US1721688A - Chill for casting railway crossings - Google Patents

Description

July 23, 1929. w. BRINTON 1,721,683

CHILL FOR CASTING RAILWAY CROSSINGS Filed Nov. 5. 1927 2 sheets-sheet 2 00000000 f :ur g /k OOOOOOOO i LD @QQQQQ 00000000 5 im ;-@@@000 00000000 j "l @@QQQGOO 00000000 I @@@QO000 `-1 00000000 @05300000 00000000 00000-000 00000000 i 00000000 00000000 4 00000000v Jgx Zaz/efczr rL//ZO/z CAD Patented July 23, 1929.

UNITED STATES PATENT oFFlcE.

WALTER BRINTON, OF WILMINGTON, DELAWARE, ASSIGNOR TO AMERICAN MANGA- NESE STEEL COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF MAINE.

CHILL FOR CASTING RAILWAY CROSSINGS.

Application lled November 5, 1927. Serial No. 231,203.

This application is a continuation of my application Serial No. 115,643, filed June 12, 1926, which was a division of my application Serial No. 25,226, filed April 23, 1925. Hence, this application is a continuation in part of my said application Serial No. 25,- '226. i

This invention relates to the production of steel castings in form which renders them suitable to constitute the intersecting portions of railway rails at track crossings, and particularly to -crossing members employing in their form, tread surfaces, flangeivays, and guard-rails, all in one integral structure. It has heretofore been proposed to use, in the production of molds for these crossing members, chills which will have the effect of improving the texture of certain portions of the surface of the metal, for instance.l chills in the form o f round rods in position to give form to the bottoms of the grooves or flangeways, but these chills, except for improvement of the immediate surface which they defined, did not substantially improve thecasting as a Whole, for the reason that they left lrelatively large masses of the casting constituting the sides of the flangeways as Well as the surfaces of the tread and guard, Without material structural change. I have discovered by experiment and observation that a cause of failure which is encountered in a substantial proportion of cast crossing members arises from the fact that the relatively thin supporting webs and base flanges of the crossing member cool too quickly in comparison with the tread, angeway, and guard portion which collectively involve a substantially greater mass, with the result that contraction incident to cooling of the last-named areas after the first-named portions have become set, results in undersirable drawing and attenuation of the metal, and leaves the piece under injurious stresses.

Now, one object of the present invention is to devise a chill for use in casting railway crossing members which will have the eect of coolingnot only the langeways but the tread and guard portions, and in fact, the Whole of the greater mass area of the casting, suliciently in advance of the cooling of the remainder of the casting to insure a free and unretarded flow of metal inward toward the greater mass, and thereby produce the desired density and texture of the metal in this mass and do away with the inherent conditions which detract from the durability and resistance to cracking of the member when in service. To this end, the invention consists primarily in a chill member for use in producing the portion of the mold which defines the flangeways and their Walls, the tread surfaces, and the upper surfaces of the guards, which chill member has the effect of causing rapid setting of such portions of the casting as Well as areas adjacent thereto; While the supporting webs which extend from such chill cast portions are retained by the relatively large surrounding mass of sand at a temperature which permits the metal to How freely through or past the web forming cavity to the chilled portions, especially if the mold be provided with runners contiguous to the web portions, for instance, runners Which manifest themselves in the form of -sWells or enlargements on the web or side Walls of the channel in the ultimate casting, and which increases the flow capacity past the relatively thin Web portions and into the greater mass area of the tread-guard, and flangeway.

Another object of the invention is to provide a chill for the purpose stated, which Will have a lrage conducting capacity when used in accomplishing the first-named object; and, to this end, another feature of the invention consists in constructing the chill not only With intersecting ribs conforming in section and location to the flangeways to be formed, but With a plate which provides those confines of the mold which give form to the tread and guard surfaces, which plate is integral with and constitutes the carrier for the flangeway ribs; the plate being preferably extended' Well beyond the areas of the surfaces which it is to form, for instance, by having its intermediate portions stand in the .relation of heat-conducting diagonals to the intersecting elements of the crossing, thereby increasing the heat dissipating area and more nearly maintaining equilibrlum of temperature and setting throughout the chilled parts.

In the accompanying 'drawings- Figure 1 is a perspective view yofa cast metal ,crossing member of typical design, as seen from above. u

Figure 2 is a perspective view o f tlm chill.

Figure 3 is a sectional view. 1n a plane which would errespond te the line 3*"3 0f Yso and guard-forming surfaces 10; and this Figure 1, and showing the chill assembled therewith. y

Figure a is a vertical sectional view of .a portionlofthe track member ywith a modilied design of tread surface pads for cold working.

Figure 5 is a plan view of a form of chill for producing the track surface of Figure L1; and

Figure 6 is a detail view in vertical transverse section showin@` the complete mold with the chill and casting in the normal inverted positions therein.

