Fiber access terminal including moisture barrier plate

A fiber access terminal includes a drop cable side and a distribution cable side. The sides are separated by a frame to which a variety of cable management and cable connections components may be mounted. Optical fibers are routed from drop and distribution cables through a plurality of routing paths to splice trays for connection to other optical fibers. The terminal includes a base and a dome cover mounted to the base defining an enclosed interior. Passageways between the base and the dome cover are closed by removable covers to limit moisture and animals from accessing an interior of the dome cover. A tether connects the removable covers to the frame.

TECHNICAL FIELD

The present invention relates generally to provision of optical fiber telecommunications service. More specifically, the present invention relates to a fiber access terminal and a method of using a fiber access terminal.

BACKGROUND

As demand for telecommunications increases, optical fiber services are being extended in more and more areas. To more efficiently extend the fiber optic service into areas where current and future customers are located, often distribution cables with more then one optical fiber are utilized. To provide service to a particular premises in the area, the distribution cables may be received within a fiber access terminal. Such terminals provide a location in the field where one or more optical fibers of the distribution cable may be split out from the distribution cable. The remainder of the fibers within the distribution cable may then be expressed through the fiber access terminal to extend to another location where service is desired.

Within the fiber access terminal, a variety of fiber terminations and equipment is located. Typically, a base of the fiber access terminal is buried in the ground, and an upper portion of the fiber access terminal is positioned above the ground. There is a need to protect the fiber terminations and equipment within the fiber access terminal from contaminants, such as weather, water, debris, and animals.

SUMMARY

The present invention relates to a fiber access terminal including a base defining an interior and mountable to the ground. A dome cover defines an enclosed interior and is mounted to the base. A frame holds telecommunications equipment and is mounted to the base and extends into the interior defined by the dome cover. The frame and the base cooperate to define one or more passageways between an interior defined by the base and the interior defined by the dome cover. A removable cover is provided to close the one or more passageways. In such a manner, contamination of the interior of the dome cover and the telecommunications equipment contained within is lessened.

DETAILED DESCRIPTION

Reference will now be made in detail to the exemplary aspects of the present invention that are illustrated in the accompanying drawings. Whatever possible, the same reference numbers will be used through out the drawings to refer to the same or like parts. Referring now toFIGS. 1-11, a fiber access terminal10is shown including a base12, and a dome cover14which define a protected interior16. A frame18is mounted to base12and holds telecommunication equipment19, such as terminations, splices, and breakouts. The frame18is mounted to the base and extends into an interior20of dome cover14. A first end24of base12is mounted below ground level21. A second end26of base12projects above ground level and mounts to a bottom end28of dome cover14. Latches30,31mount dome cover14to base12.

Frame18includes a first side32and an opposite second side34. One or both of sides32,34can hold the telecommunications equipment. First and second sides32,34of frame18cooperate with second end26of base12to define first and second passageways42,44extending between an interior36of base12and interior20of dome cover14from base12. First and second passageways42,44can allow for undesirable elements to enter interior20of dome cover14, such as moisture and animals. Moisture in the air can pass from the ground into dome cover14and condense on dome cover14or on frame18and the telecommunications equipment. Animals, such as mice, can enter interior20of dome cover14from base12and disrupt the cable connections. Hand access to the passageways42,44is needed during system set up to allow the cables passing through the ground to pass through into dome cover interior20.

Terminal10includes a cover system50for selectively covering the first and second passageways42,44. In the preferred embodiment, cover system50includes a first removable cover52for closing first passageway42, and a separate, second removable cover54for closing second passageway44.

First removable cover52includes a top member62and a compressible base member64mounted to the top member62. The compressible base member preferably engages the frame18and the base12to close the first passageway42. The compressible base member64is preferably made from a material such as foam. Foam base member64and the other polymeric materials preferably meet the anti-fungus growth tests as specified in the GR-13-Core requirements for Telcordia Requirements for Outside Plant Enclosures, specifically the ASTM G-21 test. One example foam that is usable is SCE-41 neoprene, closed cell foam.

Preferably top member62of first removable cover52is planar in shape and is made from plastic, such as ABS. Foam base member64can be joined to planar top member62with adhesive. Preferably, top member62has a first outer edge portion66which extends beyond the outer edge portion of foam base member64such that a rim is defined to engage the top edge of base12when first removable cover52is in position to close first passageway42. In addition, an inner edge region72of first removable cover52includes the foam base member64extending beyond an edge of planar top member62in areas73in order to better close air passageways around cables entering interior20of dome cover14.

