The present disclosure relates generally to electrical utility lines, and further relates to vibration dampers utilized upon electrical utility lines (e.g., electrical power lines).
Dampers for electrical utility lines respond to wind induced line vibration and help to dissipate vibration energy of oscillations. In particular, there may be interest to dampen line vibration that may be characterized by high frequency, low amplitude motion, e.g., aeolian vibration. Such dampers are placed upon the suspended, extending electrical lines.
There are various types of dampers. One example type of damper is a Stockbridge damper, which is generally comprises a short length of cable/rod that is clamped parallel to electrical utility line, with masses fixed at each end of the short cable/rod. Often, a damper, such as a Stockbridge damper, is clamped directly to electrical conducting material, e.g., the conductor, of the electrical utility line.
Some electrical utility lines include an electrically insulating sheathing material that covers the conductor of the electrical utility line. There may be several reasons for utilizing an electrical utility line that includes an electrically insulating sheathing material (e.g., plastic) that covers the conductor. For example, locations that may have vegetation that may contact an electrical utility line may be location selected to use an electrical utility line that includes an electrically insulating sheathing material that covers the conductor.
This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key factors or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
According to an aspect, a vibration damper for damping vibrations of a cable includes an attachment portion configured to be attached to the cable. The attachment portion has an inner surface defining an opening whereby a hot stick placed in the opening. While in the opening, the hot stick can contact the inner surface to urge the attachment portion into contact with the cable while the cable is energized. The vibration damper also includes a flexible leg portion attached to the attachment portion. The vibration damper further includes a weighted portion attached to the flexible leg portion. The weighted portion is spaced a separation distance from the attachment portion and the weighted portion is movable relative to the attachment portion via the flexible leg portion to dampen the vibrations.
According to an aspect, a vibration damper for damping vibrations of a cable includes an attachment portion configured to be attached to the cable. The attachment portion has a first structure. The vibration damper also includes a keeper attached to the attachment portion. The keeper is movable from an open position to a closed position to facilitate attaching the attachment portion to the cable. The keeper has a second structure configured to cooperate with the first structure to maintain the keeper in a desired orientation relative to the attachment portion as the keeper moves from the open position to the closed position. The vibration damper further includes a flexible leg portion attached to the attachment portion. The vibration damper still further includes a weighted portion attached to the flexible leg portion, the weighted portion spaced a separation distance from the attachment portion and movable relative to the attachment portion via the flexible leg portion to dampen the vibrations.
According to an aspect, a vibration damper for damping vibrations of a cable includes an attachment portion configured to be attached to the cable. The attachment portion has a cable contact surface extending from a first end to a second end. The cable contact surface has a concave shape between the first end and the second end such that the cable contact surface is positioned on each of a first side of the cable, a top side of the cable, and a second side of the cable when the attachment portion is attached to the cable. The vibration damper also includes a flexible leg portion attached to the attachment portion. The vibration damper further includes a weighted portion attached to the flexible leg portion. The weighted portion is spaced a separation distance from the attachment portion and the weighted portion is movable relative to the attachment portion via the flexible leg portion to dampen the vibrations.
The following description and annexed drawings set forth certain illustrative aspects and implementations. These are indicative of but a few of the various ways in which one or more aspects may be employed. Other aspects, advantages, and/or novel features of the disclosure will become apparent from the following detailed description when considered in conjunction with the annexed drawings.
The claimed subject matter is now described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide an understanding of the claimed subject matter. It is evident, however, that the claimed subject matter may be practiced without these specific details. In other instances, structures and devices are illustrated in block diagram form in order to facilitate describing the claimed subject matter. Relative size, orientation, etc. of parts, components, etc. may differ from that which is illustrated while not falling outside of the scope of the claimed subject matter.
Climate at some locations, e.g., in the state of California and surrounding areas, may be prone to promotion of wildfires. It has been found recently that vegetation has come into contact with exposed and degraded power distribution systems, thereby causing wildfires. To mitigate the risk and likelihood of these occurrences, multiple power utility providers have begun installing multi-layered, plastic-jacketed conductors (“covered conductors”) throughout their systems.
Within some examples, the plastic-jacketed conductors (“covered conductors”) may be compliant with UL-94 specification. UL-94 details testing and standards for the flammability of plastic materials. Accordingly, the examples of plastic-jacket specify material must conform to V-0 requirements per UL-94. In general, the requirement includes that the material must self-extinguish (e.g., not promote flame spread) and produce no flaming “drips” of material that would ignite flammable or combustible materials below the covered conductors.
