US2834824A - Automatic electrode clamping device - Google Patents

Description

May 13, 1958 J. A. vANNosTRAN 2,834,824

AUTOMATIC ELECTRODE CLAMPING DEVICE Filedy May 27. 1957 4 Sheets-Sheet l 'full'.

May 13,' 1958 J. A. VAN NosTRAN 2,834,824

AUTOMATIC ELECTRODE CLAMPING DEVICE 4 She'ets-Sheet 2 Filed hay 27, 1957 l2 L4 l l I lIl'J I I I3 I r INVENTOR.

Juelz 14.VanN0s m1z BY JMJ o Fig. 4 4

v ATTORNEYS May 13, 1958 J. A. VAN NosTRAN 2,834,824

AUTOMATIC ELECTRODE CLAMPING DEVICE Filed May 27,' 1957 4 Sheets-Sheet 3 INVENTOR.

64 Jaz/01rd. VznNasfrem AATTaRNElS May 13, 1958 J. A. VAN Nos'rRAN Y 2,834,824

AUTOMATIC ELE'cTaoDE CLAMPING DEVICE Filed May 27, 1957l INVENTOR.

Jac/Iz Walz/Nash@ BY gwf ATTREKS' 4 Sheets-Sheet 4 Unitd rates arent O assista AUTOMATIC Erncrnonn orar/irme nnvrcs Jack A. Van Nostran, Canton, Ghia, assigner to hio Ferro-Alloys Corporation, Canton, Ghia, a corpora tion of Ohio Application May 27, 1957, Serial No. 651,710

l2 Claims. (Cl. )t3- 16) The invention relates to improvements in holders for electrodes in electric arc furnaces, and more particularly to a spring-operated clamp for holding an electrode and uid pressure mechanism for releasing the clamp.

ln such electrode holders as are now in general use, the pressure compensating mechanism for the electrode clamp tends to become very hot during operation, due to the proximity thereof to the extremely hot electrode. As spring means is ordinarily used in such mechanism, the eX- treme heat to which the spring is thus subjected causes rapid deterioration of the spring. Attempts have been made to cool such mechanism, but such devices as have been used have relatively complicated cooling arrangements.

Itis therefore an object of the present invention to provide a spring-operated electrode clamp in which the spring mechanism is located at a point remote from the hot electrode.

Another object is to provide such a device in which the spring mechanism is located remote from the clamping members and operatively connected thereto by levers.

A further object is to provide a device of this character in which the clamping members are forced against the electrode by a spring under compression, the spring being contained within and water cooled within an enclosure.

A still further object is to provide a device of this type in which the spring is contained within a watercooled enclosure together with a hydraulic cylinder which may be operated to overcome the spring pressure.

Another object of the invention is to provide such electrode clamping means in which there is a continuous circuit of water cooling the interior of the cylinder, the Water circuit being controlled so as to become a trapped system upon which high pressure can be applied to operate the cylinder.

A further 4object is to provide a clamping means of this character in which a compressible fluid may be provided in the cylinder instead of a compression spring for forcing the clamping members against the electrode.

A still further object is to provide an electrode clamp of the type referred to in which the cylinder is operatively connected to the clamping members by a pair of watercooled levers which may be either collaterally pivoted or decussately pivoted, as may be adapted to variations in design of the spring-hydraulic cylinder.

It is also an object of the invention to provide such clamping means in which a duplex cylinder or fluid pressure accumulator is provided for applying high pressure to the water trapped in the circuit supplying the springloaded cylinder.

Another object is to provide electrode clamping means of the character referred to having a spring-hydraulic cylinder with a piston therein and means for continuously circulating cooling water within the cylinder on each side of the piston.

A further object is to provide electrode clamping means of this type in which a compressible fluid is located Within the cylinder on one side of the piston and adapted to be compressed by uid pressure on the -other side of the piston, and in which cooling Water is circulated through a coil within the compressible fluid.

