3 596 028 issued to kane et al and assigned to the assignee of the instant application with attention being directed to fig4 it will be observed that there is provided a separable contact structure 7 having a moving contact 9 which is attached at its upper end as at 9a to the lower threaded end 11a of an upper operating rod 11 the latter projecting upwardly into a dome portion 13 of the arc extinguishing assemblage 3 fig1 wherein a suitable high voltage operating mechanism 15 such as a piston and cylinder arrangement may be provided to effect upward opening motion of the movable contact 9 or downward closing motion of the same reference may be made to u s pat no 3 590 189 issued june 29 1971 to fischer et al for a detailed description of the high voltage operator 15 which is disposed interiorly within the upper dome portion 13 of the extinguishing assemblage 3 also if desired reference may be made to u s pat no 3 596 028 issued to kane and reese and assigned to the assignee of the instant application for a detailed description of the operation of the circuit interrupter 1 and the method of controlling gas flow during extinction of the arc not shown established between the moving main contact 9 and the stationary main contact structure 17 of fig4 of the drawings in order to understand the present invention however it is only necessary to know that high pressure gas 19 for example sulfur hexafluoride sf 6 gas say at 260 p s i exists in the region 21 exteriorly of the separable main contact.