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US 3,943,334 AGranted
Heat weldable, thermoplastic fitting
AssigneeVon Roll AG
InventorWerner Sturm
Life of this patent
Estimating the term…
Abstract
To permit efficient heat welding of pipe fittings, and the like, of thermpolastic material to thermoplastic pipes, by electrically heating of the fitting, the fitting is made in two concentric portions, the inner portion having a heating wire applied to the outside thereof, the heating wire and inner portion being covered by the outer portion, for example injected thereover.
Claims10
Unitary heat-weldable thermo-plastic fitting for assembly over heat weldable pipe comprising
- an inner part (1) of tubular, thermoplastic material and having an inner diameter corresponding to the outer diamerter of the pipe,
- a heating wire (5) spirally wound about the outer circumference of the inner part and electrically accessible externally of the fitting;
- an outer part (16) of tubular, thermoplastic material surrounding the inner part and covering the spiral winding (5);
- the inner part (1) being arranged in two axially separated end portions (2, 3) adjacent the ends of the fitting and a central portion (14) connecting the end portions (2, 3);
- the outer circumference of the end portions (2, 3) of the inner part (1) being formed with spirally arranged grooves (4);
- and wherein the wire (5) is located in said grooves (4) and includes a connecting segment (15) connecting the wire in the grooves of said axially separated end portions (2, 3) and passing across the central portion (14).
3 more elements
Dependencies are inferred from the claim text.