US2773405A - Tool and method for compression splicing of wires and cables - Google Patents

Description

Dec. 11, 1956 r. A. SANDERS ETAL 2,773,405

TOOL AND METHOD FOR COMPRESSION SPLICING OF WIRES AND CABLES Filed April 30, 1953 2 Sheets-Sheet 1 f- INVENTORS moms A. SANDERS FRANK KAHN 'BY W ORN 1'. A. SANDERS ET'AL 2,773,405

TOOL AND METHOD FOR COMPRESSION SPLICING OF WIRES AND CABLES Filed April 30, 1953 2 Sheets-Sheet 2 Dec. 11, 1956 5 R 4/: w w m w E H N 5 m 4 WMK 7 m W 2 O ZEEEE w u n 4 E 3% a m 3 0 3 2:55- 8 a 4 A 1 a 5 -J w .i J n W I 1 2 3 3 United States Patent TOOL AND METHOD FOR COMPRESSION SPLICING OF WIRES AND CABLES Thomas A. Sanders and Frank Kahn, Philadelphia, Pa.

Application April 30, 1953, Serial No. 352,108

6 Claims. (Cl. 81-15) This invention relates to splicing of wires and cables, and more specifically to a tool and a method for splicing ductile wires and cables with pressed connectors.

Splicing of wires and cables used for electrical conductors by inserting them in ductile sleeve conductors and then indenting the sleeve, has proved eminently successful and is rapidly supplanting other splicing means because of the saving of time and labor. In compression splicing of copper conductors of sizes No. 8 A. W. G. and larger with an indenting tool, it formerly was necessary to use a power-operatedtool because the compressive force obtainable with a hand tool even though provided with compound leverage is inadequate to produce a satisfactory indentation. This is particularly true in transversely indenting multiconductor compression splices of the type described in United States Patent 2,467,913, dated April 19, 1949, to Thomas A. Sanders, wherein two or more conductors are arranged in side by side relation within an oval splicing sleeve. The tool illustrated in that patent closes substantially parallel jaws transversely on the sleeve and produces an indentation across the full width of the splice. Experience has shown that a hand tool of this kind capable of satisfactorily indenting copper sleeves and conductors in the larger sizes requires a strenuous effort on the part of the operator, which soon tires him and causes excessive wear on the tool bearings.

As disclosed'in our copcnding application Serial No. 278,426, filed March 25, 1952, We have discovered that it is readily feasible to produce the desired transverse indentation in a sleeve connector by making an initial indentation of relatively very small. area to the desired depth and then advancing the indentation incrementally across the width of the sleeve. The small area of initial indentation permits a deep penetration to be accomplished with a relatively small force, easily applied with a hand tool. This same force is adequate to progressively advance the indentation across the width of the splice no matter how wide.

The hand tool disclosed and claimed in our said application is fully and satisfactorily operative for accomplishing this result as is the tool forming the subject of this application which in some respects may be regarded as an improvement thereon and under certain circumstances may be preferred for making splices of the character in question.

A principal object of the present invention therefore is to provide a novel indenting tool capable of producing an initial indentation of small area in a splicing sleeve or the like and then of incrementally advancing the indentation across the splice to produce a long indentation.

A further object of the invention is to provide a handoperated indenting tool of this character which is light in weight and produces a satisfactory indentation with relatively slight exertion on the part of the operator and which is in certain respects an improvement over that disclosed in our said application.

A still further objectis to provide a slightly diiferent method of making the splices from that disclosed and claimed in our said application which is equally effective and in some cases perhaps more so than it in producing a satisfactory splice.

