Bidirectional pump with diaphragm operated valve for dishwasher

Abstract From the Canadian patent

A bidirectional pump has a chamber in communication both with a drain conduit and a conduit for delivering washing liquid into a wash chamber. The drain conduit has a port communicating between the pump chamber and a drain outlet. An opening communicates between the delivery and drain conduits and is selectively sealed by a deformable diaphragm. With the pump rotating in a first direction and the liquid being delivered principally through the delivery conduit by the pump, a pressure differential is established across the diaphragm thereby urging a portion of the diaphragm sealingly against the port to prevent delivery of washing liquid through the drain conduit as during a rinsing cycle of …