US2058929A

US2058929A - Cable splice connecter

Info

Publication number: US2058929A
Application number: US756579A
Authority: US
Inventors: Elmer R Vietzen
Original assignee: Individual
Current assignee: Individual
Priority date: 1934-12-08
Filing date: 1934-12-08
Publication date: 1936-10-27
Anticipated expiration: 1953-10-27

Description

0t.27',1936. E. R. WE1-ZEN 42,059,929

CABLE SPLICE CONNECTER Ot. 27, 1936. E; R WE1-ZEN l 2,058,929

CABLE SPLIGE CONNECTER Filed Dec. 8, 1934 2 sheets-sheet 2 jfg, 3,

Patented Oct. 27, 1 936 UNITED STATES PATENT OFFICE 6 Claims.

This invention relates to cable splice connecters, and more particularly is directed to the splicing of cable in ducts where limitations of space impose practical restrictions upon the formation of such cable splices.

It has been customary practice, in making splice connections between two adjacent ends of multiple conductor cable for transmission lines and the like, to lace and solder the copper strands of each conductor together to make the splice. This required considerable time and did not provide a joint of the desired low resistance.

The use of straight splice copper connecters to fit over the ends of two cable conductors, joining them together, has been employed in making cable joints outside of conduits where no limitations as to the external diameter of the joint are imposed. However, such practice has not, to my knowledge, ever been employed in the splicing of conductors for use within a conduit.

I propose to provide a cable splice connection of low resistance in which the quantity of copper carrying current through the joint is substantially the same as the copper in the conductor itself, whereby the resistance of the joint is not increased to any substantial extent over the resistance in the conductor itself.

In carrying out the proposed invention, it is contemplated that the adjacent ends of the conductor will be tapered inward-ly to form, in effect, a pair of oppositely extending conical surfaces. Over the two tapered ends of the conductors is provided an annular copper connecter, or splice, the internal form of the connecter corresponding to the lateral surfaces of the adjacent conductor ends. Thus as the cross-sectional area of the copper in the vconductor decreases, the crosssectional area of the connecter increases, so that the total cross-sectional area of copper remains substantially constant throughout the splice or joint. Also, due to the relatively large lateral .surface of the tapered end of the conductor, low resistance lateral connection to the connecter can be obtained, thus maintaining the resistance at the joint at a minimum.

Thus I produce a connection of no greater external diameter than the diameter of the conductors, and which provides a cross-sectional area of copper substantially equal to the copper area of the conductor, with a large lateral contact surface between the conductors and the connecter which reduces the resistance at the joint.

In practice, however, stranded copper conductors are usually employed in transmission lines, and the invention, in its preferred form, is carried out by cutting away the outer ring of strands of the conductor at a point spaced rearwardly a slight distance from the ends of the conductors, and providing the approximation of the tapered construction by cutting away the next ring of conductors at an intermediate point, the sleeve or connecter being correspondingly reduced in internal diameter while its external diameter remains substantially constant and equal to the external diameter of the conductor. It is to be understood that this procedure may be continued by successive cutting of the annular rings of strands in order to approach, as nearly as possible, a true tapered end for the conductor, but inV practice I find that the successive cutting of one or two of the outer rings of strands is suilicient.

It is an essential requirement, in splices of conductors adapted to extend through conduits or ducts, that the external diameters of the splices or joints be maintained as close to the external diameter of the conductor as possible, since relatively small clearance between the cable and the conduit is provided. The present invention provides a construction wherein'the external diameter throughout the splice remains substantially the same as the external diameter of the conductor, so that even with a three-phase conductor cable, the external diameter of the cable where spliced, will still allow the cable to be drawn through a conduit or duct.

Another object of the present invention resides in the provision of a cable splice connecter which is of low resistance, comparing favorably with the resistance of the conductor itself.

A still further object of the present invention is to provide a splice connection of this type which may be easily applied, and which considerably reduces the time required to effect splicing of two lengths of cable.

One of the major advantages of the present inventiony resides in the provision of a splice which is of simple and economical design, possesses maximum current-carrying capacity, and which is easily applied and may be adapted for use upon various sizes and types of conductors.

Other objects and advantages of the present invention will appear more fully from the following detailed description, which, taken in connection with the accompanying drawings, will disclose to those skilled in the art the particular construction and method of application of a preferred form of the present invention.

