Patent US3146593A successfully refreshed from Google Patents.
US3146593A
Expired / Lapsed
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Dual pump system and control valve assembly therefor
Assignee: Parker Hannifin Corp
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Filing: 1960-04-18
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Granted: 1964-09-01
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Expires: 1980-04-18
Abstract
No abstract record available.
Inventors
- 👤 Hugh J Stacey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:49
CPC Classifications
E; E02; E02F; E02F9/00; E02F9/20; E02F9/22; E02F3/00; E02F3/04; E02F3/28; E02F3/30; E02F3/32; E02F3/36; E02F3/42; E02F3/425; E02F9/08; E02F9/085; E02F9/2278; E02F9/2292; F; F15; F15B; F15B11/00; F15B11/16; F15B11/17; F15B13/00; F15B13/02; F15B13/06; F15B2211/00; F15B2211/20; F15B2211/205; F15B2211/20576; F15B2211/20584; F15B2211/30; F15B2211/305; F15B2211/30505; F15B2211/31; F15B2211/3105; F15B2211/3116; F15B2211/70; F15B2211/71; F15B2211/7142
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
138 words
A FLUID POWER SYSTEM COMPRISING AT LEAST TWO FLUID PRESSURE OPERATED UNITS WITH ASSOCIATED CONTROL VALVES AND PUMPS ARRANGED SO THAT SAID UNITS MAY BE OPERATED BY FLUID UNDER PRESSURE DELIVERED BY THE RESPECTIVE PUMPS, AND SO THAT ONE UNIT MAY BE OPERATED BY THE CONJOINT DISCHARGE OF BOTH PUMPS ONLY WHEN THE OTHER UNIT IS NOT IN OPERATION; AN UNLOADER FOR THE PUMP ASSOCIATED WITH SAID ONE UNIT OPERATIVE TO UNLOAD THAT PUMP WHEN THE FLUID PRESSURE DELIVERED TO SAID ONE UNIT EXCEEDS A PREDETERMINED VALUE; A FIRST CHECK VALVE DOWNSTREAM OF SAID UNLOADER FOR MAINTAINING SUCH FLUID PRESSURE TO SAID ONE UNIT WHILE SAID ONE PUMP IS UNLOADED; AND A SECOND CHECK VALVE BETWEEN SAID UNITS PERMITTING FLOW OF FLUID UNDER PRESSURE FROM THE OTHER PUMP TO SAID ONE UNIT FOR CONTINUED OPERATION OF THE LATTER.
Claim 2
Dependent Claim
138 words
A FLUID POWER SYSTEM COMPRISING AT LEAST TWO FLUID PRESSURE OPERATED UNITS WITH ASSOCIATED CONTROL VALVES AND PUMPS ARRANGED SO THAT SAID UNITS MAY BE OPERATED BY FLUID UNDER PRESSURE DELIVERED BY THE RESPECTIVE PUMPS, AND SO THAT ONE UNIT MAY BE OPERATED BY THE CONJOINT DISCHARGE OF BOTH PUMPS ONLY WHEN THE OTHER UNIT IS NOT IN OPERATION; AN UNLOADER FOR THE PUMP ASSOCIATED WITH SAID ONE UNIT OPERATIVE TO UNLOAD THAT PUMP WHEN THE FLUID PRESSURE DELIVERED TO SAID ONE UNIT EXCEEDS A PREDETERMINED VALUE; A FIRST CHECK VALVE DOWNSTREAM OF SAID UNLOADER FOR MAINTAINING SUCH FLUID PRESSURE TO SAID ONE UNIT WHILE SAID ONE PUMP IS UNLOADED; AND A SECOND CHECK VALVE BETWEEN SAID UNITS PERMITTING FLOW OF FLUID UNDER PRESSURE FROM THE OTHER PUMP TO SAID ONE UNIT FOR CONTINUED OPERATION OF THE LATTER.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1967-09-01 | 1968-03-02 | 1968-09-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1971-09-01 | 1972-03-02 | 1972-09-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1975-09-01 | 1976-03-02 | 1976-09-01 | $7700.00 | Window Closed / Lapsed |