Heated needles for perforating e.g. sheets or plates - esp. for foam baths mats and sheets for agricultural irrigation

摘要

Needles are carried in a movable frame and heated by gas or electricity. The needles are in interchangeable sets forming straight lines or curves. Needles of suitable cross-section are used to produce shapes unattainable by boring, welding or stamping. With thermoplastic materials the work cycle could be shortened by the use of cooling jets or fans. The tooling is simple and the method cheap.