US2853406A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Metal coating
Assignee: ZF Active Safety US Inc
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Filing: 1956-04-17
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Granted: 1958-09-23
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Expires: 1976-04-17
Abstract
No abstract record available.
Inventors
- 👤 Ludwig K Schuster
- 👤 Jr Alfonso L Baldi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:48
CPC Classifications
C; C23; C23C; C23C22/00; C23C22/05; C23C22/06; C23C22/24
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
76 words
A METHOD FOR IMPROVING THE SURFACE OF CORRODIBLE FERROUS METAL WHICH COMPRISES ETCHING THE SURFACE OF SAID METAL WITH NITRIC ACID HAVING A CONCENTRATION OF FROM 1 TO 20% BY WEIGHT FOR A PERIOD OF 2 TO 70 SECONDS AT A TEMPERATURE OF 60 TO 150*F., APPLYING ON THE ETCHED SURFACE AN AQUEOUS CHROMIC ACID SOLUTION HAVING A CONCENTRATION OF FROM 1/2 TO 10% BY WEIGHT, AND DRY, ING THE CHROMIC ACID SOLUTION ON SAID SURFACE,
Claim 2
Independent Claim
76 words
A METHOD FOR IMPROVING THE SURFACE OF CORRODIBLE FERROUS METAL WHICH COMPRISES ETCHING THE SURFACE OF SAID METAL WITH NITRIC ACID HAVING A CONCENTRATION OF FROM 1 TO 20% BY WEIGHT FOR A PERIOD OF 2 TO 70 SECONDS AT A TEMPERATURE OF 60 TO 150*F., APPLYING ON THE ETCHED SURFACE AN AQUEOUS CHROMIC ACID SOLUTION HAVING A CONCENTRATION OF FROM 1/2 TO 10% BY WEIGHT, AND DRY, ING THE CHROMIC ACID SOLUTION ON SAID SURFACE,
Claim 3
Dependent Claim
58 words
IN A PROCESS FOR PROLONGING THE EFFECTIVENESS OF AN AQUEOUS NITRIC ACID ETCHING BATH IN THE ETCHING OF FERROUS METAL THE STEP OF BUBBLING A NON-REACTIVE GAS THROUGH THE BATH DURING THE ETCHING, THE BUBBLING BEING IN QUANTITITES OF AT LEAST 15 CUBIC FEET PER MINUTE FOR EACH SQUARE FOOT OF MEAN HORIZONTAL CROSS-SECTIONAL AREA OF THE BATH.
Claim 4
Dependent Claim
58 words
IN A PROCESS FOR PROLONGING THE EFFECTIVENESS OF AN AQUEOUS NITRIC ACID ETCHING BATH IN THE ETCHING OF FERROUS METAL THE STEP OF BUBBLING A NON-REACTIVE GAS THROUGH THE BATH DURING THE ETCHING, THE BUBBLING BEING IN QUANTITITES OF AT LEAST 15 CUBIC FEET PER MINUTE FOR EACH SQUARE FOOT OF MEAN HORIZONTAL CROSS-SECTIONAL AREA OF THE BATH.
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) | 1961-09-22 | 1962-03-24 | 1962-09-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-09-22 | 1966-03-24 | 1966-09-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-09-22 | 1970-03-24 | 1970-09-23 | $7700.00 | Window Closed / Lapsed |