The present invention relates generally to electrical, electronic or communication cables and, in particular, to synthetic tensile members for supporting such cables in generally vertical passageways.
From time to time, it is necessary to install cables in a vertical application where the length of the cable being installed, the cable construction or the physical circumstances of the installation require that the cable include dedicated construction members for either temporarily or permanently supporting the cable length. Historically the cable weight has been supported by a number of different techniques including:
a) steel wire armor helically applied to the cable and used to support the weight;
b) messenger wire lashed to the cable for supporting the weight; and/or
c) the use of High Tensile strength members integrated into the design of the cable core and the core covered with a layer of interlocking steel or aluminum armor. The cable is constructed so that the armor “locks” the components in place by restricting radial movement and an untwisting of the core.
With reference to
As greater and greater depths are addressed and cables get longer and longer, the weight of the steel tensile members precludes their use. The steel weight makes the cables heavier and so larger tensile members are needed adding to its weight until there is no room left for any payload.
In the embodiments of the cable of the invention illustrated in
The jackets 36 and 46 may be extruded and, as examples only, constructed from materials that include polyvinylchloride (PVC) or nylon.
In both of the embodiments of
The synthetic strands or cords 30 or 40 preferably are made of synthetic fibers such as those sold under the trade names TECHNORA (which is a para-aramid fiber made from co-polymers) or DYNEEMA, but alternative synthetic fibers offering high strength combined with light weight may be used. Synthetic fibers additionally having high heat capacity are desirable as well.
The cable 50 of
The tensile members 52 are also preferably constructed from synthetic fibers such as those sold under the trade names TECHNORA or DYNEEMA, but alternative synthetic fibers offering high strength combined with light weight may be used. Synthetic fibers additionally having high heat capacity are desirable as well.
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.
This application is a divisional application of U.S. application Ser. No. 14/813,918, filed Jul. 30, 2015, entitled Cable Having Synthetic Tensile Members, which claims priority to U.S. Provisional Patent Application No. 62/030,660, filed Jul. 30, 2014, entitled Cable Having Synthetic Tensile Members, the entire contents of which are hereby incorporated by reference.
Number | Date | Country | |
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62030660 | Jul 2014 | US |
Number | Date | Country | |
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Parent | 14813918 | Jul 2015 | US |
Child | 15983993 | US |