Abstract: An electrical switching apparatus is disclosed with a moveable insulating nozzle for blowing an arc. According to the invention, the insulating nozzle is connected in an interlocking and force-fitting manner to at least one moveable component part of the switching apparatus by means of a clamping device and without a screw connection. Exemplary embodiments relate, inter alia, to: a clamping hold of the insulating nozzle on the moving buffer cylinder and/or at the opposite end on a part to be moved, in particular a moveable shielding electrode or an auxiliary gear mechanism for a contact system, which is driven on both sides. Advantages include: simple fitting of the insulating nozzle, small physical volume of the clamping device; precise coaxial fixing of the insulating nozzle in relation to the switch axis.

Abstract: The switching chamber is intended for a gas-insulated high-voltage circuit breaker. It contains an axially symmetrical housing and a contact arrangement held in the housing with two switching pieces, of which at least one is arranged such that it can move along the housing axis. The switching chamber housing has two hollow bodies consisting of electrically conductive material which can be connected to a high voltage and an insulating tube holding the hollow bodies axially at a distance. A separation zone, which is electrically shielded during operation of the circuit breaker, is formed in the surface of at least one of the two hollow bodies and separates two surface zones having different degrees of roughness from one another in the hollow body. Inhomogeneities in the surface of the switching chamber housing which may reduce the dielectric strength of the circuit breaker equipped with the switching chamber therefore do not have any effect.

Abstract: The disclosure relates to an electrical contact system for a switching device having a mating contact and a second contact. According to the invention, the second contact has a contact tulip, at the outer face of which a current transfer takes place to an annular part of the mating contact. Exemplary embodiments relate to, inter alia: additional current transfer at an inner contact-making face of the contact tulip to a pin-shaped part of the mating contact; mating contact with mating contact tulip for engaging with the contact tulip; and measures for improving the contact forces. Advantages include: tulip-in-tulip design with large contact face, high contact force, reduced number of contact fingers, reduced number of mating contact fingers, and improved adjustment tolerance; contact tulip acts as an arcing contact and at the same time as a short-term current contact.