US3667504A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Zero-leakage spool valve
Assignee: Deere and Co
•
Filing: 1970-12-28
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Granted: 1972-06-06
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Expires: 1990-12-28
Abstract
Abstract A plurality of O-ring packings are mounted between ports in a spool valve bore. A valve spool is selectively shiftable in the bore for routing fluid among the ports and includes a plurality of lands, each of which, when located between a pair of ports, is seatingly engaged by one of the packings for preventing leakage between the pair of ports. Under normal operating conditions, the fluid pressures respectively existing at the pair of ports are different and this pressure differential exists across the packing. In order to prevent the packing from being dislodged from its mounting groove by fluid pressure, when the land portion is moved past the packing, a passage means located in the valve spool connects the fluid pressure at the port, away from which the land portion is moving, to the side of the packing remote from the port, to balance the pressure on the opposite sides of the packing, when the land portion is just about to move past the packing.
Inventors
- 👤 Richard Arthur Wittren
- 👤 Raymond Richard Meysenburg
- 👤 Robert Hugh Tweedy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:00
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/14; H05B41/30; H05B41/32; F; F16; F16K; F16K11/00; F16K11/02; F16K11/06; F16K11/065; F16K11/07; F16K11/0712; Y; Y10; Y10S; Y10S251/00; Y10S251/90; Y10T; Y10T137/00; Y10T137/8593; Y10T137/86493; Y10T137/86574; Y10T137/8667; Y10T137/86694; Y10T137/8671
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
178 words
A zero-leakage spool valve comprising: a valve body defining a bore having a pair of axially spaced inlet and outlet ports; a valve spool reciprocally mounted in said bore and including a land, said valve spool being shiftable between first and second positions respectively wherein said land prevents flow between said inlet and outlet ports and wherein said land meters flow between said pair of ports; seal means for preventing leakage across said land when said valve spool is in said first position, said seal meaNs including an annular groove in one of said bore and valve member and packing being located in said groove; passage means in the other of said bore and valve spool for connecting the fluid pressure at said inlet port to the side of the packing, which is remote from said inlet port, when the valve spool is in a position closely adjacent said second position; and said passage means including a plurality of annularly spaced, relatively small bores being in fluid communication with the interface between said valve spool and said bore.
Claim 2
Dependent Claim
178 words
A zero-leakage spool valve comprising: a valve body defining a bore having a pair of axially spaced inlet and outlet ports; a valve spool reciprocally mounted in said bore and including a land, said valve spool being shiftable between first and second positions respectively wherein said land prevents flow between said inlet and outlet ports and wherein said land meters flow between said pair of ports; seal means for preventing leakage across said land when said valve spool is in said first position, said seal meaNs including an annular groove in one of said bore and valve member and packing being located in said groove; passage means in the other of said bore and valve spool for connecting the fluid pressure at said inlet port to the side of the packing, which is remote from said inlet port, when the valve spool is in a position closely adjacent said second position; and said passage means including a plurality of annularly spaced, relatively small bores being in fluid communication with the interface between said valve spool and said bore.
Claim 3
Dependent Claim
57 words
The invention defined in claim 1 wherein said passage means has a cross-sectional area which is substantially larger than the cross-sectional area of the diametral clearance between said valve spool and said bore whereby the amount of fluid delivered by the passage means is controlled by the amount of clearance between the valve spool and said bore.
Claim 4
Dependent Claim
58 words
The invention defined in claim 1 wherein said plurality of bores have a combined cross-sectional area which is substantially larger than the cross-sectional area of the diametral clearance between said valve spool and said bore whereby the amount of fluid delivered by the bores is controlled by the amount of clearance between the valve spool and said bore.
Claim 5
Dependent Claim
25 words
The invention defined in claim 1 wherein said seal means is located in said bore and said passage means is located in said valve spool.
Claim 6
Dependent Claim
34 words
The invention defined in claim 4 wherein said passage means includes a plurality of radially extending, annularly spaced, relatively small bores intersected by an axially extending annular recess in the end of said land.
Claim 7
Dependent Claim
58 words
The invention defined in claim 5 wherein said plurality of bores have a combined cross-sectional area which is substantially larger than the cross-sectional area of the diametral clearance between said valve spool and said bore whereby the amount of fluid delivered by the bores is controlled by the amount of clearance between the valve spool and said bore.
