US465035A - Mandrel for casting chilled pipes - Google Patents

Description

(No Model.)

W. G. WESTAWAY. MANDREL FOR CASTING GHILLED PIPES.

No. 465,035. Patented Dec. 15,1891.

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UNITED STATES PATENT OFFICE.

\VALTER C. \VESTA\VAY, OF DEGORAH, IO\VA.

MANDREL FOR CASTlNG CHILLED PIPES.

SPECIFICATION forming part of Letters Patent No. 465,035, dated December 15, 1891. Application filed February 19,1891. Serial No. 382,128. (No model.)

To all whom it may concern.-

Be it known that I, WALTE (J; WEs'rAwAY, a citizen of the United States of America, residing at Decorah, in the county of I'Vinneshiek, in the State of Iowa, have invented certain new and useful Improvements in Mandrels for Casting Chilled Pipes, of which the following is a specification.

Referring to the accompanying drawings, wherein like reference-letters indicate like parts, Figure 1 is a side elevation, and .Fig. 2 a section in line 2 2 of Fig. 1.

For many purposes in theindustrial arts it is desirable to use metal pipes of smooth cylindrical or substantially cylindrical bore, chilled on the inside. To cast such a pipe, it is necessary to cast the metal around a cent-ral mandrel or chill. It has, however, been found in practice that the contraction of the chilling metal against the mandrel strains the walls of the pipe, and the mandrel then expands by the heat communicated to it from the pipe, increasing the strain to such an extent as often to burst the pipe and always to render it weak and practically worthless unless cast very thick and heavy, and it is difficult to remove the mandrel from the pipe after the casting has been made.

The object of my invention is to so improve the construction and operation of the mandrel or chill as to obviate the difficulties referred to and the invention consists in the improved mandrel or chill herein described.

In the drawings, Aindicates a hollow mandrel, with its bore 13 somewhat eccentric to its periphery, and having from end to end at its thinner side a longitudinal division or opening, tapering outward in cross-section, and filled up when in use with a strip or key 0, of corresponding form. In preparing the mandrel for use the key 0 is inserted and held in place by anysuit-able elastic or yielding material-for example, by sand tamped in the bore of the mandrel, as indicated in Fig. .3. IVith such a mandrel the contracting metal chilling around it forces the wedgeshaped key slightly inward against the resistance of the material in the bore, and at the same time by compressing the walls A it springs or bends them inward at their divided side tightly against the key, the eccentric bore causing the flexure to distribute itself with substantial uniformity throughout the entire periphery of the wall A, and thus preserve the cylindrical form of the casting. l/Vhen the casting is completed, the sand is removed, the key dislodged inwardly, and the mandrel is then readily loosened and detached from the pipe. Instead of the metal key, the sand itself may be used as a key by tampi ng it tightly into the dividing-space and smoothing and polishing the outer surface, in which case the dividing-space need not necessarily be made wedge shapein crosssection.

By the word pipes as used herein I mean any tubular form, long or short, including wheel-hubs, journal-boxes, and similar articles, as well as the articles commercially known as pipes.

I find it easy,with mandrels or chills of the kind above described, to cast metal pipes of extreme thinness, and yet of great strength, with their inner surfaces chilled, smooth, and cylindrical, requiring no further finish for ordinary uses, and with their outer surfaces unchilled and of great tensile strength. The interior surface of the pipe takes its form instantly upon the first contact of the hot metal with the cold mandrel, and the latter the-n supports it sufficiently to prevent any alteration of such form, although yielding inwardly sufliciently to prevent its own expansion from uudulystraining the surrounding plpe.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. The improved mandrel or chill for easting purposes herein described, consisting of an eccentrically-borcd metal tube divided longitudinally at one side, with a metallic key interposed in the dividing-space, and with the center provided with a yielding material to hold the key in position, substantially as herein set forth.

2. The improved mandrel or chill for casting purposes herein described, consisting of an eccentrically-bored tube divided by a longitudinal slot at the thinner side, and a filling for said bore and slot arranged to yield as the casting cools, substantially as described.

3. The improved mandrel or thill for east- 5 ing purposes herein described, consisting of an eccentricall'y-bored tube divided by alongitudinal slot widening toward the center of the tube, a key fitting said slot and havinga broad head bearing against the edges of the inner surface of the tube, and a yielding fill- [0 ing for the bore to hold said key in place, substantially as described.

WVALTER (l WESTAWVAY. WVitnesses:

W. M. HILL, FRANCIS E. DRESSER.

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