Patent Application
20100003864
The present invention is directed to electrical cable connectors and more particularly to wedge connectors for electrically commoning and mechanically securing two electrical cables, such as those used in electrical distribution networks.
In electrical systems it is occasionally necessary to tap into an electrical distribution network, such as connecting an overhead power line to a home or business. One known system for tapping into an electrical distribution network is to use what is commonly referred to as a wedge connector, which includes a C-shaped body member and a wedge. Two cables are electrically commoned and mechanically secured by being pressed into and against interior curved surfaces or channels provided in the C-shaped body member by the wedge, which is driven longitudinally into the body member between the cables.
Sometimes also referred to as Universal Distribution Connectors (or UDC connectors), such wedge connectors are widely used in connecting cables of various sizes (i.e., diameter) for electrical distribution. However, current wedge connectors suffer from the drawback that they are effective over a relatively narrow range of relative cable sizes, requiring many different size wedge connectors.
These and other drawbacks are found in current wedge connectors.
What is needed is a wedge connector that provides for connection of cables over an extended range of relative cable sizes.
According to an exemplary embodiment of the invention, a wedge connector is disclosed. The wedge connector comprises a C-shaped body member having sides converging toward a first body member end from a second body member end and having edges formed to define a pair of inwardly facing channels along respective sides connected by a web extending between the channels. The connector also comprises a wedge having sides converging toward a first wedge end from a second wedge end to be conformably received in the C-shaped body member. The wedge has concave, outwardly facing surfaces on each side connected by a web extending between the sides and a spring rib formed in the wedge web. The spring rib extends continuously from the first wedge end toward the second wedge end opposite the first wedge end. The wedge, when conformably received in the C-shaped body member is positioned to mechanically secure a cable between the inwardly facing channel of the C-shaped body member and the concave outerwardly facing surface of the wedge.
According to another exemplary embodiment of the invention, a wedge connector includes a C-shaped body member having sides converging toward a first body member end from a second body member end and having edges formed to define a pair of inwardly facing channels along respective sides connected by a web extending between the channels. The channels have extensions that diverge rearwardly away from the second body member end. The connector further includes a wedge having sides converging toward a first wedge end from a second wedge end to be conformably received in the C-shaped body member. The wedge has concave, outwardly facing surfaces on each side connected by a web extending between the sides, the wedge further having a single spring rib formed in the wedge web, the spring rib extending continuously from the first wedge end toward the second wedge end. The wedge, when conformably received in the C-shaped body member, is positioned to mechanically secure a cable between the inwardly facing channel of the C-shaped body member and the concave outwardly facing surface of the wedge.
In some embodiments, one or more of the cable receiving surfaces of the connector are coated with a dry film lubricant.
An advantage of certain exemplary embodiments described herein is that a single wedge connector can be used across a greater variety of cable diameters than is currently available.
Another advantage is that the ability to expand the range of cables is achieved without the need to substantially increase the thickness of the connector components, and thus without increasing material costs.
Other features and advantages of the present invention will be apparent from the following more detailed description of exemplary embodiments, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.
a and 5b are perspective views of a wedge connector having a pair of cables secured therein illustrating the ability to accommodate a large range of cable diameters.
Where like parts appear in more than one drawing, it has been attempted to use like reference numerals for clarity.
As shown in
The body member 12 and wedge member 14 may be constructed from any electrically conductive material such that a pair of cables secured together with the wedge connector 10 are electrically common. In one embodiment, each of the body and wedge members 12, 14 are formed of tin-plated copper alloy. The body and wedge members 12, 14 can be produced by stamping and forming.
Edges 32 of the C-shaped body member 12 are rolled in or otherwise configured to form inwardly facing channels 34 that are joined by a body member web 38 extending between them. The channels 34 and body member web 38 together define a space 40 for receiving the wedge 14. In the embodiment illustrated, the channels 34 are of equal size, but could be of unequal size. In another embodiment, as shown in
As better seen with reference to
The wedge 14 further includes a spring rib 50 formed in the wedge web 58 that generally extends in a longitudinal direction from the first wedge end 26 toward the second wedge end 30. The spring rib 50 protrudes from the web surface so as to be positioned within the space 40 defined by the body member 12 when the wedge 14 is conformably received in the body member 12 of the connector 10. The spring rib 50 is continuous along its length, although its dimensions may vary over that length. Preferably, the spring rib 50 is tapered such that the width of the spring rib 50 gradually decreases as the distance from the first wedge end 26 increases, as illustrated. That is, while the tubular members 20 of the wedge 14 converge toward the first wedge end 26 from the second wedge end 30, the spring rib 50 conversely converges toward the second wedge end 30 from the first wedge end 26.
