Improvements introduced in the manufacture of flexible pipes. (Machine-translation by Google Translate, not legally binding)

摘要

Improvements introduced in the manufacture of flexible tubes, which are characterized by the fact that a flexible plastic tube carries a helical fold, this fold being occupied internally by a wire coiled in helical spring and said fold being internally closed to house the wire in a as a helical continuous bag. (Machine-translation by Google Translate, not legally binding)