With these and other objects in view which will become apparent from the ensuing description-and claims, the following sets forth the details of construction and combination of parts of a specific embodiment of the splicing tool of our invention, which we illustrate as an example, and which will best be understood when read in conjunction with the accompanying drawings in which:

Fig. l'is an exploded fragmentary side elevation of the tool with one of the body plates removed to facilitate illustration of internal construction, the parts being shown in position for receiving a connecting sleeve in making a compression splice;

Fig. 2 is a fragmentary side elevation of the tool with the said plate in place but largely broken away to illustrate the positions of internal parts after the connector sleeve is clamped in the tool following the initiation of a splicing operation, the elements of a typical splice being shown in transverse section;

Fig. 3 is a view corresponding to Fig. 2 but showing the tool parts and splice at the conclusion of the forward compression stroke of the tool;

Fig. 4 is a fragmentary side elevation of the tool on a much larger scale than the preceding figures and illustrating an intermediate stage of the forward compression stroke in the making of a splice;

Fig. 5 on a. like scale is a fragmentary front elevation particularly showing the compression elements of the tool but with the splice omitted;

Fig. 6 is an enlarged side elevation of the toothed anvil die of the tool removed from its seat therein;

Fig. 7 is a fragmentary greatly enlarged top plan view of the aforementioned typical splice connecting together three conductors;

Fig. 8 is a sectional view on line 8-8 in Fig. 7.

Fig. 9 is a greatly enlarged fragmentary side elevation of an indenting rolling die suitable for use in the tool showing the preferred profile of serrations which may be formed in its peripheral surface;

Fig. 10 is a fragmentary transverse sectional view of a modified rolling die, and

Fig. 11 is a fragmentary end view of a correspondingly modified anvil die.

Referring first to Figs. 1-4 of the drawings, that embodiment of the splicing tool of this invention shown therein comprises an elongated body B tapered rearwardly to make a convenient handle and formed of two substantially similar spaced plates 1, 1' held in assembled relation as hereinafter described, plate 1' being shown in Fig. 1 as fully removed from the other parts of the tool to facilitate description of certain of the mechanism which is normally covered thereby, said plate in Figs. 2 and 3, however, being shown in assembled position but largely broken away for the same purpose.

Extending at one end between the body plates is a gripping lever 2 movable on a pivot 3 and having an articulated connection with a gripping jaw 4 which is capable of limited oscillation about a pivot 5, the parts being so arranged that when the lever is closed on the body the free end of the jaw will be moved upwardly with the tool considered in the position shown and when the lever is moved in the opposite direction the free end of the jaw will be correspondingly moved. The lever 2 carries a pivoted latch 6 of a shape to freely pass between the body plates and having a notch engageable with a detent 7 extending transversely of them, a spring 8 biasing the latch toward the detent whereby the gripping lever is automatically locked with relation to the Patented Dec. 11, 1956 body when fully closed thereon; a stop 8 on lever 2 is arranged to limit the spring-biased movement of latch 6 to assure suitable engagement with detent 7 during movement of the gripping lever toward the body.

The tool also comprises an operating lever 9 having an offset forked extension 10 at its inner end, the lever being movable about a pivot 11 passing through the extension. This lever is operable to reciprocate a toothed rolling die 15 located in the forward end of a fork 16 on an axle 17 extending through the sides of the fork, which toward its rear end projects into the forked oifset of the operating lever and is pivoted thereto by a pivot 13.

To afford ways for sliding engagement by fork 16 as it is moved under the influence of the operating lever, a grooved head block 20 is disposed between the body plates at their forward ends as most clearly shown in Figs. 4 and 5, these ways, designated as 21, 22 being respectively downwardly oifset adjacent their outer edges so as to slightly overlap the fork and insure its movement in a rectilinear path.

To maintain the fork in yielding engagement with the ways any appropriate means are preferably provided such, for example, as a spring pressed plunger 25 in a recess in the extension 10 of the operating lever having a head engaging a rearwardly projecting offset on fork 16 (Fig. 4) so disposed that the spring pressed plunger will constantly urge it in a direction to yieldingly press the opposite end of the fork against the ways and hence prevent it from falling toward the anvil die, hereinafter described, with consequent obstruction of the jaw of the tool when the splicing sleeve is being inserted.

It will thus be apparent that the operating lever when moved from the position of Figs. 1 and 2 to that of Fig. 3 will, through the medium of its associated parts, project the fork l6 forwardly along its ways and will in a corresponding manner retract the fork therealong when it is returned to the position of Fig. 1. Desirably latch 6 is made of such length that when the gripping lever 2 is closed the latch will project through body B to form a stop for the operating lever as shown in Fig. 3 to arrest movement of the latter at a point sufficiently distant from the body to prevent a careless operatives fingers from being caught between the parts.

