Patent US3992941A successfully refreshed from Google Patents.
US3992941A
Expired / Lapsed
US
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Liquid level measuring apparatus
Assignee: Individual
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Filing: 1974-06-10
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Granted: 1976-11-23
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Expires: 1994-06-10
Abstract
Abstract The level of liquid in a tank or a boiler is determined initially by enclosing the liquid in a column and then sensing the liquid surface in the column by causing a plunger to pass through the non-liquid medium in the column above the liquid to the liquid surface and noting the abrupt change in descent rate of the plunger when it hits the liquid surface due to the great difference between the viscosities of the non-liquid and liquid mediums. The level of liquid in the boiler is reflected on a continuing basis by permitting the plunger to float or levitate in or on the liquid as it is supported by an entrapped gas bubble. The difference in the position of the plunger when it encounters the liquid surface and the position of the plunger thereafter, as it is supported on the liquid is the correction factor that is maintained steadily until pressure or temperature changes necessitate a new determination of that difference with a fresh gas bubble at the current temperature and pressure. In a steam boiler, the plunger is hollow, vented at the bottom and rides in a vertical open cylinder. When the plunger is empty of water, it can "levitate" in the cylinder with the bottom of the plunger at the water level and so, the plunger level indicates water level in the boiler. A magnetic coupled plunger lifting mechanism completely external of the boiler couples magnetically to the plunger for doing the following: lifting the plunger; following the plunger position; and controlling the degree of levitation. By the magnetic coupling, magnetic forces pass between the plunger to an exterior rod and the rod initiates a display of plunger position.
Inventors
- 👤 Daniel J. McGoldrick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 23:12
CPC Classifications
G; G01; G01F; G01F23/00; G01F23/30; G01F23/64; G01F23/68; Y; Y10; Y10S; Y10S73/00; Y10S73/05
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
225 words
Apparatus for determining the level of liquid in a container which contains a liquid and a non-liquid medium at high pressure comprising, means for enclosing a portion of the liquid at the liquid level in a substantially vertical volumn partially open at both ends, the enclosed liquid being substantially entrapped in the lower portion of the column with a non-liquid medium extending upward from the liquid surface in the column, a plunger in the column providing a bottom plunger surface generally parallel to and juxtaposed to the liquid surface, the edge of said bottom plunger surface fitting slideably in the enclosing means so as to restrict substantially fluid flow in the column past the plunger, the plunger being adapted to descent in the column through the non-liquid medium toward the liquid medium, the plunger being at least partially open at the bottom so as to entrap vapor within the plunger, whereby the plunger descends until the weight of the plunger is balanced by the force of vapor rising from the liquid surface when the bottom plunger surface is at the liquid surface, and means coupled to the plunger for indicating the descent of the plunger in the column, whereby the point in the descent of the plunger at which an abrupt change of the plunger descent rate occurs is determinable to indicate the liquid level.
Claim 2
Dependent Claim
225 words
Apparatus for determining the level of liquid in a container which contains a liquid and a non-liquid medium at high pressure comprising, means for enclosing a portion of the liquid at the liquid level in a substantially vertical volumn partially open at both ends, the enclosed liquid being substantially entrapped in the lower portion of the column with a non-liquid medium extending upward from the liquid surface in the column, a plunger in the column providing a bottom plunger surface generally parallel to and juxtaposed to the liquid surface, the edge of said bottom plunger surface fitting slideably in the enclosing means so as to restrict substantially fluid flow in the column past the plunger, the plunger being adapted to descent in the column through the non-liquid medium toward the liquid medium, the plunger being at least partially open at the bottom so as to entrap vapor within the plunger, whereby the plunger descends until the weight of the plunger is balanced by the force of vapor rising from the liquid surface when the bottom plunger surface is at the liquid surface, and means coupled to the plunger for indicating the descent of the plunger in the column, whereby the point in the descent of the plunger at which an abrupt change of the plunger descent rate occurs is determinable to indicate the liquid level.
Claim 3
Dependent Claim
22 words
Apparatus as in claim 1 wherein, the indicating means coupled to the plunger moves with the plunger and is coupled thereto magnetically.
Claim 4
Dependent Claim
37 words
Apparatus as in claim 2 wherein, the plunger carries a magnet, the indicating means coupled to the plunger carries another magnet and the magnetic force between the magnets causes the indicating means to move with the plunger.
Claim 5
Dependent Claim
40 words
Apparatus as in claim 1 wherein, means are provided for lifting the plunger in the column, whereby the plunger can be lifted from the liquid level and released to descend in the column through the nonliquid medium to the liquid.
Claim 6
Dependent Claim
17 words
Apparatus as in claim 4 wherein, the means for lifting the plunger couples to the plunger magnetically.
