US3425229A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Mine roof support
Assignee: Individual
•
Filing: 1963-11-12
•
Granted: 1969-02-04
•
Expires: 1983-11-12
Abstract
No abstract record available.
Inventors
- 👤 Karl Maria Groetschel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 03:15
CPC Classifications
E; E21; E21D; E21D23/00; E21D23/0047; E21D23/0052; E21D23/006; E21D23/0069
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
DE975201C
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GB772868A
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GB865922A
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GB882933A
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GB866108A
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DE1112480B
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DE1119803B
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US3008298A
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US3174289A
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US3197966A
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GB905312A
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FR1278986A
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US3240021A
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FR1312708A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-02-04 | 1972-08-05 | 1973-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-02-04 | 1976-08-05 | 1977-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-02-04 | 1980-08-05 | 1981-02-04 | $7700.00 | Window Closed / Lapsed |