Device for bending tubes or profiled sections with symmetrical structure for two-way bending and machine equipped with same

Abstract

The invention relates to a bending head, for example, for a rotary draw bending technique, of the type including a bend form clamp assembly set in rotation about an axis and at least one roller keeping a tube or a profiled section clamped against the bend form during bending. The single assembly can be positioned in one or other of two bending starting positions that are symmetric with respect to the axis of the tube so as to allow either bending in one direction of bending starting from, or bending in an opposite direction starting from (P 2 ). The rectilinear movement of the clamp in two directions (ox) and (oy) and its optimal orientation relative to the roller are obtained using a system involving an eccentric.

1 . A bending head for a rotary draw bending technique, said bending head comprising:
 bend-form-clamp assembly set in rotation about an axis;   at least one roller having a tube or a profiled section clamped against the bend form clamp assembly during bending, the bend form clamp assembly being positioned in one of two bending starting positions being symmetric with respect to an axis of the tube, having a direction of bending starting from a first direction and an opposite direction starting from a second direction, the assembly being a bending head being comprised of a main platen rotating about a central first axis of a roller mounted concentrically on the first axis, and a clamp being parallel to the main platen and being mounted to rotate about a third axis, the third axis being mounted eccentrically on a satellite platen mounted to rotate about a second axis borne by the main platen and a predetermined distance away from the first axis.   
   
   
       2 . A bending machine for a rotary draw bending technique, the bending machine comprising:
 a bending head as claimed in  claim 1 ; and   a numerical control for all movements of components thereof.   
   
   
       3 . The bending machine as claimed in  claim 2 , wherein said numerical control calculates movements of components and bending parameters based on two planar coordinates and an angle of rotation, defining movements of the clamp. 
   
   
       4 . The bending machine as claimed in  claim 2 , wherein said numerical control also controls, in the conventional way, a guide-work rest means, a tube-positioning means, a mandrel-guide means and a tube-positioning means. 
   
   
       5 . The bending machine as claimed in  claim 1 , wherein a directions of bending are changed by rotating the axes in a symmetric structure.