Electrical arc quenching chamber, in particular for fluid-quenched circuit breakers

An electric arc interruption chamber particularly adapted for use with fluid-quenched circuit breakers having an arc-quenching gas within a sealed electrically insulated casing comprising a movable main contact and a stationary main contact each having a respective arc contact, said movable arc contact being a tulip contact defined by a plurality of spaced fingers, a generally bell-shaped member constructed of electrically insulated material, said bell-shaped member being defined by a peripheral wall and an end wall, said end wall having an opening in alignment with and through which relatively moves said stationary arc contact, an exterior of said fingers and an interior of said bell-shaped member defining a first chamber, said movable main contact having a housing constructed of electrically insulating material;

• said housing being defined by a peripheral wall and an end wall in external space relationship to said bell-shaped member peripheral wall and end wall, respectively, and defining therewith a second chamber;
• said housing end wall having an opening in alignment with and through which relatively moves said stationary arc contact;
• means cooperatively defined by an exterior of said bell-shaped member and an interior of said housing for forming arc-quenching gas flow zones in said second chamber for directing arc-quenching gas along said second chamber toward said opening, into said first chamber and into said tulip contact;
• and said arc-quenching gas flow zones include both low speed/low pressure zones and high speed/high pressure zones.