Ventilation/feedwater switching apparatus for endoscope

A ventilation and feedwater switching apparatus for an endoscope, said apparatus comprising:

• a tubular body having an upper and a lower end and having an axis that extends from said upper to said lower end;
• and said tubular body being closed at said lower end;
• said tubular body having a feedwater inlet, a feedwater outlet, a ventilation inlet and a ventilation outlet formed therein;
• said tubular body being adapted to be disposed in the operating end of an endoscope in such a manner as to have said feedwater inlet and said ventilation inlet connected respectively to a feedwater supply line and to an air supply line of an endoscope in which said apparatus is disposed, and in such a manner as to have said feedwater outlet and said ventilation outlet connected respectively to a feedwater tube and a ventilation tube of the endoscope;
• a sliding valve body having a central bore and received axially slidably, sealingly and removably in said tubular body;
• said sliding valve body having an upper and a lower end, its said lower end being received in said tubular body;
• said central bore communicating with the exterior of an endoscope in which said apparatus is disposed;
• and said sliding valve body having an air delivery port formed therein, said central bore communicating via said air delivery port with said ventilation outlet of said tubular body;
• said sliding valve body having a groove formed therein in such a manner as to permit said feedwater inlet and said feedwater outlet of said tubular body to communicate via said groove when said sliding valve body is in a first axial position in said tubular body;
• and said sliding valve body having a passage defined therein for permitting said ventilation inlet of said tubular body to communicate with said central bore when said sliding valve body is in a second axial position in said tubular body;
• a check valve body detachably disposed at said lower end of said sliding valve body for closing said air delivery port in such a manner that if the communication of said central bore with the exterior of an endoscope in which said apparatus is disposed is blocked, the increasing internal air pressure in said central bore will force said check valve body to move to allow air to pass from said central bore to said ventilation outlet, thereby to allow the air to be fed into a coeliac cavity through the distal end of the endoscope;
• and
• a spring urging said sliding valve body to maintain it in said second axial position.