Guards of this type are commonly used on guy wires of utility poles, which are located near walkways, yards, and streets where there is danger of injury to persons or damage to vehicles from impacts with a bare guy-wire. The guard assembly enhances the visibility of the guy-wire and in many cases prevents or reduces injury or damage from impact with it, as well as reducing such loss of utility service as is due to damage to the utility pole.
The earliest guy-wire guards in the electrical utility industry were made of wood, as the most available and least conductive material. (Dry wood is traditionally a safe material for touching a downed power line and avoiding electrocution). The California Public Utility Commission still states that all guy wire guards should be eight feet in length, made from a substantial material of either wood, metal, plastic, or other suitable material, thus showing the erstwhile primacy of wood as a guy wire guard.
The earliest wooden guards were as simple as a piece of approximately one-by-four-by-eight board. More sophisticated guards were approximately eight-by-one-by-three rectangular boxes; i.e., four boards nailed together. The most sophisticated wooden guards were bundles of eight-foot-long triangular-shaped slats lashed together by metal bands. All of these wooden guards were often painted black and white like the old railroad crossing barriers.
With the advent of the telephone industry and its utility poles, which do not carry power sufficient to electrocute, metal guards made their appearance on the scene. Sales and Standards personnel argued that metal would outlast wood, was more difficult to vandalize, and was appropriate for telephone guy-wire guards. Furthermore, it was argued that metal would also be better for the electrical utilities, for the same reason. It was said that the chances of anyone being electrocuted by downed power lines was miniscule, compared to the savings in cost of replacement of wooden guards. However, the awareness of the public of their legal rights and the perception of utilities as "deep pockets" has made use of metal risky for guy-wire guards.
With the advent of plastics, various plastic guards became popular among both the telephone and electrical utilities. It was argued that they would last longer than wood, were safer and less expensive than metal, and were lighter and easier to handle and store than either wood or metal. Plastic guards practically became a fad among both types of utilities, until it was discovered that they degraded and broke up under prolonged subjection to the ultraviolet content of sunlight, and that they were easily vandalized, i.e., were easily twisted, pushed up, or pulled down on the guy-wire.
Guy-wire guards made of plastic, especially polyethylene, not only broke down, i.e., were degraded by micro-cracks and disintegrated from ultraviolet penetration. They also burned easily, creating a new danger in outlying farm and wooded areas. Moreover, as time went on, these plastic guards were made less and less substantial in order to outweigh the labor-intensive cost of replacing them. The less substantial they became, the more easily vandalized or damaged from impacts they became, and, consequently, the less they protected the public and the pole.
The trend in the industry then became to move back to metal guards and take the chance of liability suits involving personal injury and wrongful death. Another trend in the industry was to move to only polyvinyl chloride guards, which would not burn, but they still broke-up under the exposure to ultraviolet light. No company wanted to buy high-ultraviolet resistant, exterior guards of polyvinyl chloride because of their initial expense and their high replacement costs when they were damaged by vehicle impacts and vandalism.
All of the above-described types of guards used fastening systems that allowed impacts from vehicles or vandals to bump them loose from the guy wires.
Furthermore, the fasteners used on most previous guards were made of galvanized metal. When a galvanized nut was threaded on a galvanized bolt, the threading would break the galvanized coating, and then rust would form under the broken coating and eventually cause the fasteners to disintegrate, so that the guard would eventually fall off the guy-wire.
Most of the previous guards used fasteners that fitted tightly on the guard and the wire. The tension on the guy wire would cause them to loosen under vibration. Also fasteners that were tightened down firmly would tend to crack plastic guards, especially in the presence of ultraviolet radiation, or, in the case of metal guards, the tight fit would (as said) break the galvanizing and lead to rusting.
Most guards previously designed did not cover the anchor rod down to the ground. In fact, many plastic guards were designed to cover the wire only above the anchor rod and hardware clamps (used to form a loop where the wire doubled back on itself), leaving the anchor rod, hardware, and wire tails exposed and creating the hazard of tripping pedestrians or injuring them with the exposed sharp edges.
Lastly, all previous guards, with the exception of the W. C. Vaughn guard (U.S. Pat. No. 4,223,491), were not designed to house the guy-wire completely, including the anchor rod, looping hardware and dangerously sharp wiretails.
The present invention is an attempt to solve these problems that have been associated with previous guards.
Previous attempts to solve the general problem are illustrated by U.S. Pat. Nos. 1,485,994; 1,630,356; 1,645,748; 1,765,823; Re. 19,639; 1,995,503; 2,880,828; 3,057,443; 3,173,519; 3,251,161; 3,425,456; 3,900,697; and 4,223,491.
In a typical present day situation, such as a utility pole, the guy-wire extends from a connection high up on the pole down to a ground anchor, which typically includes a rod having an eye through which the guy-wire is looped, the wire then being brought back on itself and held with clamps or other wire grippers. Preferably, a guard for such a guy-wire desirably covers the wire from a level somewhere near the ground anchor up to a level of about 8 feet or more above the ground.
An object of the present invention is to provide a guy-wire guard assembly, which is economical to manufacture, is simple to install, and when installed is difficult to bump loose, vibrate loose, or vandalize.
Visibility is an important feature of all such guards, and it is an object of the invention to provide improved visibility as well.
Most guards, heretofore, have either been open for about half their periphery or have been very small in diameter, so that, although they would cover the guy-wire itself, they could not cover the anchor at the ground or any enlarged portions. Also, such small-diameter guards were not very visible, nor were they substantial.
Vandalism has been a major problem with these guards; for, some people, including children, often seem to delight in damaging or destroying them. They sometimes twist them or pull them partly away from the guy-wire, push them up the guy wire, or otherwise mishandle them, so that the guards are no longer able to perform their function properly. This often happens with guards which are large enough in diameter to be used properly for visibility when new, but which protect only one side of the wire, so that the vandals can get at their interior as well as their exterior. Another problem with such guards is that damage from vehicles that pump into them easily dislodges them from the guy-wire.
Another problem with guard assemblies, heretofore, has been the difficulty of adequately securing them in a way which deters dislodging from impacts, vibration, and vandalism.
A further problem confronting these guard assemblies has been to protect them from the weather, especially where it may be relatively severe, for example, very hot in the summer and very cold in the winter. Ultraviolet rays, as said above, have tended to cause micro-cracking and eventual deterioration, so that the guards have often literally crumbled off the wire.
An additional problem has been to prevent damage from fire, for where polyethylene plastic guard members have been used, they have often been found to be quite inflammable.
Another problem with the prior-art types of plastic guards has been that they have been too flexible and therefore too easy for vandals to distort.
A major attraction to vandals has been that the fastening members, especially when made so that they can be removed for replacement or the like, have been too easily removed. Where the fasteners have not been readily removable, they have commonly corroded or rusted so that they were substantially useless after a while.
Metal guard assemblies have been often relatively rigid compared with those of plastic, but those of the prior art have been readily damaged; when they were bent by vehicle impact, they stayed bent and formed sharp edges that created an additional hazard. Even the best metal guard assemblies have presented hazards in storms, for they are conductors of power, when damage done by a storm sends power to them or when lightning struck them. Also metal guards have been quite expensive.
It is important that guard assemblies be recognized by the employees of the power companies and other such companies as being safe both from an electrical standpoint and from a physical standpoint, for some structures may cut or injure workers, as well as the public, and in other ways make the entire installation more dangerous than it was as a bare guy wire.