US2303892A - Electrode clamp and support - Google Patents

Description

Dec. 1, 1942. w. E. MOORE 2,303,392

ELECTRODE CLAMP AND 'SUPPORT Filed March 16, 1940 2 Sheets-Sheet .l

w. E. MOORE ELECTRODE CLAMP AND SUPPORT Dec. 1,1942.

2 Sheets-Sheet 2 Filed March 16, 1940 g I a W? WillimEMOOre Patented Dec. 1, 1942 UNITED STATES P TENT OFFICE ELECTRODE CLAMP AND SUPPORT William Enoch Moore, Pittsburgh, Pa., assignor to Delaware Engineering Corporation, Wilmington, Del.

Claims.

My invention relates to improvements in electric arc furnaces, and more particularly to electrode supporting and operating mechanism therefor.

An important object of the present invention is to provide an electrode supporting mechanism which will provide a large electrical contact surface to engage the electrode.

Another object of the invention is the provision of an electrode supporting structure which is effectively cooled to prevent overheating of all of its parts.

A further object of the invention is to provide an electrode clamping mechanism which will securely hold the electrode against slipping and which will not adhere to the electrode through burning or the like.

Still another object of the invention is the provision of an electrode supporting mechanism which is of simple and inexpensive construction and which is efiicient and durable in use.

Other objects and advantages of the invention will be apparent during the course of the following description.

In the accompanying drawings, which form a part of this specification and wherein the numerals designate the parts throughout,

Figure 1 is a top plan view of an electrode supporting structure embodying this invention,

Figure 2 is a side elevation thereof,

Figure 3 is an end elevation of the electrode clamp, looking from the electrode arm toward the contact end of the clamp,

Figure 4 is a top plan view of the clamp ring,

Figure 5 is a sectional view therethrough taken on the line 5--5 of Figure 4,

Figure 6 is a sectional view on the line 6-6 of Figure 4,

Figure 7 is a top plan view of the clamping wedge,

Figure 8 is a rear elevation thereof, and,

Figure 9 is a detail longitudinal sectional view through the wedge guide and support. 1

In the drawings, wherein for the purpose of illustration is shown a preferred embodiment of the invention, the numeral it designates an electrode adapted to extend through the roof of an electric arc furnace. Electrodes of this type are supported from electrode columns disposed at one side of the furnace, and are moved vertically on the column when a stationary column is employed or move vertically with the column when a rise fall type of electrode column is employed. A suitable horizontal arm is connected at one end to the electrode column and is provided at its other end with a clamp to engage the electrode. The present invention is directed to the construction and operation of this electrode clamp and arm.

In Figures 1 and 2 of the drawings, the invention is shown for illustration as applied to the stationary type of electrode column II on which a cross-head structure I2 is slidably mounted for vertical movement. Suitable rollers l3 are carried by the cross-head to engage the column, and these rollers are preferably adjustable toward and away from the column. A split, hollow clamping sleeve I4 is carried by the crosshead I2 and is preferably formed integrally therewith. A tubular electrode arm l6 telescopes at one end with the clamping sleeve l4 and is adjustably secured therein by means of clamping bolts ii. A suitable layer of insulation material i8 is disposed between the clamping sleeve I4 and the tubular arm Hi to completely insulate the electrode arm 16 from the clamping sleeve [4, cross-head l2 and column II. The end of the arm 56 adjacent electrode IE1 is closed by a metal plate I9 which extends beyond the sides of arm 56 to form a flange to which the electrode clamp may be bolted. The other end of arm 16 is also closed to permit the circulation of a cooling fluid through the hollow arm. The electrode clamp body 29 is bolted to the flange formed by plate 19, by means of suitable bolts 2|. A contact shoe 22 is bolted between the machined contact end of the electrode clamp 20 and electrode arm I6, extending thereabove and being provided with bosses 23 above the electrode arm for connection to the ends of bus pipes 24. The bus pipes 24 are extended back around the cross-head l2, passing through and beyond suitable insulated clamps 25 carried by a bracket 26 on the rear of cross-head l2. Suitable flexible water tubes 21 and flexible electrical conductors 28 are connected to the ends of the bus pipes 24 behind the clamps 25. v

A fluid tube 29, which may be flexible if desired, connects the interior of the hollow electrode arm with one of the bus pipes 24 so that a cooling medium such as water may be circulated through the arm to cool the clamp, contact shoe 22, arm l6 and insulation [8. It will be noted that the insulation l8, in addition to being water cooled, is disposed at a substantial distance from the heat adjacent the electrode. A suitable pipe 30 connects the electrode clamp with the other bus pipe 24 while another pipe 3| connects the electrode clamp with the hollow arm It. It will be seen that a cooling medium is circulated through the bus pipes, hollow arm and clamp.

