US408875A

US408875A - Mark w

Info

Publication number: US408875A
Authority: US
Publication date: 1889-08-13
Anticipated expiration: 1906-08-13

Description

(No Model J.

M. W. DEWEY.

METHOD OF ELECTRIC METAL WORKING. I No. 408,875. Patented Aug. 13, 1889.

ATTORNEYS UNITED STATES MARK XV. DEM EY, OF SYRACUSE, NEXV YORK, ASSIGNOR TO PATENT OEEIcE.

THE DElVEY CORPORATION, OF SAME PLACE.

METHOD OF ELECTRIC METAL-WORKING.

SPECIFICATION forming part of Letters'Pat-ent No. 408,875, dated August 13,1889. Application filed ilune 3, 1889. Serial No. 812,973. (No model.)

To aZZ whom it may concern- Be it known that I, MARK WV. DEWEY, of Syracuse, in the county of Onondaga, in the State of New York, have invented new and useful Improvements in the Method of Electric Metal-\Vorking, of which the following, taken in connection with the accompanying drawings, is a full, clear, and exact description.

My invention relates to a new method of IO metal-working, in which both the heatingpower of the electric current or currents and magnetism are utilized. The magnetism is for the purpose of creating electric stress or resistance in the metal at the part desired [I 5 to be heated, and the electric current for heating the partwhere the resistance is created.

In electric metal-working, particularly inv operations appertainingto upsetting, separating, or forming metal bars or plates intermediatc of their length into various shapes, an enormous volume of current is required to raise the metal to a suflicient working temperature, especially when said -bars or plates are of large cross-section and offer a very low resistance to the current. On account of the low resistance of the bar it is necessary,

in order to locate the heat in the same, to make the other portion of the circuit of very large red or cable of superior conductivity.

3o This rod or cable is usually made of copper, and because of its expensiveness the current generator or transformer must be located in the immediate neighborhood of the operations.

As the heating effect of an electric current in a conductor depends not only upon the volume of the current but also upon the resistance of the conductor, the greater part of the heat of the current will be located in that part of the circuit having the greater resist- 4o ance. In welding operations the resistance can be more easily attained, as the imperfect contact between the two pieces creates the resistance required; but when a large continuous bar of metal of good conductivity is to be heated intermediate of its length it is necessary, as beforev stated, to form the other portions of the circuit of conductors of lower conductivity than the bar and generate an immense volume of current in the circuit. A

very small increase of resistance in a part of a low-resistance conductor will aid greatly in developing the heat generated by a current in the conductor at that particular part. Therefore by increasing the resistance by subjecting the 'part to be heated to magnetism or magnetic stress I am enabled to heat a larger bar with a given current and size of conductors connected to the bar than heretofore; or

it is possible to heat abar of metal with less current and smaller orless expensive conduct- 6o ors than by the usual method. The resistance effect depends of course upon the strength of the magnetism and the arrangement of the poles of the magnet in relation to the bar or blank, which relation in turn depends upon the nature of the metal. Greater effects are found in paramagnetic metals,'as iron, nickel, &c. but good effects are found in diamagnetic metals when the poles of the magnet are arranged in proper relation to the blank of such metal, as hereinafter described.

With iron or nickel the magnetic effect is m'l when the iron isheatedto redness ,butthe source of magnetism (the magnet) may be removed then or before this temperature is reached, as it has accomplished its purpose by creating stress or resistance, and thereby locating the heat in a part of the blank which may then be heated still more, if desired, for the heat itself has produced the required re- So sistance in the bar, which resistance will be maintained and increased by continuing the supply of current. The magnet is removed when its effect is m] or no longer necessary, for the purpose also of relieving it from the 8 5 intense heat, and removing the obstruction which it would form during the further Working or treating of the blank. In some diamagnetic metals the magnetic effect is continued during the entire heating operation to retain the resistance at the part heated, otherwise the part would tend to become cooler upon continuing the application of the current. Again, in order to locate the heat at a particular portion of the in etal-bar, the clamps 9 5 have heretofore been placed at each side of the part and the entire portion of the bar be tween said clamps has been heated. This is obj ectionable in many cases, as when the clamps are placed close together, in order to I00 locate the heat in a small portion of the bar that requires a forming, shaping, or other operation, while the current is still flowing andv the clamps are in the aforesaid position. This difficulty is obviated by my method, which allows the clamps to be widely SOPZULtOtl on the bar, the heatlocated at any point or points along the said bar between the clamps, the same being, preferably, flexibly connected with the circuit, and permits of free and unhampered working of the heated portion, and, further, the clamps themselves are not overheated.

