This United States Non-Provisional Patent Application does not claim priority to any United States Provisional Patent Application or any foreign patent application.
The disclosures made herein relate generally to cabinets for telecommunication equipment. The invention discussed herein is in the general classification of underground cabinets for telecommunication equipment.
VDSL (Very-High-Bit-Rate Digital Subscriber Line) cabinets are enclosures for holding various electronics, including telecommunications equipment and the like, which generate heat when in use.
There is a very significant public and civic resistance to placing above-ground cabinets deep within a network (as required by Lightspeed VDSL service). Hence, most cabinets must be placed below ground where it is more difficult to efficiently dissipate heat from the use of the electronics within the cabinet.
VDSL cabinets also need to be placed much deeper in the neighborhood than DLC (Digital Loop Carrier) service, closer to homes and businesses, leading to a slower deployment rate. This requirement raises service provider costs for easements and right of ways. It also often results in litigation with civic authorities and may lead to denial of permits for deployment of infrastructure in city right-of-ways.
U.S. Pat. No. 6,316,728 entitled “Cross-Connect Cabinet” discloses a cross-connect cabinet for an underground telecommunication installation wherein the bundle of conductors electrically connecting the splice connector with a pivoted terminal field is so constructed and arranged to avoid bending the bundle of conductors across the longitudinal axis of the conductors in a manner likely to cause fatigue or other premature conductor failure during the opening and closing of the terminal field of the cross-connect cabinet.
This cabinet is inadequate because it is intended for use with passive electronic components and does not provide a cooling mechanism for active electronics. It also primarily focuses on twisting the cables rather than bending them as the cross connect field comes up for service.
United States Patent Application No. 2007/062670 entitled “Casing with Cooling Means” discloses a casing for containing apparatus which in use generates heat, the casing including a heat-exchanger arranged to act as a removable wall, preferably a lid, of the casing, and fluid directing means arranged to be on the exterior of the removable wall for directing a heat transfer fluid in thermal contact with the wall in use, such that heat generated in the interior of the casing is transferred to the heat transfer fluid by conduction through the material of the wall.
This casing is inadequate because it utilizes a sealed air-to-air heat-exchanger with the heat-exchanger as part of the removable cover. The heat is either dumped into the surrounding vault fluid or through heat pipes buried in the ground remotely. This solution tends to be costly, bulky and not effective for high power densities.
U.S. Patent Application No. 20006/000,628 entitled “Underground Cabinet Cooling Apparatus and Method” discloses a connection system for interconnecting communication media with a housing including a cavity and an airflow opening, a cover adapted to cooperate with the housing to define an air reservoir, and an airflow agitator for causing air to move from the air reservoir to the housing through the airflow opening. The air reservoir contains at least a portion of the housing including the airflow opening. The air reservoir and the housing cooperate to prevent fluid from entering the cavity. One method for dissipating heat within a connection system comprises providing a connection system including a housing with an airflow opening and a cover adapted to cooperate with the housing to define an air reservoir containing at least a portion of the housing and the airflow opening. The method further includes forcing air from the air reservoir to the housing through the airflow opening.
This solution is inadequate because it is essentially an actively vented Bell Jar approach that does not address moisture control within the electronics cavity. Internal heat is dumped into the surrounding vault fluid. This does not address functionality under flooding conditions or provide for internal moisture/condensation control. The inlet/exhaust are integral to the enclosure and draw cooling air within the immediate surrounding air which also is ineffective.
Publication No. WO 2004/091,065 entitled “Connection System” discloses a junction box to seal the contents from the effects of dust and moisture while providing convenient access inside the box. The junction box has a housing defining an internal cavity, an opening to allow access, one or more apertures extending through the housing to receive communications media, one or more connectors mounted within the housing adapted to interconnect the communications media extending through the aperture(s) and a cover adapted to cooperate with the housing to define an air reservoir containing at least a portion of the housing including the opening, the reservoir and the housing cooperating to prevent fluid entering the cavity.
This system is not adequate because it is defined as an airtight enclosure (which may be underground) for cable connections, and has no mechanism for cooling active heat dissipating electronics or controls, either through sealed heat-exchanger or through venting while maintaining dry air inside. The invention disclosed also uses a pivoting frame to access the “connectors” but not the electronics.
