US7915A - Improvement in metal or second patterns for castings - Google Patents

Description

- UNITED 4STATES i PATENT Clinics.

l FRANCIS n. srILuon NEW Y'ORK,N.Y,

lMPRovEMENTlN METALOR SECOND :5A"r1-lames FOR CASTINGS.

2'Specification forniingpnrt of Letters PatentNO. 7.915. dated' January 28.1851;

ToaZZ whom tm/ay concern,.- l

Beit known that I, FRANCIS N. STILI., of the city, lycoiinty, and VState of New Yo`x'k,l1aveA inventedzin-Improvement inthe Method of Castings; and I do hereby'deelare that the-l'ol- Ilowing is a full,'clear, and exact descriptionof theprnciple or characterwhich distinguishes my invention from all other things before' known, and of the manner of making, constructing, and using the same. V

' My inventronrelates to amethodof prepa-ringm'etal or second patterns'for' molding in sand to obtain'castiugs. The molding of pat- Yterns `of irregular figures isgenerally' attended Witlrgreat difficulty, particularlywhen the pattern is not made in parts, which is usually the case with second patterns-#thatl is,- 'castings in'metal made `by molding the original woodenpattern in sand. Thelchiefpdj-iclllty arisesv from the separation of the sand .in the two.part'-ask, so that after thc pattern i has been removed the two parts'JoT the moldshall comc together properly. 'This `is avoided by a method now in use of producing the metal or second pattern by first molding' the'block; pattern (the wooden pattern),in sand-in the two-part flask, and, after the block-pattern has been removed, separating the cope from the nowelto the distance of a quarter of` an inch,

more orjless, and, after the said open space has been closedup 4allaround with sand or other means,` lluliiing'in the metal, which will 4produce a casting with each half .of4 the pattern cast on one sident a plate equal in thickness parts of the sandniold will come together accurately;"bi1t the-form of the pattern `is sometimes suchth'at ifA cast on a molding-plate,

as above described, in cooling the contraction' will be unequal and cause the `plate to bend,

and,b esides this, most foundries have large collections of metal on ,second patterns made and collected at great epense.

The object of my invention is so toprepare 'metal or second patterns-as to avoid all these diiculties, audat the salue time' make use of j or y metal or l second patterns. already prepared without the'molding-plate; and to these' ends' my invention cousistsin molding a nictal patf,

tern in sand ina two-partilask, andlthen s eparatingfthetwo parts of the flask' to the dis: cont lonelquarterfof an inch, more plate to'iit that face of thepatt'ernwhich was separated fromthe sand, 'so that when removed from the mold and the pattern secured to the plate'the pattern should project from one face ofthe plate,` the ligure of 'theother face 'of` the pattern being represented on the other face of the plate. .The plate thusjprepared and at ltached tothe pattern ,is tobeused in molding "in the manner to be hereinafter described; lI will now describe one ofthe modes of pro-l cedureiwhich has heretofore been employed.

A'. block pattern trepreseutedatlig.. 1

taken and molded'in'agtwo-part flask, as represented at Fig. which isa longitudinal sec-` tionof the pattern so molded. The `pattern is' then removed and the two parts of thelask` 4put together, but separated as in Fig. 31eavinga space yof one-quarter of an .inch (more or less) between the two,and walled up withsand allaround the flask, to prevent the metal from running ontpf the space between the two parts of the' flask. The casting produced from this will be such assis represented b'y Fig.14, with ionehalf of :the patternprojecting from .each faceof the plate. To mold 'fromthis second pattern, 'thepowel a is placed ,on one face o1 `thepatternb and rammed full of sand. The

nowel,wi th the pattern Ain "it, is tlien'reversed,

andthe copec put onto the other \faceof the `pattern,Fand that is also rammedfiill of sand. The cope-is then removed, the'pattern taken out,au d the two-parts of the askput together ready-` for casting, Lhe casting. produced froniv this molding will be like the original pattern V-exceptfin "its reduced. size, due tothe conti-ac tiionof l theinetal in cooling; butfthe casting thus produced will be asi much vless than the' second pattern .as the second `pattern isless thanfthe original*block-pattern, for `there are two contractions lrom the original Ilolo'ck-.pat-` tern.

For variousV kinds. of castings the method above described will not'` dosuchil castings,

for instance, as would from their peculiarity .of forni tend to warp the plate iu cooling; and,

(with the patterns retained infonef part of-the mold, running in metal to cast ai mold. in a two-part flask in the usual manner,

and when so molded I lif't the cope e, Fig. 5, from the nowelf tothe distance of one-quarter of an inch, more or' less, leaving the metal pattern d in the sand in the nowel, and after the moldwhas been surrounded, as in the first ex@ ample, I pour in molten composition of metal `consisting of zinc, nine parlisybis'niuth, two

parts, and antinlony, two parts, by weight.

This will produce` a plate, g, one face .of which will be accurately fitted to one face of the metal p ttern, while the other face of the said plate will present the salme gure as that face of the pattern which is fitted' to the plate. It' in cooling the plate has. becomebent, it can be straightened, and then the metal` pattern secured thereto by screws or rivets, as shown in'Fig. 6. From the pattern thus fitted t'o a` plate I mold in the same'lnanner as `first above described.

The composition which I .lave above described will not contract in cooling,'or, if at all, only to an immaterial extent.' Any othermetal or composition of nietal may 'b e `used for the compound above specified; but in all instances it ywill be found advisable to use some compound or alloy which will not contract,or do so very slightly.. The contracting` of the plate will not, however, injure the pattern, as that face of the pattern which is to produce the part of the casting requiring accuracy can be left` in the sand, sov that the `other face, not requiring accuracy, will be produced onthe plate.

-What I claim as my'inveiition, and desire to secureby Letters Patent, is-

Preparing'second patterns by molding metal t pattern'sin two-part molds, and then separating the two parts of kthe, mold, the 'pattern being left in the sand to cast a plate fitted to the metal pattern so molded as specified, so that the pattern canbe attached to the plate and the two be used in molding to produce castings, substantially as described.

FRANCIS N.` STILL. Witnesses:

ALEX. PORTER BROWNE. CAUsN. BROWNE.

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