US3333044A - Passageway structure for liquid coolant at gun and transformer ends of welding cable having novel internal surface bearing for alternate polarity strands - Google Patents

Description

July 25 1967 WILLIAM A. ToTo 3,333,044

PAssAGEwAY STRUCTURE FOR LIQUID cooLANT AT GUN AND TRANSFORMER ENDS oF WELDINGEABLE HAVING NovEIJ INTERNAL SURFACE BEARING FOR ALTERNATE POLARITY sTRANDs Filed April 23, 1965 2 Sheets-Sheet l WELDING III-:AD

j' "TEKESQA A" WILLIAM MOTO Y I v AT TQRY 3,333,044 ANSFORMER July 25, 1967 WILLIAM A. TOTO PASSAGEWAY'STRUCTURE FOR LIQUID COOLANT AT GUN AND TR ENDS OF WELDING CABLE HAVING NOVEL INTERNAL SURFACE BEARING FOR ALTERNATE POLARITY STRANDS Filed April 23, 1965 2 Sheets-Sheet 2 United States Patent O 3,333,044 PASSAGEWAY STRUCTURE FOR LIQUHD COOL- ANT AT GUN AND TRANSFORMER ENDS OF WELDING CABLE HAVING NOVEL INTER- NAL SURFACE BEARTNG FR ALTERNATE POLARITY STRANDS William A. Toto, 3645 Warrensville Center Road, Cleveland, Ohio 44122 Filed Apr. z3, 196s, ser. No. 450,421

' 7 Claims. (Cl. 174-15) ABSTRACT OF THE DISCLOSURE A Connector unit for alternating polarity electrical welding cable having special cable rope construction with 14 groups of strands of elliptical cross section consisting of 4 groups forming a core section and l0 groups forming a peripheral section surrounding the core section to provide minimum wear points in the assembly of groups and having an internal support element.

This invention relates to a cable terminal unit and more particularly to an alternate polarity multiple conductor terminal unit having a greatly extended operating life due to a novel end structure which reduces fatigue chang of the line wires induced by kick and twisting of the wire and which greatly facilitate the problem of dissipating large quantities 'of internally generated heat.

The cable terminal of this invention is specifically intended to be used in connection with the kickless cable of the type described and claimed in U.S. Patent No. 2,320,470 to M. G. Rees and No. 2,308,673 to L. S. Burgett.

According to the invention there is provided for an alternating polarity,rkickless electric water-cooled cable, internal and circumferential bearing surfaces acting together to provide sliding surfaces for the rope conductors at the welding gun end of the cable. These surfaces permit free movement of the ropes and prevent chaiing of the fine wires while maintaining the ropes in spaced apart relation, thus maintaining open the coolant flow passageways when the cable is bent at the welding gun end. A spiraling shaped swaged connector is provided for connecting the ropes of one polarity to the welding gun. The connectors shape approximates the helix of the rope lay,

mating in overlapping relation with an opposite polarity connector containing an aperture for passage of coolant ow.

At each end the cable consists of two leads Wound about a perforated resilient sleeve containing a collapsible hollow core element such as helical spring. The end of the core has a helically shaped semirigid spacer located six to eight inches beyond the terminal at the transformer end lof the cable, enabling the coolant to be conveyed directly to this region, therebyforming a coolant pocket between the spacer and the end of the connector. This arrangement assures that coolant is always accessi-ble to the rope conductors at the hottesty portion of the cable. Coolant flow is distributed over the outer rope conductors of the cable by means of an outer or major connector surface formed with a circumferential manifold groove connecting with two helical ow channels. Y v

There is further provided, in combination according to the present invention, an improved wear-point reducing strand configuration for the negative wire ropes. There is provided a 14-bunch rope construction of tine strandedV wire composed of a core of 4 bunches surrounded by a peripheral layer of 10 bunches. The twist direction of each ICC bunch is opposite to its adjacent bunch in the outer and inner core groups. Each bunch in the core group has an eccentric transverse cross section to establish points of physical contact with bunches of the outer group. The closing helix of both the outer and core groupings is the same and has the same direction to maintain, the direction or the helix angle of the formed negative connector. Thus, wear caused by induced magnetic fields, as well as by physical contact of the bunches, in each rope is reduced.

