FORM 2
THE PATENT ACT 1970
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)
1. TITLE OF THE INVENTION:
"Upper Electrode Holder for Electric Arc Furnaces"
2. APPLICANT
(a) NAME: Ghalsasi Smelting Pvt. Ltd.
(b) NATIONALITY: Indian Company
(c) ADDRESS: J-21,MIDC,Bhosari, Pune-411026,
Maharashtra, India
3. PRREAMBLE TO THE DESCRIPTION
COMPLETE
The following specification particularly describes the invention and the manner in which it is to be performed.

Upper Electrode Holder for Electric Arc Furnaces
Field of the invention
The present invention relates to electric arc furnaces, and more particularly, to an upper electrode holder for electric arc furnaces, primarily for submerged arc operation.
Background of the invention
Electro-thermal processes are carried out by the operation of electric arc furnaces in which electrical energy is utilized as the necessary source of heat for the melting and reduction of ores or melting of metals. In the electric furnaces, an upper electrode holder also known as an electrode slipping device is used to slip the electrode which is consumed inside the electric arc furnace shell during operation thereof. Generally, the electrode slipping device performs two operations in one slipping cycle. In a first operation, a first set of hydraulic cylinders use hydraulic pressure to de-clamp the electrode. In a second operation, a second set of hydraulic cylinders slips the electrode to the desired distance. Currently, the electric arc furnaces use two differently designed hydraulic cylinders to perform two operations respectively.
As the conventional electric arc furnaces use two set of the hydraulic cylinders for the upper electrode holder, manufactures and customers of the electric arc furnaces have to maintain different inventory for the two hydraulic cylinders. Further, these two hydraulic cylinders of different type are not modular or inter-changeable, which cause difficulty in repairs or replacement thereof.
Accordingly, there exists a need to provide an upper electrode holder/electrode slipping device for electric arc furnaces that overcomes the drawbacks of the prior art.

Objects of the invention
An object of the invention is to utilise the same hydraulic cylinder to be used for both operations of de-clamping each ring as well as lifting and lowering of an upper ring for slipping operations.
Another object of the present invention is to reduce inventory of hydraulic cylinders required for manufacturing an upper electrode holder for electric arc furnaces.
Yet another object of the present invention is to provide a modular or inter-changeable hydraulic cylinder for the upper electrode holder of the electric arc furnaces.
Summary of the invention
Accordingly, the present invention provides an upper electrode holder for electric arc furnaces. The upper electrode holder comprises of a plurality of upper segments, a plurality of lower segments, a plurality of hydraulic cylinders, a plurality of spring mechanisms, a plurality of lever mechanisms, a first set of clamps and a second set of clamps.
The plurality of upper segments is removably secured together to form an upper ring and the plurality of lower segments is removably secured together to form a lower ring. The upper ring and the lower ring form a cavity that is capable of holding an electrode therein. The plurality of hydraulic cylinders is mounted on the plurality of upper segments and the plurality of lower segments. The plurality of spring mechanisms is capable of flexibly forcing the first set of clamps and the second set of clamps against the electrode. The plurality of hydraulic cylinders connects segments and the clamps via the plurality of lever mechanisms. The clamps mounted in the

segments removably engage the electrode. The first set of clamps is mounted on the plurality of upper segments and is capable of de-clamping by the plurality of hydraulic cylinders. The second set of clamps is mounted on the plurality of lower segments and capable of de-clamping by the plurality of hydraulic cylinders. The plurality of hydraulic cylinders is inter-changeable. The first set of clamps, the second set of clamps and the plurality of hydraulic cylinders perform dual operation of de-clamping and slipping of the electrode held between the plurality of upper segments and the plurality of lower segments.
The hydraulic pressure of the plurality of hydraulic cylinders causes de-clamping of the first set of clamps, upward movement of the plurality of upper segments, positioning back the first set of lever mechanisms, de-clamping of the second set of clamps, downward movement of the upper segment along with the electrode and positioning back the second set of lever mechanisms thereby causing slipping of the electrode at a desired set point. Re-clamping of the clamps is by means of the plurality of spring mechanisms as the lever mechanisms are returned to their initial positions.
Brief description of the drawings
Figure 1 shows a perspective view of an upper electrode holder for an electric arc furnace, in accordance with the present invention;
Figure 2 is another perspective view of the upper electrode holder showing a cavity;
Figure 3 shows a cross sectional view of the upper electrode holder of figure 2; and
Figure 4 shows a schematic drawing of the upper electrode holder for the electric arc furnace, in accordance with the present invention.

