US859641A - Electric furnace. - Google Patents

Description

PATENTED JULY 9, 1907.

E. A. GOLBY. ELECTRIC FURNACE.

APPLIOATION FILED NOV.23,1906.

4 SHEETS-SHEET 1.

gill! WlTNESSES: I

g mam PATENTED JULY 9, 1907.

E. A. COLBY.

ELECTRIC FURNACE.

APPLICATION FILED NOV.23,1906.

4 SHEETS-SEEET 2.

ATTORNEY I I 1 I I PATENTED JULY 9, 1907.

E. A. COLBY.

ELECTRIC FURNACE.

APPLICATION FILED NOV.23,1906.

4 SHEETS-SHEET 3.

PATENTED JULY 9, 1907.

13. A. COLBY. ELECTRIC FURNACE.

APPLICATION IILED NOV.23,1905.

4 SHEETS-SHEET 4.

III!!! F ll I hereinafter set forth.

' of asbestos board, in the space To all whom it struction of the induction furnace by renderingthe UNITED STATES p grnn'r orruon.

EDWARD A. COLBY, OF NEWARK, NEW JERSEY, ASSIGNOR TO AMERICAN ELECTRIC FURNACE COMPANY, A CORPORATION OF NEW YORK.

ELECTRIC FURNACE.

' No. 859,641. Specification of Letters Patent.

Applicltiou fil d November 23,1905. Serial No. 288,630.

members 8 and 9 and receive between them the upper laminated frame members 13 and 14. The plates 12 have edge recesses to receive the end pivot pins of earns 15 and 16. Said cams are provided with levers 17 by forcing down which as shown in Fig. 2, the outer ends of the upper members 13, 14 are pressed tightly against the upper ends of the side members 8 and 9.

The inner ends of members 13 and 14 meet directly above the middle frame member or core 18 which extends through the space surrounded by the crucible 1 and bears upon the lower frame member 6. In the upper end of core 18 are recesses to receive dowel pins 19 which enter corresponding recesses on the under side of members 1.3, 14. In the lower ends are similar recesses and dowel pins 19 Bolted on opposite sides of the core 18, are plates 20 which extend upwardly and receive between them the abutting ends of members 13, 14. In said plates are edge recesses similar to'thosc in plates 12, which receive end pivot pins of a similar cam 21, provided with a hand lever 22, which can be brought down to force the inner ends of members 13, 14 tightly against the upper end of the core 18.

It will be seen that by this construction the upper members of the laminated frame of magnetic material may be clamp ed tightly down upon the side and middle members so as to insure close metallic contact. The upper members 13, 14, however, are easily detachable, since the cam pins may readily be taken out from the edge recesses in plates 12 and 20, thus allowing of the removal of the cams and the lifting out of said members from between said plates. The object of making the upper frame member in practically two parts 13, 14 is to facilitate this removal.

From the horizontal section shown in F ig. 3, it will be seen that the laminated core 18 has its laminations of such widths as to form vertical stepped recesses on its exterior. These recesses receive tubes 23 of porcelain, fire clay or other insulating material which prevent contact of the core 18 and the inducing coil 24 which surrounds it.

The inducing coil 24 is preferably a tube of copper, and has its turns of sufficient diameter to permit it to lie in close proximity to the surrounding wall of the crucible. It rests upon a ring 25 of refractory material supported by lower frame member 6 between which ring and the crucible and core there are open spaces for air may concern:

Be it known that 1, EDWARD A. COLBY, a citizen of the United States, residing at Newark, in the county of Essex and State of New Jersey, have invented a certain new and useful Improvement in Electric Furnaces, of which the following is a specification.

' The invention relates to an electric induction furnace of the type set forth in U. S. Lette'rsPatent No. 428,378 granted to me May 20, 1890.

The invention consists in the construction of the frame of magnetic material; also in a tubular inducing coil; also in the devices for holding the coil; also in the insulating blocks disposed between the coil turns and their arrangement; also in the means for establishing liquid circulation and electric circuit in the coil; also in the various combinations more particularly The object of the invention is to improve the conparts more eas'ly'assembled and detached, to improve the inducing coil and its insulation and to provide for effective circulation of refrigerating liquid therein.

In the accompanying drawings-Figure 1 is a top view of my improved induction furnace. Fig. 2 is an elevation show'ng the crucible and its support in vertical section. the line a: .r of Fig. 4. 4 is a side elevation of the coil, core and upper member of the frame. of the same. Fig. 6 shows the arrangement of the coil and separating blocks of insulating material. Fig. 7 is a transverse section of a preferred form of crucible showing the heat insulating covering thereof. Fig. 8 is a top view of the coil terminals showing the mode of connecting them to the electric mains and also to the source of water supply. Fig. 9 shows a side view of the same, the coil tube at its junction with the water supply conduitbeing in section.

Similar numbers of reference indicate like parts.

