US480232A - Craft c - Google Patents

Description

(No Model.

0. G. CARROLL. APPARATUS FOR MELTING AND GAST ING METALS.

No. 480,232. Patented Aug. 2, 1892.

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WITNESSES:

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' UNITED STATES PATENT @FFICE.

CRAFT O. CARROLL, OF NEW YORK, N. Y.

APPARATUS FOR MELTING AND CASTING METALS.

SPECIFICATION forming part of Letters Patent No. 480,232, dated August 2, 1892.

I Application filed September 1891. Serial No. 404,890. (No model.)

To all whom it may concern.-

Be it known that I, CRAFT O. CARROLL, a citizen of the United States, and a resident of the city and county of New York, in the State of New York, haveinvented certain new and useful Improvements in Apparatus for Melting and Casting Metals, of which the following is a. specification, such. as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to that class of melting and casting apparatus in which the metal is fused in acrucible and introduced into the mold by means of pneumatic pressure, and more particularly to those designed for use by dentists in casting dental plates, crowns, and bridges, and is an improvement on the apparatus shown and described in United States Letters Patent No. 382,087, granted upon the application of J. E. Holmes May 1, 1888.

The object of my invention is to do away with many of the difficulties heretofore experienced with this classof devices, and this I accomplish by means of an apparatus extremely simple in construction and easy of operation, which is fully disclosed in the following specification, of which the accompanying drawings form a part, wherein similar numerals of reference designatelike or equivalent parts wherever found throughout the several views, and in which- Figure 1 is a view in central vertical section of my improved melting and casting apparatus; Fig. 2, a view of a detail thereof, parts being broken away; and Fig. 3, a view ofthepneumaticcastingdeviceconnectedwith the crucible, the latter being shown in central vertical section.

Referring to the drawings, the numeral 1 designates the burner, preferably of metal and of annular form, as shown, having a central chamber 2, open at the top and provided with a central hole in the bottom, which chamher 2 is surrounded by an outer circular chamher 3, closed at the bottom and provided at the top with a covering-ring 4, having a series of holes 5, beneath which is placed a ring of wire-gauze 6. Entering this circular chamber 3 at any convenient point is a pipe 7, provided with air-holes S and an interior gaspipe 9, through which gas and air are fed to the burner, as hereinafter more particularly set forth.

The ring at, which forms the top of the circular chamber 3 of the burner 1, is provided with a number of upwardly-projecting studs 10, upon which rest a hood or cover 11, preferably of the conical form shown and consisting of a metallic outer casing 12, having an inner lining 13 of asbestus or other nonconducting material and having a vent-hole 14c and peep-hole 15, which latter may, if desired, be provided with a covering of mica or other suitable substance.

Within the central chamber 2 of the burner 7 1 is placed a mold 16 of any, desired form of construction, but preferably of that shown, the flask consisting of two parts 17 and 18, held togetherby screws 19 at the bottom and by a washer 20, fitting around the neck 21 at i the top and having a filling 22 of plaster-ofparis or other suitable material, through which a duct 23, through which the molten metal is introduced, passes from the neck 21 to the metal-chamber 24.

Upon the top of the mold 17 is placed a crucible 25, preferably of the form shown, made of soapstone or other suitable material and having in the bot-tom thereof a downwardly-depending plug 26, which may be formed integrally therewith, but which is preferably formed of metal and attached thereto by a screw-thread, and this plug 26 is made of such size as to fit tightly into the neck of the mold-flask, and in connection with a soft washer 27, preferably of asbestus, to form an air-tight joint therewith and running through this plug 26 and the bottom of the crucible is a hole or passage 27, which registers with and forms a continuation of the duct 23 in the filling of the mold-flask, which leads to the metal chamber 24 thereof.

The numeral 28, Fig. 3, designates a plug, of soapstone or other suitable material, of such size as to form an air-tight stopper for the top of the crucible 25 provided with a central hole into which is fitted a tube 29, connected by means of a flexible rubber tube with a pneumatic bulb 31, by which air may be forced into the interior of the crucible 25.

