiweave mesh to the core retention clamp extends over a portion of the core retention clamp that is not crimped to the composite core.
14. The combination of claim 12 further comprising electrical tape extending over the stranded conductor between the multiweave mesh and the stranded conductor.
15. The combination of claim 1 wherein the outer surface of the core retention clamp and the bore are concentric.
16. The combination of claim 1 wherein the crimp defines a polygonal outer surface, and the not crimped portion defines a cylindrical configuration.
17. A method of installation of an electrical conductor having a composite core comprising the steps of:
- providing an electrical conductor having a composite core and a stranded conductor extending therearound, with a portion of the composite core extending beyond the stranded conductor;
- providing a core retention member having a first end and a second end, with, a bore extending therethrough;
- extending the composite core through the bore of the core retention member; and - crimping at least a portion of the core retention member to the composite core.
18. The method of claim 17 wherein the step of extending further comprises the s Lep of stopping the composite core prior to contact with the stranded conductor so that the core retention member is spaced apart from the stranded core.
19. The method of claim 17 wherein the step of crimping further comprises the step of ceasing crimping prior to the second end of the core retention member so that a portion of the core retention member proximate the second end is not crimped to the composite core.
20. The method of claim 17 wherein the step of crimping comprises the step of applying a crimping force with a hydraulic press to the outer surface of the core retention member deforming the outer surface into a polygonal configuration.
21. The method of claim 20 wherein the polygonal configuration comprises a hexagonal configuration.
22. The method of claim 17 wherein the step of crimping further comprises the step of repeatedly crimping the core retention member to the composite core through overlapping crimps.
24. The method of claim 17 further comprising the steps of:
- providing a pulling grip having a multiweave mesh grip member;
- directing the multiweave mesh grip member over the composite core, the core retention member and the stranded conductor;
- first applying at least one clamp to the multiweave mesh grip member to clamp the multiweave mesh grip member to the stranded conductor; and - second applying at least one clamp to the core retention member to clamp the multiweave mesh grip member to the core retention member.
25. The method of claim 24 further comprising the step of applying an electrical tape over the stranded conductor prior to the step of directing the multiweave mesh grip member.
The method of claim 24 wherein for the step of second applying, the at least one clamp extends over a not crimped portion of the core retention member.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US202063019285P | 2020-05-02 | 2020-05-02 | |
| US63/019,285 | 2020-05-02 | ||
| PCT/US2021/030526 WO2021225992A1 (en) | 2020-05-02 | 2021-05-03 | Core retention compression clamp and method of installation |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA3177702A1 true CA3177702A1 (en) | 2021-11-11 |
Family
ID=78468299
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA3177702A Pending CA3177702A1 (en) | 2020-05-02 | 2021-05-03 | Core retention compression clamp and method of installation |
Country Status (3)
| Country | Link |
|---|---|
| CA (1) | CA3177702A1 (en) |
| MX (1) | MX2022013853A (en) |
| WO (1) | WO2021225992A1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11854721B2 (en) | 2022-03-28 | 2023-12-26 | Ts Conductor Corp. | Composite conductors including radiative and/or hard coatings and methods of manufacture thereof |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2008100632A2 (en) * | 2007-02-15 | 2008-08-21 | Advanced Technology Holdings Ltd | Electrical conductor and core for an electrical conductor |
| JP2014064402A (en) * | 2012-09-21 | 2014-04-10 | 3M Innovative Properties Co | Coating treatment tool and coating treatment method of cable connection part |
| CN105870863B (en) * | 2016-05-19 | 2017-11-07 | 凤凰电力有限公司 | Carbon fiber complex core strain clamp |
-
2021
- 2021-05-03 CA CA3177702A patent/CA3177702A1/en active Pending
- 2021-05-03 MX MX2022013853A patent/MX2022013853A/en unknown
- 2021-05-03 WO PCT/US2021/030526 patent/WO2021225992A1/en active Application Filing
Also Published As
| Publication number | Publication date |
|---|---|
| MX2022013853A (en) | 2023-06-28 |
| WO2021225992A1 (en) | 2021-11-11 |
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