US1878790A - Electric flexible conductor - Google Patents

Description

ELECTRIC FLEXIBLE CONDUCTOR 7 Filed Dec. 8, 1928 4 1:"; I II Q 7 I II 22911100111 fl/III: [11/ VII Sheets-Sheet l Sept. 20, 1932 E. LUND ELECTRIC FLEXIBLE CONDUCTOR Fil ed Dec. 8, 1928 4 Sheets-Sheet 2 Sept. 20, 1932. g; LU 1,878,790

ELECTRIC FLEXIBLE CONDUCTOR Filed Dec. 8, 1928 4 Sheets-Sheet -3 Sept. 20, 1932. E. LUND 1,878,790

. ELECTRIC FLEXIBLE CONDUCTOR Filed Dec. 8, 1928 4 Sheets-Sheet "4 Patented Sept. 20, 1932 UNITED ,STATES PATENT orna e.

EINAR LUND, OF NOTRE-DAME DE BBIALLTCON, FRANCE, ASSIGNOR TO SOCIE'IE DES ELECTRODES DE LA SAVOIE, OF PARIS, FRANCE, A CORPORATION OF FRANCE Emerald nnxinnn connucron.

Application filed December 8, 1928, Serial No. 324,816 and in France December 17, 1927.

M invention relates to an electric flexible con uctor of the type which transmits high tension currents an the action of flame or jets of flame. I p

g T he"said flexible conductor is particularly applicable to leading an electric current to the movable electrodes of electrometallurgical furnaces of high power.

At the present ti e the flexible parts of the 1g elements leading current to such movable electrodes are composed of copper cables, or of flexible blades of copper, which have the dis advantage of being afle'cted by heat, oxidizing, and when Sub e'cted to annealing, of los- 16, ng their mechanical resistance. Also, in con-- nection with arrangements well known in the 'art, care is taken not to expose such elements to the flames given 011' byopen furnaces, such as calcium carbide or ferro-alloy furnaces for example.

In order to protect such current conductors against the flames of the furnaces, it has been proposed to increase their length, which causes not only an increase inweight of copv per brought into play but also a decrease in the power factor, and the latter disadvantage is particularly serious when it is'a' question of furnaces ofhigh intensity and low voltage in which a slight diminution in power factor causes an appreciable loss.

' My invention has for an object to overcome these disadvantages, above enumerated,

with a view to establishing at the same time,

the degree of flexibility desired and providing also an efficient cooling arrangement, which protects the conductors from flames and jets of flame. Another object of my invention is to combine one or more electric cables with a seamless flexible metallic tube of the type, for example, 0f those tubes which are formed by drawing a single piece of metallic tube, without soldering or clamping.

The one or more cables are preferably disposed with a certain amount of play within the flexible metallic tube. In certain cases I may dispose the metallic tube on the interior of the cable and I may even combine the two arrangements. In each case I provide a circulation of water or other liquid on the interior of the flexible tube with a view to en:

which is unaffected by surin cooling of theflexible conductor thus estab ished.

.the flexible conductor is connected.

The conductors thus constructed are both flexible and unaflected by the heat or by the flames issuing from the furnaces or elsewhere. Said conductors can at the same time conduct the cooling water and the electric current to the electrode-carrying devices or analogous members.

I shall describe hereinafter more in detail a number of constructional embodiments and fittings of flexible conductors of the type indicated, the said fittings being such as to ensure fluid-tightness to the greatest extent once the conductor is in place.

Likewise I shall hereinafter describe how I eliminate or at least reduce the phenomenon known as skin eflect.

In the accompanying drawings I have shown by way of example a number of nonlimiting embodiments of'my invention of diverse character illustrating the application thereof to flexible conductors leading current I to the electrodes of electro-metallurgical furnaces.

In the drawings Fig. 1 is a sectional view' of the first embodiment of my invention;

Fig. 2 isa sectional view similar to Fig. 1 showing a slightly modified form of mountg: Fig. 3 is an elevational view with parts in section of still another slightly modified form of mounting;

Fig. 4c is a partial longitudinal section of another modified form of conductor; F Fig. 5 is a transverse section taken through Figffi is a sectional longitudinal view of a modified form; V I

Fig. 7 is a partial sectional plan view of the same form and Figs. 8 and 9 are similar views of another modified form of mounting.

Referring to the drawings more in detail, mo

and particularly to Fig. 1, 1 represents a flexible seamles metallic tube, of any type known to the art, of an alloy 01' of copper, for example, formed of a single piece by drawing without soldering or clamping.

lVithin said tube is disposed a cable 2 of flexible character for conducting electricity, said cable being of such thickness as to form a space 3 between such cable and the tube for circulating water.

