US3225256A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical protection systems
Assignee: English Electric Co Ltd
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Filing: 1962-06-18
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Granted: 1965-12-21
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Expires: 1982-06-18
Abstract
No abstract record available.
Inventors
- 👤 Carter Ronald Philip
- 👤 Cowin William Alan
- 👤 Hall Martin Clifford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 11:37
CPC Classifications
H; H02; H02H; H02H3/00; H02H3/26; H02H3/28; H02H3/30; H02H3/307; H02H3/302; H03; H03K; H03K5/00; H03K5/01; H03K5/08
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
185 words
AN ELECTRICAL PROTECTION SYSTEM FOR PROTECTING A SECTION OF POLYPHASE ALTERNATING CURRENT POWER SUPPLY LINE, COMPRISING EQUIPMENT FOR CONNECTION TO ONE END OF THE SAID SECTION OF LINE, SIMILAR EQUIPMENT FOR CONNECTION TO THE OTHER END OF THE SAID SECTION OF LINE, MEANS FOR INTERCONNECTING THE TWO EQUIPMENTS, THE SAID EQUIPMENT INCLUDING MEANS FOR GENERATING A CARRIER WAVE, MODULATING MEANS FOR CYCLICALLY MODULATING THE AMPLITUDE OF THE SAID CARRIER WAVE BY A MODULATING SIGNAL DERIVED FROM THE CURRENT IN THE SAID ONE END OF THE SECTION, PHASE COMPARING MEANS FOR PHASE COMPARING THE SAID MODULATED CARRIER WAVE WITH A CORRESPONDING MODULATED CARRIER WAVE RECEIVED FROM THE SAID SIMILAR EQUIPMENT AND FOR GENERATING PULSES WHOSE LENGTHS ARE DEPENDENT ON THE EXTENT OF THE INSTANTANEOUS DISPLACEMENT, IF ANY, FROM THE NORMAL PHASE RELATIONSHIP BETWEEN THE TWO COMPARED MODULATED CARRIER WAVES, SUCH DISPLACEMENT INDICTING THE PRESENCE OF A FAULT ON THE LINE, MEASURING MEANS FOR MEASURING THE LENGTH OF EACH SAID PULSE AND MEANS ADAPTED TO PERFORM A PROTECTIVE FUNCTION WHEN THE LENGTH OF A PULSE EXCEEDS A PREDETERMINED MINIMUM LENGTH INDICTIVE OF A PREDETERMINED MINIMUM PHASE DISPLACEMENT.
Claim 2
Dependent Claim
185 words
AN ELECTRICAL PROTECTION SYSTEM FOR PROTECTING A SECTION OF POLYPHASE ALTERNATING CURRENT POWER SUPPLY LINE, COMPRISING EQUIPMENT FOR CONNECTION TO ONE END OF THE SAID SECTION OF LINE, SIMILAR EQUIPMENT FOR CONNECTION TO THE OTHER END OF THE SAID SECTION OF LINE, MEANS FOR INTERCONNECTING THE TWO EQUIPMENTS, THE SAID EQUIPMENT INCLUDING MEANS FOR GENERATING A CARRIER WAVE, MODULATING MEANS FOR CYCLICALLY MODULATING THE AMPLITUDE OF THE SAID CARRIER WAVE BY A MODULATING SIGNAL DERIVED FROM THE CURRENT IN THE SAID ONE END OF THE SECTION, PHASE COMPARING MEANS FOR PHASE COMPARING THE SAID MODULATED CARRIER WAVE WITH A CORRESPONDING MODULATED CARRIER WAVE RECEIVED FROM THE SAID SIMILAR EQUIPMENT AND FOR GENERATING PULSES WHOSE LENGTHS ARE DEPENDENT ON THE EXTENT OF THE INSTANTANEOUS DISPLACEMENT, IF ANY, FROM THE NORMAL PHASE RELATIONSHIP BETWEEN THE TWO COMPARED MODULATED CARRIER WAVES, SUCH DISPLACEMENT INDICTING THE PRESENCE OF A FAULT ON THE LINE, MEASURING MEANS FOR MEASURING THE LENGTH OF EACH SAID PULSE AND MEANS ADAPTED TO PERFORM A PROTECTIVE FUNCTION WHEN THE LENGTH OF A PULSE EXCEEDS A PREDETERMINED MINIMUM LENGTH INDICTIVE OF A PREDETERMINED MINIMUM PHASE DISPLACEMENT.
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) | 1968-12-20 | 1969-06-21 | 1969-12-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-12-20 | 1973-06-21 | 1973-12-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-12-20 | 1977-06-21 | 1977-12-21 | $7700.00 | Window Closed / Lapsed |