US1914878A - Cope for rail welding molds and method of forming the same - Google Patents

Description

June 20, 1933. E. F. BEGTRUP v 1,914,878

CGPE` FOR RAIL WELDING MOLDS AND METHOD OF FRMINGl THE SAME Filed April 9, -1932 2 Sh''e'ts-Shee'c l INVENTOR Edward; E B egujv dvb-W June 20, 1933. E, F. BEGTRUP COPE FOR RAIL WELDING MOLDS AND METHOD OF FORMING THE SAME Filed April 9, 1932 2 Sheets-Sheet 2 @.4

INVENToR Edward Flegwfz BY bh-bx" HIS ATTORNEY Patented June 20, 1933 UNITED STATES PATENT OFFICE EDWARD F. BEGTRUP, F JERSEY CITY, NEW JERSEY COPE FOR RAIL WELDING HOLDS AND METIIOD 0F FORMING THE SAME Application ledrv April 9, 1932. Serial No. 604,205.

The invention relates to certain improvements in the art of welding rails by the alumino-thermic or analogous process, which includes the enclosing of the rail ends in a a mold of refractory material to receive the 0 lower mold section and a cope section adapted to be applied to the lower section; the in.- stant invention being concerned with the novel method of forming the refractory cope, which latter is constructed in situ, thereby avoiding the use of special patterns and insuring that the mold cavity in the cope will conform properly to the contour of the rail heads.

The application of the method in connection with the welding of girder or trilby rails is exempliiiedyin the accompanying drawin s, in which `ig. l is a perspective view of the ends of the rails to be welded, in which the rail ends are either mismated or worn.

Fig. 2 is a section on line Q-Qvof F ig: 1.

Fig. 3 is a transverse sectional elevation through the mold with all of the parts in position for the pouring opera-tion.

Fig. 4 is a plan view of the cope with its refractory material omitted.

Fig. 5 is a perspective detail of a parting strip for bridging the gap between the rail ends.

When the alumino-thermic welding of railway rails is to be effected without interrupting traffic, it is customary to employ a mold comprising two lower or main mold sections enclosing the rail ends to substantially the level of the tread surface of the rails and an upper or cope section fitted to and constituting a completing supplement to the lower sections, the cope being removable to permit the passage of traffic during the preliminary operation of preheating the interior of the mold and the rail ends enclosed therein. Y

Heretofore the making and application of the refractory cope has been accomplished in a number of ways, all of which have undesirable features., One such method has been to prepare a pattern or pattern print having thecontour of the rail heads and the mold top, which pattern is applied to the usual cope frame, and the refractory material to form the cope then rammed in place. The cope thus formed is applied to the upper face of the two-part lower mold member with the upper faces of the rail heads fitting the cavity or impression formed in the cope by the pattern. With such a cope, it is difficult and, in the case of badly worn or misaligned rail ends, it is practically impossible to make a tight or close lit between the cope and the rail heads and the top surface of the main mold, wherefore it is necessary to further ram the refractory material or seal the joint between the cope and the rail heads by luting, or by both ramming and luting, after the cope has been applied to position, usually after the preheating of the rail ends has been effected. While Vsuch procedure prevents an actual run out or escape of the superheated molten metal beemed into the mold, it is objectionable because it results in fins or projecting portions of the metal of the weld, which must be subsequently removed.

Another mode of forming the cope, as heretofore practised, consists in first preheating the main body of the mold with the enclosed rail ends in the usual manner, involving the employment of a hood spanning the open top of the mold and, after the preheati'ng has been effected, removing the hood, placing the cope frame in position and then S5 ramming loose sand or other refractory molding material directly over the preheated rail heads and the top surface of the lower mold portion. This procedure is also objectionable for several reasons, for example, the pre- 90 heatedl temperature of the mold and rail ends drops rapidly during the interval of time required to ram such cope, due to the absorption of the heat by the loose damp sand being rammed into direct contact with the preheated rail ends; the moisture from the rammed sand is retained inthe mold structure and produces blow holes or other objection able defects in the weld; the time required for ramming causes delays in the passage of trafhc, especially if the traiiic is frequent; and the practical difhculty of forming desirable weld collars over or partly over the rail heads and/or the rail lips.

