Joints and connections – Distinct end coupler – Interrupted periphery – e.g. – split or segmental – etc.
Reexamination Certificate
1999-09-30
2001-09-04
Kim, Harry C. (Department: 3629)
Joints and connections
Distinct end coupler
Interrupted periphery, e.g., split or segmental, etc.
C403S338000, C174S092000
Reexamination Certificate
active
06283670
ABSTRACT:
FIELD OF THE INVENTION
The present invention generally relates generally to splice case closures of the type which have two halves that are to be sealed together, and in particular to a clamping mechanism for sealing the halves of such a closure together.
BACKGROUND OF THE INVENTION
Two or more cables, such as telecommunications cables, must often be spliced together to extend or tap into a cable. The formation of a splice involves removal of the outer jacket and other layers of the cable to expose the individual conductors or optical fibers which are then individually connected to the conductors or fibers of another cable or cables. After the splice is formed, it must be protected from water and other vapors to prevent corrosion or a short circuit. For this purpose, the splice area is often enclosed in a splice case that is formed from two trough-like shell members having end plates through which the cables pass. The effectiveness of the splice case depends significantly on the mechanism used to seal the seam formed at the interface where the two shells meet.
In one known sealing arrangement, the two shell members each include integrally formed flanges that contact one another to form a seam. The seam is sealed by a series of bolts that pass through the flanges. Closure systems of this type are shown, for example, in a 1990 product catalog published by PSI Telecommunications Incorporated, entitled “2-Type Closure System”. One problem with this arrangement is that the force exerted by the bolts is not uniform across the seam. Rather, the force is at a maximum in the vicinity of the bolts and is reduced at locations between the bolts. As a result, the bolts must be closely spaced along the seam to ensure an adequate seal, thus increasing the cost of the splice case and the installation time associated with its use
In other sealing arrangements, the flanges receive clamping elements that extend along the seam. The clamping elements apply pressure to the flanges across their entire length. As disclosed in U.S. Pat. Nos. 5,048,916 (Caron) and 4,715,740 (Pichler), for example, the flanges and clamps are wedge-shaped so that the clamps can be more easily slipped over the flanges. While this arrangement can provide a relatively uniform pressure distribution across the seam, the pressure distribution is very susceptible to any irregularities in the wedges arising from the moulding process. Moreover, clamping mechanisms of this type requires the clamp to travel a significant distance over the flange. During this assembly process, the sealing force often becomes so great that it cannot be completed without the use of a tool. Indeed, clamps of this type are often hammered into place when they are installed in the field. This process can damage copper wire splices and the seal integrity for the closure, and is unacceptable for fiber optics splices. Moreover, because of the significant travel distance that is required to engage the flange, the size of the work area in which the closure is assembled and disassembled will also need to be correspondingly large. This is frequently problematic in the field, since the splice case is often installed in confined spaces such as a manholes or hand holes where there is very little space beyond that occupied by the splice case itself. Accordingly, there is a need in the art for a sealing arrangement for a closure, such as a splice case, in which uniform pressure is applied across the seam, which is easily engaged and disengaged from the closure (e.g., by hand), and which requires a minimum amount of working space for the clamp to be permanently mounted to the closure.
Another problem with prior art closure systems is that the closure mechanism is not permanently attached to the closure housing. Indeed, the length of many prior art closure ramps makes permanent attachment of the closure to the housing impractical. As a result, when access to the closure is desired, the clamps, bolts, or other closure devices must be removed from the splice enclosure until the work is completed. Since splice closures are frequently installed on elevated utility lines, the removed parts are easily dropped or lost, thus adding to the time and cost of work on the splice closure and often resulting in the closure system being reassembled improperly and without all of the original parts. There is thus a need in the art for a closure system in which the sealing or clamping mechanism can be permanently attached to the closure housing.
These and other needs are met by the present invention, as hereinafter described.
SUMMARY OF THE INVENTION
In one aspect, the present invention relates to a closure, such as a splice case, and a clamping element used to seal the closure. The closure comprises two sections that are joined together along adjoining flanges. The flanges are equipped with a plurality of spaced engagement elements (e.g., as opposed to a single wedged-shape flange), and the clamping element is adapted to interlock with the engagement elements in such a way that the clamping element only needs to travel a short distance in order to be engaged or disengaged.
In one embodiment of the invention, a closure system is provided that includes first and second longitudinally-extending shell members or closure elements having first and second flanges, respectively. The first and second flanges each have an inner and outer surface such that, in a closed state, the inner surfaces contact one another to form at least one longitudinal seam. A plurality of longitudinally extending ramp pairs are disposed on the outer surfaces of the flanges. A first ramp of each ramp pair is disposed on the outer surface of the first flange and a second ramp of each ramp pair is disposed on the outer surface of the second flange. The plurality of ramp pairs are each inclined away from the longitudinal seam in generally opposite directions when viewed along a first axis. The closure is provided with a clamping rail that has an inner surface equipped with a guide channel that interlocks with the plurality of ramp pairs so that the first and second flanges compress the seam. The guide channel has a shape that at least in part is a negative replica of a longitudinal profile of the plurality of ramp pairs. The guide channel may be provided with a lip along part of its length so that, after the clamping rail is inserted onto the seam and moved in a direction parallel to the seam, the lip engages the engagement elements and prevents the clamping rail from being displaced in a direction radial to the seam.
In a related embodiment, the closure system includes a second plurality of longitudinally extending ramp pairs disposed on the outer surfaces of the flanges. A second clamping rail is also provided which has an inner surface that includes a second guide channel which interlocks with the second plurality of ramp pairs. The second guide may also be equipped with a lip which engages the ramp pairs. The second plurality of ramp pairs may each be inclined away from the longitudinal seam when viewed along a second axis that is opposite to the first direction. In some embodiments, the first and second clamping rails are equipped with a locking mechanism for locking the clamping rails together.
In yet another embodiment of the present invention, third and fourth flanges are provided which form a second longitudinally extending seam located along an edge of the shell members opposite the first longitudinal seam. A third plurality of longitudinally extending ramp pairs are disposed on the outer surfaces of the third and fourth flanges at a location defining the second seam. A third clamping rail is provided that has an inner surface that includes a third guide channel interlocking with the third plurality of ramp pairs. This embodiment may further include a fourth clamping rail that has an inner surface that includes a fourth guide channel which interlocks with a fourth plurality of ramp pairs.
In another aspect, the present invention relates to a clamping element which is particularly useful with closure systems of
Black Michael L.
Blankinship Jenny L.
3M Innovative Properties Company
Fonseca Darla P.
Kim Harry C.
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