Abstract: A drum cathode for the production of metal foil, the drum having a titanium top cylinder and a stainless steel base cylinder integrallly connected by welding (1) a niobium or vanadium ring to the top cylinder, (2) a copper ring to the niobium or vanadium ring, and (3) the base cylinder to the copper ring, so as to provide a high electric current carrying path between the top and base cylinder. The drum cathode eliminates the formation of "hot spots" during use, while permitting increased electric current flow and foil product rate.

Abstract: A drum cathode for the electrolytic production of metal foil having a current collection yoke of high current carrying capacity which electrically connects each end of the drum to a current collecting hub in the center of the drum. The current collecting hub is positioned on an electrically conducting sleeve over the drum's shaft for conducting the collected current to the exterior of the drum. This permits the electric current to flow through the top sheet of the drum symmetrically to enable the production of foil having a more uniform and symmetrical weight distribution across the width of the drums.

Abstract: A current limiting iron wire resistor having a transformable resistance for a current limiting circuit breaker. Each pole of the circuit breaker includes said resistor in parallel with a pair of auxiliary contacts for current limiting which are in series with a pair of main contacts to open the circuit. The main contacts are separable upon operation of a thermally and electromagnetically operable tripping mechanism, and the auxiliary current limiting contacts separate only on occurrence of a high amplitude fault current above a preselected threshold value. When that value of fault current is reached, the tripping mechanism and associated components which operate the auxiliary current limiting contacts serves to increase arc voltage almost instantaneously to that of the source, about which time the fault current is totally shunted into the current limiting resistor.

Abstract: A current limiting circuit breaker having for each pole, a pair of main contacts separable upon operation of a thermally and electromagnetically operable tripping device and a pair of auxiliary contacts for current limiting in series with the main contacts and in parallel with a transformable resistor having a positive temperature coefficient of resistance. The auxiliary contacts are separable when an electromagnet is energized by a fault current which simultaneously energizes a field magnet to produce a transverse magnetic field across the auxiliary contacts and the arc formed between them when separating. This simultaneous action of electromagnet and field magnet coacting for rapid contact separation and lengthening of the arc upon flow of a fault current serves to increase arc voltage almost instantaneously to that of the source, about which time the fault current is totally shunted into the resistor.

Abstract: An iron wire resistor connected in shunt with the current limiting contacts of a circuit breaker. The current limiting contacts are in series with the main contacts of the breaker, and are separated by extremely high fault currents before the main contacts can respond. Opening of the limiting contacts shunts the high fault current through the resistor. The resistor has a positive temperature coefficient of resistance and heats rapidly to sharply reduce the magnitude of the high fault current.To prevent the connection between the resistor and a low resistance copper conductor from being destroyed by the high fault current an intermediate resistance value terminal of copper clad stainless steel is employed between the resistor and the copper conductor.

Abstract: A current limiting circuit breaker having for each pole, a pair of main contacts separable upon operation of a thermally and electromagnetically operable tripping device and a pair of auxiliary contacts for current limiting in series with the main contacts and in parallel with a transformable resistor having a positive temperature coefficient of resistance. The auxiliary contacts are separable when an electromagnet is energized by a fault current which simultaneously energizes a field magnet to produce a transverse magnetic field across the auxiliary contacts and the arc formed between them when separating. This simultaneous action of electromagnet and field magnet coacting for rapid contact separation and lengthening of the arc upon flow of a fault current serves to increase arc voltage almost instantaneously to that of the source, about which time the fault current is totally shunted into the resistor.

Abstract: Current limiting circuit breaker having for each pole, a pair of main contacts separable upon operation of a thermally and electromagnetically operable tripping device and a pair of auxiliary contacts for current limiting in series with the main contacts and in parallel with a transformable resistor having a positive temperature coefficient of resistance. The auxiliary contacts are separable when an electromagnet is energized by a fault current which simultaneously energizes a field magnet to produce a transverse magnetic field across the auxiliary contacts and the arc formed between them when separating. This simultaneous action of electromagnet and field magnet coacting for rapid contact separation and lengthening of the arc upon flow of a fault current serves to increase arc voltage almost instantaneously to that of the source, about which time the fault current is totally shunted into the resistor.

Abstract: A current limiting circuit breaker having for each pole, a pair of main contacts separable upon operation of a thermally and electromagnetically operable tripping device and a pair of auxiliary contacts for current limiting in series with the main contacts and in parallel with a transformable resistor having a positive temperature coefficient of resistance. The auxiliary contacts are separable when an electromagnet is energized by a fault current which simultaneously energizes a field magnet to produce a transverse magnetic field across the auxiliary contacts and the arc formed between them when separating. This simultaneous action of electromagnet and field magnet coacting for rapid contact separation and lengthening of the arc upon flow of a fault current serves to increase arc voltage almost instantaneously to that of the source, about which time the fault current is totally shunted into the resistor.