And finally, it is an object of the present invention to provide such a device in which cooling water may be continuously circulated within the cylinder on each side of the piston, and high pressure may be applied to the cooling water on one side of the piston for operating the cylinder to release the clamping members.

The above and other objects, apparent from the drawings and following description, may be attained, the above described difficulties overcome and the advantages and results obtained, by the apparatus, construction, arrangement and combinations, subcombinations and parts which comprise the present invention, a preferred embodiment of which, illustrative of the best mode in which applicant has contemplated applying the principle, being set forth in detail in the following description and illustrated in the accompanying drawings.

in general terms, the invention may be brielly described as comprising an automatic electrode clamping device comprising clamping members in the form of a pair of substantially semi-circular clamping bands hingedly connected together at one end, and encircling an electrode. These clamping bands may be water cooled as in usual practice.

The clamping bands are forced against the electrode by means of an operating cylinder having a piston therein, and operatively connected to the clamping bands through a pair of pivoted, water-cooled levers connected at opposite ends to the cylinder and to the free ends of the clamping bands. These levers may be either collaterally pivoted or decussately pivoted, depending upon the design of the cylinder.

Pressure is applied to one side of the piston to normally force the clamping bands into clamping engagement with the electrode. This pressure may be produced by a compression spring located within the cylinder, upon one side of the piston, or by a compressible fluid located in the cylinder on that side of the piston.

The cylinder is cooled by means of a continuous circuit of cooling water on each side of the piston. The circuit of cooling water, on the opposite side of the piston to the pressure means, is so controlled as to become a trapped system so as to apply pressure upon that side of the piston to overcome the spring or compressible fluid in order to release the clamping bands.

A duplex cylinder or fluid pressure accumulator is provided for applying high pressure to the water trapped in the circuit supplying the spring-loaded cylinder.

Having thus brielly described the invention, reference is now made to the accompanying drawings showing preferred embodiments of the invention, in which:

Fig. l is a front elevation of an embodiment of the improved electrode clamping device, showing a springloaded cylinder operatively connected7 through collaterally pivoted water-cooled levers, to the electrode clamping bands, parts being broken in section for the purpose of illustration;

Fig. 2 is a side elevation of the electrode clamping device shown in Fig. l;

Fig. 3 is a horizontal sectional view taken on the line 3 3, Fig. l., showing an electrode clamped within the clamping bands;

Fig. 4 is a fragmentary side elevation showing the electrode clamped within the clamping bands;

Fig. 5 is a longitudinal sectional view through the duplex cylinder or iluid pressure accumulator for applying high pressure to the water trapped in the circuit supplying the spring-loaded cylinder;

Fig. 6 is a diagrammatic view showing the valves and piping connecting the spring-loaded cylinder, the `circuit supplying water thereto, the duplex cylinder and the high pressure fluid system;

Fig. 7 is a longitudinal sectional View through a moditied form of cylinder, in which a compressible fluid is substituted for the spring pressure on one side of the piston; and

Fig. 8 is a 'front elevation with parts broken away of a modified embodiment of the invention in which a modified spring-loaded .cylinder is shown operatively connected to the clamping bands through a pair of decussately pivoted levers.

Referring now more particularly to the embodiment of the invention illustrated in Figs. 1 to 6, a portion of an electrode is indicated at 1t). The electrode clamping members comprise a pair of substantially semi-circular clamping 'bands 11, hingedly connected together at one end, `as indicated at 12, and having conventional pads 13 on their inner :sides for contact with the electrode, as best shown in Fig. 3.

Each `of the clamping bands 11 is water cooled. For this purpose, passages 14 are provided through each clamping band and nipples 15 are provided thereon for the attachment of hose or the like for continuously circulating cooling water through the passages 14.

A socket 16 is formed in the free end ot each of the clamping bands 11 for receiving pressure means for forcing the two bands toward each other so `as to clamp the electrode therebetween.

As shown in Figs. 1 to 4, this pressure means includes a pair of levers, indicated generally at 17. These levers have ybosses 18 on their lower ends located in the sockets 16 of the clamping `bands `and adapted to be normally urged toward each other by means of a spring-loaded cylinder indicated generally at 19 and operatively connected to the upper ends of the levers i7.

