초록 ▼

A pump operable in response to the level of the liquid to be pumped comprising an impeller, a motor for rotating the impeller, a discharge passage for receiving the liquid pumped by the impeller, and a sensing chamber communicating with the discharge passage between the impeller and the pump outlet

A pump operable in response to the level of the liquid to be pumped comprising an impeller, a motor for rotating the impeller, a discharge passage for receiving the liquid pumped by the impeller, and a sensing chamber communicating with the discharge passage between the impeller and the pump outlet so that liquid in the discharge passage can trap gas in the sensing chamber. A pump controller is responsive to the pressure of the trapped gas in the sensing chamber for energizing and di-energizing the motor. Energizing of the motor to cause the impeller to pump liquid into the discharge passage substantially increases the pressure of the trapped gas to thereby assure that the pump remains on.

대표청구항 ▼

A pump having an inlet and operable in response to the level of liquid to be pumped wherein said level is variable, said pump comprising: an impeller for pumping liquid, said impeller having a periphery and an inlet which is positionable to receive the liquid; means for driving the impeller to cause

A pump having an inlet and operable in response to the level of liquid to be pumped wherein said level is variable, said pump comprising: an impeller for pumping liquid, said impeller having a periphery and an inlet which is positionable to receive the liquid; means for driving the impeller to cause the impeller to pump the liquid and to provide the liquid under pressure; passage means for receiving the liquid under pressure from the impeller; means for permitting the liquid to pass from the inlet side of the pump into the passage means when the impeller is not being driven by the driving means whereby the passage means receives liquid as the liquid level rises and also receives the liquid under pressure from the impeller; means defining a sensing chamber which is open to the liquid at a location where it can receive the liquid under pressure from the impeller and where it can receive the liquid which passes into the passage means when the impeller is not being driven whereby gas in the sensing chamber can be compressed and the pressure of the gas increases with an increase in height of the level of the liquid; said location being at least partially radially inwardly of said periphery; means for providing a fluid path from the liquid being pumped radially inwardly of the periphery of the impeller to said location without passing around said periphery whereby the pressure sensed by the sensing chamber is less than the pressure at said periphery; control means responsive to the pressure of the gas in the sensing chamber reaching about a first magnitude for causing said driving means to drive said impeller to pump the liquid into the passage means and responsive to the pressure in the sensing chamber dropping to a second magnitude to terminate the driving of the impeller by the driving means; and the pumping of liquid by the impeller elevating the pressure of the gas in the sensing chamber to a magnitude which is above said first magnitude.