US1476448A - Apparatus for and method of hardening or tempering wire - Google Patents

Description

- Dec 4 {1923.

c.b. JOHNS ON ET AL APPARATUS; FOR AND METHOD OF HARDENING OR TEMP-BRING WIRE Original Filed Feb, 24, 1920 jams ' O. Jb/vzuoz,

Patented Dec. 4, W3.

entree stares rat an-r oust.

enemas o. JOHNSON AND CHARLES n. :rormson, or woncnisrnnl, MASSACHUSETTS.

APPARATUS FOR Alhfi) METHOD OF EARDENING 0R TEMPERIITG" Application filed February 24, 1920, Serial No. 360,879. Renewed October 20, 1928. v

To all whom it may concern:

Be it known that we, CHARLES O. J OHNSONQ and CHARLES D. JOHNSON, citizens of the United States, both residing at'lvorcester, in the county of WorcesterandState' of Massachusetts, have invented a new and useful Apparatus for and Method of Hardenin g or Tempering Wire, of which the following is aspecification.

p This invention relates to the bright hardening or bright tempering of wire, and particularly to that method-according to which the wire is drawn first through a lead bath and then through an oil bath.

Although not particularly-limited thereto this invention may be considered as an improvement over the invention of the said Charles'(). Johnson set forth in his application for patent on apparatus for hardening and tempering wire, Ser. No. 291,322, filed April 19, 1919, and we have shown it herein as being applied to that apparatus and the method disclosed in that application.

The principal object of this invention is to provide for reducing the temperature of the lead bath through which the wire passes between the time at which it is Sub ected to the highest temperature and the time at which it is introduced into-the oil so as to reduce any tendency of the lead to stick to the wire and be drawn out of the lead bath with it. i

The invention involves in its preferred form the provision of one or more baths or compartments of .molten lead, preferably located outside the ordinary furnace which is usually employed in hardening wire, the temperature of the said additional bath or baths being regulated so as to reduce it finally substantially to the temperature at which lead melts, so that the wire will. be drawn out of the lead into the oil bath at the lowest temperature possible.

Reference is to be had to the accompanyin drawings, in which %'ig. 1 is a plan of a hardening and tempering apparatus constructed in accordance I with this invention;

Fig. 2 is a longitudinal sectional view of the same, the invention being shown, as Stated above, as used in connection with the mechanism set forth'in the above mentioned application, and

Fig. 3 is an enlarged longitudinal sectional view'of the hardening apparatus.

As iswell understood in this art, a plukettle 10.

rality of wires are led through the lead kettle or bath 10' of a hardeningtfurnace 9 where the wire is subjected to the highest degree of heat necessary to accomplish the well known result. Y

According to this invention the lead kettle or bath 1O occupies the usual position in the furnace 9 and is of alength substantiall the same as the length of the furnace. W2 have shown this as being supplemented by two additional lead baths or compartments 12 and 13. These are heated in any desired way, as for example, by gas or oil burners 14 and 15 which can be regulated-to any desired degree. It is important that the bath or kettle 13 should be heated only just a little above the. melting temperature oflead so as just to keep the lead in a molten condition and not superheat it above that state, while the bath 12 'is kept at a. temperature intermediate between that and the' temperature of the bath-1O in the furnace. This is controlled by the regulation of the burners 14c and '15.

Although we have described these three baths as separate we prefer to form them from a single castin in the form of a pan or kettle 16 which iS- ivided by partitions, as

forexample,' 17, 18 and-19 to provide the several compartments. We have also shownthe kettle or compartment 12- as' comparatively narrow, the kettle or compartment 13 beingabout 50% wider thanthe narrow kettle12. The latter is shown as approximately a quarter of the length of'the main These partitions are provided with grooves 20 in their upper surfaces for allowing the wire to pass from one to the other in a straight line always underthe surface of the metal so that they have no access to the air.

At the point where the steel wire passesv from the bath 13 to the cold oil bath" 21 the wire is protected also from contact with the open air. The bath '13 is kept substantially at the melting point of lead and for that reason as the wire passes from the lead to the oil the carbonization of the oil by the heated Wire, so common in this art, and also the lead pulling, does not take place and the smoke and fumes ordinarily encountered are substantially eliminated. The last, wall 19 is provided with Slots 22 through its upper surface which extend down to. a level below the normal level of the molten lead in that compartment. The grooves or slots I 22 are of a size adapted .to the size of the wire and they allow the molten lead to stand in them as the wire passes through. The

molten lead does. not wet or stick to the walls of the grooves and the low temperature to which it is brought assists in preventing this. It does not run out through the grooves because of the natural repulsion between the surfaces of the iron walls of the kettle 'are'near the surface of the lead bath. Fur-- and the molten lead and because the grooves thermore the oil at a lower temperature meets the lead in the grooves andrepels it;

As will lee-seen it also flows over a grooved dam 23 in a direction to force back any lead in a free condition located in these grooves.

