| 摘要 |
PROBLEM TO BE SOLVED: To surely transmit twisting force to an end part by increasing the rigidity of an opposite-direction element wire bunch, which is wound in the direction opposite to the winding direction of a spiral tube in a net adhered to the outer periphery of a spiral tube, compared with the same-direction ele ment wire bunch so as to prevent a flexible part itself from being deformed and absorbing twisting force when the twisting force is acted on the flexible part even if a metallic spiral tube of single layer type is adopted in order to reduce the diameter of the flexible part. SOLUTION: The net 12 to be mounted to the outer periphery of the spiral tube 11 consisting of a single layer consists of the same-direction element wire bunch 18L wound in the same direction as the winding direction of the tube 11 and the opposite-direction element wire bunch 18R to be wound in the direction opposite to the winding direction of the tube 11. In this bunch 18R, the number of the element wires constituting the bunch 18R is made larger than that of the bunch 18L, or its material is made harder than the bunch 18L or the diameter of the element wires is larger than the bunch 18L. Thus, the rigidity of the bunch 18R is increased compared with the bunch 18L in the net 2.
|
