US970949A - Apparatus for casting under pressure small metal pieces. - Google Patents

Description

f n B. PLATSGHIGK. f maximus ron osma umm PRESSURE SMALL mm. mons. APPLmATIoRUmm Nov.25..1au7. Y

` QTCLQL. Patented sept. 2.o, 1910.V Il. I v3 SHEETS-BHEET 1.

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- APPARATUS FOB OASTILG UNDBRTRBSSURB SMALL METAL PIECES.

APPLICATION FILED HOY.25.1907.

Patented Sept 20,1910. Y

f f B.PLATSGH1GK. LlPABATUS'FOB OASTING UNDER PRESSURE SMALL METAL PECES. i l n Hummm! FILED xov.25,19o'1.

Patented sepa 2o, 1910.

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, :BENVENUTO PLATSCHICK, or PARIsyrnaNcE;

APPARATUS FORk CASTING UNDER PRESSURE sMALL METAL' PIECES.

To all wlwmit may concern: v f Bc 1t lknown that `'1, Brzsvnr; Uro Peers einen, au Italian subject, residing atsParis,

5l"Is Rue Ste. Anne, in the Republic oi vFrance, manufacturerof surgical instruments, have invented certain new and useful lmprovenunts in Apparatus for Cast-ing Under Pressure Small Metal Pieces, of which the following is a specification.

In the mamifacturevot small cast metal pieces, such as is obtained by casting molten gold in a mold of refractoryflnaterial, the )enetration of the metal into the narrow 0r iielicately hollowcd out parts of the `mold presents lsome ditliculty on account of the physical Aproperties of thc goldorfother molten metal. If suitable contrivances were not resorted to, the moldings obtained would be rough and of no use.

The contrirance the most often used `in the dental art consists in providing the walls of the cavity of the mold with a sheetor leaf of platina; on` account of the ailinity 0f these metals, the molten gold takes exactly the shape of the platina lining and hence that of the mold.

In order to avoid the use of platina, en-

deavors have been made to apply the pres-y sure of a gas to force the molten gold mto the mold and cause the gold to take the shape of the mold in every detail. This method gives good results, but thev apparatuses hitherto provided for carrying it outiu the dentallaboratories have drawbacks which prevent their use 'rombecoming general. Some of them require the use. of reservoirs of compressed oxygen, others the working ef a pump before each operation, and others again can not operate without an electric current which produces a heating arc in a closed vessel, the latter being eonnected with a reservoir of compressed gas.

For the purpose of providing an apparates more convenient than those justmez'.-

tioned and which requires neither an elec-- tric current, nor compressed oxygen, no1-a pump, nor pipes for gas under pressure, this invention consists in combining' with the flask or investment cup containing the mold a small renerator of gas or of vapors capable of giving oll" in a few moments,lat each operation. the quantity of gas or ot vapors required for forcing the molten metal into the mold. Theconstruction of this gener- Serial No. 403,761;

by a .chemical reaction, bythe explosion of -aneaplosive matcriah'by the expansion of a liquefied gas,'by avaporization of a liquid, or by other similar means In any ease, it, will be eomparat'ivlj' small and arranged adjacent to. the `furnace, so that. neither the gexwratmgnor the ronduit, il' any which enables it to communicate with the, furnace, will be `eumbersonu. Y Y

t At the beginning of each operatiomthe generator will heenabled to rproduce the required pressure when the metal will be molten and sufficiently heated, the furnace willy vhermetically closed as quickly as possible', and the'gcnerator will be putin that. the ressurc may act on the molten metal be ore the latter begins to stiften. \Vhen gold is used, the rapidity with' which this metal loses its heat again constitutes a diiliculty in that it tends to thicken as soon as itis no longer heated, especially when vthe quantity is a small one, as in the present case; hitherto this dillieulty has only been overcome by the use of heating hearths `of Very high ten'xperat-ures, such as the electric are. or the oxhydric blow-pipe; the use of such special hearths requires costly installations; which cannot be atlorded in all labora# toi-ies. l

