US2250610A - Wire and wire making - Google Patents

Description

July 29, 1941. s s 2,250,610

WIRE AND WIRE MAKING Filed Dec. 6, 1938 MORRIS S/MO/VS ATTORNEYS L INVENTOR Patented July 29, 1941 UNITED STATES WIRE AND WIRE MAKING Morris Simons, litid'gefield, Conn. Application December 6, 1938, Serial No. 244,149 11 Claims. (CI. 29-33) This invention relates generally to the manufacture of wire, and has for its principal purpose the production of a wire which is better than prior wires of the same material and diameter in that the tensile strength and percent of elongation are greatly increased. For example, in some instances the tensile strength of a wire has been increased more than 20 percent by making it according to the present invention.

In the manufacture of wire a billet of metal such'as iron, steel or brass, is heated to the temperature where the metal can be worked to the best advantage. Usually the billet employed is about X 5" x 36". After the billet reaches the desired temperature it is passed through the various roll passes of a rod mill each of which compresses and works the metal and at the same time elongates it until at the final passthe billet has been converted into a round rod of from A inch to inch in diameter according to the final product desired. This rod is, at the end of the reducing operation, wound on a large spool or reel and is in that form transported to the wire drawing apparatus.

The successive working of the metal down to the final stage before it is wound on the spool results in the rod having a texture which may be described as consisting of parallel fibers or flow lines with the grains of the metal greatly elongated. The tensile strength of the wire varies according to the kind of metal, but in all; of the metal produced as above described and used for wire making this condition may be seen by microscopical examination. In other words the raw stock ready for the wire drawing apparatus may be visualized as being something in the nature of a collection of parallel wires joined together along their sides.

The tensile strength of a rolled rod is being increased by various passes through dies and is being achieved through the compression of the long fibres when passing through a die, at the same time making the metal harder but doing it at the expense'of the elongation factor. In other words, the harder the metal becomes the less elongation is found in that hardened metal.

The invention consists in twisting such a rod so asto give somewhat the same effect with respect to these parallel fibers as results from twisting wires together in forming a wire cable, so that load stresses are taken up by and distributed among all of the fibers instead of only a part of them, thereby preventing what might be termed individual breaks in the fibers because some of them are put under greater strain than others.

In other words the load is taken by the fibers as a unit instead of individually.

The invention comprises one form of apparatus which is suitable for obtaining the result. While that form is highly satisfactory it is, as will be apparent later on, not the only one that can be used for imparting the desired twist to a rod which is to be drawn down to a wire. The method involved is new and the product is newand better in the respects above indicated than anything in the prior art with which the applicant is familiar.

In the accompanying drawing:

Fig. 1 shows in more or less diagrammatical form an apparatus for carrying out the invention.

Fig. 2 is in part the same as Fig. 1 but illus-- trates the use of a furnace for annealing the rod.

Fi 3 shows on an enlarged scale a wire produced according to the invention with the twist lines indicated diagrammatically.

Fig. 4 is a cross-section illustrating the construction of one of the drawing dies.

.The spool or reel of the raw stock to be used in drawing the wire is shown at 10, Fig. 1, and

the rod at H. The apparatus includes a frame 12 which can be constructed to receive a rod or support 53 passing through a hole through the center of the spool in. The frame I2 is formed mounted in suitable supports l5. One of the trunnions or bearings is extended far enough to have attached adjacent its end a sprocket connected by a chain IT to a driving sprocket or pinion, cooperating with the chain at the point l8, which may bein the armature shaft of a motor I 9 or part of a gear box through which the motor drives the sprocket and chain IT. The motor is preferably of the variable speed type. By this construction the frame l2 whatever speed is desired for the particular material being worked upon. It is to be noted that the axis of the spool or reel is at right angles or substantially so to the axis of rotation of the frame l2.

Within one of the trunnions M of the frame I! is a guiding die 2| which serves to center the rod 1| passing-through the die with reference to the wire drawing mechanism. The purpose of the rotation of the frame l2 and spool i0 is to twist may be rotated atusual type which are driven at successively increasing speeds and impart draft to the rod or wire through a plurality of turns taken by the rod or wire around the drums. While five drums 22-26 are shown it is obvious that the number may be varied according to the number of reductions to be made in getting the wire down to the desired gauge. The rod or wire is drawn by the drums through successively acting wire drawing dies 21, 28, 29, 30 and 3|, which may be of any standard or usual construction. As is well known such dies are rigidly held in supporting frame work and have their interiors shaped (as illustrated in Fig. 4) so as to compress, with consequent elongation, the metal that is drawn through them.

The first die 21 grips the rod tightly enough so that it limits the twist imparted to the rod by the rotation of frame l2. The distance between this die and the guiding die 2! may be varied according to requirements. The distance and speed of rotation are such that in making the twist there will be a full twist of 360 for each unit of length, the length of the unit depending on the material from which the rod H has been formed. In some instances afull twist can be made for each /2 inch of the rod length, while in others the full 360 twist cannot be made in less than 43/. inches without risk of damaging the metal in the rod.

The first die 21 not only holds the rod against rotation so as to limit the twisting efiect but it also serves to smooth and compress the rod as it is drawn through the die by thedrum 22, thereby giving the twist a permanent set in the rod which is maintained throughout the subsequent operations; the subsequent operations causing further reductions in diameter with resulting elongation of the metal as well as elongating the helix of the twist. The final product may have a twist in which there is a iull 360 twist, for example, for each 6 inches in length of the wire, but this will depend upon the initial twist between the die 21 and the point of tangential contact on the reel ID, as well as the subsequent elongation of the wire.

