Lateral hoist for electrode columns of electric arc melting furnaces
A device for moving electrode columns of electric arc melting furnaces, characterised by consisting essentially of a lever the central fulcrum of which is connected to the hook of the overhead crane by an articulated ring, on one side a coupling mechanism being inserted into a tube and intended for coupling to the electrode column, while on the other side a counterweight of predetermined weight balances the device during its movement.
1. A device for moving electrode columns of electric arc melting furnaces, comprising:
a tubular coupling device configured to surround and secure one of the electrode columns having an elongated cam able to be locked against said one of said electrode columns when it is required to raise said device for moving electrode columns;
a lever having a rotatable, fork-shaped frame with two sides and a single portion, whereby the two sides of the fork-shaped frame are pivotable with respect to the tubular coupling device; said lever presenting a fulcrum fixed to a hook of a lifting device; said tubular coupling device being lateral to said fulcrum; and
a counterweight of predetermined weight is fixed to the single portion of the fork-shaped frame of the lever; said fulcrum is positioned in a asymmetric position with respect to a length of the lever, the counterweight of predetermined weight is raised by said lifting device of an amount required to balance the weight of said one of the electrode columns to maintain said one of the electrode columns vertical during movement of the lifting device,
wherein the elongated cam is operable in a closed position such that the elongated cam grips a surface of said one of the electrode columns to secure said one of the electrode columns to the tubular coupling device when the hook is raised and the elongated cam is automatically releasable from said closed position to allow movement of the tubular coupling device when the hook is lowered.
2. A device as claimed in claim 1 , characterised in that said counterweight of predetermined weight is adaptable to the maximum weight of the electrode column to be raised.
3. A device as claimed in claim 1 , characterised in that said counterweight of predetermined weight is fixed to said lever on the opposite side to that to which said tubular coupling device is fixed.
4. A device as claimed in claim 1 , further comprising at least one bolt for fixing said counterweight of predetermined weight to the single portion of the fork-shaped frame.
5. A device as claimed in claim 4 , characterised in that said fulcrum comprises a pin positioned in proximity to the joint between said two sides of the fork-shaped frame and said single portion of the fork-shaped frame.
6. A device for moving electrode columns of electric arc melting furnaces, comprising:
a tubular coupling device configured to surround one of the electrode columns having an elongated cam able to be locked against said one of the electrode columns when it is required to raise said device for moving electrode columns;
a lever including a rotatable, fork-shaped frame having with two sides and a single portion; said lever presenting a fulcrum fixed to a hook of a lifting device; and
a counterweight of predetermined weight fixed directly to the single portion of the fork-shaped frame of the lever for balancing the tubular coupling device during movement,
wherein the elongated cam is operable in a closed position such that the elongated cam grips a surface of said one of the electrode columns to secure said one of the electrode columns to the tubular coupling device when the hook is raised and the elongated cam is automatically releasable from said closed position to allow movement of the tubular coupling device when the hook is lowered,
whereby the counterweight of predetermined weight is raised by the lifting device an amount required to balance said one of the electric columns and maintain said one of the electric columns vertical during movement of the lifting device.
7. A device for moving electrode columns of electric arc melting furnaces, comprising:
a tubular coupling device on one of said electrode columns having an aperture for allowing access to said one of the electrode columns, a plated and an elongated cam supported by the plate, said elongated cam having a first end pivoted on a pin and an opposite end resting on said one of said electrode columns; and
a lever associated with a counterweight of predetermined weight rotatably fixed to the tubular coupling device, said lever presenting a fulcrum fixed to a hook of a lifting device, said tubular coupling device being lateral to said fulcrum, wherein the elongated cam is operable in a closed position such that the elongated cam grips a surface of said one of the electrode columns to secure said one of the electrode columns to the tubular coupling device when the hook is raised and the elongated cam is automatically releasable from said closed position to allow movement of the tubular coupling device when the hook is lowered,
whereby the counterweight of predetermined weight is laterally movable from a first position to a second position to balance the weight of the tubular coupling device and said one of the electrode columns and maintain said one of the electrode columns vertical during movement.
8. A device as claimed in claim 7 , wherein the counterweight of predetermined weight is substantially parallel to one of the electrode columns in the first position.
9. A device as claimed in claim 7 , wherein the counterweight of predetermined weight is not substantially parallel to one of the electrode columns in the second position.
10. A device as claimed in claim 7 , wherein the elongated cam is horizontally positionable relative to said one of said electrode columns by a pair of adjustable bolts.