Hydraulic actuator with center lock
Abstract
Abstract MAIN PISTON FOR MOVING IT TO ITS DEAD CENTER LOCKED POSITION IN THE DIRECTION OPPOSITE TO THE DIRECTION OF MOVEMENT BY THE AUXILIARY PISTON. SPRING BIASED DETENT MEANS HOLD THE LOCKING ELEMENTS IN UNLOCKED POSITION AGAINST INVOLUNTARY, RANDOM MOVEMENTS. A HYDRAULIC ACTUATOR HAVING A MAIN PISTON MOVABLE TO EXTENDED AND RETRACTED EXTREME POSITIONS OF OPERATION AND PROVIDED WITH A CENTER LOCK IN A POSITION INTERMEDIATE THE EXTREME POSITIONS. THE LOCK IS LOCATED INTERNALLY OF THE PISTON FOR COMPACTNESS AND A LOCKING-UNLOCKING PISTON IS PROVIDED TO OPERATE THE LOCKING ELEMENTS. AN AUXILIARY PISTON IS PROVIDED FOR MOVING THE MAIN PISTON TO ITS CENTER LOCKED POSITION BY ABUTTING A PART MOVABLE WITH THE MAIN PISTON, FOR MOVEMENT IN ONE DIRECTION ONLY. ACTUATORS MAY BE MOUNTED IN FACE-TO-FACE PAIRS TO SECURE MOVEMENT IN OPPOSITE DIRECTIONS TO THE DEAD CENTER POSITION, OR A SINGLE ACTUATOR MAY INCLUDE A WORKING SURFACE ON THE
Inventors
- 👤 Donald L Nepp
Bibliographic Details
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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) | 1974-09-19 | 1975-03-21 | 1975-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-19 | 1979-03-21 | 1979-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-19 | 1983-03-21 | 1983-09-20 | $7700.00 | Window Closed / Lapsed |