Apparatus for shrinking tubular glass blank

Claim 1

APPARATUS FOR USE IN FORMING A TUBULAR GLASS ARTICLE OF RELATIVELY SMALLER BORE FROM A TUBULAR GLASS BLANK OF RELATIVELY LARGER BORE BY SHRINKING IT AROUND A MANDREL WHICH COMPRISES A FIRST SUPPORTING ASSEMBLY FOR SUPPORTING A FIRST END OF A TUBULAR GLASS BLANK, A SECOND SUPPORTING ASSEMBLY FOR SUPPORTING A SECOND END OF A TUBULAR GLASS BLANK, A TUBULAR MANDREL EXTENDING BETWEEN THE FIRST AND SECOND SUPPORTING ASSEMBLIES, MEANS FOR PROVIDING COMMUNICATION BETWEEN THE ATMOSPHERE AND THE SPACE BETWEEN THE MANDREL AND A GLASS BLANK ASSEMBLED THEREAROUND AT THE SAID FIRST END THEREOF, A SOURCE OF HEAT FOR SOFTENING THE GLASS IN A TUBULAR BLANK SUPPORTED BETWEEN THE SUPPORTING ASSEMBLIES AND MOUNTED FOR MOVEMENT BETWEEN THE TWO SUPPORTING ASSEMBLIES, AND MEANS FOR INTRODUCING A COOLING FLUID THROUGH THE END OF THE MANDREL ADJACENT THE FIRST SUPPORTING ASSEMBLY, SAID MANDREL HAVING AN OPEN DISCHARGE END ADJACENT THE SECOND SUPPORTING ASSEMBLY AND SAID SECOND SUPPORTING ASSEMBLY HAVING A PASSAGEWAY EXTENDING LONGITUDINALLY THERETHROUGH SURROUNDING AND EXTENDING BEYOND THE DISCHARGE END OF THE MANDREL FORMING AN ASPIRATING CHAMBER SO THAT FLUID DISCHARGING FROM SAID MANDREL PRODUCES AN ASPIRATING EFFECT TO CAUSE AIR TO BE SUCKED THROUGH SAID PASSAGEWAY FROM THE SPACE BETWEEN THE MANDREL AND A TUBULAR GLASS BLANK SUPPORTED BY THE SUPPORTING ASSEMBLIES.