Mast-type outdoor lighting system

Abstract

An improved outdoor lighting system is provided that comprises a light assembly formed from at least one tubular mast having a distal end for supporting an electrically powered light source, and a proximal end mounted in the ground, and an electrical cable for connecting the light source to an underground power source. The improved system includes an electrical connector assembly in the cable located in the vicinity of the ground-mounted distal end of the tubular mast. The electrical connector assembly spontaneously disconnects in response to an application of an tensile force indicative of an automobile collision with the mast, thereby preventing damaging tensile forces from being transmitted along the underground portion of the cable to the circuit breaker. The system further comprises an underground fuse assembly and lightning arrestor, both of which are mounted in an underground box electrically connected between the circuit breaker, and the underground portion of the cable that terminates in the aforementioned connector assembly. The remote, underground location of the fuse assembly and lightning arrestor provides easy and safe access to these components by maintenance personnel while discouraging vandals from tampering with or stealing these components.

Description

[0001]This reissue application of U.S. Pat. No. 5,335,160 is a continuation of reissue application No. 10 / 364,510 filed Feb. 12, 2003, which in turn was merged with reexamination application Nos. 90 / 005,715; 90 / 005,719 and 90 / 006,130 previously filed on Apr. 28, 2000, May 4, 2000 and Oct. 16, 2001, respectively.BACKGROUND OF THE INVENTION[0002]This invention generally relates to outdoor lighting systems for illuminating highways or airports and the like, and is specifically concerned with an improved system of the type wherein outdoor lights are mounted on a plurality of spaced-apart tubular masts and powered by a common, underground circuit breaker.[0003]Outdoor lighting systems for illuminating streets and highways are known in the prior art. Such lighting systems typically include a plurality of lighting units spaced along the road or highway, each of which includes an electric light that is supported on the distal end of a tubular mast whose proximal end is anchored into the gro...

AI Technical Summary

Benefits of technology

"The invention is an improved outdoor lighting system that is safer in the event of a collision with a vehicle. The system includes an electrical connector assembly that disconnects upon the application of a tensile force, such as a collision, to prevent damage to the connection. The system also includes an underground fuse assembly and lightning arrestor to protect the system from damage caused by lightning striking the light source. The fuse assembly and lightning arrestor are mounted within the mast to discourage vandals from damaging them. The improved system results in safer and more reliable outdoor lighting."

Problems solved by technology

Additionally, the wrenching tensile forces applied throughout the length of the cable just before the breakage thereof at the fuse assembly splices often weakens splices and other connections made with adjacent lighting units, setting the stage for further maintenance problems that are difficult to diagnose and solve.

While such prior art lighting system are widely used to illuminate streets, highways, and virtually any place where large amounts of outdoor lighting is required, the applicant has observed a number of shortcomings associated with the design of these systems which significantly impairs their overall usefulness.

For example, if one of the masts of such a system should be knocked down as a result of an automobile collision, the stresses applied to the cable within the mast often causes it to break at the connections made with the fuse assembly.

As these connections are typically made by way of splices, the tension applied to the cable from the automobile collision tears the splices apart, dangerously exposing wires that are “hot”.

These exposed, hot wires can in turn conduct dangerous electrical currents through the knocked-down mast (which is typically made of a conductive metal) or even the body of the colliding car.

Even if the collision causes the exposed conductors of the broken cable splice to short circuit and trip the circuit breaker, this somewhat safer result is not partially desirable, as such tripping will cut off the current flowing to all of the other mast-supported lights that are serially connected to the breaker, thus surrounding the area around the broken mast in total darkness if the collision occurs at night.

Additionally, the wrenching tensile forces applied throughout the length of the cable just before the breakage thereof at the fuse assembly splices often weakens splices and other connections made with adjacent lighting units, setting the stage for future maintenance problems that are difficult to diagnose and solve.

Because such masts usually have openings at their upper ends or sides for structural reasons, the interior of such masts often becomes the home of wildlife that is either potentially hostile (such as wasps, poisonous snakes, or rats) or of the type apt to build nests around these components (such as birds or squirrels).

The presence of such animal life significantly impairs the replacement of fuses of burned-out lightning arrestors by either assaulting the maintenance personnel who carry out such operations, or by creating physical obstructions (such as nests) that must be removed incident to such operations.

Additionally, the spliced connection between the lightning arrestor and the cable that supplies electrical power to the light source makes it difficult to replace this component in the event of a burn out of the surge arrestor circuit in the arrestor from a bolt of lightning striking the conductive mast.

The present access panels are easily opened by vandals who may tamper with or destroy the components inside, or by thieves who attach the cable leading to the circuit breaker to a truck and pull it out of the ground for the purpose of selling the relatively large amounts of copper in it.

In recent years, such vandalism and theft has been a major drain on the maintenance budgets for such lighting system in both the public and the private sectors of the economy.

Such a system should further make is difficult, if not impossible, for vandals or thieves to destroy or steal large lengths of heavy copper cables or other valuable components located inside the masts.

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