Process and apparatus for manufacturing elongated glass products

Claim 1

IN A PROCESS FOR MANUFCTURING GLASS TUBING IN A FEED ZONE HAVING STATIONARY PLATINUM WALLS AND IN AN ADJACENT TUBE-FORMING ZONE HAVING TWO STATIONARY PLATINUN WALLS, ONE INSIDETHE OTHER, TODEFINE A VOID THEREBETWEEN OF THE DESIRED TUBING CONFIGURTION, THE STEPS COMPRISING PASSING MOLTEN GLASS FIRST INTO THE FEED ZONE AND THERE FROM SAID FEED ZONE INTO SAID TUBE-FORMING ZONE TO FILL THE VOID BETWEEN SAID PLATINUM WALLS OF THE TUBE-FORMING ZONE AND FORM GLASS TUBING AT THE TRAILING EDGE OF SAID WALLS, PROVIDING SAID FEED ZONE WITH A CROSS-SECTION SMALLER THAN THE CROSS-SECTION OF SAID TUBE-FORMING ZONE TO ACHIEVE CONTROL OVER THE FLOW OF GLASS PASSING THROUGH SAID TUBE-FORMING ZONE, FLOWING STREAM OF AMBIENT AIR THROUGH THE INTERIOR OF SAID TUBE-FORMING ZONE SO THAT THE INNER PLATINUM WALL THEREOF AND THE INNER SURFACE OF THE GLASS TUBING FORMED AT THE TRAILING EDGE OF SAID INNER WALL AREEXPOSED TO THE AMBIENT ATMOSPHERE TO EQUALIZE COOLING OF THE GLASS TUBING BEING FORMED AND PREVENT DISTORTION THEREOF, AND HEATING THE EXTERIOR WALLS OF SAID FEED ZONE AND SAID TUBE-FORMING ZONE TO FURTHER CONTROL THE RATE OF FLOW OF THE GLASS MATERIAL THROUGH THE VOID BETWEEN THE WALLS OF SAID TUBE-FORMING ZONE.