US3469020A - Electrical spider connection - Google Patents

Description

Sept. 23, 1969 c, BROOM ET AL ELECTRICAL SPIDER CONNECTION Filed Dec. 6, '1965 all!!! By 3466!," k

INVENTOR. ,fl, 3400M 1%.777/[46' United States Patent 3,469,020 ELECTRICAL SPIDER CONNECTION Charles M. Broom, Coral Gables, and Robert H. Stevens, Miami, Fla., assignors to Kearney-National Inc., St. Louis, Mo., a corporation of Delaware Filed Dec. 6, 1965, Ser. No. 511,648 Int. Cl. H02g 3/28, 15/08 U.S. Cl. 17471 9 Claims ABSTRACT OF THE DISCLOSURE A device for facilitating the making of electrical connections in tight places between a main line conductor and a multiplicity of branch circuit lines wherein a multiplicity of relatively short pieces of insulated conductor, long enough to reach out of the tight place, all have an end barren of insulation permanently mechanically and electrically connected together with a line conductor terminal and the junction embedded in insulation.

buildings.

The present novel spider connection provides a rigid hermetically sealed connection that develops the full potential strength of the conductors; i.e., the connection will hold under a tension that causes the individual conductors to fail. The spider connection may be made using the main feeder conductor and the multiple branch circuits as the legs of the spider, whereby additional splicing is avoided. Alternatively, the spider may be fabricated in the 'shop and later spliced into the main and branch circuits using methods commonly known to those skilled in the art.

An object of this invention is to provide an insulated electrical connector having improved means for connecting a multiplicity of branch circuits to a common supply. "Another object of this invention is to provide an improved connector having superior mechanical and electrical capabilities that can be field assembled by the average' workman.

E further object of this invention is to provide a novel and improved electrical connector that is of extremely simple construction, requiring only a minimum of basic materials of construction for fabrication, and which is adapted to be used for wet or dry locations.

Still another object of this invention is to provide an insulated electrical connector that can be' shop assembled using ordinary tools and supplies and which is adapted -toinclude various sizes and numbers of wires and wherein the terminal ends of the Wires provide a junction that is adapted-to connect from a main to a number of branch circuits.

Still'another object of this invention is to provide a '-means for readily connecting a power main to a plurality of branches, especially in the field where the assembling may take place in cramped quarters.

This and other'objects and features of this invention {will be madev more apparentby reference to the follow- 3,469,020 Patented Sept. 23, 1969 ing description taken in conjunction with the accompanying drawings, in which:

FIGURE 1 is a part sectional, part perspective view of an electrical connector illustrating one embodiment of the electrical spider connection.

FIGURE 2 is a top perspective view of the connector of FIGURE 1.

FIGURE 3 is a sectional view of another embodiment of the invention showing a modification of the improved connector of FIGURES 1 and 2.

Looking now in detail to the drawings, wherein like numerals indicate similar elements in the different figures, there is seen in FIGURES 1 and 2 a spider connection 1 comprised of six insulated conductors 3 having metallic wires 5, 6, and 7, each being joined at one end into a rigid terminal connection 2. As best seen in FIGURE 1, the terminal connection 2 comprises the cable bundle, or the six wires 5, 6, and 7 tightly wrapped with wire at several locations, as seen at 8, to form a rigid mechanical connection which is encased in solder. After the solder has sufficiently cooled, the entire spider connection is molded or encased in an epoxy potting compound as seen at 10.

In making the above first mechanical connection, the wires of the individual conductors 3 have been stripped of their insulation as shown at 5, 6, and 7 to present a clean surface that can be suitably soldered with no additional preparation being required. Where a Wire size number 2 is used for the spider conductor 5, 6, and 7, the mechanically wrapped joint or connection may be satisfactorly effected by employing eight turns of number 18 copper wire at four equally spaced positions starting about inch from the end of the connection and completing the wrap about one inch from the end. The insulation is left as illustrated at 16 to provide a hermetic seal between the various conductors.

