US2720488A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of increasing emissivity of tantalum
Assignee: Lane Wells Co
•
Filing: 1953-03-02
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Granted: 1955-10-11
•
Expires: 1973-03-02
Abstract
No abstract record available.
Inventors
- 👤 Robert J Dwyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 13:14
CPC Classifications
C; C25; C25D; C25D11/00; C25D11/02; C25D11/26
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
170 words
A METHOD OF INCREASING THE THERMAL EMISSIVITY OF A SURFACE OF TANTALUM COMPRISING: IMMERSING AND SUBJECTING THE SAID SURFACE OF TANTALUM TO TREATMENT AS THE ANODE IN AN AQUEOUS SOLUTION OF SODIUM HYDROXIDE HAVING A CONCENTRATION OF AT LEAST APPROXIMATELY 2 1/2 NORMAL, SAID TREATMENT COMPRISING APPLYING A POTENTIAL DIFFERENCE BETWEEN THE TANTALUM SURFACE AND SAID SOLUTION FOR A TIME SUFFICIENT TO FORM AN INITIAL, COLORED, HIGH RESISTANCE COATING ON SAID SURFACE; THEREUPON INCREASING THE CURRENT UNTIL A SUBSTANTIALLY CONTINUOUS, CREEPING ELECTRIC SPARK APPEARS ON SAID INITIALLY COATED SURFACE IMMERSED IN SAID SOLUTION, THE CURRENT FLOW THROUGH SAID SPARK BEING SUBSTANTIALLY INDEPENDENT OF THE AREA OF SAID IMMERSED SURFACE OF TANTALUM, AND SAID SPARK MAINTAINING A SUBSTANTIALLY CONSTANT VOLTAGE THEREACROSS WITH INCREASING CURRENT THERETHROUGH; AND MAINTAINING SAID SPARK UNTIL THE SPARK HAS CREPT OVER THE PORTION OF THE AREA OF THE IMMERSED PORTION OF THE TANTALUM WHICH IS TO HAVE ITS THERMAL EMISSIVITY INCREASED AND SUCH PORTION OF THE SURFACE HAS CHANGED TO A DULL GRAYISH TO GRAYISH LAVENDER COLOR.
Claim 2
Independent Claim
170 words
A METHOD OF INCREASING THE THERMAL EMISSIVITY OF A SURFACE OF TANTALUM COMPRISING: IMMERSING AND SUBJECTING THE SAID SURFACE OF TANTALUM TO TREATMENT AS THE ANODE IN AN AQUEOUS SOLUTION OF SODIUM HYDROXIDE HAVING A CONCENTRATION OF AT LEAST APPROXIMATELY 2 1/2 NORMAL, SAID TREATMENT COMPRISING APPLYING A POTENTIAL DIFFERENCE BETWEEN THE TANTALUM SURFACE AND SAID SOLUTION FOR A TIME SUFFICIENT TO FORM AN INITIAL, COLORED, HIGH RESISTANCE COATING ON SAID SURFACE; THEREUPON INCREASING THE CURRENT UNTIL A SUBSTANTIALLY CONTINUOUS, CREEPING ELECTRIC SPARK APPEARS ON SAID INITIALLY COATED SURFACE IMMERSED IN SAID SOLUTION, THE CURRENT FLOW THROUGH SAID SPARK BEING SUBSTANTIALLY INDEPENDENT OF THE AREA OF SAID IMMERSED SURFACE OF TANTALUM, AND SAID SPARK MAINTAINING A SUBSTANTIALLY CONSTANT VOLTAGE THEREACROSS WITH INCREASING CURRENT THERETHROUGH; AND MAINTAINING SAID SPARK UNTIL THE SPARK HAS CREPT OVER THE PORTION OF THE AREA OF THE IMMERSED PORTION OF THE TANTALUM WHICH IS TO HAVE ITS THERMAL EMISSIVITY INCREASED AND SUCH PORTION OF THE SURFACE HAS CHANGED TO A DULL GRAYISH TO GRAYISH LAVENDER COLOR.
References Cited (Backward Citations)
GB362699A
Cited
US2538053A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1958-10-10 | 1959-04-11 | 1959-10-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1962-10-10 | 1963-04-11 | 1963-10-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1966-10-10 | 1967-04-11 | 1967-10-11 | $7700.00 | Window Closed / Lapsed |