Patent US3587399A successfully refreshed from Google Patents.
US3587399A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control valve means for a two-way hydraulic cylinder
Assignee: Deere and Co
•
Filing: 1969-05-02
•
Granted: 1971-06-28
•
Expires: 1989-05-02
Abstract
Abstract A CONTROL VALVE FOR A TWO-WAY HYDRAULIC CYLINDER INCLUDES A PRESSURE-COMPENSATED FLOW CONTROL VALVE FOR MAINTAINING A CONSTANT PREDETERMINED FLOW RATE TO THE HYDRAULIC CYLINDER AND HAS A PAIR OF CHECK VALVES FOR PREVENTING THE RETURN OF FLUID FROM THE ENDS OF THE HYDRAULIC CYLINDER, A PAIR OF OPPOSED HYDRAULICALLY OPERATED PISTONS RESPONSIVE TO FLUID PRESSURE BETWEEN THEIR FACES FOR RESPECTIVELY ENGAGING AND UNSEATING THE CHECK VALVES AND A MANUALLY OPERATED SPOOL-TYPE DIRECTION CONTROL VALVE FOR SELECTIVELY CONNECTING THE OUTLETS OF THE PRESSURE-COMPENSATED VALVE TO ONE OR THE OTHER OF THE ENDS OF THE HYDRAULIC CYLINDER AND TO THE FACES OF THE OPPOSED PISTONS.
Inventors
- 👤 Donald James Parquet
- 👤 Daniel Luce Hall
- 👤 Stanley Martin Gregerson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:42
CPC Classifications
F; F15; F15B; F15B13/00; F15B13/02; F15B13/04; F15B13/0416; F15B13/0417; F15B13/01
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-06-27 | 1974-12-27 | 1975-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-27 | 1978-12-27 | 1979-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-27 | 1982-12-27 | 1983-06-28 | $7700.00 | Window Closed / Lapsed |