Claim 7
Dependent Claim
22 words
Apparatus as in claim 5 wherein, the indicating means coupled to the plunger moves with the plunger and is coupled thereto magnetically.
Claim 8
Dependent Claim
109 words
Apparatus as in claim 6 wherein, the means for lifting and the indicating means include in common, a tube extending vertically into the container central of the column, the inside of the tube being sealed from the inside of the container, a rod inside the tube, one or more magnets attached to the plunger, one or more magnets attached to the rod which couples magnetically with the plunger magnets, and means for manipulating the rod in the tube, whereby lifting the rod lifts the plunger and releasing the rod releases the plunger so that the plunger descends in the column, and the indicating means is actuated by the rod.
Claim 9
Dependent Claim
88 words
Apparatus as in claim 7 wherein, the means enclosing the liquid in a vertical column is formed by a cylinder in the container, the cylinder having openings at the top and bottom, the opening at the bottom of the cylinder serving to restrict fluid flow between the cylinder and the container, the plunger is a ring-shaped body in the cylinder, the tube is concentric with the cylinder and plunger, the end of the tube inside the container is sealed, and the rod is accessible from outside the container.
Claim 10
Dependent Claim
54 words
Apparatus as in claim 8 wherein, the fit between the plunger and the cylinder and the fit between the plunger and the tube are such that flow of fluid in the column past the plunger as the plunger descends is restricted sufficiently to substantially impede the descent rate of the plunger in the column.
Claim 11
Dependent Claim
44 words
Apparatus as in claim 9 wherein, the container is a steam boiler, the liquid is water, the non-liquid medium includes water vapor, the tube extends into the boiler from the top thereof and the liquid level is the level of water in the boiler.
Claim 12
Dependent Claim
173 words
Apparatus for determining the level of liquid in a container which contains a liquid and a non-liquid medium comprising, means for enclosing a portion of the liquid at the liquid level in a substantially vertical column partially open at both ends, the encosed liquid being contained in the lower portion of the column with the non-liquid medium extending upward from the liquid surface in the column, a hollow plunger in the column fitting slideably in the enclosing means so as to restrict substantially fluid flow in the column past the plunger, The bottom of the plunger being generally parallel to and juxtaposed to the liquid surface, the plunger being at least partially open at the bottom so as to entrap vapor within the plunger, whereby the plunger descends until the weight of the plunger is balanced by the force of vapor rising form the liquid surface when the bottom of the plunger is at the liquid surface, and means coupled to the plunger for indicating the position of the plunger in the column.
Claim 13
Dependent Claim
173 words
Apparatus for determining the level of liquid in a container which contains a liquid and a non-liquid medium comprising, means for enclosing a portion of the liquid at the liquid level in a substantially vertical column partially open at both ends, the encosed liquid being contained in the lower portion of the column with the non-liquid medium extending upward from the liquid surface in the column, a hollow plunger in the column fitting slideably in the enclosing means so as to restrict substantially fluid flow in the column past the plunger, The bottom of the plunger being generally parallel to and juxtaposed to the liquid surface, the plunger being at least partially open at the bottom so as to entrap vapor within the plunger, whereby the plunger descends until the weight of the plunger is balanced by the force of vapor rising form the liquid surface when the bottom of the plunger is at the liquid surface, and means coupled to the plunger for indicating the position of the plunger in the column.
Claim 14
Dependent Claim
47 words
Apparatus as in claim 11 wherein, means are provided for lifting the plunger in the column, whereby the plunger can be lifted from the liquid level to drain the plunger of liquid and then released to descend in the column through the non-liquid medium to the liquid.
Claim 15
Dependent Claim
171 words
Apparatus for determining the level of liquid in a container which contains a liquid and a non-liquid medium comprising, means for enclosing a portion of the liquid at the liquid level in a substantially vertical column partially open at both ends, the enclosed liquid being contained in the lower portion of the column with the non-liquid medium extending upward from the liquid surface in the column, a hollow plunger in the column fitting slideably in the enclosing means, the bottom of the plunger being generally parallel to and juxtaposed to the liquid surface, the plunger being at least partially open at the bottom so as to entrap vapor within the plunger, whereby the plunger descends until the weight of the plunger is balanced by the force of vapor rising from the liquid surface when the bottom of the plunger is at the liquid surface, and indicating means magnetically coupled to the plunger so that said indicating means moves with the plunger for indicating the position of the plunger in the column.
