Casting propellant charges

Claim 1

A PROCESS OF MAKING A DOUBLE BASE PROPELLENT GRAIN WHICH COMPRISES THE STEPS OF DELIVERING A DESIRED QUANTITY OF CASTING POWDER CONTAINING NITROCELLULOSE TO A TUBULAR CONTAINER, THE INSIDE OF WHICH DEFINES THE OUTSIDE SHAPE OF THE GRAIN, PLACING SAID CONTAINER IN A CLOSED CHAMBER, REDUCING THE PRESSURE IN THE CHAMBER BELOW ATMOSPHERIC PRESSURE, THE PRESSURE INSIDE THE CHAMBER BEING SUBSTANTIALLY THE SAME AS OUTSIDE OF THE CONTAINER TO PREVENT ITS COLLAPSE, FLOWING A LIQUID CONTAINING A NITRIC ESTER AND A PLASTICIZER THROUGH THE POWDER UNDER THE INFLUENCE OF THE DIFFERENCE IN PRESSURE BETWEEN THE INSIDE OF THE CHAMBER AND THE ATMOSPHERE, AND AT A RATE TO COMPLETELY SATURATE THE POWDER BEFORE THE POWDER AND LIQUID COALESCE INTO A SOLID MASS, RESUMING ATMOSPHERIC PRESSURE ON THE MASS AFTER THE POWDER HAS BEEN COMPLETELY SATURATED AND PRIOR TO COALESCENCE OF SAME, THEREBY EFFECTING COLLAPSE OF OCCLUDED RAREFIED AIR POCKETS IN THE MASS TO NEGLIGIBLE VOLUME, AND THEREAFTER CURING THE GRAIN AT ELEVATED TEMPERATURE.