US3242064A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cathodic protection system
Assignee: Engelhard Industries Inc
•
Filing: 1961-01-26
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Granted: 1966-03-22
•
Expires: 1981-01-26
Abstract
No abstract record available.
Inventors
- 👤 Paul B Byrne
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:12
CPC Classifications
C; C23; C23F; C23F13/00; C23F13/02; C23F13/04
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
172 words
A SYSTEM FOR CATHODIC PROTECTION OF A SURFACE COMPRISING AN ANODE INSULATED FROM THE SURFACE, A SOURCE OF ELECTRIC POWER, A TRANSISTOR CONNECTED TO THE SOURCE OF POWER AND TO THE ANODE TO PASS CURRENT TO THE ANODE IN THE FORM OF PULSES AS THE TRANSISTOR IS INTERMITTENTLY SWITCHED BETWEEN ITS CONDUCTIVE AND NON-CONDUCTIVE STATES, A SENSING HALF-CELL INSULATED FROM SAID SURFACE, AND ELECTRIC CIRCUIT MEANS CONNECTED BETWEEN THE SENSING HALF-CELL AND THE TRANSISTOR TO SWITCH THE TRANSISTOR TO ITS CONDUCTIVE STATE AND TO VARY THE RATIO OF THE DURATION OF THE PULSES TO THE TIME BETWEEN IN PROPORTION TO THE RESPONSE OF THE HALF-CELL WHEN THE NEGATIVE POTENTIAL OF SAID SURFACE DECREASES TO A FIRST PREDETERMINED LEVEL RELATIVE TO THE POTENTIAL OF THE SENSING HALF-CELL AND TO SWITCH THE TRANSISTOR TO ITS NON-CONDUCTIVE STATE WHEN THE NEGATIVE POTENTIAL OF THE SURFACE INCREASES TO A SECOND PREDETERMINED LEVEL RELATIVE TO THE POTENTIAL OF THE HALF-CELL, THE NEGATIVE POTENTIAL OF SAID SECOND LEVEL BEING GREATER THAT THE NEGATIVE POTENTIAL OF SAID FIRST LEVEL.
Claim 2
Independent Claim
172 words
A SYSTEM FOR CATHODIC PROTECTION OF A SURFACE COMPRISING AN ANODE INSULATED FROM THE SURFACE, A SOURCE OF ELECTRIC POWER, A TRANSISTOR CONNECTED TO THE SOURCE OF POWER AND TO THE ANODE TO PASS CURRENT TO THE ANODE IN THE FORM OF PULSES AS THE TRANSISTOR IS INTERMITTENTLY SWITCHED BETWEEN ITS CONDUCTIVE AND NON-CONDUCTIVE STATES, A SENSING HALF-CELL INSULATED FROM SAID SURFACE, AND ELECTRIC CIRCUIT MEANS CONNECTED BETWEEN THE SENSING HALF-CELL AND THE TRANSISTOR TO SWITCH THE TRANSISTOR TO ITS CONDUCTIVE STATE AND TO VARY THE RATIO OF THE DURATION OF THE PULSES TO THE TIME BETWEEN IN PROPORTION TO THE RESPONSE OF THE HALF-CELL WHEN THE NEGATIVE POTENTIAL OF SAID SURFACE DECREASES TO A FIRST PREDETERMINED LEVEL RELATIVE TO THE POTENTIAL OF THE SENSING HALF-CELL AND TO SWITCH THE TRANSISTOR TO ITS NON-CONDUCTIVE STATE WHEN THE NEGATIVE POTENTIAL OF THE SURFACE INCREASES TO A SECOND PREDETERMINED LEVEL RELATIVE TO THE POTENTIAL OF THE HALF-CELL, THE NEGATIVE POTENTIAL OF SAID SECOND LEVEL BEING GREATER THAT THE NEGATIVE POTENTIAL OF SAID FIRST LEVEL.
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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) | 1969-03-21 | 1969-09-20 | 1970-03-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-03-21 | 1973-09-20 | 1974-03-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-03-21 | 1977-09-20 | 1978-03-22 | $7700.00 | Window Closed / Lapsed |