US3667500A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid level controller
Assignee: Richardson Co
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Filing: 1969-12-11
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Granted: 1972-06-06
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Expires: 1989-12-11
Abstract
Abstract An apparatus for controlling liquid levels for viscous liquids such as printing ink utilizing pneumatic probes and responsive liquid regulating means.
Inventors
- 👤 Leslie F Stone
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:22
CPC Classifications
G; G05; G05D; G05D9/00; G05D9/04; Y; Y10; Y10T; Y10T137/00; Y10T137/7287
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
254 words
An apparatus for controlling the level of liquids in vessels which includes a first pneumatic probe extending into the liquid to a predetermined high level and communicating with liquid regulating means in combination with an air pressure supply disposed outside the vessel charging air through the probe and into the liquid, the probe being opened when the liquid level is below the high level to actuate the liquid regulating means to add liquid to the vessel and the probe being closed by the liquid when the liquid level is above the high level to actuate the liquid regulating means to stop the addition of liquid to the vessel, said apparatus including a second pneumatic probe extending into the liquid to a predetermined low level and communicating with alarm and control means in combination with an air pressure supply disposed outside the vessel charging air through the probe and into the liquid, the second probe being closed by the liquid when the liquid level is above the low level and the probe being opened when the liquid level is below the low level to actuate the alarm and control means, said alarm and control means being electrically operated and including a pressure-sensitive switch communicating with the second probe, such switch being actuated to close by a low pressure condition within the probe when the liquid level is below the low level and such switch being actuated to open by a high pressure condition within the probe when the liquid level is above the low level.
Claim 2
Independent Claim
254 words
An apparatus for controlling the level of liquids in vessels which includes a first pneumatic probe extending into the liquid to a predetermined high level and communicating with liquid regulating means in combination with an air pressure supply disposed outside the vessel charging air through the probe and into the liquid, the probe being opened when the liquid level is below the high level to actuate the liquid regulating means to add liquid to the vessel and the probe being closed by the liquid when the liquid level is above the high level to actuate the liquid regulating means to stop the addition of liquid to the vessel, said apparatus including a second pneumatic probe extending into the liquid to a predetermined low level and communicating with alarm and control means in combination with an air pressure supply disposed outside the vessel charging air through the probe and into the liquid, the second probe being closed by the liquid when the liquid level is above the low level and the probe being opened when the liquid level is below the low level to actuate the alarm and control means, said alarm and control means being electrically operated and including a pressure-sensitive switch communicating with the second probe, such switch being actuated to close by a low pressure condition within the probe when the liquid level is below the low level and such switch being actuated to open by a high pressure condition within the probe when the liquid level is above the low level.
Claim 3
Dependent Claim
78 words
The apparatus of claim 1 wherein the pressure sensitive switch is in series with an alarm and a relay, such relay having contacts in series with motor means, and normally being closed to complete an energizing circuit to such motor means whereby a circuit is completed when the pressure sensitive switch is closed to actuate the alarm and energize the relay thereby opening its contacts and interrupting the circuit to the motor means to deenergize such motor means.
Claim 4
Dependent Claim
25 words
The apparatus of claim 2 wherein the relay is a time delay relay which upon being energized delays for a period before opening its contacts.
Claim 5
Dependent Claim
69 words
The apparatus of claim 1 wherein the liquid regulating means are electrically operated and include a pressure sensitive switch communicating with the probe, such switch being actuated to close by a low pressure condition within the probe when the liquid level is below the high level and such switch being actuated to open by a high pressure condition within the probe when the liquid is above the high level.
Claim 6
Dependent Claim
58 words
The apparatus of claim 4 wherein the pressure sensitive switch is in series with a solenoid controlling a valve for adding liquid, such solenoid being energized when the switch is closed to open the valve thereby adding liquid and such solenoid being deenergized when the switch is open to close the valve and stop the addition of liquid.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-06 | 1975-12-06 | 1976-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-06 | 1979-12-06 | 1980-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-06 | 1983-12-06 | 1984-06-06 | $7700.00 | Window Closed / Lapsed |