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Publication numberUS3811311 A
Publication typeGrant
Publication dateMay 21, 1974
Filing dateApr 7, 1972
Priority dateApr 7, 1972
Publication numberUS 3811311 A, US 3811311A, US-A-3811311, US3811311 A, US3811311A
InventorsA Barone, Ascoli R D, C Bechle
Original AssigneeAnaconda Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Making flat copper-clad steel wire
US 3811311 A
A more uniform cladding thickness is retained on flat copper-clad steel wire by drawing the first rectangular sections, rather than rolling them, from round wire, and then rolling the final flat wire.
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Description  (OCR text may contain errors)

United States Patent [191 Barone et a1.

[451 May21, 1974 1 MAKING FLAT COPPER-CLAD STEEL WIRE [75] Inventors: Angelo P. Barone, Sycamore, 111.; I Ralph G. DAscoli, Yonkers, N.Y.; Charles W. Bechle, Sycamore, 111.

[73] Assignee: The Anaconda Company, New

[58] Field of Search 72/274, 47, 700, 377, 467, 72/282, 278, 365, 366; 29/D1G. ll, DIG. 32

[56] References Cited UNITED STATES PATENTS 2,286.759 6/1942 Patnode 72/366 Aug e 29/173 2,134,014 10/1938 Whitehead 72/700 2,268,617 1/1942 Pierce 72/47 2,146,788 2/1939 B10unt.. 72/467 1,813,539 7/1931 Hurley.. 72/700 2,152,842 4/1939 Evans 72/47 1,922,770 8/1933 Kornbrath 72/282 Primary ExaminerCharles W. Lahman Assistant Examiner-M. J. Keenan Attorney, Agent, or Firm-Victor F. Volk [5 7] ABSTRACT A more uniform cladding thickness is retained on flat copper-clad steel wire by drawing the first rectangular sections, rather than rolling them, from round wire, and then rolling the final flat wire.

6 Claims,' 3 Drawing Figures PATENTEflmm 1914 3.811.311

PRIOR ART 9 allllll) Fig. 3

BACKGROUND OF THE INVENTION Copper-clad steel wire is known to combine the advantages of the high tensile strength of steel with the high electrical conductivity, and resistance to corrosion of copper. In spite of the fact that electroplating of copper has long been practical and economical for most purposes, for electrical conductors, it has been most advantageous to draw down a hot-rolled casting of a copper ingot around a steel core. This is due to the superior bonding of the copper and'steel in such a structure and to the fact that the economy of electroplating is lessened for greater wall thickness of copper. Copper-clad steel wire has been standardized by conductivity in American Society for Testing Materials (ASTM) Standard Specificaton B 22 7-70. This standard requires that the thickness of copper cladding of grade .40 HS shall be no less than 12 mils on a wire 0.2 to 0.21 inch in diameter. The thickness of cladding of an 0.09 inch wire is required to be no less than mils. It should be noted that the expression copper-clad steel as used by ASTM, and in this application, is not limited to the cast ingot method of forming the clad product, and other methods, such as high current density plating and hot swaging have been known.

To make square copper-clad steel wire it has been usual to cold-roll the standard round wire. However, where it is desired to obtain flat copper-clad wire, such as wire having the long dimension of its section at least four times the short dimension, it is found that cold rolling preferentially rolls the copper to the edges and leaves inadequate protection on the flats.

SUMMARY We have discovered that a flat copper-clad steel wire can be made with good distribution of the copper over BRIEF DESCRIPTION OF THE DRAWING FIG. 1 shows a section of prior art rolled flat wire. FIG. 2 shows a series of wire sections of flat wire formed in the steps of our method.

FIG. 3 shows the steps in the method of our invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT FIG. I represents prior art efforts to roll copper-clad steel flat, the flat section 11 with a steel core 12 and copper cladding 13 having been rolled in a series of passes from a round copper-clad steel wire such as the wire 14 (FIG. 2). Rolling has had the effect of pushing a disproportionate amount of the copper to the edges 16, 17 and of leaving an irregular cladding with thin spots, such as 18, on the surface having the longer dimension. Examples 1, 2.and 3 below illustrate the results of rolling copper-clad steel wire, of grade 40 HS ASTM B 227-70.


Size of initial round wire, inch 0.170 0.170 0.161 Number of rolling passes 2 3 2 Final long dimension, inch 0.2445 0.2460 0.2445 Final short dimension, inch 0.0507 0.0507 0.0507 Maximum copper on edge, mils 22 23.6 23.7 Maximum copper on flats, mils 8 7.8 6.5 Minimum copper on flats, mils 3.3 3.7 3.2

When, instead of being rolled, the round wire 14 was drawn through a series'of wire drawing dies 19, 20, 21, 22, 23 (FIG. 3) to the respective sections 24, 25, 26, 27, 28 and was only then rolled, in a single pass, to a section 29, it was found to have the improved cladding distribution of EXAMPLE 4. In this case the thickness of cladding was about 18 mils, 6.25 percent of the wire diameter.