My invention consists, essentially, in subj ecting the entire cross-section of a blank to a magnetic held of uniform strength, and sim ul taneously therewith passing through the blank, including the said i'nagnetized part, an electric current of suilicjient volume to soften the said part, and then working or treatin the part as desired; or it consists in subjecting the part of a blank to be worked or otherwise treated to a magnetic held and simultaneously therewith subjecting the blank, including the said part, to the heating action of an electric current of suitable volume flowin g in a direction different from the direction of the lines of force in the said. magnetic field, and then working or treatingthe said part as desired; and my invention further consists in subjeclin the part of ablank to be worked or otherwise treated to a llllgllOlQlO field, and simultaneously therewith subjecting the blank, including the said part, to the heating action of an electric current of suitable volume, having its direction at rightangles, or substantially at right angles, to the direction of the lines of force in the said magnetic field, and then working or treating the said blank as desired.

In the accompanying drawings, liigure 1 illustrates one of the arrangen'ients for accomplishing the herein described method, wherein alternatingcurrents are supplied both for magnetizing and heating the bar. Fig. is another form of the same wherein the alternating currents supplied to the magnets are rectified or straightened. Fig. 23 shows a magnet with a laminated. core that may be used when alternating currents are employed. Fig. =1: shows the poles of a magnet shaped to correspond to the form of the bar. l ig. shows a permanent magnet applied to a bar; l ig. (3, another arrangement of the magnet in relation to the bar; lJig. 7, an electro-magnetic tongs. Fig. 8 shows the arrangement of a bar having an OIllHl'gOlllOllli to be heated above the temperature of the neighboring portions between theclainps, and Figs. fl and 10 show two elevations of apparatus for mag netizing a plate.

ieferring specifically to the drawings, A in Fig. 1 .I'CPI'CSClllS an alternating dynanu), A and A the comluctors leading therefrom, including an adjustable resistance ii to regulate the current, and the primary coil of an ilHlllCliOllfll transiknmer As usual with such apparatus, theprimary current is oi. high tension and small volume, and istransformed by a suitable transforimnf into a current having opposite qualities-awn, low tension and great volume which flows in the secomlary circuit C of saidtransformer. The said transformer is in this case the source of the heating-current. D is the bar or blank of metal to be heated and worked, and is connectedby suitable clamps c-iin this case (1 and. (-.with the terminals of the secondary circuit, which is preferably formed of a flexible conductor or comluctors of low resistance. l is an elec ire-magnet arranged. with its poles on oppo site sides of the bar at or near the point to be heated. The object in thus arranging the poles of the magnet in relation to the bar is to change the position ol. the molecules in the bar, so that they will lie. in a position dill'erent from that in which the current places them. (L and a are the coils of the magnet, and are shown in a shunt-circuitl! of the primary circuit. f is an. adjustable resistance in the shunt to control the current therein. The upper pole of said n'iagnet and coil. (1 is made adjustable vertically, so that the poles may be separated more or less to admit bars between them of different. diameters. Although the poles may come in contact with the bar, better effects are obtained when they do not touch the bar, but are held in close proximity to the same, as shown. liy increasing or diminishing the current in the shunt or separating the magnets more or less the resistance may be regulated as desired.

Fig. 3 is the same as llig. l, with the I'olh'nw ing exceptions: The current of the magnet is rectified or straightcnedv in any suitable man ner, preferably as shown in patent to Westinghouse, No. 3713,0 35, dated November s, lStW. G indicates the straightening device. The magnet is sulfiported adjustably in. any suitable position in relation to the bar, aml may be removed entirely, when desirm'l, by means of the jointed arm b. ()no of the clamps is stationary, and the other 0 mover bio and flexibly c n'|ieeted with the secondary circuit so that if endwise pressure or drawing or pulling is the operation to be per" formed upon thebar after it is heated it may be accomplished by moving the clamp c by meansof the screw d. It will be obvious that both the transformer and reetiiiinti may be dispensed with when a continuous direct hcating-current is employed, and also that the magnets maybe supplied with current from a separate source from that supplying the heating-currenl.

Fig. 53 shows an eleetrommgnet having a laminated core 0 and a single cell (I and bar 1) in. position. it is )l'(3i t)l'l'(,(l. to have the core laminated or formel'l of insulated wires when the magnet is energixml by alternating currents, so that the core will not become heated.

Fig. 4 shows the magnet provided with polepieces 1' i, shaped to correspond to the forn1- other figures, where the poles of the magnets are at diametrically-opposite sides of the bar. Better effects can be obtained with some metals, especially diamagn etic metals by this or a similar arrangement, as the molecules are then in a position to offer the greatest resistance to the current.

Fig. 7 shows a pair of tongs provided with coils a and a, forming an electro-magnet, and a bar D in position between the poles.

Fig. 8 represents a bar or blank. D, eonnectcd with clamps c and c, and flexible connections g g, so that the bar while in circuit and the current flowing through it may be handled, forged, and worked as desired operations that could not be effected when held in the apparatus shown in Fig. 2such as twisting, bending, the. The said clamps or electrical connect-ions .in this case are not rigidly connected with each other, as shown in Fig. 2, but are capable of universal movement independent of each other to allow the blank to be handled and formed in any desired shape while connected with the clamps. The bar, when thus flexibly connected in the circuit, may be held while heated by suitable insulated supports, clamps, or tools, stationary or movable. The figure also represents an enlarged portion h of the bar desired to be heated in excess of the other portions of .the bar between the clamps in position between the poles of a magnet.

