Waste disposal system and method

Claim 1

In a system for servicing waste receptacles of marine and other vehicle-equipped sanitary facilities, a coupler connectable to the waste receptacle to be serviced, a waste holding tank having an outlet connectable to an external sewer, a flushing fluid holding tank having an inlet connectable to a source of flushing fluid, a waste conduit interconnecting said coupler and waste holding tank, a flushing fluid conduit interconnecting said coupler and flushing fluid holding tank, and means for selectively applying vacuum and air pressure to the interiors of each of said tanks for sequentially effecting the withdrawal of waste into the waste holding tank from the receptacle, delivering a quantity of flushing fluid to the receptacle, withdrawal of the flushing fluid quantity into the waste holding tank and expulsion of said waste and flushing fluid quantity from the waste holding tank to said sewer, said means including an air pump having an inlet and outlet, an air conduit having connections with each of said tanks, a valve selectively operable to connect the air conduit to either of said pump inlet or pump outlet, and valves respectively operable to control air flow to and from said waste holding tank via said air conduit and flow of flushing fluid to and from said flushing fluid holding tank via said flushing fluid conduit, said air conduit connections with the tanks being located in the upper portions of the tanks and each including a valve seat and a fluid level responsive valve movable against the seat to block flow outwardly of the tank when the fluid level therein reaches a predetermined height, said means further including check valves in each of said waste holding tank outlet, flushing fluid tank inlet, and waste conduit, at least one of said check valves in the waste holding tank outlet and waste conduit comprising an elongated valve housing having an inlet at one end and an outlet at the other end, a fixed sleeve extending into the housing from said inlet, and an elongated hollow member sealingly secured at one end to the sleeve and having elastically yieldable sidewall portions extending toward said outlet and tapering toward each other to form a closure therebetween at their extended ends.