Description:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention is directed to the field of connecting devices and principally to an improved means and method for establishing a splice connection between two or more articles.
2. Description of the Prior Art
Various prior art cold flow methods have been devised to connect a sleeve or collar about relatively nondeformable rigid articles such as steel rods or the like to overcome the difficulties encountered when attempting to compress the collar or sleeve radially inwardly in the usual manner. The inherent resiliency of the collar or sleeve tends to cause spring-back of the connector material after removal of the compressive force, resulting in a loose joint between the article and the sleeve or collar. Examples of such prior art methods are disclosed in U.S. Pat. No. 2,102,325 issued Dec. 14, 1937 to J. Klystra; U.S. Pat. No. 2,476,731 issued July 19, 1949 to W. Hobbs, Jr; and U.S. Pat. No. 3,551,999 issued Jan. 5, 1971 to S. Guttman. Two of the aforementioned references pertain to a method of establishing a butt joint between two rigid articles, while the third reference utilizes a cold flow method to compress a collar about a loose bundle of stranded wires. In many electrical applications, however, it is desired to provide a parallel splice connection between either two relatively nondeformable members such as steel ground rods or the like, or a steel ground rod and a relatively deformable copper or aluminum conductor. These members are generally located at the workplace in such manner as to preclude the use of a butt splice, and are further generally sufficiently remote from a workshop as to limit the availability of the special tools and dies required to effect such prior art crimping methods.
SUMMARY OF THE INVENTION
The invention overcomes the difficulties and limitations noted above with respect to prior art devices by providing a unique method and means for establishing a parallel splice connection between two members either of which may be relatively nondeformable. The members are inserted within appropriately proportioned juxtaposed chambers in a deformable connector and the assembly subjected to a localized compression force applied generally intermediate the chambers and of sufficient magnitude as to cause at least a portion of the material forming the walls of the chambers to be both peripherally displaced towards the line of application of the compression force and contracted about the contained members. The die means for effecting such closure comprises in one embodiment, a pair of opposingly disposed, tapered members selectively contoured to provide suitably directed forces against the outer surface of the connector at the line of application. In a further embodiment, the die means is constructed so as to apply a localized compression force along two lines selectively spaced from one another and generally flanking a chamber opening, each force being applied generally tangential to the interior wall of the chamber. It is therefore an object of this invention to provide an improved method and means for effecting a parallel splice connection.
It is another object of this invention to provide an improved crimping method.
It is a further object of this invention to provide a method and means for establishing a reliable and secure parallel splice connection between two relatively nondeformable elongate articles.
It is yet another object of this invention to provide a method and means for peripherally displacing the wall material of a deformable orificed connector about one or more rigid, nondeformable elongate articles. It is still another object of this invention to provide a method and means for joining a steel grounding rod to an electrical conductor.
other objects and features will be pointed out in the following description and claims and illustrated in the accompanying drawings which disclose, by way of example, the principle of the invention and the best modes contemplated for carrying it out.
BRIEF DESCRIPTION OF THE DRAWINGS.
In the Drawings:
FIG. 1 is a fragmentary perspective view, partly in section of an assembly comprising a dual chambered connector in which are disposed elongate articles preparatory to establishing a parallel splice connection in accordance with the concepts of the invention.
FIG. 2 is a fragmentary front elevational view, partly in section, showing the assembly of FIG. 1 disposed between a die set in accordance with the concepts of the invention.
FIG. 3 is a fragmentary front elevational view, partly in section, showing a further step in the formation of a parallel splice in accordance with the concepts of the invention.
FIG. 4 is a fragmentary front elevational view, partly in section, of a further embodiment of a connector for establishing a parallel splice connection in accordance with the concepts of the invention.
FIG. 5 is a fragmentary front elevational view, partly in section, showing the assembly of FIG. 4 being subjected to a compression force in accordance with the concepts of the invention.
FIG. 6 is a fragmentary front elevational view, partly in section, of a further embodiment of die means for forming a parallel splice connection in accordance with the concepts of the invention.
FIG. 7 is a fragmentary front elevational view of the assembly of FIG. 6 showing a further step in the formation of a parallel splice in accordance with the concepts of the invention.
Similar elements are given similar reference characters in each of the respective drawings.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning now to FIGS. 1, 2 and 3, there is shown a connector 20 for practicing the method of the instant invention. The connector 20 is formed from a deformable material such as commonly employed for electrical connectors, which may include copper, brass, bronze, aluminum and other like highly conductive materials.