In the drawings:

Figure 1 is a diagrammatic view illustrating the underlying principles of the present invention;

Figure 2 is a sectional view taken through a splice in a three-phase conductor for use in conduits or the like;

Figure 3 is a detailed sectional view of a conductor splice, such as shown in Figure 2;

Figure 4 is a, sectional view illustrating a modifled form of splice; and

Figure 5 is a sectional view taken substantially on line 5-5 of Figure 2, showing a completed splice formed in accordance with the present invention.

Referring now in detail to Figure 1, l have illustrated two conductors, B and 1, which, as shown in dotted lines, are normally of cylindrical form and of uniform external diameter.

The adjacent ends of the conductors E and 1 are tapered as indicated at B and 9, respectively, to provide smooth conical surfaces extending sub-- stantially to the end of each of the conductors. Over the tapered ends of the conductors 6 and 1 is disposed a splice or connecter Il), preferably having relatively thin cylindrical portions I2 and I3 extending over the outer external surfaces oi! `the conductors E and 1 beyond the tapered por tions thereof. The member i0, as shown, is pro.n vided with an inwardly extending annular sur face providing two outwardly flaring conical sunl faces adapted to engage the conical surfaces B and 9 of the conductors 5 and 1. The splice member IIJ is preferably formed of annealed copper tubM ing, which is drilled and shaped to the form shown, and, preferably, the lateral surfaces oi the conical portions 8 and 9 are provided with a flux so that solder or the iilre may be poured between these surfaces and the interior surface of `the member I in ord'er to provide a positive electrical connection therebetween,

It will be noted, in this diagrammatic show ing, that as the cross-sectional area of copper in the conductors 6 and 1 decreases toward the joint, the cross-sectional area of copper in the splicing member IIJ correspondingly increases, so that the total crosssectional area at the joint remains substantially constant throughout the splice. Thus, if the conductors 6 and 1 are of the same size, the area of copper which carries current in the conductors is continued throughout the joint, so that no reduction in current carrying capacity is introduced by reason of the splice. The crosssectional area. of the member Ill, midway between its ends, is equivalent to the cross-sectional area of one oi the conductors, such as the conductor or 1. Further, because of the relatively large lateral surfaces 9 and 9 of the conductors, and the soldered connection to the interior surface of the member I0, good electrical connection is ef fected laterally from the conductors to the member I0, and since this area is substantially larger than the cross-sectional area of the conductors, a splice or joint of minimum resistance is provided. Further, it should be noted that the external periphery of the conductors 6 and 1 is not materially increased` by reason of the splice therebetween, since the extending portions I2 and I3 of this member may be eliminated, insofar as the particular invention is concerned.

Referring now in detail to a practical application of the present invention, I have disclosed, in Figure 2, two lengths of armored cable indicated at I and I9, respectively. The armored cable comprises a lead sheath, or similar armored sheathing, within which is provided a wrapping oi' tape, called a. wrap belt, which is indicated at I1 and which serves to hold the three conductors I8, I9 and 20, shown in Figure 5, in position.

Each of the conductors IB, I9 and 29, is separately wrapped with tape, as shown at 22, and, at a point spaced rearwardly approximately three or four inches from the end of the conductor, the tape is removed or pared down, as shown at 23. to provide a. smooth taper leading to the external surface of the bared conductor I9. The conductor I9 is composed of a plurality of annular rings of copper strands, the entire conductor comprising a large number of `there strands. The outer ring of strands, indicated ai', M, is re moved a short distance outwardly from the tapered portion 23 of the tape 22, and intermediate the ring o strands 24 and the end. T25 of the conductor i8, the second outermost ring of strands, shown at 26, isalso removed, giving a substantially stepped formation at the end of the conductor, which, practically, provides a tapered end portion ior the conductor.

The conductor 21, extending from the cable I8, is prepared in the same manner, and the two adjacent ends of the conductors I5 and 21 are brought into approximate abutting engagement.

