Total containment welding or plastic tubes
AssigneeDenco, Inc.
InventorsJohn B. Shaposka, Dudley W. Spencer
Life of this patent
Estimating the term…
Abstract
Plastic tubes are welded by placing a pair of tubes in a pair of aligned holders with each tube folded toward itself. A wafer is movably mounted in the gap between the tubes and is heated to cause the ends of the tubes to melt without actually cutting through the tubes. The melted ends of opposed tubes can be pressed into contact with each other to form a welded connection. In a variation a pair of cutting blades cut the folded ends of the tubes and the cut ends are then melted by a wafer and subsequently pressed into contact with each other.
Claims31
A total containment welding system for plastic tubes comprising a pair of aligned tube holders for holding a pair of plastic tubes in line with each other, a wafer capable of being heated to an elevated temperature for melting the plastic tubes when the plastic tubes are in contact with or close to said wafer, said wafer being mounted on a wafer mounting unit for moving said wafer in the gap between the plastic tubes in a transverse direction perpendicular to the aligned plastic tubes, and means for urging said holders toward each other simultaneously with the movement of said wafer from at least the time the plastic tubes initially contact the wafer to maintain the plastic tubes in their proper contacting position with said wafer as said wafer moves through said gap to melt the ends of the plastic tubes and to urge the melted ends of the plastic tubes into contact with each other to weld the plastic tubes together.
A tube end removal unit for removing the ends of aligned and spaced plastic tubes to facilitate the butt welding of the plastic tubes comprising a heat conductive sheath, said sheath having a pair of spaced side walls terminating in leading edges, said leading edges comprising cutting blades for cutting through the plastic tubes, a heater located between said spaced side walls of said sheath, and a shield between said side walls mounted over said heater.
A method of welding a pair of hollow plastic tubes comprising mounting the tubes in alignment with each other in aligned tube holders which are spaced from each other with a gap being between the tube ends, heating a wafer, moving the wafer through the gap, simultaneously urging the ends of the tubes against the wafer throughout the movement of the wafer through the gap with the wafer being maintained in contact with and melting the ends of the tubes as the wafer is moving through the gap from at least the time the ends of the tubes initially contact the wafer to melt the ends of the tubes by the moving wafer and thereby expose their hollow interiors by a melt-wipe procedure, and pressing the melted ends of the aligned tubes into contact with each other after the wafer has passed through the gap to weld the aligned tubes together.
Dependencies are inferred from the claim text.