US589048A - Charles a - Google Patents

Description

(No Model.)

G. A. TIMME. ELECTRIC DENTAL EURNAGE.

No. 589,048. Patented Aug. 31,1897.

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UNITED STATES PATENT EEICE.

CHARLES A. TIMME, OF NE\V YORK, N'. Y.

ELECTRIC DENTAL FU RNACE.

SPECIFICATION forming part of Letters Patent No. 589,048, dated August 31, 1897.

Application filed March 14, 1896.

To all whom t may concern:

Be it known that l, CHARLES A. TIMME, a citizen of the United States, residing in the city of New York, in the'county and State of New York, have invented certain new and useful Improvements in Electric Dental Furnaces, of which the following is a specification.

This invention relates to an improved electric dental furnace which isintended for use in the manufacture of artificial teeth, bridgework, and gums, and in which the high degree of heat necessary for the baking of the articles and the melting of the enamel on the same is produced bythe electric current that is supplied to suitable heating plates arranged in the walls of the muiiie and the invention consists of an electric dental furnace which is composed of an exterior casing of refractory material, removable heating-plates arranged at the interior of the inutile, the plates being independently connected with av suitable source of electricity, so that ditferent degrees of heat can be produced at the interior of the muttle, according to the work to be done in the same.

In the accompanying drawings, Figure l. represents a perspective View of my electric dental furnace. Fig. 2 is a plan view, partly in horizontal section, on line 2 2, Fig. l; and Fig. 3 is a vertical transverse section on line 3 3, Fig. 2.

y Similar letters of reference indicate corresponding parts.

Referring to the drawings, A represents the base of myimproved electric dental furnace, which is made either of refractory material or of suitable metal, and which is provided at its rear part with an upright flange a, that extends along three sides of the base A. A mulile B is supported on the base A and arranged so as to abut against the flange a. rlhe muftle B is made of suitable refractory material, preferably of rectangular shape, and provided at its inside with electric heatingplates C C,which are supported at the top and bottom of the munie and separated from the walls of the same by a layer c of non-conducting material. The electric heating-plates C C are each formed of refractory material, in which a platinum conducting-wire in serpentine form is embedded while the material is Serial No. 583,158. (No model.)

in plastic state. The top and bottom plates may be supported on suitable iianges el d, so as to be readily removed from the muftie for being exchanged or repaired. The side walls may also be provided with similar electric heating-plates D D, as shown in dotted lines in Fig. 23, so that the temperature that is desired to be produced in the muttle can be increased or decreased in whole or at any particular part, according as one, two, or more plates are switched intocireuit. The bottom plate O serves as a support for the objects to be burned in the mut'tle, such as artificial teeth, bridge-work, gums, rbc., made from porcelain and other substances.

B y arranging the electric heating-plates independently of the inutile at the inside of the same, the heat of the same is enabled to act directly on the objects to be burned, while at theV same time the temperature in the mut'tie can be raised or lowered by switching in all or aportion of the plates, or the heat can be applied to one or more sides ofthe objects by switching the upper conducting-plate alone or the side heating-plates, or the upper, side, and bottom plates into the circuit. This arrangement has the advantage that not only the Aheat in the muttle can be easily regulated, but that larger objects, such as artificial gums, can be burned in the muiiie and provided with thicker or thinner coatings of enamel, which can be burned on the objects in avery effective manner.

The front opening of the mutlie is closed by a cover B', which is provided with a free packing of insulating material, said cover beingprovided with exterior stays b, so that it can be supported in contact with the front edges of the mut'tie. The cover B is further provided with a peep-opening h2, closed by a suitable plug b3.

The front part of the 1n ut'tle B is surrounded by two metallic straps ff', of which one is provided at one side with two binding-posts f2 and Vat the opposite side with one main binding-post F, while the second strap is provided at one side with one main binding-post F and at the other side with two bindingposts f". The current is supplied tothe main binding-post F and conducted by the strap f over the binding-posts f2 to the wires of the heating-plates C C', if both are used, or the IOO f2, respectively.

one or the other only, according as either the top or bottom plates alone is used, in which vlatter case the ends of conducting-wires are released from the upper or lower binding-post The current is conducted along the wires embedded in the plates C C/ and heats said plates to incandescence, passing to the binding-postsf3, strap f, and main binding-post F' back to the battery or other source of electricity. By the electric connection of the main wires with the main binding-posts and of the auxiliary binding-posts with the wires in the plates C C any one of the heating-plates can be readily placed in circuit and thereby the required degree of heat produced at the interior of the muffle.

lIn case interior heating-platesare used at the side walls of the mufiie in addition to the top and bottom plates additional binding-posts for the side plates have to be arranged,- to which the ends of the platinum wires are applied, asjffon the stripf,and]C6 andf7 on the conducting-strip f', and which are switched into circuit with the main binding-posts, through which the current is supplied. When the burning of the articles in the muffle is completed, the cover is removed, so that access is given to the articles in the mufiie. In case any one of the heating-plates should become defective it can be readily removed from c the muffle and either replaced by a new heating-plate or repaired by locating the break in the wire and reconnecting the same. By

muffle to the manufacturer for repairs, which is the case when the conducting-wires are embedded in the walls of the muffle itself, in which case it is difficult to locate the break and the use of the muffle rendered impossible until the break has been repaired. This may lead to annoying delays in the work on hand, which is obviated by myilnproved construction, in which the dentist can readily substitute a new conducting-plate for a vdefective plate and continue thereby the use of the muflic.

The baking of the dental plates is effected 5o ata temperature of 3,5000 Fahrenheit or more, and the heating-plates are capable of withstanding such degree of heat.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

In an electric dental furnace, the combination of a inufie composed of refractory material, removable independent heating-plates disposed in the walls of said mufe, and composed of refractory material having conductors embedded therein, two separate conductive straps surrounding said muiiie near its front end, each provided with a plurality of binding` posts for establishing connection with the electric source and with the heatingplates independently of each other.

In testimony that I claim the foregoing as my invention I have signed my name in presence of two subscribing witnesses.

CHARLES A. TIMME.

Witnesses:

PAUL GOEPEL, GEO. W. JAEKEL.

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