Patent US3421364A successfully refreshed from Google Patents.
US3421364A
Expired / Lapsed
US
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Methods of and apparatus for measuring the hardness of materials
Assignee: GKN Group Services Ltd
•
Filing: 1965-08-04
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Granted: 1969-01-14
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Expires: 1985-08-04
Abstract
No abstract record available.
Inventors
- 👤 Harold Kenneth Moneypenny
- 👤 Ronald Kitchener
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:51
CPC Classifications
G; G01; G01N; G01N3/00; G01N3/40; G01N3/48; G01N2203/00; G01N2203/02; G01N2203/06; G01N2203/0617; G01N2203/0623
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1393989A
Cited
US1581839A
Cited
US2323925A
Cited
US2834203A
Cited
US2834202A
Cited
US3298222A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-01-14 | 1972-07-15 | 1973-01-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-01-14 | 1976-07-15 | 1977-01-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-01-14 | 1980-07-15 | 1981-01-14 | $7700.00 | Window Closed / Lapsed |