US3131335A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid level controller
Assignee: Individual
•
Filing: 1960-11-10
•
Granted: 1964-04-28
•
Expires: 1980-11-10
Abstract
No abstract record available.
Inventors
- 👤 Carl O Berglund
- 👤 Roy R Thompson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:33
CPC Classifications
G; G01; G01F; G01F23/00; G01F23/22; G01F23/24; G01F23/241; G05; G05D; G05D9/00; G05D9/12; Y; Y10; Y10T; Y10T137/00; Y10T137/7287; Y10T137/7306
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
140 words
A SYSTEM FOR OPENING AND CLOSING THE SWITCH OF A RELAY IN RESPONSE TO VARIATIONS BETWEEN A PREDETERMINED UPPER LEVEL AND A PREDETERMINED LOWER LEVEL OF AN ELECTROLYTE TEMPORARILY STORED IN A VESSEL, COMPRISING: A FIRST CONTACT SUPPORTED IN THE VESSEL AT SAID PREDETERMINED UPPER LEVEL AND CONNECTED TO ONE END OF THE COIL OF THE RELAY, A PNP-TYPE TRANSISTOR HAVING ITS COLLECTOR CONNECTED TO THE OPPOSITE END OF SAID RELAY COIL, MEANS FOR SUPPLYING A POSITIVE D.C. CURRENT TO THE EMITTER OF SAID TRANSISTOR, A SECOND CONTACT SUPPORTED IN THE VESSEL AT SAID PREDETERMINED LOWER LEVEL AND CONNECTED TO THE BASE OF SAID TRANSISTOR FOR PLACING A NEGATIVE BIAS ON SAID BASE AND RENDERING SAID TRANSISTOR CONDUCTIVE WHEN BOTH OF SAID FIRST AND SECOND CONTACTS ARE IMMERSED IN THE ELECTROLYTE TO IN TURN CLOSE SAID RELAY, A THIRD CON-
Claim 2
Independent Claim
140 words
A SYSTEM FOR OPENING AND CLOSING THE SWITCH OF A RELAY IN RESPONSE TO VARIATIONS BETWEEN A PREDETERMINED UPPER LEVEL AND A PREDETERMINED LOWER LEVEL OF AN ELECTROLYTE TEMPORARILY STORED IN A VESSEL, COMPRISING: A FIRST CONTACT SUPPORTED IN THE VESSEL AT SAID PREDETERMINED UPPER LEVEL AND CONNECTED TO ONE END OF THE COIL OF THE RELAY, A PNP-TYPE TRANSISTOR HAVING ITS COLLECTOR CONNECTED TO THE OPPOSITE END OF SAID RELAY COIL, MEANS FOR SUPPLYING A POSITIVE D.C. CURRENT TO THE EMITTER OF SAID TRANSISTOR, A SECOND CONTACT SUPPORTED IN THE VESSEL AT SAID PREDETERMINED LOWER LEVEL AND CONNECTED TO THE BASE OF SAID TRANSISTOR FOR PLACING A NEGATIVE BIAS ON SAID BASE AND RENDERING SAID TRANSISTOR CONDUCTIVE WHEN BOTH OF SAID FIRST AND SECOND CONTACTS ARE IMMERSED IN THE ELECTROLYTE TO IN TURN CLOSE SAID RELAY, A THIRD CON-
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) | 1967-04-28 | 1967-10-28 | 1968-04-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1971-04-28 | 1971-10-28 | 1972-04-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1975-04-28 | 1975-10-28 | 1976-04-28 | $7700.00 | Window Closed / Lapsed |