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US 3,939,383 AGranted
Liquid level monitoring device
AssigneeThe Wickes Corporation
InventorGerald F. Alm
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AssigneeThe Wickes Corporation
InventorGerald F. Alm
Estimating the term…
A liquid level monitoring device operable either to detect leakage from a body of liquid or to detect deviations from a controlled rate of withdrawal from a body of liquid. The device employs a pressure responsive diaphragm which, in the face of unequalized pressures applied to its opposite sides, is operable to actuate a control switch. One side of the diaphragm is exposed to a constant pressure, which may be atmospheric, while the other side of the diaphragm is connected to an open ended probe submerged in the body of liquid. When employed as a leak detector, the device is set by opening a solenoid controlled valve connected across a diaphragm to equalize pressure at opposite sides of the diaphragm while the probe is submerged in the body of liquid. Subsequent dropping of the level in the body of liquid after closure of the valve will reduce the head pressure sensed by the probe, thus unequalizing the pressure across the diaphragm to actuate the control switch which may, for example, be connected to trigger an alarm. A second by-pass connected across opposite sides of the diaphragm in parallel with the first by-pass includes a variable restricted orifice which provides a sensitivity adjustment in the leak detecting operation. By opening the orifice in the second by-pass to a selected opening, the device may be employed to monitor dropping of the liquid level at a selected rate.
A liquid level monitoring device comprising flexible pressure responsive diaphragm means, first pressure applying means for applying to one side of said diaphragm means a pressure variable in response to variations of level of a body of liquid being monitored, second pressure applying means for applying a constant pressure to the opposite side of said diaphragm means, first normally closed by-pass valve means operable in an open position to equalize the pressure on the opposite sides of said diaphragm means, second by-pass means connected in parallel with said first by-pass means establishing communication between opposite sides of said diaphragm means, sensitivity adjustment means in said second by-pass means for selectively blocking or adjustably restricting flow through said second by-pass means, and control means responsive to an unequalized pressure on opposite sides of said diaphragm means for opening said first by-pass valve means.
A liquid level monitoring device comprising differential pressure responsive means, first pressure applying means for applying to one side of said pressure responsive means a first pressure variable in accordance with variations of the level of a body of liquid being monitored, second pressure responsive means for applying a constant pressure to the opposite side of said pressure responsive means, by-pass conduit means by-passing said pressure responsive means operable in a first condition to connect said first and said second pressure applying means to each other to equalize the opposing pressures applied to said pressure responsive means and operable in a second condition to selectively isolate said first and second pressure responsive means from each other or to place said first and second pressure responsive means in communication with each other via variably restricted orifice means, and control means responsive to the sensing of a differential pressure by said pressure responsive means for establishing said by-pass means in said first condition.
A liquid level monitoring device comprising differential pressure responsive means, first pressure applying means for applying to one side of said pressure responsive means a first pressure variable in accordance with variations of the level of a body of liquid being monitored, second pressure responsive means for applying a constant pressure to the opposite side of said pressure responsive means, by-pass conduit means by-passing said pressure responsive means operable in a first condition to connect said first and said second pressure applying means to each other to equalize the opposing pressures applied to said pressure responsive means and operable in a second condition to isolate said first and second pressure responsive means from each other, control means responsive to the sensing of a differential pressure by said pressure responsive means for establishing said by-pass means in said first condition, and reset means in said control means operable to establish said by-pass means in said second condition when said pressure responsive means senses equalized pressures.
Dependencies are inferred from the claim text.