Patent ID: 6776183
Filing Date: 2004-08-17
Classification: B64C,B64D,Y10T

Abstract:
A drain device for interposition between a potable water line and a gray water line leading to an external drain, said device comprising:a housing defining a first chamber and a second chamber; an inlet adapted for connection to the potable water line; an outlet adapted for connection to the gray water line and communicating with the second chamber; and a piston movable within the housing between: a normal operation position, whereat the inlet communicates with the first chamber and the first chamber communicates with the second chamber, whereby potable water within the first chamber may flow into the second chamber, through the outlet to the gray water line and to the external drain; and a back-up operation position, whereat the first chamber is sealed from the second chamber, whereby gray water in the second chamber will be prevented from entering the first chamber; wherein: the first chamber is vented, thereby providing an air gap between the inlet and the second chamber; the piston, when in the back-up operation position, seals the inlet from the first chamber, whereby potable water in the inlet will not enter the first chamber; and back-up water in the second chamber will cause the piston to float from the normal operation position to the back-up operation position.