USRE13050E - Process of joining metal pieces - Google Patents

Description

H. GOLDSGHMIDT.

PROCESS 0F JolNING METAL PIECES.

APPLICATION FILED MAY' 7. 1906.

Reissued Dec. 7, 1909.

2 SHEETS-SHEET 1.r

H. GULDSCHMIDT.

PROCESS 0F JOINING METAL PIECES. I APPLICATION FILED MAY '1, 1906.

13,050. z SHEETS-SHEET 2.

Reissued Dec. 7, 1909.

UNITED STATES PATENT OFFICE.

HANS GoLnscHMInT, oF-EssEN-oN-Tnnnniin, GERMANY, AssrGNoR, BY DIRECT AND MESNE ASSIGNMENTS, To croLDscHMIDr'.` THERMIT co., oF NEW2 YORK, N. Y., n

CORPORATION or NEW PROCESS or JoININGr'iinamiLA PIECES.

A Specificationv of Reissued Letters Patent.V Reissued Dec, ,7, 1909,

- n original No. 717,840, dated January c, 190:5, serial 110.65492. Application fbr reissue mea may 7, 190e.v

' 'serial No. 315,686. l

Tio allvwhom t .concem:. l l

Be i known that I, HANS GQLDSCHMIDT,a subject o f -the King of Prussia.,l German Emeror, and a resident of Essen-onthe-Ruhr,

`ermany, have invented a new and -Improved Process of Joining 'Metal Pieces, of

j which the following is an exact Specification.

` aid of the heat producedfby lthe chemical reaction between aluminium and oxids of metals or other oxygen-containing metal compounds (especially oxid of iron) the reaction inassis used only as calorifying agent 'and the metal produced by the reaction .ser-ves only-as a heat-conductor. 1 -Therefore in these alumino-thermo processes care was I' taken thatthe molten-alumina-slag at first .carne in co'r'itact with the ieces to be welded and only. after the same j ad formed a' protecting-'coating around the pieces the molten metal was iowed around the welding-pieces.

Inmost cases these-itwostepsof the process f e'r'e carried out by merely` pouring the mass 'ulting from theA reaction out -of the' cruy 'cible 01 melting-pot, .whereupon the alumina floating'on to would of lcourse flow out first, and the'. eavier molten metal would flow out afterward. Thus direct contact of` the molten metal with the metal pieces to be Welded was avoided,v as was union of the molten metal with such metal pieces.

By my new process it is attained that'the molten metalcomes directly in contact with the welding-pieces, so that the metal may partly join with the pieces, thereby strength.. ening the joints, whereafter the whole reacf tion mass begins its operation as 'caloriying agent for the welding process.

The process shall be described, for. ex-

ainlple, as used for j oin'ingJ rails or the like. he joining faces of the rails areat. rst

surrounded with a suitable mold n1anufac' tured ofsheet-iron, clay, or the like, after which a Crucible provided -with a tap-hole is placed over this mold in such a way that the stream of the molten mass vflowing out of this hole does not directly fio'w' upon the 1ails,'b`1"1t Hows into the space between the: .1

rails and the wall\of .the mold. Then this Crucible after .closingrtle tap-hole is.. filled mixture of aluminiumand oXid of iron-l- -same may effect the welding of thc joining faces; secondly,. the heating of the upper part of the rails prevents the bending .up of' the rails near the joining faces, which bendsimilar processes by holding the joining faces down by means of clamps and the like.

The tap-hole of the Crucible may be closed byA means of aclay plug or the like, or the hole `may be covered -with a metal sheet,

crucible with the mixture. Inthis case the to the bottom of the Crucible will melt this covering, whereby the tap -hole will be opened automatically,

an example described in connection with the characters denote-similar parts, and in which the two rails to be,- joined andthe mold. Fig. 2 is a side'view of the rails. Fig.I 3 is a perspective viewof the joint. '.Figs. 4, 5', 6, 7, 8, 9, and 10 are modified forms of aretfect. Y v j In Figsiland 2, a a are the rails to be joined. 'bj' Z7 are sheet-iron molds, the upper one of which consists of two parts sur- The side walls c c of these molds `may advantageously be formed of sand or wet clay. By the special construction of the molds three hollow spaces f are formed, in

which theinolten massis cast.

joined. First, the heating attained by the (Sheet-imm) or the like before filling the In order to make my invention more clear, I will proceed tof illustrate the process by accompanying` drawings, in which similarA A Figure 1 showsya section through oneoii rangements or carrying the process into .with the`reaction`mixturefor instance, a i

55.. I after which'the reactionisintroduced. Once..

ing up it has been yattempted to avoid in molten iron as soon as the reaction has come rounding the rails near the joining faces. l

