Patent ID: 6715334
Filing Date: 2004-04-06
Classification: B21D

Abstract:
An apparatus for manufacturing a thick-walled bent pipe comprising:a presser die; a lower die movably attached to a stationary portion of said apparatus, said lower die including a pair of bottom dies having means for meshing with means to be meshed which is secured to said stationary portion of said apparatus and biasing means for pressing the pair of bottom dies upward by a resilient force such as a spring force or the like; wherein, at the time of formation, the pair of said bottom dies are caused to rotate opposite to each other about a single center point from an initial position as said means for meshing meshes with the means to be meshed, with a descent of said presser die to perform the formation and, after the formation is finished, the pair of bottom dies are pressed upward by the biasing means and caused to rotate opposite to each other about the single center point as said means for meshing meshes with the means to be meshed, with an ascent of said pressure die, to thereby return to the initial position.