US1386645A

US1386645A - Electrically-heated strip and wire tempering and annealing device

Info

Publication number: US1386645A
Application number: US325698A
Authority: US
Inventors: William E Moore
Original assignee: PITTSBURGH ENGINEERING WORKS
Current assignee: PITTSBURGH ENGINEERING WORKS
Priority date: 1919-09-23
Filing date: 1919-09-23
Publication date: 1921-08-09
Anticipated expiration: 1938-08-09

Description

I W. E. MOORE.

ELECTRICALLY HEATED STRIP AND WIRE TEMPERtNG AND ANNEALING DEVICE. APPLICATION FILED SEPT 23.1919.

' 1,386,645. Patented Aug. 9, 1921.

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ELECTRICALLY HEATED STRIP AND WIRE TEIVIPERING AND ANNEALING DEVICE.

APPLICATION FILED SEPT 23. I919.

1,386,645.. Pdtented Aug. 9, 1921.

2 SHEETS-SHEET 2.

Q I a I I I o I I i kw H o 2 :I- I r E III A E I 2 5 N 1m W5 a E, III-1| I Q I QM I I N o I w I fi N I T I' III I INVENTOR ATTO NEY j N TED STATES PATENT OFFICE.

WILLIAM E'KOBBE, 01 3mm FALLS, PENNSYLVANIA, LBSIGNOB TO THE PITTS- FUDGE ENGINEERING WORKS, TR01 YENNBYLVANIA.

PITTSBURGH, A CORPORA- mmomcmY-mun em mm mm rmnma'm mmnw mivrcn lpeclflcatlon o! fitter: Ietent.

Patented Aug. 9, 1921.

application am September as, 1019. Serial Io. 825,898.

To' all whom it may cmwem: 1

Be it known that 1, WILLIAM E. Moons, a

I citizen of the United States, residin at Beaver Falls, county of Beaver, and tate of Pennsylvania, have invented certain new and useful Improvements in Electrically- Heated Strip and Wire Tampering and Annealing Devlces, of which the following 1s a specification.

My invention relates to electrical tempering and annealing devices, and 1t consists 1n the constructions, combinations and arrangements herein described and claimed.

An object of my invention is to provide a device by means of which the heat ng and subsequent cooling of the stnp or wire may be more readily regulated and controlled than in fuel fired furnaces.

A further object is to provide an electrical machine by means of which a greater quantity of wire may be annealed o r tempered in a given time than by the ordinary processes.

which will produce a more uniform product, with less oxidation.

Other objects and advantages will appear in the following specification, and the novel I features of the invention will be particularly pointed out in the appended claims.

Themachine which formsthe sub ect of the present invention is designed for annealing or tempering wires and strips, as for instance, those used in wire rope, piano wire, strips, springs, safety razor blade steel, etc., and hereafter it will be understood that where the word wire is used, reference is made to wire sheet strip of any width, or strand.

My invention is illustrated in the accompanying drawings, forming part of this application, in which- Figure 1 is a plan view of a portion of the device; v h

Fig. 2 is a side view of the parts shown 1n Fig. 1;

fig. 3 is a plan view of the entire machine, an

Figs. 4 and 5 are side views of the parts shown in Fig. 3.

In carrying out my invention, I provide two machines A and B which are substantially alike. Each machine includes a base 1 upon which is mounted a frame 2 carrying A further object is to provide a machine a series of transverse shafts 3. 'At one end of each shaft is a flanged roller 4. One shaft of each machine bears a drive "pulley 5, the two pulleys 5 being connected together by a belt 6. T e machine A is also provided with a pulley 7 which is connected by means of a belt 8 w1th a reel 9. The tension on the belt 6 is re lated by means of a weighted idler 10, WhlCh allows the belt to slip when the allowed tension on the wire is exceeded.

The device is driven by a variable s eed motor 11, which is conveniently variable within the ratio of 4 to 1. A flexible coupling 12 which is preferably of an insulating type connects the motor 11 with a worm speed reduclng gear shown] diagrammatically at 13 on one of the shafts 3. Movement is imparted to the other shafts by gearmg 14 so arranged as to drive adjacent shafts 3 in opposite directions. The machine B has a similar arrangement of drivin gears 14.

The wire 15 is stored on a reel 16 and is fed to the flanged rollers of the machine B, these rollers constituting contact and tensioning devices, the wire passing under one wheel and over the adjacent one, as seen in the drawings, being thus frictionally i ped by the wheels. At the opposite emf oi the device the wire passes over and under the flanged rollers 3 of the machine A bein wound on the reel 9. The machine B is a justed to run slightly slower than the machine A to ive proper tension to the section of wire 15 etween the two machines.