For an introductory discussion of prior art arrangements relating to welding cable assemblies, reference to applicants U.S. Patent No. 3,127,467 may be made.

The kickless cable referred to in this disclosure has alternating polarity configuration wherein multiple strand cable lead conductors are alternately spaced on a circle about the longitudinal axis and spirally wound about a core, and incorporating inner and outer-non-conductive sheaths adapted to internally separate the conductors of opposite polarity, both leads of which are jacketed by a flexible hose capable of carrying coolant water.

Perhaps the most important practical consideration for efficient cable usage is the problem of removing the heat generated by the cables resistance. The basic heat equation W=12RD Where I Current-amps R=Total resistance D=Duty cycle or on time very neatly illustrates the large quantities of energy dissipated in ohmic heating and must be removed by the coolant flow in order to achieve the maximum potential of thecables MCM size and to prevent the premature deterioration of the cable.

VIt should be-noted here that the I2 term commonly varies between 108 to 4 108 and that the resistance value (R) increases 3.5% with each 10 F. rise in temperature of the copper. This increase in coppers resistance, of course aggravates the problem by completing the viciously ascending heat generating cycle.

This problem is further complicated when the welding gun operator severly bends or twists the welding gun and cable assembly in order to perform his spot welding operations on a moving auto body. These bends will restrict the flow at the kinked cable areas, thereby causing localized heat spots. An alternately wound kickless cable is divided into two concentric groups of ropes by a thin rubber tube. The tube serves -as a separator and insulator for the two cable leads. It has been an undesirable characteristic of this cable to exhibit aV major unbalance division of ow between the central lilow through the inside of the separator when compared to the external flow outside of the separator. The conductors inside the separator will always receive less than half of the flow. This imbalance is caused by the twisting and tightening action of the helix on the cable assembly. The inner group of conductors are forced to hug the solid core. Similarly, the separator becornes tightly woundabout the inner group of conductors, with the net result of closing up the inner or positive ow passageways, while increasing the size of the outer or negative flow passageways. When the assembled cable is subjected to line pressure, the cables outer hose or jacket will expand and further open up the outer negative ow passageways about the outer group of cables, thereby causing Van even greater unbalance ow condition.

This condition, as well as the others previously described, will produce localized cable hot spots along the inner group of rope conductors that will seriously damage the separator and cause the two leads to short out causing the cable to quickly destroy itself.

It now becomes apparent that the major cause of cable failures are either of two types: (l) Separator failure or burn-out caused by hot-spot 6 to 8 inches beyond the terminal at the transformer end of the cable; (2) rnechanical breakage of the fine wires 6 to 8 inches beyond the terminal at the gun Welder end of the cable.

Separator failures are lcommon when the surface temperatures of the strands exceed 250 F. during continuous operations. The separators generally extruded from the Buna-N com-pounds can be expected to rapidly deteriorate and flake away. Their residues can be found as deposits on the coolant stream passageways of the cable and its terminals, and they will further impede the llow and accelerate cable failures. The cable area 6 to 8 inches beyond the terminal lugs at the transformer connection is most detrimentally affected by the high temperatures of the coolant flow, since at this point a balance is reached between the heat dissipated into the transformer lugs and the high point of the longitudinal temperature gradient along the cables length. It is at this point that many cables fail because of the insufficient heat transfer rate due to the large amount of accumulated heat in the coolant llow stream by the time it reaches its area coming up from the gun end of the cable.

