US 304976 A
Description (OCR text may contain errors)
UNTTED STATES PATENT OFFICE..
ROBERT XV. TRAYLOR, OF RICHMOND, VIRGINIA.
MOLD FOR CASTING.
.CPECIFICATION forming partv of Letters Patent No. 304,976, dated September 9, 1884.
Application filed January 10, 1884.
To all whom, it may concern:
Beit known that I, ROBERT WV. TRAYLOR, acitizen of the United States, residing at Richmond, in the county of Henrico and State of Virginia, have invented certain new and useful Improvements in Molds for Casting, of which the following is a specification.
This invention relates to molds for castings, and has for its object the construction of a mold of such nature that it will not require to be renewed or remade each time a casting is made, and will at the same time produce castings free from grit and sand, and in a neater and smoother condition, thereby edecting a saving of time, labor, and the wear of tools now required for finishing.
My invention consists of a mold the whole or a part of whose matrix-cavity or moldingsurface is composed of mica.
To a full understanding of my invention reference should be had to the accompanying drawings, wherein I have illustrated the two halves of' lmy improved mold in perspective, the mold being shown as opened to expose the molding-surface.
Corresponding parts are designated by the same reference-letters.
The letter A refers to a casing or frame of any suitable size or form. This frame may be the ordinary well-known molders flask, or it may be specially constructed as to form, dimensions,and strength. Theframeorframcs A are filled with sheets or pieces of mica, B, compressed face to face against each other,
and preferably placed upright on their edges and at right angles to the sides of the frames. The sheets of mica B should be so tightly compressed as to prevent molten metal from running between the sheets, and to permit of the body of the mica to be cnt or dressed -to the desired configuration to form the matrix or molding-surface. Under suitable compression the exposed edges of the sheets or pieces of mica are capable of receiving a polish that results in rendering the surface of the meta-l cast in such a mold so smooth as to require no dressing to prepare it for use, `and at the same time t-he gases arising from the metal while in amolten state readily escape through the inierstiees between the sheets. A cavity, C, oi' suitable form, is out into the body of the mica (No model.)
in one or both of the halves of the flask, and the edges of the sheets around the cavity are cut or trimmed down iiush with the edges of the flasks or frames to cause the two masses of mica to make a close joint.
In making castings requiring a matrix-cavity in each of thehalves ofthe mold, I forma half gate-hole at the top of each frame or flask, and form a groove, c, extending from the matrix-cavities C to the gate-hole, to permit of the pouring of metal into the matrix-cavity; but in casting metal ornaments having a plane surface upon one sideI contemplate using a half-mold of mica to form the exposed face of the cast ornament and a half-mold of sand or other material for the plane surface of such ornamentl In this instance the gate hole couldf'be formed in the sand half of the mold.
I wish it understood that I do not conne myself to forming the matrix-cavity after the mica has been compressed in the frames, for when the shape of the castings desired is not much varied in its lines, angles, and curves the sheets or pieces of mica may be cut into the needed shapes before they are so compressed. N or do I confine myself to sheets 0r pieces of mica placed at right angles to the sides of the frame, for they may be arranged parallel with said sides; or, as shown in the drawings, some of the sheets may be arranged parallel with the sides of the frame and others parallel with the ends thereof; or they may be arranged diagonally with respect to said sides and ends. Nor do I confine myself to the exact form of mold illustrated in the accompanying drawings, as the advantage derived from forming the whole or a part of the molding-surface of mica is specially applicable to ingot-lnolds, and I regard such molds so constructed as within the scope of my invention.
I have represented in the drawings a mold shaped to cast the shell of a globe-valve, the mold being made in two halves, each having a suitably-shaped cavity; but it is obvious that in some instances one half of the mold will require to be made with a cavity and the other half with a projection, as in casting a concave-convex body.
Although I have throughout this specification referred to the molds as being formed of sheets or pieces of mica compressed to form a solid body, it is apparent that a solid block of mica may be used instead.
I ain aware that it has heretofore been proposed to line a mold with mieaeeous rock; but this I do not claim.
It will he seen. that by my invention I Vprovide a niold that is, so far as the operation of casting is concerned7 practically indestructi` ble, and that the mold may be used repeatedly without any renewal or reworking ofthe sui'- face which gives eoniguration to the casting.
That I claim as my invention, and desire to secure by Letters Patent, is
l. A mold Al'or casting metals, having the whole or part of its matrix-cavity or moldingsurface composed of mica7 substantially as described.
2. A nlold for casting metals, having its matrix-cavity or niolding-surface composed Wholly or in part of compressed sheets 0r pieces of mica, substantially as specified.
In testimony whereof I afx my signature in presence of two witnesses.
ROBERT IV. TRAYLOR.
C. V. MEREDITH, J'. I). COCHE.