. pass, as explained hereinafter. This tube is preferably lined with some 'heat insulating material as asbestos, not shown.

A transformer 22, with its primary coil '23 receiving high tension power delivers low tension power to its secondary 24, which is adjustable in voltage by a dial switch 25,

'one end of the secondary being connected to the metal portions of the machine B while the other is connected to'the machine A.

From the foregoing description of the various parts of the device, the operation thereof may be readily understood. The wire is drawn forward and the portion between the machine A and B is heated by the electric current. It is quite desirable to maintain the temperature of wire between machine B and quenching tank 17 or quenching wheels or rollers of the machine A at just the right temperature. Any excessive temperature tends to coarsen the grain and weaken the wire, while insufficient temperature does not give the proper tempering effect to the wires. I, therefore, prefer to maintain this temperature constant by means of an automatic regulator, operating by the variation of temperature in the wire to either adjust the speed of wire travel between the machines and, therefore, its temperature, or adjust the heating transformer voltage and, therefore, the temperature of the wire.

This may be done by any of the well known temperature indicating means as by a suitable thermostat or thermocouple adj acent to the wire, or for instance, by means of an expansion wire, which is ad acent to and heated by radiations from the wire being heated, and arranged to operate through well-known electro-magnetic relays and switches to the switch voltage taps on the transformer, or to adjust the speed of dr1ving motor 11 by well-known means, as by varying its field strength.

In some cases, I prefer to use a temperature indicating device, which is governed by the resistance of the wire, which ordinarily increases with the temperature. Such device may consist of a voltage regulator, as for instance the well-known Tirel vibrating voltage regulator, ordinarily used to regu-,

late the voltage on electric generator fields. In this case the controlling coil of the Tirel would be connected to bridge a suitable length of the wire being heated near the hottest portion of its length, as for 1nstance by a contact making brush or roller 26 and a connection 27 from lead tank 12, as shown in Fig. 3. These connections supply to the coil or solenoid 28 a voltage that varies as the temperature of the wire is varied, thus causing the plunger 29 to move the rocking beam 30 on its pivot 31 and making contact through 32 or 33 leading through suitable relays to the means for adjusting the field strength of the variable .speed motor to increase or decrease the speed of the wire in transit through the heating circuit, as may be required to maintain the proper temperature.

Heretofore, in tempering wire, which process is sometimes known as patenting, the wire was heated by being drawn through perforations in a heated refractory arch of a long fuel fired furnace, generally 40 feet in length, the purpose of the refractory arch,

through perforations in which the wire is drawn, being to save the wire burning due to the direct contact with the flame. This usually results in a very slow travel of the wire and a protracted period of heating, during which the wire badly scales, generally 4 to 10%.

The wire as it leaves the patenting furnace, through which it has been drawn at an adjustable speed to have it leave the furnace at near the correct temperature, is then generally cooled by contact with the atmosphere or by an air blast, requiring a still further len h of travel, during which the wire is furt er oxidized.

With the old fashioned fuel fired patenting furnaces, oxidation is quite ob ectionable and it is difficult to attain the correct heat in the wire. The tempering effect is never maintained at a maximum, as the wire is quenched (or cooled) too slowly from the upper critical temperature to the lower critical temperature, and is thereafter cooled too rapidly to leave it in the best annealed condition.

My invention provides electric means of continuously heating and quenching the wire and by which the wire may be quite rapidly heated, so as to allow a high speed of transit through the machine and only a short length and period of exposure to oxidation during the heating and quenching processes. As the granular structure of the wire is greatly improved by rapid reduction of temperature between the upper and lower critical temperatures, it is quite desirable that the temperature reduction, whether by means of contact with'cooling rollers, lead bath or otherwise, should be as rapid as possible. It is also equally important, after the lower quenching or critical temperature has been attained, that the wire should be cooled as slowly as possible to eliminate strains and unnecessary hardness, which interferes with the later opera tions in the wire mill.

I have, therefore, arranged to quench or cool the wire by means of the bath 18, maintained at the proper critical temperature, by external means, as for instance, by oil, fire, or other mediums capable of proper temperature control. At other times, I prefer to do the quenching on the flanged contact wheels or rollers 4, cooled merely by contact, the rollers in turn being maintained at proper temperature by oil or water sprays or other well-known means.

