Device for guiding band like materials having at least a cylinder-core and several lamella rings mounted thereon, and a procedure to produce said device

A sectional ring (2), especially suited as a rotary tensioning roller, has at least one intentional reflex bend (4, 14). Two such bends may be included; hence seen in cross section, the roller section is approximately Z-shaped. The bridging section has a pair of parallel edges enclosing an angle with the axis, or it may become thicker towards the axis. As construction materials, rubber, natural rubber, plastic or similar are suitable. The key feature is that when radial pressure is exerted onto the ring, the outer cylindrical surface (20) shifts its position along the axis, but maintains parallelism with that axis. In addition to the sectional ring, a stretching-roller formed with its aid, and the procedure to manufacture a complete, smooth-surfaced roller are also claimed.