A corrugator for molding externally ribbed and corrugated thermoplastic pipes, including two trains of moldblock halves circulating respectively in two endless paths and cooperating with each other to form a travelling mold for the thermoplastic pipes. The halves of one train are biased in relation to...http://www.google.es/patents/US4789322?utm_source=gb-gplus-sharePatente US4789322 - Corrugator with intermeshing overlapping moldblock halves
Corrugator with intermeshing overlapping moldblock halves
