US849335A

US849335A - Electric dental furnace.

Info

Publication number: US849335A
Application number: US29736706A
Authority: US
Inventors: Louis Markwitz
Original assignee: Individual
Current assignee: Individual
Priority date: 1906-01-22
Filing date: 1906-01-22
Publication date: 1907-04-02
Anticipated expiration: 1924-04-02

Description

No 849,335. PATENTED APR. 2, 1907.

L. MARKWITZ.

ELECTRIC DENTAL FURNAGE.

APPLICATION FILED JAILZZ, 1906.

R SHEETS-SHEET l.

wmdde:

. M FLMW PATENTED APR. 2, 1907.

L. MABKWITZ. BLEGTRIC DENTAL FURNACE.

APPLICATION FILED JAILZZ, 1906.

3 SHEETSSHE-ET 9 -No. 849,835. PATENTED APR. 2, 1907.

' -L. MARKWITZ.

ELECTRIC DENTAL FURNACE.

APPLICATION FILED 1111.22, 1906.

witnesses:

UNITED STAT-ES PATENT osrion.

LOUIS MARKWITZ, or SAN FRANCISCO, oALiEonnni. v

su-zormc DENTAL FURNACE.

To all whom it may concern.-

Be it known that 1, Louis. MAnKwrrz,a citizen of the United States, and a resident of the city of San Francisco, county of San;

Francisco, and State of California, have in vented a new and useful Improvement in 'out and then, of course,' requ1res immediate,

repair, and it is therefore desirable'that the arrangement of the parts besuch that the re pair of the vplatinum wiring can be immediately made when necessary, and that it will take but a few minutes. To this end the parts ofv myfurnace are arranged and com ined as illustrated in the drawings. In the latter, Figure 1. representsa general view in perspective of my furnace. Fig. 2 is a longitudinal section about centrally taken. Fig. 3 is a cross-sectionon a line a; m of Fig. '2.

"Fig. 4 is a'front end perspective of the muflie.

Fig. 5 is a perspective detail of the two-part heat resisting jacket of the muffie. -Fig.,,6 is a perspective detail of the outer casing of my furnace; and Fig. 7 is a to "view or plan of my'furnace, also showing t e position of the resistance-coils in broken outline.

The numerals designate the partsreferred to. s a

My furnace comprises an exterior casing, of cast-iron, 1,-consisting of two parts. 2 3, (see Fig. 6,) the former including the bottom 4 and the front wall and the latter includingthe side walls, roof, and back wall 6. g It is to be noted that thetwo parts are siegarableand. may be fastened together, as' trated" in Fig. 6 and the-sectionalviews, Fig.2 and 3.

Whenarranged together, the "side walls. and v the back of the removable part 3 rest on the bottom 4.

To secure the parts in place, the bottom 4 is provided with a'vertical flange-plate 7 attherear end, having two threaded holes 58, (See '1 Fig. 6, which to receive screws 10,-ins'ert ed through corresponding holes 9 in the base Specification of Letters Batent. A'oplicationfiled January 22, 1906. seam. 297,367.

Po t 16, hich cents, approximately.

made ofivulcaniz'ed rubber, which is; adjust Thfro, t wall" Batented April 2, 1907.

i of the rear wall portion 6. The bottom 4 is also made with a projecting hearth-plate 11 andlegs 12. I 7

Within the outer casing is placed a heatresisting jacket 19, made of fire-clay and silex or 0t er suitable material."' Said jacket is made in two arts 19 19*, so asto be readily separated. ithin the jacket- 19is placed the mufile 20, also made of-heat-resisting material. On the exterior of'the muffle 20 are provided spirally arranged' grooves 21,

in which is wound the platinum wire 22, one

end of which wire, 22,, is leddownward through grooves'on the rear exterior face of the muflie, as isshown in broken line in Fig. 3. The casing 1. rests on aresistance or rheostat box 13, provided with a usual circuit-switch 14, also a resistance switch 1 .3 to adjust the degree of resistance. and binding to connect the GiIfCHlt-\ wires. 1

The resistance-box ,is

17 are preferably arranged as shown in Fig. 7, the idea being to leave ample room or space at the center'of box, so as to make it convenient to detach the platinum-wire ends when required. The two ends 22 of the platinum wire 22 areleddownward from the muffle through apertures thereforprovided in the encompassingjpa'rt's and are connected with the coils of'the resistance-box.

