Abstract: A method for interrupting an inductive load in a three-phase, high voltage network by means of a switch having a quick dielectric recovery, in particular a vacuum switch, in which two of the three vacuum switches, having a quick dielectric recovery, open at least 1/3 of a cycle of the network frequency later than the first vacuum switch, augmented with the minimum arcing time in the first vacuum switch, in order to prevent high over-voltages, caused by virtual chopping.

Abstract: Active full-wave rectifier circuit for a current transformer used for example in an earth leak detector circuit and comprising active components such as operational amplifiers and transistors to detect and process relatively weak output voltages.

Abstract: The present invention relates to an apparatus for moving an element, for instance a movable contact of a switch, from a first end position to a second end position and vice versa and selectively keeping the element in each of the noted end positions, the apparatus comprising an energy buffer (1), for instance a spring, mechanically coupled with the element, which can be in two stationary end conditions corresponding with the noted end positions, or in intermediate translation conditions in which potential energy is transduced into kinetic energy and vice versa, a mass (4) driven by the energy buffer (1) which can be moved to one of two end positions corresponding with the end conditions of the energy buffer, and a locking mechanism (8, 34, 31) for locking the mass (4) in its end positions.

Abstract: Electric current is limited in a current interruption device including two stationary contacts with terminals and a bridging contact movable toward and away from a position bridging the stationary contacts by a conductor connected to each of the stationary contacts and an interconnection of the ends of the conductors remote from the stationary contacts to provide a parallel current path other than the current path for the arc with the current being interrupted when the bridging contact moves away from its bridging position at a value of the current flowing through the conductors such that upon interruption of the current therethrough the voltage across the stationary contacts is sufficient to generate an arc therebetween with the arc travelling along the conductors away from the stationary contacts by the magnetic field generated from the current flowing through the conductors.

Abstract: A tubular shaped high voltage fuse, with a support tube of insulating material, having applied thereon parallel fuse conductors, and an outer tube of insulating material, surrounding the support tube. The end cap consists of a cup-shaped electrically conducting cap to be placed upon the ends of the support tube and the outer tube, a tore-shaped, closed helical contact spring of electrically conducting material to be placed around the support tube end for connecting the fuse conductors with the cap and a spacing piece of insulating material having resilient strips connected therewith for compensating tolerance deviations and for centering, together with the helical spring, the support tube within the outer tube.

Abstract: The invention relates to an assembly for a current limiting high voltage fuse, comprising a preferably tubular support body (1), consisting of quartz glass, and fusible conductors (2) attached over their entire length to the support body, which conductors (2) are of a width of minimum 0.5 mm and maximum 1 mm and of a thickness of maximum 50 .mu.m.These fusible conductors are applied in parallel paths, the distance between the paths being at least twice as large as the width of the fusible conductors. Also the fusible conductors are provided with narrow sections (4) separated in longitudinal direction of the fusible conductor over regular distances, and interconnected at both ends by an electrically conducting sleeve (3) applied to the support body (1).

Abstract: Device for moving an element between two end positions and for selectively holding this element alternately in one of these positions, comprising an energy buffer mechanically coupled with this element, which buffer may be in one of two corresponding stationary end states, in which the energy is present in the form of potential energy, and in intermediate translation states, in which potential energy is transformed in kinetic energy and vice versa, a mass driven by the energy buffer and moved to one of the two end positions, and locking means for each of the two end states of the energy buffer. According to the present invention the mass is movable elastically over a predetermined distance with respect to the energy buffer and with respect to the element, so that when the element reaches one of its end positions the mass can move further over a predetermined distance towards its end position, thus transforming all kinetic in potential energy.

Abstract: Method for vacuum-tight butt joining by brazing a stainless steel part to a ceramic part, in particular stainless steel end caps to a ceramic housing of a vacuum switch, in which the stainless steel part is annealed prior to the brazing step and the portion of the stainless steel part directly adjoining the ceramic part at the brazing joint location is of a thickness not exceeding 0.8 mm and a height between about 4 and 12 mm.

Abstract: In a selective safety device for the protection of successive power levels in a power distribution system, a current limiting switch is provided in each of the power levels and includes a current-limiting quick-switching contact which is so positioned at the power supply side in each one of the different power levels such that the current limiting switch immediately in front of a fault is switched off upon occurrence of a fault. A resistor is connected across each of the quick-switching contacts and is serially connected in the interrupted circuit upon the opening action of the quick-switching contact. Additionally, a slow-switching contact is serially connected with each of the quick-switching contacts to be opened after opening of the quick-switching contact with a presettable delay time, which is dependent upon the power levels in which the slow-switching contact is connected.

