US2426718A

US2426718A - Heat-treating apparatus

Info

Publication number: US2426718A
Application number: US586191A
Authority: US
Inventors: Otto J Vanek
Original assignee: American Steel and Wire Company of New Jersey
Current assignee: American Steel and Wire Company of New Jersey
Priority date: 1945-04-02
Filing date: 1945-04-02
Publication date: 1947-09-02
Anticipated expiration: 1964-09-02

Description

Sept. 2, 1947.

o. J. VANI-:K

HEAT TREATING APPARATUS imed April 2. 1945 4 sheets-sheet 1 Y |NvEN`ToR Orro d l/ANEK,

. J. VANEK i HEAT TREATING APPARATUS Sept. 2, 1947.

Sheets- Sheet .2.-

Filed April 2, i945 mvENToR i Orro J 14a/Vex,

Sept. 2, 1947.

o. J. VANEK HEAT TREATING APPARATUS Filed April 21945 4 sheets-sheet 4 Patented sept. 2, 1341 Otto J. Vanek,

Cleveland, Ohio, assignor to The American Steel and Wire Company of New Jersey, a corporation of New Jersey Application April 2, 1945, Serial No. 586,191

Claims.

This invention relates to improved heat treating apparatus of the type wherein metal articles are heated and quenched.

The invention has among its objects the provision of heat treating apparatus wherein a batch of metal articles is so treated that the structure thereof is uniform both throughout each article and from article to article. y

A further object of the invention is the provision of such apparatus in which the time from the cessation of the heating operation to the delivery of the articles into the quenching bath is markedly reduced.

A still further object of the invention is the provision of heat treating apparatus wherein the transfer of the heated articles from the heating zone to the quenching zone is rapidly and easily accomplished.

These and other objects of invention will be more apparent inthe followingdescription.

In the heat treating of articles, particularly batches of elongated articles such as bars and the like, where such treatment involves the heating and subsequent quenching of a plurality of articles'at one time, it has been customary to heat such articles in either a box type or a care bottom furnace with the article supported on a rack, to remove the box type furnace cover or to run the car out of ,the furnace, and then to pick up the rack with the articles thereon as by a crane and either to lower the rack with the stock thereon into the quenching bath or to tip the rack so as to c ause the articles to fall there'- from into the quenching bath. The time required to accomplish such manipulation of the stock support, after removal of the furnace therefrom or its removal from the furnace, allows the heated articles to cool materially before quenching, particularly on their outer surfaces, so that the resultant heat treated articles frequently do not have the desired structure or hardness. Furthermore, because of the non-uniformity of such cooling throughout the batch, the

,heat treated articles vary considerably from article to article; a great many of them treated in such manner have to be scrapped or at least recharged again into the furnace for reheating and requenching, thereby causing a material increase in cost `for the particular heat treating operation involved.

The apparatus of the presentinvention overcomes the difficulties, outlined above, attendant upon the use of prior art apparatus, by providing' a stock or article support which may be tilted immediately after removal of the furnace therefrom or removal of the stock support from thev furnace.

Tilting of the stock support, which may, when a box type furnace is employed, be accomplished as an incident to the lifting of such furnace, a1- lows the articles to be discharged by gravity and tol fall into anvappropriate quenching tank. The apparatus of the present invention also provides novel skidsV or guides between the stock support or rack and the quenching tank to guide the heated articles discharged from the support into the quenching tank.

The invention will be more readily understood by reference to the accompanying drawings, in which:

Figure 1 is a view ,in vertical section through heat treating apparatus of one modication of the invention in which a box type furnace is employed;

Figure 2..is a view in vertical cross section of the apparatus shown in Figure 1 with the furnace cover lifted from the article supporting rack;

Figure' 3 is a view in cross section showing details of the stock supporting rackand the cooperating skid members, said section being taken on line III- III in Figure 2;

Figure 4 is a view in plan of another modifica-v tion of the heat treating apparatus ofthe present invention, in which a car-bottom type furnace is employed; and

Figure 5 is an end view of the apparatus shown in Figure 4.

In the modification of the apparatus shown in Figures 1, 2, and 3, the elongated box type furnace 2, which may be of a type similar to that n shown in the patent to Woodson, No. 2,068,477,

is adapted to be lifted by means of a crane to allow the charging of the material thereinto and the discharge of the heated material therefrom. Furnace 2 when in operative position, as shown in Figure 1, rests upon a furnace base 4, which in this instance, is positioned between and equidistant from two quenching tanks 6 and 8, which are made of a suitable length to receive the articles being treated; Tank B may, for instance,

contain a bath of oil which may be used in the Y heat treatment of one particular type of: steel, whereas tank 8 may contain water which may be used in the heat treatment of different types of steel or in a different type of heat treatment of the same kind of steel. In Figures 1, 2, and 3 the articles to be heat treated are shown as receiving an oil quenching; consequently, tank 8 is not used in su'ch method and is shown with its cover down.

