Patent US3555412A successfully refreshed from Google Patents.
US3555412A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Probe for detection of surface cracks in metals utilizing a hall probe
Assignee: United States Department of the Army
•
Filing: 1968-11-26
•
Granted: 1971-01-12
•
Expires: 1988-11-26
Abstract
Abstract A HALL EFFECT DETECTOR IS MOUNTED BETWEEN A PAIR OF ELECTRODES. THE ELECTRODES ARE MOVED ALONG A CURRENT CONDUCTING SURFACE HAVING A CRACK, OR SUSPECTED OF HAVING A CRACK OR OTHER FLAW. THE CRACK ALTERS THE FLOW OF CURRENT AND CHANNELS IT BETWEEN THE ELECTRODES THEREBY INCREASING THE MAGNETIC FIELD IN THE AREA OF THE CRACK. THE MAGNITUDE OF THE INCREASE OF THE MAGNETIC FIELD INDICATES THE SIZE OF THE CRACK OR FLAW. THE DIRECTION OF THE CRACK ALSO AFFECTS THE MAGNITUDE OF THE CHANGE. THEREFORE, THE DIRECTION OF THE CRACK, AS WELL AS ITS DEPTH AND LENGTH, CAN BE ASCERTAINED BY PROBING WITH THE PRESENT INSTRUMENT, AS TAUGHT HEREIN.
Inventors
- 👤 Kenneth A Fowler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:31
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/72; G01N27/82; G01N27/83
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-01-11 | 1974-07-13 | 1975-01-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-11 | 1978-07-13 | 1979-01-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-11 | 1982-07-13 | 1983-01-12 | $7700.00 | Window Closed / Lapsed |