Each of the levers 17 is adapted to be water cooled and for this purpose each lever comprises a spaced pair of hollow legs 20 communicating at their lower ends as at 20a whereby cooling water may be circulated entirely therethrough.

The levers 17 are lcollaterally pivoted by means of a hollow water-cooled bolt 21, one end ot' which is pivotally connected to one leg Ztl as at 22. The other end of the bolt 21 is located `between the spaced legs 20 of the other lever 17 and is located through a plate 23 bearing against or attached to the outer side of said other lever 17.

A 'nut 24, with rounded surface 25 bearing upon the plate 23, is threaded upon the end of the bolt 21, thus permit-ting pivotal movement of the two levers 17 relative to the water-cooled bolt 21.

Cooling water may be circulated through the hollow levers 17 and hollow lbolt 21 by means of a hose or the like attached to the inlet 26 in one hollow leg 2i) of one lever 17. f

An 'outlet nipple 27 communicates with the other hollow leg 2t) of this lever 17 and is connected to a hose or tubing 28 as by the iitting 29. The tubing 2S is connected, yby inlet fitting 30, to the hollow bolt 21, and an outlet litting 31 upon said hollow 1bolt is connected by a hose or tubing 32 to a iitting 33 attached to the inlet nipple 34 in one hollow leg 2t) of the other lever 17.

An outlet nipple 35 on the other hollow leg 20 of said last-named lever 17 is connected by tting 36 with a hose or tubing 37. Thus, water may be continuously circulated through both legs of each lever 17 and through the hollow holt 21.

The cylinder, indicated generally at 19, is provided with the heads 33 and 39 at opposite ends thereof. The head 33 has an ear 40 integrally formed thereon, or rigidly attached thereto, and pivotally connected to the upper end of the adjacent lever 17 `as by the pivot pin 41.

A piston 42 is `slidably mounted within the cylinder 19 and the piston rod 43 thereof is located through the stuing box 44 in the head 39 of the cylinder and provided at 'its outer end with an eye 45 pivotally connected to the other lever 17, as by the pivot pin 46.

The piston 42 is normally urged toward the right, as viewed in Fig. l, by means of a coil spring 47 located within the cylinder 19 under compression between the head 38 and the piston 42. A rod 48 may be mounted upon the piston for Contact with the head 38 of the cylinder to act as a stop for the piston in order to limit the` compression of the spring 47 The cylinder 19 is adapted to be continuously water cooled. For this purpose, an inlet 49 is provided in the head 38 and connected by titting 50 with the tube 37. The inlet communicates through a longitudinal passage 51 with the inlet pipe 52 extending longitudinally within the cylinder and located within the coil spring 47.

A longitudinal outlet passage 53 provides communication between the interior of the cylinder and the outlet port 54 to which an outlet pipe or hose 55 may be connected. For the purpose of continuously water cooling the other end of the cylinder 19, upon the opposite side of the piston 42, an inlet passage 56 is formed in the head 39 and communicates with the water supply pipe 57.

An outlet passage 58, in the head 39, communicates with the outlet pipe 59. Thus, cooling water may be continuously circulated, by separate circuits, through each end of the cylinder, on opposite sides of the piston.

Although the cooling water continuously circulates through the inlet 49 and outlet 55, continuously cooling the coil spring 47 and adjacent portion of the cylinder 19, means is provided for controlling the circulation of water through the other end of the cylinder, that is through the inlet pipe 57 and outlet pipe 59.

This means is shown in Fig. 6 as a valve indicated generally at 60. This valve is shown of the rotatable plug type, the rotatable plug 61 having a port 62 therethrough which, as shown in full lines in Fig. 6, normally connects the pipe 59 with the outlet pipe 63, so that water from the supply pipe 57 continuously flows freely through this end of the cylinder, with the valve in this open position.

When the valve plug 61 is turned to the closed position, an'indicated by broken lines in Fig. 6, it will be seen that this circuit will become a trapped system, since the check valve 64 will prevent the Water from passing backward in the supply pipe 57.

