US3301519A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Double telescoping hydraulic prop
Assignee: Gewerkschaft Eisenhutte Westfalia GmbH
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Filing: 1965-10-18
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Granted: 1967-01-31
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Expires: 1985-10-18
Abstract
No abstract record available.
Inventors
- 👤 Dommann Gunther
- 👤 Hoffmann Erich
- 👤 Floter Manfred
- 👤 Warns Egon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 16:45
CPC Classifications
E; E21; E21D; E21D15/00; E21D15/14; E21D15/44; F; F16; F16J; F16J13/00; F16J13/02
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
111 words
A MULTIPLE TELESCOPING HYDRAULIC PROP HAVING A SINGLE HYDRAULIC FLUID SYSTEM TO ALL TELESCOPING PISTONS THEREOF WHEREIN SAID PROP CONTAINS MEANS TO RESTRAIN SAID LARGEST PISTON FROM FULLY EXTENDING TO ITS MAXIMUM PRIOR TO A SMALLER PISTON CONTACTING A SURFACE TO BE SUPPORTED BY SAID PROP; AND CHECK VALVE MEANS BETWEEN TWO SUCCESTIVE PISTONS OPERATIVE TO PERMIT FLOW OF HYDRAULIC FLUID THERETHROUGH FROM SAID HYDRAULIC SYSTEM INTO SUPPORTING RELATION WITH THE SMALLER OF SAID SUCCESSIVE PISTONS AND OPERATIVE TO PERMIT FLOW OF SAID HYDRAULIC FLUID FROM SUPPORTING RELATION WITH RESPECT TO SAID SMALLER PISTON TO A SOURCE OF SAID HYDRAULIC FLUID ONLY WHEN SAID LARGER PISTON IS UNSUPPORTED BY HYDRAULIC FLUID.
Claim 2
Dependent Claim
111 words
A MULTIPLE TELESCOPING HYDRAULIC PROP HAVING A SINGLE HYDRAULIC FLUID SYSTEM TO ALL TELESCOPING PISTONS THEREOF WHEREIN SAID PROP CONTAINS MEANS TO RESTRAIN SAID LARGEST PISTON FROM FULLY EXTENDING TO ITS MAXIMUM PRIOR TO A SMALLER PISTON CONTACTING A SURFACE TO BE SUPPORTED BY SAID PROP; AND CHECK VALVE MEANS BETWEEN TWO SUCCESTIVE PISTONS OPERATIVE TO PERMIT FLOW OF HYDRAULIC FLUID THERETHROUGH FROM SAID HYDRAULIC SYSTEM INTO SUPPORTING RELATION WITH THE SMALLER OF SAID SUCCESSIVE PISTONS AND OPERATIVE TO PERMIT FLOW OF SAID HYDRAULIC FLUID FROM SUPPORTING RELATION WITH RESPECT TO SAID SMALLER PISTON TO A SOURCE OF SAID HYDRAULIC FLUID ONLY WHEN SAID LARGER PISTON IS UNSUPPORTED BY HYDRAULIC FLUID.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-01-30 | 1970-08-01 | 1971-01-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-01-30 | 1974-08-01 | 1975-01-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-01-30 | 1978-08-01 | 1979-01-31 | $7700.00 | Window Closed / Lapsed |