Second removable cover54is constructed in a similar manner and like parts are designated with an apostrophe (′). In cover52, areas73are used to seal around the distribution cables which bring service to and from terminal10. In cover54, area73′is used to seal around the drop cables which lead to customers' premises. Variations are possible in the perimeter shapes of first and second removable covers52,54in order to fit the first and second passageways42,44of differently shaped terminals. WhileFIGS. 7-11show covers52,54together, covers52,54are separate units. Covers52,54can be operated separately to selectively close or open passageways42,44.

A latch82is provided to hold first removable cover52in position so that first removable cover52does not inadvertently dislodge from its closed position. Latch82includes a pivoting member84which selectively blocks removal of first removable cover52from its position closing first passageway42. Similar latches82are provided to hold second removable cover54in position. Latches82are movable to allow later access to passageways42,44.

Frame18includes distribution cable clamps102,104on first side32of frame18. Distribution cable clamps102,104clamp to distribution cables extending to and from terminal10. In use, one or more of the fiber optic cables within a distribution cable is broken out into drop cables within terminal10. A remainder of the cables in distribution cable are expressed through terminal10.

Frame18includes a splice holder110. Frame18can also include fiber optic adapters114(seeFIGS. 13 and 23) for holding two fiber optic connectors115in axial alignment. One fiber optic connector connected at one of adapters114is spliced to one of the broken out fibers from the distribution cable entering terminal10. A second fiber optic connector connected to the first fiber optic connector at the selected adapter114is a drop cable, extending to a customer's premises. A drop cable clamp118on frame18holds the drop cable in a secure manner.

FIGS. 12-14show an alternative frame18′. Both of frames18,18′ include various structures to manage the cables, splices and terminations in an organized manner. For example, radius limiters170,172, tie-offs174, and clips176can be used.

To further hold the distribution cables to frame18, a strength member clamp122is provided to clamp to the strength member of a distribution cable. See alsoFIGS. 15-17. Clamp122includes a fastener mount124for mounting to frame18. Clamp122further includes a fastener clamp126for connecting to the strength member109. Screw127cooperates with housing125and tab129to securely hold the strength member109. Electrical grounds128for grounding the distribution cables can be used if desired.

Referring now toFIGS. 18-24, an alternative terminal10′ is shown with a base12, dome cover14, and removable covers52,54. To keep removable covers52,54from becoming separated from terminal10′, a tether140is used. Tether140includes a first portion142which connects first removable cover52to frame18′. A second portion144connects second removable cover54to frame18′. In one preferred embodiment, tether140is a single strap or other elongated member extending through a hole150in frame18′ with removable covers52,54connected at each end.

In one possible embodiment, tether140is made from an o-ring compressible material which is cut to define two ends. Each end152,154is passed through a hole162,164in each of removable covers52,54, respectively. Each end152,154is crimped with crimps182,184to prevent removable covers52,54from separating from tether140.

During use, tether140keeps removable covers52,54adjacent to frame18′. Should access to an interior of base12be desired, dome cover14is removed, exposing frame18′ and removable covers52,54. One or both of removable covers52,54is removed from their positions closing the passageways into base12. Tether140allows one or both of removable covers52,54to hang along side an exterior of base12. Tether140would prevent the user from reinstalling dome cover14onto base12, unless the removable covers52,54were back in the correct closed positions.

Frame18′ includes protrusions135to help prevent cover54from tipping, and possibly allowing access between base12, and dome cover14after cover54is placed in the closed position. Protrusions135are located below cover54in use. Cover52is prevented from tipping by latch30positioned above cover52during use.

In the field, distribution cable106enters terminal10,10′ from the ground (seeFIG. 1). One or more of the inner cables132of distribution cable106is broken out into one or more drop cables116(seeFIGS. 1,23and24), which lead to the customers' premises. A remainder of the cables132are expressed through terminal10,10′ at cables133and exit terminal10,10′ at distribution cable108back into the ground (seeFIGS. 1 and 24). Cable108passes to another remote terminal10,10′, or other location where service is desired. Within terminal10,10′, the cable or cables132to be broken out are connected through splices at splice holder110, and possibly a fiber optic adapters114to the drop cables116. Cables117link the splices at splice holder110to the fiber optic adapters114connected to the drop cables116(seeFIGS. 23 and 24). Strength members109associated with distribution cables106,108are clamped with strength clamping members122to frame18,18′. Ground wires111can be linked to frames18,18′ with electrical grounds128.