The mechanical terminal connection is next encased in solder as at 9, using conventional means such as a small mold wherein solder is poured from a ladle into the mold. The surface of the conductor bundle may preferably be tinned prior to soldering, if desired, especially where a high lead content of the solder 9 is used. The molded connection 9, except for extremely large conductors, can be immediately placed in a suitable second mold for the pouring of the epoxy compound 10, since the temperature of the connection 9 will usually have dropped to a suitable value during the preparation of this final step.

During the initial preparation of the individual conductors 3, the insulation at 16 should be roughened by scraping or sanding to permit attaining a bond between the epoxy compound and the insulation. In the specific above example wherein No. 2 wire is used, about /2 inch insulation should be embedded in the epoxy resin. The resin is advantageously poured into a pre-formed uncoated paper mold or into a waxed or Teflon coated paper mold Which may be either left in place as part of the connection means or removed for further use as desired. The epoxy will not bond to a new Teflon" coated mold; but, as the Teflon mold is subjected to abuse and becomes scarred on the inside from repeated use, it becomes more difficult to remove from the spider connection from such a mold and where its presence may prove advantageous the mold may be left as part of the spider connection to offer further protection to the assembly. Dyes may be employed in the epoxy resins to additionally color code the spider connection, which may also have color coded insulation thereon.

3 Where thespider connection of FIGURES l and 2 is to be used to splice into a large cable run, that is a Y or inline splice, that is attached at the midpoint of a cable rather than the end thereof, the two large conductors 6 and 7 may be sized equal to the diameter of the cable run, and two conductors 6 and 7 placed in series with the tapped cable. The inline splice may also be made merely by cutting the main conductor and using each end of the main as represented by conductors 6 and 7, where the spider is made on site in the field. Alternatively, a single larger conductor 6 or 7, FIGURES 1 and 2, may be attached to a line cable as by a so-called H-frame compression connector of ductile metal such as a copper or aluminum, and then insulating the connection in accordance with the principles outlined above.

In the embodiment depicted by FIGURE 3, a copper sleeve 13, with or without an intermediate barrier 12 therein, is employed for accommodating the multiplicity of branch line conductors 5 at one end 14, and for confining one or more main conductors at the other end. The sleeve 13 may be a compression connector which, after assembly therein of the ends of a multiplicity of conductors 5, is compressed about them into a strong mechanical connection with good electrical conductivity. If desired, the connection may be further strengthened by soldering as at 9. Alternatively, the conductors 5 may be welded or otherwise secured in the end 14 of the sleeve with or without compressing the sleeve about the conductors. In any event, after the conductors 5 are suitably mechanically and electrically connected to the sleeve, the connection is preferably encased in an epoxy resin embedment as illustrated at 10 to provide a field assembled or shop assembled spider connection 2. Likewise, the common at aperture 15 may be connected in any suitable way to an incoming main while conductors 3 feed individual circuits or branches as desired. For example, the common at aperture 15 may be compressed onto one or more large incoming service conductors, and, if desired, reinforced as with solder and embedded in insulation resin, as above outlined, depending upon the conditions of its intended use. In fact, the sleeve 13 may itself be the main conductor, or part thereof.

The caps 4 of FIGURES 1 through 3 are left in place to protect the conductors from the deleterious effects of the atmosphere in which they are used. In some circuitry applications, only a portion of the several spider connections may be initially used, hence the remaining spider conductors will be available for future use, as occasion demands, by merely removing the cap and making a straight splice type connection, such as by employing an H-frame or sleeve type compression connector or other conventional branch with adequate insulation for the particular usage.

' Regardless of the manner in which the component main and branch conductors are mechanically and electrically connected together into the spider, the legs, e.g., conductors 5, 6, and 7, are of no greater length than will be convenient for a lineman to handle and install, and such will ordinarilymean the legs, whether large or small, be of length no greater than about four feet.

