This invention relates generally to electrical connectors, and more particularly, to power utility connectors for mechanically and electrically connecting a tap or distribution conductor to a main electrical transmission conductor.
Electrical utility firms constructing, operating and maintaining overhead and/or underground power distribution networks and systems utilize connectors to tap main power transmission conductors and feed electrical power to distribution line conductors, sometimes referred to as tap conductors. The main power line conductors and the tap conductors are typically high voltage cables that are relatively large in diameter, and the main power line conductor may be differently sized from the tap conductor, requiring specially designed connector components to adequately connect tap conductors to main power line conductors. Generally speaking, three types of connectors are commonly used for such purposes, namely bolt-on connectors, compression-type connectors, and wedge connectors.
Bolt-on connectors typically employ die-cast metal connector pieces or connector halves formed as mirror images of one another, sometimes referred to as clam shell connectors. Each of the connector halves defines opposing channels that axially receive the main power conductor and the tap conductor, respectively, and the connector halves are bolted to one another to clamp the metal connector pieces to the conductors. Such bolt-on connectors have been widely accepted in the industry primarily due to their ease of installation, but such connectors are not without disadvantages. For example, proper installation of such connectors is often dependent upon predetermined torque requirements of the bolt connection to achieve adequate connectivity of the main and tap conductors. Applied torque in tightening the bolted connection generates tensile force in the bolt that, in turn, creates normal force on the conductors between the connector halves. Applicable torque requirements, however, may or may not be actually achieved in the field and even if the bolt is properly tightened to the proper torque requirements initially, over time, and because of relative movement of the conductors relative to the connector pieces or compressible deformation of the cables and/or the connector pieces over time, the effective clamping force may be considerably reduced. Additionally, the force produced in the bolt is dependent upon frictional forces in the threads of the bolt, which may vary considerably and lead to inconsistent application of force among different connectors.
Compression connectors, instead of utilizing separate connector pieces, may include a single metal piece connector that is bent or deformed around the main power conductor and the tap conductor to clamp them to one another. Such compression connectors are generally available at a lower cost than bolt-on connectors, but are more difficult to install. Hand tools are often utilized to bend the connector around the cables, and because the quality of the connection is dependent upon the relative strength and skill of the installer, widely varying quality of connections may result. Poorly installed or improperly installed compression connectors can present reliability issues in power distribution systems.
Wedge connectors are also known that include a C-shaped channel member that hooks over the main power conductor and the tap conductor, and a wedge member having channels in its opposing sides is driven through the C-shaped member, deflecting the ends of the C-shaped member and clamping the conductors between the channels in the wedge member and the ends of the C-shaped member. One such wedge connector is commercially available from Tyco Electronics Corporation of Harrisburg, Pa. and is known as an AMPACT Tap or Stirrup Connector. AMPACT connectors, however, tend to be more expensive than either bolt-on or compression connectors, and special application tooling, using explosive cartridges packed with gunpowder, has been developed to drive the wedge member into the C-shaped member. Different connectors and tools are available for various sizes of conductors in the field.
AMPACT connectors are believed to provide superior performance over bolt-on and compression connectors. For example, the AMPACT connector results in a wiping contact surface that, unlike bolt-on and compression connectors, is stable, repeatable, and consistently applied to the conductors, and the quality of the mechanical and electrical connection is not as dependent on torque requirements and/or relative skill of the installer. Additionally, and unlike bolt-on or compression connectors, because of the deflection of the ends of the C-shaped member some elastic range is present wherein the ends of the C-shaped member may spring back and compensate for relative compressible deformation or movement of the conductors with respect to the wedge and/or the C-shaped member.
It would be desirable to provide a lower cost, more universally applicable alternative to conventional wedge connectors that provides superior connection performance to bolt-on and compression connectors.
According to an exemplary embodiment, an electrical connector assembly is provided including a first conductive member having a first hook portion extending from a first base wedge portion and adapted to engage a first conductor, and a second conductive member having a second hook portion extending from a second wedge portion and adapted to engage a second conductor. The first wedge portion and the second wedge portion are adapted to nest with one another and be secured to one another. Each of the first and second conductive members includes a visual alignment indicator to define a final mating relation between the first and second conductive members once fully mated.
Optionally, at least one of the visual alignment indicators may include a groove formed in the respective one of the first and second wedge portions. The visual alignment indicators may define a final mating relation between the first and second conductive members once the first and second conductive members are fully mated. Each wedge portion may include a contact face engaging one another when the wedge portions are nested with one another, wherein the visual alignment indicators extend from a respective one of the contact faces. The visual alignment indicators may be linear and aligned with one another to define the final mating relation. Optionally, each wedge portion may include an abutment face, a wiping contact surface angled with respect to the abutment face, and a conductor contact surface extending substantially perpendicular to the abutment face, wherein each visual alignment indicator extends from a respective one of the wiping contact faces toward a respective one of the conductor contact faces.
