| 摘要 |
PURPOSE: A flexible tube is provided to prevent the sudden change of strength and stress concentration when high internal pressure is applied. CONSTITUTION: A flexible tube comprises one or more folding bellows having a plurality of spiral members. The spiral members are formed in a wall of a tube to pass through the exterior of the tube and kept from separating in the longitudinal axis of the tube. Each spiral member has two opposed bending sections and two restricted extension sections which are arranged between the opposed bending sections. The outer surface of the spiral member in the restricted extension sections is lower than the outer surface of the spiral member in the bending sections and higher than the outer surface of the tube. |
