US2283798A - Apparatus for annealing wire - Google Patents

Description

May 19,1942. J. K. DELANO I APPARAIUS FOR ANNEALING WIRE Filed March 10, 1959 Enoentor O N A L F- JAMES K.

Gttomeg cles from the wire.

Patented May 19, 1942 UNITED STATES PATENT. orr cs r amass APPARATUS FOR ANNEALING WIRE James K. Delano, Poughkeepsie, N. Y., asslgnor to Delano Patents Company, Dover, DeL, a colporatlon of Delaware Application March 10, 1939, Serial No. 261,132

1 Claim.

ing machines, to allow the wire to be drawn and annealed so it can be wound directly upon the spools so as to do away with the extra handling of the wire as practiced in the trade today.

When the annealing of the wire takes place in the open air, the temperature to'which the wire is subjected is extremely critical, and if raised too high, a film of oxide forms giving the wire a false surface, upon which the insulating material will be coated. with the insulating ma terial adhering to this false surface, when the wire is stretched or twisted, a cracking or flaking of the false surface will take place, resulting in the breaking of the insulation at these places. When copper wire is drawn to smaller sizes from the original rod, the number of times required to reduce its diameter before final size is reached causes the surface of the wire to appear in places, when viewed under a microscope, to resemble a tree with the bark liaising cit. This is due to the surface being hardened by pass ing through the dies while the center or core of the wire remains ,soft, causing the hardened portion to have stresses which cause it to peel away from the parent core.

These flakes, splinters, or projections are extremely minute but are a source of trouble in producing a good dielectric coating as they irequently project from the wire, and when the coating is dry, the flakes or splinters will be protruding through the insulation, thus producing a puncture in the film of insulation.

It is the usual practice to endeavor to clean the wire before insulating by passing the wire through dry sand or felt to scrape these parti- Unless the felt or sand is being continually renewed, the accumulated cop per dust will aggravate instead of remedying the condition.

Another source of poor insulation is caused by the lubricating greases or soaps used in the drawing dies. These cling to the wire and carbonize' during the annealing and aflord poor adhesion and bad dielectric.

An object of my invention is to cause any oxides or tarnish, on the surface of the wire being annealed, to be reduced so the surface of the wire is clean and bright; and foreign matter being thrown off the WM: due to its flexing and speed of travel through the annealing process.

Another object of my invention is to provide an apparatus forpreventing the forming of oxides during the annealing process.

Another object of my invention is to provide an apparatus for annealing, whereby the wire be- I ing annealed is kept in rapid motion and surrounded by an atmosphere of inert or reducing gas while it is being heated, to prevent oxidation.

With these and other objects in view, my invention consists in certain novel construction and combination of parts as will hereinafter be fully described and claimed and further illustrated in the accompanying drawing which forms a part hereof, and in which like figures of reference refer to corresponding parts in all of the views, and it is understood that slight changes may be made without departing from the spirit of the invention. 1

In the drawing:

Figure 1 is a schematic view of the apparatus for generating the inert or reducing gas, and the housing for annealing the wire.

Figure '2 is a sectional side view of the annealing housing.

Referring to the drawing:

It is understood that the device is to be mounted in or adjacent a suitable wire machine having means for imparting movement or travel to the wire to carry it through the device, and as the construction and operation of such machines is well known in the art, it is unnecessary herein to describe the means for imparting movement or travel to the wire. I

The device comprises a burner I0 with means for connecting it to a gas supply H, such as city gas" with a valve l2 for controlling its flow and a valve 63 to control theair required to produce an air deficient flame. To retain this generated gas or the products of combustion and prevent the addition of any outside air, the burner 'Is is enclosed in a housing l4 provided with a weighted air-tight door l5 and a pipe ii for taking away the inert gas thus generated. The door I! provides an opening through which the burner l0 may be ignited, and also acts as a safety valve to relieve any inside pressure due to any undue'expansion of the gas and air.

A standard thermostat 25 is also enclosed in the housing l4 and connected by a magnetic solenoid'or other suitable device to close the gas valveiitheflameshouldbeextinguished. This isnotshownasitiscommonintheart.

From the housing II, the gas is-carried by-the pipe." to a water cooled condenser-i1 where the inertgasiscooledbythewatertubes lltcremove the water vapor oi combustion from the gas. This water vapor is condensed on the tubes II and settles to the bottom or the condenser II where it is carried on by the pipe It to the water trap II to prevent any gas from escaping or air from entering the condenser ii.

For any' soot or combustion products which is being carried by the inert or burnt gas will be deposited upon the tubes ll so I have provided a sprinkler pipe II in the top of the condenser l1 bywhich the tubes ll may be washed to remove any residue which may cling thereon and also may be used if desired to wash the inert gas, although the scrubbing or cleaning oi the gas can be done in a separate compartment. To prevent this washing water or the condensed water ing valve ll.

From the outlet of the blower it and by the 'throughthehousingllareelectricallyeonneeted byflatspringslltothebackotthehwllngillr By extending one 01' the'shaitsl! the sheave wheelsllandumaybedrivenbysomesuitabie' source of power. I

Anarrowslotllinthebaseotthehmrsinglt hasbeenprovidedtoallowthewirelltoenter from the sp ol l1 and a similar narrow slot 1' provided in the top to allow the wire II to leave to the spool II.

