METHOD OF BENDING MULTIELBOW THREE-DIMENSIONAL TUBES IN TUBE BENDING WINDING- TYPE MACHINES Russian patent published in 1997 - IPC

FIELD: plastic metal working, particularly tube bending in different industry branches for making bent multielbow three-dimensional pipelines. SUBSTANCE: method of bending multielbow three-dimensional tubes in winding-type tube bending machines comprises steps of placing and fixing tubular blank onto shaping member of bending head, deforming tubular blank by bending it, releasing tubular blank, measuring deformed state parameter in zone of rectilinear portion of blank subjected to further bending, rotating tubular blank before fixing it in order to perform each subsequent bending step in direction opposite relative to direction of twisting by gravity preliminarily bent portions. Blank is rotated by measured angle of twisting, the tubular blank is fixed on shaping member of bending head, its rectilinear portion is turned before subsequent bending of it in order to eliminate twisting to initial position. EFFECT: enhanced efficiency of method. 1 dwg