The other equally serious problem causing failures in cables is brought about by mechanical fracturing of wires also in the area 6 to 8 inches beyond the terminal at the gun end previously described in applicants U.S. Patent No. 3,127,467. This type of breakdown is caused by the mechanical bending stresses imparted to the wires as the cable is kinked or bent by the operator. When the cable `is sharplyjbent the three inner conductors are unable to realign themselves into compensating positions because of high frictional forces, and thereby restrict the water llo-w at this area which further accelerates the breakage to the fine wires.

It is the object of this invention to provide a highly ellcient heat transfer system immediately beyond the terminals of six rope configuration welding cable, particularly in the area beyond the terminal at the transformer end of the cable.

Another object of this invention is to provide internal and circumferential bearing surfaces for each of the six rope conductors at the area to the rear of the terminals at the gun end of the cable in order to overcome wire fracturing at this point, when the cable is severely kinked.

Another object of this invention is to provide a terminal connector to position the inner and outer conductors so that they are free to align themselves behind the terminals during severe bending of the cable. Other objects -of the invention will in part be obvious for a fuller understanding of the nature and objects of the invention. Reference is made to the following detailed description taken together with the accompanying drawings in which:

FIG. l is a fragmentary diagrammatic View of the flexible liquid cooled cable of the present invention;V

FIG. 2 is a fragmentary isometric view of a preferred embodiment of the flexible cable showing the positive connector lead removed from the terminal assembly;

FIG. 3 is a fragmentary plan view of FIG. 2 `taken substantially on line 3,-3;

FIG. 4 is a vertical sectional view taken substantially on line 4-4 of FIG. 1;

k FIG. 5 is a vertical sectional view taken substantially on line 5-5 of FIG. 2; and

FIGS. 6, 7 and 8 are transverse cross sectional views of the cable assembly of the invention along the cuts 6--6, 7-7 and 8 8 of FIG. 3.

Referring to FIGS. l, 2 and 3, the flexible water-cooled electric welding cable assembly embodying the present invention is generally designated by numeral 10. The cable assembly 10 is shown extending between transformer T and welding gun W. Connecting the cable assembly 10 to the transformer and welding guns are shown two terminals each composed of two conductive elements 11 and 12, positive and negative respectively, insulatingly separated by a conductive block 11a. Bolts 13 passing through a hole in terminals 14 and insulators 15 secure the elements to the terminals. The conductive elements 11 and 12 may be a flexible lamination of copper strips composed of a pair of identical semicylindrical sections, generally machined from round copper stock and sawed into two semicylindrical lengths. The shape of the elements 11 and 12 can be made to suit most any application. A relatively thin ilat insulating element 16 insulates conductive block 11a from element 12 along their joint faces. Theaded holes 18, shown in the negative conductive block 11a, are used for fastening the conductive element 11 to the terminal. Coolant ports 19 and Ztl, located in the block 11a in each terminal assembly, are threaded to receive hose fittings carrying coolant to the cable. The coolant is introduced at the welding gun end which is usually the lowest point in the suspended cable so as to ow upward through the cable and emergin-g from port 20 in the top terminal that is attached to the transformer overhead.

In the preferred embodiment as shown in FIGS. 2 and 3, the rearward end of each terminal conductor 11 and 12 is radially undercut to form axially projected, doubly beveled tangs 21 and 22 that are integral with the body yof the conductive elements, and are each adapted to receive in mating arrangement forming a strong lap joint a cable lead connector whose outer surface 23 is generally conical in form in order to snugly lit within the internal diameter of the cable hose 5. The negative connector 26 and positive connector 24 are bolted to the tangs 21 and 22 using 18-8 stainless steel bolts 2S. This lap joint can further be secured by silver soldering the mating surfaces together.

As best seen in FIGS. 2, 3 and 7, the interior faces of the terminal conductors 11 and 12 may be provided with axial grooves or channels 27 and the insulating sheet 16 is slotted in this area to match the channel opening in order to facilitate the coolant flow through the channel. The channel then becomes the common distribution point for the division of flow for the positive and the negative coolant flow passageways. Coolant ports 19 and 20 located in each negative conductor block 11 are similarly located but are not shown in the positive conductor elements 12.