Detailed description of the invention
The foregoing objects of the present invention are accomplished and the problems and shortcomings associated with the prior art, techniques and approaches are overcome by the present invention as described below in the preferred embodiments.
The present invention provides an upper electrode holder/electrode slipping device for electric arc furnaces. With the upper electrode holder of the present invention a plurality of hydraulic cylinders perform dual operation of de-clamping each ring as well as lifting and lowering of an upper ring. The present invention reduces inventory of the hydraulic cylinder while manufacturing the upper electrode holder for electric arc furnaces. The upper electrode holder for electric arc furnaces of the present invention provides a modular or inter-changeable hydraulic cylinder for the electric arc furnaces.
This present invention is illustrated with reference to the accompanying drawings, throughout which reference numbers indicate corresponding parts in the various figures. These reference numbers are shown in bracket in the following description.
Referring to figures 1-4, there is shown an upper electrode holder/electrode slipping device (100) (hereinafter 'the holder (100)') for electric arc furnaces, in accordance with the present invention. The holder (100) is cylindrical. In an embodiment, the holder (100) is primarily used for submerged arc operation.
The holder (100) comprises a plurality of upper segments (10). a plurality of lower segments (20), a first set of clamps (30), a second set of clamps (40),a plurality of lever mechanisms (50a, 50b), a plurality of spring mechanisms (60), a plurality of hydraulic cylinders (70a, 70b) and a plurality of mechanical hard stops (80a, 80b).

. The plurality of upper segments (10) are removably secured together to form an upper ring (not numbered). The plurality of lower segments (20) are removably secured together to form a lower ring (not numbered).The upper ring and the lower ring form a cavity (15) for holding an electrode (120) therein. The plurality of spring mechanisms (60) is connected to the plurality of upper segments (10) and the plurality of lower segments (20). The plurality of spring mechanisms (60) flexibly forces the clamps (30, 40) against the electrode (120). The plurality of hydraulic cylinders (70a. 70b) connects between the segments (10, 20) and the clamps (30, 40) via the lever mechanisms (50a, 50b) on the plurality of upper segments (10) and the plurality of lower segments (20).
The clamps (30, 40)removably engage the electrode (120).In an embodiment, the plurality of hydraulic cylinders (70a, 70b) is a double acting hydraulic cylinder that performs dual operation of de-clamping and slipping the electrode (120).The hydraulic cylinders (70a) de-clamp the first set of clamps (30). The hydraulic cylinders (70b) de-clamp the second set of clamps (40). The cylinders (70a, 70b) are used in conjunction to simultaneously perform de-clamping of either the first set of clamps (30) or the second set of clamps (40) and the movement of the plurality of upper segments (10) during a slipping operation.
The plurality of mechanical hard stops (80a, 80b) is used to limit the opening and closing of the first set of clamps (30) and the second set of clamps (40).
In an embodiment, all the operations of the components of the holder (100) are interlocked through a control device (not shown) for example, Programmable Logic Controller (hereinafter "PLC") thereby making the functioning of the holder (100) fail safe. The PLC is positioned in a control room to remotely control the operation of the holder (100).

Referring again to figures 1-4, in operation, firstly, the plurality of hydraulic cylinders (70a) positioned on the plurality of lower segments (20) is actuated to de-clamp the first set of clamps (30). The plurality of mechanical hard stops (80a) controls the de-clamp operation of the first set of clamps (30). Once the de-clamp operation is complete, the hydraulic pressure is sensed in the control room by the PLC and at a desired set point the next step is triggered.
In next step, all the plurality of hydraulic cylinders (70a, 70b)are activated thereby lifting the plurality of upper segments (10) to up position. At the same time the second set of clamps (40) remains closed by means of the plurality of spring mechanisms (60). The lever mechanism (50b) is locked in position on the mechanical hard stop (80b) resulting in locking of the plurality of hydraulic cylinders (70a, 70b) to their position. Once the plurality of upper segments (10) is moved up to the desired position, the next step is triggered by either hydraulic pressure sensor (not shown) and/or an electrical position sensor (not shown) signal to the PLC.
In next step, the plurality of hydraulic cylinders (70a) positioned on the plurality of lower segments (20) are discharged and the first set of clamps (30) are clamped back. Once the clamping operation of the first set of clamps (30) is complete, the hydraulic pressure is sensed in the control room by the PLC and at the desired set point the next step is triggered.
In next step, the plurality of hydraulic cylinders (70b) positioned on the plurality of upper segments (10) are actuated causing de-clamping and opening of the second set of clamps (40). After the de-clamp operation of the second set of clamps (40)is complete, the hydraulic pressure is sensed in the control room by the PLC and at the desired set point the next step is triggered.
In next step, all the plurality of cylinders (70a, 70b) are activated and the plurality of

