US2538656A - Molding flask and method of molding - Google Patents

Description

Jan. 16, 1951 K. T. RINDERLE MOLDING FLASK AND METHOD OF MOLDING 2 Sheets-Sheet 1 Filed May 17, 1947 INVENTOR. KARL T R/NDE/ELE.

ATTO FIVE.

K. T. RINDERLE MOLDING FLASK AND METHOD OF MOLDING Jan. 16, 1951 Filed May 17, 1947 2 Sheets-Sheet 2 Jfig.

W; INVENTOR. KQAL 7i R/NDEELE OMM QWAVZ ATTORNEYS.

Patented Jan. 16, 1951 FFICE MOLDING FLASK AND METHOD OF MOLDING Karl T. Rind'erle, Sandusky, Ghio, assignor to Incorporated, Sandusky, Ohio, a corporation of Ohio Application May 17, 1947, Serial No. 748,785

Brown Industries 15 Claims.

This invention relates; as indicated, to mo ding flasks and more particularly to a novel molding flask adaptedto be employed in a new and improved method of stack molding.

In the foundry industry it is conventional to employ two-part sand molds comprising the cope and drag which together define the mold cavity. When a large number of castings are to be produced it is often economical to form an upper mold cavity in the under face of a flask section and a corresponding lower cavity in the upper face of the same flask section. A number of such flasks may then be stacked one upon the other and the castings poured either individually or from a single riser. Obviously twice as many castings may be produced in this manner with a given number of flasks as when a separate pair of flasks is employed for each complete mold.

As indicated, however, this system of stack molding has only been practical in the past where a large number of castings are to be produced and a large outlay of money is justified. Special molding machines have been required and only the most skilled operators have been capable .of obtaining consistently satisfactory results due to the fact that each flask has had to be filled absolutely flush with both the upper and lower margins thereof in order to obtain a perfect meeting of the mating surfaces of the mold sections. This calls for perfect control of the mass of sand introduced into the'flask section before ramming as well as a perfectly adjusted molding machine. Perfect meeting of the mating surfaces is, of course, necessary to prevent escape of the molten metal, and a heavy pouring weight is ordinarily placed on top of the stack to hold the flasks in close engagement with each other. Since such flasks often warp or crack after a short period of use difliculty may be encountered in obtaining a perfectly tight stack even when great care has been taken to insure that the. flasks have been filled absolutely flush. Furthermore, individual flasks may be held apart by grains of sand or other forei n material between the same. It is; therefore, a primary object of my invention to provide a novel molding fla's'k particularly adapted for use in stackmolding whereby the foregoing difficulties may be avoided.

It is another obiect of my invention to provide a new method of stack molding which will permit the employment of conventional molding machines and which will not require the use of specially trained or skilled personnel.

A further object is to provide a moldin stack which may be handled as a unit except during mounted aligning pins 6 and l.

the molding operation and which will occupy a minimum amount of space when not in use.

Still another object is to provide such an improved flask which will safely hold the molded sand therein during transfer from the molding machine to the stack but from which such sand may be readily removed after casting. Other objects will become apparent as the following description proceeds.

To the accomplishment of the foregoing and related ends, said invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principle of the invention maybe employed.

In said annexed drawings:

Fig. l is a top plan view of one embodiment of my new improved molding flask;

Fig. 2 is a side elevational view of such flask;

Fig. 3 is an end elevational view of such flask;

Fig. l is a perspective view of such flask;

Fig. 5 is a vertical sectional view of a stack of my new flasks illustrating their arrangement when empty;

Fig. 6 is a vertical sectional view of a stack of such flasks showing the manner of their assembly preparatory to the casting operation; and

Fig. '7 is a diagrammatic elevational View of a molding machine showing the molding of a flask section employing my new improved flask.

