US3087440A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control circuit
Assignee: Wisconsin Alumni Research Foundation
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Filing: 1960-05-12
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Granted: 1963-04-30
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Expires: 1980-05-12
Abstract
No abstract record available.
Inventors
- 👤 William C Zarnstorff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 23:49
CPC Classifications
A; A63; A63H; A63H19/00; A63H19/24; G; G08; G08G; G08G1/00; G08G1/07; G08G1/081; G08G1/082; G08G1/085
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
128 words
A CIRCUIT FOR CONTROLLING THE SUPPLY OF ELECTRIC POWER TO AN ELECTRIC MOTOR ADAPTED TO DRIVE A TRAIN ON AN ELECTRICALLY CONDUCTIVE TRACK, THE CIRCUIT COMPRISING A SOURCE OF OPERATING VOLTAGE, MEANS CONNECTING THE OPERATING VOLTAGE TO THE TRACK, MEANS CONNECTING THE MOTOR TO THE TRACK, A VARIABLE IMPEDANCE, MEANS CONNECTING THE IMPEDANCE TO CONTROL THE FLOW OF ELECTRIC POWER THROUGH THE MOTOR, A SOURCE OF CONTROL VOLTAGE OF A FREQUENCY DIFFERENT FROM THAT OF THE OPERATING VOLTAGE, MEANS FOR SUPERIMPOSING THE CONTROL VOLTAGE ON THE OPERATING VOLTAGE ON THE TRACK, MEANS FOR CHANGING THE AMPLITUDE OF THE CONTROL VOLTAGE AND MEANS SELECTIVELY RESPONSIVE TO THE AMPLITUDE OF THE CONTROL VOLTAGE FOR CHANGING THE IMPEDANCE OF THE VARIABLE IMPEDANCE AND THEREBY CONTROL THE POWER FLOWING THROUGH THE MOTOR.
References Cited (Backward Citations)
US2622542A
Cited
US2743678A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1966-04-29 | 1966-10-29 | 1967-04-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1970-04-29 | 1970-10-29 | 1971-04-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1974-04-29 | 1974-10-29 | 1975-04-30 | $7700.00 | Window Closed / Lapsed |