According to another exemplary embodiment, an electrical connector assembly is provided for power utility transmission conductors. The assembly includes a first conductive member and a second conductive member separately fabricated from one another and cooperating to interconnect first and second conductors. Each of the first and second conductive member include a wedge portion and a deflectable channel portion extending from the wedge portion, wherein the wedge portion of the first conductive member has a first visual alignment indicator and the wedge portion of the second conductive member has a second visual alignment indicator. The wedge portion of the first conductive member is configured to nest within and be secured to the wedge portion of the second conductive member, and the wedge portion of the second conductive member is configured to nest within and be secured to the wedge portion of the first conductive member. A fastener extends through the wedge portion of each of the first and second conductive members, wherein the fastener is configured to fully join the first and second conductive members to one another. The first and second visual alignment indicators are aligned with one another to indicate when the first and second conductive members are fully joined to one another.
According to a further exemplary embodiment, an electrical connector assembly is provided for power utility transmission. The assembly includes a first conductive member and a second conductive member separately fabricated from one another. Each of the first and second conductive members includes a wedge portion and a deflectable channel portion extending from the wedge portion, wherein the wedge portion of the first conductive member has a first visual alignment indicator and the wedge portion of the second conductive member has a second visual alignment indicator. The channel portion of the first conductive member is configured for receiving a main power line conductor at a spaced location from the wedge portion of the first conductive member. The channel portion of the second conductive member is configured for receiving a tap line conductor at a spaced location from the wedge portion of the second conductive member. A fastener joins the wedge portions of the first and second conductive members to one another until the visual alignment indicators are substantially aligned with one another.
The wedge member 56 may be installed with special tooling having for example, gunpowder packed cartridges, and as the wedge member 56 is forced into the C-shaped member 54, the ends of the C-shaped member are deflected outwardly and away from one another via the applied force FA shown in
I=HW+D1+D2−HC (1)
With strategic selection of HW and HC the actual interference I achieved may be varied for different diameters D1 and D2 of the conductors 52 and 55. Alternatively, HW and Hc may be selected to produce a desired amount of interference I for various diameters D1 and D2 of the conductors 52 and 55. Consistent generation of at least a minimum amount of interference I results in a consistent application of applied force FA which will now be explained in relation to
The tap conductor 102, sometimes referred to as a distribution conductor, may be a known high voltage cable or line having a generally cylindrical form in an exemplary embodiment. The main conductor 104 may also be a generally cylindrical high voltage cable line. The tap conductor 102 and the main conductor 104 may be of the same wire gage or different wire gage in different applications and the connector assembly 100 is adapted to accommodate a range of wire gages for each of the tap conductor 102 and the main conductor 104.
When installed to the tap conductor 102 and the main conductor 104, the connector assembly 100 provides electrical connectivity between the main conductor 104 and the tap conductor 102 to feed electrical power from the main conductor 104 to the tap conductor 102 in, for example, an electrical utility power distribution system. The power distribution system may include a number of main conductors 104 of the same or different wire gage, and a number of tap conductors 102 of the same or different wire gage. The connector assembly 100 may be used to provide tap connections between main conductors 104 and tap conductors 102 in the manner explained below.
As shown in
The tap conductive member 106 includes a wedge portion 110 and a channel portion 112 extending from the wedge portion 110. A fastener bore 114 is formed in and extends through the wedge portion 110, and the wedge portion 110 further includes an abutment face 116, a wiping contact surface 118 angled with respect to the abutment face 116, and a conductor contact surface 120 extending substantially perpendicular to the abutment face 116 and obliquely with respect to the wiping contact surface 118.
The channel portion 112 extends away from the wedge portion 110 and forms a channel or cradle 119 adapted to receive the tap conductor 102 at a spaced relation from the wedge portion 110. A distal end 122 of the channel portion 112 includes a radial bend that wraps around the tap conductor 102 for about 180 circumferential degrees in an exemplary embodiment, such that the distal end 122 faces toward the wedge portion 110, and the wedge portion 110 overhangs the channel or cradle 119. The channel portion 112 is reminiscent of a hook in one embodiment, and the wedge portion 110 and the channel portion 112 together resemble the shape of an inverted question mark. The tap conductive member 106 may be integrally formed and fabricated from extruded metal, together with the wedge and channel portions 110, 112 in a relatively straightforward and low cost manner.