Thus, pressure in this end of the cylinder Will tend to move the piston against the pressure of the spring 47, operating the levers 17 to release the clamping bands 11 Iand permit the electrode 1i) to slide downward in the furnace.

For Ithe purpose of applying high pressure to the water trapped in this circuit, a duplex cylinder or uid pressure accumulator indicated `generally at 65 in Figs. 5 and 6, is provided in association with a second water supply lino 66 and an oil supply line 67.

A duplex piston, comprising a spaced pair of pistons l68 and 68a joined by a rod 68h, is located within the Cylinder 65. Heads 69 and 70 are located in opposite ends of the cylinder 65. An outlet 65a in the center of the duplex cylinder 65 provides for the discharge to the atmosphere of any leakage of water or oil which may pass around the pistons 68 and 68a respectively to the center of the cylinder. The head 69 has an inlet passage 71 therein connected by pipe 72 with the por-t 81 of the valve 73 in lthe oil line 67.

The head 7() has an inlet passage 74, communicating with the water supply pipe 66, and an outlet passage 75 communicating with the pipe 76 leading to the -port 77 in 'the valve 7S.

Normally the rotary plug 79 of the oil valve 73 is located in the full line position shown in Fig. 6, so that the passage 8i) therein forms communication between the port 81 communicating with the pipe 72 and 'the port 82 communicating with 'the oil return pipe 83.

The inlet port S4 of this valve is thus closed, so .that oil pressure from the oil sup-ply pipe 67 cannot pass through the valve 73 to the duplex cylinder 65.

rThe rotary valve plug 85 of the valve 78 is normally in the full line ,position shown in Fig. 6, so that the passage 86 therethrough does not provide communication between the water inlet pipe '76 and the water outlet pipe 87.

The valves 60, 78 and 75 z re all adapted to be operated simultaneously, by means or' the levers 88 connected to the valve plugs, and the link 09, so that the three valves may be moved in unison from the full line position to the broken line position shown in Fig. 6.

When the valves are moved to this broken line position, the valve plug 61 of the valve 60 will be closed, preventing discharge of water from the cylinder 19 through the pipe 59. At the same time the valve '78 will be opened, permitting iiow or" water from the supply pipe 66 through the inlet 74 and outlet 75 of the duplex cylinder 65, then through the pipe 76, valve 7S and pipes 87 and 57 to the spring-loaded cylinder 19.

At the same time, oil under pressure will be admitted from oil supply line 67 through the valve 73 and inlet 71 to the other end of the duplex cylinder 65, against the piston 68a, forcing the same to the right, as Viewed in the drawings, and as the piston 68 is thereby moved to the right, high pressure will be built up in the water line 76, S7 and 57 to the spring-loaded cylinder 19, thus immediately overcoming the presssure of the spring 47 therein and operating the levers 17 to release the clamping bands 11.

The above-described device may be modiiied by substituting for the spring-loaded cylinder 19 a cylinder in which the piston is pressure loaded with a compressible liuid instead of a spring. Such a cylinder is indicated generally at 19a in Fig. 7. The piston 42a is slidably located Within the cylinder and is provided with a rod 43a having an eye 45a at its end for pivotal connection to one of the levers in the manner above described and as illustrated in Fig. l.

The piston rod 65a is slidable through a stuing boX 44a in the head 39a of the cylinder. An inlet passage 56a in the head 39a communicates with the water supply pipe 57 and an outlet passage 58a in the head 39a communicates with the water outlet pipe 59.

Thus water may be admitted from the pipe 57 to the interior of the cylinder 19a on the right side of the piston 42a as viewed in Fig. 7, and discharged through the outlet passage 55a to the pipe 59 in the same manner as illustrated and described with reference to Figs. l and 6.

The pipe 59 would of course lead to the valve 60 as shown in Fig. 6 so that the circuit of cooling water passing through this side of the cylinder may be trapped in order to move the piston to the left.

