US3341888A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic control system and method
Assignee: Dow Chemical Co
•
Filing: 1963-04-18
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Granted: 1967-09-19
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Expires: 1983-04-18
Abstract
No abstract record available.
Inventors
- 👤 William A Bridge
- 👤 Donald J Crawford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:24
CPC Classifications
G; G05; G05D; G05D9/00; G05D9/12; B; B29; B29C; B29C48/00; B29C48/25; B29C48/92; B29C2948/00; B29C2948/92; B29C2948/92009; B29C2948/92085; B29C2948/92095; B29C2948/92114; B29C2948/92133; B29C2948/92504; B29C2948/92609; B29C2948/92628; B29C2948/92819; B29C2948/92923; B29C48/03; B29C48/09; B29C48/10
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
132 words
FOR USE IN AN AUTOMATIC CONTROL SYSTEM WHEREIN A PROCESS VARIABLE IS TO BE MAINTAINED WITHIN A PREDETERMINED RANGE, WHICH SYSTEM INCLUDES SENSOR MEANS FOR MONITORING AND MEASURING CHANGES IN SAID PROCESS VARIABLE AND GENERATING AN ERROR SIGNAL INDICATIVE OF A CHANGE IN SAID PROCESS VARIABLE FROM A PRESET VALUE, AN ELECTRICAL CIRCUIT COMPRISING INTEGRATING MEANS INCLUDING A RESISTOR AND A CAPACITOR FOR INTEGRATING SAID ERROR SIGNAL TO GENERATE A CONTROL SIGNAL; MEANS COUPLED TO SAID INTEGRATING MEANS FOR PROVIDING A FEEDBACK VOLTAGE THERETO OF A POLARITY SUCH THAT SAID CONTROL SIGNAL HAS AN ON-TIME WHICH IS LINEARLY PROPORTIONAL TO THE INTEGRATED VALUE OF SAID ERROR SIGNAL; AND CONTROL MEANS OPERATED IN RESPONSE TO SAID CONTROL SIGNAL TO INFLUENCE THE PROCESS SO THAT THE PROCES VARIABLE IS RETURNED TO SAID PRESET VALUE.
Claim 2
Dependent Claim
132 words
FOR USE IN AN AUTOMATIC CONTROL SYSTEM WHEREIN A PROCESS VARIABLE IS TO BE MAINTAINED WITHIN A PREDETERMINED RANGE, WHICH SYSTEM INCLUDES SENSOR MEANS FOR MONITORING AND MEASURING CHANGES IN SAID PROCESS VARIABLE AND GENERATING AN ERROR SIGNAL INDICATIVE OF A CHANGE IN SAID PROCESS VARIABLE FROM A PRESET VALUE, AN ELECTRICAL CIRCUIT COMPRISING INTEGRATING MEANS INCLUDING A RESISTOR AND A CAPACITOR FOR INTEGRATING SAID ERROR SIGNAL TO GENERATE A CONTROL SIGNAL; MEANS COUPLED TO SAID INTEGRATING MEANS FOR PROVIDING A FEEDBACK VOLTAGE THERETO OF A POLARITY SUCH THAT SAID CONTROL SIGNAL HAS AN ON-TIME WHICH IS LINEARLY PROPORTIONAL TO THE INTEGRATED VALUE OF SAID ERROR SIGNAL; AND CONTROL MEANS OPERATED IN RESPONSE TO SAID CONTROL SIGNAL TO INFLUENCE THE PROCESS SO THAT THE PROCES VARIABLE IS RETURNED TO SAID PRESET VALUE.
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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) | 1970-09-18 | 1971-03-20 | 1971-09-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-09-18 | 1975-03-20 | 1975-09-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-09-18 | 1979-03-20 | 1979-09-19 | $7700.00 | Window Closed / Lapsed |