The wire having been heated to a temperature above its upper critical temperature, by the time it reaches the first grooved contact wheel or roller of the machine A, is there rapidly chilled by coming into contact with said roller, and still further chilled by passing the successive rollers. When the lead bath is used it is kept at a suitable temperature by electrical or combustion heat or otherwise, for quenching the wire at a tem culture that is somewhat below the critical temperature of the metal being treated. a

The wire enterin the lead bath is immediately quenched from a temperature above its upper critical temperature? to a temperature below its lower critical temper=,

ature. It may then be carried on. through machine A to reel 9 and may be beat insulated while in transit, by such means as asbestos lined chutes, or similar devices, allowing it to further cool at a slow rate. In some cases, machine A may be eliminated entirely and material wound direct onto reel 9, in which case the immediateheat of the wire may be readily conserved; in such cases macline B may be driven at the desired spee The wheels or rollers 4 will ordinarily glive ample contact to the wire, without aux- 1 iary devices, but where desirable to do so, I also add contact brushes 35, see Fig. 2,

made of suitable material, asfor instance,- leaf copper, to reinforce the contact. This,-

under some conditions, is necessar when on account of too rapid chilling of t e wire, it may be essential to use heat insulating rollers, such as asbestos flanged rollers.

Inisome cases where a large quantity of large wire is being fed through the tank,

the heat in the wire being tempered may be more than suflicient to maintain the temperature of the tank, in which case it becomes necessary to cool it by external means,

as for instance, b water spray to keep it at the roper quenc 'ng temperature.

achine's A and B may be set at any suitable distance apart, though generally speaking, I prefer to kee them as close together as possible to avoid lbss of heat and to avoid oxidation. When the machines are spaced far apart I prefer to keep the wire, while being heated, passing through the heat insulating tube 21, havmg asbestos insulation and fitted with a closely fitting seal at each 'end of the tube where the wire enters and leaves, and then I prefer to inject into the tube 21 through the pipe 37, inert or nonoxidizing gases, as for instance producer gas,

or an oilspray, so that the wire is kept prae- 'tically free from oxids until it is quenched consisting in the application of heat insu lating covering, or'non-heat conductive rollers, such as asbestos, or in some cases, it is essential to apply a lower voltage of an electric current between the feed-out device and the take-up reel, as indicated at the left in 'Fig. 3, so as to maintain an annealing temperature on the wire, until it is coiled on the take-up reel, where the mass being coiled generally cools at a slow enough rate, or

lengths are passin from one contact-mak:

in device to the ot er.

y invention is a great improvement over the old method of tempering or patenting wire, due to the much more rapid travel of the wire throu h the machine, the shorter time and lengtfi tion, and the more rapid quenchin and by means of the protecting tube for t e protecting of hot wire by a flow of non-ox1dizing gases it is quite possible to entirely obviate oxid natin the o eration's ordinarily known pick ing, iming and baking.

I do not necessarily limit my claims in this invention to the exact forms of/apparatus shown, for having described my invention, it will be evident to one skilled in the art that numerous variations and deof wire exposed to oxida-- izing the wire surface, thus elimi-' vices may be added by the means described for rawing the strip from the holder, means for passing an electric current through a portion of the stri while in transit, whereby said portion is eated, and means for automatically varying the speed of transit in accordance with the heating requirements.

2. An annealing and tempering device comprising a holder for a metal strip, means for drawing the strip from the holder, means,

for heating the strip while in transit, and automatic means for maintaining the temperature to which the strip is heated substantially constant.

- 3. 'An annealing and tempering device comprising a holder for a metalstnp, means for drawing the strip from the holder, means for assing an electric current through'a portion of the strip while intransit to heat the same, and means controlled by the ourrent flow for automatically ma' taining substantially constant the tempera are to which the strip is heated.

4. An annealing and tempering device comprising a holder for a metal strip, means for drawing the strip from the holder, means for passing an electric current through a portion of the strip while in transit to heat the same, and means controlled by the current flow for automatically governin the speed of transit, so that, when the v0 tage remains the same, the temperature to which the strip is heated is maintained substantially constant.

5. An annealing and tempering device comprising a holder for a metal strip, means for drawing the strip from the holder, means for passing an electric current through a portion of the strip while in transit whereby said portion is heated above the upper critical temperature and means for suddenly cooling the strip to the lower critical temperature.

