Method of producing a reinforced endless toothed belt of synthetic

Abstract

A method of producing an endless reinforced toothed belt of synthetic plastics material, the circumferential length of which in the untensioned condition has a predetermined minus tolerance in relation to an operationally tensioned intended circumference having the exact tooth pitch. The steps include placing on a molding wheel and a tensioning wheel a helically wound wire coil with fixed wire ends, the molding wheel and the tensioning wheel having an interaxial distance at which the wire coil has the minus tolerance in relation to the intended circumference. Then the wound wire coil is tensioned with elastic stretching of the wire turns and is enlarged to the intended circumference by increasing the interaxial distance to the intended distance. Then, with the molding wheel and the molding belt, a closed mold cavity is formed, and by injection of synthetic plastics material into the mold cavity beginning, a synthetic plastics strand of toothed-belt shape is produced in which the wire coil is embedded in the mold cavity. With one revolution of the wire coil, the synthetic plastics strand issuing from the mold cavity end is conducted back around the tensioning wheel into the mold cavity beginning, and in the mold cavity the beginning of the synthetic plastics strand is fused with its end.