US 867659 A
Description (OCR text may contain errors)
No. 867,659. PATENTED 001. s, 1907. W. HOOPBS & N. A. ROBERTSON.
APPLIOATION FILED MAY 11, 1906.
@f/M mam w UNITED j STATES PATENT OFFICE.
WILLIAM HOOPES, OF PITTSBURG, PENNSYLVANIA, AND NORMAN A. ROBERTSON, OF NEW YORK, N. Y.
sa as anllsatlm Juiar'y 10,1006,
Be it known that we, Win-rut floora's esiding in- Pittaburg, in the county of Allegheny and State of Pennsylvania, Norman A. Rosla-rson, residing in the borough of Brooklyn, in the county'of Kings, city and State of New York, both citizens of the United States, have jointly invented certain new and useful Improvements in Electric Conductors, of which the following is a specification. A
This-invention provida an improved wire rod, bar or the like, for conducting electricity:- The product is called a conductor herein, though it' is understood' tral section of a machine in which ,the extrusion of the that it may be appliedto othe- It is ll understood that aluminium. is fagood m ductor of electricity. It is, however, subjectto flaws which impair its tensile strength, and which, when it is strung in long spansand subjected to the weather conditions affecting aerial wires, result ultimately in transverse iractures; so that this deficiency limits its iron. It has been proposed to form a conductor with a core of copperand a shell of aluminium by casting aluminium around the heated copper coneto form a compoundv ingot from which the wire would down; but in practice it has been found impomible to produce such a conductor with either a copper or steel core, because the aluminium and the harder metal will not elongate equally inthe procem of reducing the ingot to'wire by the use either of dies or rolls, so that the result of an attempt to produce the compound wire or conductor is invariably to rupture one or other of the components thereof. The present invention provides a new and differe'nt product, in that the aluminium exists in the form produced by the process of extrusion through a die under heat and presure, whereby it hasproperties which are readily recognizable and which distinguish it from aluminium which is elongated or reduced by rolling down or wire drawing. Extruded aluminium is characterized by homogeneity, pliability, and freedom from cracks, fisures or ruptures; and in the case of a compound conductor having an inclosed core of stronger metal, it is further characterized by the extreme tightnem with which the aluminium embraces the core byreason of its shrinkage thereupon Y inicoolingf As compared with cast aluminium,-
of Letters 2atdnt.
Serial 1n. 241,109. new um!- quasus lay 11,1900.
Serial I0- amm.
Patented Oct. 8, 1907.
with difliculty, dragging over the tool, and forming granular chips and leaving a rough surface behind the tool; whereas extruded aluminium turns easily, forming a smooth cut, the chip coming off as a smooth uniform shaving.
The process of producing this conductor of extruded aluminium with an'inclosed core or reinforce, is set forth and claimed in our application filed January 16,-
1905, Serial No. v241,199 of which the present application is a division.
The accompanying drawings illustrate a variety cross-sections of the improved conductor, and a diamealuminium may be carried out.
I Figurcs'l, 2, 3, 5, 7, 8 and 9 are cross-sections of various forms of-eonductor. Fig. 4 is a central section thema chine." Fig. 6 is a perspective'view of the end of another form-of conductor.
In Fig. 1 the aluminium constituting the greater portion of the conductoris indicated at A, and the reinplied as requiring long or short spans.
A valuable feature of the invention is that the aluminium is shrunk on the core and fits it very tightly. The reinforcing wire is naked, and the aluminium fits it so closely as to be practically integral therewith close examination of the crom-section showing the line between the two materials only by reason of their difierence in color.
tallic and conductive contact, sothat the electric current may flow unrestrictedly from one to the other. The amount of shrinkage and the consequent intimacy of union is indicated by a comparison of Figs. 2 and 3. Fig. 3 indicates a conductor of aluminium extruded without a core, and therefore allowed to shrink to the full extent involved in its cooling. Fig. 2 indicates a wire extruded through the same die as Fig. 3, but with a steel core B which prevents the shrinkage of the aluminium except so far as to tightly embrace the core. By the process of extrusion the conductor can be made in continuous lengths, and can if desired be made hollow so as to increase its stiffnem and to adapt it for special uses, thus providing a cheap and efiicient substitute for the conductors now in use.
In the manufacture of the aluminium conductors described, a very great pressure is required. It is fou extrusion, it spurts or blows out through the die.
