US2839918A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flaw detection
Assignee: Individual
•
Filing: 1949-04-06
•
Granted: 1958-06-24
•
Expires: 1969-04-06
Abstract
No abstract record available.
Inventors
- 👤 Robert C Switzer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:08
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/84; G01N21/88; G01N21/91
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
131 words
IN A METHOD OF DETECTING THE PRESENCE OF FLAWS IN THE SURFACE LAYER OF A METALLIC ARTICLE, THE STEPS COMPRISING APPLYING TO THE SURFACE OF SAID ARTICLE A SOLUTION CONTAINING AN OIL AND A COLORING AMTERIAL, MAINTAINING THE SOLUTION IN CONTACT WITH THE SURFACE FOR A PERIOD OF TIME OF SUFFICIENT DURATION THAT THE SOLUTION MAY PENETRATE SAID FLAWS, REMOVING FROM THE SURFACE THE SOLUTION WHICH HAS NOT PENETRATED SAID FLAWS, AND APPLYING TO THE SURFACE A FINELY DIVIDED ABSORBENT MATERIAL, THE PRESENCE OF FLAWS IN THE SURFACE LAYERS OF SAID METALLIC ARTICLE BEING VISIBLY INDICATED BY A COLORING OF THE ABSORBENT MATERIAL CONTAINED ADJACENT SAID FLAWS BY THE COLORING MATERIAL CONTAINED IN THE SOLUTION UPON THE SEEPING OF THE LATTER OF OF SAID FLAWS ONTO THE SURFACE OF THE ARTICLE.
Claim 2
Dependent Claim
131 words
IN A METHOD OF DETECTING THE PRESENCE OF FLAWS IN THE SURFACE LAYER OF A METALLIC ARTICLE, THE STEPS COMPRISING APPLYING TO THE SURFACE OF SAID ARTICLE A SOLUTION CONTAINING AN OIL AND A COLORING AMTERIAL, MAINTAINING THE SOLUTION IN CONTACT WITH THE SURFACE FOR A PERIOD OF TIME OF SUFFICIENT DURATION THAT THE SOLUTION MAY PENETRATE SAID FLAWS, REMOVING FROM THE SURFACE THE SOLUTION WHICH HAS NOT PENETRATED SAID FLAWS, AND APPLYING TO THE SURFACE A FINELY DIVIDED ABSORBENT MATERIAL, THE PRESENCE OF FLAWS IN THE SURFACE LAYERS OF SAID METALLIC ARTICLE BEING VISIBLY INDICATED BY A COLORING OF THE ABSORBENT MATERIAL CONTAINED ADJACENT SAID FLAWS BY THE COLORING MATERIAL CONTAINED IN THE SOLUTION UPON THE SEEPING OF THE LATTER OF OF SAID FLAWS ONTO THE SURFACE OF THE ARTICLE.
References Cited (Backward Citations)
GB436873A
Cited
FR822308A
Cited
US2259400A
Cited
FR50147E
Cited
CH224242A
Cited
US2405078A
Cited
US2478951A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-06-23 | 1961-12-23 | 1962-06-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-06-23 | 1965-12-23 | 1966-06-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-06-23 | 1969-12-23 | 1970-06-24 | $7700.00 | Window Closed / Lapsed |