Abstract: A method for manufacturing a self-closing tubular belt with predetermined compression forces at a longitudinal joint comprises winding a plastic material onto a small mandrel such that the plastic material thickness is not more than the height of a mandrel spiral rib, curing the plastic material, and 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. The resultant rubber spring is then wound on a larger mandrel thereby forming winding gaps. These winding gaps are then filled with a raw filler material, and these are processed so that all turns of the rubber spring are joined together monolithically. This is removed from the mandrel by making a longitudinal split in the spring, producing the tubular belt having prestressed regions formed by the spring, and resisting portions formed by the filler material.

Abstract: A prestressed tubular belt has variable prestressing forces located along its width to provide control overt the shape of the belt, while at the same time providing the proper forces in order to maintain the integrity of the belt shape. Various methods and systems are utilized in the manufacturing of such a tubular belt. One such methods involves stretching and affixing one portion of a belt layer to a non-stretched layer in a stepwise manner. Another system and appertaining method involves utilizing anchor strips affixed to a layer of the belt and then stretching the belt in a stepwise manner using ribs on a tool that mate with the anchor strips to hold the layer in varying degrees of tension prior to affixing a second layer to it. Other mechanisms for applying variable prestressing forces are also considered.

Abstract: A prestressed tubular belt has variable prestressing forces located along its width to provide control over the shape of the belt, while at the same time providing the proper forces in order to maintain the integrity of the belt shape. Various methods and systems are utilized in the manufacturing of such a tubular belt. One such method involves stretching and affixing one portion of a belt layer to a non-stretched layer in a stepwise manner. Another system and appertaining method involves utilizing anchor strips affixed to a layer of the belt and then stretching the belt in a stepwise manner using ribs on a tool that mate with the anchor strips to hold the layer in varying degrees of tension prior to affixing a second layer to it. Other mechanisms for applying variable prestressing forces are also considered.