US1854783A - Stranded wire connecter - Google Patents

Description

April 19, 1932. W. E. COOK 1,854 783 STRANDED WIRE CONNECTER Filed May 16, 1929 INVENTOR ATTORNEY.

Patented 19, 1932 UNITED STATES PATE i" OFFICE winner a. coox, or s'r. enonen. m Yonx, nssrenoa 'ro omen. can: con- PORATION, NEW YORK, N. Y., A C.ORPOBATION OF NEW JERSEY STRANDED WIRE CONNECTED Application filed ma 16,

My invention relates to stranded wire conii i) this kind for use with electrical conductors,

and particularly stranded wires.

Connecters of the type to which my invention relates are designed for use with conductor wires, the size of which is such as to preclude the bending of the wire when connecting difierent lengths ofsame. Great ditficulty has always been experienced by linemen when splicing such heavy wiresaand the operation has always required a considerable length of time and interferred with the work a of a gang of linemen while such splices were being made. In addition to the loss of time, there was always a possibility, by reason oi the conditions under which such work is done, of the presence of mechanical weakness in the splice, and a condition increasing electrical resistance of the conductor at the splice.

The splicing of adjacent lengths of strand. ed wires has always been a source of great trouble, since it required the untwisting oil the difl'erent strands of the cable, the cleaning of each strand and the formation or a splice as to each strand.

So far as I know, no devices for mechanically and electrically connecting lengths oi heavy stranded conductor cables, which could be quickly connected to the cables by hand, have heretofore been used.

With the above conditions in mind, l have provided a connecter which is so constructed as to permit the hand insertion of the ends of different lengths of stranded cables therein, and firmly grip and compress the various strands of the cable in a manner to prevent the removal of the cable from the connecter while forming a proper electrical connection between the cable and the splicer.

The connecter of my invention embodies a plurality of sets of closing jaws mounted within a casing or shell. having an open end adjacent each set of said jaws, said shell and said jaws having (o-operating wedge surfaces toward the open end of the shell through which the cable is inserted, so that stresses longitudinally of the cable will tend to in crease the gripping action of the jaws upon the cable. The jaws and the shell therefor,

1929. Serial No. 383,607.

in addition to possessing sufiicient inherent strength to resist distortion as a result of stresses thereon by the cable, are so constructed as to possess electrical conductivity equal to, or greater than, that of the cable, which result is secured by proper dimensions of, and material in, the shell, and the necessary intimate connection between the jaws and the shell and between the jaws and the cable.

Certain tolerance is always allowed in the diameter of conductor wires and cables, so that in constructing a connector having sliding jaws of the (character above referred to, provision must be made to secure a substantially uniform contact area between the jaws and the shell, irrespective of allowable variations in the diameters of diflerent wires on cables.

Tests have shown that with a conn'ecter embodying my invention, strains upon the wire sufficient to break same may be developed without any impairment of the joint made by the connecter. Such tests with stranded cables have shown that all of the strands, including the center strand, will break. Such breaking of the wire or cable, however, has always occurred closely adjacent the point of contact between the end Elli of the jaws and the wire or cable, possibly due to the bite of the jaws upon the wire or cable at this point, although during tests it has been shown that such breaking or" the wire or cable does not occur under stresses below the normal breaking point of such wires or cables.

l have found it preferable, however, to so construct the jaws as to secure a graduated gripping action progressively increasing inwardly or the end opening of the shell. In this manner ll secure the desired surface contact between the wire or cable, the jaws and the shell, but avoid possible weakening of' the wire as a result of the cutting action of the jaws necessary to secure a firm grip upon the wire or cable and an adequate surface area contact.

in a connecter embodying therein sliding wedge-shaped jaws, it is obvious that with the movement of the jaws along the co-operating wedge-shaped walls ofthe shell when the jaws open to receive a wire or cable there other, and that when such connecters are used ,with stranded wires or cables, the outer strands will almost invariably spread and enter the space between the jaws, thus preventing a proper closing thereof upon the cable.