Referring now more particularly to such drawlugs, and especially Figs. 1- inclusive, the flask of my invention may be of a variety of shapes, such as round, rectangular, or square, a square flask being here illustrated. In the embodiment shown in such figures my new flask comprises vertical upper side wall portions l, inwardly inclined portions 2, and lower portions 3, inwardly inclined to a lesser degree. A pair of box- like brackets 4 and 5 are attached to either side of such flask in the upper webs of which are Such pins may desirably be tapered slightly at-thei'r upper ends Referring now more particularly to Fig. 7, a flask is there shown supported on stripping pins I 2 and 13 (of which there will ordinarily be four) of a conventional molding machine M. The flask has been raised from the cope pattern !5 after forming the upper mold cavities [6 in the under.

side of the flask section, and the drag pattern I! carried by squeeze-head I8 has been raised to be swung aside after forming thelower mold cavities l9 in the upper side of the flask section. The operation is conventional except thatthe plate of drag pattern ii is dimensioned to fit within the inner margins of upper side wall portions l of the flask.

The lower mating surface 26 of each mold section is therefore flush and even with the lower margin of the flask but the upper mating surface 2| while perfectly parallel to surface 2% may vary in location along the vertical extent of side wall portion i Thus, even though somewhat different quantities of sand may be placed in the different flasks, such sand may always be compacted to the desired degree and perfect cavities and mating surfaces formed. The inward inclination of side wall portions 2 and '3 serves to hold the molded sand in place While the flask is being transported from the molding machine to stack and also permits the stacking of such flasks in telescoping or nesting relation, as shown in Fig. 6. The flasks are, of course, automatically aligned by means of pins '5 and 1 whereby perfect juxtaposition of mold cavities I6 and I9 is obtained. Since the lower margin of each flask rests directly upon the upper mating surface 2! of the sand in thenext subjacent flask a perfect joint is obtained despite the fact that the level of such upper mating surfaces may vary from flask to flask and will seldom be exactly even a with the upper lip I l of a flask.

When the heavy pouring weight is now placed upon the top of the stack, resting directly on the sand in the topmost flask, it is obvious that the weight thereof will be transmitted downwardly through the mating surfaces between each pair of flask. sections rather than directly from side wall to side wall of each succeeding flask as in conventional practice. The action of such weight is therefore much more positive and reliable in obtaining the desired result of insuring tight engagement of the respective mating surfaces.

The stack is then poured and after the metal has set for a sufficient time the whole stack is inverted as a unit and vibrated. This shakes out all of the sand and the castings flow freely from the stack since the side walls of each flask resemble an inverted funnel. Side stops it engage lips i i of the flasks (considering the stack of Fig. 5 as inverted), thereby preventing the flasks from wedging together. When the stack has thus automatically telescoped the empty stack may be transported as a unit backto the moldingmachine or may be set aside and stored where it will occupy a minimum of space as a result of the nesting of the flasks.

The fact that the walls of the flask incline inwardly, as above explained, does away with the necessity for the conventional sand strip or internal rib running around the bottom edge of the flask to hold the molded sand therein. As a re sult the flasks shake out clean much more readily. It will be seen from the foregoing that I have provided a novel molding flask and method of stack molding which is not only adapted for use with ordinary equipment but which produces results superior to that obtained in the past when 4 employing methods and equipment requiring a high degree of skill in their operation. It will, of course, be understood that my flask and method are adapted for use with various types of molding materials and the molding box or flask may be of metal, wood, or other desired materials. The chief advantages of my invention'are particularly realized, however, in the foundry where gray iron and the like are cast in sand molds.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims, or

the equivalent of such, be employed.

I therefore particularly point out and distinctly claim as my invention:

1. In a molding operation, the steps comprising forming cope and drag molds in each of a plurality of molding flasks, and then stacking such flasks with the lower margins of such flasks supported directly and entirely upon the respective mating surfaces of the drag molds.

2. In a method of stack molding, the steps of filling the flasks with sand even with the lower margins thereof but with the upper parting surfacesbelow the level of the flask upper wall margins and stacking such flasks with the lower margins thereof resting directly upon and entirely supported by the respective upper mating surfaces of the sand in the next subjacent flasks. r

3."In a molding operation, the steps which comprise placing molding sand within a molding flaskyinserting a plate carrying a drag pattern within the upper margin of such molding flask, thereby producing a mating surface lower than such upper margin, removing such plate and pattern, and placing another flask having a low er margin enclosing a cope mold directly upon and entirely supported by such upper mating surface of the sand in such first flask, the lower mating surface of the sand in such upper flask being flush with the lower margin of such flask.

