Visible break switch

A viewing assembly for use with a gas filled, pressurized and hermetically sealed switch housing comprising:

• a mounting ring adapted to be welded around an aperture provided on the housing, wherein said mounting ring is formed with an inwardly facing annular groove;
• a first gasket which is received in said annular groove;
• a viewing window having one side sealed against said first gasket;
• a second gasket that seats against the other side of said viewing window;
• a slip ring that seats against said second gasket;
• and
• a window ring clamp that seats against the slip ring and fastens the entire assembly together.

A puffer interrupter switch comprising:

• a hermetically sealed housing filled with dielectric gas under pressure;
• a plurality of pairs of feedthrough bushings hermetically sealed to said housing, each of said bushings having an electrical terminal extending externally of said housing for connection to an external electric circuit and an electrical terminal disposed within said housing;
• a plurality of puffer interrupter assemblies disposed within said housing and aligned along a linear axis, each of said assemblies having a pair of interrupting contacts disposed within a transparent tube, said interrupting contacts being electrically coupled to said electrical terminals disposed within said housing;
• means for moving said interrupting contacts into and out of contact;
• and
• means for viewing at least one of said interrupting contacts from outside said housing.

A method of determining the position of a pair of interrupting contacts disposed within a pressurized metal housing of a switch from outside of said housing comprising the steps of:

• hermetically sealing said housing;
• pressurizing said housing with a dielectric gas;
• and
• providing at least one puffer interrupting assembly within the housing including a pair of interrupting contacts disposed within a transparent tube.