The main conductive member 107 likewise includes a wedge portion 124 and a channel portion 126 extending from the wedge portion 124. A fastener bore 128 is formed in and extends through the wedge portion 124, and the wedge portion 124 further includes an abutment face 130, a wiping contact surface 132 angled with respect to the abutment face 130, and a conductor contact surface 134 extending substantially perpendicular to the abutment face 130 and obliquely with respect to the wiping contact surface 132. In one embodiment, an inner diameter of the fastener bore 128 is larger than an outer diameter of the fastener 108, thereby providing some relative freedom of movement of the fastener 108 with respect to the fastener bore 128 as the conductive members 106 and 107 are mated as explained below.
The channel portion 126 extends away from the wedge portion 124 and forms a channel or cradle 136 adapted to receive the main conductor 104 at a spaced relation from the wedge portion 124. A distal end 138 of the channel portion 126 includes a radial bend that wraps around the main conductor 104 for about 180 circumferential degrees in an exemplary embodiment, such that the distal end 138 faces toward the wedge portion 124, and the channel 136 overhangs the wedge portion 124. The channel portion 126 is reminiscent of a hook in one embodiment, and the wedge portion 124 and the channel portion 126 together resemble the shape of a question mark. The main conductive member 107 may be integrally formed and fabricated from extruded metal, together with the wedge and channel portions 124, 126 in a relatively straightforward and low cost manner.
The tap conductive member 106 and the main conductive member 107 are separately fabricated from one another or otherwise formed into discrete connector components and are assembled to one another as explained below. While one exemplary shape of the tap and main conductive members 106, 107 has been described herein, it is recognized that the conductive members 106, 107 may be alternatively shaped in other embodiments as desired.
In an exemplary embodiment, the tap conductive member 106 includes a first visual alignment indicator 140 and the main conductive member 106 includes a second visual alignment indicator 142. The first and second visual alignment indicators 140, 142 cooperate to visually define a final mating position of the tap and main conductive members 106, 107 as the tap and main conductive members 106, 107 are mated. During assembly of the connector assembly 100, the visual alignment indicators 140, 142 are used by the installer to determine a relative position of the tap conductive member 106 with respect to the main conductive member 107. The fastener 108 is tightened until the visual alignment indicators 140, 142 are positioned at predetermined locations with respect to one another. In an exemplary embodiment, the fastener 108 is tightened until the visual alignment indicators 140, 142 are substantially aligned with one another. As such, the visual alignment indicators 140, 142 are used to define a final mating position of the tap and main conductive members 106, 107 independent of an amount of force induced upon the main and tap conductors 104 and 102 by the main and tap conductive members 107 and 106.
The first and second visual alignment indicators 140, 142 are exposed on at least one side 144 of each of the tap and main conductive members 106, 107. As such, the relative positions of the visual alignment indicators 140, 142 may be seen by the installer during assembly. Optionally, as illustrated in
In the illustrated embodiment, each visual alignment indicator 140, 142 includes a groove 146 formed in the respective wedge portions 110 and 124. Each groove 146 extends from the respective wiping contact surface 118, 132. Optionally, each groove 146 extends substantially perpendicular from the wiping contact surface 118, 132, however, the grooves 146 may extend non-perpendicularly in alternative embodiments. In an exemplary embodiment, the grooves 146 are rectangular in shape and are formed by cutting or otherwise removing a portion of the tap or main conductive member 106, 107. Alternatively, the grooves 146 may have alternative shapes, and the grooves 146 may be formed, such as by a molding or forming operation during manufacture of the tap and main conductive members 106, 107.
The grooves 146 have a depth 148 measured from the respective wiping contact surface 118, 132 and a width 150 measured from the respective side 144. The depth 148 is selected to provide adequate visual indication of the relative positions of the grooves 146 with respect to one another during assembly of the connector assembly 100. The structural integrity of the wedge portion 110 or 124 may be taken into consideration in determining the depth 148. In the illustrated embodiment, the depth 148 is approximately 40% of the distance between the wiping contact surface 118 or 132 and the conductor contact surface 120 or 134. The depth 148 may be more or less than 40% in alternative embodiments. In the illustrated embodiment, the width 150 is approximately equal to the depth 148, however, the width may be varied in alternative embodiments.
