Abstract: A medium voltage circuit breaker and switch having first and second stationary contacts, a mobile conducting bridge equipped with first and second movable contacts, an operating mechanism coupled to said bridge. The switch further having a vacuum cartridge containing a third stationary contacts electrically connected to the second stationary contacts, a third movable contact electrically connected to said bridge, and mechanically coupled to said operating mechanism, and sequencing means designed to establish the opening and closing sequences of the first, second, and third contacts cooperating with the operating means so that in the course of opening or closing operations of the switch, the third stationary and movable contacts close momentarily to switch the arc associated with the first stationary and movable contacts or with the second stationary and movable contacts.

Abstract: A vacuum cartridge for a medium voltage electrical switch, as well as a switch incorporating such a cartridge comprising an enclosure closed by two end-plates in which there are housed three contacts extending axially. Two of these contacts are stationary and comprise a disk-shaped contact part and are securely fixed respectively to the two end-plates, whereas the third contact is formed by a rod slidably mounted in the second stationary contact, the rod being brought into contact with the first stationary contact during a period sufficient to generate an electrical arc between the two stationary contacts in order to perform breaking of an electrical circuit. A switch comprises an enclosure filled with sulphur hexafluoride including a cartridge as previously described, two main contacts electrically connected in parallel to the stationary contacts and an operating mechanism connected to selected aformentioned contacts.

Abstract: In the process of fixing a metal screen in the housing of a vacuum switch, the screen is plastically deformed radially outwards over an internal supporting edge in the housing. The plastic deformation of the screen is carried out at an edge thereof, in such a way that an outward flanged edge is formed. Thus, the screen is retained on the supporting edge by that flanged edge and a part of the housing with a relatively large diameter. Therefore, the screen has a part with a relatively small diameter which is essentially equal to the internal diameter of the supporting edge of the housing.