Abstract: Each bimetallic element is associated with one phase and is attached with one end thereof to a metallic support mounted at a wall of a housing. Each support comprises two supporting surfaces or faces lying in a plane which extends at right angles to the bending or deflection direction of the free ends of the bimetallic elements. When all the bimetallic elements have the same temperature, the distance of this plane from the bendable ends of the bimetallic elements is the same for all bimetallic elements. The supports are supported at counter surfaces or faces provided at the housing wall via a plate-shaped intermediate layer of the same thickness. The counter surfaces for all supports lie in a common plane extending at a distance, which corresponds to the thickness of the intermediate layer, from the plane defined by the supporting surfaces and in substantial parallelism thereto.

Abstract: At the underside of a substantially U-shaped support or carrier formed of steel there is affixed an intermediate element or part formed of an electrically conductive material, for instance copper or a copper alloy. This intermediate element carries at its bottom face or surface two contact supports or members formed of a suitable material, for instance AgCdO. At the ends or end faces of the U-shaped support there are attached arc conducting elements formed of a ferromagnetic material, for instance steel. The arc conducting elements protrude away from the base portion of the U-shaped support in the direction of the contact supports and extend laterally thereof up to the region of their contact surfaces. The arcs arising during contact opening directly transfer or shift from the contact surfaces to the arc conducting elements, without the arc base points migrating laterally from the contact supports to their connection locations.

Abstract: A gas-blast switch or circuit-interrupter contains a fixed set of contacts and a movable set of contacts. Each contact set possesses an arc contact and a rated current contact coaxially surrounding the related arc contact. Operatively associated and co-movable with the movable contact set is a blast nozzle which surrounds the arc contact of such movable contact set. In the cut-on position the blast nozzle is closed by the fixed arc contact and is operatively connected with a pressure chamber which can be pressurized during a cut-off stroke. At the outflow end of at least one of the arc contacts there are arranged means in order to axially and outwardly deflect the switching gas flowing-out of such end during the cut-off stroke.

Abstract: A current transformer having at least one ring-shaped core with a secondary winding mounted thereon, and a primary conductor, located within its casing. An inner tube is provided between the ring-shaped core and the primary conductor, one end of the tube being electrically connected to the casing and its other parts electrically insulated therefrom. A cylindrical, electrically conductive screening shield at least partially overlaps the inner tube and is electrically connected to the casing on the side of the ring-shaped core which is distal from the electrical connection between the casing and the inner tube, while the other parts of the shield are electrically insulated from the casing. This overlap forms a short-circuit loop for any steep progressing wave which is generated when switching on a potential-free part of the circuitry, or when due to an interruption, a small capacitive current breaks off.

Abstract: At least one primary switch position is connected in parallel with a series circuit composed of an auxiliary switch position provided with a cut-on or switching-in resistor. By means of a respective one of two lever drives each switch position is operatively coupled with a drive rod movable between a cut-on position and a cut-off position. The lever drive correlated to the primary switch position is provided with a double-arm lever which is pivotable about a stationary shaft. The double-arm lever is coupled at its one end to the drive rod and at its other end is coupled to a movable switching element of the primary switch position. The lever drive correlated to the auxiliary switch position is constructed such that during a cut-on stroke the auxiliary switch position initially is closed and at the end of the cut-on stroke such is reopened.

Abstract: A movable contact element is surrounded by a co-movable blast nozzle which in the cut-on position is closed by a stationary contact element which is in engagement with the movable contact element. At its inlet side the blast nozzle is flow connected with a pump chamber or compartment which can be pressurized during the cut-off stroke. This pump chamber is constructed in a jacket or shell chamber-like fashion and bounded by an inner cylinder and an outer cylinder. The inner cylinder carries the movable contact element and the outer cylinder carries the blast nozzle. Both cylinders are displaceable by means of a stationarily supported pump piston. In order to prevent any obstruction to the flow of the extinguishing gas which is effluxing out of the pump chamber during the cut-off stroke, both of the cylinders are solely connected with one another at their ends facing away from the blast nozzle by means of a substantially ring-shaped floor member which is preferably formed at both cylinders.

