Heated mandrel for bending plastics piping

摘要

A heated mandrel, such as for insertion into plastics piping to heat it for bending into a required shape, is a hose (3) which can bend containing a coil spring (7) fixed at both sides and a bending roller (6) within the spring (7).Cables (8) are passed round the bending roller (6), at the intervals of the coil spring (7) pitch, fixed in the centre and with their free ends at one side of the roller (6) at the spring coils (7) and at the other side passed alongside a tensioning wire between the spring (7) coils.Levers (9,10), which can be set against each other, are at the hose (3) and the roller (6), with a spring holder to keep them in their set position so that, when the roller (6) is rotated on the coil spring (7), a defined bending force is exerted to be transferred to the pipe to be bent through the hose (3) of the heated mandrel and, with heat, a defined bend is applied to the pipe.A wound strip material (4) contains graphite.