Power transmission
Abstract
Abstract A VARIABLE DISPLACEMENT HYDRAULIC PUMP OR MOTOR UNIT IS BIASED TOWARD NEUTRAL BY CENTERING SPRINGS IN THE CASE OF THE PUMP AND TOWARD MAXIMUM DISPLACEMENT IN THE CASE OF THE MOTOR. HYDRAULIC SERVOMOTORS ARE CONTROLLED BY FOLLOW-UP SERVOVALVES TO OPPOSE THIS BIAS FOR ADJUSTING THE DISPLACEMENT NORMALLY. A LOAD RESPONSIVE VALVE IS CONNECTED IN PARALLEL WITH THE SERVOVALVE OR VALVES TO DUMP THE PRESSURE APPLIED TO THE SERVOMOTOR AND ALLOW THE BIASING SPRINGS TO REDUCE THE DISPLACEMENT IN THE CASE OF THE PUMP OR TO INCREASE IT IN THE CASE OF THE MOTOR. A HYDRAULIC VARIABLE SPEED TRANSMISSION UTILIZING SUCH A PUMP AND SUCH A MOTOR WITH A SINGLE LOAD LIMITING VALVE IS ARRANGED TO GIVE PRIORITY TO LOAD LIMITING ACTION AT THE MOTOR BEFORE SUCH ACTION OCCURS AT THE PUMP.
Inventors
- 👤 Donald C Connett
Bibliographic Details
Claims Analysis
Total Claims: 0References Cited (Backward Citations)
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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) | 1974-09-20 | 1975-03-22 | 1975-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-20 | 1979-03-22 | 1979-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-20 | 1983-03-22 | 1983-09-21 | $7700.00 | Window Closed / Lapsed |