It will be noted (see (FIG. 7) that when the terminal is assembled, inward facing surfaces 28 of the tangs 21 and 22 are spaced apart to form a space 29 which functions as a coolant portoning port for controlling the negative flow, eg., outer flow, to the negative outer group of 3 ropes. The flow to the negative lead (outer flow) can be varied by tapering the sides of the tangs 21 and 22 in conjunction with varying the crosswise length of the dividing insulator strip 16 at point 30. Accordingly, decreasing the taper and increasing the length will tend to decrease the negative flow (outer flow) over the negative conductors and thus it is possible to meter and to balance the negative and positive flows.

As shown in FIG. 2, it should be noted that the positive connector 24 has been shown disconnected from the positive terminal tang 21. Two bolts `25 pass through the connector clearance holes 31 and are threaded into the tangs. This better illustrates the construction details of each of the connectors. Similarly,rnegative connector 26 can be disconnected from the negative tang 22 by removing the threaded bolts 25. The negative connector 26 ties together as a conductive unit. The terminal end portions of each group of 3 negative core conductors 32 of like polarity are inserted into -a preformed conductive metal sleeve 33 and swagged together in a heavy press using a progressive type die in order to achieve .an intricately contou-red shape. This connector 26 transpositions the 3 ropes and from their outer circumferential positions into a comrnon semicircular cross section. The connectors in this description are twice the length as those set forth in applicants U.S. Patent No. 3,127,467 and contain two helical fluted recesses on a circumferential surface .and are shown as 33a. The fluted recesses 33a act as flow channels to convey coolant iiow passing through the tang flow proportioning port 29 and hence around a manifold ow groove 34 which in turn feeds the two spiraling uted -grooves 33. The coolant flow can now flow evenly distributed along the 3 outer negative strands for eflicient removal of heat generated. The helix angle in the connector is approximately The strands thusly maintain the same helix angle through the connector collar as they have throughout the length of the cable.

The present conductor construction comprises a novel 4-in. core and l() peripheral conductor bunches to form a stable configuration in which elliptically-shaped bunches are present in the core to support the outer bunches. This elliptical core configuration, allowing 6 cross-over points, is new in the welding cable field.

Y In contrast to chang points for the concentric 7 x 9 rope, the 14-bunch herringbone herein reduces wire fracture by providing greater lateral contact surface areas than in the 35 cross-over point of the prior art cable. As Vthe contact areas become greater, the wearing pressures become smaller.

It has been verified by extensive testing (to be described later) that it is important to the life of the cable, particularly in the area behind the terminal, that the strand approaching angle into the connector collar should be the same as the outer helix angle of the strands. All presently marketed kickless cables make no provision for attaching the rope strands to the terminals so that the helix angle is maintained at the entrance to the rear of the terminals. Unless this is done severe bending stresses are imposed on the strands because they are caused to turn a sharp corner upon entering the terminals.

In the present invention the connector section at the manifold groove line makes a smooth transition from the helix angle t-o one that is parallel to the longitudinal axis v of the cable. Since this transition is carried out at a rigid section of the cable, no bending stresses are imparted to the strands. Further, -applicant has designed the connector openings with a generous tapered and flared entry portion 35 to permit additional freedom of wire movement while thecable is being bent.