Although we mention lead and oil the invention is applicable to any] other suitable heating'and cooling liquids.

,A space 25 is provided between this dam i and the wallcl9 for receiving the oil asit flows over the dam and waste pipes '26 are 'provided for introducing the oil therefrom into an oil tank27 below, said pipes extend below the level of the oil in said tank so as to exclude. air from entering said pipes.

'The oil in the tank 21 is kept at such a level by any desired feeding apparatus and an overflow 29 as to cause it to constantly flow over the dam. This dam is provided with slots 28 in its upper edge or apex for receiving the wires directly from the slots 22 in a straight course. This is to cause the wire to pass through in a straight line without exposure to the air, being covered by the lead until the instant at which itenters the oil. The dam is adjustable and held in position by means of screws 3O.

It will be noticed also that on account of the flow of the oil in a direction the reverse 4 of that ofthe motion of the wires there is a tendency to prevent its temperature from being raisedexcessively by the wire.

The above description is of'the hardening apparatus, but the tempering apparatus 39 is constructed in substantially thesame way except that the tempering lead bath 40 is not necessarily located in a covered'furnace because the temperature of the lead bath is lower, but additional lead baths ell and 42 are employed and heated to a still lower temperature by gas jets 43 below or in any other desired'way. 1

I In this way not only is the wire prevented from being exposed to the air during the hardening process and also during the tempering process, but it is introduced into the oil at a reduced temperature, thus preventing the lead from sticking to the wire and being carried over into the oil, producing combustion of the oil by its contact with the heated wire. The uniformity, strength and temper of the wire are all improved.

Although we have illustrated and deadvance do not wish to be limited to all the details a of construction or to the specific type of hardening and tempering apparatus herein shown and described, but what we ,do claims is 1.' In an apparatus fortreating wire, the combination with a lead heating bath and an oil cooling bath, of an intermediate lead bath between them kept at a temperature,

below the-temperature of the first named lead bath and means for guiding the wire through said baths in a substantially straight line below the surface of the lead in each lead bath.

2. in an apparatus for treating wire, the

combination with a heating'bath and a cooling bath, of an intermediate bath between them kept at a temperature below the temperature of the first named bath, and a. partition between the heating and intermediate,

baths having a passage for the 'wire located below the level of the. liquids therein.

3. In an apparatus for hardening or ternpering wire, the combination w th a molten lead heating bath, a bath of molten lead maintained substantially at the melting point of lead, a lead bath between them kept at an intermediate temperature and a cooling bath. i

4. In an apparatus for hardening or tempering wire, the combination with a molten lead heating bath, a bath maintained substantially at the melting point of lead, a bath between them kept at an intermediate temperature, a cooling bath of oil, and

means for guiding the wire through said baths and for keeping it out of contact with air as it passes from one to the other.

5. In an apparatus for hardening and tempering wire, the combination of a comparatively long molten lead heating bath, a bath of molten lead maintained substantially at the melting point of lead, and substantially shorter than the heating bath, and an intermediate bath shorter than either.

6. The method of bright hardening or bright tempering ofwire, which consists in passing the wire from a lead bath maintained at the usual hardening or tempering temperature into a second lead bath maintained at a lower temperature, then into a thirl lead bath barely maintained at the melting temperature of lead, and then di rectly into an oil bath and keeping the wire immersed in each bath until it enters the next one to prevent contact with air.

7. The method of hardening or temper ing steel wire which consists in immersing it in a bath of molten metal, then reducing its temperature while still submerged in molten metal and without changing its direction of motion and finally passing it through a cooling bath. a

8. The method of bright hardening and bright tempering of wire which consists in passing the wire through a plurality of connected baths of molten metal of varying temperature directly into a connected oil bath and keeping the wire immersed in each bath until it enters the next one to prevent contact with the air.

9. In an apparatus for hardening and tempering of wire, or either, the combination of a plurality of molten metal baths of varying degrees of heat, with' an oil bath directly connected therewith and means for keeping the wire submerged in each bath until it enters the next.

In testimony whereof we have affixed our signatures.

CHARLES O. JOHNSON. CHARLES D. JOHNSON;

hereunto

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