US2386260A - Mounting for electric arc furnace electrodes - Google Patents

Description

Oct. 9, 1945. w, PAYNE 2,386,260

MOUNTING FOR ELECTRIC ARC FURNACE ELECTRODES Filed Sept. 16, 1943 Patented Oct. 9, 1945 MOUNTING FOR ELECTRIC ARC FURNACE ELECTRODES Willlam Harvey Payne, La Grange, 111.

Application September 16, 1943, Serial No. 502,650

11 Claims.

This invention is directed to the structure of the supporting arm which carries the electrode and particularly to the means provided for clamping the electrode and the fluid pressure mechanism for actuating the clamp. The invention also relates to the bus bar in its coacting relationship to the members of the clamping group and to the general arrangement of the apparatus as a whole. Further details will appear from the description of the invention in conjunction with the accompanying drawing wherein- Fig. 1 is a plan view in half section partially broken away; and

Fig. 2 is an elevation in vertical half section partially broken away.

The structure as a whole is carried by an elongated box-like supporting arm I rectangular in cross section and having side walls II, a top wall 12 and a base wall I3. The walls at the forward end terminate in a flange l4, reenforced at the bottom by a rearwardly tapering base plate l5. The flange provides a broad contact face for the attachment of a head yoke ii of chambered construction comprising spaced inner and outer walls I! and I8 and closed at top and bottom to provide an enclosure for the circulation of water or other suitable coolant.

The head yoke is shaped to provide outwardly diverging shoulder portions l8 terminating in "straight parallel armv sections 20 connected by an outer bridge section 2| extending at right angles to the arms, thus defining a space of right angular formation at its outer corners and of convergent formation at its inner side which latter is underlaid by a floor plate 22 having a concave outer edge 23 which lies slightly above the plane of the base plate l5.

The inner ends of the head yoke are secured (preferably by welding) to a flange plate 24 which registers with the flange l4 and is secured thereto by bolts 25, thus providing a rugged support for the weight of the electrode 28 which extends vertically through the head yoke.

Above the supporting arm are located two pairs of copper bus bars 21 (one pair being omitted in the figures) which are held in parallel spaced relation by forward and rear clamps 28 and 29, one of the bars of each pair at the rear end 30 being offset to contact the other and the ends being provided with apertures 3| to provide connections for the current cables. The forward portions of the two pairs or bus bars diverge in substantial reg ter with the diverging shoulder portions of e head yoke but on a higher level and theparallel ends 33 are brought together in register with the arm sections so that the space subtended between the bus bars will align with the space subtended by the underlying yoke.

The corner angles thus afforded by the yoke provide sockets for the reception of fixed contact blocks 34 of conductive material which are beveled on their inner faces 34a to make tangent contact with the wall of the electrode. The blocks extend from the base of the head yoke to the upper edge of the ends 33 of the bus bars and are secured to the latter by screw bolts 35 and to the former by screw bolts 36.

The electrode is clamped against the contact blocks by the action of a clamping block 31, the acting face 38 of which is channeled to closely embrace the cylindrical surface of the electrode on each side of a center recess 39. The clamping block on its rear side is provided with a tubular socket 40 having its upper wall extended to provide an ear 4| apertured to receive a pin 42 which somewhat loosely units the block to the forward end of a tubular piston rod 43 whose opposite end is fitted around a stem 43a extending axially from a piston. Through the piston and stem is a small diameteraxial passageway 44a providing communication between the interior of the tubular piston rod and the space beyond. the piston.

The rear end of the frame is provided with a flange 44b which registers with a flange 45 on a cylinder 46 provided on its head 41 with brackets 48 which carry the clamp 29 for holding the bus bars in elevated position.

Air or other fluid under pressure is admitted through pipe 49 to a valve casing 50 enclosing a plug 5| having channels 52 and 53 for a fourway valve. A pipe 54 wherein is interposed a normally closed solenoid operated check valve 55 leads through the cylinder head to admit pressure behind the piston. Pipe 56 leads from the forward end of the cylinder back to the valve casing, and an exhaust pipe 5! stands opposite the admission pipe 49. With the valve plug turned to the position shown in Fig. 2, fluid under pressure is admitted from the pipe 49 through the groove 52, pipe 54, and check valve 55 to the head of the cylinder to advance the piston and force the separated ends of the clamping block flrmly against the inner side of the electrode and against the resistance of the two spaced contact blocks 34, thus affording four lines of contact for clamping the electrode and providing four contact areas for the flow of the current.

During this adjustment, fluid in advance of the.

piston is exhausted through pipe 58, groove. 53 and exhaust pipe 51, while the check valve 55 serves to block the escape of pressure from the cylinder even though the pressure in the supply line should be reduced. 4

To release the electrode the valve plug is turned through 90 which establishes a pressure line from supply pipe 49 through channel 53 and pipe 58 to the cylinder at a point adjacent the forward side of the piston, while opening an exhaust passageway through the pipe 54, valve 55 (when actuated to open position), channel 52 and exhaust pipe 51.

