Patent Application
20090279287
Embodiments are generally related to airport runway light systems and installations. Embodiments are also related to elevated lights for use in airport runway light systems. Embodiments are additionally related to safety power cut-off switches utilized in the context of elevated lights.
Modern airports incorporate numerous specialized elevated lighting systems for illuminating the edge of an airport runway, taxiway and parking areas and to minimize the possibility that an aircraft may inadvertently travel off the edge of the runway. A typical elevated lighting system includes the use of (but is not limited to) approach lights, threshold and runway end, runway edge, and taxiway edge lighting systems. In particular, the United States FAA (Federal Aviation Administration) and a variety of aviation regulating agencies across the globe have mandated the use of elevated lights along runway edges and strongly recommend taxiway edge lights for certain low visibility operations. The elevated lights can be specially designed to define the edge limits of runways and taxiways and inhibit pilots from inadvertently driving airplanes off the designated runways and taxiways.
Elevated lights can include the use of a light fixture assembly that is attached to a base cup embedded in the ground. A typical light fixture assembly includes a mast with an end, which is attached to a coupling of a base cup, and an opposing end that carries a light fixture. The mast projects upwardly from the coupling of the base cup and support the light fixture above the ground in order to provide elevated lighting. An electrical plug is typically provided at the bottom of the mast to couple the electrical wiring of the light fixture to the electrical wiring of the airport.
Such elevated lights may also include a frangible joint at the base of the mast in the coupling region of the base cup. The frangible joint is referred as a frangible coupling. The frangible joint permits the coupling of the base cup to break when struck by a plane or other vehicle, which is a common occurrence at the airports. The electrical plug can be adapted to decouple when the coupling breaks to prevent damage to the electrical wiring of the airport. Such a frangible joint can separate the light fixture assembly from the coupling attached thereto to fall away from the base to minimize damage to the aircraft.
In the majority of prior art elevated lights, the light fixture assembly with the mast can be broken away from the base when the elevated light is struck by the airplane. Hence, the electrical connection can be disconnected by means of an electrical plug when the mast is separated from the base cup. The disconnection of the electrical plug typically leaves an open circuit of, for example, 6.6 amps and upwards of 480 volts alternating current (VAC), which can lead to a potential hazard for maintenance workers and environments. Therefore, it is desirable to provide some technique or apparatus for disconnecting the power from the power coupler to achieve a safe and operational airfield lighting system without the need to disconnect the wire in the mast.
In an effort to address the foregoing difficulties, it is believed that a need exists for an improved elevated light that enables a quick disconnection of the electrical connection in the event of mast breakage. It is believed that the improved elevated light disclosed herein can address these and other continuing needs.
The following summary is provided to facilitate an understanding of some of the innovative features unique to the embodiments disclosed and is not intended to be a full description. A full appreciation of the various aspects of the embodiments can be gained by taking the entire specification, claims, drawings, and abstract as a whole.
It is, therefore, one aspect of the present invention to provide for an improved elevated light for airport runway light systems.
It is another aspect of the present invention to provide for a safety power cut-off switch utilized in the context of elevated lights.
The aforementioned aspects and other objectives and advantages can now be achieved as described herein. An improved elevated light for an airport runway light system comprises a mast mounted to a base plate, which is attached to a base-cup. The mast can be designed as hollow to allow internal electrical connection between a light source in a light assembly and an isolation transformer in the base-cup. The mast can include a frangible break joint that cleanly separates the mast from the base plate. A safety power cut-off switch can be fixed into the base plate on the base-cup. The power cut-off switch can be positioned in the frangible break joint so that a switch button can be held closed by a breakaway portion of the frangible break joint. In the event of mast breakage, the switch button can be released to open electrical circuits for quick disconnection of the electrical connection.
Furthermore, the light assembly, the mast and the base-cup can be arranged in a substantially vertical alignment. The mast can be attached with the light source of the light assembly utilizing a set of screws. The frangible joint can also be referred to as a “frangible coupling” and an insert associated with the frangible coupling can be provided near to the power cut-off switch. The power cut-off switch can be designed as a micro switch, which is normally closed when the switch button is depressed. The power cut-off switch can be opened for turning off power to connectors attached to the base plate when the mast is damaged. Hence, it enables easy and safe repair of the elevated light after the mast breakage without the need to disconnect power to a light fixture.
The accompanying figures, in which like reference numerals refer to identical or functionally-similar elements throughout the separate views and which are incorporated in and form a part of the specification, further illustrate the embodiments and, together with the detailed description, serve to explain the embodiments disclosed herein.
The particular values and configurations discussed in these non-limiting examples can be varied and are cited merely to illustrate at least one embodiment and are not intended to limit the scope thereof.
Moreover, the mast 110 and the base plate 112 can be combined to act as a light fixture 140. The light fixture 140 can be mounted on the ground 104 with the help of mounting means 134. The base-cup 114 can provide a source of power through a power coupler 116 by utilizing a set of electrical leads 118. The power coupler 116 can further be connected with a main power line (not shown) in the airport runway light system 300. The power coupler 116 can act as an isolation transformer for coupling power from the main power line, which extends to one or more elevated lights 100 through the ground 104. Such an isolation transformer 116 in the base-cup 114 can provide the required power to the light source 106 via the mast 110.
The mast 110 secures to the base-cup 114 to provide a stable support for the light assembly 102 during harsh weather conditions or other conditions impacting operation and/or orientation of the elevated light 100. The light assembly 102, the mast 110 and the base-cup 114 can be arranged in a substantially vertical alignment. An adjustment means 120 can be provided at the junction of the base of the light assembly 102 and the mast 110 so that the light source 106 can be adjusted to maintain a vertical orientation. The mast 110 can be designed as hollow to allow internal electrical wires 122 between the light source 106 in the light assembly 102 and a set of connectors 124 in the base-cup 114.
The mast 110 further includes a frangible break joint 126 that enables an easy breakaway of the mast 110 from the base plate 112 when an airplane 350, as illustrated in
In addition, the frangible break joint 126 includes a groove or insert that is scored into the mast 110. The mast 110 is a single piece of hollow pipe extending from the light assembly 102 to the base plate 112. The groove or the insert of the frangible joint 126 can be designed with a sufficient length, depth, and orientation in the mast 110 to facilitate separation of the lighting assembly 102 and the light fixture 140 from the base plate 112 at or near the surface of the ground 104. In any case, the function of the frangible coupling 126 is to facilitate a breakaway function under stressed conditions to protect the elevated light 100 and the airplane 350 from major damage.
Such a frangible coupling 126 can provide a permanent and/or temporary mounting system for the elevated lights 100. The frangible coupling 126 can be manufactured based on FAA (Federal Aviation Administration) compliance for high and medium intensity edge light requirements. Additionally, the base-cup 114 can be acted as a blank cover to house the power coupler 116. The power coupler 116 can be operatively and electrically connected to the light source 106 of the light assembly 102 via the power cut-off switch 130 for providing power thereto. The power cut-off switch 130 can be designed as a micro switch, which is normally closed when the switch button 131 is depressed. The power cut-off switch 130 can be opened for turning off power to the connectors 124 attached to the base plate 112 when the mast 110 is damaged. Hence, it enables easy and safe repair of the elevated light 100 after the mast breakage without the need to disconnect power to the light fixture 140.
It will be appreciated that variations of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also, that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.
