Ejection seat catapult

Claim 1

IN AN AIRPLANE WITH AN EJECTABLE SEAT FOR AN AIRMAN THEREIN, SAID AIRPLANE HAVING A CANOPY OVER THE SEAT, A SYSTEM FOR EJECTING THE SEAT FROM THE AIRPLANE IN COOPERATIVE COMBINATION WITH A SYSTEM FOR RAISING THE SEAT TO THE LEVEL OF THE CANOPY, SAID SYSTEM FOR EJECTING COMPRISING (A) AN OUTSIDE CONTAINER HAVING AN OPENING AT ITS TOP, THE BOTTOM OF SAID CONTAINER BEING ATTACHED TO THE AIRPLANE, (B) A TUBULAR CONTAINER WITHIN SAID OUTSIDE CONTAINER CONTAINING A PROPULSIVE CHARGE, SAID INNER CONTAINER BEING AXIALLY SLIDABLY MOVABLE IN SAID OUTSIDE CONTAINER AND SAID INNER CONTAINER PROJECTING FROM THE TOP OF SAID OUTSIDE CONTAINER THROUGH SAID OPENING AND BEING ATTACHED TO THE SEAT, (C) AN ENCLOSED SPACE BETWEEN THE BOTTOM OF SAID INNER TUBULAR CONTAINER AND A PROPULSIVE CHARGE THEREBELOW, AND (D) CONTROLLABLE MEANS FOR APPLYING GAS PRESSURE IN SAID SPACE AND CONNECTED THERETO THEREBY TO CONTROLLABLY MOVE SAID INNER TUBULAR CONTAINER UPWARD A PREDETERMINED AMOUNT TO RAISE SAID SEAT TO THE LEVEL OF THE SILL OF SAID CANOPY WITHOUT FIRING ANY OF SAID PROPULSIVE CHARGES.