US3239741A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control system for a.c. motors
Assignee: Loewe Opta GmbH
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Filing: 1962-12-03
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Granted: 1966-03-08
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Expires: 1982-12-03
Abstract
No abstract record available.
Inventors
- 👤 Rank Wolfgang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:50
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/76; H04N5/78; H04N5/782; H02; H02P; H02P23/00; H02P23/18; H02P23/186; H02P7/00; H02P7/06; H02P7/18; H02P7/24; H02P7/28; H02P7/2805
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
139 words
IN A SYSTEM FOR RECORDING AND REPRODUCING VIDEO SIGNALS ON A MAGNETIC TAPE BY USING A MOTOR-DRIVEN ROTATING HEAD, THE SPEED OF SAID MOTOR BEING CONTROLLED BY TELEVISION SYNCHRONISING SIGNALS, THE METHOD FOR PRODUCING A PREDETERMINED PHASE SYCHRONISM OF THE ROTOR SPEED OF AN UNPOLARISED SYNCHRONOUS MOTOR TOGETHER THE WITH THE A.C. MOTOR-VOLTAGE ONLY AFTER STARTING THE MOTOR CONSISTING IN TRANSFORMING THE MOTOR VOLTAGE BY MEANS OF AN ISOLATING TRANSFORMER, IN RECTIFYING THE TRANSFORMED VOLTAGE BY MEANS OF A HALF-WAVE RECTIFIER, IN SUPPLYING A SUBSEQUENT PHOTOCELL WITH SAID RECTIFIED VOLTAGE, IN SHORTLY ILLUMINATING SAID PHOTOCELL ONCE PER REVOLUTION OF THE ROTOR, IN PRODUCING A PHOTOELECTRIC CURRENT BY SAID PHOTOCELL ONLY IN CASE OF PHASE SYNCHRONISM, AND IN ENERGIZING AN ELECTRICAL RELAY BY SAID PHOTOELECTRIC CURRENT, A CONTACT OF SAID RELAY BRIDGING A LOAD RESISTANCE IN THE MOTOR SUPPLY CIRCUIT.
Claim 2
Dependent Claim
139 words
IN A SYSTEM FOR RECORDING AND REPRODUCING VIDEO SIGNALS ON A MAGNETIC TAPE BY USING A MOTOR-DRIVEN ROTATING HEAD, THE SPEED OF SAID MOTOR BEING CONTROLLED BY TELEVISION SYNCHRONISING SIGNALS, THE METHOD FOR PRODUCING A PREDETERMINED PHASE SYCHRONISM OF THE ROTOR SPEED OF AN UNPOLARISED SYNCHRONOUS MOTOR TOGETHER THE WITH THE A.C. MOTOR-VOLTAGE ONLY AFTER STARTING THE MOTOR CONSISTING IN TRANSFORMING THE MOTOR VOLTAGE BY MEANS OF AN ISOLATING TRANSFORMER, IN RECTIFYING THE TRANSFORMED VOLTAGE BY MEANS OF A HALF-WAVE RECTIFIER, IN SUPPLYING A SUBSEQUENT PHOTOCELL WITH SAID RECTIFIED VOLTAGE, IN SHORTLY ILLUMINATING SAID PHOTOCELL ONCE PER REVOLUTION OF THE ROTOR, IN PRODUCING A PHOTOELECTRIC CURRENT BY SAID PHOTOCELL ONLY IN CASE OF PHASE SYNCHRONISM, AND IN ENERGIZING AN ELECTRICAL RELAY BY SAID PHOTOELECTRIC CURRENT, A CONTACT OF SAID RELAY BRIDGING A LOAD RESISTANCE IN THE MOTOR SUPPLY CIRCUIT.
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) | 1969-03-07 | 1969-09-06 | 1970-03-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-03-07 | 1973-09-06 | 1974-03-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-03-07 | 1977-09-06 | 1978-03-08 | $7700.00 | Window Closed / Lapsed |