US2110455A - Mine car wheel and method of making the same - Google Patents

Description

March 8, c STEELE MINE CAR WHEEL AND METHOD OF MAKING THE SAME Filed Aug. 15, 19:56 2 Sheets-Sheep 1 March 8, 1938. c, STEELE 2,110,455

MINE CAR WHEEL AND METHOD OF MAKING THE SAME Filed Aug. 15, 1936 2 Sheets-Sheet 2 NNNNNN OR Patented Mar. 8, 1938 UNITED STATES MINE CAR WHEEL AND METHOD OF MAK- ING THE SAME Charles M. Steele, North Irwin, Pa., assignor to Irwin Foundry & Mine Car Company, Irwin, Pa., a corporation of Pennsylvania Application August 13, 1936, Serial No. 95,802

2 Claims.

In the accompanying drawings which illussl trate my invention:

Figure 1 is a central vertical section through a mold flask for casting an improved wheel embodying my invention;

Figure 2 is a bottom perspective view of the annular chill forming a part of the flask shown in Figure 1;

Figure 3 is a bottom perspective view of a baked core with segmental chills embedded in its periphery;

Figure 4 is a top plan view of the baked core shown in Figure 3, partially broken away to show a segmental chill embedded therein;

Figure 5 is a view in side elevation of the cast mine car wheel.

Figure 6 is a sectional view taken on the line VI-VI of Figure 5;

Figure '7 is a fragmentary sectional view illustrating the relation of the inner and outer chills to the tread of the wheel, this view being taken on the line VII-VII of Figure 6 with the chills added;

Figure 8 is a cross section through the tread and the chills taken on the line VIII-VIII of Figure 7.

The present invention has grown out of the increasing demands placed upon mine car wheels. Mine cars are carrying heavier loads while at the same time the diameter of the wheels has remained the same or has even been decreased. 40 Consequently, the wearing away of the treads of the wheels has decreased the life of the wheels to such an extent as to become a problem.

Cast-iron wheels have the advantage that the tread may be chill-cast. It is the chilled por- 45 tion of the rim of the wheel which resists wear, and therefore, the thickness of the chilled tread determines the length of life of the wheel. In accordance with the present invention, the depth of chill of the tread is increased by using both 5 an inner chill and an outer chill for the tread when casting the wheel.

In setting up the mold flask shown in Figure 1 for casting the car wheel, I prefer to prepare the cope ID, the cores H and I2 and the drag I3 separately. The cope is provided with the usual ribs l5 for maintaining the sand therein when the cope is lifted to its position on the other parts of the flask. The patterns for forming the green sand in the cope and drag are not shown, since this sand will be compacted in the cope and in the drag in the usual manner so as to present the upper and lower mold cavity surfaces as indicated in Figure 1. The drag may rest upon any suitable sup-port such as the plate l6 shown in Figure 1. i

The core 12 presents features of novelty in that segmental chills l8 are embedded in the sand, after which the core is baked with these chills embedded therein. A two-part mold is preferably employed for forming this core l2, as will be understood by those skilled in this art.

It will be noted from Figure 1 that the flask is arranged for casting the wheel 20 with the flange 2i downwardly. Part of the flange is formed in the sand of the drag l3 and the remainder of the flange 2| is formed by an annular recess 23 along the lower inner portion of the annular chill 24.

The flask is assembled with the annular chill 24 intermediate the cope l0 and the drag I3, the core ll extending vertically through the center of the mold cavity, and the core l2 arranged coaxially with the annular chill 24. A gate through the central portion of the top of the cope is provided for pouring the molten metal into the mold cavity. The molten metal fills the mold cavity and the excess metal forms the customary sprues. The impurities which go to make up the segregate tend to rise, so that the flange 2| is formed of purer metal than is the case when the flange is cast uppermost.

The resulting wheel 20 is illustrated by Figures 5 to 8 of the drawings. The hub portion 26 is merely illustrative, for its form can be varied to provide the type of bearing desired. The rim portion 21 includes the chilled tread 28, the flange 2! and a shoulder 29 which forms, at the other side of the tread from the flange 21, a continuation of the tread.

Between the central hub portion 26 and the rim portion 21 extends a connecting portion 3|, which is integral with the hub portion and the rim portion. This connecting portion does not follow established practice, because I leave open spaces or recesses beneath the tread 28 to accommodate the segmental chills I8 during casting. In accordance with my novel arrangement of this connecting portion, I support the hub portion 26 from the rim portion 21 in part by a web 32 and in part by spokes 33.

In the embodiment shown, the web 32 takes the form of a disc cast integral with the hub 21, being integrally connectedwith the shoulder These spokes include a portion 33, which extends across to the? disc or web'32. This arhas an important function in the wheel. The

rangement accords with my purpose of having the spokes recessed beneath the wheel tread.

,Figures '7 and, 8 illustrate theefi'ectlof the inner and outer chills on the grain structure of the tread. The outer chill hardens the cast metal both on the wearing surface of the tread and on the wearing surface of the flang'e. Due

to the use of the inner chills [8, the body of hardened metal extends substantially completely through the tread so that the wear-resisting metal continues to be exposed by the wearing away of the. surface of the tread until the rim portion 21 is too muchworn away'for further use of the wheel.

The'unhardened metal in the rim portion 21 hardened: metal is brittle, and while it' is highly wear-resistant it does not have the strength of. the-unhardened metal.

The latter extends outwardly alongthe outer side ,of the'flange 2l and into-the shoulder 29 to reinforce the hardened metal in the tread 28. I

A wheel embodying myinvention has; therefore, the advantage of resistance towear to the very end'ofthelife of the wheel without sacrificing toughness and ability to withstand shocks.

castabcut this solid ring.

therefore, that while I have illustrated and de- The form of wheel shown is to a large extent illustrative merely of the invention. As has been above mentioned, the design of the hub portion can be varied so that the desired type of bearing may be employed. It is not necessary that the inner chill be removed from the wheel after castingsince this chill could be left as a part ,of the finished wheel. In such a case, a solid ring would be embedded in' the core l2 and the wheel Itwill be understood,

scribed the embodiment of my invention which I atpresent prefer, the invention may be other- I'claim:

'1 A .car wheel having ahub portion, a'rim portion including a flange and the wheel tread, and aconnecting portion :extending between the hubportion andthe rim portion and integral therewith wherein. said connecting portion and the outerpart at least'of the 'fiang'e are substantially without chill as ca'stand said tread is chilled both from within and'fromwithout. v t

2. A car wheel'having a hub portion, a rim portion including the wheel, tread, aflange on one side of thetread and ashoulder forming a continuation at the other side of the tread, and a connecting portionextending between the hub wise embodied and practiced within the scope of r the following claims.

portion and the rim portion wherein. said connecting portion, said shoulder and the outer' part at least of the flangeare substantially with- 1 out chill as cast and said tread is chilled both from within and from without.

' CHQARLES STEELE.

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