US3589401A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pressure modulating valve
Assignee: Case LLC
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Filing: 1969-07-18
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Granted: 1971-06-29
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Expires: 1989-07-18
Abstract
Abstract A control valve for controlling the pressure of a fluid to a control port on a valve bore. The valve spool cooperates with the valve bore to define an axial flow path located between the inlet and return ports of the control valve and which is axially shiftable by moving the valve spool. With the valve spool in an operative position, the flow path bridges the control port so that the pressure in the control port is a function of the position of the flow path relative to the inlet and return ports.
Inventors
- 👤 Ray S Harding
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 06:07
CPC Classifications
F; F15; F15B; F15B13/00; F15B13/02; F15B13/04; Y; Y10; Y10T; Y10T137/00; Y10T137/8593; Y10T137/86493; Y10T137/86574; Y10T137/8667; Y10T137/86694
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
273 words
A control valve comprising: a housing having an axial valve bore therein, said bore having first, second and third axially spaced, circumferentially extending grooves in the wall thereof, said first and second grooves defining a first body land therebetween and said second and third grooves defining a second body land therebetween, an inlet port communicating with said first groove and adapted to be connected to a pressured fluid source, a return port communicating with said third groove and adapted to be connected to a reservoir, and a control port communicating with said second groove and adapted to be connected to a fluid operated device; a valve spool slidably received in said bore; the external periphery of said valve spool including a first control land at one end thereof and a second control land at the opposite end thereof, said first control land being positioned adjacent said first body land and said second control land being positioned adjacent said second groove in the neutral position of said valve spool, the external periphery of said valve spool and the internal surface of said valve bore defining a restricted flow path between said inlet and return ports; and means for shifting said valve spool in said bore away from sAid neutral position to move a portion of said first control land out of alignment with said first body land and to move a portion of said second control land into alignment with said second body land, the pressure at said control port varying linearly as a function that is dependent upon the distance that said second control land is moved relative to said second body land.
Claim 2
Dependent Claim
273 words
A control valve comprising: a housing having an axial valve bore therein, said bore having first, second and third axially spaced, circumferentially extending grooves in the wall thereof, said first and second grooves defining a first body land therebetween and said second and third grooves defining a second body land therebetween, an inlet port communicating with said first groove and adapted to be connected to a pressured fluid source, a return port communicating with said third groove and adapted to be connected to a reservoir, and a control port communicating with said second groove and adapted to be connected to a fluid operated device; a valve spool slidably received in said bore; the external periphery of said valve spool including a first control land at one end thereof and a second control land at the opposite end thereof, said first control land being positioned adjacent said first body land and said second control land being positioned adjacent said second groove in the neutral position of said valve spool, the external periphery of said valve spool and the internal surface of said valve bore defining a restricted flow path between said inlet and return ports; and means for shifting said valve spool in said bore away from sAid neutral position to move a portion of said first control land out of alignment with said first body land and to move a portion of said second control land into alignment with said second body land, the pressure at said control port varying linearly as a function that is dependent upon the distance that said second control land is moved relative to said second body land.
Claim 3
Dependent Claim
33 words
A control valve as defined in claim 1, in which said valve spool includes a sealing section blocking flow of fluid along said flow path when said spool is in a predetermined position.
Claim 4
Dependent Claim
97 words
A control valve as defined in claim 1, and in which said valve spool includes an enlarged sealing section having a transverse configuration corresponding to the transverse configuration of said bore for blocking flow along said path when said valve spool is in a neutral position, and wherein said control lands are reduced area lands on opposite ends of said enlarged section, said enlarged section being disposed in said second groove when said valve is moved from said neutral position to locate portions of respective ones of said reduced lands at opposite ends of said second groove.
Claim 5
Dependent Claim
42 words
A control valve as defined in claim 1, in which said control lands each have a cross-sectional area less than the cross-sectional area of said bore, said control lands having a combined length greater than the axial length of said second groove.
Claim 6
Dependent Claim
74 words
A control valve as defined in claim 1, in which said second groove has an axial length defining a first dimension and is axially spaced from said first groove by a second dimension, and in which the remote ends of said lands are spaced by an axial length at least equal to the combination of said first and second dimensions, said lands having a cross-sectional area less than the cross-sectional area of said bore.
Claim 7
Dependent Claim
76 words
A control valve as defined in claim 5, the further improvement of an enlarged sealing section on said spool, said enlarged section having said control land portions on opposite ends thereof, said control land portions each being equal in length to one of said dimensions, said enlarged section having a cross-sectional area equal to the cross-sectional area of said bore and blocking flow in said flow path when the valve spool is in a predetermined position.
Claim 8
Dependent Claim
166 words
A fluid control system as defined in claim 1, in which said second groove has a first axial dimension on said bore, said second groove has one end spaced from said first groove by a second dimension, and said second groove has an opposite end spaced from said third groove by a third dimension, the further improvement of said second and third dimensions being equal and said control lands each comprising a circular land having a constant cross-sectional area less than the cross-sectional area of said bore, said spool having an enlarged section between said lands for blocking flow along said flow path when said valve spool is in a neutral position, said enlarged section dividing said spool into land portions of equal axial length and said land portions each having a length equal to one of said second and third dimensions whereby movement of said valve spool away from a neutral position will cause a linear increase in pressure of fluid to said control device.
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) | 1974-06-28 | 1974-12-28 | 1975-06-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-28 | 1978-12-28 | 1979-06-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-28 | 1982-12-28 | 1983-06-29 | $7700.00 | Window Closed / Lapsed |