As stated at the outset, cable conductors attached to terminals at the welding gun end of the cable have a tendency to fail in the immediate area of the cable to terminal connection. This failure is attributed in large measure to the repeated subjection of the cable conductors to severe bending stresses in this area since the cables are acutely bent by the welding gun operator. In order to overcome this diiiiculty, a .G60-inch wall nylon sleeve 36 is fastened over both connectors and extends beyond them for at least 11/2 times the c-ables diameter. The sleeve serves two purposes: (l) It provides a better bearing surface over which the outer 3 strands are able to slide. (The co-eiiicient of frictionl of nylon is considerably less than that of rubber.) (2) TheV nylon sleeve offers just the proper amount of semirigidity to the area so as to increase the radius of curvature of the cable while it is being connector lead 24 disconnected from the rear portion of the positive element 12 of the terminal. An inner resilient sheath 37 (FIG. 8) is used as the insulator enclosing one set of positive conductors strand 38, wound about a central core assembly. The negative conductor strands 32 are helically wound and in alternating positions with the positive strands. Both groups are insulated from each other by the insulating sheath 37. Sheath 37 has been pulled away from the cable .and is shown in FIG. 2 in a relation which illustrates the structural interrelation of the helically grooved or 'uted nylon conductor bearing 39 and the core assembly that is composed of a loosely wound brass spring 40 inserted into an oversized perforated resilient tubing 41. The inner nylon bearing has `a central bore and is approximately .7S-inch long with 6 arms .375 long and located .25 of an inch beyond the end of the circumferential bearing sleeve 36.

The bearing 39 has inner helical flutes 42, is shaped to snugly fit the 3 positive conductor strands and is held in contact with the positive conductors by the spring 40 which passes through its central bore'. The bearing is restricted from moving either down the length of the cable by the perforated resilient tubing 41, and it cannot move towards the positive connector because the conductors 38 are brought together in tight relation as they enter the connector 24. It can now be appreciated that as the cable is severely bent beyond the terminal, the negative or outer group of 3 ropes will slide along the inner surface -of the nylon sleeve 36 and concurrently the inner or positive group of 3 ropes 38 will slide along 4the fluted .grooves 42. The combined action of the nylon collar 36 and the nylon wheel 39 imparts universal bearing action to each of the 6 ropes of the cable. This results in even sliding action overcoming the concentration of bending stresses on the strands by allowing for their mutual movement and realignment throughout the cables bending cycle.

The conductor portion immediately forward of the internal nylon bearing 39 of the positive lead is most adversely affected by high temperatures generated by the heavy current flows, and for efficient operation according to the invention, coolant reaches this portion in plentiful quantities about the congested conductors, particularly when the cable is bent. It can be seen in FIG. 3 that in the vicinity of the loosely wound spring 40 and the bearing 39, there is-created a space providing reservoir pocket for free-flowing coolant that may intimately flush the major portion of the conductors in this area, thereby providing an ideal turbulent flow condition for good heat transfer action. v

The loosely wound spring is inserted into a flow metering port axially located in the connector 24. This port 43 may be drilled after the connector has been formed by swaging. The diameter of the hole is varied to balance out the systems distribution of flow.

The -spring core 40 continues through the internal bearing 39 and acts as a core, jacketed by a perforated resilient tube whose internal diameter is 35% greater than the springs outs-ide diameter. The lother end of the cable, i.e., the transformer end, is identical to that shown in FIG. 3 except the ports in the terminals become out-lets instead of inlet ports.

Further reduction in the wear of the cable is provided by the strand grouping, shown in FIGS. 4, 5 and 6, whereby, as designated in FIG. 4, each rope consists of 14 strand groups arranged in an outer or peripheral :group 51 of 10 strand groups 51a, 51h, 51C, 51d, 51e, 51j, 51g, 51h, 51z` and 51j and an inner or core group 53 of 4 strand groups 53a, 53h, 53C and 53d. The. sense of the twisting of each one of the strand groups is indicated by an arrow, it being noted that each `outer group of strands 51 is twisted oppositely from its adjacent strand group, group 51a being opposite to SIb-51j being opposite to 51a.

The groups 53a-53d of core groups 53 lare also twisted oppositely in the same manner as those of the outer group. The groups of the core 53 are elliptical in cross section so that as a result the wear .points due to induced magnetic fields occur only at the six points 55. This reduces chafing.