Above the housing 28 is placed a hood or flue II for connection to a suitable chimney for catching and removing any gas escaping from the slot II to prevent the entrance of any gas into the surrounding room. The slight gas pressure in the housing will prevent any air from entering by the slots I4 and Ii.

A weighted'air-tight door I secured upon the side or the housing It provides a safety valve by which any undue pressure will escape it a combustion should take place within the housing.

In the operation of the device; I take ordinary "city gas, although it is possible to burn charcoal, coal, petroleum or its various distillations,

pipes 20 and 21 the generated gas is delivered to the annealing devices 28, of which only one is shown, through the control valves 29 and wire gauze ll preventing any possible explosion in the annealing device 28 from flashing back into the supply line.

The annealing device 2. comprises a rectangular box of cast iron, or other suitable material, equipped with a door 2! swung upon the hinges 30, so as to permit the door 2' to be closed and tightly held in place by the catches ll thus providing an air-tight door.

Qentrally located in the back of the housing II and adjacent each end are two holes ll through which the insulating bushings 41 extend. Through these bushings 41 are inserted metal tubes ll formed with a flange II on their outer roller bearing ll, a spacer II, and another rollerbearing 42; the whole assembly held against the shoulder ll by the lock nut 43.

On the opposite ends or the shafts I! are secured the two sets of sheave wheels 83 and 34. The outer set I! having the wire to be annealed strung around them; and the inner set 34 connected by a drive belt composed of insulating material such as canvas, cloth, leather, rubber or some other suitable material. when the wire I is pulled from the upper sheave wheel 38, the lower sheave wheel will be turned by the insulatingbeltsoastotakeanystrainorpullirom and burn it under similar conditions in a tightly enclosed chamber, as chamber ll, resulting in an inert reducing gas. This gas is ,drawn by the .blower It through a water cooled condenser II blower 24 and piping II and," is now supplied to the annealing devices II through the valves 29 and mesh screen 3..

The secondary of a transio er II, whose primary is connected to a source of power. is connected to the screws II in such a manner that i when the current is turned on and the wire It is around the sheaves I, a closed'circuit will be made through the wire I! which will result in the temperature of the wire I being raised to any temperature desired in proportion to the amount or current delivered. So by a suitable rheostat, not shown, for raising-or lowering the current 01' the transformer, the temperature 0! the wire "will also be raised or lowered.

The wire will then be raised toannealing temperature in the presence or the inert gases andas soon as it leaves-the electrical current between the two sheave wheels I! and 84 the wire will commence to cool, and the housing Il may be extended, if required, to allow the cooling or the wire it in the presence of the inert .75 evenred heat.

Copper wire that is black from age, or badly tarnished. will, when run through this device be Just as clean and bright again as though it were Just newly drawn or bright acid dipped.

The heating or the oxidized wire in the reduc-' appear to be re-fused into the base metal as through the copper has been remelted, which-ls not possible as the annealing temperature is not The travel of the wire at high speed around the pulleys 33 and of the annealing device,

and the expansion and contraction of the wire under heating and cooling, causes any carbonized soap or inert matter to leave the surface of the wire and accumulate at the bottom of the enclosing box 28 where it can be periodicallycleaned out; instead of being carbonized on the wire and unable to leave it, which would be the case if the wire were spooled and then annealed.

The products of the burner flame have been referred to as an inert or reducing gas in the specification; no doubt the gas is composed of a combination of combustion gases such as C0, C02, and H, and also other products of incomplete combustion. The important part in producing the best results appears to have enough flame to cover the air inlet at the point of combustlon so all the air must pass through the fiame,'and that just enough air be admitted to support combustion so that it burns with a dark center and yellow edges.

7 The relief doors l and 8. inthe burner housing, I4 and annealing box 28 are provided, in case the raw gas should get into the system and be ignited. This condition might arise should the flame become extinguished.

With the above process the wire is dead soft annealed without oxides. Any oxides formed previously or during annealing are reduced and all foreign matter adhering to the wire is removed.

By the employment of the insulated belt, the wire is not stretched, thus resulting in a perfectly clean, bright, annealed wire ready for enameling and requiring no further scouring or cleaning.

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

Apparatus for annealing fine wire subject to stretching comprising a driving pulley and a driven pulley, said pulleys being mounted in spaced relation in a housing and electrically insulated therefrom for rotation with a drivin shaft and a driven shaft, respectively, said pulleys being adapted to carry and continuously advance a continuous (strand of wire which during operation of the apparatus is continuously supplied to the driven pulley and continuously withdrawn from the driving pulley and makes at least one complete pass around each pulley; means to apply electrical heating current to the wire between the pulleys; and mechanical means connecting thedriving shaft with the driven shaft and electrically insulated from said shafts to rotate the driven shaft from the driving shaft and at the same speed as the driving shaft; whereby the increments of wire which during operation of the apparatus are advanced in a heated condition from the driven'pulleyto' the driv ing pulley are substantially relieved otitension.

JAMES it. DELANO.

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