A first chamber 22 and a second chamber 24 extend generally longitudinally through the connector 20 in juxtaposed relationship and communicate with one another along a longitudinally extending slot 26. For purposes of illustration, the first chamber 22 is shown as having a larger opening than the second chamber 24, although it should be understood that the chambers may be similarly dimensioned, if necessary or desirable, without departing from the spirit of the invention and within the concepts herein disclosed. To further illustrate the method of the invention, there is shown a solid, nondeformable rod-like member 28 inserted within the first chamber 22 and a stranded electrical conductor 30 inserted within the second chamber 24. The relative proportions of the first and second chambers 22 and 24 are chosen so as to provide a relatively close fit about the respective elements 28 and 30. The assembly is then selectively located between a pair of opposingly disposed die members 32 and 34, respectively, each comprising a jaw member 36, 38 having a tapered end 40, 42 respectively, so that the tapered ends 40 and 42, which lie along a common axis, engage the connector 20 generally intermediate the first and second chambers 22 and 24, respectively, substantially as shown, and preferably flank the slot 26. Each of the tapered ends 40 and 42 is defined by a first inclined surface 44, 46, and a second inclined surface 48, 50, communicating with one another at a preferably slightly rounded apex 52, 54. The surfaces 48 and 50 are each angularly offset from the longitudinal axis of its respective die member 32, 34, so as to lie preferably closely against the adjacent surface of the connector 20. The die members 32 and 34 are then urged towards one another in the direction indicated by the arrows 56, 56' in FIG. 3. Accordingly, the generally tangential component of the forces applied by the die surfaces 48 and 50 against the adjacent surfaces of the connector 20 cause a peripheral displacement of the connector material surrounding each of the chambers 22 and 24 towards the line of application of the compressive die forces generally in the direction shown by the arrows 58, 58' surrounding the first chamber 22, and the arrows 60, 60' surrounding the second chamber 24. This displacement is due to the ability of the material comprising the connector 20 to cold flow under suitable pressure. The wall at least of the chamber 22 is thus caused to be moved into firm intimate contact with the outer surface of the rod 28. Since substantially no compression of the major part of the chamber wall has taken place, the problem of spring-back of the chamber is thus effectively eliminated so that a secure permanent joint is formed between the wall of the chamber 22 and the rod 28. The wall of the chamber 24 is similarly subjected to cold flow to cause peripheral displacement of at least a portion of the material forming such wall and a certain degree of contraction of the opening of the chamber 24. However, the longitudinal component of the compressive forces applied by the die members 32 and 34 cause a closure of the slot 26 which tends to further contract the wall of the chamber 24 about the conductor 30 to effect a second secure joint thereat. Additional peripheral displacement of the chamber wall material may be accomplished in a similar manner by providing modified die members such as 62 and 64 shown in FIGS. 6 and 7. Each of the die members 62 and 64 comprises a pair of jaw members 66, 68 and 70, 72, respectively, each jaw member having a contour essentially duplicative of the jaw members 36 and 38 described above with respect to the embodiment illustrated in FIGS. 2 and 3. The jaw members 66 and 68 each terminate at an apex 74, 76, respectively, and the jaw members 70 and 72 each terminate at an apex 78, 80, respectively. The die members 62 and 64 are essentially identically configured and the spacing D between each pair of apexes is chosen so that, upon placement of the connector 20 therebetween with the jaw members 66 and 70 located intermediate the first and second chambers 22 and 24 in the manner indicated above with respect to FIGS. 2 and 3, the apexes of the jaw members 68 and 72 will contact the outer surface of the connector 20 along an axis A substantially tangent to the chamber 22. As the die members 62 and 64 are urged together in the direction indicated by the arrows 82 and 84 in FIG. 7, the wall material encompassing the chamber 22 in the general area of the apexes 74 and 78 of jaw members 66 and 70, respectively, will be peripherally displaced in the direction indicated by the arrows 86, 86', while the wall material encompassing the chamber 24 in the same general area of the apexes 74 and 78 will be peripherally displaced in the direction indicated by the arrows 88 and 88'. Additionally, the wall material encompassing the chamber 22 in the general area of the apexes 76 and 80 of the jaw members 62 and 64, respectively, will be peripherally displaced in the direction indicated by the arrows 90 and 90'. Accordingly, although the chamber 24 is subjected to substantially the same forces described above with respect to the embodiment illustrated in FIGS. 2 and 3, the chamber 22 is subjected to additional forces applied by the jaw members 68 and 72 to further increase the engagement between the connector 20 and the rod 28 due to the additional cold flow of the connector material.
Referring now to FIGS. 4 and 5, there is shown a connector 92 similar to connector 20 with respect to the physical characteristics thereof, but differing, however, in its construction in that the connector 92 is provided with two discrete longitudinally extending, juxtaposed chambers 94 and 96 separated from one another by a solid web portion 98. This arrangement has been found advantageous where it is desired to provide a parallel splice connection between two relatively nondeformable rigid rods such as the rod 28 shown disposed within the chamber 94 and a furthr rod 100 shown disposed within the chamber 96. The connector 92 is positioned between the jaw members 36 and 38 of the die members 32 and 34 in essentially the same position as the connector 20, that is, with the tapered ends 40 and 42 of the jaw members 36 and 38, respectively, located generally intermediate the two chambers. The die members 32 and 34 are then urged together with sufficient force in the direction indicated by the arrows 56 and 56' as to cause the peripheral displacement of the material forming the walls of the chambers 94 and 96 in the direction indicated generally by the arrows 101, 101' and 102, 102' in FIG. 5. The resulting cold flow of the connector material about each of the rods 28 and 100 thus established a firm gripping action between the interior surfaces of the chambers 94 and 96 and the respective exterior surfaces of the rods 28 and 100. In this case, however, the web portion 98 is compressed under the influence of the longitudinally directed component of the forces generated by the die members 32 and 34, and a partial extrusion takes place, whereby the web portion 98 elongates slightly generally in the direction indicated by the arrow 104 in FIG. 5, causing a further peripheral displacement of the material of the wall surrounding the chamber 96 and a corresponding increase in the interfacial engagement between the rod 100 and the interior surface of the chamber 96. The contraction of the chambers 94 and 96 about the respective rods 28 and 100 is thus accomplished by cold flow of the surrounding material in essentially the same manner described above with respect to the embodiment illustrated in FIGS. 2 and 3. It should be further noted that the die members 62 and 64 shown in FIGS. 6 and 7 may be employed in conjunction with connector 92 to provide additional cold flow of the material forming the wall of the chamber 94 in essentially the same manner as described above with respect to connector 20. It should also be noted that although each of the jaw members 36, 38, 66, 68, 70, and 72 is contemplated as having a depth substantially equal to the width of the connector 20 or 92 so as to provide a continuous line of contact therewith, the jaw members may be selectively recessed or relieved in the area of the apex thereof at one or more discrete intervals along the length of the apex to selectively concentrate and direct the forces applied by the die members against the outer surfaces of the connectors 20 and 92.