Some materials. such as the higher carbon steel wires, Everdur. Permalloy. and many other alloy wires, do not lend themselves readily to the twisting operation without first being softened slightly and for such metals it is advisable to use afurnace 35 which 'is constructed to provide a heat zone which is long enou h, and in which the heating agent may be regulated, so as to raise the rod to the desired temperature. This {urnace is not illustrated in detail because the xact construction is not essential. It is preferred, however. to use a furnace in which the rod is protected by a tube through which the rod passes while being heated, or a furnace containing a non-oxidizing atmosphere through which the heat is transmitted. There are a number of furnaces on the market which are suitable for the purpose.

In working with. for example, a high carbon steel rod of A inch diameter as the raw stock. the distance between thedie 27 and the exit of thefurnace 35 should be from 12 inches to 24 inches or-more in order to give the rod time to cool sufilciently before it enters the die. This distance is, of course. subject to variations according to the material being worked upon and according to the lubricant used at the first drawing pass. If, as is quite common, the rod. s althereafter the drawing operation is substantially the same as above described.

While the undoubted advantages gained in the way of greater tensile strength and a greater elongation factor appear to be due to what is in effect a twisting together of parallel fibers, it is not the desire to be confined to or limited by that theory. Regardless of the cause, in every instance Where wire has been made according to the invention of copper, iron, steel and copper-- coated iron or steel, a great increase in tensile strength and elongation was found and this important effect could not be accounted for in any other way by the applicant.

As a specific example of the result from using the apparatus and 'method hereinabove described, a A inch copper rod has been given a twist of substantially 360 for every /g inch of rod length and when this was drawn down to a wire of No. 13 gauge a full 360 twist for each 6 inches of the wire was found to exist in the wire, with an increase in tensile strength of over 10 percent.

It may, insome cases, be advisable to give the wire an additonal twist at an intermediate stage in the drawing operation. This can be done by drawing the stock down part way by an apparatus such as is illustrated in Figs. 1 or 2 and winding it on a spool, and then placing the spool in the frame l2 of a twister and repeating the twisting and drawing operation. The purpose in all cases is to get a wire with a twist in the metallic structure of as short a 360 helix per unit of length as is practicable without damaging the metal at any point in the twisting and drawing operation. a

In all of the twisting operations the reel or spool l0 carrying the supply of raw stock may, if desired, be braked or its rotation retarded by any of the usual mechanisms to control the tension on the stock, or tensioning devices may be applied directly to the rod ll.

2. The method of making a single stranded wire which comprises twisting a rod uniformly throughout its lngth, at least one complete twist being made for each twelve inches of rod length, and then cold drawing the twisted rod to down to the desired wire gauge.

3. A method of manufacturing wire from a wire rod which comprises drawing the rod by successive stages down to a wire of the desired final gauge by drawing through successively acting drawing dies, and progressively and continu- Oilsly twisting the rod at the entering side of the first die to supply for drawing a rod in which the metal is twisted.

4. A method of making a single stranded wire which comprises passing a wire rod through a heating zone, maintaining substantially a uniform degree of heat in said zone and a substantially uniform rate of passage of the rod through said zone, imparting a uniform twist to the heated portion of the rod, and drawing the twisted rod down to a wire of the desired diameter.

5. A method of making wire from a wire rod which comprises passing a wire rod through a heating zone, maintaining in said zone a degree of heat suflicient to anneal the rod, twisting the rod within said zone 360 for each twelve inches or less of the rod length, allowing the twisted rod to cool till it loses substantially its heat, and then drawing the twistedrod down to a wire of the desired auge. a a

6. As an article of manufacture, a metal single strand wire in which the fiow'lines of the metal are disposed helically in the body of the wire while drawing the wire to increase substantially two percent or more the elongation factor of the wire.

7. As an article of manufacture, a metallic single strand wire in which the flow lines' of the metal are permanently and uniformly disposed helically in the body of the wire to increase the tensile strength of the wire by cold drawing the wire down to the desired gauge from a uniformly twisted rod.

8. An apparatus of the character described comprising a support rotatable about a longitudinal axis and constructed to rotatably support a spool carrying coiled rod with the axis of the spool substantially at a right angle to the axis of the support, a wire drawing mechanism sup plied by drawing rod from the spool, and means for rotating the support to twist the rod between the support and the wire drawing mechanism.

7 9. An apparatus of the character described comprising a support rotatable about a longitudinal axis and constructed to rotatably support a spool carrying coiled rod with the axis of the spool substantially it a right angle to the axis of the support, a wire drawing mechanism supplied by drawing rod from the spool, and means including a variable speed motor for rotating the support to give a predetermined number of complete twists to each unit of length of the rod between the support and the wire drawing mechanism.

10. An apparatus of the character described comprising a support rotatable about a longitudinal axis and vconstructed to support a spool rotatable on its axis and carrying a supply of coiled rod, the axis of the spool being at a right angle to the axis of the support, a guiding die rotating with the supportand engaging the rod drawn from the spool, a wire drawing mechanism supplied by drawing rod from the spool, and means for rotating the support and spool to twist the rod as it passes between the wire drawing mechanism and the spool on the support whereby to supply uniformly twisted rod to the wire drawing mechanism.

11. An apparatus of the character described comprising a support rotatable about an axis and constructed to support a spool rotatable on its axis and carrying a coiled supply of rod, the axis of the spool being substantially at a right angle to the axis of the support, a guiding die rdtating with the support and engaging the rod as it is drawn from the spool, a wire drawing mechanism supplied by drawing rod from the spool, means for rotating the support to twist the portion of the rod passing between the aforesaid guiding die and the wire drawing mechanism, and a heating device between said grip and said mechanism for heating the rod sufliciently to facilitate twisting while leaving the metal undamaged.

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