Figs. 9 and 10 represent two views of an elongated electro-magnet for magnetizing a plate to be heated and worked, Z and Z indicating the conductors of the heating-circuit.

It will be obvious that it may be advantageous to employ magnetism in some cases for all forms of electric metal-working, ineludin g welding, tempering, &c.

For the sake of simplicity, it will be suflicient for the purpose of this invention to suppose that in all cases magnetizing the conductor causes the same to offer higher resistance to the current, and although it may be ultimately found in some cases to have the opposite effect, yet in all cases said magnetization will localize the heat produced by the current at or near the altered part, and, as is well known, after the heat is once located it will itself offer an increased resistance to the current and rapidly develop itself.

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

1. The herein-described method of metal working, consisting in creating electric stress or resistance in a continuous metal bar or blank by subjecting the blank at or near the part to be worked to magetism and simultaneously therewith passing through the blank, including the said part, an electric current of sufficient volume to soften the said part, and then bending, shaping, or otherwise working or treating the part.

2. The herein-described method of metalworking, consisting in subjecting the blank at or near the part to be worked to the action of a magnetic field and simultaneouslytherewith subjecting a portion of the blank, including the said part, to the heating action of an electric current of sufficient volume to heat the said part, removing the source of magnetism when its effect is all, and continuing to supply said current until the part is sufficiently softened. and then working or treating the said part as desired.

3. The method of metal-working, consisting in creating electric stress or resistance in a metal bar or blank connected in circuit by subjecting the part of a blank to be heated and worked or otherwise treated to magnetism and simultan eously therewith passin gthrough said blank, including the said part, an electric current of suitable volume, and then working or treating the said part as desired.

4. The method of metal-working, consisting in subjecting the part of ablank to be worked or otherwise treated to a magnetic field and simultaneously therewith subjecting the blank, including the said part, to the heating action of an electric current of suitable volume flowing in a direction different from the direction of the lines of force in the said magnetic field, and then working or treating the said part as desired.

5. The method of metal-workin g, consisting in subjecting the part of a blank to be worked or otherwise treated to a magnetic field and simultaneously therewith subjecting the blank, including the said part, to the heating action of an electric current of suitable volume, having its direction at right angles, or substantially at right angles, to the direction of the lines of force in the said magn etic field, and then working or treating the said blank as desired.

(3. The method of metalworking, consisting in subjecting the entire cross-section of a blank at or near the part to be heated and worked or otherwise treated to a magnetic lield and simultaneously therewith subjecting the blank, including the said part, to the heating action of an electric current of suitable volume having its direction at right angles, or substantially at right angles, to the direc tion of the lines of force in the said magnetic field, and then working or treating the said blank as desired.

7. The method of in etal-workin g, consisting in creating electric stress or resistance in a metal bar or blank by subjecting the entire cross-section of a blank to a magnetic field of uniform strength and simultaneously therewith passing through the blank, ineludin the magm'itized part, an electric current of sufficient volume to soften the said part, and then working or treating the part as desired.

8. The method of metal-workin g, consisting in connecting the blank to be heated and worked in a circuit by independent universally-movable connections, passing an electric current through the circuit of sutlicient volume to heat or soften the blank, and then moving said connections and handling and working the blank as desired.

$1. The method of metal-working, consisting in clamping, by independent universallyanovable clamps, the bar or blank of metal. at two points, leaving-a section of themetal. between the clamps, connecting the clamps by flexible lo\\'-resistance conductors with the source of heating-current, passing an electric current through the flexible conductors, clamps, and section of metal between them, so as to soften the metal, and then moving said clamps and handling and working or treating the blank as desired.

10. The method ofmetal-werking, consisting in clamping the bar or blank of metal at two points, leavingasection of the metal between the clamps, flexibly connecting the clamps by flexible lo\\'-resistance conductors with the source of heating-current,subjecting the metal between the clamps to magnetism and. simul taneously therewith passing an electric current through the flexible conductors, clamps, and section of metal between them, so as to soften the metal, and then handling and workin g or treating the blank as desired.

1.1. The method of metal-working, consisting in creating resistance to the electric current in a metal bar or blank at or near the part to be heated and worked, passing an. electric current through the bar or blank ot' suflicient volume to soften the same at the part wherein the resistance is created, and then working the blank as desired.

12. The method ofmetal-working,consisti ng in flexibly connecting the bar or blank to be heated 'and worked in an electric circuit, crez'tting resistance to the electric current in the bar or blank at or near the part to be heated and worked, and mssing an electric current through the said baror blank ot' snl'iicient volume to soften. the same at the part wherein the res'stance is created, and then handling and working the blank as desired.

In testimony whereof I have hereunto signed my name this 31 st day of May, 1889.

\Yitnesses:

( ll. 'DUELL, II'. 'M. SEAMANS.