The aforementioned anvil die 30, shown in Fig. 6 removed from the tool, is preferably of rectilinear cross section and is seated in an appropriate groove in gripping jaw 4 and suitably secured therein by welding or otherwise so it will in effect form an integral part of the jaw. For convenience of manufacture the anvil may be provided with a threaded hole in its lower face for reception of a shouldered screw 31 in a bore in the jaw so that after the anvil is placed in its groove and the screw tightened the anvil will be held in fixed position while it is being welded or otherwise permanently secured to the jaw after which the screw may be removed or preferably left as an additional safeguard against movement of the anvil relatively to the jaw.

The anvil die is provided on its upper surface with a series of teeth 32 each conforming in profile to a right triangle of which the hypotenuse forms one tooth face similarly to a standard buttress type screw thread, the teeth pointing inward toward the throat of the tool when the die is seated in the jaw.

The rolling die 15 is likewise provided with teeth 35 on its periphery the faces of which are disposed at suitable angles to the corresponding radii, and also with reduced end portions forming a hub which fits snugly between the jaws of fork 16, the latter being curved or relieved upwardly behind the rolling die axle 17, as at 36, to provide a clearance for a purpose hereinafter mentioned. The respective faces of each of the teeth 35 may be inclined at approximately equal angles to the radial plane of their intersection, but we prefer to have the angles between these faces and said plane substantially more acute in the case of the leading face (as the die is advanced for wardly) than in the case of the trailing face. In other words, as illustrated in Fig. 9 the die being arranged to rotate counterclockwise in the direction of the arrow in said figure, the angle a between the trailing face of a die tooth and the radial plane r of its point is greater than the angle b between its leading face and said plane. The teeth 35 are thus able more effectively to indent the splicing sleeves. Also the points of the teeth 35 are preferably ground down or otherwise flattened to make them less susceptible to wear and to prevent tearing the metal of the sleeve while the indentation is in process.

Both dies are made of tool steel or other suitable material appropriately hardened and ground to render the parts substantially immune to wear and so insure long operative life; with a like end in view the head block 20 and fork 16 are of metal having maximum wear resistance.

To hold the rear portions of plate 1, 1' in properly spaced relation a spacer 37, preferably of plastic or other suitable light Weight material, is disposed between them and held in place by rivets 38 passing through the plates and the spacer, while other rivets 39 are employed to hold the head block in position, all these rivets as well as the several pivot pins and detent 7 being headed over against the outer faces of the plates during assembly of the tool; if desired, the pivots and detent may be appropriately shouldered.

This tool, as noted, is designed for use in indenting or compressing metallic sleeves containing electrical conductors to compact all together in intimate compressive contact whereby electrical resistance at the splice is reduced to a minimum and mechanical strength of the conductors retained substantially unimpaired; Figs. 7 and 8 illustrate on an enlarged scale a typical splice formed by the tool, more specifically, 9. splice between two parallel conductors 40, 41 and a third conductor 42 which are spliced together through the medium of a sleeve 43 in which spaced rows of indentations 44, 45 have been formed by the tool.

In the making of such splice the conductors, initially circular in cross section and usually of copper or aluminum, are first entered in the unindented sleeve, preferably with the end of each extending at least a little beyond that end of the sleeve opposite the one through which it is inserted. The sleeves are preferably proportioned to afford an initial slip fit for the conductors they are designed to receive and when made for splicing wires of sizes such as, for example, #8, #10 or #12 A. W. G. consist of oval or partially flattened tubes ranging from approximately long to approximately 1 /2" long into which wires of these sizes can readily be inserted, the peripheral length of the sleeve cross section substantially determining the number of wires of given gauge which may be spliced with a given sleeve. After the conductors have been properly inserted in an appropriate sleeve in side-by-side relation they then may be utilized to hold the sleeve suspended in space while the splicing tool is being brought to bear.

