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US 4,770,735 AGranted
Techniques for welding thermoplastic tubes
AssigneeDenco, Inc.
InventorsJohn B. Shaposka, Dudley W. C. Spencer
Life of this patent
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AssigneeDenco, Inc.
InventorsJohn B. Shaposka, Dudley W. C. Spencer
Estimating the term…
Thermoplastic tubes are welded together in a dry condition with the tubes being open and maintained in their undistorted condition during the welding step. In an alternative technique a branch tube is welded to a main tube by placing the tubes in a non-parallel orientation in a holding device. A wafer cuts completely through one tube to form two tube sections. The wafer also cuts a notch from the other tube. One of the tube sections is shifted to become aligned with the notched other tube and welded thereto. A further technique includes placing at least one tube in a holding device which has a false floor for pressing against an area of the tube while the tube is being flattened at two spaced locations on opposite sides of the area. When the false floor is moved away from the tube a partial vacuum results. An air pocket is formed when the tube is severed by a wafer by air flowing into the cut tube.
A device for forming a branch connection of a thermoplastic tube to the side wall of a second thermoplastic tube comprising a holding device, said holding device comprising a first pair of clamping units for clamping a first tube extending across said clamping units, said clamping units being spaced from each other to provide an unobstructed path therebetween, a second pair of clamping units for clamping a second tube in an orientation non-parallel to the first tube, said second pair of clamping units being spaced from each other and having an unobstructed path in line with and communicating with said unobstructed path of said first pair of clamping units whereby the second tube may extend across said unobstructed path, cutting means relatively movable in said unobstructed path for cutting through the first tube to create a pair of tube sections and for cutting a notch from the second tube, one of said first pair of clamping units and one of said second pair of clamping units on the same side of said unobstructed path being shiftably mounted to realign the cut tubes for aligning one of the tube sections with the second tube at the location of the cut notch, means for heating the notch of the realigned second tube and the cut end of the tube section realigned with the notch, and means for pressing the heated realigned cut tubes to weld the cut tubes together whereby the welded tube section forms a branch to the second tube.
A method for forming a branch connection from a first thermoplastic tube to the side wall of a second thermoplastic tube comprising mounting the first tube across a gap between a first pair clamping units, mounting a second tube in a second pair of spaced clamping units with a spacing between the second pair of clamping units being in line with the gap and forming a continuous unobstructed path and with the second tube being in an orientation non-parallel to the first tube and with the second tube extending across the unobstructed path, moving a cutting device through the unobstructed path to cut the first tube into a pair of cut sections and to cut a notch from the second tube, realigning the tubes to align one of the cut sections with the notched second tube, heating the notch of the realigned second tube and the cut end of the tube section realigned with the notch, and pressing the heated realigned tubes to weld the cut section to the notched second tube whereby the cut section forms a branch of the second tube.
Dependencies are inferred from the claim text.