made, as a heating hearth, of an ordinary gas blow-pipe suitably modified so aus to gire a sullicientlv high temperature. For this purpose, the mixture of air and gas is caused to pass into a tube heated by a supplemental flame, so as to'heat the. gas and the air before retwhing the inlet, to the blo\\'-pipe. The flame thus becomes much hotter; it quit-lily melts the gold and carries the same to a very high temperature, so that. the metall does not run the risk ofy losing its liuidity during the comparatively short lapse of time required for closing the furnace and forcing the metal into the mold. The apparatus thus combined thus requires neither compressedoxygen, nor electricity for melting the gold and tor casting the .saine under pressure, so that the `said ap- In the accom mnvin drawinvs. Fieure 1 v b P3 alor mayv vary according as to whether the i is a side elevatira, partly in section, of one communication with the furnace. in orderv or vapors under pressure are produced `According t-o'this invention, nseniay be vinder open at the top in which y. form of thisimproved apparatus; Fig. 2

.The said lid is secured to a vertically movable 'rod V5,' guided in arms 6 and 7, which gare. secured to a rigid upright or posi;- 8. On the rod 5 is fixed a. socket 9 carrying a valve casing which carries in its turn a gas generator. 11.

A spring 12, interposed betweenv the firm 7 and the socket- 9, holds the rod and the y lid normally raised. On the upper part of the rod 5, which terminates in a head 13, is aslidable frame 14, which is also enabled to slide on a rod having s head 16, and which is arranged in the sameaxial liner as the rod 5. A spring 17, interposed between the heads 13 and 1G, tends te hold the rods 5 and 15 away from each other. The upper rod 15 is connected by a bifurcated part 18 with a lever 19 pivoted to the post 8; the

kbif'rircated 'part 18 carries a finger 20, so l arranged as to be able to bear on the rod 21 ot' the valve and to open 'the latter when the rod 15 is brought toward the rod 5.

On the support of the apparatus is secured a. blow-pipe 22, the mixing tube of which is heated, at a certain distance from its outlet, by the llame of a Bunsen burner 23, so that the combustible mixture is carried vto a high temperature already before bursting into a flame. The very highly heated flame of this blow-pipe is led to aV piece of gold 24, located in the upper' cavity of the mold 2.

At the beginning of the melting operation,

r n the gas generator 11 is put under pressure.

In the embodiment shown, the gas is produced by the decomposition of a mixture f tartaric acid and of a carbonate; the mixture of these materials is placed in a dry state in a small perforated box 25 and is dissolved at the proper time by the water contained in a cup 26. For that purpose, the generator 11 is mounted on the valve casing 10 in such a manner as to 'oe enabled to swing around the horizontal spindle 27; to charge the generator, it `is turned upside down, its lid 28 is taken oil, its contents are emptied, and the cup 26 full of water is inserted in the generator, and then, above the cup, the box 25 full of the dry mixture of acid and of carbonate and, lastly, the lid 28 is put on again. At the proper time, all that need be donc is to invert the generator 11 into the position shown in the drawing to cause the Water to fall down onto the reagents and to produce carbonio acid. As the vulve of the casing 10 then lies closed, the pressure rises avesse inthe generator; it is indicated by s.' pr sure gage 29.

When the gold becomes-'k molten and is I moved down. On bein moved down, the

lever 19 carries down withV it the red 5 and sufficiently heated, the lever 19 is quickly 'I l the members carried by the' latten. for the' to permit the rod '21 being moved down by yields and the finger 2O opens the valve, so

yspring 17 is stronger than the spring 12;v

the lid'3 is thus hermetically a plied to thev vflask 1 before the spring 17 yiel s sufficiently the finger v20. V0n the further downward.,v i i movement of thevlever 19, the spring 17" dium of a-conduit 30 made` in the rod 5... 'Y

The pressureof the Vcarbonioy acid then acts on the drop of molten gold and forces the same into the mold 2, Where it assumes exactly the shape of the walls of the latter.

Immediately afterward lthe lever 19 moved up and the mold is withdrawn from the tiaslr.