The operation of the device is as follows: The mold having been properly prepared and fastened together by means of the screws 19 and Washer 20, or in any other desired manner, the same is placed in posit-ion in the central chamber 2 of the burner 1, as shown in Fig. 1. The asbestus washer 27 is then placed upon the plug 26 of the crucible 25, which is then forced tightly down into the neck of the mold-flask, when the crucible will be in position to be filled with the appropriate quantity of metal, after which, gas being admitted through the pipe 9 and ignited at the holes 5 at the top of the burner, the hood or cover 12 is placed in position over the crucible 25, as shown in Fig. 1, and the parts are allowed to remain in that position until the contents of the crucible have fully melted. The gas with which the burner is fed, flowing into the pipe 7 through the pipe 9, draws with it a large quantity of air through the holes 8, and, this being mingled thoroughly with the gas in passing through the chamber 3 and wire-gauze 5, each of the holes 5 becomes a Bunsen burner, and the flames being directed toward the centerof the hood by reason of the conical shape thereof, and the air-current which is drawn in under such hood or cover 12, causes great heat to be concentrated upon the crucible 25, and the metal therein is soon melted at the same time a sufficient quantity of the heat generated is directed against the top of the mold, which projects, as shown, slightly above the top of the burner 1 to heat the same to the degree required to obtain a perfect casting. The mold and also the joint between the same and the crucible being air-tight, it is impossible for any of the molten metal to flow into the mold untiltheoperatorsodesires; butwhen the metalis in the propel-state, which can be told by looking into the crucible through the peephole 15, the cover or hood 12 is removed and the plug 28, connected with the pneumatic bulb 31, is fitted tightly into the top of the crucible, as shown in Fig. 3 and in dotted lines in Fig. 1, and by simply forcing air through the bulb by compressing the same in the usual manner the molten metal is then driven by the pneumatic pressure thus obtained into the inetal-chamber of the mold, from which the casing may be removed in the usual manner when the same has sufliciently cooled.

The process of forming the metal chamber of'the mold, the ducts communicating therewith, of placing the teeth therein, and of removing the casting is well known and is preferably the same as that described in the United States patent hereinbefore referred to, although any form of mold desired may be used.

It is evident that burners other than those suitable for gas may be used, and that many other changes in the construction, combination, and arrangement of parts of my improved melting and casting apparatus may be made without departing from the scope of my invention, and I do not limit myself to any particular form thereof; but

Having fully described my invention, its construction and operation, what I claim, and desire to secure by Letters Patent, is

1. The combination,withan annular burner, of a mold-flask supported therein so that the flame-openings of the burner are at or near the top of the flask, a crucible mounted upon the mold-flask and in communication with the metal-chamber of the mold, and a removable conical hood or cover mounted upon the burner and inclosing the flame -openings thereof and the crucible in such manner as to direct the flame from the burner-openings upon the crucible, substantially as shown and described.

2. In an apparatus for melting and casting metals for dental orother purposes, the combination, with an annular burner having flameopenings in the top thereof,of a mold-flask supported therein so that the top of the burneris at or near the top of the flask, a crucible mounted on the top of the flask and in communication with the metal-chamber thereof, a conical removable hood or cover mounted upon the burner and inclosing the flame-openings thereof, so as to direct the flame upon the crucible, and means for forcing the molten metal from the crucible into the metal-chamber of the mold-flask after the hood or cover has been removed, substantially as shown and described.

3. In an apparatus for melting and casting metals for dental or other purposes, the combination, with an annular burner, of a moldflask supported therein in such manner that the flame-openings of the burner are at or near the top of the mold-flask, a crucible supported on the mold-flask, provided with a duct or passage through the bottom thereof which communicates with a duct or passage in the mold-flask leading to the chamber thereof, the joint between the crucible and the moldflask being air-tight, and means for forcing the molten metal from the crucible into the metal-chamber of the flask, consisting of a flexible tube and pneumatic bulb, substantially as shown and described.

Signed at the city and countyof New York, in the State of New York, this 2d day of September, A. D. 1891.

CRAFT C. CARROLL.

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