The body or electrode contact shoe 2B of the electrode clamp is of high electrical conductivity material such as copper and extends through an arc of substantially 145. lhe body of the clamp is extended vertically a substantial distance above and below the electrode arm as seen in Figure 2 to provide a large contact area to engage the electrode. A flame shield 32 comprising a yoke shaped strap of heat resisting steel or other suitable material having relatively higher electrical resistance, is joined at its ends to the opposite sides of the clamp body completes the circle of the electrode clamp. The vertical Width of the shield 32 is about one-half that of the clamp body 23.

Cooling coils 33 are of steel cast into the body 23 of the clamp and extending throughout the circle formed by the shield 32, being secured to the inner wall of the shield 32. A steel wedge receiving channel or wedge guide 33 is secured to the coils and flame shield by welding or the like at a point diametrically opposite the center of the body of the clamp. The side edges 34 of the channel 33 are turned up to provide a trough to receive and guide the wedge, as seen in Figures 4, 6 and 9, while a lip 35 is bent over the top of coils 33 and shield 32. The coils 33 and shield 32 have their upper portions extended out beyond their lower portions adjacent the wedge channel 23' to produce a downward taper for accommodating the wedge.

The electrode wedge comprises an arcuate body portion 36 wider at its top than at its bottom and having its electrode engaging surface provided with upwardly extending ratchet teeth 3'! to dig into the surface of the electrode so that the wedge will firmly engage the electrode and be tightened by any downward pull of the electrode. A wedge rib 38 is formed on the back of the wedge body 36 and tapers from top to bottom to engage the wedge channel 33' and force the grooved face of the wedge into firm wedging engagement with the electrode 10. extension 33 is formed at the top of the wedge, extending rearwardly therefrom. A hook flange or finger 40 depends from the rearward edge of extension 39. When the wedge is dropped into the channel 33, as when the electrode is removed, the hook finger 40 drops on the outside of shield 32 to hold the wedge and prevent its falling into the furnace.

The rear surface of the wedge rib 38 is provided with two adjacent vertical rows of notches 4|, 5;

the notches of each row being staggered, to be engaged by a lever or pinch bar 42 shown on Figure 5 for prying up and removing the wedge. The notches 4| are staggered to provide a close spacing thereof.

By reference to Figures 1 and 4 it will be seen that the coils 33 and shield 32 are spaced from the electrode which is engaged only by the clamp body 20 and wedge 36. The wedge forces the electrode into firm engagement with the conducting clamp body. Due to this firm engagement and the extensive contact surface of the high conductive clamp body, a good electrical contact is produced. The high conductivity clamp body conducts the current to the electrode while the relatively higher resistance of the steel shield, coils and wedge limits the amount of current carried by the wedge. This high resistance of the wedge carrying portion of the clamp ring avoids the tendency of the electrode to burn to the wedge or the A horizontal wedge to the wedge channel, a disadvantage found in the usual wedge clamps.

The ring formed by the coils 33 and shield 32 is elongated as well as tapered opposite the clamp body 20 to accommodate the wedge. The circulation of a cooling medium through the arm 16 and coils 33 effectively cools the insulation [8, arm [6, contact shoe 22, clamp body 20, flame shield 32, wedge channel 33 and the wedge 36. The grooved surface of the Wedge prevents slipping of the electrode in the clamp while the notches 4| permit easy removal of the wedge.

The clamp of the present invention is easily manufactured, is simply and rapidly operated, insures a good electrical contact without overheating of any of its parts and the wedge will not burn to the electrode. Due to the provision of the finger 43, the wedge cannot drop into the furnace.

While I have shown and described the preferred embodiment of the invention, various changes in the size, shape and arrangement of parts may be resorted to without departing from the spirit of my invention or the scope of the subjoined claims.

Having thus described my invention, what I claim and desire to protect by Letters Patent is:

1. For use in an electric furnace having an electrode, an electrode clamp and supporting mechanism comprising an arcuate clamp body of high electrical conductivity material adapted to engage a portion of the circumference of the electrode, a wedge guide disposed in spaced relation to said clamp body, means connecting the wedge guide and clamp body, and a wedge slidably received in said wedge guide and adapted to engage a second portion of the circumference of the electrode and force it into engagement with the clamp body, the wedge, Wedge guide and connecting means havin a relatively higher electrical resistance than the clamp body to limit the amount of electric current carried by the wedge and a lower coefiicient of expansion.

