Abstract: A switch disconnector apparatus of the linear air type is described, said apparatus comprising: an upper device for transferring current, a fixed upper contact connected electrically to the upper device, a lower device for transferring current, a sliding lower contact connected electrically to the lower device and a contact tube movable between a closing position and a disconnecting position. According to the invention, the apparatus also comprises a casing of insulating material which forms a protective atmosphere. Moreover, the contact tube, the upper contact and the lower contact are substantially completely enclosed inside the casing. The disconnector is therefore closed, inside a protected environment, segregated, but not perfectly sealed. With the present invention all the drawbacks associated with unprotected air systems are avoided and a compact and safe apparatus preventing discharges between several phases is provided.

Abstract: An electric device, in particular for medium or high voltage electric substations, able to perform the functions of circuit-breaking, isolating and earthing is described. The device comprises: a casing; at least one circuit-breaker; at least one line isolator having a fixed isolator contact; a line isolator actuating shaft for actuating the at least one line isolator; at least one earthing isolator; a circuit-breaker actuating shaft for actuating at least one circuit-breaker; and a lever connected to a conductor rod co-operating with movable circuit-breaker contacts, said conductor rod further engaging with said fixed isolator contact in a closing position, wherein: the device further comprises a resilient member co-operating with said conductor rod in order to transfer correct pressing loads to said movable contacts. According to the invention, said circuit-breaker actuating shaft and said line isolator actuating shaft are coaxial. Profitably, the casing is filled with nitrogen or sulphur hexafluoride.

Abstract: A switch disconnector apparatus of the linear air type is described, said apparatus comprising: an upper device for transferring current, a fixed upper contact connected electrically to the upper device, a lower device for transferring current, a sliding lower contact connected electrically to the lower device and a contact tube movable between a closing position and a disconnecting position. According to the invention, the apparatus also comprises a casing of insulating material which forms a protective atmosphere. Moreover, the contact tube, the upper contact and the lower contact are substantially completely enclosed inside the casing. The disconnector is therefore closed, inside a protected environment, segregated, but not perfectly sealed. With the present invention all the drawbacks associated with unprotected air systems are avoided and a compact and safe apparatus preventing discharges between several phases is provided.