The cable 2 is fastened at each extremity within a bronze thimble 4, pierced by a transverse hole 5 and a longitudinal hole 6 for running water out of the tube. Each thimble is fixed by any of the well known means, such as threads, tapered joint, sweating, or the like, to an electric coupling 7 which may be cast or not, for ensuring clamping and perfect contact.

As shown in Fig. 1 said parts are screwthreaded together. The tube 1 is fixed to a socket 8 connected to a flange 9 of the coupling 7 and sealed by means of a suitable packing ring 10.

The couplings 7 can be connected either to the contact plate A with general water circulation surrounding the electrode B of the furnace and forming an electrodecarrying clamp therefor, or to the rigid bars C.

conducting electric current.

The couplings 7 are themselves each pierced with a channel 11 registerin at one end with the hole 6 of the thimble and communicating at the other end with a pipe line D serving as a conduit for carrying water to the electrode-carrying clamp A.

In Fig. 1, the two extremities of the flexible conductor are disposed vertically, and the movable extremity of the conductor can be displaced from the position indicated at \I in full lines to the position indicated at II in dot and dash lines, an arcuate rest 12, or analogous member serving to support the right hand end of the conductor.

In Fig. 2, the two extremities of the flexible conductor are horizontally disposed, with the movable extremity displaceable from po sition I to position II as before. In this figure bolts 13 with nuts serve to ensure, through the medium of plates 14 rigid with socket 8 and fitting 7, fluid-tight assembly of the various elements on the extremity of the con- 'ductor.

In Fig. 3, one of the extremities of the flexible conductor is vertically disposed whereas the other is horizontal, the horizontal end being displaceable as before from the position indicated at I to the position indicated at II. In said Fig. 3 only the lower clamping parts of bus bars C are shown.

In the modifications of Figs. 4 and 5, the cable 2 is maintained in spaced relation to the tube 1 by means of members 15 pierced with holes 16 in a manner to assure normal circulation of the water. The said members 15 asvavee may be metallic or of insulating material if it is desired to eliminate the phenomenon known in the electrical art as skin eflect.

With the same idea in mind, I may electricall-y insulate the tube 1, at one or both of its extremities, from the cable 2 as well as from the fitting7, in order to thus obtain, not only suppression of skin effect, but also to protect the conductor from jets of flame due to accidental contact.

The flexible conductor may be composed of one or more cables bound together in known manner for establishing the conditions desired, and chiefly in order to obtain the de cc of flexibility desired, for ensuring efliclent cooling, and for diminishing skin effect.

Figs. Sand 7 show the articulation of the water conveyor D on the conductor, by the intermediary of a knee joint 16 mounted on the fitting 7 to which the line 1 is connected. The electrical current is supplied by flem'ble plates 17, near to the center of the articulation and sheltered from the fire. The plates are fixed on the fitting 7 by bolts and connected to the bars C.

In Figs. 8 and 9, the same articulation is provided for the supply of water, but the current is conveyed by copper cheek plates 17 articulated on plates 18 fixed on the piece 7 7 and connected to the bars C.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. A fire-proof flexible electric conductor of the type described, comprising a flexible electric cable, a flexible metallic tube surrounding said cable, a fitting tightly fitted to one end of said cable, a packing member interconnecting said fitting and said tube, an aperture in said fitting for injecting water into the space between said tube and said cable, a fitting mounted on the other end of said cable, a packing member interconnecting said fitting and said tube, and an aperture in said last mentioned fitting adapted to pass the water in said space into an element to which said conductor is connected for cooling purposes.

2. A fire-proof flexible electric conductor of the type described, comprising a flexible electric cable, a flexible metallic tube surrounding said cable, a fitting firmly attached to one end of said cable and tube and having therethrough a channel adapted to pass water into the space therebetween, means for pivotally connecting said fitting to current-carrying bus-bars, and a fitting at the other end of said cable and tube having therethrough a channel adapted to pass the water in said space into an element to which said conductor is connected for cooling purposes.

3. An electricconductor of the type described comprising a relatively massive substantially solid electric conducting cable an outside flexible metallic tubing surrounding III the conducting cable and aced therefrom to form a water acket direct y surrounding the cable, a meta ic thimble fitted over each end of the conducting cable within the outside tubing and exten ing beyond the end of the tubing, said thimble being provided with a transverse channel or bore be 0nd the end of the cable within the water jac et and a longitudinal channel or bore communicating with the transverse channel and extending to the outer end of the thimble, and means sealing the water jacket near the end of the tubing.

4. An electrical conductor as claimed in claim 3 having an electrical end coupling fitted to the thimble outside the tubing.

In testimony whereof I have signed this specification. a

EINAR LUND.

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