US1374855A - Casting - Google Patents

Description

S LAKE.

CASTING.

APPLI CATION FILED Dc.29. 1919.

' 1,874,855. Patented Apr. 12, 1921.

INVENTOR.

A TTORNE Y.

provided with a smon mixn, or unreal), conunc'rrcur.

sesame.

Specification of Letters int nt Patented Apr. 12, 1921.

Application filed December, 1919. Serial No. 348,074.

To all whom it may concern:

' Be it known that I, SIMON LAKE a citizen of the United States, residing at Milford, in the county of New Haven and State of Connecticut, have invented a certain new and useful Improvement in Castings, of which the following is a full, clear, and exact description. This invention relates to theart of casting, and, more particularly, to a method of andapparatus for producin castings of a, very fine, intricate and fragi e nature. The object of the invention is to provide a method and apparatus whereby aithful reproductions in" metal 'or othercplastic of such articles as flowers, twigs, insects and the like smalland delicate articles may be made.

1o this end the invention consists in sur rounding the object to be reproduced with a.

mold forming material of suitable character,

destroyin the object within the mold, removin t e thus destroyed object from the mold t us leavin a cavity forming a faithful impression 0 it therein, forcing fluid or plastic metalor other suitable material into the thus produced mold cavity so as to completely fill the same, and finally, after the plastic has set or solidified, removing the surrounding mold material; and the invention consists further in apparatus for performing this method all as I willproceed now to explain and finally claim.

- In the accompanyin drawings illustrating the invention, in t e several'fi ures of which'like parts are similarly desi ated, Figure 1 is a section taken in the p ane of line 1 -1, Fig. 2. Fig. 2 is a plan view of the apparatus for carrying out my method completely set-up. Fig. 3 is a sectional view showing the manner of carrying out one ste .of my method. f

ft will be. understood that the drawings are illustrative merely of one kind ofapparatus for carrying out my method, it being'possible that others might be designedto produce the desired. result; but in the interest of clearness of the understanding of my invention reference will be had to the particular form of apparatus shown.

Referring to Fig.3, a metallic c linder 1,

ining of suitab e refrac-,

tory material 2 which is a non'conductor of electricity, and screwthreaded at both ends as at 3, is'supported by meansof a collar purpose able.

4 threaded to one end, upon a suitable support or platform 5. In this cylinder is positioned the article fi which it is desired to reproduce, here shown asa flower, by means of a particle of wax or the like easily melted substance 7 into which the stem is mserted, the leaves 'and petals being supported by means of threads 8 attached thereto and to a temporar supporting cross-bar 9. I consider it at visable, when the article to be reproduced is of a very fragile nature or its parts are very thin or tissue-like, to di it'- into melted paraffin-wax or the like, be ore positioningit in the cylinder. This dipping will form a thin coating covering the entire article, thereby giving it more body. Or the article ma be; frozen to give it rigidity.

After 1: e article is properly itioned and supported, the cylinder is fil ed with a refracto electrical-conducting material 10, see 1 1, in a fluid state, and for this have found that a mixture of plaster-of Paris and graphite is quite suit- I also consider aquada a mixture of deflocculated Acheson graphite in water in which it remains suspended, manufactured by the International Acheson Graphite Company, of Niagara Falls, New York, a

suitable Pgraphite for mixture with the plas-- ter of aris. This refractory material is allowed to solidify to form a. mold around with refractory linings 13, and stuflingi boxes 14 and 15 respectively, also lined with refractory material.

Through the 'stuflingbox 14 is inserted a tube 16, preferably of metal, connected by a tube 17 with a pump (not shown) which may be used to induce either pressure or a vacuum within t 1e mold cavity, as will later appear. To this tube 16 is also connected one terminal 18 of an electric circuit, the other terminal 19 of which is connected with a hollow electrode 20, preferably of carbon, inserted through the other stuliing-box 15. This electrode is adjustable by means of a yoke 21' through which it passes and to which it is secured by means of a set-screw 22, the yoke being supported upon the sleeved ends of thumb nuts 23 capable of screw-adjustment upon rods 24: fixed .to the head 12.