'Referring to Figures 1, 3, and (i, `1 represents the tread portions, 2 the guard portions,3 the iiangeways, 4l, 5 the vertical webs, and G the base flanges of a railroad crossing member of known design, whichis generally produced by the art of casting, and which, for the sake of increased wearing qualities, is generally'made of manganese steel. Owing to the reduced section'of the parts et, 5, and G, it frequently happens that these portions of the casting, as ordinarily molded, take on algset in advance of the portions 1, 2, and 8 of greater mass, with' the result that as the portions 1, 2, and 3 cool, there is lacking the free fluidity of the metal which enables them to draw from the risers during contaction incident to cooling, in consequence of which the structure of the metal deteriorates, the parts wear more readily when in use, and cracking is liable to occur at the weakest point, namely, at the intersection of the flangeways 3. To remedy this difficulty, the present invention provides that part ofthe mold which gives .shape to the flangeways 3 and to the surfaces 1 and 2, in the vform of a chill 7 (Figure 2) which comprises in its design flangeway ribs 8, tread-forming surfaces 9,

chill constitutes the metal receiving surface at the bottom of the cavity in the drag section of the mold, as suggested in Figure 6. In addition to forming the faces 8, 9, and 10 described, the chill 7 involves in its form heat dissipating areas 11,12, and 13 'related as diagonals to the tread and guard surfaces described, equahing the heat between the several branches of the casting, and extending into the sand of the moldin a. manner-to increase heat dissipation, besides rendering the chill more secure against warping than if itwere restricted to the outline of the surfaces which it is to form.

Theribs 8 of the chill 7 which form the flangeways 3 of the track member are tapered with their sides at from 5 to 10o to the `perpendicular as suggested by the dotted construction lines in Figures 'and l, in a transverse direction from the chill plate upwardly, .with several advantages, among which are the provision of a sufficient draft to the portions of the chill which enter the casting to facilitate withdrawing the casting from the chill; the corresponding increase of metal mass and consequent improvement of the tread surfaces, particularly at the intersection of the flangeways where pads are formed as a step in solidifying the points of the intersecting treads; and the chilling of the pads which insures superior texture of the metal in its function of solidifying points is thus rendered even more effective.

@hill 7 involves the further novel feat-ure of cavities 14 corresponding in position to the points of the rail treads, with their marginal portions defined by the ribs 8, and producing the raised pads vof metal la shown in Figure 1, which in `finishing the casting are pressed down into the vplane of the surface of the fisting, thereby densifying and improving. the text-ure of the metal. The isolation of the pads 14 in the recesses 1-1- and the defining of Vthese recesses by metal walls forming part of the chill member, and particularly with the relatively large adjoiningl masses afforded by the ribs 8, will insure the solidity of the densifying pads 14ea and the'performance of their function of raising the character of the metal at the meeting points of the intersecting treads when the pads are depressed into the plane of the treads,

According to a modification of tread surface embodied in the track member as illustrated in Figure 1, produced by the chill shown in Figure 5, the raised pads formed on the casting for theV purpose of being depressed into the mass of metal of the track member, are in the form of numerous small approximately hemispherical protuberances 14ax (Figure 4;) formed by cavities 14X (Figure 5). The areas covered by these densifying protuberances will preferably approximate that shown by the groups of plain circles in Figure 5, and preferably the densitying will be rendered more intense at the point where excessive hammering takes place by making the protuberances deeper, as suggested by the shaded circles 14x in Figure 5.

As a means of permitting the metal to promptly respond to the cooling influence of the chill 7, How-ways or runners manifested in the finished casting by the lugs 15, are cored in the sand, which` defines a web or side wall of the channel of the crossing, and at vantage points therein with respect to eicient feeding of the metal, and these runners, being beneath the risers 16 and extending past the relatively thin web portions 4l of the casting and preferably intermediate of the ends of each arm of the cross, insure an ample supply of molten metal to feed the greater mass area during cooling.- Y

In a castingy made with a mold utilizing the chill described, the portions of the'casting which are subjected to the greatest .stresses in use will be insured as to density lee of metal, first, by causing such portions to be cooled in advance of other portions and while the other portions are still in a fluid state and therefore enabled to feed metal to supply contraction; and` secondly, by increasing the flow capacity toward the greater n'iass areas'.

I claim:

l. A chill for casting railway crossings, comprising a base portion adapted to dene tread surfaces of the casting, and intersecting ribs adapted to define the flangeway portions of the casting.

2. A chill for casting railway crossings, comprising a. base portion adapted to define tread surfaces of the casting7 and intersecting ribs adapted to define the flangeway poi'- tions of the casting; the ribs being tapered in cross section from the base portion upward.

3. A chill for casting railway crossings, comprising a base plate adapted to present its surface in the plane of tread portions of the castings to be formed, and intersecting' flangeway ribs rising from said surface.

4. A chill for casting railway crossings,

comprising a base plate having faces in position to define intersecting tread portions of the crossing; said plate having extended areas related as diagonals to said intersecting tread portions.

5. A chill. for casting railway crossings, comprising a base plate having faces in position to define intersecting tread portions of the crossing; said plate having extended areas related as diagonals to said intersecting tread portions; said chill also having intersecting flangeway ribs rising from the plane of said faces.

6. A chill for cast railway crossings, comprising a base plate having faces in position to define intersecting tread portions of the crossing, fiangeway ribs rising from said plate in position to define intersectingv flangeways in a casting, and cavities in the corners formed by the intersecting flangeway ribs designed to produce raised pads upon the meeting portions of the treads of the crossing member.

Signed at Wilmington7 Del., this 27th day of October, 1927.

WALTER BRINTON.

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