Method for making a plastic drip chamber

Claim 1

A MOLD FOR MAKING A DRIP CHAMBER FROM THERMOPLASTIC TUBING COMPRISING A MOLD BODY HAVING A CYLINDRICAL CAVITY OF INSULATING MATERIAL WITH AN UPSTANDING METAL SPINDLE AT ITS CENTER FORMING AN ANNULAR RECESS BETWEEN IT AND THE CAVITY FOR RECEIVING THE LOWER END OF A LENGTH OF TRANSPARENT THERMOPLASTIC TUBING, SAID SPINDLE HAVING A DOME SHAPED UPPER END EXTENDING ABOVE SAID ANNULAR RECESS AND OPPOSITE THE UPPER END OF SAID LENGTH OF TUBING, A SMALL DIAMETER METAL SPINDLE PROJECTING UP FROM THE CENTER OF SAID DOME SHAPED UPPER END FOR RECEIVING A LENGTH OF SMALLER DIAMETER THERMOPLASTIC TUBING, SAID DOME SHAPED SECTION HAVING A REENTRANT ANNULAR RECESS FOR RECEIVING THE LOWER END OF THE SMALLER DIAMETER TUBING A CONTROLLED DISTANCE BELOW THE OUTER SURFACE OF SAID DOME SECTION, A METAL MOLD CAP HAVING ACAVITY COMPLEMENTARY TO AND OF SLIGHTLY LARGER SIZE THAN SAID DOME SECTION AND HAVING A CENTRAL OPENING SLIDABLY RECEIVING THE UPPER END OF SAID SMALL DIAMETER TUBING, INSULATING MEANS BETWEEN SAID MOLD CAP AND BODY, A SOURCE OF HIGH FRE-