US3752039A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Master-slave hydraulic control system
Assignee: International Business Machines Corp
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Filing: 1971-12-22
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Granted: 1973-08-14
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Expires: 1991-12-22
Abstract
Abstract A master-slave hydraulic control system is disclosed which provides an improved synchronization control together with the ability to rapidly change the stroking characteristics of the cylinders by removing and inserting a second control member into a mounting apparatus moved with the master control piston. Further, the two pistons are continuously maintained in close synchronization and are not allowed to get out of synchronization by the accumulation of more than a slight quantity of captive hydraulic fluid or oil.
Inventors
- 👤 T Hewins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:09
CPC Classifications
F; F15; F15B; F15B7/00; F15B7/06; F15B7/10; Y; Y10; Y10T; Y10T83/00; Y10T83/869; Y10T83/8821; Y10T83/8837
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
115 words
A master-slave hydraulic, reversible system comprising: a slave cylinder having a piston; a master cylinder having a piston; a pressure line connecting said cylinders to form a captive volume of a pressure medium; and a pressure source for furnishing working pressure alternately to said cylinders; the improvement comprising: a first position sensing means for sensing the position of said slave cylinder piston and providing an output; a second position sensing means for sensing the position of said master cylinder piston and providing an output; and a captive volume pressure medium relief means responsively controlled by the outputs of said sensing means to automatically synchronize the movemets of said pistons during the operation of said system.
Claim 2
Dependent Claim
115 words
A master-slave hydraulic, reversible system comprising: a slave cylinder having a piston; a master cylinder having a piston; a pressure line connecting said cylinders to form a captive volume of a pressure medium; and a pressure source for furnishing working pressure alternately to said cylinders; the improvement comprising: a first position sensing means for sensing the position of said slave cylinder piston and providing an output; a second position sensing means for sensing the position of said master cylinder piston and providing an output; and a captive volume pressure medium relief means responsively controlled by the outputs of said sensing means to automatically synchronize the movemets of said pistons during the operation of said system.
Claim 3
Dependent Claim
30 words
The system of claim 1 wherein said first sensing means completes an electrical connection to operate said relief means, whereby excessive captive oil is removed from said captive oil volume.
Claim 4
Dependent Claim
64 words
The system of claim 2 wherein said second sensing means breaks an electrical connection to prevent further operation of said relief means to prevent additional captive oil from being removed thereby limiting the time thAt captive oil may be removed from said captive oil volume to the time between the functioning of said first sensing means and the functioning of said second sensing means.
Claim 5
Dependent Claim
23 words
The system of claim 1 wherein said first and second sensing means are positioned to detect the midpoint of travel of said pistons.
Claim 6
Dependent Claim
69 words
The system of claim 1 wherein said improvement further comprises: stroke length control means; said stroke length control means further comprising a sensing means; and limit defining means movably positioned to intermittently activate and deactivate said sensing means in response to the movement of the piston of one of said cylinders, said sensing means operatively connected to a means for reversing the stroke of said pistons within said cylinders.
Claim 7
Dependent Claim
27 words
The system of claim 5 wherein said limit defining means further comprises a preselected electrical component for altering the operating characteristics of related and associated electrical circuits.
Claim 8
Dependent Claim
18 words
The system of claim 5 wherein said limit defining means is adapted to be removable for easy substitution.
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) | 1976-08-13 | 1977-02-12 | 1977-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-13 | 1981-02-12 | 1981-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-13 | 1985-02-12 | 1985-08-14 | $7700.00 | Window Closed / Lapsed |