US3612088A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Throttling draft control valve
Assignee: Deutz Allis Corp
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Filing: 1969-11-03
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Granted: 1971-10-12
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Expires: 1989-11-03
Abstract
Abstract A throttling draft control valve having a pressure control chamber with fluid pressure feedback for supplying pressurized fluid to a hydraulic actuator and releasing the pressurized fluid from the hydraulic actuator and releasing the pressurized fluid from the hydraulic actuator at a controlled rate in response to a position signal.
Inventors
- 👤 James R Mcburnett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 08:25
CPC Classifications
A; A01; A01B; A01B63/00; A01B63/02; A01B63/10; A01B63/111; A01B63/112; B; B62; B62D; B62D53/00; B62D53/04; B62D53/06; B62D53/068; Y; Y10; Y10T; Y10T137/00; Y10T137/2496; Y10T137/2559; Y10T137/2574; Y10T137/2605; Y10T137/2607; Y10T137/8593; Y10T137/87169; Y10T137/87193; Y10T137/87201
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
349 words
A draft control valve means comprising housing means defining a pressure control chamber and a cylindrical spool opening connected by a pressure feedback passage, a draft control valve including a draft control valve housing defining a spool opening and a draft control valve spool received in said spool opening, means defining a vent passage adapted for communication to sump including a pressure control valve connected between said pressure control chamber and said spool Opening of said draft control valve, a valve element of said pressure control valve resiliently connected to said draft control valve spool and biased to a closed position controlling pressure in said pressure control chamber in response to draft control valve spool position, means defining an inlet port adapted for connection to a source of pressurized fluid and an actuator port adapted for connection to a hydraulic actuator with said ports connected to said cylindrical spool opening, a throttling spool in said cylindrical spool opening defining throttling passage means in communication with said inlet port and said feedback passage, said throttling spool defining groove passage means for selective and alternative connection between said inlet port and said actuator port in response to fluid pressure in said feedback passage, means biasing said throttling spool to normally prevent communication between said inlet port and said actuator port, a restricted passaged means connected across the said throttling spool to provide limited flow between said pressure feedback passage and said actuator port, means defining a discharge passage including a discharge valve connected between said actuator port and said draft control valve, means defining bleed passage means connecting said hydraulic actuator port with said pressure control chamber including a check valve for reducing the pressure in said hydraulic pressure actuator port relative to that of the pressure control chamber, said draft control spool of said draft control valve thereby controlling the opening pressure of said pressure control valve and the pressure in said pressure control chamber and controlling the discharge pressure from said hydraulic actuator port in response to positioning of the draft control valve spool of said draft control valve.
Claim 2
Dependent Claim
349 words
A draft control valve means comprising housing means defining a pressure control chamber and a cylindrical spool opening connected by a pressure feedback passage, a draft control valve including a draft control valve housing defining a spool opening and a draft control valve spool received in said spool opening, means defining a vent passage adapted for communication to sump including a pressure control valve connected between said pressure control chamber and said spool Opening of said draft control valve, a valve element of said pressure control valve resiliently connected to said draft control valve spool and biased to a closed position controlling pressure in said pressure control chamber in response to draft control valve spool position, means defining an inlet port adapted for connection to a source of pressurized fluid and an actuator port adapted for connection to a hydraulic actuator with said ports connected to said cylindrical spool opening, a throttling spool in said cylindrical spool opening defining throttling passage means in communication with said inlet port and said feedback passage, said throttling spool defining groove passage means for selective and alternative connection between said inlet port and said actuator port in response to fluid pressure in said feedback passage, means biasing said throttling spool to normally prevent communication between said inlet port and said actuator port, a restricted passaged means connected across the said throttling spool to provide limited flow between said pressure feedback passage and said actuator port, means defining a discharge passage including a discharge valve connected between said actuator port and said draft control valve, means defining bleed passage means connecting said hydraulic actuator port with said pressure control chamber including a check valve for reducing the pressure in said hydraulic pressure actuator port relative to that of the pressure control chamber, said draft control spool of said draft control valve thereby controlling the opening pressure of said pressure control valve and the pressure in said pressure control chamber and controlling the discharge pressure from said hydraulic actuator port in response to positioning of the draft control valve spool of said draft control valve.
Claim 3
Dependent Claim
31 words
A draft control valve means as set forth in claim 1 wherein said draft control valve spool defines metering grooves for metering the flow of pressurized fluid through the discharge valve.
Claim 4
Dependent Claim
49 words
A draft control valve means as set forth in claim 1 wherein said cylindrical spool opening and said throttling spool define an actuator chamber connected to said actuator port, a check valve positioned in said cylindrical spool opening permitting unidirectional flow from said actuator chamber to said actuator port.
Claim 5
Dependent Claim
79 words
A draft control valve means as set forth in claim 1 including means defining a pilot pressure chamber connected to said pressure control chamber, a check valve in said pilot pressure chamber, a pilot pressure line connected to said pilot chamber and adapted for connection to a pump compensator, a remote hydraulic actuator, a second pilot pressure line including a second check valve to thereby permit said compensator to sense the highest load pressure of said pilot pressure lines.
Claim 6
Dependent Claim
50 words
A draft control valve means as set forth in claim 1 wherein said discharge valve includes bleed passage means transmitting pressurized fluid from said actuator port through said bleed passage means to reduce the pressure in said hydraulic actuator port to substantially the pressure level in said pressure control chamber.
Claim 7
Dependent Claim
75 words
A draft control valve means as set forth in claim 1 including a sleeve portion on said throttling spool defining a port, means defining an actuator chamber communicating with said actuator port and encircling said sleeve portion, said sleeve port normally communicating with said actuator chamber, said throttling spool shifting to close communication in response to a high pressure in the pressure feedback passage to thereby limit the peak pressure supplied to said actuator port.
Claim 8
Dependent Claim
73 words
A draft control valve means as set forth in claim 1 wherein said throttling passage means normally connects said inlet port to said feedback passage, said throttling spool defines an annular recess connecting said throttling passage means to said inlet port, said throttling spool thereby shifting in response to pressure in said feedback passage and closing communication between said inlet port and said feedback passage and limit peak pressure in said control chamber.
Claim 9
Dependent Claim
58 words
A draft control valve means as set forth in claim 1 wherein said discharge valve defines a poppet valve biased to a normally closed position whereby pressure in said actuator port opens said poppet valve to relieve pressure in said actuator port and permit fluid flow to sump when said draft control valve in in an open position.
Claim 10
Dependent Claim
70 words
A draft control valve means as set forth in claim 1 wherein said discharge valve defines a poppet valve, said draft control valve spool defines metering grooves defining a variable area orifice, said poppet valve defines a constant pressure chamber whereby said poppet valve and said draft control valve provide a predetermined flow rate for discharging fluid from said actuator port when the load is lowered by said hydraulic actuator.
Claim 11
Dependent Claim
56 words
A draft control valve means as set forth in claim 1 wherein said draft control valve spool biases said pressure control valve to a closed position to lock pressurized fluid in said pressure control chamber and blocks flow of pressurized fluid through said discharge valve thereby providing a hold position at said draft control valve means.
References Cited (Backward Citations)
US2861550A
Cited
USRE26523E
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-10-11 | 1975-04-12 | 1975-10-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-11 | 1979-04-12 | 1979-10-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-11 | 1983-04-12 | 1983-10-12 | $7700.00 | Window Closed / Lapsed |