Patent ID: 7419558

Claim:
A method for manufacturing a self-closing tubular belt with predetermined compression forces at a longitudinal joint, comprising: providing a cylindrical small mandrel having a spiral rib, spirals of the spiral rib having spacers; winding a plastic material onto the small mandrel having a spiral rib, such that the plastic material thickness is not more than the height of the spiral rib; curing the plastic material; removing the plastic material from the small mandrel, resulting in the plastic material being in a form of a spiral rubber spring having gaps between its twists; winding the rubber spring on a larger mandrel such that widest sections of the spring are associated with one end of the mandrel diameter, and narrowest sections of the spring are associated with an opposite end of the mandrel diameter, thereby forming winding gaps; filling the winding gaps with a raw filler material; processing the rubber spring and the raw material so that all turns of the rubber spring are joined together monolithically; and removing the processed rubber spring with filler from the mandrel by making a longitudinal split in the spring, thereby producing the tubular belt having prestressed regions formed by the spring, and resisting portions formed by the filler material.