To avoid this condition, I provide a on ped closure shield engaged by the jaws and a apted to receive and confine the loose ends of the strands of a stranded wire or cable, so that during the movement of the wire or cable inwardly of the shell with the jaws, the latter may have the desired opening movement to permit the passage of t e wire or cable and the shield and thus ensure the pro er closing action of the jaws directly upon t e cable.

This shield will also serve when the connecter is not in use to exclude dirt from within the shell and the jaws and in large measure prevent oxidation of the gripping teeth of the jaws, which mi ht result 1n the development of resistance in the connecter.

I also provide, in a connecter embodying the invention, means automatically closing the jaws upon the wire or cable upon the completion of the movement thereof when inserting same within the connecter, and means limiting the extent of penetration of the end of a wire or cable within the shell.

The invention consists primarily in a stranded wire connecter em odying therein a shell, open at both ends and mteriorly tapered in opposite directions toward its open ends, a set of exteriorl tapered gripping jaws adjacent each cm of said shell, springs actin to normally thrust said Jaws toward the a 'acent open end of the shell, and cupped shields substantially closing the openings in said shell and engageable b the jaws; and in such other novel features 0 construction and combination of parts, as are hereinafter set forth and described, and more particularly pointed out in the claims hereto apfiended. eferring to the drawings,

Fig. 1 is a longitudinal section through a connecter embodying the invention, .the cupped shield at one end of the shell being shown in a position exteriorly of the shell to permit a showing of the formation of the outer portion of the jaw;

Fig. 2 is a similar view with the ends of adjacent lengths of cable in position in the connecter;

Fig. 3 is a fragmentary portion of one end of the connecter in section, upon an enlarged scale, preparatory to the insertion of a wire end therein;

Fig. 4 is a similar view with the end of the wire in position within the connecter;

Fig. 5 is a transverse section showing the conditions with a stranded wire of exact diameter;

Fig. 6 is a similar view with a slightly oversized wire;

Fig. 7 is a View similar to 5 and 6 with a slightly undersized wire; and

i 8 is a view of one of the gripping jaws.

Li e letters refer to like parts throughout the several views.

In the embodiment of the invention shown in the drawings, the connecter is composed of a shell madein two parts a and b having a screw threaded connection as shown at 0 to facilitate the assembly of the connecter. Held i in position lav the screw threaded connection 0 is a stop iaphra m d, forming a sprin seat in a manner to e hereinafter describe and limiting the extent of penetration of the wire within the shell, as shown more particularly in Figs. 2 and 4.

The shell ab has an opening at each end thereof at a and b respectively, and the opposite ends of this shell are reversely tapered at a and 6 toward the o enings a and b respectively. The tapere portions of the shell are substantially cylindrical invcross section, as shown in Figs. 5 to 7. The exterior of the shell may take any desired form, that illustrated being merely for the purpose of conserving material in the production of the shell and permitting the connecter to be drawn free y over crossarms of the poles carrying the wires.

The shell (1-6 is made of highly electroconductive material, and is of a thickness to not only provide a cross sectiohal area equal to, or greater than, that of any wire with which the connecter may be used, but to afford sufficient strength therein to resist expansion thereof adjacent the openings a and b as a result of the heavy stresses to which connecters of this type are subjected, which may amount to three or four tons, or even more with exceptionally heavy wires or ca- Slidably mounted within, and adjacent each end of, the shell a,b is a set of gripping jaws, each consisting of the segment of,

a truncated cone having a cylindrical ipping face provided with suitable teet or gripping areas capable of penetrating the copper conductor wires with which the connector is used, to only a limited extent how ever.

In the accompanying drawings, each set of such jaws is shown as consistin of three segments 6, f and g which, when 0 osed together as stated, form a truncated cone, the outer wedge-like surface c-fg' of which are adapted to slide along and engage the interior wedge-like surface a or b of the shell. It is obvious that with the movement of these jaws, the gradually increasing diameter of the opening within the shell will permit them to separate so as to increase the diameter of the opening within the jaws to permit the passage of a wire, the diameter of which is III relatively greater than the diameter of the toothed opening within the set of aws. The teeth of the aw elements a, f and g are shown at h.

