US3218522A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Demagnetizing apparatus
Assignee: Individual
•
Filing: 1961-05-15
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Granted: 1965-11-16
•
Expires: 1981-05-15
Abstract
No abstract record available.
Inventors
- 👤 Arthur K Littwin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 13:02
CPC Classifications
H; H01; H01F; H01F13/00; H01F13/006
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
107 words
APPARATUS FOR DEMAGNETIZING AN OBJECT, COMPRISING A D.C. CIRCUIT INCLUDING THE OBJECT TO BE DEMAGNETIZED, MEANS FOR IMPRESSING DIRECT CURRENT ON THE OBJECT, SWITCH MEANS FOR INTERRUPTING THE DIRECT CURRENT AND REVERSING THE POLARITY THEREOF AT EACH INTERRUPTION, MEANS FOR PROGRESSIVELY REDUCING THE VOLTAGE OF THE DIRECT CURRENT IN THE D.C. CIRCUIT, DRIVING MEANS FOR SIMULTANEOUSLY OPERATING THE SWITCH MEANS AND VOLTAGE REDUCING MEANS, CONTROL MEANS FOR INITIATING AND TERMINATING OPERATION OF THE DRIVING MEANS AND THEREBY PREDETERMINING A DEMAGNETIZING CYCLE OF OPERATION, AND MEANS FOR ADJUSTABLY VARYING THE RATE OF OPERATION OF EITHER OF THE SWITCH MEANS OR THE VOLTAGE REDUCING MEANS INDEPENDENTLY OF THE OTHER.
Claim 2
Dependent Claim
107 words
APPARATUS FOR DEMAGNETIZING AN OBJECT, COMPRISING A D.C. CIRCUIT INCLUDING THE OBJECT TO BE DEMAGNETIZED, MEANS FOR IMPRESSING DIRECT CURRENT ON THE OBJECT, SWITCH MEANS FOR INTERRUPTING THE DIRECT CURRENT AND REVERSING THE POLARITY THEREOF AT EACH INTERRUPTION, MEANS FOR PROGRESSIVELY REDUCING THE VOLTAGE OF THE DIRECT CURRENT IN THE D.C. CIRCUIT, DRIVING MEANS FOR SIMULTANEOUSLY OPERATING THE SWITCH MEANS AND VOLTAGE REDUCING MEANS, CONTROL MEANS FOR INITIATING AND TERMINATING OPERATION OF THE DRIVING MEANS AND THEREBY PREDETERMINING A DEMAGNETIZING CYCLE OF OPERATION, AND MEANS FOR ADJUSTABLY VARYING THE RATE OF OPERATION OF EITHER OF THE SWITCH MEANS OR THE VOLTAGE REDUCING MEANS INDEPENDENTLY OF THE OTHER.
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) | 1968-11-15 | 1969-05-17 | 1969-11-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-11-15 | 1973-05-17 | 1973-11-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-11-15 | 1977-05-17 | 1977-11-16 | $7700.00 | Window Closed / Lapsed |