Arc self-extinguishing switch device

An arc self-extinguishing switch device comprising:

• a housing having an interior filled with an arc extinguishing fluid;
• an envelope disposed within said interior of said housing, said envelope having therein at least one pressure increasing compartment filled with said arc extinguishing fluid;
• first contact member means positioned within said compartment;
• second contact member means, movable from a closed first position in contact with said first contact member means toward an open second position spaced from said first contact member means, for, upon movement of said second contact member means away from said first contact member means, establishing an electric arc between said first and second contact member means, whereby said electric arc increases the pressure of said arc extinguishing fluid in said compartment;
• said envelope having extending through a side thereof, from said compartment to said interior of said housing, opening means for discharging said increased pressure arc extinguishing fluid from said compartment to said interior of said housing in a direction substantially transverse to and crossing the axis of said electric arc;
• said opening means comprising a straight slit having a depth in said direction and a width transverse to said direction and to said axis of said electric arc, said depth being substantially greater than said width, such that said slit is elongated in said direction;
• and
• said second contact member means, when in said closed first position thereof, extending through said slit and closing said slit, said second contact member means having a flat cross-section elongated in said direction, and said movement of said second contact member means away from said first contact member means opening said slit.