Anti-leak valve unit for overtube

Abstract

An anti-leak valve unit ( 1 ) is removably attached to a base end portion ( 43 ) of an overtube ( 4 ) that includes an inner cavity ( 42 ) through which an endoscope is to be removably inserted, and that is to be inserted into a body cavity. The anti-leak valve unit ( 1 ) includes a frame portion ( 3 ) attached to an outer circumferential surface ( 44 ) of the base end portion ( 43 ) of the overtube ( 4 ), a fitting device ( 2 ) provided on the frame portion ( 3 ) so as to be removably engaged with the outer circumferential surface ( 44 ) of the base end portion ( 43 ), and a valve element ( 5 ) provided inside the frame portion ( 3 ). The valve element ( 5 ) includes an annular endoscope insertion port located at a generally central portion of the valve element ( 5 ) so as to be circumferentially fitted to the endoscope, and a flexible elastic portion provided around the endoscope insertion port.

1 . An anti-leak valve unit for overtube, to be removably attached to a base end portion of an overtube to be inserted into a body cavity, said overtube including an inner cavity through which an endoscope can be removably inserted, comprising:
 a frame portion to be attached to an outer circumferential surface of said base end portion of said overtube;   a fitting device provided on said frame portion so as to be removably engaged with said outer circumferential surface of said base end portion; and   a valve element provided inside said frame portion;   wherein said valve element includes:   an annular endoscope insertion port located at a generally central portion of said valve element so as to be circumferentially fitted to said endoscope; and   a flexible elastic portion provided around said endoscope insertion port.   
     
     
         2 . The anti-leak valve unit for overtube according to  claim 1 ,
 wherein said fitting device is located two or more positions with a spacing from each other, around said frame portion.   
     
     
         3 . The anti-leak valve unit for overtube according to  claim 1 , to be attached to said overtube including a tube body to be inserted into said body cavity, said base end portion larger in diameter than said tube body, and a expanding portion formed in an increasing diameter from said tube body toward said base end portion;
 wherein said fitting device includes a lock portion projecting inwardly of said frame portion, so as to be removably engaged with an outer surface of said expanding portion.   
     
     
         4 . The anti-leak valve unit for overtube according to  claim 3 ,
 wherein said fitting device further includes:   a finger-engaging portion integrally formed with said lock portion, for switching said lock portion between a closed state that enables engagement with said expanding portion and an open state that enables removal from said expanding portion.   
     
     
         5 . The anti-leak valve unit for overtube according to  claim 1 , wherein said endoscope insertion port includes a straight tube portion extending thicknesswise of said valve element. 
     
     
         6 . The anti-leak valve unit for overtube according to  claim 1 , comprising a generally ring-shaped fixing member that fixes said valve element to said frame portion. 
     
     
         7 . The anti-leak valve unit for overtube according to  claim 1 , wherein said elastic portion includes a bellows portion. 
     
     
         8 . The anti-leak valve unit for overtube according to  claim 1 , comprising a reinforcing member located between an outer periphery of said endoscope insertion port and an inner periphery of said elastic portion. 
     
     
         9 . The anti-leak valve unit for overtube according to  claim 8 , wherein said reinforcing member is of an O-ring shape. 
     
     
         10 . The anti-leak valve unit for overtube according to  claim 1 , wherein an inner diameter of said endoscope insertion port is smaller than an outer diameter of said endoscope, by equal to or more than 0 mm and equal to or less than 5 mm. 
     
     
         11 . The anti-leak valve unit for overtube according to  claim 1 , further comprising a second valve element including a second endoscope insertion port and a second elastic portion, located on a distal end side of said valve element, with a spacing therefrom. 
     
     
         12 . The anti-leak valve unit for overtube according to  claim 11 , wherein said second endoscope insertion port is a hole or a slit through which said endoscope can be loosely inserted.