Abstract: An electrical motor operated sump pump has a motor mounted above a centrifugal sump pump. The motor is fully enclosed in a chamber in which the top plate of the pump is the bottom wall. The motor is provided with a casing having air inlet openings in a bottom wall and outlet openings at its top with an upwardly directed internal fan providing a downward flow of air surrounding the casing and inwardly across the top surface of the pump housing, to provide efficient cooling. When the sump water reaches the set limit to operate the pump, the lateral wall of the chamber in which the motor is mounted, this furnishes additional cooling of the circulated air.

Abstract: A pressure responsive pumping system comprising a motor driven impeller pump, a pressure responsive switch controlling the pump motor, and a pressure-sensing device comprising a tube extending through a side wall of the pump casing and slidable substantially radially thereof, a port adjacent the inner end of the tube, and a conduit connecting the outer end of the tube to the switch. More specifically an impeller pump having a flat end wall, an opening in its peripheral wall, a channel at the inner side of the end wall in alignment with the opening, and a tube slidable longitudinally through the opening and along said groove having a port at its inner open end, or at a side thereof adjacent its inner closed end.

Abstract: A sump pump having a float to initiate pumping and a flow-actuated device to continue pumping until the sump is substantially empty. The device may be in the form of a check valve held open by flow during pumping, and having a position which mechanically retains a motor switch closed.