The spring rib 50 extends toward, but generally does not extend to, the second wedge end 30. The spring rib 50 ordinarily extends at least one half the length of the wedge web 58. Where the wedge 14 contains a feature 60 at or near the second end of the wedge 14, the spring rib 50 may extend to the feature 60, which ordinarily projects from a surface of the wedge web 58 opposite that of the rib 50.
The use of a single spring rib 50 in this manner provides an advantage in that the spring rib 50 provides sufficient resilience to resist deformation of the wedge 14 and thus provide sufficient retention force when the connector 10 is used with smaller diameter cables. Conversely, the spring rib 50 still provides sufficient strength when flexed to accept larger cables without increasing the size or thickness of the connector components. The spring rib 50 also helps prevent rolling and/or buckling of the wedge side members 20. The wedge 14 may include multiple spring ribs.
Cables 66 are secured in the connector 10 by driving the wedge 14 into the C-shaped body member 12 between the cables 66, which are compressed between the channels 34 of the body member 12 and the outwardly facing surfaces 54 of the wedge 14. Securing can ordinarily be accomplished, for example, with a pair of adjustable pliers. The conductive nature of the connector 10 has the combined effect of both securing the two cables 66 and making them electrically common.
In one embodiment, the cable-contacting surfaces of either one or both of the body member 12 and wedge 14 can be coated with a dry film lubricant to aid the user with insertion of the wedge 14 into the body member 12. Any known dry film lubricant, such as graphite, for example, can be used. Preferably, at least the wedge's concave outwardly facing surfaces 54 are coated with the dry film lubricant.
As the wedge 14 is being pressed into space 40, the sides 16 of the C-shaped body member 12 are resiliently forced outwardly to provide a continuing compressive force on the cables 66. An equal counterforce is applied against the outwardly facing surfaces 54 of the wedge's tubular edge members 20, some of which is alleviated by compression of the spring rib 50, which distributes the force throughout the wedge web 58.
Where a locking mechanism is employed, such as the illustrated feature 60 and aperture 46 combination, the two components of the locking mechanism can be positioned such that the wedge 14 has reached the correct insertion depth when the feature 60 enters the aperture 46. The wedge web 58 deflects slightly as feature 60 slides over the body member web 38 of the C-shaped body member 12 and rebounds to drive the feature 60 into the aperture 46 sharply.
As shown, the wedge 14 is symmetric and the outwardly facing concave surfaces 54 on the edge members 20 are formed so that each can accommodate a cable of identical gauge. Alternatively, the wedge 14 could be formed asymmetrically, having tubular edge members 20 and corresponding surfaces of different size to accommodate a cable on one surface of a diameter different than that of the other surface.
As best seen in
Turning to
In one embodiment, the connector 10 can be used for connecting two cables having a diameter in the range of about 16 mm to about 21 mm. Alternatively stated, a single connector 10 in accordance with an exemplary embodiment having a single spring rib 50 and channel extensions 42 can replace the three separate connectors currently needed for this cable range (e.g., UDC connector Types VI, VII, and VIII). This range is by way of example only and it will be appreciated that other ranges of cable diameters may be accommodated with other embodiments.
The angles at which the body member 12 and wedge 14 converge may be the same or different. In one embodiment, each side 16 of the body member 12 has an angle of about 5.5 degrees, each of the side members 20 of the wedge 14 has an angle of about 7 degrees. As a result, the wedge 14 converges slightly more sharply than the body member 12, which can provide for better performance in helping the wedge travel from the initial to the locked position when the connector 10 is used with larger diameter cables.
While the foregoing specification illustrates and describes exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.
