Flexible tube with thin walls and high strength - comprises high helical reinforcing insert of greater breadth than height in soft PVC tube, esp. equilateral triangle shaped insert with apex near outer tube wall

摘要

A flexible tube (1) has a higher strength, helical reinforcing insert (3) embedded in it. The insert (3) cross-section has a greater breadth than height and is pref. an equilaterial triangle. The triangle (3) apex is near the outer tube wall. Soft PVC is used for the tube wall (1) and a harder PVC for the reinforcing insert (3). ADVANTAGE - The reinforcement cross-section allows a thinner tube wall, which saves material, yet gives equal strength.