Method of hot bending a generally straight wire blank

摘要

A method of hot bending a generally straight wire blank of a material being brittle in cold condition into a wire element having straight end portions and coils formed therebetween. According to the invention the rod blank is hot bent without a mandrel by clamping the end portions of the rod blank by means of two clamping jaws. The rod blank is heated to a softening temperature in the central wire portion which is to form the coils of the finished wire element, while the end portions are kept at a lower temperature. During the bending process at least one of the clamping jaws is brought along a movement path adapted to the desired coil formation.