For the purpose of limiting movement of the piston toward the left, as viewed in Fig. 7, a stop ring 90 is Welded or otherwise secured within the cylinder 19a at the desired point.

Instead of providing a compression spring within the cylinder 19a to normally urge the piston 42a to the right, in the manner illustrated and described with reference to Fig. 1, the cylinder is lled with a compressible fluid between the piston 42a and the head 38a for normally urging the piston 42a to the right, as shown in Fig. 7.

An integral rod 40a is attached to the head 38a of the cylinder and provided with an eye for pivotal attachment to the other lever in the manner above described and as illustrated in Fig. 1.

For the purpose of water cooling the interior of the cylinder 19a, on the left side of the piston 42a, as viewed in Fig. 7, a water cooling coil 91 is shown connected at one end to the cooling water inlet 49a in the head 38a and at the other end to the cooling water discharge port 54a in the head 38a of the cylinder.

With this construction the clamping device may be operated in the manner above described with reference to Fig. l. Normally, the compressible fluid within the cylinder upon the left side of the piston will urge the piston toward the right in order to operate the levers to 6 hold the clamping device in clamping position around the electrode.

When the valve 60 in Fig. 6 is closed to trap the cooling water in the pipe 59, the water pressure on the right side of the piston 42a will become suicient to compress the compressible fluid on the left side of the piston so as to move the piston toward the left, operating the levers to release the clamping bands and permit the electrode to slide downward.

In Fig. 8 is shown a modification of the invention in which a spring-loaded cylinder is operatively connected to a pair of decussately pivoted levers which operate the clam-ping bands around the electrode.

In this embodiment of the invention the cylinder is indicated generally at 92 and is provided at one end with a head 93 having a rod 94 formed integrally thereon, or rigidly attached thereto, and provided with an eye 95 for pivotal connection by a pivot pin 96 to the upper end of one of the decussately pivoted levers 97.

An inlet passage 98 is formed in the head 9.3 and come municates with the water supply pipe 57 such as shown diagrammatically in Fig. 6. An outlet passage 99 in the head 93 communicates with the water discharge pipe 59 which is the same as shown diagrammatically in Fig. 6.

Thus cooling water may be continuously passed through the left end of the cylinder 92, on the left side of the piston 100 therein, from the water supply pipe 57 to the water discharge pipe 59 and the same may be controlled by the valve 60, as shovm in Fig. 6 andv above described, so as to become a trapped system upon which high pressure can be applied to move the piston 100 toward the right, against the pressure of the compression spring 101 which is located on the right side of the piston between the same and the head 102 of the cylinder.

The piston rod 103 is located through a suitable stuifing box 104 in the head 102 and provided at its end with an eye 105 for pivotal connection, as by the pin 106, with the upper end of the other decussately pivoted lever 97.

Cooling water may be continuously circulated through the cylinder on the right side of the piston to cool the spring 101 and adjacent parts of the cylinder and piston. For this purpose a cooling water inlet 107 and discharge outlet 108 are formed in the head 102.

Each of the levers 97 may be hollow and may be water cooled in any conventional manner. The intermediate portions of the levers 97 are crossed and pivoted, as by the pivto pin 109. Bosses 18a are formed upon the lower ends of the levers 97 for engagement in the sockets 16 of the clamping bands 11 which may be of the same construction as shown in Figs. l to 4, and the same reference numerals are applied thereto.

With this construction, as shown in Fig. 8, the compression spring 101 normally urges the piston 100 to the left, as viewed in the drawings, pulling the upper ends of the decussately pivoted levers 97 toward each other and correspondingly moving the lower ends of the levers toward each other, so that the bosses 18o thereon engaging the sockets 16 of the clamping bands 11 hold the clamping bands tightly against the electrode.

Cooling water is continuously passed through both sides of the cylinder, and when it is desired to release the clamping bands to permit the electrode to slide downward in the furnace, the valve 60 in Fig. 6 is operated to trap the water in the pipe 59 so as to cause the Water pressure in the left side of the cylinder to urge the piston 100 toward the right, against the pressure of the spring 101, moving the upper ends of the levers 97 apart and correspondingly moving the lower ends thereof away from each other, so as to release the clamping bands 1l.