The clamping block 31 is connected with the bus bars through a slightly flexible, bowed, copper conductor bar 58, the rear end of which is bolted to the clamp 28 while the forward downturned end 59 is fastened by screw bolts to the clamping block so that an unimpeded flow of current will be maintained both to the clamping block and-to the two contact blocks. Forward and rear clamps 60 and BI serve to rigidly secure the frame to a carrier plate 62 reinforced by ribs 63, which carrier plate is supported upon a vertically adjustable standard of any suitable char* acter, which is not shown and which forms no part of the present invention. In order to provide the necessary insulation, mica sheaths 64 may be interposed within-the clamps 29, 60 and GI, the sheaths within the clamp 29 being surrounded by shells 65 of non-magnetic material.

In operation, with pressure admitted behind the piston, the clamping block will be advanced by a straight line, centrally directed thrust, and

being somewhat loosely connected to the thrust rod will seat itself firmly and evenly against the inner side of the electrode, thus forcing the same tightly against the laterally disposed forward contact blocks, so that the electrode will be firmly clamped in position and will be so held until pressure is released from the piston and the clamping block is retracted.

The heavy forward thrust of the clamping block is firmly resisted by the structure of the frame and by the formation of the head yoke which isadmirably adapted to resist such thrusts and at the same time afford the necessaryv strength and rigidity to carry the weight of the electrode at a point distant from the mounting for the arm, while affording extended socket mountings for the contact blocks and a support for the bus bar elements.

The arrangement of the bus bar and its bowed connection with the clamping block afford the necessary flexure to permit the slight degree of movement required in setting and retracting the clamping block while the general structure of the apparatus is one which permits the circulation of water or other coolant to counter-act the effects of the high degree of heat to which the structure is subjected. When the piston is under pressure to clamp the electrode, the gaseous medium at the end of the cylinder is free to seep slowly through to the interior of the tubular piston rod to a point forwardly of the piston, thereby to increase the storage capacity for air to operate the piston for the maximum length of time in case of external air failure.

I claim:

1. In combination with a furnace electrode, a mounting including an elongated supporting arm, carrying at its outer end a head yoke open through aseasco its interior to aflcrd passage for the electrode and having side portions outwardly offset from the arm and connected at their forward ends by a cross bridge portion and affording spaced corner sockets, contact blocks securedwithin said sockets and positioned to bear against laterally sep-- arated areas on the'forward face of the electrode, a cylinder located in the rear of the arm, a piston within said cylinder, a piston rod extending forwardly therefrom through the arm, a clamping block engaged by the forward end of the piston rod and adapted to receive a direct forward thrust therefrom to clamp against the rear side of the electrode, means for controlling the flow of fluid pressure to the cylinder and means for supplying current to the electrode.

2. In combination with a furnace electrode, a mounting including an elongated supporting arm, carrying at its outer end a head yoke open through its interior to aii'ord passage for the electrode and having side portions outwardly offset from the arm and connected at their forward ends by a cross bridge portion and affording spaced corner sockets, conductive contact blocks secured within said sockets and positioned to bear against laterally separated areas on'the forward face of the electrode, a cylinder located in the rear of the arm, a piston within said cylinder, .8. piston rod extending forwardly therefrom through the arm, a conductive clamping block engaged by the forward end of the piston rod and adapted to receive a direct forward thrust therefrom to clamp against the rear side of the electrode, means for controlling the flow of fluid pressure to the cylinder and bus bar means carried by the arm and having members connected with the contact blocks and with the clamping block respectively. 1

3. In combination with a furnace electrode, a mounting including an elongated supporting arm, carrying at its outer end a head yoke open through its interior to afford passage for the electrode and having side portions outwardly offset from the arm and connected at their forward ends by a cross bridge portion and affording spaced corner sockets, conductive contact blocks secured within said sockets and positioned to bear against laterally separated areas on the forward face of the electrode, a cylinder located in the rear of the arm, a piston within said cylinder, a piston rod extending forwardly therefrom through the arm, a conductive clamping block engaged clamp against the rear side of the electrode,

means for controlling the flow of fluid pressure to the cylinder and bus bar means carried by the arm and providing members diverging at their outer ends to make connection with the contact blocks and a centrally disposed bowed flexible member connecting with the clamping block for supplying current to the electrode.

, 4. In combination with a furnace electrode, a mounting including an elongated supporting arm, carrying at its outer end a head yoke open through its interior to afford passage for the electrode and having side portions outwardly of!- set from the arm and connected at their forward ends by a cross bridge portion and affording spaced corner sockets, contact blocks secured within said sockets and positioned to bear against laterally separated areas on the forward face of the electrode, pressure the rear of the arm, a thrust member connected with said pressure actuated means and extending actuated means located in forwardly therefrom through the arm, a clamping block engaged by the forward end of the thrust member and adapted to receive a direct forward thrust therefrom to clamp against the rear side of the electrode, means for controlling the flow of fluid pressure to the pressure actuated means and means for supplying current to the electrode.

