US2789930A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of nitriding ferrous alloys
Assignee: Individual
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Filing: 1954-10-11
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Granted: 1957-04-23
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Expires: 1974-10-11
Abstract
No abstract record available.
Inventors
- 👤 William F Engelhard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 17:46
CPC Classifications
C; C23; C23C; C23C8/00; C23C8/06; C23C8/08; C23C8/24; C23C8/26
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
148 words
THE METHOD OF PREPARING, FOR NITRIDING, AN ARTICLE OF A FERROUS ALLOY INCLUDING CHROME AND HAVING A FILM OF CHROME OXIDE SERVING AS A NITRIDING BARRIER, COMPRISING POSITIONING SAID ARTICLE IN A CHAMBER, CIRCULATING AMMONIA GAS AROUND SAID ARTICLE IN SAID CHAMBER, MOISTENING A MASS WITH HYDROCHLORIC ACID, POSITIONING SAID MASS IN SAID CHAMBER IN SPACED APART RELATION TO SAID ARTICLE, HEATING SAID CHAMBER TO PROGRESSIVELY HEAT THE ARTICLE UP TO ITS NITRIDING TEMPERATURE, WHEREBY HYDROCHOLORIC ACID FUMES OF SAID MASS WILL COMBINE WITH THE AMMOMIA GAS TO FORM AMMONIUM CHLORIDE VAPORS WHICH WILL CONDENSE ON THE SURFACES OF SAID ARTICLE AND ATTACK THE CHROME OXIDE COATING THEREOF, AND PROGRESSIVELY HEATING AND CHAMBER TO PROGRESSIVELY BRING THE ARTICLE UP TO ITS NITRIDING TEMPERATURE, WHEREBY THE PREVIOUSLY CONDENSED AMMONIUM CHLORIDE VAPORS VOLATILIZE FROM SAID ARTICLE SO THAT NITRIDING MAY BE PROCESSED WITH ON CIRCULATING AMMONIA GAS ONTO SAID ARTICLE.
Claim 2
Independent Claim
148 words
THE METHOD OF PREPARING, FOR NITRIDING, AN ARTICLE OF A FERROUS ALLOY INCLUDING CHROME AND HAVING A FILM OF CHROME OXIDE SERVING AS A NITRIDING BARRIER, COMPRISING POSITIONING SAID ARTICLE IN A CHAMBER, CIRCULATING AMMONIA GAS AROUND SAID ARTICLE IN SAID CHAMBER, MOISTENING A MASS WITH HYDROCHLORIC ACID, POSITIONING SAID MASS IN SAID CHAMBER IN SPACED APART RELATION TO SAID ARTICLE, HEATING SAID CHAMBER TO PROGRESSIVELY HEAT THE ARTICLE UP TO ITS NITRIDING TEMPERATURE, WHEREBY HYDROCHOLORIC ACID FUMES OF SAID MASS WILL COMBINE WITH THE AMMOMIA GAS TO FORM AMMONIUM CHLORIDE VAPORS WHICH WILL CONDENSE ON THE SURFACES OF SAID ARTICLE AND ATTACK THE CHROME OXIDE COATING THEREOF, AND PROGRESSIVELY HEATING AND CHAMBER TO PROGRESSIVELY BRING THE ARTICLE UP TO ITS NITRIDING TEMPERATURE, WHEREBY THE PREVIOUSLY CONDENSED AMMONIUM CHLORIDE VAPORS VOLATILIZE FROM SAID ARTICLE SO THAT NITRIDING MAY BE PROCESSED WITH ON CIRCULATING AMMONIA GAS ONTO SAID ARTICLE.
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) | 1960-04-22 | 1960-10-22 | 1961-04-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-04-22 | 1964-10-22 | 1965-04-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-04-22 | 1968-10-22 | 1969-04-23 | $7700.00 | Window Closed / Lapsed |