Patent US5002020A successfully refreshed from Google Patents.
US4777832A
Expired / Lapsed
US
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Liquid level sensor, used in an automatic station for preparing immunologic dosages
Assignee: CHEMILA Srl
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Filing: 1986-11-14
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Granted: 1988-10-18
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Expires: 2006-11-14
Abstract
Abstract A new liquid level sensor, suitable for use as an auxiliary device in an automatic station for preparing immunologic dosages, consists of a U pipe containing water, and provided with a resistivity sensor at the end of one of its branches, the other branch being connected with the terminal of the liquid dispensing or suction system of the automatic station in such a way that a very small pressure difference within the system results in a water level variation in both branches and in the relevant activation (or disactivation) of the resistivity sensor.
Inventors
- 👤 Armando Prodosmo
- 👤 Federico Mazzacurati
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:14
CPC Classifications
G; G01; G01N; G01N35/00; G01N35/10; G01N35/1081; G01N35/109; G01F; G01F23/00; G01F23/22; G01F23/24; G01F23/241; G01N35/1009; G01N2035/1025
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
111 words
A liquid level operated sensor suitable for use in connection with an automatic station for suction or dispensing of liquids in containers which comprises a U-shaped container means having first and second legs, a conductive fluid in said container means and incompletely filling said container means, a resistivity sensor capable of providing an output signal disposed in the first leg of said container means, and means to connect the second leg to a pressure operated apparatus such that minimal change in the pressure in said apparatus is communicated to the conductive fluid in said container means and causes the conductive fluid to move into or out of contact with said sensor.
Claim 2
Dependent Claim
111 words
A liquid level operated sensor suitable for use in connection with an automatic station for suction or dispensing of liquids in containers which comprises a U-shaped container means having first and second legs, a conductive fluid in said container means and incompletely filling said container means, a resistivity sensor capable of providing an output signal disposed in the first leg of said container means, and means to connect the second leg to a pressure operated apparatus such that minimal change in the pressure in said apparatus is communicated to the conductive fluid in said container means and causes the conductive fluid to move into or out of contact with said sensor.
Claim 3
Dependent Claim
14 words
The sensor of claim 1 wherein said means to connect comprises a valve means.
Claim 4
Dependent Claim
15 words
The sensor of claim 2 wherein said valve means is an electrically controlled valve means.
Claim 5
Dependent Claim
27 words
The sensor of claim 1 wherein said sensor is disposed in said first leg at a point which is normally out of contact with said conductive fluid.
Claim 6
Dependent Claim
22 words
The sensor of claim 4 wherein said sensor is disposed at the end of said first leg remote from said second leg.
Claim 7
Dependent Claim
15 words
The combination, a pressure operated apparatus and the liquid level operated sensor of claim 5.
Claim 8
Dependent Claim
25 words
The sensor of claim 1 further comprising means to cause the resistivity sensor to generate an output signal when in contact with said conductive fluid.
Claim 9
Dependent Claim
30 words
The sensor of claim 7 further comprising means to control the pressure in said apparatus in response to the output signal of said resistivity sensor operatively connected to said sensor.
Claim 10
Dependent Claim
15 words
In combination, a pressure operated apparatus and the liquid level operated sensor of claim 7.
Claim 11
Dependent Claim
54 words
In a method of operating an apparatus for liquid removal or dispensing into containers by altering the pressure in the apparatus, the improvement which comprises connecting the liquid level operated sensor of claim 7 to said apparatus and adjusting the pressure within the apparatus in response to the output signal of the resistivity sensor.
Claim 12
Dependent Claim
20 words
The method of claim 10 in which the pressure adjustment is in response to the presence of the output signal.
Claim 13
Dependent Claim
20 words
The method of claim 10 in which the pressure adjustment is in response to the magnitude of the output signal.
Claim 14
Dependent Claim
13 words
The sensor of claim 1 wherein said U-shaped container is a U-shaped tube.
Claim 15
Dependent Claim
63 words
The sensor of claim 13 wherein said means to connect is an electrically operated valve and further comprising means to cause the resistivity sensor to generate an output signal when in contact with said conductive fluid and means to control both the pressure in the apparatus and the valve in response to the output signal of the sensor operatively connected to the sensor.
Claim 16
Dependent Claim
15 words
In combination, a pressure operated apparatus and the liquid level operated sensor of claim 14.
Claim 17
Dependent Claim
15 words
In combination, a pressure operated apparatus and the liquid level operated sensor of claim 1.
Claim 18
Dependent Claim
15 words
The combination of claim 16 wherein said pressure operated apparatus comprises a pressure operated pipet.
Claim 19
Dependent Claim
54 words
In a method of operating an apparatus for liquid removal or dispensing into containers by altering the pressure in the apparatus, the improvement which comprises connecting the liquid level operated sensor of claim 1 to said apparatus and adjusting the pressure within the apparatus in response to the output signal of the resistivity sensor.
Claim 20
Dependent Claim
20 words
The method of claim 18 in which the pressure adjustment is in response to the presence of the output signal.
Claim 21
Dependent Claim
20 words
The method of claim 18 in which the pressure adjustment is in response to the magnitude of the output signal.
References Cited (Backward Citations)
US2423397A
Cited
GB844010A
Cited
FR1342284A
Cited
US3477460A
Cited
US3687289A
Cited
US3813945A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-10-18 | 1992-04-18 | 1992-10-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-10-18 | 1996-04-18 | 1996-10-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-10-18 | 2000-04-18 | 2000-10-18 | $7700.00 | Window Closed / Lapsed |