US443687A - Method of forming molds - Google Patents

Description

(No Model.)

F. 0. STURGES. METHOD 01- FORMING MOLDS.-

Patented Dec. 30, 1890.

R O T N E V N WlTNESSES w: NORRIS vans cm, wuTourrlow, wAsMmm'nu, o. c.

UNITED STATES Y ATENT OFFICE.

FRANK c. STURGES, or WILKES-BARRE, PENNSYLVANIA, AssIcNoR TO THE WILKEs-BARRE MOLDING MACHINE COMPANY, or PENNSYLVANIA.

METHOD OF FORMING MOLDS.

SPECIFICATION forming part of Letters Patent No. 443,687, dated December 30, 1890.

Application filed February "7,1890. Serial No. 839,565- (No model) other chills are usually employed.

In Letters Patent of the United States No. 360,086, dated March 29, 1887No. 360,119, dated March 29, 1887-No. 371,820, dated October 18, 1887No. 408,57 9, dated August 6,

2o 1889-and No. 409,667, dated August 27,1889, are shown described and claimed sundry methods of and apparatus for forming molds for molding car wheels, in the practice of which methods and the operation of which apparatus, a pattern is pressed into the sand, making an imprint, which pattern, by the same operation, rams or compresses the sand to the required density.

It has been found difficult in operating the mechanism and in practicing the inventions embraced in the foregoing patents, to bring the pattern to the precise level of the flask wall, so that the chill, used in the casting of a car wheel, could take its bearing on the rim 3 5 of the flask, and thus hold the mold firmly in place when it was closed and clamped to receive the metal; thus if the pattern did not descend to its proper place, the strain on the mold when closed and clamped, elfected a compression of the sand under and over the chill and thus caused an irregular and defective casting; again if the pattern descended below the proper point, the chill, taking its bearing on the edge of the flask, the parts of the mold, the cope, drag, and chill, were prevented from fitting closely together, whereby the molten metal was allowed to escape. To overcome these objections the practice has been to allow the pattern, which is a trifle smaller than the flask, to descend into the flask a short distance, and to place the chill on the compressed sand inside the Wall of the flask. This practice in a measure overcame said objections, but was itself objectionable in that the pattern, being of only slightly less diameter than the inner Wall of the flask, was liable, when in the act of descending into the flask, if for any reason the flask was not accurately centered, to come into contact with the walls of the flask and thus occasion a breakage of a pattern or of some portion of the machinery. When the pattern was withdrawn from the flask loose particles of sand, caught between it and the flask, would fall upon the mold and thus necessitate a certain amount of hand labor in order to perfect the mold and put it in proper condition for closing and receiving the metal; and, finally, the chill, taking its entire bearing on the sand, was liable when the mold was subjected to extreme pressure, to yield and thus cause an imperfect casting. I overcome all of these objections by adjusting the height of the flask wall, and the point to'which the pattern shall descend so that 7 5 the pattern will under no circumstances descend down to the flask but to a point a short distance above it. I provide a flat surface on the rim of the flask and cause to be distributed on it, by suitable means, a sufficient quantity of sand, and I extend the pattern so that it will overlap the outer wall of the flask, with the result that in the descent ofthe pattern the sand on the rim of the flask is compressed to a great degree of hardness. On the compressed sand on the rim of the flask the chill finds a firm and rigid seat which will not yield when the mold is closed and clamped; no hand labor is required to perfect the mold, and there is no 0 danger of breakage by reason of the pattern striking the flask.

In the drawings, Figure 1 is a central sectional elevation of a complete mold provided with a chill, and containing a casting of a double plate car wheel, which mold is of the character shown and described in United States Letters Patent No. 360,086, granted March 29, 1887, to Joseph J. Oarr for method of molding car wheels. Fig. 2 is a central 10o sectional elevation of a flask in which the sand has been distributed in approximately the form into which it is to be subsequently compacted by the pattern. Fig. 3 is a similar View of the same showing a sweep in operation upon said sand. Fig". i is a similar View of the same showing a pattern in place upon the sand, and Fig. 5 is a central sectional elevation of the cope and drag flasks of a mold, which mold embodies my invention and illustrates the relationship which the chill bears to it when its parts are placed together, and shows in place in the mold a completed casting of a double plate ear wheel.

Similar letters of reference indicate corresponding parts.

Referring first to Fig. l itwill be seen thatthe sand contained in each flask is, as to its marginal portion between the matrix proper and the wall of the flask, flush or level with the rim of the flask wall, and that the chill bears against the rim of each of said flasks. The molds of this figure are of the character heretofore in use, and hcreinbefore referred to.

In forming the mold according to the method which is the subject of my present application, I charge a walled flask with the sand or other molding material, extend a portion of the sand or molding material to and over the surface of the top of the wall of the flask, and fashion the sand contained in the body of the flask with more orless accuracy into the form into which the sand is to be ultimately compressed; I then occasion the descent of a pattern of sul'liciei'it area to extend to the outer circumference of the flask whereby the sand contained in the flask is compressed and formed into the desired ultimate shape, and the sand on the top of the flask wall is compressed to the required density to form the chill seat.

The following are the details of the operation thus briefly outlined:

The flask, A, in Fig. 2 is supplied with a quantity of sand, B, and said sand is distributed in any preferred manner within said flask to form which is, as stated, approximately that of the final desired form. A portion of said sand covers'the edge of the wall a, as shown at b.

In Fig. 3 is shown a sweep C, consisting of a rigid arm 0, and a roller, 0, of corresponding outline to the arm, both designed to be mounted upon a vertical rotatable shaft,- both of the usual and general construction and mode of operation,and both of sufficient length to extend over and therefore to operate upon the sand b upon the rim to, as well as upon the sand in the interior of the flask.

In Fig. at is shown the flask A and its con tained sand B, and also a pattern D, of diameter sufficient to extend to the outer circumference of the flask, and therefore to operate upon the sand 1) upon the wall a as well as upon the sand contained in the flask,- which pattern is shown as down in place upon the sand. The position which said pattern D is shown in the drawings as occupying, is the lowest which it is designed to reach, and the sand beneath it therefore is in the form which I herein term its ultimate form and in condition to be used in molding a wheel.

In Fig. 5 is shown a mold formed by the practice of my method, itbeing shown as holding between its cope and drag a chill E,Whi1e in the matrix is represented a cast car-wheel F.

I do not herein seek to cover the mold above described as it forms the subject of a separate application for Letters Patent tiled in the Patent Otlice February 7, 1800, as Serial No. 339,561.

Ilaving thus described my invention, I

' claim l. The method of forming a mold for east ing ear wheels, which consists in charging a walled flask with sand in which the matrix is to he formed,and in extending the sand of the mold to and over the surface of the top of the wall or rim of the flask, and in then causing a pattern to descend upon both the sand in the body of the flask and the sand upon the top of the wall of the flask, as specified.

53. The m thod of forming a mold for easting car wheels, which consists in charging a walled flask with sand in which the matrix is to he formed, and in extending the sand of the mold to and over the surface of the top of the wall or rim of the flask, and in then causing a pattern, the central portion of which is adapted to form the matrix of the wheel in the sand of the mold and the peripheral portion of which is adapted to form the seat for the chill on the sand above the rim of the flask and in the sand in that portion of the flask which is adjacent to its Wall, to descend to form said matrix and to form said seat for the chill, as specified.

In testimony that I claim the foregoing as myinvention I have hereunto signed myname this 27th day of January, A. D. 1800.

EDWARD E. IIoY'r, ALEXANDER Pa'rrnason.

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