US1917868A - Hood for welding molds - Google Patents

Description

y 1933- E. F. BEGTRUP v HOOD FOR WELDING MOLDS Filed April 9, 1932 H l5 ATTORNF Patented July 11, 1933 1 v nnwann r. nineteen, or JEnsnY orry, NEW JnnsEY' noon Ion WELDING means Application filed A t-n s,

This invention relates to certain improvements in the welding of rails by s'uperheat' ed molten metal, such as alumino-thermic steel, and has for its object to provide a novel {5 and highly efiicient means tobe associated with the mold to expedite the preheating of the mold and the rail ends enclosed therein, said means comprising hood adapted to overliethe top ofthe mold and being provided 1.- withan imperforate double arched top, which will cause the rising combustion products to be deflected downward against the rail heads and to be vented along the surfaces of the rail heads, thereby causing the combustion '15 products to give up much larger proportion of their heat units to the rail heads than was possible of realization with-the former types of hoods.

The invention is illustrated in the accom- 2 panying drawing, in which Fi 1 is a sectional elevation of a typical rail welding mold adapted for use without interrupting traflic, the new hood of my invention being applied thereto.

Fig. 2 is a perspective view of the hood.

In the alumino-thermic welding of rails,

without interruption to traflic, it is common to employ a three part refractory mold to enclose the rail ends, including a two part hase section and a removable cope section, the mold being fashioned to enclose the rail ends which areiseparated from the interior mold walls by surrounding spaces into which the superheated thermitsteel is poured so as to surround the rail ends and fuse therewith to form a substantially uniform weld. The two lower mold sections enclose the rail ends to substantially the level of the treads or running surfaces thereof andfthe upper or cope section is fitted to and constitutes the completing supplement to the lower sections and is separately removable to permit passage of traffic during the preliminaryoperations of placing the mold and preheating the interior of the mold and rail ends prior to the actual pouring of the thermit steel. The refractory cope or upper section is usually pierced by one or more openings leadinginto the mold cavity, such, for example, as the pouring gate and the riser or vent, which 1932/ Serial at. 604,207.:

are usually disposed on opposite sides of the mold, with referenceto the rail heads. In order to avoid the necessity, of removing and replacing the refractory cope to accommo date passing traffic during the preliminary operations, as aforesaid, it has'beii custommy to apply-to the top of thelower mold sections a generally dome-like hood which spans the openings inthe main body of the mold and is intended to retain the products of combustion from the blow torch or similar preheating device in contact with the heads of the rails enclosed within'the mold, the hood being provided with a vcntjopening'in its top to permit the escape ofthe combustion products; This particular type. of hood has been reasonably effective in preheating the rail ends, but, owing to its general form and the location ofthe vent in the highest point thereof, a very considerable portion of the hot gases escape through the vent without coming into physical contact with the rail ends, so that much of the heating effect of these gases is lost. The preheating of the rail ends in a mold ofthis character and =employing a hood of the form described usually requires about thirtyiminutes, during which time, if the traffic is frequent, numerous car wheelswill have passed over the site of the joint and it is quite evident that the arring and hammering of the wheels at the joint have a tendency to injure and disintegrate the mold, especially as the latter becomes more frangible as it reaches the higher temperaturesdesired in the preheating. For these reasons, as well as that of economy of labor, it is highly desirable that'the necessary degree of preheat of the rail ends and the interior of the mold, prior to the actual pouring of the molten metal, be'accomplished in the shortest possible time and the instantinvention is designed especially to meet these. conditions, r Referring to the drawing, 1 and 2 indicate the lower sections of the refractory mold adapted to enclose the ends ofthe rails to be "welded to substantially the level of the tread surface of the rails, the mold sections being provided with the usual cavities defining the space into which the superheated molten understood by those skilled in the art. These cavities extend to the top of the mold sections and define the collar or protuberance, which I characterize welds of this type.

As stated, it is customary and, in fact, necessary to preheat the mold and the ends of the rails enclosed therein preparatory to teeming superheated molten metal into the mold to'efiect the weld. This preheating is effected by means of a blow torch or the like, the flame of which is directed through a preheating gate formed in the lower part of one of the mold sections, such as indicated at 10, and the products of combustion flowing through the mold cavity, and about the rail ends would quickly escape from the mold, if the latter were not provided with a cope or a hood to confine the combustion products as much as possible. It is inexpedientto use the regular cope during thefpreheating operation, because of the labor involved in the frequent removal and replacement there'- of to accommodate traliic and also because of the likelihood of damaging the cope or the 'mold by such removals and replacements.

The ordinary dome-shapedhood with a top vent will obviate the 'ClIillCLlltIQS and ob ections incident to the use of the retractory cope, but, as stated, it is more or less waste-- ful of the combustion products and, therefore, inefiicient as a means for-preheating the mold and the rail ends, both in the expenditure of time and preheating fuel. The new type of hood embodying my invention, however, avoids all of the noted objections and provides a means for effecting the necessary preheating of the rail ends and the interior of the mold in the shortestpossible time.

As shown in the drawing, the hood comprises a hollow metal casting 3 having perpendicular end walls 4;, the lower edges of which are fashioned to conform to the upper surfaces of the mold sections 1 and 2 and the upper surfaces of the rails, except at points adjacent the heavier portions of the rail heads where the lower edges are cut away to provide vents 7 immediately adja cent the rail heads. The top and sides of the hood are formed as double arches 5 and. 6, which are joined ina line substantially above and in general alignment with the heavier portions ofthe rail heads, the lower edges of the sides closely engaging the top surface of the mold sections. For purposes of convenience in handling, the hoodis provided with a bail 8 or other suitable handle by means of which the hood may be readily applied to and removed from position.

As indicated'by the arrows in the drawing,

portions of the rail heads and can escape oniy by way of the vents 7, so that the said products are kept in contact with the rail heads as long as possible, with the result that hey give upa large amount of their heat units to'the rail heads, which heat units would have been wasted in the older type of hood;

While the mold and the hood have been illustrated as of the type employed for welding girder or trilby rails, it will be understood that the invention is not limited to this particular type, but is equally applicable to the welding of ordinary T-rails and rails of any other standard pattern, themold sections and the hood being appropriately fashioned to cause the products of combustion to be deflected downward againstthe rail heads, to circulate thereabout and to be discharged or vented ultimately along the surfaces adjacent the heavier portions of the heads.

What I claimis:

1. A hood forwelding molds, comprising end walls having lower marginal edges substantially conforming to the top of the mold and the top surfaces of the rail heads and having limited sections adjacent the latter cut-away to provide vents, and a double arched wall forming the sides and top.

2. A hood for welding molds, comprising end'walls having lower marginal edges substantially conforming to the top of the mold and the top surfaces of the rail heads, and a double arched wall forming the sides and top.

In testimony whereof I aflin my signature. I

EDWARD FIBE TRUP.

Images