Abstract: A vacuum switch comprising a vacuum tight envelope accommodating in vacuum contacts mounted on current carrying contact rods and capable of movement with respect to each other as well as a getter device, comprising a getter element provided with a getter material which may absorb optionally present gases upon evaporation thereof by the application of heat generated by an induced current, a metal shield arranged between the getter device and the insulated walls of the vacuum switch, said shield functioning as the surface on which the getter material is deposited and being provided with slots preventing the occurrence of eddy currents in the shield and in that the getter element emits the getter material by evaporation at a single location only, this location and the location of the slots in the shield are situated with respect to each other in such a manner that the contact rod carrying both the getter device and the shield will keep the getter material from emanating beyond said shield.

Abstract: Method for improving switch contacts in particular enhancing the voltage endurance, lowering the chopper level and improving the electrical conductivity for the use in vacuum switches in which ions are implanted of material improving the above said characteristics, at least in the surface area of the switch contacts where upon switching action a discharge is generated.

Abstract: Current limiting switch for rapid circuit breaking, including at least one pair of contacts, one contact being mounted stationary and the other being mounted on a movable arm. The contact arm is rotatable about a fixed point upon surpassing a predetermined current threshold value, by means of an electromagnet energized by the current passing through the switch. The electromagnetic means comprise an electromagnet and a first and a second armature cooperating with the electromagnet, in which the first armature drives the movable contact in the direction of disengagement and the second armature releases a locking device, which blocks the movable contact in the direction of movement until the current threshold is reached.

Abstract: Current measuring system particularly suitable for use as an earth leakage detection system and functional device equipped with such a system e.g. an earth leakage switch.

Abstract: A high tension vacuum switch, comprising two relatively axially movable switching contacts and two annular electrodes for shielding the open contacts from excessive electric field, in which each shield is associated and electrically coupled with a respective one of said switching contacts and projects slightly beyond the contact surface of said contact in the direction towards the other switching contact to provide the field-shielding effect when the contacts are open. At least one of the shielding electrodes is not directly connected electrically but is only capacitively coupled with its respective switching contact so as to add the advantage of much smaller overall dimensions for a switch of this kind.

Abstract: Electrical vacuum switch having two contact members carried by contact rods for moving the contact members in and out of engagement with each other, in which each contact rod is partly surrounded by a yoke of magnetic permeable material, closely adjacent each contact member, each yoke leaving a gap between the yoke legs, so that upon moving the contact members out of engagement, the magnetic flux lines, generated in each yoke by the current through the contact rods, will traverse the arcing gap between the contact members, towards the opposing yoke, resulting in a magnetic field in the arcing gap.

Abstract: A contact device for interconnecting an electrically energized rail with a removable contact finger mounted on a movable vehicle includes a hollow housing and two cooperating contact members therein, the contact members being mounted in a hinge-like fashion so as to be mirror images of one another, one set of cooperating ends contacting the removable contact finger and the other set of cooperating ends contacting the insides of the spaced-apart walls forming the rail.

Abstract: In a contact device for the transmission of electric current between a stationary contact and a movable contact wherein the stationary contact has walls at least partially encircling the movable contact, resilient elements transmit the current and are positioned between the movable contact and the walls of the stationary contact. The resilient elements comprise roller contact springs made of a material having sufficient electrical conductivity, elasticity and mechanical strength and are wedged in between the movable contact such that upon movement thereof the contact springs revolve about their center. The springs have a diameter larger than is necessary to span the distance between the movable contact and the walls of the stationary contact, and the roller contact springs are reduced in diameter by twisting or torsioning.

Abstract: An actuation device which includes a holding magnet, an attracting magnet and an armature therebetween, both magnets being excitable by the same electromagnetic source. The armature comprises two half portions interconnected by a non-magnetic plate and operating such that upon saturation of the holding magnet with current, the armature will be disengaged by the holding magnet and drawn towards the attracting magnet.

Abstract: A spring-drive mechanism for controlling the switch-on and switch-off positions of contacts of an electric switch wherein the conventional lever system for relaying the rotating force from the helical spring to the contacts is replaced by a structure which includes a fixed hollow cylinder in which a movable coupling shaft is located, the hollow cylinder having axially staggered wall bores in which balls are positioned, the configuration and positioning of the coupling shaft within the hollow cylinder determining whether one or the other of the balls is positioned to extend outwardly of the outer surface of the cylinder. The hollow cylinder is positioned with one end of a hollow shaft which coaxially encompasses a drive shaft and helical spring combination, the structure including interconnecting projections to provide for selective rotational interengagements between the hollow shaft and the drive shaft.

Abstract: Electrical vacuum switch having two contact members carried by contact rods for moving the contact members in and out of engagement with each other, in which each contact rod is partly surrounded by a yoke of magnetic permeable material, closely adjacent each contact member, each yoke leaving a gap between the yoke legs, so that upon moving the contact members out of engagement, the magnetic flux lines, generated in each yoke by the current through the contact rods, will traverse the arcing gap between the contact members, towards the opposing yoke, resulting in a magnetic field in the arcing gap.