Abstract: The invention relates to a contact assembly mounted on a preselector of a step switch, where the fixed preselector contact has a contacting ring that can be interconnected. The appropriate design of the contact and of the openings in an insulating material housing, in which said contact should be fixed, as well as an additional positioning part enable a simple mounting and a reliable fixing which simultaneously prevents turning.

Abstract: The invention relates to a load selector for step switches in step transformers with two movable selector contacts. A suitable vacuum switch is located downstream of the first movable selector contact to switch the load current and a suitable switch for switching the compensation current is located downstream of the second movable selector contact. Both of the selector contacts are independently movable in such a way that one of the selector contacts moves slowly and the other selector contact rapidly moves or jumps between positions. The sequence of operation of the selector contacts is independent of the switching direction.

Abstract: A force-storing actuator for connection to a rotor of a step transformer has a central upright axle connected to the rotor and rotatable about its axis, and upper and lower input wheels fixed rotationally to each other and rotatable on the shaft about the axis. Respective upper and lower drive elements fixed underneath and atop the input wheels flank upper and lower force-storing levers rotatable on the shaft between the input wheels and juxtaposed with the input wheels. Each lever is angularly engageable with the respective drive element. A spring has outer ends connected to the two levers offset from the axis. An output wheel fixed on the shaft above the upper input wheel carries an output element fixed on the shaft axially between the levers and engageable angularly with both of the levers.

Abstract: A force-storing actuator for connection to a rotor of a step transformer has a pair of similar levers rotatable about a common axis and having diametrally opposite outer ends, an input element and an output element rotatable about the axis and operatively engageable with the levers, and a latch device for releasably retaining the output element in any of a plurality of angularly offset positions. Respective springs each have one end connected to a respective end of one of the levers and an opposite end connected to a respective end of the other lever and having a middle between the ends. Respective guides movable freely angularly about the axis between the lever ends at generally the same radial spacing from the axis as the lever ends are connected to the middles of the respective springs. Thus the springs each have a pair of sections flanking the respective guide and extending generally tangentially of a circle centered on the axis from the respective spring ends to the respective spring middles.

Abstract: A bridge-contact assembly used in combination with an inner contact ring and a contact terminal of an array concentrically surrounding the ring comprises a contact hoousing rotatable concentrically with and between the ring and array, a pair of bridge-contact jaws extending between the ring and the array and having inner ends gripping the ring and outer ends gripping a one of the terminals of the array, and a contact holder spacedly surrounding the pair of jaws and spacedly surrounded by the contact housing. At least one jaw spring supports the jaws in the holder and urges the jaws together and at least one holder spring supports the holder in the contact housing.

Abstract: A multiphase under load transfer switch of the Jansen-type for tapped regulating transformers. The main contacts and the switch-over contacts of the transfer switch are formed by vacuum switches. The vacuum switches are operated by a common drive mechanism for all of the vacuum switches of all three phases of the transfer switch. The required sequence of the operation of the vacuum switches is achieved by interposition of lost motion connection means between said common drive mechanism and pairs of aligned operating rods for pairs of superimposed vacuum switches. A special common drive mechanism for said pairs of aligned operating rods for operating pairs of superimposed vacuum switches includes a squirrel-cage-like system of helical compression springs which are loaded by pivotable cam means and operate, when subsequently expanding, said pairs of vacuum-switch-operating rods by the intermediary lost motion connection timing means.