It should be understood that in the form of the invention shown in Fig. 8, with the decussately pivoted levers, a compressible fluid-operated cylinder may be substituted for the spring-loaded cylinder 92.

From the above it will be obvious that an automatic electrode clamping device is provided in which the clamping bands are operated by levers remotely controlled by an operating cylinder which may be either spring loaded or compressible fluid-loaded.

The spring or compressible lluid is contained in a water-cooled enclosure together with the hydraulic cylinder. There is a continuous circuit of Water cooling the interior of the cylinder on each side of the piston, and the water circuit on the side of the piston opposite to the spring .or compressible fluid is so controlled as to become a trapped system upon which high pressure can be applied to operate the piston against the pressure of the spring, or compressible uid, to release the clamping bands.

It Will also be seen that the device includes a novel structure in the form ofthe duplex cylinder or fluidpressure accumulator for the purpose of applying high pressure to the Water trapped in the circuit supplying the spring-loaded or compressible fluid-loaded cylinder.

in the foregoing description, certain terms have been used for brevity, clearness and understanding, but no unnecessary limitations are to be implied therefrom beyond the requirements of the prior art, because such words are used for descriptive purposes herein and are intended to be broadly construed.

Moreover, the embodiments of the yimproved construction illustrated and described herein are by way of example, and the scope of the present invention .is not limited to the exact details of construction.

Having now described the invention Lor discovery, the construction, the operation, and use of preferred'embodiments thereof, and the advantageous new and :useful results obtained thereby; the new and useful construction, and reasonable kmechanical equivalents thereof obvious to those skilled in the art, are set forth in the appended claims.

I claim:

l. An electrode clamping device comprising clamping bands, a hydraulic cylinder having a piston therein :for operating the clamping bands, pressure means in the cylinder on one side of the piston for forcing the clamping bands into contact with the electrode, means providing a continuous circuit of cooling Water within the cylinder on the other side of the piston, and means for trapping the cooling Water in said circuit for applying presure against said other side of the piston to overcome said pressure means and release the clamping bands.

2. An electrode clamping device comprising clamping bands, a hydraulic cylinder having a piston therein for operating the clamping bands, pressure means in the cylinder on one side of the piston for forcing the clamping bands into contact with the electrode, means providing a continuous circuit of cooling vater Within the cylinder on the other side of the piston, means for trapping the cooling water in said circuit, and means for applying high pressure to the water trapped in said circuit and against said other side of the piston to overcome said pressure means and release the clamping bands.

3. An electrode clamping device comprising clamping bands, a hydraulic cylinder having a piston therein for operating the clamping bands, spring pressure means in the cylinder on one side of the piston for forcing the clamping bands into contact with the electrode, means providing a continuous circuit of cooling water Within the cylinder on the other side of the piston, and means for trapping the cooling Water in said circuit for applying pressure against said other side of the piston to overcome said spring pressure means and release the clamping bands.

4. An electrode clamping device comprising clamping bands, a hydraulic cylinder having a piston therein, pivoted levers operatively connecting the hydraulic cylinder and piston to the clamping bands, spring means in the cylinder on one side of the piston for forcing the clamping bands into contact with the electrode, means for applying hydraulic pressure against the other side of the piston to overcome said spring means and release the clamping bands, and means for continuously circulating cooling Water within said cylinder and around said spring means.

5. An electrode clamping device comprising clamping bands, a hydraulic cylinder having a piston therein, pivoted water-cooled levers operatively connecting the hydraulic cylinder and piston to the clamping bands, spring means in the cylinder on one side of the piston for forcing the clamping bands into contact With the electrode, rmeans for applying hydraulic pressure against the other side of the piston to overcome said spring means and release the clamping bands, and means for continuously circulating cooling Water Within said cylinder and around said spring means.