6. An annealing and tempering device comprising a holder for a metal strip, means for drawing the strip fromthe holder, means for passing an electric current through a portion of the strip while in transit, whereby said portion is heated above the upper cr tical temperature, means for suddenly coollng the strip to the lower critical temperature, and means for thereafter controllin the rate of cooling below such last mentioned temperature.

7. An annealing and tempering device comprising a holder for a metal strip, a pair of strip-gripping and contact-makin machines, each of said machines inclu ing a plurality of grooved wheels or rollers arranged to receive and frictionally grip the strip, means for rotating the rollers of one of said machines at a predetermined adjustable speed, means for rotating the rollers of the other machine at a slightly less speed whereby the strip is placed under tension in passing from one machine to the other, and means for heating the strip during transit between the machines.

8. An annealing and tempering device comprising a strip-holding reel, a pair of strip gripping and contact-makin machines, each of said machines inclu ing a plurality of wheels or rollers arranged to receive and frictionally engagethe strip, said machines being spaced apart, means for rotating the rollers of one of said machines at a predetermined speed, means for rotating the rollers of the other machine at a slightly less speed, whereby the strip is placed under tension in passing from one machine to the other, means for limiting the amount of much tension to protect the strip from breaking, and means for passing an electric current through the portion of the strip between the machines to heat the same.

9. In an electric wire-tempering machine, a wire-holding reel, a wire take-up reel, a pair of wire-gripping and contact-making machines disposed between said reels and spaced apart from one another, each of said machines including a plurality of rollers for frictionally engaging the wire, means for rotating said rollers to cause a forward movement of the wire, a source of current, connections from said source of current to each machine whereby the current is passed through the portion of the wire between the machines, and auxiliary contact-making means in engagement with the wire.

10. An electric wire tempering and annealing device comprising a pair of wire-grip ping and contact-making means spaced apart, means for causing a progressive movement of the wire from one of said pair of means to the other, means for passing a heating current through the strip while in transit and means for independently regulating the speed of transit of the wire and the voltage of the current.

11. An electric wire tempering and annealing device comprising a pair of wire-gripping and contact-making machines spaced apart, means for causing a movement of the wire from one machine to the other, means for passing an electric current through the portion of the wire between said machines to heat it while in transit, and means disposed between the machines for quenching the wire after it passes beyond the heating effect of the current.

12. An electric wire tempering and annealing device comprising a pair of wire-gripping and contact-making machines spaced apart, means for causing a movement of the wire from one machine to the other, means for passing an electric current through the portion of the wire between said machines while in transit, and a liquid bath disposed between the machines for quenching the wire, said bath serving as a contact electrode by which current is conducted through the wire.

13. An electric wire tempering and annealing device comprising a pair of wire-grip ping and contact-making machines spaced apart, means for causing a movement of the wire from one machine to the other, means for passing an electric current through the portion of the wire between said machines while in transit, a liquid bath disposed between the machines for quenching the wire, and means disposed between said bath and one of said machines for preventing the oxidation of the wire.

14. An annealing and tempering machine comprising a feed-in device, a feed-out device, means for causing a movement of the wire to be treated from one device to the other, means for heatin the wire in transit means for quenching t e where the heating means wire at the point ceases to act, and

means for passing an electric current through the wire to again heat the same while in transit after leaving said quenching means.

15. An annealing and tempering machine comprising a feed-in device, a feed-out device, means for causing a movement of the wire to be treated from one device to the other, means for causing an electric current to flow through a portion of the wire in transit between the two devices to heat the same, means for quenching the wire as it passes-beyond the heating efi'ect of such curapart, means for causing a movement of the wire from one machine to the other, means for passing an electric current through the portion of the wire betweensaid machines while in transit to heat-the wire, and means disposed between said machines for quench ing the wire, said quenching means serving as one contact electrode for conducting current through the wire.

17. The herein described method of annealing metal strip which consists in heating it while in transit through a non-oxidizing medium, quenching it to a definite temperature immediately after issuing from such me dium, and thereafter controlling its temperature as required.

18. The herein described method of annealing metal strip which consists in heating it while in transit through a non-oxidizing medium, quenching it to a definite temperature immediately after issuing from such medium, and thereafter again subjecting it to the action of heat.

19. The herein described method of an nealing metal strip which consists in heating it while in transit to a point above its upper critical temperature, suddenly quenching it to a point below its lower critical tempera ture, and thereafter controlling its tempera ture during a definite period by applying or removing heat as required.

WILLIAM E. MOORE.