Acting between the disk d and the inner ends of each set of jaws is an expansion spring 2'.

Since the jaw construction at one side of the disk 01 is identical with that at the other side, the same reference letters are used in connection with the jaws and with the spring at one side of said disk, as are used with the corresponding parts on the other side thereof.

The detailed construction of the jaws for securing a progressive increase in their effective gripping action, inwardly of the opening a or b, and for causing them to adapt themselves to wires of var ing diameters, will be more fully described hereinafter.

It is obvious that with the movement of the jaws of one set inwardly of the shell, they will. move circumferentially away from each other as the wire is inserted between the jaws. This spacing of the jaws, when they are opened, is shown at w in Figs. 1, 3, 5 and 6 of the drawings,-and will vary with difierent degrees of movement of the jaws inwardly oi the shell.

Since the strands at the end of the wire or cable are unconfined, it is obvious that such ends are free to spring outwardly and enter the spaces :0, thus preventing the subsequent closing of the jaws by a reverse movement thereof, initially by the spring 2', and subsequently by thepull upon the cable or wire.

To correct this condition, ll provide a cupped shield j, preferably made of thin, soft metal such as copper, which may be p'ositioned within the open ends a or b of the shell and be engaged by the jaws adjacent each said open end. The lip j of said shield is flared outwardly so as to substantially engage the shell and preferably is of greater diameter than the mouth of said opening.

This shield has three distinct functions. The first is to confine the separate strands of the wire when it is inserted in the jaw, and prevent the spreading of the strands during the insertion of the wire in the connecter, and subsequently thereto. The second function is to exclude dirt and other foreign matter from the shell when the connector is not in use, and substantially exclude atmospheric air therefrom so as to minimize possibility of oxidation of the teeth 71 The third function is to prevent a lineman from thrusting his finger Within the connecter which would result in the necessity for taking down the connector in order to release the finger without injury thereto.

The material of said shield is such that I when it is forced inwardly between the jaws,

ing strains developed by the spring 11, said spring being a fairly stlfi spring.

To prevent the maximum bite of the aws upon the wire or cable occurring closely adjacent the opening a or b, the outer wedgelike surfaces e, f and g are given a higher pitch than the tapered portion a or b of the shell, the variation however being measured only by a few thousandths of an inch. As a consequence of this construction, the jaws e, f and will initially close upon the wire or cable adjacent the spring 71, there beinga' progressively decreasing penetration of the teeth It toward the o enmg a or 6, although all of the teeth will rmly grip and penetrate the wire or cable.

In Fig. l of the drawings, to the right I have shown this condition greatly exaggerated, the shield j being shown separated from the shell at this side for the purpose of illustrating this condition.

There is a further condition, due to the tolerance allowed in conductor wires or cables, which has to do with matter of the conductivity of the connecter. The tapered portions of and 72 of the shell have the same pitch throughout, nd it is obvious will vary in diameter at every point thereof. The segmental gripper jaws c, t and 9', when brought togetherbeing in substantially the form of a truncated cone, can conform to and bear against the tapered portions (2 or 72 only in one position the jaws. llf these jaws, when they close upon the wire, are inwardly of the shell as to this position, it is obvious that where they engage the tapered portion, the opposite edges of each segment will be spaced away -from the shell, and ii, when they grip the wire or cable, they be away from this position toward the opening a or 7), it is obvious that the point of engagement of the jaws with the shell will be only along adjacent edges of the segment.

Expressed another way, as the jaws separate they their true conical term, and. the radius of he arc of the wedged outer surface thereof will be of a radius relatively shorter than 51 e radius of the tapered portion,

or the shell. Consequently, the arc of each segment bears the relation to the tapered portions, of a small circle within larger circle.

The same condition will be present if the jaws are beyond their normal engaging point toward the opening a" or 5 except that then the engaging portion of the jaws will be of a longer radius than the adjacent portion of the tapered opening within the shell. Under either condition the result is a reduction in that contact area between the jaws and the shell necessary to the degree of conductivity required to avoid the development of resistance in the connecter.

