Abstract: A multiple-stage hydraulic cylinder for shifting loads by exerting different forces over different distances, in which a hollow-piston cylinder is provided with a hollow piston rod. The hollow piston rod accommodates at least one additional long-stroke cylinder. The hollow piston rod, moreover, comprising a cylinder tube surrounding the long-stroke cylinder. Connections are provided for hydraulic fluid to move the cylinders. These connections are provided on the hollow piston rod and the long-stroke cylinder for admitting fluid to move the hollow-piston cylinder and the long-stroke cylinder.

Abstract: A tilting device for a direct current arc furnace and a process are disclosed for completely emptying the furnace while the furnace is operated with a continuous scrap supply through a lateral opening in the furnace vessel and removal bottoms. The scrap chute should remain in the opening of the furnace during the loading, melting, deslagging and tapping operations; it should be swiveled away only during the emptying of the furnace. The disclosed tilting device has a cam on the rolling cradle, so that the rolling mid-point remains at the zero position in a tilting range from .+-.5.degree. to .+-.15.degree., and when the furnace is completely emptied it moves to another position in a parallel direction to the bottom tapping opening. The position of the bottom tap opening changes only insignificantly in order to protect the parts of the bottom electrode located outside the vessel of the furnace from heat radiated by steel in the casting ladle.

Abstract: An electrical metallurgical furnace including a vessel and a bottom electrode positioned in the bottom of the vessel. At least one counter contact is provided connected to the bottom electrode. A support is anchored to the vessel connected to the insulation mounting unit. A tension frame is held by the insulation mounting unit. At least one current cable is provided for engagement with a side of the counter contact. A pivot element is provided for supporting the current cable. A biasing apparatus is provided for urging the pivotally supported current cable into contact with the counter contact.

Abstract: A DC arc or resistance melting furnace has a current supply line and a coolant supply line located in the furnace heart in the connection is constructed so that a point of separation is provided between an attachment assembly for the current and cooling lines and the vessel. The attachment assembly is formed at the terminal and fastened to the furnace vessel at a contact point. When changing the contact electrodes, it is a simple matter to undo the point of separation of the electrodes from the assembly without removing the coolant lines or the whole assembly may be removed.

Abstract: The contact connection of the contact electrode of an arc or resistance melting furnace with the supply terminal there is arranged at the base plate of the contact electrode a contact pipe which engages into a contact sleeve at the supply terminal includes a contact sleeve which is pressed against the contact pipe by means of a press-on desk.

Abstract: A direct current arc or resistance melting furnace includes a contact electrode produced as an exchangeable assembly outside the furnace and introduced into an opening provided in the bottom of the furnace tank. An annular gap between a refractory lining of the furnace tank and the contact electrode assembly is tamped.For exchanging the contact electrode assembly, it is detached from the lining with the aid of pressure elements (telescoping cylinders) arranged below the furnace tank and lifted upward far enough for the contact electrode to be pulled out of the furnace tank by the grip of a pulling device. Then a new contact electrode assembly is inserted.

Abstract: An electric furnace or electric arc or resistance melting furnaces comprises a housing with a refractory lining which defines a furnace hearth in the housing and with a plurality of electrodes extending through the refractory having one of their ends terminating in the hearth and the opposite ends extending out of the housing. A plate is arranged in spaced relationship to the housing on its exterior and is connected to the opposite ends of the electrodes. The plate is arranged to define a cooling space outside of the housing which surrounds the electrodes. A cooling fluid is circulated into the cooling space and over the electrodes.