US3613508A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulic valve
Assignee: Eaton Corp
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Filing: 1970-07-27
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Granted: 1971-10-19
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Expires: 1990-07-27
Abstract
Abstract A manually operated spool type closed center flow control valve having two lockout check valves, one for each end of a doubleacting pressure fluid actuated motor. The valve affords precise spool metering of pressure fluid returning from either end of the motor to the hydraulic system reservoir because both lockout check valves are fully opened and maintained open prior to, and entirely independent of, any flow of fluid to or from either end of the motor. Thus fluid flowing through either of the fully open lockout check valves can in no way interfere with precise spool metering of flow through the control valve. The flow metering spool can also be positioned to afford floating movement of the motor plunger and rod in either direction in response to an applied external load.
Inventors
- 👤 Robert D Krehbiel
- 👤 Homer R Graber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 06:55
CPC Classifications
F; F15; F15B; F15B13/00; F15B13/02; F15B13/04; Y; Y10; Y10T; Y10T137/00; Y10T137/8593; Y10T137/87169; Y10T137/87233; Y10T137/87241
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
271 words
A hydraulic system flow control valve comprising: a housing having a. supply and return ports (11, 12, 13) b. two motor ports (14, 15) c. a bore for a slidable flow control spool and d. passageways (18, 23) interconnecting said ports and the spool bore; a flow control spool (25) slidable in said bore, said flow control spool having spaced grooves (26, 27, 28) therein defining lands (29, 30, 31, 32) for selectively controlling flow of pressure fluid to motor passageways (18, 23) and said return ports (12, 13); a pair of opposed lockout check valves (42, 43) respectively interposed in the motor passageways (18, 23) connecting the respective motor ports with the spool bore; a second bore (48) in the housing disposed in axial alignment with the two opposed lockout check valves, the two open ends of said second bore being respectively located adjacent said check valves; a pair of plungers (44, 45) slidable in said second bore and projectable from the opposite ends thereof to forcibly open the respective check valves, the second bore and said plungers defining between the adjacent ends of the plungers a pressure chamber (48); duct means (20) in said housing affording introduction of pressure fluid into said pressure chamber (48); Spool duct means in said flow control spool including an internal duct means within the spool affording introduction of pressure fluid into said duct means (20) and said pressure chamber (48); and said spool duct means being positioned to assure communication thereof with the supply port (11) upon communication of a motor passageway (18, 23) with the supply port via said grooves (26, 27).
Claim 2
Dependent Claim
271 words
A hydraulic system flow control valve comprising: a housing having a. supply and return ports (11, 12, 13) b. two motor ports (14, 15) c. a bore for a slidable flow control spool and d. passageways (18, 23) interconnecting said ports and the spool bore; a flow control spool (25) slidable in said bore, said flow control spool having spaced grooves (26, 27, 28) therein defining lands (29, 30, 31, 32) for selectively controlling flow of pressure fluid to motor passageways (18, 23) and said return ports (12, 13); a pair of opposed lockout check valves (42, 43) respectively interposed in the motor passageways (18, 23) connecting the respective motor ports with the spool bore; a second bore (48) in the housing disposed in axial alignment with the two opposed lockout check valves, the two open ends of said second bore being respectively located adjacent said check valves; a pair of plungers (44, 45) slidable in said second bore and projectable from the opposite ends thereof to forcibly open the respective check valves, the second bore and said plungers defining between the adjacent ends of the plungers a pressure chamber (48); duct means (20) in said housing affording introduction of pressure fluid into said pressure chamber (48); Spool duct means in said flow control spool including an internal duct means within the spool affording introduction of pressure fluid into said duct means (20) and said pressure chamber (48); and said spool duct means being positioned to assure communication thereof with the supply port (11) upon communication of a motor passageway (18, 23) with the supply port via said grooves (26, 27).
Claim 3
Dependent Claim
28 words
A valve according to claim 1 wherein said internal duct means includes check valve means (35), said check valve means being mounted to be unseated by supply pressure.
Claim 4
Dependent Claim
34 words
A valve according to claim 1 wherein said internal duct means is positioned to communicate with a return port (12, 13) and said duct means (20) when said spool is in neutral flow-blocking position.
Claim 5
Dependent Claim
45 words
A valve according to claim 1 wherein said spool (25) is movable to a float position and wherein said spool duct means is positioned to provide communication between said supply port (11) and said pressure chamber (48) when said spool is in said float position.
Claim 6
Dependent Claim
62 words
A valve according to claim 3 including a check valve controlled duct (57, 58) in each of said plungers (44, 45, 64) effective when the spool (25) is in its neutral position to afford flow of leakage fluid from the motor passageways (18, 23) into the pressure chamber (48), and to block flow of fluid from the pressure chamber into said passageways.
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) | 1974-10-18 | 1975-04-19 | 1975-10-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-18 | 1979-04-19 | 1979-10-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-18 | 1983-04-19 | 1983-10-19 | $7700.00 | Window Closed / Lapsed |