US1551590A - Centrifugal casting - Google Patents

Description

Sept. 1-, 1925;

R. sTREsAu GEN TRIFUGAL CASTING Filed July 19 1923 INVENTOR.

fif c/mrd \Yfresau, WATTORNEYS.

'thesamewithasu Patented Se t 1-, j UNITED- STATES.

mcmnn srnnsau, or wauwarosa, wrscousm, ASSIGNOB To a. o. snrrn conrona- 1,551,590 PATENT- oFFicn.

, I T1011, 01 IILWAUKEE, WISCONSIN, A CORPORATION 01 NEW YORK.

cam-nirvana cas'rmo.

. Application fled my 1a, 1923. Serial no. 055,495.

To all whom it may concern:

Be 't known that I, "RICHARD STRESAU, a citizen of the United States, and a' resident of the city of Wauwatosa,in the county of .Milwaukee and State of Wisconsin, have invented certain new and useful Improvements in Centrifugal Castings; and I do declare the followin to be a clear, exact,-and

complete 'descri tion thereof, such as'will' enable others skilled in the art to which the invention pertains tense and practice the same.

My invention relates in general to the 1'5- casting of tubular articles, and in particular to pi couplings, by the centrifugal process,

m w 'ch a measured quantity 'of.molten'-' metal is poured into a cylindrical mold during the rotation of the latter. By virtue'of the rotation of the mold up'on itslongitudir nal axis at a'high :rate of speed, the metal is caused by centrifugal force to flow evenly against the moldin surface so as to cover stantially'uniform den:

sity and reduce a 'hollow castin the w of w 'ch are of uniform thic ess th hout.

'- themodw Al ough this manner ofcasting is a simle matterand is easily accomplished, it is ound that the casting m chilling sometimes sticks to the steel mold, requiring an exnditure of time in removing the casting m the mold as well as incurring an mterruption of the casting operations due to such exigency. s

My present inventioncomprises theprovision of a means for remedyin the ad- ,yerse conditions referred to, an

which I am enabled to practice centrifugal through casting in amanner in which all liability of the casting to stick to the mold is eliminated, and to permit discharge of the casting fromithout loss of time or interrup 'tion of the casting. operation as a continuous be a mold prior to each casting one.

This result I achieve'by in the 7 cast linformed as a thin sheet-o metal havi su tially the character and pro es 0 the metal being cast. The lining eet conforms closely to and cmnpletely coversthe curved molding surface, andjmay or may not lining will be i 111ml, mold-during-the of the latter, and

1to to the casting operation.

provided wit I rapi of which the-molten as the latter is introduced into the be incorporated as an integral part of the casting; But the low temperature existing between the contiguous surfaces of the mold and the lining will act as a chill to overcome any tendency whichthe casting might have to stick to the mold. Y

Although the lining is fused into the casting, the finished exterior of the rolled sheet from which the lining is formed is preserved practically in its primary state, so

that a much better finish is imparted to' the outer surface of the casting, in that the same in carrying out my invention, and will conclude with claims definingthe novelty of the latter.

In the drawings: I) M Figure 1 is a lo itudinal sectional view through the vertica axis of a water-cooled centrifugal casting machine, built in 'accordance with my invention, and preparag. 2 is a vertical sectional view of the machine shown in Fig. 1, on a l 1ne transverse toithe' axis of the mold, and taken at any point between the ends of the mold.

Referring to .the drawing, the numeral indicates the cylindrical hard metal mold of a centrifugal casting machine designed for use in castm tubular articles. The mold is iheads 11 and 12 having journals 13 and 14', which are mounted for rotation in bearings 15 and 16. The journal15 is rovided with driven means, as a belt pu e 17, through which a movement of rotation is imparted to the mold 10. The journal 16 is hollow and open from end to end, so that the molten metal may be introduced into the mold through the funnel trough 18, the. discharging end throu 'h the hollow journal and-m'to the mo d.' The funnel or trou' h may be supported in relatively 1 fix positionuponthe bearing 16 by means of the bracket 19, or it ma be independently described, the arrangement is quite usual. It

will increase the capacity for production by the apparatus to provide the mold with a concentrically arranged covering 20, spaced from the mold to constitute a water jacket,

so that Water may circulate through the space 21 and effect reduction of the temperatures within the molds.

But in the absence of any provision of cooling means, and even when used, it sometimes occurs that the casting will stick tothe mold, and can be dislodged therefrom only by an expenditure of time and labor, With a consequent unnecessary interruption and delay in casting as .a-continuous operation.

My invention obviates these difiiculties and delays. In achieving its purposes, I line the'mold with a thin sheetof metal having the properties of the metal which is being cast. The lining occupies the'length of the mold and is in the form of a tube 22, either seamed or not at the meeting edges 23 of the sheet out of which it is formed, and bears a snug contact with the whole of the inside surface of the mold.

When ready for casting the mold is lined as described and rapid rotation imparted thereto. Molten metal in a measured uantity is introduced into the mold, and qulckly distributes itself evenly over the interior surface of the lining, due to centrifugal force, with the result that a casting uniform in the density and thickness of its tubular wall is produced. The contact of the molten' metal with the lining fuses the latter into such a state that it becomes anintegral part of the casting, and loses its character as a shell in the amalgamation which takes place.

Although the fusion of the linin is complete, the casting will not stick to t e mold, due to the lower temperature created by the contact of the surfaces of the hard metal mold and the lining, whereby a chilling effect is produced in the area of such contact.

The proportions of the casting are indicated by the broken lines in the drawing.

The practice of my invention has enabled me to produce a better finish upon the outer surface of the casting, inasmuch as the original surface of the rolled sheet from which the lining is shaped is preserved in much of its entirety, and the surface cracks usually formed upon centrifugal castings are obviated.

specifically application Serial N 0. 18,229, filed by me on March 25, 1925.

Having'thus described my invention, what I claim and desire to secure by Letters Patent of the United States, is:

1. The process of casting a pipe couplin which comprises the steps of lining a mold with a thin sheet of metal, introducing into the mold during the periods of rotation of the latter a quantity of molten metal, and fusing and amalgamating the lining into a finished integral exterior surface of the tubular casting free from cracks.

2. The process of casting a pipe coupling which comprises the steps of lining a rotatable mold with a thin sheet of metal, intro ducing into the rotating mold a quantity of molten metal in the form of a layer ofuniform thickness, and fusing and amalgamating the lining as an integral part of the casting by the centrifugal contact of the molten metal therewith, to constitute a finished exterior surface for the casting free from cracks. f H 1.

3. In centri uga castin i e cou in 's the method of prevla nting 51 Easting frd m stickin a metal introduction of molten metal to form a chill between the surface of the moldand the molten metal, and fusing the lining in the contact of the molten metal therewith so as to constitute an integral exterior surface for the casting free from cracks.

In testimony whereof, I have signed my name at-Milwaukee, this 17th day of July,

- R. STRESAU.

mold with sheet metal prior to the into the mold,

to the mold, which consists in lining

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