To correct the above conditions, ll provide each jaw segment e, f and g with one or more longitudinally extending weakened portions lllll tween the two sections will be k throughout the length of each jaw segment. These portions 7: are in the form of slots extending well into the body of the jaws, and their presence will cause the deformation of a segment as a result of the pull thereon in stretching a wire, or while the wire is in position so as to cause substantially every portion thereof to conform in radius to the portion of the interior taper of the shell with which it contacts. This will cause the jaws to automatically adapt themselves to wires ofdifi'erent diameters, as to the gripping jaws, and to adapt themselves to the portion of the shell with which they engage, so as to secure the maximum electrical contact at all times, irrespective of variance in the diameter of different wires or cables.

The operation of the herein described connecter is substantially as follows The herein described connecter is for use with electrical conductor wires or cables, and is ada ted to be rmanently incorporated in a ine of sucli wires or cables being stretched by the linemen.

' The parts a and b of the shell are made separate and connected in the manner described merely to facilitate the assembly of the connecter, and preferably the joint bermanently connected by soldering before to connecter oes into use. This is to prevent any possible reakageof the line, due to the loosening of the screw threaded joint 0 as a result of movement of the line from vibration due to wind or other conditions.

The stop disk d is held in position by the abutting edges of the two portions (1 and b of the shell, and the springs i are tensioned as a result of the connection of the two shell portions so as to have a normal tendency to thrust the jaws (2, and g towardthe open ends a'-b' of the shell. These springs are of a diameter relatively greater than the toothed openingof the jaws, so as to permit the free passage of the wire or cable through the springs until the end thereof is in abutting relation with the stop disk d, (see Fig.

Before the jaws, the springs and the disk are properly assembled within the shell, cupped shields j are placed within the open ends a'b' of the shell, thus holding the jaws inwardly of the shcll,thetension of the spring 2' causing the opening within the jaws to be enlarged to an extent to receive and engage said shield. The exterior diameter of said shield is relatively greater than that of the wire or cable with which the connecter is to be used. The shield is positioned within the shell with the lip j thereof projecting over the ends of the jaws into substantial contact, circumferentially of the lip, with the shell. As heretofore stated, the positioning of this shield within the opening, and its retention therein by the jaws will close the openings a and b and protect the jaws while the connecter is not in use.

When it is desired to make a splice, it is merely necessaryfor the linemen to take the end of the stranded wire or cable and locate it within the cup (1 shield j, the flared lip of which will gul e all of the outer strands to within the cup. This can be instantly done, and by a contlnuin pressure the cup and the confined end of tl e wire or cable may be forced inwardly of the, shell. The sides of the shield effectively prevent any of the outer strands of the wire or cable springing outwardly in the ga between the aw segments e, f and g. Furt ermore, the shield ensures a simultaneous, similar opening movement of each of the jaws which might not be the case if she wire or cable had an irregularly cut en Springs i will be further tensioned as a result of the movement of the jaws of a set inwardly of the shell, but immediately upon the shield passing the inner ends of the jaws, said springs will act to close the jaws upon the wire or cable adjacent the portion thereof confined by the shield.-

The mounting of the end of the wire in the connecter requires merely a second or two, and the shield, still upon the wire, will contact with the stop disk d substantially simultaneously with the closing of the jaws upon the wire or cable.

When the wire is once positioned and the jaws closed upon same, a pull upon the wire incidental to the stretching of the wire between poles, or the subsequent sag of the Wire, will merely increase the effective gri of the jaws upon the wire until the teeth thereof have penetrated the wires to the maximum extent. These teeth may be ordinary 1U screw threads, or may be ratchet teeth, as desired, the teeth being very short and numerous to prevent excessive cutting of the wire while ensuring a contact area equal to, or greater than would be secured by a plain 110 aw.

Owing to the necessity of the avoidance of likelihood of loose ends of wire, due to the failure of a connecter, gripping teeth upon the jaws are essential.