From theforegoingflescription the convenience of the arrangement of-my furnace\ o is now apparent. Incase of aburn-out it is the work of a moment to remove the screws 9 10, liftoff. the upper part 3 of the outer casing, next to lift ofi the'upper. art of the jacket 19, so as to expose the mu e20, then to re air the wire windings-of the latter,.and finally to reassemble the parts. This repair can be made in from five to fifteen minutes and at the nominal cost of from. five .to ten To render the adjustment of the resist ance swi-tch'15 convenient when desiring to operate'iwithin' i afl'predetermined j degree of resistance, Iflprovlde aremovable', tip 26,

. 5 able 'to any convenient point of the resist ance-switch,

The -'cirouit-switch 14 is preferably placed on the left side, 'asshown, so as to leave a;

space ,elear on the right side on which to my the instruments being used, I

,rfof. th har s g h s. an-

convenientlyniade Wltll a marble" top, and the resistance-coils openin 5 leading into the muffle 20, and the front end of the roof of such outer casing is made with a slot 24,in which to slide a door 25, made of a sheet of mica.

I claim 1. In an electric furnace, the combination comprising a m'uflle provided with corrugations or grooves on its exterior surface arranged to receive a winding of wire; a jacket of earthy non-heat-conducting material, encompassing said muffle, and made in two separable parts, and an outer metal casing also made of two separable parts, and provided with means for fastening :the same together; the front wall of said outer casing being made with an opening leading into the mufile, and provided with a suitable slidingdoor to close said opening. I

2. In an electric furnace, the combination comprising a muffle provided with corruga tions or'grooves, on its exterior surface, arranged to receive a winding of Wire, a jacketof earthy nonheat conductingmateri-al,..cn compassing said muffle and consisting'of two horizontally-separable parts as 19, '19" and an outer metal casing also madcof two sepa-- rable parts, and provided with-means for fastening the same together; the front wall of said outer casing being made with an opening leading into the vmilfile, and provided with a suitable sliding door .to close said opening. 3. In an electric furnace, tl'lGCOIHlJlHfltlOII comprising a muffle provided. with corrugations or grooves on its exterior surface arranged to receive a winding of wire, a jacket of earthy non-heat-conducting' material, encompassing said muffle, and made in two separable parts, an outer metal casing made of two integral parts, one consisting of the bottomand the front end Wall, and the other consisting of an arched roof, the side walls and the rear end wall; the frpnt wall being made with an opening leading into the muffle, and provided with a suitable slidingdoor to close said opening; and means for fastening the two parts of the outer casing after assembling the parts.

4. In an electric furnace, the combination comprising a muffle provided with corrugations or grooves on its exterior surface ar ranged to receive a winding of wire, a jacket of eai'tliy non-hea't-conducting material, encompassing said muffle, and made in'two separable parts, an outer metal casing made of two parts, one consisting of the bottom and the front end wall and, the other consisting of an arched roof, the side walls and the rear end Wall, the front wall being made with an opening leading into the muffle, and providedwith a sliding door to close said opening; aflange-plate on the rear end of the bottom part of such outer casing, and means for locking the rear end wall of the outer casing thereto, to hold the parts together.

5: An electric furnace comprising a muffle provided with corrugations or grooves on'its exterior surface arranged to receive a wii1ding of wire, a jacket of earthy non-heat-conducting material, encompassing said muffle and consisting of two horizontally-separable parts as 19, 19, an outer metal casing made of two parts, one consisting of the' bottom and the front end Wall, and the other consisting of an arched roof, the side Walls and .the rear end wall; the front wall being made for locking the rear end wall of the outer case consisting of a rheostat or resistance box, the

coils of which are arranged in groups rear- Ward and forward of the center, so as to leave aspace between said groups for the purpose specified; means for adjusting the rheostat, an outer metal casing, mounted on said base, said casing consisting of two parts 2, 3 one comprising the bottom and the front end wall, the latter being made with a door-opening, and the other part of sai l"casing comprising an arched roof, the side walls, and the rear end wall, the roof portion being made with a-slot 24; a door of transparent material inserted in said slot to close the opening of the front wall, means for fastening the two parts of the outer casing together; a muffle provided with corrugations or grooves on its exterior surface, and having a winding of wire lying in said grooves electrically connected with the rheostat; and an interme} diate jacket, of earthy non-hea't-conducting material,encompassing said muffle and consisting of two separable parts, as 19, 19.

In testimony whereof-I have hereunto affixed my signature in the presence of. two witnesses.

LOUIS MARKWIT-Z.