Positioned on top of furnace base 4 are a' plurality of rack supporting members i which may be, for instance, in the form of hollow U-shaped beams extending in the direction at right angles to the paper for the length of the stock supporting rackl2,on.'.top 'of which is positioned,

being provided on the top thereof with an ar-v ticle supporting plate I8 welded to the frame.

To allow the tilting of the stock supporting rack in the direction of the quenching tank which perature, the furnace heating means' is shuty off v is to be used, said rack is provided at one bottom edge thereof with Ja longitudinal pivot bar 20 -which seats-in one set of a plurality of yokes 22,'situated on the `edge of the support-I0. When but one quenching tank isA employed, it is obviouslynecessary to vprovide onlyone set of yokesv 22 ,on the edge of support I0 adjacentthe tank.`

In' the modification shown in Figures 1 and 2, however, yokes 22 are shown provided on both edgesof'support I0 so that the rack may be reversed in position merely by'being picked up by a crane and turned around, and thus may be l made to cooperate with either quenching tank.

Positioned on the upper edge of the rack- I2, at a position opposite the pivot bar, is a rack lifting bar 24 by which the rack may be tilted, in a manner subsequently described; another longitudinally extending bar 26 is provided on the edge of the rack at a position somewhat below the top I8 of the rack and on the same side thereof of the pivot bar 20. Bar 26 is provided for the support of the article guiding skids 36 over which the articles travel into the quenching tank. The bottom outer edge, of thebox typefurnace 2 on the side oppositeV the quenching tank being used is provided as shown with a hook 28 which may be attached thereto as by a short chain. Hook 28 is provided with a long handle 30 so that the hook may be manipulated ata distance so as to be engaged with lifting bar 2'4 when the furnace is raised.

The quenching tank '6 is provided with a cover 32 connected thereto by a hinge -34 on the edge thereof adjacent the furnace so that the cover may be swung into a position inclined toward the furnace as shown in Figure l. The outer end of the cover is provided with a plurality of skids or arms 36 hinged thereto at 38 so that the arms may be swung outwardly into a plane coextensive with the cover. 'Ihe arms may be held in such coextensive position by means of base for the discharge of the articles.

4. The furnace is then lowered into operative position on the base and is operated to bring the charge to the desired temperature. The cover 3.2 of the quenching tank 6, with the arms 36 held in rigid extended position thereon, is then tilted s o thatthe outerendsof the arms contact the sidefof the furnace as shown' in Figure l.r When the articles have been heated to the desired temand the furnace is hoisted, as by means of the crane hook- 44, to raise it clear of the furnace During such hoisting, the furnaceis caused to travel somewhat to the left 'of the furnace base as shown in Figure yl to bring hook 28 into such position relative to lifting bar 24 that it may engage the bar when manipulated byhandle 30. At such time, the furnace will have been lifted suiiciently to allow the outer ends of the arms 36 to clear the bottom* edge of the furnace and thus to allowthe cover 32 and the arms 36 as a whole todrop until the arms rest upon bar 26. In such' position the top surfaces of the arms 36 lie slightly beneat'hthe top surface of the'article supporting plate I8 of the rack so that upon further lifting of the furnace and consequent tilting of the` rack, the heated articles roll or slide oif the rack onto the arms thenceto the cover of the tank and into the tank. The tilting of the article supporting rack and the discharge of the articles thereon in a manner described may be accomplished 'in a very short time, so short in factthat little or no cooling of the articles takes place before they drop into the quenching bath. Consequently, the articles may be heated to the optimum temperature, and uniformity heat treatmentin the individual articles throughout their extent as well as uniformity from article to article in the will be insured.

Although the modification of the apparatus of the present invention shown in Figures 1, 2, and 3 displays perhaps the most advantages as far as speed `and simplicity of operation are concerned, the apparatus is also capable of use and displays advantages in connection with heating furnaces other than those of the box type. One such other type of furnace is that shown in the modification illustratedin Figures 4 and 5. Inthis modification the tilting stock supporting rack and the cooperating quenching tank having a pivoted cover and extension arms or skids are employed with a furnace of the car-bottom type. Such furnace, which is shown at 46 is provided with a U-bolts 40 embracing the arms and extending..

through the outer edge of the cover.

The other quenching tank 8Which is shown in Figures 1 and 2,4is likewise provided with a cover 32 hinged thereto at 34', said cover having skids or arms 36' pivoted thereto. When either quenching tank is not being used, the'U- bolts 40 are removed so as to'allow the skids or arms to hang freely from the cover, as shown in connection with quenching tankv 6,"w`henI the v cover is positioned over the tank.

