Abstract: The switching device has a fixed contact which cooperates with a movable contact secured to a movable contact carrier. The contacts are connected to runner rails for the arc that is created upon the contact opening. The runner rail connected to the movable contact consists of a movable commutating conductor which, during the initial stage of the contact opening, is at least approximately stationary, and then moves together with the movable contact to the open position of the switching device.

Abstract: To reduce hysteresis effects on the output of a magnetoelastic torque transducer subjected to possible overloads, the transducer is constructed with a measuring sleeve which is rigidly attached by its ends to a surrounded measuring axle. A yielding region in which the material of the sleeve deforms plastically relative to the axle in case of an overload is provided between the measuring zones where the magnetoelastic stresses in the measuring sleeve are sensed. A ring of holes can provide a suitable yielding region.

Abstract: A method by which a turbine generator (1, 2, 3) can be protected against sub-synchronous frequencies occurring in an electric network which is connected to the turbine generator and which incorporates capacitors. The method is based on de-equalizing the subsynchronous natural frequencies of the three phases, so as to weaken the coherence of the frequencies. This is achieved by incorporating in each of two of the phases a respective inductance L of mutually different size and by changing the capacitance equivalently with a series capacitance C such as to fulfill the condition 1/LC=.omega..sub.o.sup.2, where .omega..sub.o is the network frequency.

Abstract: For stirring molten metal in continuous casting at least two stirrer members are placed outside the mold on opposite sides thereof, the stirrer members being provided with iron cores and surrounding coils. Intermediate iron cores can be arranged between the stirrer members to form a closed magnetic circuit around the mold, whereby horizontal rotation of molten metal in the strand can be achieved.

Abstract: A device in an industrial robot permitting rapid exchange of tools in spite of the fact that the tools require both electric and pneumatic operating pulses. The robot hand supports a housing and a tool holder attachment rotatably journalled in the housing, a tool holder being detachably arranged in the tool holder attachment. An automatically breakable electrical connection is provided between the housing and the tool holder by means of slip rings, arranged either on the housing or on the tool holder, and collector shoes, making contact with the slip rings, on the corresponding tool holder or housing.

Abstract: The reactance of series capacitor equipment connected to an electrical transmission power line can be changed during operation with the aid of a transformer on-load tap-changer which switches in or out a variable number of capacitor modules. The tap-changer comprises a tap selector, the contacts of which in currentless state can be moved between the capacitor steps, and a diverter switch with a plurality of sequentially operating contact members and with resistors arranged to prevent direct short-circuiting of the capacitor steps. The tap-changer can be at line potential and operated remotely by contact-moving means at ground potential.

Abstract: A magnetoelastic force transducer comprising two identical, cylindrical bodies defining a hollow magnetic core and held together by means of a force-transmitting stud bolt has its measuring and excitation windings located in the core. The interior of the core is constructed such that a thin cylindrical tubular wall is formed opposite to a respective measuring winding in each one of the bodies, whereby when the core is force-loaded via the stud bolt a compressive stress arises in one of these tubular walls and a tensile stress arises in the other. To eliminate a possible measurement signal at zero applied force a magnetically asymmetric center pole in the form of a punched disk of a soft-magnetic material and having the same diameter as the core and having a foil of a similar material secured on one side is located between the bodies. The hickness of the foil determines the magnitude of the signal adjustment.

Abstract: In connection with synchronous closing or opening of three-pole circuit breakers, the desired time shift between the instants of contact make or contact break in the different phases can be achieved mechanically by a suitable choise of arms and links in the mechanical system interconnecting the contacts and the operating device. The necessary time difference between the instants of switching, with retained positions of open and closed contacts, can be achieved in mechanism with a toggle joint (4, 51) which is extended to a greater or smaller extent in the three poles.

Abstract: An electrically controlled spring element according to the invention comprises one or more basic spring elements and a mechanical transformer to increase the stretch of the spring element. The basic spring element comprises two mechanically connected elements with an intermediate transmission for power output, each of the elements consisting of a rod pre-magnetized by permanent magnets and consisting of highly magnetostrictive material (Terfenol), a surrounding excitation coil and an outer frame holding the parts together. The magnetic orientation of the pre-magnetization and the coils shall be such that, regardless of the direction of the control current, the electrically controlled excitation is always directed in the same direction as the pre-magnization in one element and is always directed in the opposite direction to the pre-magnetization in the other element.