Patent US3587750A successfully refreshed from Google Patents.
US3587750A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Row marker
Assignee: Deere and Co
•
Filing: 1969-01-27
•
Granted: 1971-06-28
•
Expires: 1989-01-27
Abstract
Abstract ROW MARKERS FOR AGRICULTURAL IMPLEMENTS IN WHICH THE MARKER ARMS ARE PIVOTALLY MOUNTED TO THE IMPLEMENT, ARE GRAVITY URGED DOWNWARDLY TO THE WORKING POSITIONS, AND ARE RAISED BY HYDRAULIC CYLINDERS. THE CYLINDERS ARE CONNECTED IN PARALLEL AND ARE ALTERNATELY CONNECTABLE WITH A FLUID SOURCE AND RESERVOIR PROVIDED ON A PROPELLING VEHICLE. A SOLENOID VALVE IS ASSOCIATED WITH EACH CYLINDER AND NORMALLY PREVENTS THE FLOW OF FLUID FROM THE CYLINDERS, BUT PROVIDE FREE FLOW OF FLUID TO AND FROM THE CYLINDERS WHEN ACTIVATED SO THAT THE MARKER ARMS ARE SELECTIVELY LOWERED BY SELECTIVELY ACTIVATING THE SOLENOID VALVES.
Inventors
- 👤 John Isaac Cantral
- 👤 Robert Otto Taube
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 22:57
CPC Classifications
A; A01; A01B; A01B69/00; A01B69/02; A01B69/024
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 |