EXAMPLE 4 Size of initial round wire, inch 0286 Number of rectangular dies 5 Number of rolling passes 1 Final long dimension, inch 0.2440 Final short dimension, inch 0.0507 Maximum copper edge, mils l5.4 Maximum copper on flats. mils 7.9

Minimum copper on flats. mils If, instead of drawing in a single pass, the wire is taken up after each die passage, a wide choice of reduction ratios may be made but the cost of the drawing operation will be increased prohibitively for most commercial purposes, although still falling within the scope of our invention.

Starting with a 0.286 inch diameter wire having an area of section of 0.0642 square inches, we have found it advantageous to select the dies 19, 20, 21, 22, 23 to provide respective sectional areas of 0.0475, 0.036, 0.02765, 0.02135, and 0.01667 square inches, the final section, 28 from the die 23 being 0.090 X 0.205 inch. After rolling to 0.050 X 0.245 inch the section 29, which retains rounded corners, has an area somewhat less than 0.01225 square inch. In this embodiment the ratio of the long dimension to the short dimension of the section 28, i.e., the width to the thickness, is 2.28 to 1 and the ratio for the rolled section 29 is 4.9 to 1. The minimum thickness of cladding of the flat section made in EXAMPLE 4 is seen to be 5.6 mils which is over 10 percent of the thickness of the flat section. Where a precise control of the width of the section 29 is required the flat wire is passed through edge rolls which merely flatten the curvature of the copper on the edges, but do not affect the steel. Such edge rolling, which accounts for some squaring of the edges of the flat section 29 of FIG. 3 is not an element of the novelty of the present invention.

Wehave invented a new and useful method of which the foregoing description has been exemplary rather than definitive, and for which we desire an award of 3. The method of claim 2 wherein the longer dimension of said'rectangular section after drawing but prior to rolling is at least twice the shorter dimension of said section.

4. The method of claim 1 wherein said cold drawing into a rectangular section is effected through a plurality of dies in a continuous run.

5. The method of claim 3 wherein said cold drawing into a rectangular section is effected through a plurality of dies in a continuous run,

6. The method of claim 2 wherein said longer dimension exceeds the longer dimension of the final of said rectangular sections after drawing but prior to rolling. =l

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1813539 *Mar 12, 1927Jul 7, 1931B G CorpMethod of rolling composite wire
US1922770 *Mar 16, 1929Aug 15, 1933Union Drawn Steel CompanyDrawing die
US2134014 *May 25, 1935Oct 25, 1938Copperweld Steel CoMethod and apparatus for rolling bimetallic articles
US2146788 *May 20, 1936Feb 14, 1939Western Electric CoWire-drawing die and method
US2152842 *Aug 23, 1934Apr 4, 1939Evans Martin EMetal attenuating process and apparatus
US2268617 *Nov 1, 1938Jan 6, 1942Nat Standard CoMethod of making copper clad wire
US2286759 *Nov 18, 1940Jun 16, 1942Gen ElectricMethod of making insulated wire of small or irregular cross-section
US3645123 *Sep 2, 1969Feb 29, 1972Andre AugeProcess for making metallic wires and metallic wires prepared thereby
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3940964 *Oct 1, 1974Mar 2, 1976Matsushita Electric Industrial Co., Ltd.Method for making a clad wire for an electric contact
US4552599 *May 8, 1984Nov 12, 1985Sumitomo Electric Industries, Ltd.Process for producing insulated rectangular wire
US4787228 *May 12, 1983Nov 29, 1988Kabel-Und Metallwerke Gutehoffnungshuette AgMaking molds with rectangular or square-shaped cross section
US6886385 *Aug 12, 2003May 3, 2005NexansMethod of continuous production of metal wires
US7617847Nov 29, 2007Nov 17, 2009Clerkin Thomas MApparatus and method for forming wire
US7628647 *Oct 23, 2007Dec 8, 2009Sumitomo Electric Industries, Ltd.Coaxial cable and method for manufacturing the same
US8826945Nov 13, 2009Sep 9, 2014Thomas M. ClerkinApparatus and method for forming wire
DE4435402A1 *Oct 4, 1994Apr 11, 1996Thyssen Draht AgVerfahren zur Oberflächenbeschichtung von Profildrähten
EP1393828A2 *Jul 17, 2003Mar 3, 2004Nexansmethod for continuous production of metal wires
U.S. Classification72/278, 72/700, 72/47
International ClassificationB21C37/04, B23K20/00
Cooperative ClassificationB21C37/042, Y10S72/70, B23K20/00
European ClassificationB23K20/00, B21C37/04B
Legal Events
Jan 18, 1982ASAssignment
Effective date: 19820115