By the means just described the electrode 20 will be adjusted so,that its inner end is in contact with the refractory. conducting charred material is loosened from the mold andforced out of it through the opening in the electrode .20, thereby leaving a: mold cavity which is a true duplicate of the article which formerly filled it The depression formed by the removal of the particle of wax 7, combined with the space caused by the thickness of the re fractory lining 13 of head 15, forms a cavity 25 which is now filled with molten metal or other plastic in fiuid form. When metal is used this as accomplished by introducing a rod 26 of the metal to be used through the hollow electrode 20, switching on the current, and movingthe electrode away from the mold to form an arc, the intenseheat of which will melt the metal of the rod. When sufiicient molten metal has accumulated in'the cavity 25, the electrode 20 is moved forward therebydisplacing all air and gases from the mold cavity. In this operation it may be assisted by suction from the pump connected'with tubes 16 and 17. The rod 26 is now operated as a plunger by means of thumb-nuts 27 carried by a yoke 28 to which the end of rod 26 is fixed as by set-screw 29, the nuts 27 being threaded on the rods 24 in a manner similar to the nuts 23. By moving rod 26 forward it will exert pressure upon the molten metal in cavity 25 and force it into all the interstices of the mold cavity, any surplus being forced out of the openings formed by the threads 8;

and this pressure may be augmented by op-.

erating the pump connected. to tube 17 to create a vacuum in the mold.

It will be understood that the moltenmetal will not be chilled and hence become sluggish upon entering the mold. because the material thereof is at a high temperature due to the heating effect of the electric current passing through the material of the mold;

In order to have atight sliding fit between the rod 26 and the interior of the electrode 20, I-provide a packing of plastic material of a suitable nature adapted to be forced into an annular cavity 30 by the setscrew 22, thus preventing the molten metal from backing out of the electrode past the =rod26 when pressure is applied.

If. plastic other than molten metal be used, it may be introduced into the electrode 20 and then forced therefrom into the mold I cavity by any suitable plunger.

' Of course, the more minute the interstices of the mold cavity, the greater the pressure on the plastic must be in order to have it fill them.

. When the molding action is complete, the

electric current is switched off and the mold with its casting allowed to 0001, after which the mold material may be removed.

It will be understood that various changes in the steps of my method, and in the method itself, and in' the apparatus, may be made without departing from the spirit of the invention of the scope of the claims following:

WhatI claim is i 1. A method of casting, comprising forming a mold of electrical-conducting material around the article to be reproduced, destroying the article within the mold by the heat of an electriccurrent passing through'the mold material, removing the remains of the article, filling the mold cavity thus formed with a plastic substance, and removing the mold-material. i I

2. A method of forming reproductions of articles destructible by heat, comprising forming an electrical conducting mold around the article, destroying the article in the-mold by the heat of an electric current passing through the mold material, removmg the remains of the thus destroyed-an ticle by introducing -a fluid under pressure to the thus formed -mold cavity, filling the mold cavity with plastic substance, and removing the mold.

3. A method of casting metal reproductions of articles, comprising forming a mold of electrical-conducting material around the article to be reproduced, passing an electric current through said mold to heat the same and thereby char said article, removing the chared remains ofthe article by introducing r a fluid under pressure to said mold to i form a mold cavity, removing any gases remaining in said cavity, forcing molten metal into said cavity under pressure to fill the same,

allowing the metal to cool; and removingthe mold material from the castingthus formed.

1. In an apparatus for producing castings, a mold having electrical conducting properties and means for-heating the same by passing an electric current through it, means for creating pressure or alvacuum therein, and means for introducing casting material to said mold under pressure.

5..In an apparatus for producing'metal and the like castings, means for forming a mold around the article to be reproduced,

means for heating the mold bypassing an electric current therethrough to destroy the article, means for removing the remains of the article to form a cavity, and means for filling said cavity with plastic material.

6. In an apparatus" for producing castings,

a mold of electrical conducting material formed around the article to be reproduced and containing same, means including electrical connections adapted to supply current for heating the material of the'moldto char said article, means for introducing fluid under pressure to. said mold to remove the charred remains of the article, and means for introducing molten metal to the mold cavity thus formed.

7. In an apparatus for producing metal reproductions of articles destructible by heat, a mold of conducting material formed around and containing the article to be remetal into said cavity under pressure.

-- said mold to remove sai'd destroyed article 25 and thereby -produce a mold cavity, and means including the other electrode of said current supplying means for producing an arcto melt metal and force the thus melted 30 In testimony whereof I have hereunto set my hand this 27th day of December,- A. D.

SDION LAKE. Witnesses:

' LUCY BrMOLAiUGHLiN,

R; M. Kare.

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