Patent attributes
A pipe-bending machine mandrel includes a rigid member (5), inserted inside a pipe (T) which has an internal dimension Di and can tilt in a bending operation with a mean radius Rm as measured between the rotation center (O) of a bending die and the longitudinal axis (l) of the pipe (T). The rigid member (5) has a proximal side profile with respect to the rotation center (O) and includes a concave intermediate portion as generated by a radius Rci, and a distal side profile with respect to the rotation center (O) that includes two convex, divided, end portions as generated by respective radius Rce, where Rci=Rm−(Di/2)+t, and Rce=Rm+(Di/2)−t, t being a term varying according to the accuracy of the dimensional characteristics of the pipe and of the curve to be obtained.
