US293709A - Process of casting metals - Google Patents

Description

(No Model.) O. F. BRUSH.

1 PROCESS OF CASTING METALS. V No. 293.709. Patented Feb. 19, 1884.

PETERS, mlouuw mpher. Washingion. DJ:

IJNITED STATES PATENT OFFICE.

CHARLES F. BRUSH, OF CLEVELAND, OHIO.

PROCESS OF CASTING METALS.

SPECIFICATION forming part of Letters Patent No. 293,709, dated February 19, 1884.

' Application filed October 24, 1883. (No model.)

To all whom it may concern:

Be it known that I, CHARLES F. BRUSH, a citizen of the United States, residing at Cleveland, county of Guyahoga, State of Ohio, have invented or discovered a new and useful Improvement in the Process of Casting Metals; and I do hereby declare the following to-be a full, clear, concise, and exact description theremetal to flow as freely and fully as desired quired to fill minute parts of the mold is so small that it is chilled by contact with the sides of the mold-cavities before'they are entirely filled. Another fruitfulcause of defective castings is the dross and other impurities which are formed or which accumulate on the surface of the metal. As it is nearly impossible to entirely remove such impurities in ordiary modes of casting, they are liable to be carried sometimes into the mold with the good metal, and wherever they lodge they form holes or defective places.

The object of my invention is to remedy these and other defects in the presentmethods of casting, more particularly as regards the class or kind of articles referred to, and to produce such castings complete and sound, as near as may be, in all their parts, and free from holes or other defects; and my invention consists in the method substantially as hereinafter described and claimed.

In the drawing, A represents the walls of a suitable furnace. B represents an iron vessel for containing the molten lead, and Ca 5 jointed and divided mold, closedand submerged in the molten metal preparatory to executing the subsequent steps of the process.

The construction of the mold and mechanism for manipulating the mold are not herein shown or described, as they form thesubjectmatter of other applications of even date herewith.

In carrying out my process, I take a suitable jointed or divided mold, such as, bythe use of proper mechanism, &c., may be while closed immersed in a bath of molten metal, and opened and closed quickly while therein and quickly removed, and having heated it to the requisite temperature, which is somewhat below the melting-point of the metal to be cast, I apply to its inner surface a suitable lubricant, such as will prevent the casting from adhering to the mold. The mold is then tightly closed, in which condition it is dipped or immersed into a bath of the molten metal from which the casting is to be made, such bath" having a sufficient depth to submerge the mold therein. As soon as the-mold is thus submerged, its

jointed or divided parts are separated ormoved apart, so as to provide for a practically unimpeded flow of the molten metal along between the projecting parts which there may be in the contiguous inner faces of the mold, or along over the projecting parts on one or more faces. Preferably, I so make the mold that when thus opened or its parts are separated an inflow of metal takes place from all sides along the lines or planes of division; but this is not essential, as useful results will follow even if the Sc filling of the mold be done from one or two open sides or ends. In this regard the chief feature of importance is the separation of the opposite parts of the mold one from another, for the ready and rapid flow of the metal over the projecting parts of either or any mold-face, whereby the receiving capacity of the mold is increased over and above what it would be if the mold were kept closed,and the metal is quickly supplied, and at a good casting-heat readily and rapidly enters, or on the reclosk ing of the mold is pressed into the small cavi ties or interstices of the mold face or faces, so as to insure a good casting; and it is a still further characteristic feature or result of this method or process of casting that more metal is admitted between the walls of the mold than is essential for the formation of the casting, and hence I am never short of a sufficient quantity or supply; but so much as does not go into the casting to be made is excluded or I oo drawn out on the reelosing of the mold, which is done by suitable mechanism while the mold is still submerged, and ordinarily as soon as it is filled, and this latter work will usually occupy but the fractional part of a second. Themold is then withdrawn and opened and the casting removed, and as a result of the operation described it will be found that the metal has filled or flowed into the small interstices, or between the leaves or other proj ecting parts, and that a more perfect and complete casting has been produced than in such work has heretofore been attainable. Care must be taken that the mold, either in being artificially heated before submersion in the molten metal or while it is in use, be kept at atemperature below the melting-point of the metal to be casttherein, for otherwise the film or fin of metal inclosed between the meeting faces of the joints of the mold when the latter is reelosed would not solidify, and in such case some or all of the metal inclosed within the mold and not yet solidified would be liable to run or leak out when the mold is withdrawn from the bath, with the result of producing a defective casting; but the mold should be hot enough to avoid danger from a too rapid chilling of the metal as it flows in when the mold is opened, which, if it occurred, would be liable to prevent the proper flow of the metal into the small cavities or interstices at all points, particularly in a casting of considerable lateral size, and, still further, would interfere with the reelosing of the mold. By thus closing the mold and then submerging it in the bath I prevent any dross, slag, or other impurities which float on the surface of the molten metal from entering the mold; but as regards this feature of the submergence of the mold in the metal it is only necessary that the joints to be opened be so far or so completely beneath the surface of the metal as that no dross or other surface impurity shall flow in, or, if any does fiow in, the relatively large proportion of good clean metal which does flow in shall be so great that when the mold is reclosed the excess of metal then driven out or excluded shall wash. or drive out any dross or other impurity so admitted, with the result of a casting of good clean metal. The mold on being reclosed is withdrawn, opened, and the casting is removed in any suitable way, and the operation is repeated; and it maybe added that the work of submerging, opening, and closing and withdrawing the mold should be performed very rapidly, so that the mold will not become too highly heated by the metal of the bath.

