US723942A - Dental mold. - Google Patents

Description

'No. 723,942. BATENTED MAR. s1,- 1903.1. w. STREBTMAN.

DENTAL MOLD.

APPLICATION FILED MAY 27 1902.

N0 MODEL.

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UNITED STATES PATENT OEFrcE.

WILLARD STREETMAN, OF OLEBURNE, TEXAS.

DENTAL MOLD.

SPECIFICATION formingpart of Letters Tatent No. 723,942, dated.'March 31, 1903.

Application filed May 27,1902. Serial No. 109,218- (No model.)

To alt whom it may concern:

Be it known that I, WILLARD STREETMAN, a citizen of the United States, residing at Oleburne, in the county of Johnson and State of Texas, have invented certain new and useful Improvements in Dental Molds; and I do 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, reference being bad to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specification.

This invention is an improvement on the dental mold described in my pending appli-' cation, Serial No. 64,431, filed June 13, 1902, now patented, No. 700,855; and it consists in the improved construction of the lower part of the neck and the upper part of the flask, whereby the molten metal is kept from contact with the metal of the mold and so avoids being suddenly cooled. In my casting device referred to I found it necessary to have the neck very hot and the flask cool when the metal was poured in. With my present improvement both flask and neck may be heated and the metal be kept fluent until by agitation it is caused to settle down into every recess of the matrix and the gases be permitted to pass out from the mold.

The accompanying drawings illustrate the invention, in which Figure 1 is a side elevation, Fig. 2 an edge elevation, Fig. 3 an edge elevation, partly in section on line a: x of Fig. 1, and Fig. 4. a plan, of the top of the flask.

Like letters of reference denote corresponding parts in the views.

The letter A indicates the neck, and B-the flask, of the mold; These are made separately, and both the neck and flask are in two members separably united by the eyes and boltsct a b b.

The sides of both flask and neck are open, to be filled in with cement or other refractory material C D, in which the matrix for the casting is formed. The bottom surface of the neck and the top surface of the flask are plane and adapted to rest closely together and are provided with nibs b on the flask to engage notches a in the neck to preventlateral displacement of the parts. The inlet b of the flask is quite large, and the edges of the metal are covered with a layer or lining d of the cement. The neck a is also large and tapers uniformly downward to the bottom. Its exit a is large enough to admit a lining c'of cement over the edges of the metal bottom. This con- 'struction provides a continuous refractory channel from the upper edge of the neck down into the flask to the matrix, except along the vertical joint of the members of the neck, whereby the metal is to that extentkept from contact with the cold metal, which would too quickly absorb its heat.

Having now described my invention, what I claim, and desire to secure by Letters Patent, is

In a dental mold, a separable neck having open sides and a large exit at its bottom, cement therein forminga taperingchannel and completely overlapping the edges of said exit, a flask having a wide inlet, cement therein to contain the matrix and a channel thereto, and completely overlapping the'edges of said inlet, whereby a continuous channel of the cement ismade through the neck and flask to the matrix, substantially as described.

In testimony whereof I aflix my signature inpresence of two witnesses.

WILLARD STREETMAN.

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