US3142962A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control valve
Assignee: Caterpillar Inc
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Filing: 1963-02-25
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Granted: 1964-08-04
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Expires: 1983-02-25
Abstract
No abstract record available.
Inventors
- 👤 Kenneth R Lohbauer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 22:47
CPC Classifications
F; F15; F15B; F15B1/00; F15B1/02; F15B1/027; B; B60; B60T; B60T13/00; B60T13/10; B60T13/12; B60T13/14; B60T13/148
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
152 words
A CONTROL VALVE FOR USE IN COMBINATION WITH A HYDRAULIC SYSTEM INCLUDING A SOURCE OF WORKING FLUID, A PUMP DISPOSED TO DELIVER FLUID FROM THE SOURCE, AN OPEN CENTER SYSTEM AND A CLOSED CENTER SYSTEM WITH AN ACCUMULATOR, COMPRISING IN COMBINATION; FIRST VALVE MEANS IN COMMUNICATION WITH THE PUMP, THE OPEN CENTER SYSTEM AND THE CLOSED CENTER SYSTEM; SAID VALVE MEANS HAVING A RESTRICTIVE ORIFICE HYDRAULICALLY DISPOSED BETWEEN THE PUMP AND CLOSED CENTER SYSTEM WHEREBY A PRESSURE DROP IS DEVELOPED WHEN THE VOLUMETRIC OUTPUT OF THE PUMP IS GREATER THAN THE FLUID FLOW THROUGH THE ORIFICE; AND MEANS RESPONSIVE TO THE PRESSURE DROP ACROSS THE ORFICE TO COMMUNICATE THE PUMP WITH THE OPEN CENTER SYSTEM THROUGH SAID VALVE MEANS WHEREIN THE PHYSICAL AREA OF COMMUNICATION IS A DIRECT FUNCTION OF THE MAGNITUDE OF THE PRESSURE DROP ACROSS THE ORIFICE WHEREBY THE VOLUME OF FLUID FLOW THROUGH THE ORIFICE IS MAINTAINED RELATIVELY CONSTANT.
Claim 2
Dependent Claim
152 words
A CONTROL VALVE FOR USE IN COMBINATION WITH A HYDRAULIC SYSTEM INCLUDING A SOURCE OF WORKING FLUID, A PUMP DISPOSED TO DELIVER FLUID FROM THE SOURCE, AN OPEN CENTER SYSTEM AND A CLOSED CENTER SYSTEM WITH AN ACCUMULATOR, COMPRISING IN COMBINATION; FIRST VALVE MEANS IN COMMUNICATION WITH THE PUMP, THE OPEN CENTER SYSTEM AND THE CLOSED CENTER SYSTEM; SAID VALVE MEANS HAVING A RESTRICTIVE ORIFICE HYDRAULICALLY DISPOSED BETWEEN THE PUMP AND CLOSED CENTER SYSTEM WHEREBY A PRESSURE DROP IS DEVELOPED WHEN THE VOLUMETRIC OUTPUT OF THE PUMP IS GREATER THAN THE FLUID FLOW THROUGH THE ORIFICE; AND MEANS RESPONSIVE TO THE PRESSURE DROP ACROSS THE ORFICE TO COMMUNICATE THE PUMP WITH THE OPEN CENTER SYSTEM THROUGH SAID VALVE MEANS WHEREIN THE PHYSICAL AREA OF COMMUNICATION IS A DIRECT FUNCTION OF THE MAGNITUDE OF THE PRESSURE DROP ACROSS THE ORIFICE WHEREBY THE VOLUME OF FLUID FLOW THROUGH THE ORIFICE IS MAINTAINED RELATIVELY CONSTANT.
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) | 1967-08-04 | 1968-02-03 | 1968-08-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1971-08-04 | 1972-02-03 | 1972-08-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1975-08-04 | 1976-02-03 | 1976-08-04 | $7700.00 | Window Closed / Lapsed |