| 摘要 |
PROBLEM TO BE SOLVED: To provide a flexible tube 18 that can maintain watertightness for a long period.SOLUTION: The flexible tube 18 includes an inner layer 20, a seal layer 22 and an outer layer 24. The inner layer 20 is formed of a first, hard strip wound helically. The inner layer 20 includes many first elements 26. The seal layer 22 is formed of a second, soft strip wound helically. The seal layer 22 includes many second elements 28. The outer layer 24 is formed of a third, hard strip wound helically. The outer layer 24 includes many third elements 30. Each second element 28 extends over two first elements 26. The second element 28 is joined to the first elements 26. The third element 30 is joined to the second element 28 in the neighborhood of a rear edge 58 thereof. The third element 30 is not joined to the second element 28 in the neighborhood of a front edge 56 thereof. |
