| 摘要 |
PROBLEM TO BE SOLVED: To improve expanding/shrinking properties and heat insulation by fixing flanges for fitting to both end parts of a double cylindrical material composed of a flexible inner cylindrical material and a flexible outer cylindrical material and fitting a ring for holding the formation to the flexible inner cylindrical material. SOLUTION: A flexible duct is composed of the flexible inner cylindrical material, the flexible outer cylindrical material independently covered on the inner cylindrical material and a flexible cover independently covering the outer cylindrical material 13. The flanges 15, 16 for fitting are fixed to both end parts of this triple cylindrical material and, in the flexible inner cylindrical material 12, at least one of e.g. two rings 17, 18 for holding the formation are fitted onto the intermediate part of the axial direction with mutually prescribed interval. Shifting and expanding/shrinking movements in the axial direction of the flexible inner cylindrical material and the flexible outer cylindrical material are not limited by the rings 17, 18 for holding the formation, and the flexible inner cylindrical material and the flexible outer cylindrical material can sufficiently be deformed following the shifting and shaking movement in the axial direction of a roll.
|