I The epoxy resin referred to herein is basically the same type material used in the more advanced type insulation of motor coils, condensers, transformers, and the like, and one suitable resin employed was found to have the following properties:

Flexural modulus of elasticityp.s.i. (5.92)(l Tensile strength p.s.i 8,500 Compressive strength p.s.i 23,000 Dielectric const. at 60 c.'p.s 2.93 Specific gravity 1.11

Corp. formula HU-l65 is suitable, as is ordinary fiberglass resin, like that used in the re'pair'of boats where fiberglass textile is built up using the resin.

It is now evident that each of the above novel spider connections offers an inexpensive means of supplying several branch circuits from a single service conduit, wherein the spider connection also provides a field assembled connector that is strong both electrically and mechanically, and will additionally provide a moisture proof insulating seal. The insulation of each conductor is locked together in a plastic resin'that protects the connection from the surrounding atmosphere, and is suitablefor use in splicing applications including'those exceeding the 7.5 kv. service so long as proper precautions are taken to insure that adequate insulation is provided by selecting the proper thickness of the resin insulator.

It should now be evident that the several improved resin splices outlined above can be applied with equal ease to a wide variety of straight or branched connections in both power and communication cables, where the size and thickness of insulation can be adjusted to match the severity of environment. The use of these procedures permits normally difiicult splices to be accomplished at the job site even in restricted working quarters.

Having thus described the invention, what is claimed and desired to be secured by Letters Patent is:

1. An electrical spider connection comprising-a multiplicity of separately insulated branch conductors mechanically and electrically connected at a common junction, said branch conductors having an individual length from said junction of not substantially greater than four feet and together forming a short length of multiple stranded cable in which the individual strands are insulated from each other save at said junction, means forming a layer of insulation completely covering said junction, and a main conductor projecting from said junction beyond the exterior of said means.

2. The spider connection of claim 1 in which the individual conductors are provided with a uniform coating of electrical insulation about their exterior surface, said insulation extending into said means a sufiicient depth to provide an hermetic and mechanical connection between adjacent conductors.

3. The spider connection of claim 2 in which the end of the multiplicity of conductors within said .junction each abut a common plane and are rigidly fastened by multiple turns of copper wire tightly wound about the outer periphery of the connected ends and embedded in solder.

4. The spider of claim 2 in which the multiplicity of conductors are comprised of two. groups of individually insulated conductors, one group consisting ofat least one conductor, and the other group consisting of more than one conductor, each conductor in the former group having a cross sectional area equivalent to thetotal cross sectional area of the conductors in the latter group.

5. The spider connection of claim 2 wherein said common junction includes a metallic sleeve defining first-and second connection sockets, said branch conductors being crimped into said sleeve at said second connection socket, whereby said first connection socket may be connected to a main service supply and saidmultiplicity of conductors may be used to supply several branch circuits.

6. The spider of claim 5 in which the, ends ofsaid branch conductors furthest removed from the said; common junction are each provided with a plastic cap seal means to thereby hermetically seal the conductor.

7. The spider of claim 2 in which said means forming a layer of insulation is an epoxy resin confined in-a cupshaped poly tetra fluoro ethylene coated paper container having a depth and diameter of a value to entirely enclose said soldered connection.

8. The spider of claim 2 wherein the means forming a layer of insulation includes an embedment of plastic insulation about said permanent electrical and mechanical 6 connection, and at least some of the insulation on said References Cited $211523? branch conductors being embedded in said em- UNITED STATES PATENTS 9. The spider of claim 1 wherein said common junc- 2,905,918 9/ 1959 Wagnertion includes a metallic sleeve, crimped onto said conductors said branch conductors being crimped onto said 5 DARRELL CLAY Pnmary Exammer sleeve at said connection means, whereby said sleeve may U 8 C1 X R be connected to a main service supply and said multiplici'ty of branch conductors may be used to supply several 17487, 90; 29628 branch circuits. 10

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