US254521A - washburn - Google Patents

Description

(No Model.) L. W. WASHBURN MOLD POB. CASTING- GAR WHEELS. I No. 254,521. Patented Mar. 7,1882.

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UNITED STATES PATENT OFFICE.

LU'CIUS W". WASHBU'RN, BOSTON, MASSACHUSETTS.

MOLD I'TOR CASTING CAR-WH EELS.

SPECIFICATION forming part of Letters Patent No. 254,521, dated March 7, 1882.

Application filed January 9, 1882, (No model.) i

To all whom it may concern l Beit known that I, LUoIUs W..WAsnBURN, of Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Molds for Gastin g Car-Wheelsof which the following is a speci.:v lisationl The object of my invention is vto proridea the central or body portion being castfrom a soft metaly or common iron, and then, the mold being changed quickly, the tire is cast around the same from decarbonized; iron or steel,which. issusceptible of receiving a very hard chill.

It is found somewhat difficult tofcast wheels from4 two metals poured at different times into the same mold, on account of the time required to. make the necessary changes after thetirst metal cast has become partially crystallized or cooled sumciently so as to permit of the re-v moval of the necessary copes and stop-rings from the mold and the substitution of the ex. tra cope and chill-ring as heretofore employed, such changes requiring sufficient time to intervene to allow the first metal cast to cool toomuch before the second metal can be cast therein.V Thus to vform a perfect union of the two metals cannot at all times be relied upon,` thereby occasioning great loss of labor and material,.as it is very important in the construction of this class of car-wheels that the two metals cast should form a perfect vunion with each other. Molds as heretofore constructed for this purpose have not only been very expensive on account of the closely-fitting joints required, but on account of the unequal expansion of the two rings of metal heretofore employed in molds of this kind, either the one expanding so as to burst the other or leaving au open space between the two, so as to permit the cast metal to enter therein, thus destroying either the mold or spoiling the wheel cast. I am enabled by aid of my improved molds to fully overcome these and other objections 5 and my invention consists in the novel .construction, combination, and arrangement of certain parts of the mold, as hereinafter more fully described, and set forth in the claim.

Figure 1 is a perspective view of a mold constructed according to my invention adapted to form the cast central body portion of -a car-wheel. Fig. 2.is avertical central sectionv of the same; with that portionof the car-wheel; Fig. 3 is a similar view of the` i moldt complete with the car-wheel and its: lti1,e, y cast therein. the chill-ring .used-in casting they tire. is a similar view ofthe extra cope usedin cast-,1 ing the tire.

mold for casting car-wheels from two metals,

cast therein.

Fig. 4. is ak perspective viewof A represents the lower portion ofthe mold,

1 upon which rests the horizontal flange B of the metallic ring G, the interior face of which in. l clin es inwardly, being tapering or conical from. the bottom upwardv to the shoulder D, which.

serves toform a face or true surface on the rimy of the wheel when cast, which projects inwardly about the distance designed for the.

thicknessof tbe rim of the central or body port tion, E, `of the wheel, the periphery thereof be,- ing cast against the inner face, C, ot' this stop;y rin g, theupper portion or projection, F,ofw,hicl1l4 passing through or formed upon thelugsLexl j tending horizontally from theouter peripheryy of the said base portion A, and fitting within corresponding holes formed inthe lugs extending outward from the flan ge B of the said stopf. ri-n g, the upper portion, F, of which is secured to theends of the arms ofthe cope G by horizontal pins H passing through'said portion F and intocorresponding holes in the ends of the. said arms of the cope G, whereby it isretained in vposition while the metal is being cast into.- the mold thus formed.

The metal being poured through the sprueholes near the center of the cope G forms the center or-body portion, E, of the wheel being cast from soft iron, as heretofore. Now, as soon as the said center or body portion, E, of the wheel has been cast and sufficiently cooled as to set at its periphery, which contacts with the interior face of the lower portion, G, of the said stop-rin g, the said horizontal pins H being withdrawn, the stop-ring B C F is lifted upward and removed from the said portion A, leaving the central cope, Gr, in place or position undisturbed, and the sand therein resting upon the said central body portion, E, just cast, and by which it is supported. Now, a second metallic chill-rin g, K, (shown in Fig. 4,) of

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larger interior diameter than the lower portion, C, of the stop-ring removed, is instantly substituted therefor, as shown in Fig. 3, whereby the desired space is left between the interior of the said chill-ring K and the periphery of the body E just cast, which serves as or forms a niold for the steel tire P, au extra cope, L, (shown in Figs. 3 and 5,) of larger diameter than the cope G, and adapted to be placed on the mold with the said chill-rin g K, upon which it rests. Decarbonized iron or steel is then poured through the sprue-holes s, formed through they said cope L, so as to contact with the upper outer corner or periphery of the said rim of the central body portion, E, just cast, and by its'greater heat remelt the said partially-cooled periphery, so as to mingle or unite therewith so perfectly as to become, when cooled, one continuous casting throughout, the soft-iron central body portion' and the steel or decarbonized-iron tire having` a hard chilled periphery or tread. By means of the construstion ofthe said stop-ring B F C in one continuous piece, as shown, a very considerable expense is saved, and the time intervening between tbe first and second casting of the two metals is materially reduced, whereby a more thorough and perfect union of the same is obtained. s

I am well aware that heretofore stop-rings have been made in sections, and having an internal circumferential groove into which the cast metal of the body of the wheel would enter, thus requiring the stop-ring to be removed in'pieces, first horizontally within the mold, then raised up therefrom vertically, consuming so much time that the cast metal first poured would become too cool to be eEectually remelted by the casting of the second metal or tire, thus causing great loss by imperfect union of the two metals cast at different times, as the most rapid changes of the mold between the two castings of metals are required to obtain a complete mingling or union of the tire with the body previously cast.

I am also aware that heretofore a mold has been constructed for casting car-wheels from two metals cast into the same mold by the employment of a stop-ring constructed so as to form a groove in the periphery of the body first cast. Therein the stop-ring had to be formed in sections and be removed from the same, first horizontally, then lifted vertically from the mold before the casting of the second metal, wherein the time necessary to malte the changes required between the casting of the two metals was so great that the first metal cast would become crystallized and so cold that the second metal cast would not remelt it. Consequently cold shots77 were formed instead of a union of the two metals, as is produced by my invention.

I am also aware that heretofore these defects have been sought to be removed, and for such purpose thestop-ringandcopehavebeen formed in two separate pieces of metal, the coperim being turned off true at its periphery and f1tted outside of the metal stop-ring beneath, thereby requiring nicety of iittin g and adjustment of the two parts when placed together; but when the mold is so constructed the great amount of heat transmitted from the first metal cast against the inner face of the stop ring would cause it to expand so much faster than the cool metal cope-rim extending partially outside of the said stopring that such unequal expansion between the two wouldserve to break the outside cope-rim, and thereby destroy the wheel being cast and render the operation impracticable. My invention fully overcomes these defects, as the cope-rim and stop-ring are formed of one continuous piece of casting or metal, and thereby caused to expand uniformly or equally throughout.

Having thus described my invention, what I claim is The combination, with the base A and cope G of the mold, of the stopring consisting of the horizontal iiange B and internal incline faces, F and G, united by the horizontal face or shoulder D, all being formed of one continuous piece of metal, substantially as shown and described, as and for thepurposes set forth.

LUCIUS W. WASHBURN.

"Witnesses:

SYLVENUs WALKER, H. G. M ANNING.

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