Claim 16
Dependent Claim
171 words
Apparatus for determining the level of liquid in a container which contains a liquid and a non-liquid medium comprising, means for enclosing a portion of the liquid at the liquid level in a substantially vertical column partially open at both ends, the enclosed liquid being contained in the lower portion of the column with the non-liquid medium extending upward from the liquid surface in the column, a hollow plunger in the column fitting slideably in the enclosing means, the bottom of the plunger being generally parallel to and juxtaposed to the liquid surface, the plunger being at least partially open at the bottom so as to entrap vapor within the plunger, whereby the plunger descends until the weight of the plunger is balanced by the force of vapor rising from the liquid surface when the bottom of the plunger is at the liquid surface, and indicating means magnetically coupled to the plunger so that said indicating means moves with the plunger for indicating the position of the plunger in the column.
Claim 17
Dependent Claim
37 words
Apparatus as in claim 13 wherein, the plunger carries a magnet, the indicating means coupled to the plunger carries another magnet and the magnetic force between the magnets causes the indicating means to move with the plunger.
Claim 18
Dependent Claim
173 words
Apparatus for determining the level of liquid in a container which contains a liquid and a non-liquid medium comprising, means for enclosing a portion of the liquid at the liquid level in a substantially vertical column partially open at both ends, the enclosed liquid being contained in the lower portion of the column with the non-liquid medium extending upward from the liquid surface in the column, a hollow plunger in the column fitting slideably in the enclosing means, the bottom of the plunger being generally parallel to and juxtaposed to the liquid surface, the plunger being at least partially open at the bottom so as to entrap vapor within the plunger, whereby the plunger descends until the weight of the plunger is balanced by the force of vapor rising from the liquid surface when the bottom of the plunger is at the liquid surface, means coupled to the plunger for indicating the position of the plunger in the column and means for lifting the plunger in the column magnetically coupled to the plunger.
Claim 19
Dependent Claim
173 words
Apparatus for determining the level of liquid in a container which contains a liquid and a non-liquid medium comprising, means for enclosing a portion of the liquid at the liquid level in a substantially vertical column partially open at both ends, the enclosed liquid being contained in the lower portion of the column with the non-liquid medium extending upward from the liquid surface in the column, a hollow plunger in the column fitting slideably in the enclosing means, the bottom of the plunger being generally parallel to and juxtaposed to the liquid surface, the plunger being at least partially open at the bottom so as to entrap vapor within the plunger, whereby the plunger descends until the weight of the plunger is balanced by the force of vapor rising from the liquid surface when the bottom of the plunger is at the liquid surface, means coupled to the plunger for indicating the position of the plunger in the column and means for lifting the plunger in the column magnetically coupled to the plunger.
Claim 20
Dependent Claim
22 words
Apparatus as in claim 15 wherein, the indicating means coupled to the plunger moves with the plunger and is coupled thereto magnetically.
Claim 21
Dependent Claim
106 words
Apparatus as in claim 16 wherein, the means for lifting and the indicating means include in common, a tube extending vertically into the container substantially central of the column, the inside of the tube being sealed from the inside of the container, a rod inside the tube, one or more magnets on the plunger, one or more magnets on the rod which couple magnetically with the plunger magnets, and means for manipulating the rod tube, whereby lifting the rod lifts the plunger and releasing the rod releases the plunger so that the plunger descends in the column and the indicating means is actuated by the rod.
Claim 22
Dependent Claim
60 words
Apparatus as in claim 17 wherein, the means enclosing the liquid in a vertical column is formed by a cylinder in the container, the plunger is a ring-shaped body in the cylinder, the tube is concentric with the cylinder and plunger, the end of the tube inside the container is sealed and the rod is accessible from outside the container.
Claim 23
Dependent Claim
44 words
Apparatus as in claim 18 wherein, the container is a steam boiler, the liquid is water, the non-liquid medium includes water vapor, the tube extends into the boiler from the top thereof and the liquid level is the level of water in the boiler.
Claim 24
Dependent Claim
36 words
Apparatus as in claim 19 wherein, throttling means are provided inside the boiler at the bottom of the cylinder for controlling the rate of flow of vapor from the liquid into the bottom of the cylinder.
Claim 25
Dependent Claim
52 words
Apparatus as in claim 20 wherein, the sealed end of the tube extends into the throttling means and throttling control means are provided inside the tube which couple magnetically to the throttling means, whereby the throttling control means is adjustable from outside the boiler to vary the throttling means inside the boiler.
Claim 26
Dependent Claim
65 words
Apparatus as in claim 21 wherein, the throttling means includes a funnel-like channel oriented to intercept vapor rising in the liquid at the large end of the funnel and conduct the intercepted vapor into the bottom of the cylinder, and means for varying the effective intercepting area of the funnel, thereby varying the flow rate of the rising vapor into the bottom of the cylinder.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-11-23 | 1980-05-24 | 1980-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-11-23 | 1984-05-24 | 1984-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-11-23 | 1988-05-24 | 1988-11-23 | $7700.00 | Window Closed / Lapsed |