6. An electrode clamping device comprising clamping bands, a hydraulic cylinder having a piston therein, collaterally pivoted levers operatively connecting the hydraulic cylinder and piston to the clamping bands, spring means in the cylinder on one side of the piston for forcing the clamping bands into-contact with the electrode, means for applying hydraulic pressure against the other side of the piston to overcome said spring means and release the clamping bands, and means for `continuously circulating cooling Water within said cylinder and around Said'spring means.

7. An electrode clamping device comprising clamping bands, a hydraulic cylinder having a piston therein, decussately pivoted levers operatively connecting the hydraulic cylinder and piston to the clamping bands, spring means in the cylinder on one side of the piston for forcing the clamping bands into contact with the electrode, means for applying hydraulic pressure against the other side of the piston to overcome said spring means and release the clamping bands, and means for continuously circulating cooling Water Within said cylinder and around said spring means.

8. A11 electrode clamping device comprising clamping bands, a hydraulic cylinder having a piston therein for operating the clamping bands, spring means in the cylinder on one side of the piston for forcing the clamping bands into contact with the electrode, means providing continuous circuits of cooling water in the cylinder on each side of the piston and around said spring means, and means for trapping the cooling Water in the circuit onthe opposite side of the piston from said spring means for Aapplying pressure against said opposite side of the piston to overcome said spring means and release the clamping bands.

9. An electrode clamping device comprising clamping bands, a hydraulic cylinder having a piston therein for operating the clamping bands, spring means inthe cylinder on one side of the piston for forcing the clamping bands into contact With the electrode, means providing continuous circuits of cooling water in the cylinder on each side of the piston and around said spring means, means lfor trapping the cooling Water in said circuit on the opposite side of the piston from said spring means, and means for applying high pressure to the Water trapped in said circuit and against said opposite side of the piston to overcome said spring means and release the clamping bands.

10. An electrode clamping device comprising electrode clamping members, a cylinder for operating the clamping members, a spring-loaded piston in the cylinder for urging the clamping members into clamped position, means for continuously water cooling the cylinder and the spring therein, and means for applying hydraulic pressure to the piston to overcome the spring and release the clamping members.

11. An electrode clamping device comprising electrode clamping members, a cylinder for operating the clamping members, a spring-loaded piston in the cylinder for urgingthe clamping members into clamped position,

water supply and discharge pipes for circulating cooling water through the cylinder on the side of the piston opposite to the spring, a normally open valve in the discharge pipe, a duplex cylinder having a piston therein, a Water line located through the duplex cylinder on one side of the piston therein and communicating with said water-supply pipe, a normally closed valve in said water line, an oil line connected to the duplex cylinder on the other side of the piston therein, a normally closed valve in said oil line, and means for a simultaneously closing said normally open valve and opening said normally closed valve for trapping the cooling water in said water supply and discharge pipes and admitting oil pressure to said duplex cylinder to apply water under high pressure from said water line to said trapped water to overcome the spring pressure in said cylinder and release the clamping members.

12. An electrode clamping device comprising electrode clamping mem-bers, a cylinder for operating the clamping members, a spring-loaded piston in the cylinder for urging the clamping members into clamped position, water supply and discharge pipes for circulating cooling water through the cylinder on the side of the piston opposite to the spring, a normally inoperative duplex cylinder, and means for simultaneously trapping the cooling water in said supply and discharge pipes and operating the duplex cylinder to apply high pressure to the trapped water to overcome the spring pressure and release the clamping members.

No references cited.

Claims (1)

1. AN ELECTRODE CLAMPING DEVICE COMPRISING CLAMPING BANDS, A HYDRAULIC CYLINDER HAVING A PISTON THEREIN FOR OPERATING THE CLAMPING BANDS, PRESSURE MEANS IN THE CYLINDER ON ONE SIDE OF THE PISTON FOR FORCING THE CLAMPING BANDS INTO CONTACT WITH THE ELECTRODE, MEANS PROVIDING A CONTINUOUS CIRCUIT OF COOLING WATER WITHIN THE CYLINDER

Images