The instant invention is designed to effect the. production of satisfactory and effective copes in a. manner to avoid all of the difliculties aforesaid and the procedure, as applied to the welding of girder or trilby rails, is as follows:

The rail ends r, r are brought into alignment in the relation indicated in Fig. l so that the tread surfaces will be in the same plane, the ends of the rails being separated by the usual gap, which is partly bridged by the customary insert 1 applied between the adjacent faces of the rail heads. The rail ends are then enclosed in a longitudinally divided lower mold, consisting of the sections 2 and 3 of refractory materialrammed into mating flask sections or frames over suitable patterns to define the mold cavity, which latter receives the superheated molten metal to e'fl'ect the weld. The mold sections 2 and 3 at their upper sides extend to substantially the level of the tread and lip surfaces of the rail ends, so that the wheels of traffic may pass over the joint without contacting the mold sections. At this stage of the proceedings, according to the former practice, it was customary to apply a hood to the open top of the mold and then preheat the enclosed rail ends and the interior of the mold by the products of combustion produced by the flame of a blow torch or the like introduced through the usual heating gate in the lower part of one of the mold sections, and, after the preheating had been effected, the hood was removed and the preformed cope was placed in position, or, as stated, the cope was formed by ramming the loose refractory material into the cope frame or flask section which had been positioned above the main flask section. in lieu of these former practices, it is the purpose of the present invention to form the cope in situ, before the preheating of the rail ends is effected. In doing this, there is first placed in the lips or grooves of the rail ends a relatively thin shim or parting strip preferably of sheet metal, which may be readily deformed to accurately fit the surface contour of the groove or lip and which, when positioned, will span the gap between the rail ends at this point and will, in fact, constitute a pattern to define the welding collar which it is desired to form at this portion of the welded oint. As shown, this shim or parting strip also extends to and overlaps the adjacent portion of the upper surface of the mold section 2. A similar parting strip 5 is positioned over the outer edges of the rail ends and overlies the adjacent top surface of the mold section 3, spanning this portion of the gap between the rail ends and also defining the collar formed by the welding metal in this area of the rail heads. Preferably associated with the shim or parting strip 5 is a core or pattern G, which defines the vent or riser.A

In case the rail ends are mismated or irregularly worn, the tread surfaces thereof are brought into horizontal alignment, after which the strips 4 and 5 are pressed or otherwise worked into close surface contact with the adjacent faces of the rail heads. The strip 4 at the groove or lip side of the rails is preferably formed of a. ductile material, preferably of relatively lsoft sheet lead, so that the necessary deformation thereof to effeet a close lit between the same and the portions of the rail heads with which it engages may be readily eii'ected, even though the corresponding portions of the rail heads may be out of alignment with each other or otherwise lnismated.

After the parting strips have been properly applied to position, the cope frame or flask section, such l0, then placed in position ou the upper surface of the body of the mold surrounding the opening in the top of the latter, and the refractory material is then applied to the section l() and rammed until it becomes firm and self-sustaining in the frame with its lower face conforming to the contours of the engaging portions of the upper faces of the mold sections 2 and 3, the upper faces of the parting strips 4.- and 5 and the exposed surfaces of the rail heads. After the ramming has been completed, there is produced a ref `actory cope, the lower face of which conforms exactly to the contour of that portion of the rail joint adjacent the upper faces of the rail ends to be welded. It will thus be seen that the under face of the refractory cope will be an exact counterpart of the upper portions of the oint regardless Of any misalignment or wear of the rail ends, or the displacement of the top faces of thc half mold sections 2 and 3. Then the cope section has been thus completed in situ, it is removed and the parting strips 4 and 5, which may adhere to the under surface thereof, separated therefrom and the cope then set aside for air drying, or, alternatively, it may be slightly skin dried by the application of heat, or completely baked and dried, as desired. In any event, it is preferably completely dried before it is subsequently applied to the mold during the completion of the welded joint.