The tool, with the gripping lever 2 unlatched and at extreme outer position with respect to body B and with the operating lever extended (Fig. 1) is then positioned substantially normal to the axis of the sleeve and the latter entered between the rolling die and the anvil die as far into the throat of the tool as it can conveniently be received. The gripping lever is then closed toward the body until latch 6 is engaged with its detent 7 thereby moving gripping jaw 4 and anvil die 30 toward rolling die 15 and in cooperation therewith into gripping relation with the sleeve and its contained conductors (Fig. 2).

The operating lever is now closed toward the body to thereby pass the rolling die over the sleeve at the point selected, usually approximately A" inside one of its ends, until the said lever reaches fully closed position (Fig. 3), at which it engages latch 6 as a stop, and is then returned to extended position. This operation passes the rolling die twice across the sleeve, indenting its upper surface in spaced serrations through the action of the teeth of the rolling die and its lower surface through being forced against the teeth of the anvil die under heavy pressure which, however, by reason of the novel construction of the tool, is exerted with comparatively little effort on the part of the operator. The circular form of the roller die isprobably responsible for a certain amount of localized I curling of the sleeve during this operation (see Fig. 4 in which such curling is considerably exaggerated) but the relieved neck 36 of rolling die fork 16 affords space for the sleeve to curl in this manner without interfering with the movement of the fork while the peculiarly formed teeth 32 on the anvil die as above described strongly resist any tendency of the roller die to push the sleeve out of the throat of the tool during the indenting operation and so maintain it substantially immobile lengthwise of the anvil.

It will of course be appreciated that after the roller die has been retracted the gripping lever is released by tripping latch 6 and the tool may then be withdrawn from the splice, or moved lengthwise of the sleeve toward its other end and used again in the same manner to indent the sleeve a second time at another selected plate (Fig. 7). As shown in Fig. 8 in the plane of a series of indentations the originally round conductors 40, 41, 42 are normally greatly deformed and voids within the sleeve eliminated, whereby maximum intimacy of contact between adjacent conductors and between each conductor and the sleeve is effected to provide a low resistance path for flow of electrical energy between the conductors through the splice. Usually the intimacy of contact between adjacent conductors is so great that the sleeve itself may actually carry very little of the current in the circuit but we prefer when convenient to utilize sleeves made of the same metal as the conductors and to provide thereon a coating of corrosion-resistant and high conductivity metal such as silver; as a result it is normally immaterial whether the current flows from one conductor to another directly or through the sleeve or partly the one and partly the other.

In splicing aluminum conductors with aluminum plicing sleeves, it has been found that deep indentations workharden this metal to a stressed condition of brittleness which renders it more susceptible to tensile or bending fracture than in the unstressed state. It has been found that this defect can be overcome by providing stepped indenting surfaces on the upper and lower indenters to provide secondary indentations of the type disclosed in United States Patent 2,467,913 to Thomas A. Sanders. Fig. 10 shows a transverse section of a rolling die 15' similar to die 15, having a cylindrical primary indenting peripheral surface 50 identical with the serrated periphery of die 15 and having on each side secondary stepped cylindrical indenting surfaces 51, 52 of smaller diameter. The latter may be smooth or serrated similarly to the primary indenting surface. The anvil die 30, similar to anvil die 30, is provided with stepped secondary indenting surfaces 51', 52' for cooperation with die 15 when it is used. Although the primary and secondary indenting surfaces of die 15' are illustrated as being rectilinearly stepped, it should be understood that the sharp corners of these surfaces may be suitably rounded or otherwise shaped to produce primary and secondary indentations without overstressing r unduly work-hardening the sleeves or encircled conductors.

Although the splices hereinbefore considered have been described and illustrated as connecting together solid conductors, it should be understood that our splicing tool is equally capable of connecting together stranded conductors and connecting stranded with solid conductors, and the terms conductors or wires, as used herein, are accordingly not to be deemed in any sense restricted to stranded and/ or solid conductors or wires.

Although the invention has been described in considill erable detail, such description-is intended as illustrative rather than. limiting, as other embodiments as well as ob vious modifications in construction and arrangement will be evidentto those skilled in the art and may be made if desiredwithout departing from the spirit or scope of our invention as definedin the appended claims.