1 is the crucible in annular form, having the charge receiving chamber 2. Said crucible rests upon the base plate 3 and is provided with a jacket 4, preferably between which and the crucible heat insulating material, such as magnesia may be placed as shown at 5, Fig. 7. The base plate 3 which may be of soap-stone is secured upon the lower member 6 of a frame of laminated magnetic ma-' terial. To the ends of said lower member are bolted circulation.

the vertical members 8 and 9, to which are secured Interposed between the turns of coil 24 are separat flanged plates 10, to the outer faces of the flanges of ing blocks 27, Fig; 6, of refractory insulating material. which are bolted the circular plates 11, which carry Each block has a semi-circular recess in its opposite can be tilted when desired.

. vSaid trunnions are received in any suit- (not shown), so that the entire furnace trunnions 7. able housing The if: ngcd plates 12 extend above the upper ends of blocks are held together slots through which passes in it from the coil 24 Whch coil with them held down upon the ring by means of the plates 28 on opposite sides of core 18. Said plates have flanges 29 on their lower extremities covered beneath with insulating layers 30, which insulating layers rest upon the coil 24. The plates ZSh-ave vertical the bolt 31, which also serves to secure the plates 20 to core 18. Bolt 31 is threaded and provided with a nut, so that it can be loosened to allow plates 28 to be adjustedvertically.

The coil 24 is made tubular in order to admit of Waframe of magnetic material surrounding said cru 'ibic h.-i\'ing a detachable upper member and a detachable Illlt: 1 member extending through said crucible.

4. in an electric furnace of the type settorlh. having a crucible and an inducingcoil. a rectangular frame of magnetic material surrounding said crucible and coil, and means for detachably securing the upper member of said frame to the side members thereof.

In an electric furnace of the type set forth, having an annular crucible and an inducing coil, a rectangular frame of magnetic material surrounding said crucible and coil and having, a middle member extending through said coi and means for detachably securing said upper member (o ter circulation through it for cooling purposes. The the Side and middle members of i mum, electrical iilld WliOl COIIIIGCUO IS 0f he C0 l best (5. In an electric furnace of the type set forth, having an SlIOWIl in Figs. 8 and 9. annular crucible and an inducing coil. a rectangular iraiuc of magnetic material surrounding said crucible and coi and havinga middle member extending through said coil, and an upper member in two parts with their ends tlllli 'w ting above said middle member, means for detachably curing the outer ends of said upper member to the members of said frame and the inner abutting ends to middle member.

7. In an electric furnace of the type set forth, lmvlzu: an annular crucible and an inducing coil, a rectangular frame of magnetic material surrounding said crucible and 32 is a casting having a downwardly turned duct 33, and provided at one end of said duct with a threaded projection to receive the coupling nut 34 for the attachment thereto of the flanged thimble 35 on the end of water conveying hose-36. To the other end of the duct the coil tube 24 is secured by brazing, or in any other convenient way. On said casting is also formed the flat partly circular lug 37 to one face of which is secured by means of the bolt 38 a circular plate 39 integral with the tube 40, in which tube the electrical conductor 41 leading from the source of current is inserted and fastened by any suitable means. A second casting 42, similarly constructed, receives the return hose 43 and return conductor 44. Both castings have side member in contac: with the extremities of the side members of said frame.

frame, alplate 47 of insulating material being interposed. 'For the purpose of conveniently connecting a measuring instrument (not shown) for determining, potential differences at the coil terminals, conducting connected to the castings by the fastening bolts 40. Liquid, therefore, circulates from hose 35 through casting 32 to coil24, to casting 42 and return hose 43, or vice versa.

an annular crucible a rectangular frame of magnetic material surrounding said crucible hava vertically movable upper member and a middle membor extending through said crucible and means for press ing and holding said upper member in contact with the extremities of said middle member and the side members of said frame.

10. In an electric furnace of the type set forth, having a crucible and a removable inducing coil, :1 support, and menus acting on one face of said coil for holding said coil against said support.

11. In an electric furnace of the type set forth, having a crucible and a removable inducing coll, a support below said coil and means for holding said coil down on said support.

12. In an electric furnace of the type set forth, a crucible and a removable inducing, coil, a support said coil and adjustable means for holding said coll upon said support.

12. In an electric furnace of the type herein set forth, having an annular crucible and an inducing coil, :1 rectangular frame surrounding and supporting said crucible and coil and having a middle member extending through said coil and means on said middle member for holding said coil down upon the lower member of said frame.

14. In an electric furnace of the type set forth, an inducing coil having a plurality of turns and separated bodies of refractory insulating material interposed between said turns.

15. In an electric In order more perfectly to prevent heat radiation from the crucible I may form on the under side thereof and below the melting chamber an annular recess 49, and pack it with heat insulating material as shown in Fig. 7.

For the purpose of conveniently disconnecting the coil 24 in order to remove it from the apparatus, I provide detachable couplings 50 in the tube.