2. For use in an electric furnace having an electrode, an electrode clamp and supporting mechanism comprising an arcuate clamp body of high electrical conductivity material adapted to engage a portion of the circumference of the electrode, a wedge guide disposed in spaced relation to said clamp body, means connecting the wedge guide and clamp body, a wedge slidably received in said wedge guide and adapted to engage a second portion of the circumference of the electrode and force it into engagement with the clamp body, the wedge guide and connecting means having a relatively higher electrical resistance than the clamp body to limit the amount of electric current carried by the wedge, a cooling pipe passing through the clamp body, and having surface contact with the wedge guide and the connecting means, and means to circulate a cooling medium through said pipe to cool the clamp body, wedge guide, connecting means and wedge.

3. For use in an electric furnace having an electrode, an electrode clamp and supporting mechanism comprising an arcuate clamp body of high electrical conductivity material adapted to engage the electrode, an annular cooling pipe coil having a portion of its length embedded in said clamp body, said clamp body and cooling coil cooperating to form an electrode receiving ring, a wedge guide carried by said cooling coil at a point diametrically opposite the clamp body, a wedge slidably received in said wedge guide and adapted to engage the electrode and force it into "Wedge, wedge guide and cooling coil having a relatively higher electrical resistance than the clamp body to limit the amount of electric current carried by the wedge, and means to conduct electric current and a cooling fluid to said clamp body.

4. For use in an electric furnace having an electrode, an electrode clamp and supporting mechanism comprising an arcuate clamp body of a material having high electrical conductivity and adapted to engage the electrode, an annular cooling pipe coil having a portion of its length embedded in said clamp body, said clamp body and cooling coil cooperating to form an electrode receiving ring, a wedge guide carried by said cooling coil at a point diametrically opposite the clamp body, a wedge slidably received in said wedge guide and adapted to engage the electrode and force it into intimate engagement with the clamp body, a flame shield secured to said clamp body and cooling coil; the wedge, cooling coil, flame shield and wedge guide having a relatively higher electrical resistatnce than the clamp body to limit the amount of current carried by the wedge, means to conduct electric current to the clamp body, and means to circulate a cooling medium through the cooling coil.

5. For use in an electric furnace having an electrode, an electrode clamp and supporting mechanism comprising an arcuate clamp body of a material having high electrical conductivity and adapted to engage the electrode, an annular cooling pipe coil having a portion of its length embedded in said clamp body, said clamp body and cooling coil cooperating to form an electrode receiving ring, a wedge guide carried by said cooling coil at a point diametrically opposite the clamp body, a wedge slidably received in said wedge guide and adapted to engage the electrode and force it into intimate engagement with the clamp body, a flame shield secured to said clamp body and cooling coil; the wedge, cooling coil, flame shield and wedge guide having a relatively higher electrical resistance than the clamp body to limit the amount of current carried by the wedge, means to conduct electric current to the clamp body, and means to circulate a cooling medium through the cooling coil, said clamp body being extended vertically a substantial distance above and below the cooling coil and flame shield to provide a large area to contact the electrode.

6. For use in an electric furnace having an electrode, an electrode clamp and supporting mechanism comprising an arcuate clamp body of high electrical conductivity material adapted to engage the electrode, an annular cooling pipe coil having a portion of its length embedded in said clamp body, said clamp body and cooling coil cooperating to form an electrode receiving ring, a wedge guide carried by said cooling coil at a point diametrically opposite the clamp body, a wedge slidably received in said wedge guide and adapted to engage the electrode and force it into intimate engagement with the clamp body; the Wedge, wedge guide and cooling coil having a relatively higher electrical resistance than the clamp body to limit the amount of electric current carried by the wedge, and means to conduct electric current and a cooling fluid to said clamp body, said wedge having a series of spaced notches on its rear surface to be engaged by a prying lever for removing the wedge,

and the electrode engaging surface of the wedge being provided with transverse serrations.

7. For use in electric furnace having an electrode, an electrode clamp and supporting mechanism comprising an arcuate clamp body of a material having high electrical conductivity and adapted to engage the electrode, an annular cooling pipe coil having a portion of its length embedded in said clamp body, said clamp body and cooling coil cooperating to form an electrode receiving ring, a wedge guide carried by said cooling coil at a point diametrically opposite the clamp body, a wedge slidably received in said wedge guide and adapted to engage the electrode and force it into intimate engagement with the clamp body, a flame shield secured to said clamp body and cooling coil; the wedge, cooling coil, flame shield and wedge guide having a relatively higher electrical resistance than the clamp body to limit the amount of current carried by the wedge, means to conduct electric current to the clamp body, and means to circulate a cooling medium through the cooling coil, said wedge having a series of spaced notches on its rearward surface to be engaged by a prying lever for removing the wedge, and the electrode engaging surface of the wedge being provided with transverse serrations.

