A coaxial bus and bus system for electric furnaces which significantly reduces and minimizes heating and losses due to magnetic induction effects are characterized by a concentric tubular bus stem connected at one end to a transformer and branching at the other end to be connected to the furnace. The bus stem includes concentric tubular conductors which are connected at such one end to the transformer by respective diametrically opposed terminal lugs. At such other end, bus branches each including a conductive cross bar and a flexible feeder are respectively connected to the tubular conductors and form a yoke between which the furnace heating element or elements may be connected. The feeders are adjustably secured both pivotally to and longitudinally along their respective cross bars and each includes a plurality of stacked conductive leaves which are pressure welded together and to contact and reinforcing plates at their ends. Provision also is made for air or water cooling by means of coolant passages in the terminal lugs, bus stem and bus branches.
An air cooled kickless cable used in welding has each end of positive and negative stranded rope sets cold formed in a rectangular tube with such rope ends within the tube being formed into a continuous compacted strand with the ropes of the set arranged parallel to the long axis of the rectangle. The rectangle of the tube forms a major flat side which is press welded to one end of a contact plate. The press welding also welds the strands to each other, the strands to the tube, and, in addition the tube to the contact plate. The rope sets are assembled in a spider separator, and twisted with the contact plates fastened together with insulation therebetween. The cable is provided with a perforated cover, end tubes and heat shrink end fittings.
A cooling device for an electronic component is specified, which is built up from a stack (1) of profiled plates (2a; 2b) lying on one another and connected to one another and, at the end of the stack, termination plates (3) are provided in the stacking direction (x), at least one of the termination plates (3) being designed to make extensive contact with the electric component. Furthermore, at least one of the profiled plates (2a) has a flexible extension (4), the extension (4) projecting beyond the cross section of the stack (1). In addition, a cooling system with at least two such cooling devices is disclosed.
A flexible laminated jumper is formed from a stack of half hard tempered copper sheets. Contact plates are clamped to opposite sides of one end of the stack, such plates being provided with short stress relief sections away from the end of the stack. The clamped end is positioned properly in a press welder so that the flat portion of the contact plates are gripped by graphite electrodes of a press welder. The gripped end of the stack is then press welded while the balance of the stack is cooled so that the heat from the press welding does not affect the temper of the sheets of the stack. This is preferably done by immersion in chilled water with the water level being in close proximity to the electrode. After the press welding, the entire stack is cooled and the still tempered stack is formed to the desired configuration. The application of the contact plates and press welding of the opposite end of the stacks is repeated, again with the balance of the stack isolated from the heat of the press weld to protect the temper. After cooling and final trimming, machining, cleaning and silver plating, the jumper is completed. Such jumpers form, for example, improved spot welding gun shunts which have lower resistance levels which improve the efficiency of the spot welding process and cooler shunt operating temperatures which not only provide longer shunt life, but more consistent quality, since the shunt resistance does not change over time.
A flexible laminated jumper is formed from a stack of half hard tempered copper sheets. Contact plates are clamped to opposite sides of one end of the stack, such plates being provided with short stress relief sections away from the end of the stack. The clamped end is positioned properly in a press welder so that the fiat portion of the contact plates are gripped by graphite electrodes of a press welder. The gripped end of the stack is then press welded while the balance of the stack is cooled so that the heat from the press welding does not affect the temper of the sheets of the stack. This is preferably done by immersion in chilled water with the water level being in close proximity to the electrode. After the press welding, the entire stack is cooled and the still tempered stack is formed to the desired configuration. The application of the contact plates and press welding of the opposite end of the stacks is repeated, again with the balance of the stack isolated from the heat of the press weld to protect the temper. After cooling and final trimming, machining, cleaning and silver plating, the jumper is completed. Such jumpers form, for example, improved spot welding gun shunts which have lower resistance levels which improve the efficiency of the spot welding process and cooler shunt operating temperatures which not only provide longer shunt life, but more consistent quality, since the shunt resistance does not change over time.