With these new conductors, new hardware, improved hardware, etc. is needed as the plastic jacket can act very differently than examples of bare conductor (e.g., bare stranding) conductors that have been frequently in use. One example type of hardware that may benefit from modifications is the vibration damper such as a Stockbridge vibration damper.
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The damper system 100 comprises a vibration damper 104. In an example, the vibration damper 104 can be attached to (e.g., suspended from) the cable 102 by an attachment structure 106. The attachment structure 106 may include a hook, clamping mechanism, or other types of mechanical fasteners that function to attach the vibration damper 104 to the cable 102. In this way, the vibration damper 104 may be secured to the cable 102 and limited from being inadvertently detached and/or separated from the cable 102. As will be described herein, the vibration damper 104 can reduce and/or attenuate vibrations that are experienced by the cable 102. In more common examples, the vibration damper 104 is hanging beneath the cable 102 such that gravity is acting in a downward direction 108 in
In at least some previous applications, a vibration damper having a clamp and a keeper are bolted directly to the cable. However, for a covered conductor or covered cable, research has shown that damage to the outer jacketing of the cable may occur. It is possible that damage may rise to an unacceptable extent such that the clamp may lose a significant portion of its application torque or application force. Such undesired effects may allow a vibration damper clamp to loosen and potentially fall from the cable.
It is to be appreciated that a known one-piece clamp design attaches to the conductor via helical steel rods coated in a flame-retardant TPU. These dampers are easy, though time-consuming, to install by hand but are very difficult to install via “hot-stick” (necessary when the line is already energized).
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The upper end 304 of the attachment portion 302 can include an inner surface 308 defining an opening 310. A hot stick (shown in
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In some examples, the attachment portion 302 can include a first structure 314. Forms of the first structure 314 can vary, however, in the shown example, the first structure 314 is a platform-like volume raised away from the first side 300 of the attachment portion 302. In some examples, the attachment portion 302 can also include a second platform-like volume 316 formed away from the opposite side of the attachment portion 302. This combination of the first structure 314 and the second platform-like volume 316 can define an interior wall bounding a cylindrical volume designed to accept a part of a keeper 318 to help attach the keeper 318 to the attachment portion 302. As shown, a second structure 320 such as a cylindrical-shaped extension of the keeper 318 can cooperate with the first structure 314 of the attachment portion 302. This cooperation can limit the degrees of freedom of the keeper 318 while moving relative to the attachment portion 302. In some examples, the second structure 320 is configured to cooperate with the first structure 314 to maintain the keeper 318 in a desired orientation relative to the attachment portion 312 as the keeper 318 moves from an open position to a closed position which will be described below.
In some examples, a resilient material 322 is attached to at least one of the attachment portion 302 or the keeper 318 to avoid possible damage to the cable 102. The resilient material 322 can include rubber compounds or other, similar materials that are relatively pliable in comparison to materials used for the attachment portion 302, the attachment structure 106, and the keeper 318. The resilient material 322 can at least one of eliminate or reduce deformation to the plastic jacket 202 of the cable 102. In this way, the resilient material 322 can mitigate damage to the cable 102. The resilient material 322 can be attached to either one or both of the attachment portion 302 or the keeper 318 using an adhesive or any suitable attachment method. Furthermore, the resilient material 322 can include a concave face that cooperates with the convex exterior surface of the plastic jacket 202 of the cable 102.
A fastener 324 is also shown which helps attach the keeper 318 to the attachment portion 302. In some examples, the fastener 324 is a hex-head screw that can urge the keeper 318 toward the attachment portion 302 in a rotational motion as the keeper 318 rotates about an axis of the second structure 320. Of course, the fastener 324 can include any number of suitable fasteners and is not to be limited by the shown example.
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Any suitable attachment structure or method of attachment can be used in conjunction with the present disclosure. In some examples, the attachment portion 302 is crimped around the flexible leg portion 506 to attach the flexible leg portion 506 to the attachment portion 302. In some examples, the flexible leg portion 506 extend through the attachment portion 302 such that the flexible leg portion 506 is continuous from the first attachment side 502 to the second attachment side 504.
The flexible leg portion 506 can be constructed in any suitable manner with various materials. The flexible leg portions 506 can comprise any number of materials, such as a braided wire, cable, or the like. In some examples, the flexible leg portion 506 may have at least some degree of flexibility and/or spring factor, such that the flexible leg portion 506 can bend, flex, and/or otherwise move in response to vibration forces. In the shown examples, the flexible leg portion 506 consists of individual strands that can be cabled or helically wound together. In some examples, the strands comprise a relatively rigid material that provides at least some degree of rigidity, inflexibility, strength, support, etc. In some examples, the strands can include a metal material.