upper segments (10) moves down along with the electrode (120) causing the slipping action of the electrode (120).Once the operation of moving the plurality of upper segments (10) along with the electrode (120) downwards to the bottom position, the next step is triggered by either hydraulic pressure sensor (not shown) and/or an electrical position sensor (not shown) signal to the PLC.
In next step, all the plurality of cylinders (70b) positioned on the plurality of upper segments (10) are discharged and the second set of clamps (40) is clamped back. After the clamping operation of the second set of clamps (40) is complete, the hydraulic pressure is sensed in the control room by the PLC and at the desired set point the next step is triggered.
In an embodiment, hydraulic pressure in the plurality of hydraulic cylinders (70b) keeps the second set of clamps (40) open and subsequently slips the electrode (120) held by the first set of clamps (30) of the plurality of upper segments (10). Further, a throttle pressure in the plurality of hydraulic cylinders (70b) provides enough resistance to keep the second set of clamps (40) open while additional flow and pressure is applied to the plurality of hydraulic cylinders (70a) to slip the electrode (120) down to the desired set point.
A summary of the sequence of operations of the holder (100) to slip the electrode (120) down is as follows:
1. De-clamping of the first set of clamps (30),
2. Upward movement of the plurality of upper segments (10),
3. Re-clamping the first set of clamps (30),
4. De-clamp the second set of clamps (40),
5. Downward movement of the plurality of upper segments (10) along with the electrode (120) and
6. Re-clamping the second set of clamps (40)

Advantages of the invention
1. The upper electrode holder (100) utilises the same hydraulic cylinder to be used for both operations of de-clamping each ring as well as lifting and lowering of the upper ring for slipping operations.
2. The upper electrode holder (100) for the electric arc furnace requires maintaining low inventory of the hydraulic cylinders (70a, 70b).
The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omission and substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but such are intended to cover the application or implementation without departing from the spirit or scope of the present invention.

We Claim:
1. An upper electrode holder for an electric arc furnace, the upper
electrode holder comprising:
a plurality of upper segments, the plurality of upper segments removably secured together to form an upper ring;
a plurality of lower segments, the plurality of lower segments removably secured together to form a lower ring, the lower ring and the upper ring forming a cavity for holding an electrode therein;
a plurality of hydraulic cylinders mounted on the plurality of upper segments and the plurality of lower segments;
a plurality of lever mechanisms linking the plurality of hydraulic cylinders on the plurality of upper segments and the plurality of lower segments;
a first set of clamps mounted on the plurality of upper segments, the first set of clamps capable of being de-clamped by the plurality of hydraulic cylinders;
a second set of clamps mounted on the plurality of lower segments, the second set of clamps capable of being de-clamped by the plurality of hydraulic cylinders; and
a plurality of spring mechanisms being capable of flexibly forcing the first set of clamps and the second set of clamps against the electrode,
wherein, hydraulic pressure of the plurality of hydraulic cylinders causes de-clamping of the first set of clamps, upward movement of the upper segment, positioning back the first set of lever mechanisms, de-clamping of the second set of clamps, downward movement of the upper segment along with the electrode and positioning back the second set of lever mechanisms thereby causing slipping of the electrode at a desired set point.
2. The upper electrode holder as claimed in claim 1, wherein the plurality

of hydraulic cylinders are inter-changeable.
3. The upper electrode holder as claimed in claim 1, wherein the first set of clamps, the second set of clamps and the plurality of hydraulic cylinders perform dual operation of de-clamping and slipping of the electrode held between the plurality of upper segments and the plurality of lower segments.
4. The upper electrode holder as claimed in claim 1, wherein re-clamping of the first set of clamps and the second set of clamps is by means of the plurality of spring mechanisms as the lever mechanisms are returned to their initial positions..