Abstract: A plastic mass of a blast nozzle contains a filler which is at least partially composed of powder of one or more metals. The proportion of metal powder amounts to at most 30 percent by weight, preferably 5 to 15 percent by weight. As the filler there is particularly suitable, alone or in combination, the metals of tungsten, copper, aluminum and iron. The electrically conductive filler prevents penetration of the electromagnetic radiation emanating from the arc into the interior of the blast nozzle, resulting in an appreciable reduction in nozzle burn-off.

Abstract: The gas blast switch of the invention has an insulating housing which is divided into an arcing enclosure for an auxiliary arc intended to build up the pressure, a storage enclosure for storing fresh quenching gas, a quenching enclosure meant for the quenching of the main arc, and an expansion enclosure. An axially movable insulating follower piston is provided within the fixed contact piece. During switching-on, it is pushed into its resting position through the action of the movable contact piece and against the force of a spring. During switching-off, it will follow the movable contact piece until the latter leaves the dividing wall, whereupon the piston stops, thus closing the aperture in the dividing wall which connects arcing and quenching enclosures. An electrically conductive ring forms the mouth of the aperture and acts as an arcing electrode between the auxiliary arc and the main arc.

Abstract: A drive element coupled with a mechanical drive is guided out of a switch housing through a through-passage housing containing a liquid bath. In the liquid bath there is immersed a hydraulic damping device containing a cylinder and piston and cooperating with said drive element, so that, with virtually no additional constructional expenditure at the drive, there is achieved a dependable braking of the drive element towards the end of a switching stroke. The piston of the hydraulic damping device is connected by means of a drag connection with the drive element. This drag connection includes at least one entrainment rod connected with the piston and acted upon by an entrainment collar provided at the drive element.

Abstract: In the cut-on position of the protective switch a movable contact element engages with a stationary contact element and at the same time is exposed to the action of a force displacing such movable contact element into a cut-off position. The movable contact element is arrestable in the cut-on position by means of a locking device which can be activated by an excess current. In order to reduce the number of movable parts to a minimum as well as to avoid parts which generate heat due to appreciable thermal losses, such locking device is provided with a substantially U-shaped locking element formed of a soft magnetic material. This locking element surrounds the movable contact element with play or clearance and is displaceably mounted transversely with respect to the flow of current in such movable contact element. At least one free leg end of the locking element is provided with a stop which in the cut-on position cooperates with a stop nose which is movable together with the movable contact element.

Abstract: A movable contact element is secured at the end of a thrust rod and therefore can be brought into and out of engagement with a fixed contact element. The free end of the movable contact element is surrounded by a blast nozzle which is likewise secured to the thrust rod. The inlet of the blast nozzle is operatively connected with a pump chamber containing an extinguishing gas and which can be pressurized during the course of a cut-off stroke of the gas-blast switch. This pump chamber is surrounded at its circumference by a cylinder which is displaceably guided upon a stationarily supported piston. To reduce the mass of the parts which are to be accelerated at the start of the cut-off stroke, the blast nozzle itself is constructed as a second piston situated opposite the first-mentioned piston and displaceable relative to the cylinder between two end positions.

Abstract: A gas-blast switch provided with two coaxially arranged contact elements which can be brought into and out of engagement with one another by carrying out an axial movement. The first contact element which is connected with a drive is arranged in a fixed reference position forwardly of a blast nozzle. The blast nozzle is connected at its inlet side with a compression chamber or space which can be pressurized during the cut-off stroke of the gas-blast switch. In the cut-on stroke of such gas-blast switch the second contact element engages with the blast nozzle. The second contact element is surrounded by a screening body which, in turn, can be shifted back by means of the blast nozzle, during a cut-on stroke of the gas-blast switch, out of its advanced position in the cut-off position, against the action of a spring, along the second contact element.

Abstract: The resistance of insulating pieces made of fiberglass reinforced plastics against the decay products of SF.sub.6, such as occur within sealed high-voltage switching devices is unexpectedly enhanced by the use of a reinforcing fiberglass made of a low-alkali silicate glass containing neither boron nor boron-compounds.