If the wire or cable be of standard diameter, the jaws will ultimately position themselves so that the outer surface thereof will be throughout its extent, substantially coincident with the surface of the tapered por- 1U tions aand b. The variance in the pitch of the wedge-shaped exterior surfaces of the jaw segments, as compared with that of the tapered portions a -b will have the effect of merely limiting the extent of penetration I l of the teeth It at the end of the jaw adjacent the open end a or b of the shell. As stated, this variance is merely a few thousandths of an inch, and is compensated for by the increased penetration'of the teeth towards the inner ends of the jaws, so as to secure electrical contact between each jaw and the shell for the full length and width of the jaw. This condition ensures the strongest bite of 8 the jaws well within the shell, and a ro- 10 portion of the wire, where the maximum penetration of the teeth It occurs. I

With a wire of standard diameter, and by standard is meant the exact diameter called for without taking advantage of the tolerance allowed, the jaws will be positioned in the shell where every portion of the exterior thereof will be forced into intimate contact with the shell. If a wire or cable, however, be of a diameter above standard and yet within the tolerance allowed, a solid segmental jawwould contact with the shell only along the high point of the arc of the outer surface of the jaw were it not for the weakened portions is which will permit the expansion of the jaw at both sides of the point of contact, as a result of the closing of the weakened portions k, as shown in Fig. (i, or of the breakage ot' the jaw adjacent the bottom of said weakened portion. Either condition will suifice to change the diameter both exteriorly and interiorly of the jaw so as to permit it to conform to the shell, and also to the wire or cable.

If the wire or cable be undersized and yet within the tolerance allowed, the jaw, it solid, would engage the shell only adjacent opposite edges of the segment The weakened portions la, however, will permit the collapsing of the jaw intermediate the sides of the segment, thus reducing its diameter as a whole, both exteriorly and interiorly of the jaw, with the same result in securing electrical contact between the shell and the jaw,

and the jaw and the wire, as heretofore referred to in connection with Fig. This condition is shown in Fig. if. The condition with the standard size of wire is shown ft will be noted, by reference to Figs. 2 and l, that the shield 5' remains upon the end of the wire or cable, but has no further function after passing from the range of the jaws e-f-g, beyond preventing the spreading of the strands of the wire.

The action of the jaws e, f and g, in addition to grippin the wire in the manner described, is to rmly compact the diilerent strands and thus ensurethe desired electrical contact between these strands. The extentof this compaction is so great that in a testing machine, the center strand itself,

which receives no. mechanical support iirom any of the other strands, was held so firmly as to break at substantially the same time as the other strands.

A connecter embodying the invention has been thoroughly tested by approved laboratones, not only as to its efiicacy in forming an electrical joint between different lengths of wires or cables, but as to its holding capaclty in making the connection. S uch tests have shown that the electrical resistance at the connecter is substantially the same as 1n a section of thewire tested of substant ally the length of the connecter, and in fact, it was found that the connecter did not develop as much heat as did the wire itself. As to the strength of the mechanical connection between the connecter and the wire, the wire itselt' invariably broke without any yielding of the connection between same and the connecter. The stresses to WlllOh such wires were subjected, at'all times exceeded the requirement for tensile strength in the wire or cable.

lhe connecter of my invention may be used w th bare wires or cables, or with insulated w res or cables, it being necessary of course with the latter to strip the insulation therefrom before making the connection.

To ensure clean metal at the connection, between the jaws and the wire or cable, the lineman may turn the connecter upon the wire which will serve to eiiectivelyiemove from the teeth or from the wire or cable, any oxide or other foreign substance. L

As heretofore stated, the exterior form of the connecter is merely to -facilitate the drawing of the wire or cable over cross arms when the linemen are stretching same.

is ,not my intention tolimit the invent1on to the precise details of construction shown in the drawings, it being apparent that such may be varied without departing from the spirit and scope of the invention.

Having described the invention, what I claim as new and desire to have protected by Letters Patent, is

ll. stranded wire connecter embodying therein a shell, open at both ends and interiorly tapered in opposite directions toward its open ends, a set of exteriorly. tapered gripping aws ad acent each end of said shell,

means acting to normally thrust-said jaws toward the adjacent open end of the shell, and cupped shields substantially closing the openings in said shell and engageable by the aws.

