Patent US3145964A successfully refreshed from Google Patents.
US3145964A
Expired / Lapsed
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Hydraulic mine prop
Assignee: Individual
•
Filing: 1963-05-09
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Granted: 1964-08-25
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Expires: 1983-05-09
Abstract
No abstract record available.
Inventors
- 👤 Groetschel Karl Maria
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:07
CPC Classifications
E; E21; E21D; E21D15/00; E21D15/14; E21D15/44
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
95 words
IN A HYDRAULIC MINE PROP USING A PRESSURE MEDIUM ACTING UPON A PISTON TO PROVIDE A PROP SETTING FORCE, THE IMPROVEMENT COMPRISING: MEANS FOR INCREASING THE SETTING FORCE OF A PROP AND INCLUDING A HYDRAULIC PRESSURE ASSEMBLY HAVING A SHORT STROKE IN COMPARISON TO THE STROKE OF A PROP, SAID ASSEMBLY ENCLOSING AN END OF SUCH PROP BUT BEING OPERABLE INDEPENDENTLY THEREOF, SAID ASSEMBLY HAVING A PISTON FORMED AS A RECEPTACLE FOR EMBRACING THE END OF SUCH PROP, SAID PISTON HAVING A PISTON AREA WHICH IS SUBSTANTIALLY LARGER THAN THE PISTON AREA OF SUCH PROP.
Claim 2
Dependent Claim
95 words
IN A HYDRAULIC MINE PROP USING A PRESSURE MEDIUM ACTING UPON A PISTON TO PROVIDE A PROP SETTING FORCE, THE IMPROVEMENT COMPRISING: MEANS FOR INCREASING THE SETTING FORCE OF A PROP AND INCLUDING A HYDRAULIC PRESSURE ASSEMBLY HAVING A SHORT STROKE IN COMPARISON TO THE STROKE OF A PROP, SAID ASSEMBLY ENCLOSING AN END OF SUCH PROP BUT BEING OPERABLE INDEPENDENTLY THEREOF, SAID ASSEMBLY HAVING A PISTON FORMED AS A RECEPTACLE FOR EMBRACING THE END OF SUCH PROP, SAID PISTON HAVING A PISTON AREA WHICH IS SUBSTANTIALLY LARGER THAN THE PISTON AREA OF SUCH PROP.
References Cited (Backward Citations)
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Cited
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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) | 1967-08-25 | 1968-02-24 | 1968-08-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1971-08-25 | 1972-02-24 | 1972-08-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1975-08-25 | 1976-02-24 | 1976-08-25 | $7700.00 | Window Closed / Lapsed |