8. For use in an electric furnace having an electrode, an electrode clamp comprising an arcuate clamp body, a wedge guide means con necting said guide with said clamp body, a wedge slidably engaging said guide and extending thereabove, said guide, means, and wedge having a higher electrical resistance than the clamp body, said Wedge being adapted to engage the electrode and force it against said clamp body, there being transverse upwardly extending ratchet teeth in the electrode engaging surface of the wedge, and the opposite surface of said wedge being provided with a vertical series of spaced notches throughout a substantial portion of its length adapted to be engaged by a prying lever to remove the wedge from the guide.

9. For use in an electric furnace having an electrode, an electrode clamp comprising a clamp body, a wedge guide operatively connected with said clamp body, a Wedge slidably engaging said guide and extending thereabove, said wedge being adapted to engage the electrode and force it against said clamp body, there being transverse serrations in the electrode engaging surface of the wedge, and the opposite surface of said wedge being provided with a vertical series of spaced notches throughout a substantial portion of its length adapted to be engaged by a prying lever to remove the Wedge from the guide, and a hook member carried by and projecting beyond the upper portion of the Wedge and adapted to engage the guide and limit downward movement of the wedge in the guide.

10. For use in an electric furnace having an electrode and an electrode supporting column, the combination comprising an arcuate electrode contact shoe having a cooling passage therein and a face conformed to the curvature of the electrode, a yoke shaped shield comprising a separate strap of metal having its ends secured to the opposite sides of the shoe, a wedge guide secured to the shield at a position opposite the shoe, an arcuate wedge having one side engaging the guide and another side for engaging the electrode, bus pipes connected to the contact shoe, said bus pipes being arranged one on each side of the column and projecting beyond the column.

11. For use in an electric furnace having an electrode and an electrode supporting column, the combination comprising an arcuate electrode contact shoe having a cooling passage therein and a face conformed to the curvature of the electrode, a yoke shaped shield comprising a separate strap of metal having its ends secured to the opposite sides of the shoe, a wedge guide secured to the shield at a position opposite the shoe, an arcuate wedge having one side engaging the guide and another side for engaging the electrode, bus pipes connected to the contact shoe, said bus pipes being arranged one on each side of the column and projecting beyond the column, said Wedge having ratchet teeth in the electrode engaging side.

12. For use in an electric furnace having an electrode and an electrode supporting column, the combination comprising an arcuate electrode contact shoe having a cooling passage therein and a face conformed to the curvature of the electrode, a yoke shaped shield comprising a separate strap of metal having its ends secured to the opposite sides of the shoe, a wedge guide secured to the shield at a position opposite the shoe, an arcuate wedge having one side engaging the guide and another side for engaging the electrode, a tubular electrode arm for supporting the shoe, a bus pipe connected to the tubular arm, a fluid passage between the arm and the cooling passage of the shoe, a second bus pipe, a fluid passage between the cooling passage of the shoe and the second bus pipe, each of said bus pipes extending from the shoe, to a point beyond the column and passing on opposite sides of the column.

13.'An electrode support for an electric furnace electrode comprising an arcuate electrode contact shoe having a face curved to conform to the curvature of the electrode, a yoke shaped shield comprising a separate strap of metal of lower electrical conductivity than the shoe secured to the opposite sides of the shoe, and forming with the shoe an electrode encircling structure, an electrode guide secured to the shield opposite the shoe, said guide having a downward and inwardly sloped face, and a wedge having one side engaging the guide and another side for engaging the electrode.

14. An electrode support for an electric furnace electrode comprising an arcuate electrode contact shoe having a face curved to conform to the curvature of the electrode, a yoke shaped shield including a separate strap of metal of lower electrical conductivity than the shoe secured to the opposite sides of the shoe, and forming with the shoe an electrode encircling structure, an electrode guide secured to the shield opposite the shoe, said guide having a downward and inwardly sloped face, and a wedge having one side engaging the guide and another side for engaging the electrode, said wedge having ratchet like teeth on the electrode engaging side.

15. An electrode support for an electric furnace electrode comprising an arcuate electrode contact shoe having a face curved to conform to the curvature of the electrode, a yoke shaped shield including a separate strap of metal of lower electrical conductivity than the shoe secured to the opposite sides of the shoe, and forming with the shoe an electrode encircling structure, an electrode guide secured to the shield opposite the shoe, said guide having a downward and inwardly sloped face, and a wedge having one side engaging the guide and another side for engaging the electrode, said Wedge having ratchet like teeth on the electrode engaging side, said guide, and wedge having relatively higher electrical resistance than the shoe.

WILLIAM ENOCH MOORE.

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