Method of form removal from precision casting shells

Claim 1

THE PROCESS OF PRODUCING A MOLDING SHELL FOR THE CASTING OF SHAPES THEREIN COMPRISING THE STEPS OF PREPARING A HOLLOW SHAPED PATTERN SUPPORT, EMBEDDING TO SAID PATTERN SUPPORT A PATTERN FORMED OF A SOLUBLE SYNTHETIC RESIN, FORMING A REFRACTOR SHELL MOLD AROUND SAID PATTERN, REMOVING SAID PATTERN SUPPORT FROM SAID MOLD TO EXPOSE A PORTION OF SAID PATTERN, THEREAFTER APPLYING A LIQUID RESIN SOLVENT TO AT LEAST SAID EXPOSED PATTERN PORTION UNTIL SAID PATTERN IS AT LEAST PARTIALLY DISSOLVED AND IS SOFTENED TO A CONDITION WHEREIN THE SOFTENED PATTERN HAS A LOW DEGREE OF EXPANSION FORCE UNDER HEAT OF INTENSITY NECESSARY TO VOLATILIZE THE PATTERN, SAID SLVENT BEING APPLIED WHILE MAINTAINING SAID PATTERN AT A TEMPERATURE BELOW THAT WHICH WOULD CAUSE SAID PATTERN TO EXPAND AND CRACK SAID MOLD, AND THEN HEATIN SAID MOLD ABOVE THE HET VOLATILIZATION TEMPERATURE OF SAID PATTERN TO REMOVE ANY REMAINING PATTERN MATERIAL FROM SAID MOLD.