The function of the perforated resilient core assembly in the alternate polarity type cable of this disclosure is similar to that given in applicants U.S. Patent No. 3,143,593 for a pulsating iiow core of a diametrically opposite type cable, whereby the kicking or pulsating action of the conductors due to their reactive forces alternately squeeze into land away from the loosely fitting elastic tubing causing a lateral displacement of water from the central core in a ushing eddy current manner. The correct proportions of each of the negative and positive metering ports result in the desired o-ptimum balance of 55% of total flow pass-ing through the passageways among the positive ropes and 45% along the passageways .among the negative outer ropes. As the hose ages, it will expand and the iiow balance will change to a 50-5'0%.

The cable described in this invention and noted as Cable C ha-s been competitively tested lalong with the type of cables described in U.S`. Patent No. 2,504,777 and U.S. Patent No. 2,691,691 called Cable A, and U.S. Patent No. 2,702,311 called Cable B. The results have been summarized and .are tabulated below:

The results show conclusively that the cable of Type C of this disclosure has three times the potential life of either of the other two types of cables that are now commercially available and previously identified as A and B cables. It should be noted Cables C1 and C2 .were still functioning when they were removed from the test stand. Upon their examination, it was estimated that the expected life span approaches 15,000,000 electrical cycles. The test simulated actual automotive production line conditions by using a special machine that can repetitively duplicate the many mechanical motions performed by the welding .gun operator while using a portable w`elding tool to spot weld auto body components -along a moving assembly line. The electrical testing was concurrently performed on the cables While they were subjected to mechanical iiexing motions. A constant load of 18,000 amps was maintained at 200 times per minute consisting of 4 weld cycles or 22.2 duty cycle. A sufficient water pressure differential was chosen at the beginning of the test in order to permit 2 GPM of coolant flow and thereafter maintained at this level. Inlet iow temperature was maintained at 75 and the conductivity and water Hows allowed to vary decreasingly in accordance with the cables rate of deterioration until total failure resulted.

Although the novel -cable of the present invention has identical construction both at the gun end and transformer end, these respective ends have different types of failures and, in practice, there is no system for confining the cables usage to a transformer end or a gun end. It must be interchangeable for both ends, and must be used by unskilled personnel.

It will be apparent from the foregoing description that the nylon collar and the manifold connector grooves are not important at the transfo-rmer end, but become rvitally necessary at the gun end for achieving (1) mechanical Wear and (2) water balance in the cable.

Therefore, the ends of the cable are built symmetrically although some functions of the components are not important at one or the other end of the cable.

What I claim is:

1. A connector unit for an alternating polarity watercooled electric welding cable, comprising in combination a flexible collar surrounding the cable in the vicinity of each end of the cable thereby providing a circumferential bearing surface for the cable ropes; an internally loc-ated support element in the form of a centrally bored body having helical grooves in its periphery, each of said 4grooves supporting one of the ropes constituting the cable; the helical angle of said grooves being approximately equal to the helical angle of the ropes constituting the cable, said flexible collar and internal body providing at the near end portions of the cable known to be susceptible to hot spots, sliding surfaces for the rope conductors enabling'free movement of the ropes and preventing chafng of the conductive wire strands of the ropes which would otherwise occur upon bending and twisting of the cable when in use; perforated tubular means located centrally of said cable for carry-ing coolant fluid introduced at the welding gun end of the cable and expelled at the transformer end of the cable; a first conductive connector element at each end of the cable for receiving `a plurality of ropes of one polarity, said connector having helically shaped rope-receiving body portions at least approximately equal in helical angle to that of the rope lay, said body portions defining a central space; a second conductive connector element at each end of the cable for receiving the ropes of the other polarity, said second connector being joined to said first connector in over-lapping relation thereto, said second connector element having aperture meanscentrally therein formed by a rounded body portion thereo-ver for fit into the central space of said first connector element.