Thus the two metals are in meit cools below the point of liquidity it becomes more or less granular or crystalline in consistency, and at'this stage also the metal blows out instead of being squeezed out in a constant stream. This blowing is thought to be due to the gases which as is known aluminium absorbs in large quantities while molten. It is therefore necessary to work the process with the aluminium at a temperature below its crystalline stage when it has become so hard as to firmly imprison the gases and pretemperature. is indicated in Fig. 4, in which plungers C C work-in vent blow outs. This temperature necessitates maintaining the die and the'core of the machine (where such a core is used) at or preferably just below a dull red heat. The stiffness of the aluminium further ne-.
cessitates an extraordinary pressure, and the machine for extruding the aluminium must be designed to oppose the minimum of resistance to the flow of the aluminium, and to stand a very heavy pressure at a high A diagrammatic view of such a machine vertical cylinders D D which connect by oblique pas sages E E with the mouth of the die F into which the core G of the machine projects slightly; the reinforcing wire B being carried down through the center. The. die and the passages leading thereto (and when nec-' essary the cylinders) are maintained atthe desired. high temperature by suitable heating means, as by impinging-against the exterior the flames from a series of gas blow-pipes H. A
The metal (molten or in the form of slugs or otherwise) is introduced into the cylinders D. If introduced molten, it is allowed to cool to the necessary temperature. If solid, .it is heated to that temperature before introduction. The plungers C are then forced into the cylinders, preferably by raisingthe cylinders by hydraulic pressureagainst fixed plungers overhead, in the-known manner, and the aluminium is forced down through the converging passages E at the junction of which thestreamscoalesce, and thence but through the'die F, forming the body portion A of the conductor, and carrying with it the reinforcing wire B. As soon as the aluminium passes out 9f-.the constricted portion of .the die it commences to cool and shrink. The amount of shrinkage is controlled by the position of the end of the core G in the'die.
The reinforce ,may be much varied in form. By distributing the same amount of reinforcing material at a distance from the'center of the conductoi, 'it will produce a stiffer product than where it is all concentrated at'the center. Or by dividing the reinforcing material into a plurality of wires and extending them spirally, greater flexibilty may be secured. Fig. 5 shows the reinforcing material in the form of three separate wires B arranged about halfway between the center and the circumference of the cross-section. These wires B may extend straight or spirally. If straight they will stiffen the conductor in the manner of a' truss when itis supported at two opposite ends. If spiral, they make a more flexible conductor. Fig.6 shows the reinforcing wires :13 twisted together at the center of the conductorsoas'to extend spirally through it, thus giving approximately the flexibilitywhich a wire rope would have as compared with a rod of the same material and cross-section. The desired variashape desired.
- forced by a longitudinal core of stronger metal.
longitudinal core of stronger metal. the aluminium tightly "wire and a tubular envelop of extruded aluminium intions in the spacing of the separate reinforcing wires senate maybe made by suitable modifications of the core of, the machine'thr'ough which the reinforcing wire or wires pass. The advantage of using a plurality of wires of the stronger nietal may be secured as well with a conductor of other materials as with the con-- ductor of aluminium described.
The shape of the conductor a whole may be 'inodificd to suit the uses to which it is to be put, by a suitable modification in the shape of the die. For example in Figs. 7 and 8 cross-shaped forms A are illustrated', and in Fig. 9 a form A which is oblong in secas indicated at B? in 8,-or may. be ofany other The term aluminium is usedghe re in a general sense as applied also to alloys'composed so largely of aluminium as to partake largely of its properties. I For example an alloy of 90 parts aluminium, 8 parts copper, and 2 parts zinc, may be substituted for pure aluminium. It is also within the invention to include additional elements in connection 'with the metals described. I 1 I The term iron as hcrehised includes all forms of iron or steel. There is a special advantage in the condoctor having an iron core, in that the high tensile strength of iron can be utilized while its durability is securedon account of the protection from corrosion. The extruded aluminium covers the iron perfectly and preserves it'indcfinitely.
' Though we have described our invention with great particularity of detail, yet itis not tobe understood that the invention is limited to the specific embodiments disclosed. Various modifications thereo f\may be inade by those skilled in the art, without departure from thezinventi'on. 7
What we c1aim.is:. 10C
1. A continuous conductor of extruded aluminium rein- 2. A conductor of extruded aluminium reinforced by a embracing the core. v I 10' 3. A conductor of aluminium reinforced by a plurality of longitudinal wires of stronger metal.
'4. A conductor of extruded metal reinforced by aplurality of longitudinal wires of stronger metal spacedapart from each other.
5. A conductor of extruded metal reinforced by a plurality of longitudinal wires of stronger metal extended spirally.
,6. A continuous conductor of extruded aluminium reinforced by a core of iron surrounded and protected by the 11. aluminium. y
7. A continuous conductor consisting of a core of naked iron, wire and a tubular envelop of extruded aluminium inclosing said core in metallic contact therewith.
8. A continuous conductor consisting of a core of iron '1 closing and tightly embracing said core'in close, conductive metallic contact therewith.
In witness whereof. we huv'e hereunto sighed our names in the presence of twosubscrlbing witnesses.
- WILLIAM HOOPES.
Witnesses l 1:. '1. Dxxr-orrrrr, B. E. \Vl'rm-ms, Jr. 4 1
lflOlDIAN A. ROBERTSON. Witnesses: I
Donn-op A. UsINA, Fnsn 'm'rn.