| 摘要 |
A method and apparatus for shaping thermoformable elongate material, such as straight tube or rod, into arcuate shapes, such as helical coils, simple circular bends and the like, without kinks or sharp bends includes preforming a female mandrel with an interior forming surface of predetermined curvature, positioning the material adjacent one end of the mandrel, heating the material to its softening point prior to bending by the mandrel, moving the material through the mandrel relative to the mandrel interior surface so that the material assumes the shape of the interior surface, cooling the material so that it retains its newly formed shape, and then removing the cooled material from the mandrel. The mandrel can be operated with reduced internal pressure so that the material is held against the interior surface of the mandrel as it is moved.
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