Patent US1874418A successfully refreshed from Google Patents.
Patent US2806959A successfully refreshed from Google Patents.
US2806959A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of detecting surface discontinuities
Assignee: Switzer Brothers Inc
•
Filing: 1954-07-26
•
Granted: 1957-09-17
•
Expires: 1974-07-26
Abstract
No abstract record available.
Inventors
- 👤 Forest Taber De
- 👤 Donald W Parker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 16:53
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/84; G01N21/88; G01N21/91; Y; Y10; Y10S; Y10S252/00; Y10S252/96
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
43 words
THE METHOD OF DETECTING SURFACE DISCONTINUITIES IN TEST PIECES, WHICH COMPRISES APPLYING TO THE SURFACE OF A TEST PIECE A COATING OF A LIQUID PENETRANT THAT IS NONWATER MISCIBLE AND CAPABLE OF PENETRATING SURFACE DISCONTINUITIES THAT MAY BE PRESENT, APPLYING OVER THE R
Claim 2
Independent Claim
43 words
THE METHOD OF DETECTING SURFACE DISCONTINUITIES IN TEST PIECES, WHICH COMPRISES APPLYING TO THE SURFACE OF A TEST PIECE A COATING OF A LIQUID PENETRANT THAT IS NONWATER MISCIBLE AND CAPABLE OF PENETRATING SURFACE DISCONTINUITIES THAT MAY BE PRESENT, APPLYING OVER THE R
References Cited (Backward Citations)
US2259400A
Cited
US2478951A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-09-16 | 1961-03-18 | 1961-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-09-16 | 1965-03-18 | 1965-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-09-16 | 1969-03-18 | 1969-09-17 | $7700.00 | Window Closed / Lapsed |