| 摘要 |
PROBLEM TO BE SOLVED: To provide a flexible tube for an endoscope which suppresses contraction in the longitudinal direction when a pressure difference occurs between the inside of the flexible tube and the outside of it and a highly reliable endoscope equipped with the flexible tube for the endoscope. SOLUTION: The insertion portion flexible tube 1 has a tubular core material 2 and an outer shell 3 coating the periphery of the core material 2. The core material 2 has an inner helical tube 211 and an outer helical tube 212 which is provided on the periphery of the inner helical tube 211 and is wound in the direction opposite to the direction in which the inner helical tube 211 is wound, and a net tube 22 coating the periphery of the outer helical tube 212. The insertion portion flexible tube 1 is configured with the inner helical tube 211 and the outer helical tube 212 which are formed of strip-shaped materials having the same bending elasticity and different pitches, and a constant of spring of the inner helical tube 211 is set to be greater than that of the outer helical tube 212. Consequently, the insertion portion flexible tube is constituted to prevent or to suppress the contraction in the longitudinal direction due to the pressure difference occurring between the inside of the insertion portion flexible tube 1 and the outside of it. COPYRIGHT: (C)2007,JPO&INPIT
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