CONTROLLER FOR A LIQUID SUPPLY PUMP
1 Assignment
0 Petitions
Accused Products
Abstract
A controller (30) for operating a pump associated with a liquid supply system. The controller includes a pressure unit comprising a housing (34a, 34b, 34c) having a liquid inlet (98) and a liquid outlet (39, 130). A biased (42) diaphragm (40) within the housing acts against liquid pressure within the housing between the inlet and the outlet. A control circuit (50) which includes a Hall effect sensor is mounted on the housing and is responsive to movements of the diaphragm (40) via a magnet (80) associated with the diaphragm. Thus the Hall effect sensor generates signals related to pressures within the housing from which a rate of pressure change is determined. A threshold pressure value at which the control circuit (50) is operative to switch on the pump is varied in dependence upon the rate of pressure change.
28 Citations
38 Claims
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1-19. -19. (canceled)
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20. A controller for operating a pump associated with a liquid supply system, the controller including:
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a pressure unit including a housing having an inlet for connection to the liquid supply and an outlet for delivery of the liquid to a consumer, a control circuit mounted on the housing and including a sensor, wherein the pressure unit and the sensor are operably associated such that the sensor generates signals related to pressures within the pressure unit, and wherein the control circuit is operative to determine from the signals generated by the sensor a rate of pressure change within the pressure unit to vary, in dependence upon the rate of pressure change, a threshold pressure value at which the control circuit is operative to switch on the pump to pressurize the liquid supply for delivery to the consumer. - View Dependent Claims (21, 22, 23, 24, 25, 31, 32, 36)
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26. A controller for operating a pump associated with a liquid supply system for the pump to pressurize the liquid supply, the liquid supply system having a closed head pressure, the controller including:
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a pressure unit including a housing having an inlet and a outlet, a diaphragm within the housing which is biased to act against the pressure of the liquid supply between the inlet and the outlet when a liquid supply is connected to the inlet, wherein the bias on the diaphragm is such that the diaphragm remains in substantially one position whilst the liquid supply pressure within the housing is at the closed head pressure, wherein said one position depends upon the closed head pressure and may differ for the controller in different liquid supply systems, a circuit structure carrying a control circuit for operating the pump for supplying liquid to and through the housing, the control circuit including a sensor which is mounted on the circuit structure such that it is operably associated with the diaphragm for sensing positions of the diaphragm as the diaphragm moves away from said one position in response to liquid pressures within the housing below the closed head pressure, wherein the sensor provides signals to the control circuit indicative of liquid pressures within the housing for the control circuit, whilst there is a liquid flow through the housing, to operate the pump when the sensor provides a signal indicative of a liquid pressure within the housing that is a predetermined value below the closed head pressure such that the liquid supply pressure is maintained within a predetermined range from the closed head pressure. - View Dependent Claims (27, 28, 29, 30)
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33. A controller for operating a pump associated with a liquid supply system, the controller including:
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a pressure unit including a housing having an inlet for connection to the liquid supply and an outlet for delivery of the liquid to a consumer, a circuit structure carrying a control circuit for operating the pump for supplying liquid to and through the housing, the control circuit including a liquid flow sensor, wherein the housing includes an aperture and the circuit structure is mounted on the housing such that the liquid flow sensor is exposed to liquid within the housing, wherein the inlet of the housing includes a valve for allowing a flow of the liquid into the housing from the inlet and preventing a reverse flow of the liquid from the housing into the inlet; wherein the valve is shaped such that a flow of the liquid into the housing is directed towards the liquid flow sensor, wherein the liquid flow sensor provides a flow signal to the control circuit to recognize there is a liquid flow through the housing. - View Dependent Claims (34, 35)
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37. A pressure unit for a liquid supply system for delivery of the liquid to a consumer, the liquid supply having a closed head pressure, the pressure unit including:
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a housing having an inlet and an outlet, a diaphragm within the housing which is biased to act against the pressure of the liquid supply between the inlet and the outlet when a liquid supply is connected to the inlet, wherein the bias on the diaphragm is such that the diaphragm remains in substantially one position whilst the liquid supply pressure within the housing is at the closed head pressure (wherein said one position depends upon the closed head pressure and may differ for the controller in different liquid supply systems) and the diaphragm moves away from said one position when the liquid supply pressure within the housing decreases, wherein the diaphragm is associated, on its side that is not exposed to the liquid supply, with a moveable member having pressure indicia, wherein the housing includes a window and the window and moveable member are such that for the diaphragm in said one position, a pressure indicium indicating the closed head pressure is exposed and for movement of the diaphragm away from the first position, a pressure indicium indicating a decreased pressure is exposed.
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38. A method for pressurizing a liquid supply in a liquid supply system having a closed head pressure, the liquid supply system including a pump for pressurizing the liquid supply wherein the pump is operated when the liquid supply pressure falls to a threshold pressure value below the closed head pressure, the method including the steps of:
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(i) determining the closed head pressure of the liquid supply system, (ii) measuring changes in pressure of the liquid supply due to a flow of liquid from the liquid supply, calculating a rate or pressure change from the measurements of step (ii), varying the threshold pressure value for operating the pump in dependence upon the calculated rate of pressure change, wherein the threshold pressure value is increased for relatively large rates of pressure change and is decreased for relatively low rates of pressure change.
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Specification