In an alternative embodiment, the groove may be 100% of the width of the wedge portion 110, 124 and extend completely across the wiping contact surface 118, 132. In another alternative embodiment, the width 150 may be minimal, such as approximately 1% of the width of the wedge portion 110 or 124 such that the visual alignment indicators 140, 142 are merely marks on the sides 144 of the wedge portions 110, 124. In a further alternative embodiment, rather than a groove 144 having a width 150, a mark may be made on the side 144, such as by using paint or ink, or by changing a visual appearance of the material used for the conductive members 106, 107, such as scorching or blazing the side 144. Alternatively, a component may be added to the side 144 to represent the visual alignment indicators 140, 142. For example, a component may be welded or soldered to the side 144, a component may be adhered to the side 144, or a component may be otherwise fastened to the side 144. Other alternative types of visual alignment indicators may be used as well.
In one embodiment, the wedge portions 110 and 124 of the respective tap and the main conductive members 106, 107 are substantially identically formed and share the same geometric profile and dimensions to facilitate interfitting of the wedge portions 110 and 124 in the manner explained below as the conductive members 106, 107 are mated. The channel portions 112, 126 of the conductive members 106 and 107, however, may be differently dimensioned as appropriate to be engaged to differently sized conductors 102, 104 while maintaining substantially the same shape of the conductive members 106, 107. Identical formation of the wedge portions 110 and 124 provides for mixing and matching of conductive members 106 and 107 for differently sized conductors 102, 104 while achieving a repeatable and reliable connecting interface via the wedge portions 110 and 124.
As shown in
When the channel portions 112, 126 are hooked over the respective conductors 102, 104 and when the conductive member 106, 107 are coupled together by the fastener elements 108, 109, 111, the abutment faces 116, 130 are aligned in an unmated condition as shown in perspective view in
As illustrated in
In the final position, the fastener 108 extends obliquely to each of the fastener bores 114, 128, and the nut 109 may be tightened to the fastener 108 to secure the conductive members 106, 107 to one another. Additionally, in the final position shown in
Movement of the conductor contact surfaces 120, 134 in the opposite directions of arrows A and B clamps the conductors 102 and 104 between the wedge portions 110 and 124, and the opposing channel portions 112, 126. The distal ends 122, 138 of the channel portions 112, 126 are brought adjacent to the wedge portions 110, 124 to the mated position shown in
In the fully mated position shown in
When fully mated, the abutment faces 116 and 130 may engage the channel portions 126 and 112 to form a displacement stop that defines and limits a final displacement relation between the tap and main conductive members 106 and 107. The displacement stop defines a final mating position between the tap and main conductive members 106 and 107 independent of an amount of force induced upon the main and tap conductors 104 and 102 by the main and tap conductive members 107 and 106. In such an embodiment, the first and second visual alignment indicators 140, 142 may provide a visual indication to the installer that the conductive members 106, 107 are in the final mating position and that the abutment faces 116 and 130 are engaged to the channel portions 126 and 112. In an alternative embodiment, the abutment faces 116 and 130 may be positioned a distance from the channel portions 126 and 112 in the final mating position.
Optionally, the displacement stop may be created from a stand off provided on one or both of the main and tap conductive members 107 and 106. For example, the stand off may be positioned proximate the fastener bore 128 and extend outward therefrom. Alternatively, the stand off may be created as mating notches provided in the wiping contact surfaces 118 and 132, where the notches engage one another to limit a range of travel of the main and tap conductive members 107 and 106 toward one another.
Likewise, the wedge portion 124 of the main conductive member 107 clamps the tap conductor 102 against the channel portion 112 of tap conductive member 106 and the channel portion 112 is deflected in the direction of arrow G. The channel portion 112 to is elastically and plastically deflected in a radial direction indicated by arrow G, resulting in a spring back force in the direction of Arrow H opposite to the direction of arrow G. A large contact force, on the order of about 4000 lbs is provided in an exemplary embodiment, and the clamping force ensures adequate electrical connectivity between the tap conductor 102 and the connector assembly 100. Additionally, elastic spring back of the channel portion 112 provides some tolerance for deformation or compressibility of the tap conductor 102 over time, because the channel portion 112 may simply return in the direction of arrow H if the tap conductor 102 deforms due to compression forces. Actual clamping forces may be lessened in such a condition, but not to such an amount as to compromise the integrity of the electrical connection. In an exemplary embodiment, the first and second visual alignment indicators 140, 142 allow a range of tolerance within the elastic range of the channel portion 112.