Prior to splicing the conductors together, however, a lead sleeve, shown at 28, is slipped rearw-ardly over one of the' cables, such as the cable it, and moved rearwardly upon the cable so `that the exposed ends of the conductors It, l5 and are exposed. Over each of the extending portions of the conductors I8, iB and is then slipped an annealed copper sleeve or splicing con nectar, shown in detail in Figure 3 at This member is prefer-ably split to allow :for expansion and contraction thereof due to varian tions in the diameter of the cable7 the surface being .shown at 32. The end portion oi" the sleeve is of an internal diameter adapted to fit over the second annular ring of strands 25, and is adapted to have substantially abutting engagernent with the outermost ring of strands 2l. Preferably, a beveled connecting portion 33 is provided between the central internal surface of the sleeve 30 and the outer end surfaces, in

order to prevent spreading of any ci the strands of the conductor and to wedge the same into tight engagement.

The strands of the conductor I9, prior `to insertion of the sleeve 30 thereover, are preferably provided with a coating of flux or the like. and after the sleeve has been positioned thereon, the opposite conductor 21 is slipped into the opposite end of the sleeve or connecter 30, the conductor 21 being preferably first coated with a flux in a manner similar to that described in connection with the conductor I9. After the conductors I9 and 21 have been positioned within opposite ends oi' the connecter 30, as shown in Figure 3, solder is poured through the groove or split portion 32 of the connecter 3U, and runs into the interstices between the strands of the conductors I9 and 21, into the tapered spaces formed by the tapered portions 33 in the interior of the conductor III adjacent the ends of the ring of strands 2l, and about the ends of the sleeve I9 and the adjacent strands of the conductors I9 and 21. Solder is poured into this space, and into the space between the ends of the conductors I9 and 21, alternately with fiuxing material, and as the splice illls with solder, a portion of the solder overruns the ends of the connecter 30 and outwardly of the groove or split 32. This solder is allowed to assume a paste-like form, and is then wiped and smoothed over to provide a smooth exterior sur face extending from the wrapping 23 of the conductor I9 along the outer ring of strands 24, the sleeve 30, the outer ring of strands Il of the conductor 21, up to the wrapping 35 of this conductor.

The solder having been provided and filling all nterstices between the connecter 30 and the conductors I9 and 21, the entire splice is then wrapped with half-lapped layers of tape over the exposed strands to the surface of the connecter and the opposite strands 2l of the conductor 21,.

(ifi

The wrapping of this tape is alsoy continued, with reduced thickness, over the

tapered portions

23 and 35 of the insulation of the conductors, and rearwardly over the insulated conductors, indicated at 22 and 36, being tapered off and finally merging into the outer insulated surface of Ithe conductors I9 and 21.

Each of the conductors I8, I9 and 20 is spliced in this manner, the tape winding being indicated at 31 in Figure 5 for each of the conductors I8, I9 and 20. The three conductors are then bound together with a layer of tape, the tape being shown at 38 and being wound in such manner as to have gaps 39 between adjacent spirals thereof. This binds the three spliced conductors together, and after this splicing has been completed, the `sleeve member 28 is moved forwardly over the splice, the ends thereof embracing the armored insulation of the cables I5 and I6, and these ends are then turned down, as indicated at 48 and 42, to engage the armored insulation of the cables I5 and I6. The sleeve 28 is then provided with wiped lead joints at its ends, shown at 43 and 44, to secure the same in position upon the armored cables I5 and I6.

The sleeve 28 is preferably provided with a plurality of openings 45 extending into the interior thereof, these openings providing for pouring of insulating compound, indicated at 46, into the interior of the sleeve 28. The insul-ating compound permeates between the spaces in the three conductors, and lls the lead sleeve 28, thus completely insulating the entire splicing connection and driving all air or entrapped gases out of the interior of the sleeve 28. After the insulating compound 46 has entirely filled the interior of the sleeve 28, the openings 45 are closed by lead plugs 48, which are then wiped down to provide a smooth surface over the external periphery of the sleeve.