4. In a method of stack molding, the steps of stacking the molding flasks with their lower margins enclosing the cope mold'resting direct- 1y upon and entirely supported by the upper mating surfaces of the sand in the next subjacent flasks, and placing a heavy pouring weight upon such stack the effect of which is thus transmitted down through the sand in such flasks.

5.'In a method of stack molding the steps of stacking molding flasks with their lower margins enclosing a cope mold resting directly upon and entirely supported by the upper mating surfaces of the sand in the next subjacent flasks,

and placing a heavy pouring weight directly upon the sand in the topmost flask of such stack, the effect of 'which is thus transmitted down through the sand in such flasks.

6. A molding flask and mold therein prepared for use in a stack molding operation, the mating surface of the drag being below'the upper margin of said flask and the mating surface of of such upper side wall portions, whereby one such flask may be partially telescopically received within another identically dimensioned 8. A stack molding flask having vertically disposed upper side wall portions, inwardly inclined intermediate side wall portions, and lower side wall portions inwardly inclined to a lesser degree, the inner lateral dimensions of said flask defined by said upper side Wall portions being greater than the corresponding outer lateral dimensions of said lower side Wall portions, whereby the lower portion of one such flask may be telescopically received within the upper portion of another identically dimensioned flask.

9. A molding flask having upper wall portions of greater lateral dimensions than the corre-- sponding lower wall portions thereof; said flask enclosing a sand mold even with the lower margins thereof but with the upper mating surface of said sand below the level of the flask upper wall margins.

10. A sand molding flask containing a cope mold, and a flask containing a drag mold, said cope flask resting directly upon the upper mating surface of the sand in said drag flask, and entirely supported thereby.

11. A stack of molding flasks with the lower outer marginal portion of each flask of lesser lateral dimensions than all corresponding inner lateral dimensions of the upper wall margin of the next subjacent flask.

12. A stack of molding flasks with the lower outer marginal portion of each flask of lesser lateral dimensions than all corresponding inner lateral dimensions of the upper wall margin of the next subjacent flask; and each of said flasks enclosing a sand mold having a mating surface even with the lower margin thereof, the lower margins of said flasks resting directly upon and entirely supported by the upper mating surfaces of such sand mold in the next subjacent flasks.

13. A stack of molding flasks with the lower marginal portion of each flask of sufiiciently lesser lateral dimensions than the corresponding inner lateral dimensions of the upper wall margin of the next subiacent flask that such lower marginal portion is telescopically received within such upper wall margin; and each of said flasks enclosing a sand mold even with the lower margin of the respective flask but with the upper mating surface of such mold below the level of the flask upper wall margin; the lower margin of each said flask resting directly upon the upper mating surface of the mold in' the next subjacent flask.

14. A stack of identical molding flasks, each flask having vertically disposed upper side wall portions, inwardly inclined intermediate side wall portions, and lower side wall portions inwardly inclined to a lesser degree, the lower margin of such lower side wall portions being of lesser outer lateral dimensions than all corresponding inner lateral dimensions of the upper margin of such upper side wall portions, and means on said flasks adapted to maintain alignment thereof.

15. A stack of molding flasks, each flask having vertically disposed upper side wall portions, inwardly inclined intermediate side wall portions, and lower side wall portions inwardly inclined to a lesser degree, the lower margin of such lower side wall portions being of lesser lateral dimensions than the corresponding inner lateral dimensions of the upper margin of such upper side wall portions, and each of said flasks enclosing a sand mold having a mating surface even with the lower margin thereof, the lower margins of said flasks resting directly upon the upper mating surfaces of such sand mold in the next subjacent flasks, and means on said flasks adapted to maintain alignment thereof.

KARL T. RINDERLE.

REFERENCES CITED The following references are of recordin the file of this patent:

UNITED STATES PATENTS Number Name Date 127,398 Williamson May 28, 1872 652,129 Michaelson June 19, 1900 710,331 Mills Sept. 30, 1902 738,278 Beckwith Sept. 8, 1903 738,279 Beckwith Sept. 8, 1903 1,119,418 Ford Dec. 1, 1914 1,773,732 Hines Aug. 26, 1930 1,873,176 Barr Aug. 23, 1932 1,992,677 Sorensen Feb. 26, 1935 FOREIGN PATENTS Number Country Date 864,225 Germany Nov. 18, 1922

Images