The invention relates generally to overhead and underground power distribution equipment and, more particularly, to a pole mount cable restraint insulator.
Electric utility companies use cable restraint insulators to mount power lines, such as medium voltage cables (for example, 5 kV to 35 kV), to riser poles and to bus bars in underground vaults or substations. These insulators typically feature two parts: 1) a clamp portion to secure the cables to the insulator and 2) a mount portion to secure the insulator to the riser pole or bus bar. Cable clamp portions must be constructed in many discreet sizes to accommodate various cable insulation diameters. A need therefore exists for an insulator with a clamp portion that can accommodate a variety of cable sizes.
In addition, most often the clamp portions of insulators are constructed using metal and/or porcelain components. While such materials function well, improvements in terms of weight, cost and durability are desirable.
An embodiment of the cable restraint insulator is indicated in general at 10 in
Body half 12 attaches to a riser pole or bus bar (in an underground vault or station) or other structure by use of a mounting hole indicated at 16. As used herein, the terms “pole” and “bar” mean the same structure. As illustrated in
As illustrated in
An enlarged view of thread-less bolt 15 is presented in
Thread-less bolt 13 of
While locking pins 46 and 50 are preferably metal spring pins (as illustrated in the figures), other types of fasteners known in the art may alternatively be used. Such fasteners may or may not require apertures in the thread-less bolts 13 and 15. For example, the locking pin could instead clamp down on the shafts of thread-less bolts 13 and 15. Such an arrangement may or may not require one or more grooves or slots formed in thread-less bolts 13 and 15. In addition, standard threaded bolts could be substituted for thread-less bolts 13 and 15 as the elongated retaining members and nuts used in place of locking pins 46 and 50 as fasteners. As yet another alternative, a plastic one-time use “zip” bolt could be used which functions the same as a zip tie but features a shaft portion instead of the prior art tie portion.
As illustrated in
The cable restraint insulator body halves 12 and 14, and the thread-less bolts 13 and 15 are preferably constructed of injection molded track resistant high density polyethylene (HDPE). To those skilled in the art of molding and casting, however, it is apparent that the materials may be of any number of materials such as HDPE, epoxies (Cycloaliphatics), or polyurethane and also that the cable restraint insulator body and bolts may also be cast rather than injection molded. As indicated at 62 in
As illustrated in
The embodiment of the invention described above therefore provides an improved cable restraint mount insulator and clamping system that incorporates a unique adjustable arrangement and method for securing the cable in the hanger mount and, in the preferred embodiment, a HDPE insulating material. Such materials are lighter in weight, electrically track resistant, lower in cost and generally non-breakable.
While the preferred embodiments of the invention have been shown and described, it will be apparent to those skilled in the art that changes and modifications may be made therein without departing from the spirit of the invention, the scope of which is defined by the appended claims.
This application claims priority from U.S. Provisional Patent Application Ser. No. 60/889,854, filed Feb. 14, 2007.
Number | Name | Date | Kind |
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1997109 | Fyfe | Apr 1935 | A |
4840581 | Leufert et al. | Jun 1989 | A |
Number | Date | Country | |
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20080190649 A1 | Aug 2008 | US |
Number | Date | Country | |
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60889854 | Feb 2007 | US |