US3159784A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Eddy current testing apparatus having means to relate electrical characteristics of a pickup unit to physical properties of a speciment
Assignee: Kelvin Hughes Ltd
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Filing: 1960-12-14
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Granted: 1964-12-01
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Expires: 1980-12-14
Abstract
No abstract record available.
Inventors
- 👤 Haslett Roy William George
- 👤 Freeman Eric Lionel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:38
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/72; G01N27/82; G01N27/90; G01N27/9046
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
156 words
APPARATUS FOR THE ELECTROMAGNETIC TESTING OF MATERIALS INCLUDING A TEST COIL WITHIN WHICH THE SPECIMEN TO BE TESTED CAN BE LOCATED, MEANS FOR ESTABLISHING IN THE TEST COIL IN RESPONSE TO A TEST SIGNAL APPLIED TO THE COIL AN ALTERNATING CURRENT INVERSELY PROPORTIONAL TO THE FREQUENCY OF THE TEST SIGNAL, AND MEANS FOR DERIVING FROM THE COIL AND APPLYING TO DEFLECT THE ELECTRON BEAM OF A CATHODE RAY TUBE IN MUTUALLY PERPENDICULAR DIRECTIONS A SIGNAL PROPORTIONAL TO THE INDUCTIVE COMPONENT OF THE IMPEDANCE OF THE TEST COIL AND A SIGNAL PROPORTIONAL TO THE RATIO OF THE CHANGE IN THE RESISTIVE COMPONENT OF THE IMPEDANCE OF THE TEST COIL TO THE SAID FREQUENCY, IN WHICH THE SAID MEANS FOR ESTABLISHING AN ALTERNATING CURRENT IN THE TEST COIL COMPRISES A VARIABLE-FREQUENCY OSCILLATION GENERATOR CONNECTED ACROSS THE SERIES COMBINATION OF A RESISTOR AND A CAPACITOR, THE RESISTANCE OF THE RESISTOR BEING MUCH GREATER THAN THE REACTANCE OF THE CAPACITOR
Claim 2
Dependent Claim
156 words
APPARATUS FOR THE ELECTROMAGNETIC TESTING OF MATERIALS INCLUDING A TEST COIL WITHIN WHICH THE SPECIMEN TO BE TESTED CAN BE LOCATED, MEANS FOR ESTABLISHING IN THE TEST COIL IN RESPONSE TO A TEST SIGNAL APPLIED TO THE COIL AN ALTERNATING CURRENT INVERSELY PROPORTIONAL TO THE FREQUENCY OF THE TEST SIGNAL, AND MEANS FOR DERIVING FROM THE COIL AND APPLYING TO DEFLECT THE ELECTRON BEAM OF A CATHODE RAY TUBE IN MUTUALLY PERPENDICULAR DIRECTIONS A SIGNAL PROPORTIONAL TO THE INDUCTIVE COMPONENT OF THE IMPEDANCE OF THE TEST COIL AND A SIGNAL PROPORTIONAL TO THE RATIO OF THE CHANGE IN THE RESISTIVE COMPONENT OF THE IMPEDANCE OF THE TEST COIL TO THE SAID FREQUENCY, IN WHICH THE SAID MEANS FOR ESTABLISHING AN ALTERNATING CURRENT IN THE TEST COIL COMPRISES A VARIABLE-FREQUENCY OSCILLATION GENERATOR CONNECTED ACROSS THE SERIES COMBINATION OF A RESISTOR AND A CAPACITOR, THE RESISTANCE OF THE RESISTOR BEING MUCH GREATER THAN THE REACTANCE OF THE CAPACITOR
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) | 1967-12-01 | 1968-06-01 | 1968-12-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1971-12-01 | 1972-06-01 | 1972-12-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1975-12-01 | 1976-06-01 | 1976-12-01 | $7700.00 | Window Closed / Lapsed |