US3241801A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulic prop
Assignee: Rheinstahl Wanheim GmbH
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Filing: 1964-11-30
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Granted: 1966-03-22
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Expires: 1984-11-30
Abstract
No abstract record available.
Inventors
- 👤 Wilkenloh Wilhelm
- 👤 Jager Erich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:43
CPC Classifications
E; E21; E21D; E21D23/00; E21D23/006; E21D23/0069; E21D15/00; E21D15/14; E21D15/44; F; F15; F15B; F15B15/00; F15B15/08; F15B15/14; F15B15/16
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
149 words
AN EXTENSIBLE MULTI-STAGE HYDRAULIC PROP, COMPRISING A FIRST TUBE; AT LEAST ONE FIRST STAGE INCLUDING A SECOND TUBE HAVING A PORTION RECIPROCABLY TELESCOPED INTO SAID FIRST TUBE; AND A SECOND STAGE INCLUDING A THIRD TUBE HAVING A PORTION RECIPROCABLY TELESCOPED INTO SAID SECOND TUBE, SAID PROP DEFINING A SINGLE PRESSURE CHAMBER AND SAID SECOND STAGE COMPRISING A PISTON LOCATED AT ONE END OF SAID CHAMBER, EACH OF SAID STAGES HAVING AN EFFECTIVE SURFACE WHICH IS ACTED UPON BY FLUID WHEN THE PROP IS BEING EXTENDED IN RESPONSE TO ADMISSION OF HYDRAULIC FLUID INTO SAID CHAMBER, THE CROSS-SECTIONAL AREA OF EACH EFFECTIVE SURFACE BEING SUBSTANTIALLY THE SAME SO THAT THE PROP OFFERS A SUBSTANTIALLY CONSTANT RESISTANCE TO STRESSES WHICH END TO CONTRACT THE SAME AND THE CROSS-SECTIONAL AREA OF THE EFFECTIVE SURFACE IN SAID SECOND STAGE AT LEAST APPROXIMATING THE CROSS-SECTIONAL AREA OF THE INTERNAL SPACE OF SAID FIRST TUBE.
Claim 2
Dependent Claim
149 words
AN EXTENSIBLE MULTI-STAGE HYDRAULIC PROP, COMPRISING A FIRST TUBE; AT LEAST ONE FIRST STAGE INCLUDING A SECOND TUBE HAVING A PORTION RECIPROCABLY TELESCOPED INTO SAID FIRST TUBE; AND A SECOND STAGE INCLUDING A THIRD TUBE HAVING A PORTION RECIPROCABLY TELESCOPED INTO SAID SECOND TUBE, SAID PROP DEFINING A SINGLE PRESSURE CHAMBER AND SAID SECOND STAGE COMPRISING A PISTON LOCATED AT ONE END OF SAID CHAMBER, EACH OF SAID STAGES HAVING AN EFFECTIVE SURFACE WHICH IS ACTED UPON BY FLUID WHEN THE PROP IS BEING EXTENDED IN RESPONSE TO ADMISSION OF HYDRAULIC FLUID INTO SAID CHAMBER, THE CROSS-SECTIONAL AREA OF EACH EFFECTIVE SURFACE BEING SUBSTANTIALLY THE SAME SO THAT THE PROP OFFERS A SUBSTANTIALLY CONSTANT RESISTANCE TO STRESSES WHICH END TO CONTRACT THE SAME AND THE CROSS-SECTIONAL AREA OF THE EFFECTIVE SURFACE IN SAID SECOND STAGE AT LEAST APPROXIMATING THE CROSS-SECTIONAL AREA OF THE INTERNAL SPACE OF SAID FIRST TUBE.
References Cited (Backward Citations)
US2364741A
Cited
FR1343862A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1969-03-21 | 1969-09-20 | 1970-03-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-03-21 | 1973-09-20 | 1974-03-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-03-21 | 1977-09-20 | 1978-03-22 | $7700.00 | Window Closed / Lapsed |