US1697188A - Electric-furnace construction - Google Patents

Description

Jan. 1, 1929. J 1,697,188

G. KELLER ET AL swcmc runmcm consmvcwzon Filed May 9, 1927 Patented Jan. 1,1929.

, UNITED STATES PATENT OFFICE.

GO'ITLIEB KELLER, OF BRUGG, AND ERNST W132, 015 BADEN, SWITZERLAND, AS- SIGNORS T0 AKTIENG ESELLSCHAFT BROWN BOVERI & CIE, OF BADEN, SWITZER- LAND, A JOINT-STOCK QOMPAN Y 01 SWITZERLAND.

ELECTRIC-FURNACE CONSTRUCTION.

Application filed Kay 9, 1927, Serial No. 189,877, and in Germany June 7, 1926.

This invention relates to electric furnaces of the melting type and has to do particularly with the construction of means for supporting and adjusting the electrodes, whereby their feed is controlled incident to operation of the furnace.

Thegeneral object of the invention is the provision of an adjustable electrode supporting apparatus which will aii'ord effective insulation between the electrode carrier, which is electrically charged, and the earthed members whereby the carrier is supported and operated. l

Another object is the provision of a construction which will be effective to avoid deterioration of the insulation by heat and wear, and thus aflord reliable protection for the portions of the apparatus which are earthed or which are likely to be touched by persons or other objects.

Other and further objects willbe pointed out or indicated hereinafter, or will be apparent to one skilled in the art upon anunderstanding of the invention or its employment in practice.

In the drawing forming a part of this specification, We illustrate certain arrangements of structure embodying the invention, but it is to be understood that these are susceptible of various modifications in arrangement and detail, withoutdeparting from the scope of the invention indicated in the appended claims.

In said drawing,

Fig. 1 is a diagrammatic illustration in the nature of a sectional elevation of apparatus in which the invention is embodied;

Fig. 2 is a detail inthe nature of a diametrical section of one of the wheels for the carrier 'frame Fig. 3 is a similar section of a modified construction of the frame-carrying wheels;

Fig. 4 is a detail in the nature of a sect-ion of a connection between the electrode-carrying frame and its operating means; and

Fig. 5 is a similar'detail of another form of such connection Considerable difiiculty is ex erienced in preserving proper insulation etween the movable electrode holders ofelectric melting furnaces and the associated portions ofthe apparatus which are earthed or which are easily accessible and likely to be touched by persons or objects in the vicinity of the furnace. These difiiculties arise from the necessity of affording secure support and accurate guidance for the electrodes, which are themselves heavy, and the destructive effects of high temperatures upon the insulating material. The present invention solves the difliculty by a new arrangement of the electrode supporting and operating apparatus, whereby the necessary strength is afforded in the supporting structure, accu-v racy in the guidance of the electrode is maintained, and the insulating material is safeguarded against the destructive ei'fects of the furnace temperatures. The nature of the in-' having flanged wheels 17 which run on and are guided in guide channels 18 supported inan upright position adjacent the furnace by brackets 19. Hydraulic power cylinder 20 constitutes part of the operating means for effecting and controlling the vertical position of the carriage on the guides l8,.and hence the position of the electrode and its feed toward or from the furnace. The piston of the hydraulic cylinder 20 is connected to the carriage by 'a rod 21 and a connection 22. I The cylinder, of course, has pipe connections to other apparatus, such as the means for furnishing and regulating the supply of pressure fluid, so it is highly important thatthe cylinder, as well as the guides 18, be fully insulated from the heavy current supplied to the carrier 14. Heretofore, it has been customary to provide an insulated COllI1C tion between the carrier 14 and the arm 16, or in the latter, for this purpose. When so arranged, however, the insulating material is'then exposed to high temperatures, and also to mechanical pressures, which has frequentlyresulted in the deterioration or breaking down of'the insulation and loosening of the mechanical mounting of the carrier. By the present invention the insulat-.

ing material is removed from the zone of layer of suitable insulating material 24, such as mica. Thus a strong mechanical structure is provided, which is Well qualified to support the carriage, with efiective insulation between the carriage and the guides. The edges of the mica insert are protected by rings of a suitable insulating material, such as bakelite, suitably molded or. othera wise secured against the faces of the wheel members. In the construction as illustrated in Fig. 3, there are provided cooperating hub portions 17 c and 17 having synclinal peripheral faces for clamping cooperation with synclinal inner faces of the rim portion 17 The insulating material 26 is inserted be tween these cooperating faces of the hub and rim members and the'hub member 17 drawn up toward the member 17 by bolts 27, so as to securely clamp the insulating material between the rim and hub members.

Connections for the operating rod and the carriage are illustrated in Figs, 4 and 5. In the construction illustrated in Fig. 4, the operating rod '21 carries a yoke member 28 which is shrunk onto a bushing 29 with an interposed sleeve 30 of strong insulating material, such as mica. The bushing is connected .to the carriage by a stud 31. In this fashion,

the operating mechanism is effectively insulated from the carriage. struction illustrated in Fig. 5, the rod 21 carries a split clamping member 32, which is clamped down on the stud 31by bolts 34, with a'sleeve 35 of insulating material interposed between the clamp and the stud.

With the apparatus constructed in conformity with this invention, therefore, the insulating material is safeguarded against high temperatures and mechanical wear, and

its security and durability thereby materially enhanced, with the result that the grounded portions of the mechanism are afforded better protection against voltage and the electrode is aiforded more accurate guidance and stable support,

'Whatwe claim is:

1. In electric furnace apparatus, in combination, an electrode holder, a carriage for same, a guide on which the carriagetravels, and insulating material between the carriage In the conand guide for preventing transmission of current from the holder to the guide.

2. In electric furnace apparatus, in comwhich the carriage travels, insulating ma-- terial between the carriage and guide, operating mechanism for shifting the carriage on the gulde, and insulating material between the operating mechanism and carriage.

4. In electric furnace apparatus, 1n combination, an electrode holder, a carriage supporting the holder, a guide for the carriage, and wheels on which the carriage travels on the guide. paid wheels having incorporated therein dielectric material insulating the guide from the carriage.

In electric furnace apparatus, in combination, an electrode holder, a carriage supporting same, operating mechanism for shifting the carriage, and a connection between the operating mechanism and carriage whereby movement is transmitted to the latter from the former, said connection haviifg incorporated therein dielectric material insulating the operating mechanism from .the carriage.

6. In electric furnace apparatus, in combination, a carriage for supporting anelectrodc, a guide for the carriage, and a wheel having a hub portion connected to the car- .riage anda rim portion running on the guide and dielectric material insulating the rim portion from the hub portion.

7. In electric furnace apparatus, in combination, a carriage for supporting an electrode, and a guide and operating mechanism having insulated operative connection with the carriage.

8. In electric furnace apparatus, in combination, a vertically extending guide disposed to one side of the furnace, a carriage having an electrode-supporting arm extending from theguide to a position over the furnace, and insulating means between the carriage and guide and operating to guide said carriage for traveling movement on said guide and to insulate said carriage from said guide.

' In testimony whereof we have hereunto subscribed our names this 21 day of April, A. D. 1927, atZurich, Switzerland.

GOTTLIEB KELLER. ERNST WIRZ.

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