' quantity ofthe mixture, then to ignite the The process is carried out inthe following' manner: The metal piecesl are pressed Then a crucible is filled with a mixture of aluminium and oxid of iron, both in pulverized fornnwhereafter the mixture is ivnited. It is advantageousv to fill the crucible beforehand with a small same and gradually add further quantities. When the whole mass isV in reaction, the molten alumina floating above the iron is cast into the form f. This alumina-slag congea-ls at once vupon the cold surfaces of the i rails'andf the bottom as well as the side walls of the mold 'andv forms coatings d' z', which protect the top part of the railsA against getting deformed. The. otherfpart ofjthe alumina-slag between the coatings is still liquid,l but congeals lafterward'. Then-'the iron cast into the mold b after a hole o has been punched through the bottom of the mold b' and t-he alumina'coating t'. Evidently the bottom of the mold b' will not oifer great resistance to punching the hole through, since the metal has been heated byv the alumina. v

As already mentioned, the alumina heats the tWo parts to be welded together, while theiron forms a fish-rail around the bottom partsof the two rails in order to strengthen the joint." The two rails are pressed together'after the molten mass has been cast into the molds and the parts have been heated sutlieiently to be welded. According to tests ithas been found that one and onehalf minutes sufiice for heating the rails suficiently for Welding the same. y

After the process has been carried out in the above-described way the molds are taken off andthe alumina coating is knocked of,

so that a rail is obtained, as shown in Fig. 3, in which figure a2 is the lish-raihand g is'a knob formed ingo by thefoverlowing metal,` which knob is afterward also knocked off.

In the modification shown in Fig. 4 two separate openings e e for the alumina and the iron are provided. Through the open-r ing c the alumina and through e. the molten iron is cast into the molds. The process is carried out in the saine way as described In'Fig. 5 a mold is shown Vconsisting of two parts separated in line m m, so that on one side fr of the rails the alumina and on the other. sid-e r of the rails the iron is ca st. The fish-rail t would be arranged in this case only on one side of the railsl and would extend to a certain height g.

The process may be carried out also in another way. Thel topA mold in Fig. l might beenlarged so as to receive the whole mass, consisting of the molten alumina and the iron.v Then a hole is punched through the bott-om of the mold, whereby the molten against each othenin such a manner that a i displacement during the heating' of the pieces by means of the reaction mass is renl derecl impossible.

iron 'flows through this -hole around the lower part of the rails.

Anothcrvform of arrangement 1s shown 1u Fig. (3,-in which the two molds are not ar .process into effect is illustrated in Figs. 7.

8, and 9.A In these Iigures l is a mold. Q is a crucible situated above the same and provided with a tap-hole 3, which tap-hole may be cl-osed by means of a plug or, as shown in the drawings, by means of a plate l0, consisting of sheet-iron or the like. 6 is therek action mass. 4 are the rails tol be joined. As lwill be seen from the drawings, the. crucible is situated so that the tap-hole 3 is not situated vertically above the head of then rail. v 1f the lreaction mass G is ignited, the highly overheated metal 7, Fig. S, melts/,the plate 10 and flows into the space 5 ofythe mold l and from there around the foot if the rail, as may be seenjfrom the drawings, the alumina S flowing out after the metal Hows around the uppery part of the rail, as will be seen from 9. It will be understood that instead of arranging a special crucible l.above the mold this-moldmay be provided with a funnel l2 on its top, in which funnel the mixture can be filled.

Contrary tothe known process consisting in casting-metals around the lower part of the railsby the process described above .a better welding or joining of the metal cast around the rail-foot with this rail-foot is `attained by the high superheat of the metal,

whereby it is attained that the joining faces arejoined in such a way' that one continuous metal piece is formed; l

Having thus fully described the nature of my said invention, what I 'desire to secure by Letters Patent of the United States isl. Process of joining metals by meansI of the heat arising by the reaction taking place when pulverized aluminium and redueiblny oxygen -containing metal compounds are mixed and this mixture is ignited, said process consisting in casting the highlybverheated molten metal arising by the reaction directly around one part of theI metal pieces to be joined, and t-he molten alumina around another part of these metal pieces, substain tially 'as described and for the piu'pose set forth.

2. Process of joining metal pieces consisting in surrounding the ends to be joined with a mold, filling a. crucible provided with a tap-hole in the bottom with a mixture consisting of aluminium and a reducible oxygen-containing metal compound, bringing the Crucible above the mold in that way that the tap-hole is not situated vertically above the' parts to be joined, igniting the mixture contained in the crucible and opening the tap hole of thecgsame, substantially asY described land fr the purpose set forth.

ignition of the mixture l"mentioned"above, K

bringing the crucible above the mold in that Way that the tap-hole is not-situated veitically above the metal pieces to be joined and igniting the mixture contained in the crucible, substantially as described and for the purpose set forth. A u

4. A process of weldin metal Whicn consists in lgniting in a Crucible a mixture of a reducible metallic compound and aluminium and causing the. molten metal to discharge from the Crucible into contact with a metal p`a'rt in advance of the molten slag.

In testimony whereoflI have signed my name to this specification in the presence of two subscribing'witnesses. l

HANS GoLDsoHMinT.

Witnesses:

WOLDEMAR HAUPT, y HENRY HASPER.

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