Patent ID: 6142005
Filing Date: 2000-11-07
Classification: B21D

Abstract:
A die-protecting device used in bending an embossed metallic straight pipe with a small diameter and a thin wall into a bent embossed pipe on a bending machine, being comprised of a die core, a pair of half-dies, a flexible plastic pipe, a spiral spring, a tension spring and two sealing covers, said die core is made by placing a plastic bag in a hole of said embossed pipe, loading therein with mercury and then sealing the mouth of said plastic bag, said device is characterized by:said pair of half-dies are made by mould forming with polyurethane or rubber and are provided with die cavities having the contour of the external wall surface of said embossed pipe;said straight embossed pipe is placed in said pair of half-dies, said flexible plastic pipe is slipped over said half-dies, then said spiral spring is slipped over said plastic pipe, and further said tension spring is slipped over said spiral spring, the two open ends of said tension spring have annuli provided with external threads and welded thereto for mounting said sealing covers, thereby said die-protecting device is adapted for supporting and bending said embossed metallic straight pipe on said bending machine.