US963418A - Dentist's flask. - Google Patents

Description

J. B. BUCHANAN.

DENTISTS FLASK. APPLICATION FILED APR.15, 1908.

963,418. I Y Paten tedJuly5g1910.

JAMES B. BUCHANAN, OF CHICAGO, ILLINOIS.

DENTISTS FLASK.

coasts.

Specification of Letters Eaten Patented J uly 5, 1910.

Application filed April 15, 1908. Serial No. 427,117.

To all whom 'it may concern:

Be it known that 1, JAMES B. BUCHANAN, citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Dentists Flasks;

and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to a novel construction in a flask for use by dentists in casting artificial teeth, the object being to provide a simple and eflicient device of this character, and consists in the features of construction andcombinations of parts hereinafter full described and claimed.

In theaccompanying drawings illustrating this invention: Figure -1 is a view of theflask devoid of the plaster-of-paris filling, showing the main and auxiliary sprue in place preparatory to introducing the filling. Fig. -2 is a central vertical section of the main sprue. Fig. 3-- is a cen tral vertical longitudinal section of the flask showing the same ready to receive the metal to be cast, the wax pattern and auxiliary sprue having been melted out and the main sprue removed. Fig. -4- is a top plan view of the flask showing the main sprue in .position therein.

The invention resides more particularly in the specific form and arrangement in a flask of main and auxiliary sprues whereby the metal to be cast is prevented from overflowing and is guided into the pattern cavity through a funnel shaped passage which latter is generally partly filled with excess metal, said pattern cavity and passage being horizontally disposed so that centrifugal force applied Wlll produce uniform density in the casting.

A feature of my invention consists also in the formation by large cavity in the flask, the bottom of which is disposed below the lowermost point in the'funnel shaped passa e so that the metal to be cast may be melte in said cavity and subsequently by rotating the flask carrier be forced by the resulting centrifugal force to flow into the pattern cavity.

My said flask consists preferably of a rectangular tube A of sheet metal open at both ends'and provided in one wall with a circular opening B through which the main curved that the main sprue of a sprue sprue C is adapted to project into the said tube A. Said sprue C resembles in form a distorted thimble and consists of a cup, the bottom portion of which is disposed eccentrio to the rim portion,'the peripheral wall of said cup being oint as at D which said bulged portion proects beyond the remaining portion of the wall lying between the same and the rim, said rim being bordered by an annular flange E. Said portion of the wall containing the said bulge D is ogee curved in vertical section and the opposing portion is so when the said cup is turnec upon the free edge of the flange E at the point disposed in vertical alinement with the bulge D as a fulcrum, no part of said opposing portion will strike the wall of the cavity formed by the sprue. In other words the curvature of the said opposing portion is eccentric to the above mentioned point in the free edge of the flange E, the lowermost portion of the cup being disposed at less radial distance from said point than is the meeting point of said opposing portion I with the diametrically opposite point in the flange E. At said bulge D I provide a plurality of needle oint projections F substantially horizontal y disposed upon which the larger end of a. conical wax sprue G is secured, the latter being molded in the cavity H in the filling I of the sprue C, the apex end of said wax sprue G being compressed against and thus secured to the crown end of the wax pattern J of the tooth to be cast.

After mounting the sprue G on the sprue C and mounting the pattern J on the sprue G, said sprue G is inserted in the opening B in the tubular casing A of said flask as shown in Fig. -1. Said casing A is then filled with plastic plaster-of-paris and after the latter is set the sprue C is removed. The sprue G and pattern H remain embedded in the laster-of-paris and are melted out by heatmg'the flask. The latter is then mount ed on the arm K of a rotatable spindle and firmly secured to the latter in any suitable manner, said flask being so positioned that the pattern cavity is farthest removed from the axis of rotation of the arm K. The

metal is now introduced in a finely divided cold state into the cavity L formed by the C and is melted by applying heat preferably by means of a blow pipe. As soon as the said metal is molten the spindle is revolved at'considerable speed so that bulged outwardly at one while introducing the plastic the resulting centrifugal force.throws the metal into the pattern cavity of the flask, such centrifugal force serving also to cause any air to be displaced and thus form a casting of uniform density as is well known. The delivery end of the funnel shaped passage M formed by the sprue G beln very small enables surplus metal to be easi y severed from the casting as will be obvious.

The device is very simple, efiicient and easily operated and enables castings tobe made which coincide in the minutest details with the pattern.

claim as my invention:

1. A flask comprising a tubular shell provided with an opening, a'main sprue comprising a cup laterally and having the portion of its wall opposing said bulged portion disposed eccentric tothe rim of the cup in alinement. with I said bulged portion, a projecting pin on the latter adapted to receive andsecure a wax sprue thereto, said wax sprue being adapted to support thewax pattern of the tooth filling in the and adapted to form porting the wax bulged at one point flask, said main sprue forming a melting cup in said flask having its bottom portion disposed below the juncture therewith of the passage leading to the pattern cavity.

2. A flask comprising a tubular shell provided with an opening, a main sprue rojecting through said opening and provided with a laterally extended lower end portion a lateral extension of the mam'cavity of the flask, a wax sprue adapted to be secured to said laterally extended portion of said main sprue and suppattcrn at its free end,

said main cavity formed by said main s rue constituting the melting pot and exten ing below the mouth of the pattern (aivity formed by the wax sprue.

In testimony whereof I have signed my name in presence of two subscribing nesses.

JAMES B. BUCHANAN.

Witnesses:

ARTHUR W. CAPS, RUDOLPH WM. Lorz.

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