US499015A

US499015A - downie

Info

Publication number: US499015A
Authority: US
Publication date: 1893-06-06
Anticipated expiration: 1910-06-06

Description

(No Model.

J; H. DOWNIE.- DENTAL FURNAGE.-

Patented June 6, 1893.

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UNITED STATES PATENT OFFICE.

JAMES II. DOWNIE, OF DETROITJVIIGHIGAN, ASSIGNOR TO THE DETROIT DENTAL MANUFACTURING COMPANY, OF SAME PLACE.

DENTAL FURNACE.

SPECIFICATION forming part of Letters Patent No. 499,015, dated June 6, 1893..

Application filed November 14, 1892. Serial No. 451,942. (No model.)

To all whom it may concern.-

Be it known that I, JAMES H. DOWNIE, a citizen of the United States, residing at Detroit, in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in Dental Furnaces, of which the following is a specification, reference being had therein to the accompanying drawings.

The invention consists in the peculiar construction of the furnace itself,in the peculiar construction of the muffle, in the peculiar devices for securing the muffle in position in the furnace, in the peculiar construction of the shelf at the mouth of the muflie, and in the peculiar construction, arrangement and combination of the various parts.

In the drawings, Figure 1 is a front elevation of myimproved furnace. Fig. 2 is a horizontal section centrally through the muffle. Fig. 3 is a vertical, central section on linens 0c in Fig. 2. Fig. at is a perspective View of the muffle detached. Fig. 5 is a detached perspective view of the muffle clamping ring and shelf.

My furnace consists of the furnace casing composed of the lower section A and the upper section B, preferably made in two parts, the lower section enlarged from the bottom upward to its upper end and the upper section narrowing from its lower end to its upper end. In the previous state of the art, if furnaces of this description were to be used, the lining was cast separately and the casing was fitted about it, and by making the casing in two sections, divided at the point of greatest width and narrowing from that point in a both directions,I am enabled to cast or mold the lining G into each section of the casing thereby insuring a perfect fit, preventing all necessity of trimming or fitting afterward and cheapening the manufacture.

At the top of the lower casing A is an exterior circular flange D extending around the furnace, except at the point opposite the muffle. The upper casing is provided with ears E and screws F passing through those ears and into the flange D, securing the two sections of the furnace casing together. At the lower edge of the upper section of the casing I form preferably a D shaped aperture in which I insert a muffle G which extends across the furnace chamber. This muffle is made of light metal, such as platinum, and is provided at its forward edge with a flange H adapted to bear against the outer face of the furnace casing.

Iis a clamping ring, corresponding in shape to the shape of the mouth of the muffle and adapted to bear against the flange I-I thereof and clamp the same tightly against the outer face of the casing, clamping screws J securing it in position. This ring is preferably made integral with a shelf K which. extends out from the lower edge of the muffle and forms a support for the articles which may be placed in the muffle or drawn therefrom. The bottom of thelower section of the casing A is provided with a central aperture in which the gas pipe L is screwed.

M is a supporting base having a corresponding central aperture to allow the pipe L to pass therethrough and to which the furnace is secured by means of screws N entering the bottom of the furnace casing, as plainly shown in Fig. 3. Around this base concentric with the casing A and separated a short distance therefrom, is a raised flange 0, within which is the lower edge of the conical outer casing 0 preferably of sheet metal and extending from the base M to the under side of the flange D. This I make of sheet metal and preferably ornamental or highly finished so as to add to the attractiveness of the furnace, and by forming an air space P between this casing and the furnace casing the heat of the furnace will not tarnish or injure the outer casing. To prevent possibility of this I form apertures)? at top and bottom to create a circulation of air through that air chamber.

Q is a dome shaped cap or cover, centrally apertured to embrace the furnace casing, bearing with its lower edge upon the flange D, forming above this flange an oven R.

R are suitable apertures or door openings formed in the sides of this cover through which articles may be placed upon the flange D to be heated or to be cooled to a lower temperature slowly after being drawn from the furnace.

' What I claim as my invention is- 1.. In a dental furnace, the combination 0 the furnace casing made in two oppositely tapering sections, a lining of refractory material molded therein, means for securing the sections together, and a muffle in the furnace, immediately above the upper edges of the lower section and extending across the same substantially as described.

2. In a dental furnace, the combination of the furnace casing made in two sections, a lining of refractory material therein, one only of said sections having a recess formed in its edge and a muffle located in said recess at the joint between the two sections, substantially as described.

3. In a dental furnace the combination of a furnace casing, an annular flange about the casing, a cap or cover for said flange forming the oven R in its sides within, and having door openings in its sides substantially as described.

t. In a dental furnace, the combination of the furnace casing, the horizontal annular flange surrounding the casing, the cap Q supported on the flange having apertures Rand the muffle opening on a level with said flange, substantially as described.

5. In a dental furnace, the combination of the furnace casing, a muffle, a marginal flange on the muffle, and a clamping ring secured to the casing for clamping the flange against the casing around the muffle, substantially as described.

6. In a dental furnace, the combination of the furnace casing, a muffle, a marginal flange on the muffle, a clamping ring secured to the casing for clamping the flange against the casing around the muffle, and a shelf supported by said ring, substantially as described.

7. In a dental furnace, the combination of the furnace casing, a muffle, a marginal flange on the muffle, a clamping ring secured to the casing for clamping the flange against the casing around the muffle, and a shelf formed integral with said ring and extending out on the plane of the bottom of the muffle,substantially as described.

In testimony whereof I affix mysignature in presence of two witnesses.

JAMES H. DOWNIE.

Witnesses:

M. B. ODooHnRTY, N. L. LINDOP.