In operation the charge to be heated is placed in the crucible chamber 2, and is melted by currents induced is connected with a source of alternating current. The charge when melted may be poured into a mold or ot er receptacle by suitably tilting the furnace, and during the melting operation the furnace may be rocked on its trunnions, if desired.

I claim:

1. In an electric furnace of the type set forth, having an r annular crucible and an inducing coil, a frame of magnetic material surrounding said crucible and coil and having, a detachable member extending through said crucible.

2. In an electric having: below down furnace of the type set forth, an in ducing coil having a plurality of turns and separated bodies of refractory insulating material having recesses to receive the coil conductor and disposed between said In combination with the crucible of an electric induction furnace, an inducing coil having a plurality of turns separated by an air material surrounding and supporting said. crucible and coil and having a detachable middle member extending through said crucible.

3 In an electric furnace of the type set forth, having an annular crucible and an inducing coil, a rectangularsaid space between crucible and core: the said coil being construcied and arranged so that there shall be free air circulation through, outside of and between the turns of said coil.

18. The combination of an electric furnace of a frame of magnetic material, an annular crucible Supported therein, a core in the circular space surrounded by said crucible, an inducing coil disposed in said space between crucible and core and a ring of insulating material supporting said coil and supported by the lower member of said frame. I

19. In an electric furnace of the type set forth, an inducing coil having a plurality of turns and separted bodies of insulating material having recesses to receive the coil conductor, disposed between said turns and superposed in contact to form a vertical column.

.20. In an electric furnace of the type set forth, a support, an inducing coil therein having a plurality of turns, bodies of insulating material having recesses to receive the coil conductor disposed between said turns and super posed in contact to form a vertical column and means acting downwardly in said coil to hold said bodies in contact.

21. In combination with the crucible of an electric in duction furnace wherein the charge forms a secondary circuit, a primary coil in proximity to said crucible, and means for preventing variations in the electrical resistance of said coil due tofheat-radiated from said crucible.

22. The combination with the crucible of an electric in duction furnace wherein the charge forms a secondary circuit, a tubular primary coil in proximity to said crucible and means for establishing a current of cooling medium through said coil.

23. In combination with the crucible of an electric induction furnace wherein the charge forms a secondary circuit, a tubular primary coil disposed in the circular space surrounded by said crucible and means for establishing liquid circulation in said coil.

2-1. In combination with the crucible of an electric induction furnace wherein the charge forms a secondary circuit, a tubular primary coil disposed in the circular space surrounded by said crucible, a core of magnetic material within said coil, and means for establishing liquid circulation in said coil.

25. In an electric furnace of the type set forth, an in 'ducing coil, a support therefor and means for detachably clamping said coil to said support.

26. In an electric furnace of the type set forth, a crucible, an inducing coil, :1 support common to both and means for detachably clamping said coil to said support.

27. In an electric furnace of the type set forth, a

.crucible, an inducing coil, 11 core of magnetic material,

a support for said parts and means for detachably clamp-' ing said coil and said core to said support.

28. In an electric furnace of the type set forth, a crucible and inducing coil, :1 core of magnetic material, a support for said parts and means for detachably clamping said core to said support.

29. In an electric furnace of the type set forth, a crucible, an inducing coil surrounded thereby, a core of magnetic material within said coil and means for removably holding said core in said coil.

30. In an electric furnace of the type set forth, a tubular inducing coil, a support therefor, means of supply of refrigerating liquid and electric current to said coil and means for removably disconnecting said coil from said support. and from said liquid and current supply.

131. In an electric furnace of the type set forth, an inducing coil, a core of magnetic material therein having longitudinal recesses and bodies of insulating material disposed in said recesses and between said coil and said core.

32. In an electric furnace of the type set forth, an inducing coil, a core of magnetic material therein having longitudinal recesses and tubes of insulating material disposed in said recesses and between said coil and said,

core.

33. In an electric furnace of the type set forth, an inducing coil, a core of laminated magnetic material therein and having its laminations of difierent widths to form symetricnlly disposed longitudinal recesses and tubes of insulating material disposed in said recesses and between said coil and said core.

3-1. The combination in an electric induction furnace of a crucible, a terminal of conducting material having a duct, means for connecting a liquid conduit to said duct, means for electrically connecting an electric conductor to said terminal and means for electrically connecting said tubular coil to said terminal and said duct.

35. The combination with a fixed member of an electric induction furnace of a tubular bracket of conducting material, a contact plate integral therewith, an electric conductor, means for connecting said conductor to said contact plate, two conduits, means for connecting a conduit to each end of said tube in said bracket, an nducing coil, and means for connecting one of said conduits to said coil.

36. The combination of a tubular bracket of conducting material, a contact plate therein, pipe connections at each end of said bracket tube, a second contact plate, means for detachably connecting said contact plates and means for securing an electrical conductor to said second contact plate.

In testimony whereof I have aflixed my signature in presence of two witnesses.

/ EDWARD A. COLBY.

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