. Having thus described our invention, we claim and desire to protect by Letters Patent of the United States;

, 1. A tool for splicing electrical conductors or the like disposed in parallel lapped relation within an enclosing ductile metal sleeve of generally oblong transverse shape by impressing a transverse'indentation in said sleeve and conductors comprising a reciprocable roller, a lever connected with theroller for reciprocating it, a body supportingthe lever, a jaw associated with the body for movement toward and away'from the path of the roller, an anvil on the jaw proximate said path, and a second lever carried by the body and cooperative with the jaw to move the latter toward and away from said path, the transverse space on both sides of said anvil being unobstructed.

2. A tool for splicing electrical conductors or the like disposed in parallel lapped relation within an enclosing ductile metal sleeve of generally oblong transverse shape by impressing a transverse indentation in said sleeve and conductors comprising an elongated plate forming a supporting member, a gripping jaw pivoted for oscillation near an end of the plate, a gripping lever pivoted to the plate and having articulated connection with the jaw to oscillate it in correspondence to movements of the lever, an anvil on the jaw, an operating lever having a portion pivoted to the plate near its inner end, a fork pivoted to said portion at the inner end thereof, a roller carried by the fork in alignment with the anvil, and means extending generally parallel to the anvil when the jaw is at the limit of its oscillation toward the roller forming ways for sliding engagement by the fork when reciprocated by actuation of the operating lever.

3. A tool for compressing sleeves on wires comprising spaced elongated plates forming a body, a gripping jaw extending between the plates and pivoted for oscillation near an end of the body, a gripping lever projecting outwardly from between the plates, pivoted thereto and having articulated connection with the jaw to oscillate it in correspondence to movements of the lever, a toothed anvil carried by the jaw, an operating lever having a portion extending between the plates and pivoted thereto near its inner end, a fork pivoted to said portion at the inner end thereof, a toothed roller carried by the fork in spaced relation to and in alignment with the anvil, means extending generally parallel to the anvil when the jaw is at the limit of its oscillation toward the roller forming ways for sliding engagement by the fork, and means operative to yieldingly press the fork against the ways to maintain the roller out of engagement with the anvil in any position of the latter.

4. The method of splicing electrical conductors or the like which comprises disposing the conductors in parallel lapped relation within an enclosing ductile metal sleeve of generally oblong transverse shape, placing the sleeve and contained conductors on a relatively fixed substantially rectilinear supporting surface and while they are so supported applying rolling pressure progressively to the sleeve in a direction substantially normal to the axis of the sleeve at a distance from the supporting surface shorter than the minor transverse axis of the peripheral surface of the sleeve to thereby progressively indent the sleeve and conductors transversely of their respective principal axes.

5. The method of splicing electrical conductors or the like which comprises disposing the conductors in parallel lapped relation within an enclosing ductile metal sleeve of generally oblong transverse shape, placing the sleeve and contained conductors on a relatively fixed substantially rectilinear supporting surface and while they are so supported applying rolling pressure to the sleeve progressively across a zone of less width than the length of the sleeve in a direction substantially normal to the axis of the latter and at a distance from the supporting surface shorter than the minor transverse axisof the peripheral surface of the sleeve while restraining the sleeve from movement along the supporting surface in the direction of the progressive application of the pressure there over to thereby progressively indent the sleeve and conductors transversely of their respective principal axes.

6. A method according to claim 5 characterized in that theprogressive pressure is applied in a plurality of zones adjacent longitudinally of the sleeve to form indentations non-uniform in depth in at least one of said zones simultaneously with the application of pressure to another zone.

References Cited in the file of this patent UNITED STATES PATENTS Stoufier May 8, 1877 Sorensen Oct. 18, 1904 Nedrow Dec. 26, 1905 Gibbons Oct. 12, 1920 Flora Aug. 2, 1921 Davis Mar. 17, 1931 Russell Nov. 10, 1931 Joseph et a1. Dec. 10, 1940 Meyer Apr. 25, 1950 Brock Oct. 21, 1952 Dupre Nov. 4, 1952 Anderson et 'al Feb. '10, 1953

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