a corrugator device for shaping thermoplastic corrugated pipes out of a molten plastic tube issuing from an extrusion device may include moving molding jaws which circulate in a linear molding section and are arranged in paired successive relationship in the molding section forming a molding passage . the pairs of molding jaws may be formed from left - hand and right - hand molding jaws and between them enclose a cylindrical mold cavity to form the molding passage . the device may include a gripper device for guiding the molding jaws from the end of the molding section back to the start of the molding section , and having grippers respectively for the left - hand and the right - hand molding jaws , each with a separate guide and drive device .