In this description I have omitted all reference to the accessories commonly employed in casting operationssuch as a cavity in which to inclose metal to provide for shrinkageand such accessories may be added as the work may require; but these and other features of construction and operation of the mold and its operative mechanism, so far as they may involve invention, will form the subject-matter of other applications to be filed in due time; but as regards the opening and closing of the mold, it is not material whether the mold be made in two or more parts, nor whether such parts be so connected as to open and close by a hinge-joint or by a direct motion of one or more parts to and from one or more other parts.

Vhile I have up to this point described the closing of the mold before submcrgence as an element of the present process, it is still true that this feature may be dispensed with, particularly if the surface of the bath be kept clean or practically clean of dross or similar impurities, or it means be added for preventing the same, if present, from entering the mold to any injurious or deleterious extent. In such case the mold may be submerged while open, so that as its open sides are depressed beneath the surface of the bath the metal will fiow in, as above described. The mold should, however, be regulated as to temperature as above stated, should be immediately closed after proper submergcnee,

and promptly removed, as already set forth;

and this method of eastingnamely, by submergenee of a divided or jointed mold in a bath of molten metal in such manner that the opposite parts or cavity-walls thereof being separated the molten metal may flow freely therein, followed by a prompt' closing of the mold and its immediate removal from the bath-is included herein as apart of my present invention; and this process may be use-i fully employed in the making of castings generally, by which I mean without limitation as to shape, or without reference to the presence of projecting parts on the walls of the moldcavity; and in this connection it may be still further added that, in consequence of the admission in either case of more metal into the mold than is requisite for the formation of the casting therein, and of the exclusion of the excess on the reshutting of the mold, not onlyis the metal pressed into the cavities or interstices, but the outgoing stream of metal is cut off, so as to pack the joints by a film or fin of metal, which is solidified by the closing thereon of the meeting walls of the mold along the plane of the joint of the closing parts simultaneously with the completion of the casting by pressure or by the quantity of the metal itself; and this solidification of such film is effected in consequence of the fact already stated that the temperature of the mold is kept below the melting-point of the molten metal itself.

Vhat I. claim [herein as my invention is- 1. The herein-described method of casting metals,whicl1 consists in submerging a jointed or divided moldin abath of molten metal, a lowing the mold to fill while two or more of its opposite walls or parts are separate, and then closing the same while still submerged, substantially as set forth.

2. The herein-described method of casting metals, which consists in submerging a tightlyclosed jointed or divided mold in a bath of molten metal, separating the. opposite parts thereof, and reclosing the same while still submerged, substantially as set forth.

. 3. In the process of casting bythe submergence of a j ointed or divided mold in themolten metal, the combination of the following steps: first, the heating of the mold to a point above that at which the metal flowing therein on or after submergence would chill too rapidly, but

below the melting-point of such inflowing metal; second, submerging the mold in the molten metal; third, allowing the mold to 'fill 'while two ormore of its opposite parts are separated; fourth, closing the same while still submerged; and, fifth, withdrawing the same from the molten metal, substantially as set forth.

4. In the process of casting by submergence of a jointed or divided mold in the molten metal, the combination of the following steps: first, the heating of the mold, substantially as described; second,submergingthe closed mold, substantially as described; third, opening and filling it, substantially as described; fourth, reclosing the same, excluding surplus metal, and packing the joints'with chilled metal, substantially as described; and, fifth, withdrawing the same from the molten metal, substan- 3o tially as set forth.

5. In the process of casting by the submergenceof a jointed or divided mold in the molten metal, the process of simultaneously pressing the molten metal into the smaller 5 cavities of the mold, expressing the excess of metal, and packing the joint or joints of the reclosed mold by clamping the meeting walls of the mold onto and so chilling a film of metal between such walls on the closing movement 0 of the previously-separated parts of the mold while still submerged, substantially as set forth.

' 6. In the process of casting by the submergence of a jointed or divided mold in the molten metal, the method of packing the joint 45 or joints of the mold by closing the meeting I walls thereof on a film of the escaping metal CHARLES F. BRUSH.

Witnesses:

J N0. CRowELL, CHAS. H. DORER.

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