It will be noted that the provision of the splicing connecters 38 about each of the conductors I8, I9 and 28, joining these conductor lengths to adjacent conductor lengths to provide a longer length of cable, does not increase the external diameter of the individual conductors and thus provides for a splice which may be maintained within the limits imposed by the internal diameter of the conduit through which the cables I5 and I6 are adapted to be drawn or extend. Further, by the provision of the soldered connections along the entire lateral surfaces between the conductor I9 and the interior o-f the sleeve 38, and between the conductor 21 and the interior of the sleeve 38, an efficient lateral electrical connection is provided which will maintain the resistance of the splicing connection at a minimum. By the provision of the successively reduced cross-sectional areas of copper in the conductor I9 as the cnd of the conductor is approached and the correspondingly increased cross-sectional area in the connecter 38, the total cross-sectional area of copper at the splice remains substantially constant, which provides for suilicient copper to maintain the current-carrying characteristics of the conductor at a maximum. The relatively large lateral connecting area between the surface of `the conductor I9 and the interior surface of the connecter 38 provides for efficient electric-al connection therebetween, which, by reason of the solder and flux poured through the split portion of the connecter 38, insures good electrical contact and provides a splice which is the resistance through the conductor.

The splicing construction shown in Figures 2, 3 and 5 is adapted for use with cable conductors of relatively large area, such as conductors of approximately 500,000 circular mil area. For the splicing of smaller conductors, a slightly different construction is provided. Such a construction is shown in Figure 4.

In this figure, two

conductors

58 and 52 are provided, which are adapted to be spliced together. Each of the conductors is provided with a wrapping of insulating tape 53, which is pared down in a smooth taper, as shown at 54, to the bare surface of the

conductors

58 and 52. Between the bared portion of the conductor 58 and its end, the outer ring of strands, indicated at 55, are removed, providing a shoulder portion 56 on the conductor intermediate the ends of the bared portion thereof. Similarly, the outer ring of strands 51 of the conductor 52 are similarly cut off intermediate the ends of the bared portions thereof, providing an annular shoulder 58.

A connecter or sleeve 68 is provided, which is adapted to slip over the end of the conductor 58 and to be moved rearwardly thereon until the tapered portion 62 thereof abuts against the shoulder 56. This provides a wedging action for forcing the individual strands of the outer ring 55 of strands in the cable together to form a more compact cable arrangement. Similarly, the inner strands of the conductor 58 are engaged by the internal surface 63 of the sleeve or connecter 68, and are thus held in position. The conductor 52 is then inserted into the opposite end of the sleeve 68, the tapered portion 62 at the opposite end of the sleeve member 68 similarly forcing the strands 51 into compact circular form. The sleeve mein'- ber 68 is split, as shown at 64, to provide alongitudinally extending opening into the interior of the sleeve. When the

conductors

58 and 52 have been positioned as shown in Figure 4, solder or the like is poured through the slot 64 into the interior of the sleeve, filling the space 65 between the two

conductors

58 and 52, lling the interstices between the individual strands of the conductors, the space between the shoulder 58 and the tapered portion 62 of the connecter, and also extending outwardly along the outer ring of strands 55 and 51 toward the tapered portion 54 of the insulation 53.

Solder and flux are alternately poured through the slots 64 in order to provide an efcient and positive electrical connection between the strands and the internal surface of the sleeve member `68. As the solder begins to cool and assume a pasty form, the outer peripheral edges of the sleeve 68, which are slightly tapered as shown at 66, become coated with solder, and this solder is smoothly wiped up to the insulation 54 to provide a substantially smooth exterior coating of solder between the ends of the sleeve and the insulation 54.

The sleeve member 68, the exposed portions of the

conductors

58 and 52, the tapered portion 54 of the insulation 53, and a small portion of the' insulation 53 are then covered by an insulating tape wrapping, corresponding to the wrapping 31 described in connection with Figure 2. If more than one conductor is provided in the cable, the.

2, 3 and 5. The cross-sectional area of copper for carrying current from the conductor 50 to the conductor 52 remains substantially constant throughout the length of the splice, and the external diam'eter of the splice is not appreciably greater than the external diameter of the cable. At the same time, the contact between the interior surface of the connecter 60 and the strands of the

conductors

50 and 52 provides for good electrical connection therebetween, and because of the relatively large surface which is contacted by the sleeve 6D, the resistance of the splice is kept at a minimum not exceeding, to any substantial extent, the resistance of the conductors.

It will be apparent, in connection with both. embodiments of the invention described, that the length of time to provide a spliced connection such as described will be considerably less than the time heretofore required for lacing and sol-1 dering of the individual copper strands of each conductor, when such splices must be made for conductors extending through conduits or the like. In practice, I have found that the time required is substantially half of the time normally required in the previous practice of lacing and soldering of the individual strands.

