Patent US2721835A successfully refreshed from Google Patents.
US2721835A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Surface treatment of aluminum articles
Assignee: Shwayder Brothers Inc
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Filing: 1951-07-07
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Granted: 1955-10-25
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Expires: 1971-07-07
Abstract
No abstract record available.
Inventors
- 👤 Willard G Axtell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 10:19
CPC Classifications
C; C25; C25D; C25D11/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
105 words
A METHOD OF SURFACE TREATING AN ALUMINUM ARTICLE, WHICH COMPRISES IMMERSING SAID ARTICLE IN AN ELECTROLYTIC SOLUTION CONSISTING OF ABOUT 0.3% CHROMIC ACID, AS CRO3, 1.68% PHOSPHORIC ACID, AND THE BALANCE WATER; MAINTAINING SAID SOLUTION AT A TEMPERATURE BETWEEN 60* F. AND 120* F.; PASSING AN ELECTRIC CURRENT THROUGH SAID ARTICLE AS THE ANODE AT FROM 2 TO 30 VOLTS, FOR A PERIOD OF BETWEEN 5 SECOND AND 2 MINUTES; REMOVING SAID ARTICLE FROM SAID ELECTROLYTE; AND, WITHOUT WASHING OR COMPLETE DRYING, DIPPING SAID ARTICLE IN A LIQUID SELECTED FROM THE GROUP CONSISTING OF ALKYD BASE ENAMELS, OIL VARNISH BASE ENAMELS, AND OIL BASE PAINTS.
Claim 2
Independent Claim
105 words
A METHOD OF SURFACE TREATING AN ALUMINUM ARTICLE, WHICH COMPRISES IMMERSING SAID ARTICLE IN AN ELECTROLYTIC SOLUTION CONSISTING OF ABOUT 0.3% CHROMIC ACID, AS CRO3, 1.68% PHOSPHORIC ACID, AND THE BALANCE WATER; MAINTAINING SAID SOLUTION AT A TEMPERATURE BETWEEN 60* F. AND 120* F.; PASSING AN ELECTRIC CURRENT THROUGH SAID ARTICLE AS THE ANODE AT FROM 2 TO 30 VOLTS, FOR A PERIOD OF BETWEEN 5 SECOND AND 2 MINUTES; REMOVING SAID ARTICLE FROM SAID ELECTROLYTE; AND, WITHOUT WASHING OR COMPLETE DRYING, DIPPING SAID ARTICLE IN A LIQUID SELECTED FROM THE GROUP CONSISTING OF ALKYD BASE ENAMELS, OIL VARNISH BASE ENAMELS, AND OIL BASE PAINTS.
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) | 1958-10-24 | 1959-04-25 | 1959-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1962-10-24 | 1963-04-25 | 1963-10-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1966-10-24 | 1967-04-25 | 1967-10-25 | $7700.00 | Window Closed / Lapsed |