Liquid feed device for intracavitary examination instrument

Claim 1

A liquid feed device for an endoscopic insertion instrument or the like, said liquid feed device comprising: a hermetically closed liquid feeder tank containing a supply of a feed liquid; a liquid feed pipe hermetically led into said feeder tank and having a liquid intake end thereof dipped in said feed liquid in said tank to supply said liquid to a liquid supply passage in an intracavitary insertion instrument; a pressurizing pipe hermetically led into said liquid feeder tank and having a pressure delivering end thereof opened over a liquid surface in said tank to apply pressure thereon; an atmospheric pipe having one end thereof hermetically led and opened into said liquid feeder tank and having the other end disposed outside said liquid feeder tank in communication with the atmosphere; and a valve assembly mounted on a pressure discharge opening at a lower distal end of said atmospheric pipe within said feeder tank to keep same closed while in a submerged position under the liquid surface in said feeder tank and to uncover said pressure discharge opening when brought into an exposed position above said liquid surface in said feeder tank; said liquid feed pipe and atmospheric pipe having flexible pipe portions formed of a flexible material of greater specific gravity than said feed liquid in said tank and suspended flexibly within said feeder tank to hang down always in a vertical position by gravity and in such a way as to hold the intake end of said liquid pipe in a deeper position than said pressure discharge opening of said atmospheric pipe relative to said liquid surface even when said feeder tank is turned from an upright position into a tilted position through a certain angle or vice versa.