The apparatus shown in Figures' 1, 2,"and313 Y. may be employed in the heat treatment of al batch `of articles, for instance, a plurality of elongated `The quenching tank 54, which is of the length the bottom edge thereof adjacent' tank SIfWitl-fa bars, in the following manner.` The stock *suQp-Eg: porting rack I2, in a horizontal position as'shwn in Figure 1, receives the charge of articles thereon with the furnace 2 hoisted from furnace base rsufficient to accommodate lthe articles being,

treated is similar to the ytanks 6 and 8l inA the first modification above described. Tank 54. is provided with a hinged cover 53, said coverhaving VVa plurality of extension or skid forming arms 58 pivoted and secured thereto in the same'-manner as in thelilrst modication. The charge supporting rack' 60, which isfsupprted on supporting member 62 on top of the car 50,-is providediialt longitudinal pivot bar 66'resting in a pluralit'y of yoke members 64. Rack'60" is likewisenprotided with a longitudinally extending bar 68 for supporting -the outer ends of arms 58, and with a batch rack lifting bar 10 on the side thereof opposite the pivot bar 65.

In the apparatus shown in Figures 4 and 5, the articles to be heat treated, which may be a plu.- rality of bars 6 I', are loaded upon the rack 60 with the car in its outer position, and the car is then run into the furnace where it remains until the charge has reached the desired temperature. Thereupon the car is retracted from the furnace and the cover 56 of the quenching tank with the arms 58 in. extended position is then swung to a position so as the arms rest upon skid supporting har 68. Lifting bar 10 is then engaged with a suitable lifting means, and the supporting rack is then tilted into a position such that the charge of bars rolls down the racks onto the skid arms 50, to cover 56, and into the quenching tank. The lifting means for accomplishing tilting of the rack is shown 'in Figure 5 as consisting of a hook 12 attached to a crane cable 16, said hook having a long handle M affixed thereto to'allow an operator to .engage the hook with .lifting bar lll..at.a distance. Such operations may easily and rapidly be carried out so that only a very small time elapses from the withdrawal of the charge from the furnace until' it has been discharged into the quenching tank. Consequently, this modification of the apparatus as well as the rst allows the production of heat treated articles which are characterized by their uniformity of heat treatment throughout their extent as well as uniformity of structure from article to article in the batch.

Although I have described and illustrated herein preferred forms of construction of the heat treating apparatus of my, invention, it will be i obvious that-,changes in the constructions shown may be made without departing from the spirit of the invention or the scope of the appended claims.

I claim:

l. Apparatus for heat treating a batch of elongated metal articles comprising a furnace to receive such articles, an elongated article holding rack supported normally inv horizontal position in the furnace, the support for the rack comprising a horizontal pivot parallel to the length of the rack about which the rack may be tilted to discharge heated articles sidewise therefrom, means to tilt the rack, a quenching tank located adiacent the furnace with its `dimension parallel to the length of the rack great enough to receive the elongated articles, and movable skid means which may be selectively interposed between the tank and therack to convey the heated articles from the rack, when the latter is tilted, into the 2. Apparatus for heat treating a batch of elongated metal articles as defined in claim 1, in which the skid means comprises a cover for the quenching tank. said cover being hinged to the tioning as an on, said cover being hinged to the upper edge of the quenching tank adjacent the furnace, said cover being swung on its hinge to lie in a direction toward therack when functioning as an article conveying skid, the extension arms on the cover being supported at their outer ends by the skid rest on thev rack when veying position.

4. Apparatus for heat treating a batch of elongated metal articles comprising a box type furv nace adapted to be raised to allow the charging v from it, an

of material-into. it andthe discharge elongated article holding rack normally supported in the furnace in horizontal position, the support for the rack comprising a horizontal pivot parallel to the length of the rack about which the rack may be tilted to rdischarge heated articles sidewise therefrom, means to raise the furnace clear of the rack, and means connected to the furnace to tilt the rack as the fur nace is raised, A

5. Apparatus for. heat treating a batch of elongated metal articles comprising a box type furnace adapted to be raised to allow the charging of material into it and the discharge of material from it, an elongated article holding rackl normally supported in the furnace in horizontal position, the support for the rack comprising a horizontal pivot parallel to the length of the rack about which the rack may be titlted to discharge heated articles sidewise therefrom, said pivot being located in the vicinity of one lower longitudinal edge of the rack, means to raise the furnace clear of the rack, and means connected to the furnace which may be connected to the rack on the side thereof opposite the pivot for tilting the rack as the furnace is raised.

OITO J. VANEK.

REFERENCES CITED The following references are of record in the file of this patent: l

UNITED STATES PATENTS Number Name Date 1,638,908 Baker Aug. 16, 192'? 1,638,937 Keene Aug. 16, y19..'2'7 2,366,088 Goody. Dec. 26, 1944 1,343,019 Wikstrom June 8, v1920 the skid is in article conof material