Self-extinguishing switch

A gas blast type circuit interrupter, comprising:

• a hollow cylindrical member adapted to be disposed within a space having an arc-extinguishing gas therein, said member having a first end and a second end, said second end having a central opening therein;
• a hollow cylindrical member adapted to be disposed within a space having an arc-extinguishing gas therein, said member having a first end and a second end, said second end having a central opening therein;
• a cylindrical piston slidably disposed within said hollow cylindrical member for translational movement along the axis of said hollow cylindrical member between a first extreme position toward said first end and a second extreme position toward said second end, said second extreme position being at a predetermined distance from said second end, said piston and said second end thereby defining a variable volume chamber within said hollow cylindrical member, said chamber being in gas communication with said space and accommodating a portion of said arc-extinguishing gas;
• stop means disposed on the inside surface of said hollow cylindrical member for stopping said piston at said predetermined distance from said second end;
• a first contact member fixedly disposed in said cylindrical member, said cylindrical piston being movable independently of said first contact member;
• a second contact member disposed in said housing for translational movement along the axis of said hollow cylindrical member between a first extreme location in said variable chamber and a second extreme location outside said chamber, said second contact member in said first extreme location engaging with said first contact member for forming an electrical circuit therewith and engaging said piston for holding said piston in said first extreme position, and said second contact member extending out of said chamber through said opening in said second end, and said second member having said one end disengaged from said first contact member and said piston in said second extreme location;
• said second contact member being movable from said first location to said second location for interrupting a circuit and thereby striking an electric arc across said contact members;
• and
• piston moving means responsive to the movement of said second contact from said first to said second locations for moving said piston from said first to said second position, whereby said portion of arc-extinguishing gas compressed by the movement of the piston and the temperature of which is raised by said arc is blown at the arc through said opening when said one end of said second contact member is moved outside of said chamber.