US3171439A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pilot operated valve
Assignee: Parker Hannifin Corp
•
Filing: 1962-03-07
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Granted: 1965-03-02
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Expires: 1982-03-07
Abstract
No abstract record available.
Inventors
- 👤 Zdenek J Lansky
- 👤 Kurt W Leibfritz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 14:04
CPC Classifications
F; F16; F16K; F16K31/00; F16K31/12; F16K31/36; F16K31/40; F15; F15B; F15B13/00; F15B13/02; F15B13/04; F15B13/042; F15B13/043; F15B13/0431; Y; Y10; Y10T; Y10T137/00; Y10T137/8593; Y10T137/86493; Y10T137/86574; Y10T137/86582; Y10T137/86614; Y10T137/86622; Y10T137/8663
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
172 words
A VALVE COMPRISING A MAIN HOUSING HAVING A PLURALITY OF PORTS, A VALVE MEMBER FOR CONTROLLING FLOW OF FLUID THROUGH SAID PORTS, SAID HOUSING HAVING A LARGE AND A SMALL DIAMETER BORE, A PILOT VALVE HOUSING HAVING A CYLINDRICAL PORTION EXTENDING INTO SAID LARGE BORE, A PISTON HAVING A SMALL DIAMETER AND EXTENDING INTO SAID SMALL BORE AND A LARGE DIAMETER PORTION EXTENDING INTO SAID LARGE BORE, ONE OF SAID PORTIONS HAVING A RECESS AND THE OTHER OF SAID PORTIONS EXTENDING INTO SAID RECESS AND SEALED WITH RESPECT TO THE WALL THEREOF BY SEALING MEANS TO PROVIDE A LARGE EFFECTIVE AREA ON SAID PISTON, SAID PISTON HAVING A SMALL EFFECTIVE AREA FACING OPPOSITE TO THE LARGE EFFECTIVE AREA, A PASSAGE BETWEEN THE MAIN HOUSING AND SAID RECESSED PORTION, MEANS INCLUDING SAID PASSAGE FOR DIRECTING FLUID UNDER PRESSURE FROM ONE OF SAID PORTS TO SAID LARGE EFFECTIVE AREA FOR MOVING THE PISTON IN ONE DIRECTION, AND MEANS FOR EXHAUSTING THE FLUID FROM THE LARGE EFFECTIVE AREA, WHEREBY FLUID ACTING AGAINST SAID SMALL EF-
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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) | 1968-03-01 | 1968-08-31 | 1969-03-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-03-01 | 1972-08-31 | 1973-03-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-03-01 | 1976-08-31 | 1977-03-02 | $7700.00 | Window Closed / Lapsed |