CYLINDER PISTON MECHANISM, FLOW PASSAGE SWITCHING CYLINDER PISTON MECHANISM, AND CYLINDER PISTON MECHANISM FOR ENDOSCOPE OPERATING MEMBER

摘要

PROBLEM TO BE SOLVED: To obtain an easy-maintenance cylinder piston mechanism with small sliding resistance. SOLUTION: In the cylinder piston mechanism having a pressable piston member with the tip part thereof inserted in a guide cylinder, comprising an end face annular recessed part formed at the outer edge of the tip part of the piston member with its side face part facing the inner peripheral surface of the guide cylinder and its side face part facing toward the inside of the guide cylinder opened, and an elastically deformable annular sealing member supported by the annular recessed part in the end face and fitted to the inner peripheral surface of the guide cylinder to seal a space between the inner peripheral surface of the guide cylinder and the piston member to block a fluid flow, the annular sealing member is fixed to the end face annular recessed part without a gap and is elastically deformed to protrude from the tip part of the piston member.