Method and apparatus of bending metal elongate materials

Abstract From the Canadian patent

A method of and an apparatus for bending an elongate metal element, such as a pipe, are disclosed. An arm is secured to each end of the element portion to be bent and with a pulling device such as a chain hydraulic cylinder or the like connecting the arms. The pulling device is operated to exert a bending moment on the element that is insufficient to cause its permanent deformation. A local bending stimulation is then applied to and moved along the pipe to cause the required bending. The stimulator may be a mechanical roll or press bender or it may simply be a heater. The arrangement may be such that a large compressive force is applied to the workpiece to prevent wall thinning on the …