It will be understood that the lever 19 has only to be moved quickly down to pro-v duce the closing of the flask and the opening of the valve almost simultaneously and iny a very short time; therefore, the molten gold does not stiften before being forced into the mold, and all the more so as the s ecial" blow-pipe.hereinbetore described whi e be l y ing neither oxhydric nor electric, carries the gold to a temperature very much above the melting point. V

If desired, thereinay be easily combined with my apparatus a device which. will permit of the gas being shut oli :it the same time that the lid 3 closes the furnace 1.

Instead of an upsetting generator, there may be used any other suitable gas gener` ator, as, for instance, a receptacle nciosing what is called the spendet ampulla charged with liquelied gas; the valvev red 21 will in this case, be re laced by a needle to puncture the said amp ,ilo` u la. The pressure ma ,1' also be produced in the enerator by, L

the heating of a volatile liqui or b any similar or equivalent means. The sai gencrater ma f be combined, not with the movable lid o the furnace, but with a fixed part' of the latter; suchk a modificationdoes not recent the valve or cock, or the puncturmg needle, or the firin -pin of the explosive cartridge, or the like, rom being controlled by the mechanism which operates the furnace lid in the same conditions as aforesaid or in any equivalent manner. lhe pressure generator may also be located within the lid; the heat radiated by the flask and the adjacent' parts of the furnace ma then made use of `to volatilize a suitab e material placed in the generator, that is in the 11d when the latter is being applied lonto the flask. That Will allow of the construction of the apparatus being simplified. And infdeed, the generator may now consistl simply of a receptacle or oir'l any suitable sup ort enabled to malntain in the lid the liqui or solid material which is to be volatilizedwhen the lid is'appled onto the furnace. For instance, iny FiO'. 2, the lid 3 of the flask 1,'carried by a rod 5 which can be moved by means of the lever 19, incloses a pad 31 of asbestos, or other absorbing material such as blotting paper, or the like, serving both to support by capilarity either water or another volatile liquid and to form a tightjoint between the lid and thev mold. This rod is normally held in the raised position by a Spring 12. p aced on the mold 2 is molten and carried .to the required' temperature, the lid 3 is quickly moved down; thc heat radiated by the mold, the gold, a' i the upper part of the furnace, produces instantaneously the Yaporization of a small quantity kof water and hence a steam pressure above the gold, so that the latter is immediately forced into the mold. All that need be done therefore is to wet the asbestos pad before each operation. For that purpose, use may be made of a rod 5, through which extends'a conduit 32 and which is provided with a funnel 33 and also with a cock '34. The liquid to be vaporized being placed in the funnel 33, one has onlyto turn the cock for an instant to charve the asbestos with a suitabley uantity of iquid. litV will be understood' t at the asbestos may be moistened in any other way. Y l y l Fi 3 shows a pair of tweezers, one branch 35 o which carries a flask 1, and thevother branch 36 a lid 8, the said flask and the said lid being similar to those described with ref- When the mass of gold 24' erence to Fi'. 2. In this case, the tweezers are held inthe hand to present the gold 24,

and the two branches are brought to i iven off as hereinbefore menflask lid, a mold inthe las anda cushion of porous material on the inner face of they lid, designed to be inpregna'ted by a volatile Y substance and used for the purpose of giving v off the vapors produced by the-said substance under the influence of' heat.V y f- 2. An a paratus for casting small metal pieces un er pressure, comprising a flask, a, iask lid, a mold in the flask, a cushion of porous material in the lid, a lid rod, a support having a socket to guide the lid rod a. spring adapted to, raise or lift the said rod, and a band lever and jointed to said rod.

pivoted to said support imy 3. An a paratus for casting small pieces un er pressure compnsmg a. flask, a. flask lid, a mold in the flask, a cushion 'of porous material in the lid, a tubular lid rod,

a funnel and a cock on said rod,.and means whereby saicl rod may be raised and lowered.'

` In testimonythat I claim 'the foregoing as my invention have signed by name in presence of' two subscribing witnesses.

BENVENUTO PLATSCHICK. Witnesses:

MAURICE Roux, Cnanms JARDxvnL.

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