2. A. stranded wire connecter embodying therein a shell, open at both ends and in teriorly tapered in opposite directions toward its open ends, a set of exteriorly tapered gripping jaws adjacent each end of said shell, rneans acting to normally thrust said jaws toward the adjacent open end of the shell, and cupped shields each having an outwardly flared lip, the bottom of said shields closing the space within said jaws and said outwardly flared lips substantially closing ad acent open end of the shell, and cupped the o enings in said shell and the sides of said s ields being engageable by the jaws.

3. A stranded wire connecter embod ing therein a. shell, 0 en at both ends an interiorly tapered in opposite directions toward its open ends, a set of exteriorly tapered gri ping jaws adjacent each end of said she I, the taper of said jaws being of a relatively higher pitch than the taper within said shell, means acting to normally thrust said 'aws toward the adjacent 0 on end of the s ell and cupped shields su stantially closin the openings in said shell and engagea 1e by the jaws. 4

4. A stranded wire connecter embodying therein a shell, open at both ends and interior' ly tapered in op osite directions toward its open ends, a set 0 exteriorly tapered gripping jaws ad'acent each end of said shell, the taper of said aws being of a relatively higher pitch than the taper within said shell, means acting to normally thrust said jaws toward the shields each having an outwardly flared ip, the bottom of said shields closing the space within said 'aws and said outwardly flared lips substantially closing the openin s in said shell and the sides (if said shields eing engageable by the jaws.

5. A stranded wire connecter embodying therein a shell, open at both ends and interiorly tapered in opposite directions toward its open ends, a set of exteriorly tapered circumferentially expansible and contractible gripping jaws ad acent each end of said shell, means acting to, normally thrust said aws toward the adjacent open end of the shell,

and cupped shields substantially closing the openings in said shell and engageable by the g jaws.

6. A stranded wire connecter embodying therein a shell, open at both ends and interiorly tapered in opposite directions toward its open ends, a set of exteriorly tapered segmental lpping jaws adjacent each end of said she I, each of said jaws having a weakopenings in said shell and engageable by the aws.

8. A stranded wire connecter embodying therein a shell open at both ends and interior- 'ly tapered in opposite directions toward its said jaws toward the ad acent 0 en end of L P said shell, and cupped s ields each havin an outwardly flared lip, the bottom of sai shields closing the space within said jaws and said outward y flared lips substantiall closing the openings in said shell and he sides of the shell bein engageable by the jaws.

9. A stran ed wire connecter embodying therein a shell open at one end and interiorly tapered toward its open end, a set of exteriorly tapered grip ing jaws adjacent the open end of said she 1, means acting to normally thrust said jaws toward the open end of the shell, and a cupped shield substantially closing the opening in said shell and engageable by the jaws.

10. A stranded wire connecter embodying therein a shell open at one end and interiorly tapered toward its open end, a set of exteriorly tapered grip ing jaws adjacent the open end of said she? thrust said jaws toward the open end of the shell, and a on ped shield having an outward- 1y1 flared lip, t e bottom of said shield closin t e space within said jaws, and said outwa ly flared lip substantially closin the opening in said shell, the sides of said 3 ield being en ageable by the jaws.

n witness whereof I have hereunto aflixed my signature this 15th da of May 1929.

. WILL AM E. coon.

1, means acting to normally ened outer portion extending longitudinally thereof, means actin to normally thrust said jaws toward the a jacent open end of the shell, and on ped shields each havin wardly flares lip, the bottom of said shields closing the space within said jaws and said outwardly flared 1i s substantially closing the openings in said s ell and the sides of said s ields eing en ageable by the jaws.

7. A strande wire connecter embodying therein a shell open at both ends and interiorly tapered in oppositedirections toward its 0 n ends, a stop diaphragm within said s ell, a set of exteriorly tapered gripping jaws adjacent each end of said shell, springs acting between said stop diaphragm and the jaws of each set to normally thrust said jaws toward the adjacent open end of'the shell, and cupped shields substantially closing the an out-

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