Abstract: A movable, tubular-shaped contact element is displaceably guided in a partition wall subdividing the internal space of the gas-blast switch housing into an extinguishing chamber and an expansion chamber. During the cut-off stroke a current connection prevails by means of this contact element between both of the chambers or compartments. The contact element coacts with a stationary or fixed contact set having a rim of rated current contacts which, in the cut-on position, engage about the contact element. Further, there is provided a burn-off ring which is electrically connected with the contact element and has an electrically insulated, suspended intermediate electrode which, in the cut-on position, engages into the contact element or piece. The latter, during the cut-off stroke, initially comes out of engagement with the rated current contacts and first thereafter comes out of engagement with the intermediate electrode.

Abstract: A fixed contact element and a movable contact element can be brought into and out of engagement with one another within a switching chamber. The switching chamber flow communicates, on the one hand, by means of a blast nozzle, closed by the movable contact element in the cut-on position of the gas-blast switch, with an expansion chamber and, on the other hand, flow communicates by means of a check or a non-return valve which opens in the direction of the switching chamber, with the pressure side of a pump cylinder arranged in the expansion chamber. Operatively associated with the pump cylinder is a movable pump piston which pressurizes the pump cylinder during a cut-off stroke with a time-delay.

Abstract: A movable contact element is coupled by a step-up lever drive with a drive rod. The movable contact element is surrounded by a blast nozzle which moves along with the movable contact element. The blast nozzle is connected to a pump cylinder containing an extinguishing gas. The pump cylinder is guided to be vertically displaceable upon a pump piston and this pump piston is hingedly connected with one end of a first element of a toggle lever which in the cut-on position is in its bent position or mode, the second element of the toggle lever being hingedly connected at a stationary location. The toggle joint of the toggle lever is likewise coupled with the drive rod, so that during a cut-off stroke the toggle lever is extended and then again bent.

Abstract: A gas-blast switch containing a stationary and a movable contact element. A blast nozzle associated with one of the contact elements possesses a blast channel, which during the course of the cut-off stroke, is freed from the other contact element. Additionally, there is provided a blast-in opening, transversely arranged with respect to the extinguishing path and opening into the blast channel. The blast-in opening has a flow cross-section which is appreciably smaller than that of the blast channel. Both the blast channel and the blast-in opening flow communicate with a pump compartment containing an extinguishing gas and which can be pressurized by the cut-off stroke of the switch.

Abstract: A gas-blast switch having a pump cylinder conjointly movable with a movable contact element, the pump cylinder enclosing a pump chamber containing extinguishing gas and feeding a blast nozzle. Within the pump cylinder there is movably arranged a pump piston which, during the course of the cutoff stroke, displaces the extinguishing gas out of the pump chamber through the blast nozzle. In order to utilize the drive energy at the start of the cutoff stroke extensively for accelerating the movable switch elements and to somewhat delay in time the compression of the extinguishing gas in the pump chamber, likewise requiring the drive energy, there is hingedly connected at the pump piston one element of a toggle lever which is fixedly hinged at its other element and assumes a bent position in the cuton position. The toggle lever is guided by a guide element coupled with the movable contact element.

Abstract: A gas-blast switch containing both a stationary and a movable contact element. At one of these contact elements there is arranged a blast nozzle whose inlet chamber or compartment is connected with the outlet of a pump chamber containing an extinguishing gas and which can be placed under pressure during the cutoff stroke. Between the inlet chamber of the blast nozzle and the pump chamber there is a valve arrangement which is pre-biased in the closing direction. The valve arrangement responds when there is an excess pressure in the pump chamber and opens in the direction of the inlet chamber or compartment.

Abstract: A gas-blast switch having a movable contact element and a stationary contact element and a blast nozzle operatively associated with one of the contact elements and surrounding the same. The blast nozzle, during the course of the cut-off stroke of the gas-blast switch, is connected with a pump chamber or compartment which can be placed under pressure. The nozzle chamber is constituted by an inlet space converging towards the nozzle throat and an outlet space diverging away from such throat. In the blast nozzle there are additionally formed channels which flow communicate with the pump chamber. These channels open at an angle with respect to the nozzle axis into the nozzle chamber in order to additionally cause a blowing of the arc transversely in addition to the axial blowing of the arc in the blast nozzle.