Method of and apparatus for determining the level of liquid in a vessel
First Claim
1. A method of determining the quantity of a liquid in a variably filled container of known volume wherein a gas space is provided above said liquid in said container, the method comprising the steps of:
- (a) selectively forcibly moving at least a portion of one of the walls of the container so as to vary the volume of said gas space briefly and thereafter permitting the pressure in said space to oscillate with a natural frequency, said portion being plastically deformable;
(b) transforming the oscillation of said pressure in said space into a signal of an amplitude varying with the frequency of said oscillation;
(c) detecting the period of said signal and calculating the volume of said gas space as a function of said period; and
(d) indicating the difference between the volume of said gas space and the known volume of said container as a measure of the volume of the liquid in said container.
1 Assignment
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Accused Products
Abstract
A container of known volume, such as a fuel tank of an automotive vehicle, is provided with a loudspeaker-like membrane which can be energized to produce a pressure pulse in the gas space above the liquid in the container. The oscillations of this gas space are then converted into a signal via the diaphragm and the period of the signal is determined to provide the volume of the gas space. This is subtracted from the gas volume of the container automatically to indicate the liquid volume and the liquid volume can be displayed on the dashboard of the vehicle.
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Citations
16 Claims
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1. A method of determining the quantity of a liquid in a variably filled container of known volume wherein a gas space is provided above said liquid in said container, the method comprising the steps of:
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(a) selectively forcibly moving at least a portion of one of the walls of the container so as to vary the volume of said gas space briefly and thereafter permitting the pressure in said space to oscillate with a natural frequency, said portion being plastically deformable; (b) transforming the oscillation of said pressure in said space into a signal of an amplitude varying with the frequency of said oscillation; (c) detecting the period of said signal and calculating the volume of said gas space as a function of said period; and (d) indicating the difference between the volume of said gas space and the known volume of said container as a measure of the volume of the liquid in said container. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An apparatus for determining the volume of a liquid in a container having known volume and a variable quantity of liquid disposed below a gas space in said container, said apparatus comprising:
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a diaphragm plastically deformable and forming a portion of a wall of said container and reversibly displaceable to vary the volume of said space therein; electromotive means connected to said diaphragm; an excitation signal source connectable to said electromotive means for selectively forcibly displacing said diaphragm to briefly change the volume of said gas space and induce pressure oscillation therein, said pressure oscillation oscillating said diaphragm; detector means connected to said diaphragm for generating a signal responsive to the pressure oscillation in said gas space and means responsive to the pressure oscillation in said gas space; and means responsive to said detector means for determining the period of said signal and thereby establishing the volume of said gas space and providing an output representing the difference between the known volume of said container and the volume of said gas space corresponding to the volume of the liquid in said container.
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10. An apparatus for determining the volume of a liquid in a container having known volume and a variable quantity of liquid disposed below a gas space in said container, said apparatus comprising:
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a diaphragm forming a plastically deformable but reversibly displaceable wall of said container and displaceable to vary the volume of said space therein; electromotive means connected to said diaphragm; an excitation signal source connectable to said electromotive means for forcibly displacing said diaphragm to briefly change the volume of said gas space and induce pressure oscillation therein, said pressure oscillation oscillating said diaphragm; detector means connected to said diaphragm for generating a signal responsive to the pressure oscillation in said gas space and means responsive to the pressure oscillation in said gas space; and means responsive to said detector means for determining the period of said signal and thereby establishing the volume of said gas space and providing an output representing the difference between the known volume of said container and the volume of said gas space corresponding to the volume of the liquid in said container, said electromotive means is connected in circuit with a bistable switch means alternately connecting said electromotive means and said detector means with said source. - View Dependent Claims (11, 12, 13, 14, 15, 16)
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Specification