Abstract: The invention relates to a mechanical switching contact for bipolar commutation comprising an insulating support having fixed contacts disposed therein. Said contacts are switchable by means of a contact carrier which possesses a pivoting arm on the free end and thereof with a respective conducting contact element. The whole mechanical switching contact is configured as a modular unit which can be assembled in an optional manner.

Abstract: A load switch has a housing, a pair of main contacts fixed in the housing, and a movable main contact pivotal on the housing between end positions in each of which it engages a respective one of the fixed contacts and through a middle position in which it engages neither of the fixed contacts. A central shaft extending along an axis and pivotal in both directions thereabout carries a cam having offset from the axis a cam formation. A mechanical link engaged between the cam formation and the movable contact can pivot it between its end positions and through its middle position on rotation of the cam about the axis.

Abstract: An on-load tap changer of a step switch has a force-storage unit which has a charging slide continuously movable by a bidirectionally rotatable drive shaft and an output part that when tripped suddenly follows the movement of the charging slide and rotates a switching shaft. Respective switches for each phase are each actuatable by respective actuating elements that coact with edges of respective concentric cams rotatable by the switching shaft. An axially movable switching unit is mounted on the switching shaft and the switching unit carries cam disks for actuating the switches, each cam disk being subdivided into an upper and a lower subdisk with different shapes. The switching unit is movable in a direction dependent on the rotation direction of the drive shaft into an upper or a lower position.

Abstract: The invention concerns a switching arrangement for load change-over switches of step switches and for selector switches, wherein two switching contacts movable in two directions are present. The first switching contact is in the form of a main switching contact and is connected to the load derivation by means of a first vacuum switchgear cell. The second switching contact is in the form of a resistance switching contact which is likewise connected to the load derivation by means of a series connection comprising a second vacuum switchgear cell and a transition resistor. Both the main and the resistance switching contacts can be moved independently of one another and without mutual coupling or influence. The main switching contact always reaches the new fixed contact abruptly and independently of the switching direction before the resistance switching contact leaves the previous fixed contact.

Abstract: A step-transformer drum formed with throughgoing apertures each centered on a respective axis has a contact assembly in each aperture having an insulating washer lining the aperture and having an inside part lying on an inside surface of the drum and an outside part lying on an outside surface of the drum. A stud has an enlarged head bearing outward on the inside washer part and a shaft projecting through the washer past the outside washer part and formed outside the outside washer part with a transversely throughgoing hole. A pin extends transversely through the hole and bears inwardly on an outwardly directed ramp so that rotation of the stud and pin in one direction relative to the structure makes the pin ride up on the ramp and tightens the stud in the aperture and opposite relative rotation loosens the stud.