The invention concerns a double-motion circuit breaker comprising primary and secondary movable contacts slidingly mounted within primary and secondary holders, wherein the primary movable contact comprises a tulip and a contact cylinder attached thereto, and the secondary movable contact comprises a pin for engaging the tulip but no counter-contact for engaging the contact cylinder. The circuit breaker also has a non-linear linkage mechanism with a pin and slot mechanism, and a fixed dielectric shield provided on the secondary holder. During disconnection, the linkage mechanism is preferably arranged to move the pin more than the tulip, proportionally to their maximum stroke, so as to quickly bring the pin tip within the fixed dielectric shield, whereafter the tulip moves more than the pin. This circuit breaker is cheaper, lighter and can be disconnected more quickly.

An internal tulip sleeve for the female arcing contact of a high voltage circuit breaker. According to the invention, this sleeve comprises a body of non-magnetic steel or of copper-tungsten alloy, this body comprising an internal face covered with copper.

A high-voltage device has an encapsulation housing and at least one bushing for at least one conductor, through which a current flows, into the encapsulation housing and/or out of the encapsulation housing. At least one electrode at free potential is surrounded by the bushing. The at least one electrode at free potential increases the dielectric strength in the high-voltage device, especially in the region of the bushing.

An interruption switch is provided for interrupting high currents at high voltages, with a casing, which surrounds a contact unit defining the current path through the interruption switch which has a first and second connection contact and a separation region. The contact unit is formed such that a current can be supplied to it via the first connection contact and can be discharged therefrom via the second connection contact, or vice versa. The separation region is formed such that, when it is separated, the current path between the first connection contact and the second connection contact is interrupted. The separation region is arranged inside a reaction chamber. A coating with a reactive material is present in the reaction chamber. The reactive material is designed such that under the influence of an electric arc it attenuates or extinguishes the electric arc.

An interruption switch is provided for interrupting high currents at high voltages, with a casing, which surrounds a contact unit defining the current path through the interruption switch which has a first and second connection contact and a separation region. The contact unit is formed such that a current can be supplied to it via the first connection contact and can be discharged therefrom via the second connection contact, or vice versa. The separation region is formed such that, when it is separated, the current path between the first connection contact and the second connection contact is interrupted. The separation region is arranged inside a reaction chamber. A coating with a reactive material is present in the reaction chamber. The reactive material is designed such that under the influence of an electric arc it attenuates or extinguishes the electric arc.

The present invention relates to a process for treating a polyamide-based material comprising silica fibers and/or fillers, by impregnation with at least one hydrophobic additive in supercritical CO.sub.2. The invention also relates to a polyamide-based material comprising silica fibers and/or fillers and impregnated with at least one hydrophobic additive, obtained via such a process, and to the use thereof as an electrically insulating component in an electrical device, in particular in a circuit breaker.

The present invention relates to a process for treating a polyamide-based material comprising silica fibers and/or fillers, by impregnation with at least one hydrophobic additive in supercritical CO.sub.2.

The invention also relates to a polyamide-based material comprising silica fibers and/or fillers and impregnated with at least one hydrophobic additive, obtained via such a process, and to the use thereof as an electrically insulating component in an electrical device, in particular in a circuit breaker.

The present disclosure relates to switchgear. Various embodiments may include medium- or high-voltage switchgear with a gas-tight insulating space. For example, a switchgear may include: a gas-tight insulating space where an insulating gas is kept above atmospheric pressure and two switching contacts in the space. At least one of the contacts may movable with respect to a nozzle. The insulating gas may include a mixture of at least 90% by mass of nitrogen and oxygen or nitrogen and carbon dioxide. The nozzle may include a plastic with at least 65% by mass in total of the elements carbon, nitrogen, and oxygen.

It is proposed a liner arrangement for fitting a tubular insulator body in a circuit breaker. The liner arrangement includes a planar, electric-arc resistant and heat resistant liner layer comprising a first edge portion and a second edge portion that is located opposite the first edge portion, wherein the first edge portion has a first contour extending in a direction transversally to a plane defined by the planar liner layer. The second edge portion has a second contour having a geometry that is complementary to the first contour such that the first edge portion can be attached by way of a form fit to the second edge portion once the planar liner layer is bent to a tubular shape. Further, a circuit breaker including a liner arrangement and an insulator is described. A method for protecting an insulator body of a heat chamber insulator for a circuit breaker is also described.

The invention concerns a double-motion circuit breaker comprising primary and secondary movable contacts slidingly mounted within primary and secondary holders, wherein the primary movable contact comprises a tulip and a contact cylinder attached thereto, and the secondary movable contact comprises a pin for engaging the tulip but no counter-contact for engaging the contact cylinder. The circuit breaker also has a non-linear linkage mechanism with a pin and slot mechanism, and a fixed dielectric shield provided on the secondary holder. During disconnection, the linkage mechanism is preferably arranged to move the pin more than the tulip, proportionally to their maximum stroke, so as to quickly bring the pin tip within the fixed dielectric shield, whereafter the tulip moves more than the pin. This circuit breaker is cheaper, lighter and can be disconnected more quickly.