5. In combination with a furnace electrode, a mounting including an elongated supporting arm, carrying at its outer end a head yoke open through its interior to afford passage for the electrode and having side portions outwardly offset from the arm and connected at their forward ends by a cross bridge portion and affording spaced corner sockets, conductive contact blocks secured within said sockets and positioned to bear against laterally separated areas on the forward face of the electrode, pressure actuated means located in the rear of the arm, a thrust member connected with said pressure actuated means and extending forwardly therefrom through the arm, a conductive clamping block engaged by the forward end of the thrust member and adapted to receive a direct forward thrust therefrom to clamp against the rear side of the electrode, means for controlling the flow of fluid pressure to the pressure actuated means and bus bar means carried by the arm and having members connected with the contact blocks and with the clamping block respectively.

6. In combination with a furnace electrode, a mounting including an elongated supporting arm, carrying at its outer end a head yoke open through its interior to afford passage for the electrode and having side portions outwardly offset from the arm and connected at their for- Ward ends by a cross bridge portion and affording spaced corner sockets, conductive contact blocks secured within said sockets and positioned to bear against laterally separated areas on the forward face of the electrode, pressure actuated means located in the rear of the arm, a thrust member connected with said pressure actuated means and extending forwardly therefrom through the arm, a conductive clamping block engaged by the forward end of the thrust member and adapted to receive a direct forward thrust therefrom to clamp against the rear side of the electrode, means for controlling the flow of fluid pressure to the pressure actuated means and bus bar means carried by the arm and providing members diverging at their outer ends to make connection with the contact blocks and a centrally disposed bowed flexible member connecting with the clamping block for supplying current to the electrode.

'7. In combination with a furnace electrode, a mounting therefor, including an elongated supporting arm, a pair of laterally spaced contact blocks adapted to bear against the forward face of the electrode on opposite sides of the center of the face, socket means carried by the arm for socketing said contact blocks, a clamping block adapted to bear against the middle portion of the rear face of the electrode, pressure actuated means carried by the arm and including a member positioned to exert a direct forward thrust against the clamping block to clamp the electrode between the clamping block and the contact blocks, means for controlling the flow of fluid pressure and means for supplying current to the electrode.

8. 1n combination with a furnace electrode, a

mounting therefor, including an elongated supporting arm, a pair of laterally spaced conductive contact blocks adapted to bear against the forward face of the electrode On opposite sides of the center of the face, socket means carried by the arm for socketing said contact blocks, a conductive clamping block adapted to bear against the middle portion of the rear face of the electrode, pressure actuated means carried by the arm and including a member positioned to exert a direct forward thrust against the clamping block to clamp the electrode between the clamping block and the contact blocks, means for controlling the flow of fluid pressure and bus bar means carried by the arm and providing laterally divergent members connected respectively with the contact blocks and a centrally disposed flexible member connected with the clamping block.

9. In combination with a furnace electrode, a mounting including an elongated supporting arm carrying at its outer end a head yoke open through its interior to afford passage for the electrode and having side portions disposed outwardly of the arm and connected at their forward ends by a cross bridge, spaced means secured to the yoke adjacent opposite ends of the bridge and positioned to bear against laterally separated areas on the forward face of the electrode, a piston mechanism located to the rear of the arm and provided with a rod extending forwardly parallel with the arm, a clamping block engaged by the forward end of the rod adapted to receive therefrom a direct forward thrust to clamp against the rear side of the electrode, means for controlling the flow of fluid pressure to the piston mechanism, and means for supplying current to the electrode.

10. In combination with a furnace electrode, a mounting therefor, including an elongated supporting arm, conductive contact means supported from the arm adapted to bear against the forward face of the electrode, a conductive clamping block adapted to bear against the rear surface of the electrode, means carried by the arm and including a, member positioned to exert a direct forward thrust against the clamping block to clamp the electrode between the clamping block and the forward contact means, means for imparting a forward thrust thereto, and bus bar means carried by the arm and providing laterally divergent members connected respectively with the forward contact means and a flexible conductor bar connected with the clamping block.

11. In combination with a furnace electrode, a mounting therefor, including an elongated supporting arm, conductive contact means supported from the arm adapted to bear against the forward face of the electrode, a conductive clamping block adapted to bear against the rear surface of the electrode, means carried by the arm and including a member positioned to exert a direct forward thrust against the clamping block to clamp the electrode between the clamping block and the forwardcontact means, means for imparting a forward thrust thereto and bus bar means carried by the arm and providing laterally divergent members connected respectively with the forward contact means anda centrally disposed conductor bar connected at its rear end with the bus bar and having its forward end downtumed and connected with the clamping block.

WILLIAM HARVEY PAYNE.

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