Claim 8
Dependent Claim
22 words
The invention defined in claim 1 wherein the edge of the end of said land facing said outlet port is spherically chamfered.
Claim 9
Dependent Claim
195 words
A zero-leakage spool valve comprising: a valve body defining a bore having a pair of axially spaced ports respectively adapted for connection to a source of fluid pressure and a hydraulic function; a valve spool reciprocally mounted in said bore and including a land, said valve spool being shiftable between first and second positions respectively wherein said land prevents flow between said pair of ports and wherein said land portion meters flow between said pair of ports; seal means for preventing leakage across said land when said valve spool is in said first position, said seal means including an annular groove in one of said bore and land, and packing being located in said groove; passage means in the other of said bore and land for connecting the interface of the land and the bore, for connecting the fluid pressure at one of said ports to the side of the packing remote from said one port, when said valve member is in a third position axially adjacent said second position; said passage means including a plurality of annularly spaced, relatively small bores being in fluid communication with the interface between the valve spool and bore.
Claim 10
Dependent Claim
195 words
A zero-leakage spool valve comprising: a valve body defining a bore having a pair of axially spaced ports respectively adapted for connection to a source of fluid pressure and a hydraulic function; a valve spool reciprocally mounted in said bore and including a land, said valve spool being shiftable between first and second positions respectively wherein said land prevents flow between said pair of ports and wherein said land portion meters flow between said pair of ports; seal means for preventing leakage across said land when said valve spool is in said first position, said seal means including an annular groove in one of said bore and land, and packing being located in said groove; passage means in the other of said bore and land for connecting the interface of the land and the bore, for connecting the fluid pressure at one of said ports to the side of the packing remote from said one port, when said valve member is in a third position axially adjacent said second position; said passage means including a plurality of annularly spaced, relatively small bores being in fluid communication with the interface between the valve spool and bore.
Claim 11
Dependent Claim
58 words
The invention defined in claim 8 wherein the radial clearance between said bore and valve member is such as to permit fluid flow from said inlet port at a rate sufficient to slowly operate said function when said valve member is in said third position and said passage means being large enough to convey flow at said rate.
Claim 12
Dependent Claim
24 words
The invention defined in claim 8 wherein said seal means is located in said bore and said passage means is located in said land.
Claim 13
Dependent Claim
34 words
The invention defined in claim 10 wherein said passage means includes a plurality of radially extending, annularly spaced, relatively small bores intersected by an axially extending annular recess in the end of said land.
Claim 14
Dependent Claim
22 words
The invention defined in claim 8 wherein the edge of the eNd of said land facing said one port is spherically chamfered.
Claim 15
Dependent Claim
136 words
A zero-leakage spool valve comprising: a valve body defining a bore having a pair of axially spaced inlet and outlet ports; a valve spool reciprocally mounted in said bore and including a land, said valve spool being shiftable between first and second positions respectively wherein said land blocks and meters flow between the inlet and outlet ports; seal means including an annular groove in said bore and packing being positioned in the groove; passage means for connecting the fluid pressure at said inlet port to the side of the packing remote from the inlet port when the valve spool is in a position closely adjacent said second position and said passage means extending first axially then radially in the land from that end closest to the inlet port to the radially outer surface of the land.
Claim 16
Dependent Claim
136 words
A zero-leakage spool valve comprising: a valve body defining a bore having a pair of axially spaced inlet and outlet ports; a valve spool reciprocally mounted in said bore and including a land, said valve spool being shiftable between first and second positions respectively wherein said land blocks and meters flow between the inlet and outlet ports; seal means including an annular groove in said bore and packing being positioned in the groove; passage means for connecting the fluid pressure at said inlet port to the side of the packing remote from the inlet port when the valve spool is in a position closely adjacent said second position and said passage means extending first axially then radially in the land from that end closest to the inlet port to the radially outer surface of the land.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-06 | 1975-12-06 | 1976-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-06 | 1979-12-06 | 1980-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-06 | 1983-12-06 | 1984-06-06 | $7700.00 | Window Closed / Lapsed |