US1046976A - Inlay and bridge casting machine. - Google Patents

Description

U ITED STATES PATENT OFFICE.-

ASA r. eoeswELI or KI RiWIN, KANSAS.

- INLAY AND BRIDGE CASTING MACHINE.

l 1 4 ,97 Specification of Letters Patent. t t d 10, 1912 i I Application filed April 3, 1911. Serial No. 618,708.

.- cam-Toad whom it may concern:

Be it known that I, Am F. Coeswnnt, a citizen of the UnitedStates, residing at- Kirwin, in the county of Phillips and State of Kansas, have invented certain new and useful Improvements in Inlay'and Bridge Casting Machines, of which the following .isa specification,

This invention relates to improvements in 10 casting .machines, for use in the practice of dentistry, and my objectis to 'produce a simple, inexpensive machine of this character whereby perfect, sharp-edged inlays, crowns, bridges etc., can be produced at a small expenditure of time and labor.

he present invention relates more particularly to a novel crucible and-anovel hopper therefor, the latter being provided chiefly to save the time and labor now re- 2 0 quired in forming the usual hopper in the investment surrounding the wax impression.

The novel feature of the crucible resides more particularly in the provision of means to prevent any passage of air between the 26 inner walls of said crucible and the investment, to the end that suction applied tothe latter is concentrated to the region of the' :sprue-gate and the cavity. left in the investment by the wax impression. Thus a 30 vacuum may be formed within the cavity and when the molten metal to form the cast flows into said cavity through the sprite-gate, a perfect cast in produced, as the metal being unopposed by airpressure,

flows into all of, the interstices of the cavity.

-In order that the. invention may be fully understood, reference will now be made to the accompanying drawing, in which:

40 Figure 1 shows a vertical sectional view of the machine assembled for use. Fig. .3 is a detail perspective view of the hopper forming part of the invention. Fig. 3 is a plan view of the crucible. Fig. at is a vertical section of the crucible. and drawing the air from said cavity In carrying out the invention, I employ a through cup 4. stem 5, duct. 53, pipe (3, and

; couumrativcly heavy base I. having a centube 7. As the top '10 of the crucible is nontral boss 2, with an L-shaped duct- 3 leading porous and the hopper 19 is substantially to the top and one side of said boss. nonporous. air cannot pass through .the 105 4 designates a conical cup supported by a. porous iuvcstu'icnt. except in the region contubular stem 5, the lower (breaded end of taining the cavity -and the gate, conse- \\'hich is screwed into the. upper portion of qucntly the vacuum produced in the cavity.

the base and connnuuicates with the-vertical aided by the force of gravity. will suck the leg of duct 3. metal from tbe hoppcr. down through the 110 (5 designates a horizontal pipe extending gate and into the cavity, producing a perthrough one side of the base and conununifeet east.

[eating with the horizontal leg of duct 3,

said pipe bcing provided at its outer end with a flexible. tube 7 having a mouthpiece 8.

9 designates a conical crucible adapted to fit snugly into the upper portion of cup 4 and provided with a top portion 10, sloping downward to a central opening 11.

' 12 designates a conical hopper adapted to fit snugly upon top 10 of the crucible, and provided with a circular boss 13 to fit into opening 11, said boss having a central sprue-hole 14 to receive the sprue A of a wax impression B. Hopper 12 is composed, preferably of fire-clay or other suitablematerial which will withstand a high temperature without cracking, and which has no aflinity for molten metal, so that the same will not adhere thereto.

In practice the crucible 9 is taken from cup 4, and the hopper 12 is placed in position thereon. The crucible and hopper are then inverted and placed upon a smooth sur face, after which the wax impression B and 3 sprue A are placed within the upturned crucible, the spruc A passing through hole 14, in the hopper, so that the same will support the sprue and the wax impression in upright position. The length of the sprue 35 determines the location of the wax impressi'on B within the investment C, which is now poured into the upturned crucible until the same is filled therewith. After the investment becomes set, the crucible and the hopper are turned right side up and the sprne is removed, after which the crucible is subjected to sufficient heat to consume the wax impression, which leaves a cavity wit iin the investment, said cavity communicating with a gate left by the sprue. Metal to form the cast is now placed in the hopper and melted, and when in a molten state, a vacuum is created in the cavity, by applying the mouth to the mouth-piece 8 a .ters Patent, is:

1. In a machine of the character described,- 15 a crucible, hav ng an integral top thereon sloping downward to a central opening, and

a hopper adapted to snugly fit said top and provided with a central opening.

2. In a machineof the type described a crucible formed w th an integral top that 20 slopes downward to a central opening, and aconical hopper that snugly'seat s on said f L01) and is formed with a central boss that projects down into the opening in the'crucible top and has a sprue-hole. 25

In testimony whereof I aflix my signature, in the presence of two witnesses.

ASA F. COGSWELL.

Witnesses:

F. G FISCI-IER, E. O. LILLIAN.

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