Method including the preventing of bulging of the walls enclosing a space during themolding insitu of foamable plastic materials

Claim 1

THE METHOD OF FILLING WITH A FOAM A STRUCTURE HAVING SPACED FLEXIBLE BUT NON-EXTENDIBLE, SUBSTANTIALLY IMPERVIOUS SHEET WALLS, PROVIDING A SPACE THEREBETWEEN, AND CAPABLE OF BULGING OUTWARDLY WHEN A PRESSURE IS EXERTED ON THEIR INTERIOR SURFACES, COMPRISING: (A) PLACING SAID STRUCTURE WITHIN A SUBSTANTIALLY FLUIDTIGHT CHAMBER, IN WHICH A FLUID, WHEN INTRODUCED INTO SAID CHAMBER CONTACTS THE OUTER SURFACE OF EACH OF SAID WALLS, (B) INSERTING INTO SAID SPACE, FOAM-FORMING MATERIAL, (C) FORMING WITHIN SAID SPACE A FOAM WHICH, DURING ITS FORMATION EXPANDS AND EXERTS A VARYING OUTWARD PRESSURE ON SAID WALLS, HAVING A TENDENCY TO CAUSE BULGING OUTWARDLY OF SAID WALLS, (D) DURING THE FORMATION OF THE FOAM, CONTACTING THE EXTERIOR SURFACE OF EACH OF SAID SPACED WALLS WITH A FLUID WHICH HAS BEEN INTRODUCED INTO SAID FLUIDTIGHT CHAMBER PRIIOR TO THE FORMATION OF SAID FOAM, AND (E) VARYING THE PRESSURE OF SAID FLUID TO EXERT ON THE EXTERIOR OF EACH OF SAID WALLS AN INWARDLY DIRECTED PRESSURE SUBSTANTIALLY EQUAL AND OPPOSITE TO THAT OUTWARD EXPANSION PRESSURE EXERTED BY SAID FOAM DURING ITS FORMATION, THEREBY PREVENTING BULGING OF SAID WALLS.

Claim 2

THE METHOD OF FILLING WITH A FOAM A STRUCTURE HAVING SPACED FLEXIBLE BUT NON-EXTENDIBLE, SUBSTANTIALLY IMPERVIOUS SHEET WALLS, PROVIDING A SPACE THEREBETWEEN, AND CAPABLE OF BULGING OUTWARDLY WHEN A PRESSURE IS EXERTED ON THEIR INTERIOR SURFACES, COMPRISING: (A) PLACING SAID STRUCTURE WITHIN A SUBSTANTIALLY FLUIDTIGHT CHAMBER, IN WHICH A FLUID, WHEN INTRODUCED INTO SAID CHAMBER CONTACTS THE OUTER SURFACE OF EACH OF SAID WALLS, (B) INSERTING INTO SAID SPACE, FOAM-FORMING MATERIAL, (C) FORMING WITHIN SAID SPACE A FOAM WHICH, DURING ITS FORMATION EXPANDS AND EXERTS A VARYING OUTWARD PRESSURE ON SAID WALLS, HAVING A TENDENCY TO CAUSE BULGING OUTWARDLY OF SAID WALLS, (D) DURING THE FORMATION OF THE FOAM, CONTACTING THE EXTERIOR SURFACE OF EACH OF SAID SPACED WALLS WITH A FLUID WHICH HAS BEEN INTRODUCED INTO SAID FLUIDTIGHT CHAMBER PRIIOR TO THE FORMATION OF SAID FOAM, AND (E) VARYING THE PRESSURE OF SAID FLUID TO EXERT ON THE EXTERIOR OF EACH OF SAID WALLS AN INWARDLY DIRECTED PRESSURE SUBSTANTIALLY EQUAL AND OPPOSITE TO THAT OUTWARD EXPANSION PRESSURE EXERTED BY SAID FOAM DURING ITS FORMATION, THEREBY PREVENTING BULGING OF SAID WALLS.