Pressurized isolating envelope for e.g. circuit breaker, has insert creating weak area such that insert is driven to liberate passage during increase of pressure in presence of defect within envelope so as to permit release of plasma

摘要

The envelope (E) has a fragility zone to create a passage through a wall (3) of the envelope permitting to release plasma generated during internal defect. The fragility zone is formed through an elastomeric insert (1) molded within a housing (21) provided in the wall of the envelope. The insert creates a mechanically weak area inside the wall such that the insert is driven to liberate the passage during increase of pressure in the presence of the internal defect within the envelope so as to permit release of the plasma.