U.S. Patent Application No. 2002/196605 entitled “Purge and Cooling System for Enclosure for Hazardous Environment” notes that a purge system develops a positive pressure in an enclosure, with sufficient volumetric air flow to cool the electrical components. The system includes an air inlet hose, with the input into the inlet hose positioned in an unclassified (i.e. safe) area. The inlet hose couples to the suction of an air blower, which may be mounted inside or outside the enclosure, while the discharge of the air blower is inside the enclosure, thereby providing the necessary positive pressure (purge) within the enclosure. The air discharged from the air blower strikes a baffle, which distributes the blowing air throughout the bottom of the enclosure. The distributed air is then drawn into controller cabinets by dedicated cooling fans. A conduit system connects the controller cabinets to take the now heated air from the cabinets to a discharge outside the enclosure. The outlet of the conduit system may include a counter-weighted flapper valve to maintain the pressure within the enclosure.
This system also is not adequate because it is devised to deliver constant cooling air, above local atmospheric pressure, in an above-ground equipment enclosure to prevent ingress of explosive external gases.
In addition, U.S. Pat. Nos. 6,164,369, 6,877,551 and 6,889,752 involve heat-exchanger and “waterproof” cabinets but they are actually only “water resistant” and lack the other features required in an underground application as discussed herein.
Hence, there is a need in the art for a convenient to install, reliable, inexpensive, durable, safe and effective device for holding active electronics equipment that can be located underground and that has appropriate venting to control cooling and moisture and provide for safe remote venting outside of the electronics enclosure of battery compartment gases.
Flush to Grade Underground Cabinet is an underground, heat dissipating, electronics cabinet/enclosure that employs remotely vented above-ground atmospheric air to meet electronics cooling and moisture control requirements, including existing and anticipated future battery technology.
The preferred embodiment of the invention utilizes a vault having air ducts passing through it leading to an above-ground ventilation pedestal on one end and an enclosure inside the vault that houses batteries and electronic equipment on the other end. The preferred embodiment also is a hybrid system utilizing a closed loop heat-exchanger that cools electronics while managing moisture and eliminating dust/pollution with filters while using tubes to vent battery compartment gases.
Alternative embodiments of the invention may incorporate different heat-exchangers, different ventilation pedestals or points, different heat-exchanger locations, different techniques for moisture control air ducts, sumps for moisture control, dehumidifiers, and a variety of latching devices for the vault and enclosure and lifting devices for the various components.
The principal object of this invention is to provide a device that houses electronics equipment, including telecommunications equipment, in a protected environment and can be located underground.
Another object of this invention is to provide a device for housing electronics that has appropriate cooling means for electronics equipment, including active heat-dissipating electronics components.
Another object of this invention is to provide a device that has appropriate venting to control moisture.
Another object of this invention is to provide a device that reduces public/civic resistance to installation because it is underground and out of sight.
Another object of this invention is to provide a device that does not create public safety concerns.
Another object of this invention is to provide a device for housing electronics that is relatively inexpensive to install and maintain.
Another object of this invention is to provide a device for housing electronics that is relatively inexpensive to manufacture.
Another object of this invention is to provide a relatively small device for housing electronics.
Another object of this invention is to provide an easily installed device for housing electronics that preferably requires only one day of site preparation.
Another object of this invention is to provide a reliable device for housing electronics.
Another object of this invention is to provide a device for explosive battery gas venting.
Yet another object of this invention is to provide a durable and water resistant device for housing electronics.
The preferred embodiment of Flush to Grade Underground Cabinet is comprised of at least some of the following: a vault having air ducts passing through it leading to an above-ground ventilation pedestal on one end and an enclosure inside the vault that houses batteries and electronic equipment on the other end. The preferred embodiment also is a hybrid system utilizing a closed loop heat-exchanger that cools electronics while managing moisture and eliminating dust/pollution with filters while using tubes to vent battery compartment gases.
The enclosure 24 also has standard Out Side Plant (OSP) cable terminations 27 with heatshrink techniques/materials commonly used for repeaters and optics located on the front.
The enclosure 24 is shown shifted to one side of the vault 20 to allow maximum room within the vault 20 for sealing and terminating the first air duct and second air duct, terminating grounds and bolting down the enclosure 24 to the vault 20 or to a concrete anchor pad beneath the enclosure 24. The enclosure 24 is approximately rectangular and is 60 inches in length, 42 inches in width and 30.3 inches in height. The dimensions of the enclosure also vary with the length usually ranging from 60 to 88 inches, but it is adaptable to any reasonable size and relatively high rate of heat-dissipating electronics equipment.