Further, the ease with which the connecters 30 and 6U may be slipped over the adjacent ends of the conductors, and the positive means provided for fully insulating and wrapping the splice, prof vide an economical splicing joint of simplified design, which may be readily produced and which serves to provide a splice having a resistance not exceeding, to any substantial extent, the resist ance of the conductors themselves. At the same time, a neat and positive splicing connection is made which greatly increases the current-carry ing characteristics of the spliced connection and also the insulating characteristics of the spliced portion of the cable, while providing a connection which will not become parted during drawing of the cable through a conduit or the like having a limited internal diameter only slightly in excess of the external diameter of the cable.

While I have described and illustrated my invention in connection with standard cable for use in three-phase transmission lines, wherein the cable is to be applied within conduits or the like, I do not intend to limit my invention to the specific types of cable or installations described, but only insofar as defined by the scope and spirit of the appended claims.

I claim:

l. The method of splicing two stranded conductors with a metallic sleeve of an external diameter substantially equal to the external diameter of said conductors which comprises successively reducing the cross sectional area of the conductors toward their adjacent ends, inserting said ends into opposite ends of a tubular sleeve, wedging the intermediate portions of said reduced ends into pressure engagement with the interior of said sleeve, and limiting inward movement of said ends into said sleeve by abutting engagement of the radial end faces of said sleeve with the outermost row of conductor strands of each conductor at the point where the reduced 'cross sectional area of said conductors begins.

2. The method of splicing two stranded conductors with a metallic sleeve of an external diameter substantially equal to the external diameter of said conductors which comprises successively cutting oir the outer rows of strands o! said conductors in a series of steps toward the ends of said conductors to produce a successively reduced cross sectional area of conductor, inserting said reduced ends into opposite ends of said sleeve, wedging the intermediate axial portions of said conductors into pressure engagement with each other and with the internal surface of said sleeve, and limiting inward movement of said conductor ends into said sleeve by abutting engagement between the end faces oi said sleeve and the cut-off end faces of the outermost row of strands of each conductor.

3. The method of splicing two stranded conductors with a metallic sleeve of an external diameter substantially equal to the external diameter of said conductors which comprises suitm cessively reducing the sectional area of said conn ductors toward the adjacent ends thereof, pro viding a sleeve having a generally cylindrical surface of a diameter substantially equal `to the normal diameter of said conductors and having successively increased cylindrical internal sul faces from the center toward the ends thereof joined by outwardly tapered surfaces, inserting the conductor ends into the opposite ends of said sleeve, wedging said conductors inwardly toward the center of said sleeve, and limiting inward movement of said ends by abutting radial engagement between the ends of said sleeve and the strands of said conductors.

4. The combination with two conductors adapted to be spliced in axial alignment and having successively reduced sections towards the adjacent ends thereof, of a splicing sleeve of high electrical conductivity and of an external diameter substantially equal to the diameters of said conductors, said sleeve having success ively increased internal cylindrical surfaces from the center toward the ends thereof joined together by frusto-conical surfaces, the end portions of said sleeve comprising cylinders having an internal diameter such that the thickness of said sleeve is substantially equal to difference in thickness between said condurtors and the flrst reduced sections thereof.

5. As an article of manufacture, a splicing sleeve comprising a cylindrical member of high electrical conductivity having a substantially uniform external diameter and having an internal surface comprising successively increasing cylindrical surfaces from the center toward the ends thereof joined together by frusto-conical surfaces.

6. In combination, a pair of stranded conductors having adjacent ends disposed in axial alignment, the cross sectional area of said conductors being successively reduced toward the ends thereof, a splicing sleeve having an external diameter substantially equal to the diameter of said conductors and having an internal diameter which is successively increased from the center toward the ends thereof, the internal surface of said sleeve having wedging portions forcing the strands of said conductors into pressure engagementwithin said sleeve when the ends of said conductors are inserted into opposite ends of the sleeve, and means forming an inwardly extending radial abutment on said conductors and engaging the ends of said sleeve for limiting movement of said conductors inwardly of said sleeve.

ELMER R. VIETZEN.

Bil