US4803A

US4803A - Improvement in making molds for castings

Info

Publication number: US4803A
Authority: US
Publication date: 1846-10-07
Anticipated expiration: 1863-10-07

Description

`UNITED STATES l PATENT OrmesC FRANOISAN. STILL, OF BUFFALO, NEW YORK.

Speciiication forming part of Letters Patent No. 4,803. dated October 7, 1841i.

To all whom it nil/wy concern,.-

Beit known that I, FRANCIS N. STILL, of

Buffalo, in the county of Erie and State of New York, have invented a new and Improved Method of Molding for Castings; and I hereby declare that the following is a full and exact description. y

The nature of myinvention consistsin using two patterns for one casting, and having those patterns placed with the reverse sides up,and made stationary in two separate Ilasks filled with plast-erot'paris. My object in using two patterns is that I may mold from concave and convex patterns, such as cannot be divided or molded from a plate. My object in using the two asks of plaster-of-paris is that I may get t'wo concave and convex lsurfaces to lit each other perfectly, and at the same time lit the particular shape of the patterns, so that when atlask of sand is filled upon each of them, taken off, and closed together, it will form a perfect mold from said patterns. I

To enable others skilled in the art to make and use my invention, I will proceedto de! scribe its construction and operation.

The two frames A and B in the accompanying drawings, are intended to represent two separate flasks, which are made to fit each other perfectly. I then ll the flask A with a putty made OI'plaster-Of-paris, as is seen at C, and place in one or more patterns, as I think i it most convenient, with a part of the pattern raised above the putty, as is seen at D. After the putty becomes set and hard, I put on a coat of oil to prevent the green putty from pression of the pattern D.

sticking to it. I then take the flask B, place it upon the ask A, and till it with a green putty, press it down and let it remain until it be comes set and hard. I then take it off, having a perfect fit of the two iiasks of plasterot paris, as is seen at C and E, and also an im- Ithen take my second patternand place it in the impression taken from the pattern D, as is seen at f. Thisy done, my patterns are complete andready for use. I now use the two flasks containing the plaster-ciparis and patterns as a stationary die, upon which I strike the molds in sand for castings.' For example, I take a set of flasks,

as is common in molding, and fit them to the asks A and B, fill them with sank, take them off, close them together, and this forms a perfeet mold of the patterns contained in the two asks of plaster-of-paris.

I do not claim molding from plain patterns, such as can be divided and molded from eachY half, nor from such as can be molded in connection with a plate.

What I claim as myinvention, and desireto secure by Letters Patent, is- A Making the second pattern or patterns by taking an impression of the rst upon plasterof-paris or other similar. substance, and placing duplicate patterns in the cavities made by the patterns of the first, substantially as herein described.

FRANCIS N. STILL. Vtnesses:

J. M. THAYER, Z. O. RoBBINs.