In some examples, the flexible leg portion 506 can be known as a messenger or a messenger wire. The flexible leg portion 506 can include two or more layers of helically wound strands of high tensile steel wire. In some examples, the flexible leg portion 506 can be made of formed hard steel wires that are galvanized for corrosion resistance. However, the flexible leg portion 506 and can also be coated with a mischmetal coating or a bezinal coating as opposed to galvanization. It is to be understood that any suitable material is contemplated for the purposes of this disclosure.
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Similarly, a second weighted portion 518 is attached to the second portion 512 of the flexible leg portion 506. The second weighted portion 518 is spaced a second separation distance 520 from the second attachment side 504 of the attachment portion 302.
It is to be appreciated that the vibration damper 104 can be engineered and constructed in order to achieve desired attenuation or damping of the vibrations experienced by the cable 102. Some variables leading to effective damping can include a mass of the weighted portion 514 and a mass of the second weighted portion 518. Additionally, the separation distance 516 and the second separation distance 520 are also variables affecting the damping effectiveness. As such, there are examples of the described vibration damper 104 where the separation distance 516 and the second separation distance 520 are not equal. Furthermore, the size and geometry of the weighted portion 514 determining the mass of the weighted portion 514 are not the same as the size and geometry of the second weighted portion 518. These variables and others such as the spring factor of the flexible leg portion 506 can be engineered in innumerable combinations to achieve the desired damping effects.
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It can be beneficial to attach the weighted portion 514 and the second weighted portion 518 securely to the ends of the flexible leg portion 506 and this is conventionally done in any number of ways. The flexible leg portion 506 can be secured within the weighted portion 514 and the second weighted portion 518 by a staking ball. Specifically, a messenger hole can be drilled (or pre-cast) in the forked side of the weighted portion 514 and the second weighted portion 518. The openings 706 are sized to accept any diameter of the flexible leg portion 506. In some examples, the flexible leg portion 506 can be between 5 mm and 10 mm in diameter, but can be any diameter for transmitting vibrations.
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Although the subject matter has been described in language specific to structural features or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing at least some of the claims.
Various operations of embodiments are provided herein. The order in which some or all of the operations described should not be construed to imply that these operations are necessarily order dependent. Alternative ordering will be appreciated having the benefit of this description. Further, it will be understood that not all operations are necessarily present in each embodiment provided herein. Also, it will be understood that not all operations are necessary in some embodiments.
Many modifications may be made to the instant disclosure without departing from the scope or spirit of the claimed subject matter. Unless specified otherwise, “first,” “second,” or the like are not intended to imply a temporal aspect, a spatial aspect, an ordering, etc. Rather, such terms are merely used as identifiers, names, etc. for features, elements, items, etc. For example, a first component and a second component correspond to component A and component B or two different or two identical components or the same component.
Moreover, “exemplary” is used herein to mean serving as an example, instance, illustration, etc., and not necessarily as advantageous. As used in this application, “or” is intended to mean an inclusive “or” rather than an exclusive “or”. In addition, “a” and “an” as used in this application are to be construed to mean “one or more” unless specified otherwise or clear from context to be directed to a singular form. Also, at least one of A and B or the like means A or B or both A and B. Furthermore, to the extent that “includes”, “having”, “has”, “with”, or variants thereof are used in either the detailed description or the claims, such terms are intended to be inclusive in a manner similar to “comprising”.
Also, although the disclosure has been illustrated and described with respect to one or more implementations, equivalent alterations and modifications will occur to others skilled in the art based upon a reading and understanding of this specification and the annexed drawings. The disclosure includes all such modifications and alterations and is limited only by the scope of the following claims. In particular regard to the various functions performed by the above described components (e.g., elements, resources, etc.), the terms used to describe such components are intended to correspond, unless otherwise indicated, to any component which performs the specified function of the described component (e.g., that is functionally equivalent), even though not structurally equivalent to the disclosed structure. In addition, while a particular feature of the disclosure may have been disclosed with respect to only one of several implementations, such feature may be combined with one or more other features of the other implementations as may be desired and advantageous for any given or particular application.
This application claims priority to U.S. Provisional Patent Application No. 63/316,357, filed on Mar. 3, 2022, entitled “HOTLINE CLAMP FOR COVERED CONDUCTORS,” which is hereby incorporated by reference herein.
Number | Date | Country | |
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63316357 | Mar 2022 | US |