Patent ID: 6860516

Claim:
In a channel tube coupling structure for an anti-pollution endoscope in which a plurality of tubes extend in parallel in an axial direction within a channel tube that is disposed within an outer sheath that is detachably attached to and covers an insertion portion of the endoscope, and the plurality of tubes are freely coupled to and separated from corresponding endoscope side tubes respectively at a base end portion of the channel tube extending from a base end of the outer sheath, the channel tube coupling structure for the anti-pollution endoscope comprising: side holes respectively communicate with the plurality of tubes, and are formed at a side surface in a vicinity of the base end portion of the channel tube, the side holes being staggered with respect to one another in a axial direction; a coupling hole where the base end portion of the channel tube is loosely inserted thereinto and drawn freely therefrom so as to provide a space in a radial direction between the channel tube and the coupling hole; and annular sealing members, provided within the coupling hole, that seal portions between the respective side holes when the base end portion of the channel tube is inserted into the coupling hole; wherein the endoscope side holes are opened at an inner peripheral surface of the coupling hole, and located at portions between the annular sealing members, respectively.