Unlike known bolt connectors, torque requirements for tightening of the fastener 108 are not required to satisfactorily install the connector assembly 100. The first and second visual alignment indicators 140, 142 indicate to the installer when the conductive members 106, 107 are fully mated. The visual alignment indicators 140, 142 allows the nut 109 and fastener 108 to be continuously tightened until the visual alignment indicators 140, 142 are properly oriented, independent of, and without regard for, any normal forces created by the tap and main conductors 102 and 104. In the fully mated condition, the interference between the conductors 102 and 104 and the connector assembly 100 produces a contact force adequate to provide a good electrical connection. The contact forces are created by interference between the channel portions 126, 112, and wedge portions 110, 124, and tap and main conductors 102 and 104. It is not necessary to measure the bolt torque in the mating the connector assembly 100 as the connector assembly 100 is fully mated when the visual alignment indicators 140, 142 are properly oriented. By virtue of the fastener elements 108 and 109 and the combined wedge action of the wedge portions 110, 124 to deflect the channel portions 112 and 126, the connector assembly 100 may be installed with hand tools, and specialized tooling, such as the explosive cartridge tooling of the AMPACT Connector system is avoided.
Optionally, when the abutment faces 116, 130 of the wedge portions 110, 124 contact the channel portions 126 and 112, the connector assembly 100 is fully mated. The displacement stop allows the nut 109 and fastener 108 to be continuously tightened until the abutment faces 116 and 130 fully seat against the channel portions 126 and 112, independent of, and without regard for, any normal forces created by the tap and main conductors 102 and 104.
It is recognized that effective clamping force on the conductors 102, 104 is dependent upon the geometry of the wedge portions, dimensions of the channel portions, and size of the conductors used with the connector assembly 100. Thus, with strategic selections of the positions of the visual alignment indicators 140, 142, the angles for the wiping contact surfaces 118, 130, and the radius and thickness of the curved distal ends 122 and 138 of the conductive members, varying degrees of clamping force may be realized when the conductive members 106 and 107 are used in combination as described above.
The visual alignment indicators 160, 162 are represented by markings 160, 162 placed on the sides 144 of the conductive members 106, 107 rather than grooves formed in the conductive members 106, 107 as in the embodiments illustrated in
As shown in
I=HW+DC−HCL (2)
By strategically selecting HW and HCL, repeatable and reliable performance may be provided in a similar manner as explained above in relation to
Because of the deflectable channel portions 112, 126 in discrete connector components, the conductive members 106 and 107 may accommodate a greater range of conductor sizes or gages in comparison to conventional wedge connectors. Additionally, even if several versions of the conductive members 106 and 107 are provided for installation to different conductor wire sizes or gages, the assembly 100 requires a smaller inventory of parts in comparison to conventional wedge connector systems, for example, to accommodate a full range of installations in the field. That is, a relatively small family of connector parts having similarly sized and shaped wedge portions may effectively replace a much larger family of parts known to conventional wedge connector systems.
It is therefore believed that the connector assembly 100 provides the performance of conventional wedge connector systems in a lower cost connector assembly that does not require specialized tooling and a large inventory of parts to meet installation needs. Using low cost extrusion fabrication processes and known fasteners, the connector assembly 100 may be provided at low cost, while providing increased repeatability and reliability as the connector assembly 100 is installed and used. The combination wedge action of the conductive members 106 and 107 provides a reliable and consistent clamping force on the conductors 102 and 104 and is less subject to variability of clamping force when installed than either of known bolt-on or compression-type connector systems.
Each of the conductive members 206 and 207 are formed with respective wedge portions 210 and 212, and each of the wedge portions 210 and 212 defines a wiping contact surface 214, 216 and a conductor contact surface 217, 218. Optionally, and as shown in
Additionally, in the assembly 200, the wedge portions 210 and 212 are geometrically shaped so that fastener bores 220, 222 formed through the respective wedges more readily align with the fastener 208 than in the connector assembly 100, thereby reducing, if not limiting, the tendency of the fastener 208 to float and pivot relative to the conductive members 206, 207 as the assembly 200 is installed to the conductors. This construction is believed to permit complete engagement of the conductive members 206, 207 with a reduced amount of force applied to the fastener 208.
It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-described embodiments (and/or aspects thereof) may be used in combination with each other. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Dimensions, types of materials, orientations of the various components, and the number and positions of the various components described herein are intended to define parameters of certain embodiments, and are by no means limiting and are merely exemplary embodiments. Many other embodiments and modifications within the spirit and scope of the claims will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects. Further, the limitations of the following claims are not written in means—plus-function format and are not intended to be interpreted based on 35 U.S.C. § 112, sixth paragraph, unless and until such claim limitations expressly use the phrase “means for” followed by a statement of function void of further structure.
This application is a continuation-in-part of U.S. application Ser. No. 11/437,480, filed May 18, 2006, and entitled “Combination Wedge Tap Connector”, which is hereby incorporated by reference in its entirety.
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Number | Date | Country | |
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Parent | 11437480 | May 2006 | US |
Child | 11804065 | US |