Connecting device

A connecting device for connecting a gastight endoscope to a gas supply unit comprising:

• a first connector attached to the endoscope, said first connector including:
• a communication pipe which is secured to the endoscope, and which has first and second ends communicating with the inside and outside of the endoscope, respectively, and the second end portion extending outward from the endoscope,
• a first retainer projecting outward from the second end portion of the communication pipe,
• a ring-shaped rotating body fitted to the outside of the second end portion of the communication pipe to be rotatable between first and second positions, and having an engaging portion on the outer peripheral surface thereof, and
• a valve plug disposed in the communication pipe to be movable in conjunction with the rotation of the rotating body between a closing position where the valve plug closes the communication pipe and an opening position where the valve plug allows gas to flow through the communication pipe, the valve plug being located in the closing position when the rotating body is in the first position and in the opening position when the rotating body is in the second position;
• and
• a second connector communicating with the gas supply unit and adapted to be connected to the first connector, said second connector including:
• a substantially ring-shaped housing which is to be fitted to the first connector in a gastight manner, for rotation relative to the first connector, the housing having an engaging slit adapted to engage the first retainer when the housing is rotated after being fitted to the first connector, so that the housing is prevented from coming off of the first connector, and
• a second retainer projecting inward from the housing, the second retainer being adapted to engage with the engaging portion of the rotating body when the housing is fitted to the first connector, and to rotate the rotating body to move the valve plug from the closing position to the opening position when the housing is rotated from the fitting position, the second retainer being allowed to engage with and disengage from the engaging portion only when the rotating body is in the first position.