2. Apparatus according to claim 1 inclu-ding a coiled metallic element located within said perforated tube, the coolant thereby being accessible to the cable rope elements at the hot region of the cable.

3. Apparatus according to claim 1 wherein said first conductive connector element has a circumferential manifold groove having end apertures and connecting with two spiraling flow channels to distribute coolant flow over the outer rope conductors of the cable, said manifold groove being supplied with coolant from the aperture at each of the manifold.

4. Apparatus according to claim 1 wherein said first connector includes a terminal connector tang insulated therefrom and` having a coolant flow space therebetween, the outer surface of said tang being in doubly beveled form; a conductive tank on said second conductive connector having an internal surface doubly beveled for close overlap tit with said first tang; and positive and negative terminal conductor elements insulated from each other and connected electrically to said first and second connector elements.

5. Apparatus according to claim 4 including a block separating said positive and negative terminal conductor elements, said block having aperture means therein in uid coupling relation with the central aperture means of said second connector element.

6. Apparatus according to claim 1 wherein each rope of the cable comprises 14 groups of strands consisting of 4 groups forming a core section and 10 groups forming a peripheral section surrounding said core section, said core strand groups being essentially elliptic-al in transverse cross section, adjacent strand groups of both said peripheral and core sections being alternately oppositely twisted, whereby there are provided six wear points in each of said groups, said core section being structurally stable to support the peripheral groups.

7. Apparatus according to claim 1 wherein the ropes of one polarity are located in essentially overlyingrelation to the ropes of the other polarity, said combina- 9 10 tion further including a sleeve separating the inner ropes References Cited from the outer ropes, said sleeve being formed of eX- UNITED STATES PATENTS ible electrically insulating material extending from said connector elements yat the cable ends for a longitudinal distance to accommodate by the volume thereof a pre- 5 determined proportion of liquid coolant flow to and away from the balance of the flow between the outer and inner LEWIS H' MYERS P "muy Exammer' conductors. H. HUBERFELD, Assistant Examine/' 3,065,290 11/1962 Grove 174-15 3,127,467 3/1964 Toto 174-15

Claims (1)

1. A CONNECTOR UNIT FOR AN ALTERNATING POLARITY WATERCOOLED ELECTRIC WELDING CABLE, COMPRISING IN COMBINATION A FLEXIBLE COLLAR SURROUNDING THE CABLE IN THE VICINITY OF EACH END OF THE CABLE THEREBY PROVIDING A CIRCUMFERENTIAL BEARING SURFACE FOR THE CABLE ROPES; AN INTERNALLY LOCATED SUPPORT ELEMENT IN THE FORM OF A CENTRALLY BORED BODY HAVING HELICAL GROOVES IN ITS PERIPHERY, EACH OF SAID GROOVES SUPPORTING ONE OF THE ROPES CONSTITUTING THE CABLE; THE HELICAL ANGLE OF SAID GROOVES BEING APPROXIMATELY EQUAL TO THE HELICAL ANGLE OF THE ROPES CONSTITUTING THE CABLE, SAID FLEXIBLE COLLAR AND INTERNAL BODY PROVIDING AT THE NEAR END PORTIONS OF THE CABLE KNOWN TO BE SUSCEPTIBLE TO HOT SPOTS, SLIDING SURFACES FOR THE ROPE CONDUCTORS ENABLING FREE MOVEMENT OF THE ROPES AND PREVENTING CHAFING OF THE CONDUCTIVE WIRE STRANDS OF THE ROPES WHICH WOULD OTHERWISE OCCUR UPON BENDING AND TWISTING OF THE CABLE WHEN IN USE; PERFORATED TUBULAR MEANS LOCATED CENTRALLY OF SAID CABLE FOR CARRYING COOLANT FLUID INTRODUCED AT THE WELDING GUN END OF THE CABLE AND

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