The prcheating of the mold and the rail ends is effected after the cope has been formed in situ, as described, and, when the preheating has been completed, the cope is firmly seated in engagement with the upper faces of the mold sections 2 and 3 and the exposed portions of the rail heads in exactly the same position in whica it was formed, so that, generally speaking, the lower face of the cope will accurately define the upper boundaries of the mold cavity. However, as some eX- pansion may have taken place in both the rail ends and the mold during the preheating and possibly some slight upsetting of the rail heads, these slight changes or discrepancies in the contour of the parts may be compensated for by providing the cope section l() with projecting flanges or luting strips l2 applied to its inner walls, so that, when the cope is pressed home, these luting strips will exercise the necessary pressure on the subjacent portions of the molding material to cause the latter to effect a tight seal with the underlying portions of the rail ends and the tops of the main mold sections 2 and 3. In order to make these self-luting strips effective, the cope shell or flask section, when first applied to the top of the mold sections 2 and 3, is lightly pressed into position sufficient to leave tell-tale marks in the molding material of the said sections 2 and 3, after which the refractory material is filled into the shell or iask section and rammed as described. Upon replacement of the cope, after the preheating operation, it may be accurately positioned by engaging its lower marginal edges with the tell-tale marks aforesaid and tapping the cope frame sharply on its upper edges to force the lower edges into a tight sealing seat, the lower edges or supporting projections on the lower edges of the cope shell being forced deeper into the refractory material of the mold sections 2 and 3, as shown in Fig. 3, thereby carrying the entire cope downward to a corresponding degree, so that the luting strips 12 will force the refractory material of the cope immediately below said strips into engagement with the subjacent parts of the mold and the rail heads.

When the cope has been thus properly positioned, the welding operation may be completed by teeming the superheated molten metal into the mold in the usual manner.

As stated, the shim or parting strip 4 is preferably made of thin ductile material capable of being readily worked and deformed into the contour of the groove or lip portions of the rail ends with which it is to be engaged, but in the welding of T rails, not having any groove or lip portion, the use of ductile material for such parting strip would obviously be unnecessary. Concerning the strip 5 which supports the pattern or core 6 for defining the vent or riser in the refractory material of the cope, this is preferably made of thin sheet copper, to the under side of which is secured one or more dowel pins G, which are driven into the upper face of the lower mold section during the ramming operation and serve to hold the strip in position. These sheet metal shims or parting strips 4 and 5 are also effective in securing the clean separation of the refractory material of the cope from the subjacent surfaces against which the material was rammed in the forming operation.

While the invention has been particularly described with reference to its application to welding girder or trilby rails, it will be understood that it is equally applicable to the welding of ordinary T-rails and rails of any other standard patterns.

What I claim is:

l. In the method of alumino-thermically welding rails ends, enclosing the rail ends in a sectional mold extending to substantially the level of the rail treads and forming the cope section of the mold in situ prior to preheating by compacting the refractory material of the cope section against the top surface of the rails in a frame supported at the top of the sectional mold and the tops of the rail ends.

2. In the method of alumino-thermically welding rail ends enclosed in a sectional mold, applying a thin parting strip or strips to span the gap between the rail ends, placing a cope frame on the top of the sectional mold and the tops of the rail ends, and applying and compacting the refractory material of the cope within said frame prior to preheating.

3. In the method as set forth in claim 2, shaping the parting strip or strips to conform to any irregularities in the surfaces of the rail endsto bey engaged thereby.

4. In the method of alumino-thermically welding rail ends, enclosing the rail ends in a sectional mold extendingr to substantially the level of the rail treads, applying thin parting strips to the tops of the rails to span the gap between the rail ends, placing a cope frame over the top of the sectional mold and the rail ends, ramming refractory material in the cope frame to form the cope section prior to preheating, removing the formed cope section and the parting strips, preheating the mold and the rail ends, and finally reapplying the cope section to the top of the sectional mold.

5. In the method of alumino-thermically welding rail ends, enclosing the rail ends in a sectional mold extending to substantially the level of the rail treads, applying thin parting strips to the tops of the rails to span the gap between the rail ends, placing a cope frame over the top of the sectional mold and the lOf rail ends, ramming refractory material in the cope frame to form the cope section prior to preheating, removing the formed cope section and the parting strips, preheating the mold and the rail ends, reapplying the cope section to the top of the sectional mold, and finally pressing the refractory material of the cope section adjacent the ends thereof into sealing engagement with the underlying portion of the rail ends and the top of the sectional mold.

In testimony whereof I affix my signature.

EDWARD F. BEGTRUP.

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