Bbc Brown, Boveri & Company, Limited

Wolfgang Widl

Lutz Niemeyer

Gernot H Gessinger

Imre Horvath

Renata Sebalj

Wilhelm Nurck

Heinz-Peter Kirchesch

The arc withstanding electrodes in an electric circuit breaker for switching high voltages attain greater mechanical strength and improved arc withstanding capabilities by forming the arc withstanding electrodes of a carbon-fiber-reinforced-graphite material which material is constituted of a graphite matrix which is reinforced by carbon fibers embedded therein. A method for forming the carbon-fiber-reinforced-graphite of the arc electrodes and for affixing the arc electrodes to a metal carrier therefor includes the steps of employing a high-temperature solder based on copper and/or silver, containing at least one carbide-forming element such as, for example, Cr.

Arcing contact tip and method for producing such an arcing contact tip

A switch, preferably for switching medium voltages, includes a structure which creates a gas-blast to quench an arc drawn between two separating contact pieces of the switch. The gas-blast is created solely by the quenching gas which is heated by the arc, without auxiliary pressure creating mechanisms. The gas blast is sufficiently powerful to cut off high and low currents without use of pressure-controlling valves. The result is realized via a flow-off pipe located between a space where the arc develops and a gas exhaust space. One end of the flow-off pipe opens into the exhaust space. The size of the flow-off pipe is determined in part by the speed of propagation of a pressure wave which is formed in the arc space during the heating phase of the arc and the length thereof is deliberately selected such that the pressure gradient between the heated quenching gas and the arc space is maximized.

Gas-blast switch

A compressed-gas breaker having a magnetic coil through which the breaking current flows, has two coaxial contact members which are movable with respect to each other along a central axis and have in each case one arcing contact. The arcing contacts are surrounded by a heating chamber which is joined to the arc volume located between the separated burning contacts during breaking. In this breaker, the breaking capacity is to be improved by a simple means. This is achieved by the fact that between the heating chamber and the arc volume a gas-guiding device is provided which has at least three ducts which are arranged to be distributed azimuthally around the axis. These ducts have sections which open radially with respect to the axis into the arc volume. Such a breaker can be used preferably for the switching of large current of medium-high voltage.

Growing community of inventors

Glattbrugg, Switzerland

Wolfgang Widl