Crane lifting eyelets 42 (features) are also located on the upper corners of the enclosure 24. Bolt down eyelets 43 (features) are also located on each lower corner of the enclosure 24 to allow the enclosure 24 to be bolted to a concrete anchor pad to combat buoyancy forces during a flood. The first pressure coupling 25 and second pressure coupling 26 are also visible in this view.
In some embodiments, a Power Transfer Switch (PTS) and AC Utility meter base are integrated with the ventilation pedestal to reduce footprint, cost and number of installations. The PTS function is sometimes used to provide enclosure gas generator AC power during commercial AC power outages.
A ventilation pedestal could be as simple as two pipes sticking out of the ground with a cover to prevent rain ingress. However, in most embodiments, the ventilation pedestal will have cosmetic treatments, acoustic abatement features, and the ability to be co-located next to existing telecom structures and right-of-ways or easements.
Condensation management can be further enhanced by using insulated ducting or ducting arrangements that are self-insulating. For example, the intake pipe can be located inside the outlet pipe with insulation between the pipes and from the soil.
Most embodiments of the invention are intended to provide a one-hundred percent flush-to-grade underground active electronics cabinet with a volume of at least 42 cubic feet and the capability of housing 384 lines of xDSL equipment and supporting electronics, protection, power connection and control systems. Most embodiments also maintain an enclosed electronic high thermal density/dissipation system of at least 2 kW at 46 degrees Celsius external ambient and can protect against water intrusion, ideally at least 7 days at 10 feet of water head.
Most embodiments utilize the simple and cost-effective screw jacks lift systems for the electronic system and battery to make access thereto easy and help affect faster maintenance and repairs and provide more safety than cable winch systems.
To use the preferred embodiment of Flush to Grade Underground Cabinet, an individual would install the vault, concrete pad and enclosure underground, preferably six inches to one foot below grade. The ventilation pedestal would be placed above-ground and connected to the enclosure through the vault via the first air duct and the second air duct attached to the first pressure coupling and the second pressure coupling. The enclosure is preferably bolted down to an optional concrete pad to secure it from forces during flooding conditions. When servicing is required, the lid of the vault is unbolted and the cover dog latches of the enclosure cover are undone. The cover of the enclosure is then lifted and the pivoting arms are locked in place. The equipment rack can be moved out of place via the equipment lifting mechanism if access to the battery tray is desired. The battery tray screw jack can be used to raise the scissor lift under the battery tray for easier servicing.
The preferred embodiment of the device having a heat-exchanger permits fans to pull cool air coming from the ventilation pedestal through the first air duct and into the enclosure through the heat-exchanger and into a battery tube connected to the battery tray. A separate battery tube also permits warm air and gases from the battery tray to travel into the heat-exchanger and out of the enclosure through a second air duct connected to the ventilation pedestal. Certain embodiments having a sump prevent water from being pulled into the enclosure.
The materials utilized for Flush to Grade Underground Cabinet may vary widely but will likely include metal, plastic composite and electronic components. The metals used for the enclosure would ideally be selected from available steel or alloys of steel and aluminum. The production process related to the use of these metals insures that the material is non-corrosive, durable and strong. The selected metal should have high impact strength and be capable of accepting and retaining coloring materials for an extended length of time.
The materials used in the production of the device will ideally be selected for durability and longevity. Thermoplastics are commonly used in the manufacturing of components similar to those used in this invention. Polyethylene, polypropylene, and other similar thermoplastic materials would be among those with the necessary traits. Members of this family are recognized universally as being versatile and of high quality.
The plastic/composite components of Flush to Grade Underground Cabinet can also be formed with the use of plastic molding techniques, such as injection molding or blow molding. Injection molding requires melted plastic to be forcefully injected into relatively cool molds. As the plastic begins to harden, it takes on the shape of the mold cavity. This technique is ideal for the mass production of products. Alternatively, blow molding, a form of extrusion, could be utilized. Blow molding involves a molten tube being pushed into a mold. Compressed air then forces the molten tube against the cold walls of the mold.
It should be obvious that the components of the present invention can be of various shapes and sizes. It should also be obvious that the components of the invention can be made of different types of plastics, metals or other suitable materials and can be of any color.
Although this invention is discussed in conjunction with VDSL cabinets, it is applicable to many other services and technologies, including telecom and IP. It is also suitable for use as an active electronics cabinet close to the home such as with fiber to the home.
It will be recognized by those skilled in the art that changes or modifications may be made to the above-described embodiments without departing from the broad inventive concepts of the invention. It should therefore be understood that this invention is not limited to the particular embodiments described herein, but is intended to include all changes and modifications that are within the scope and spirit of the invention as set forth in the claims.