Four-way valve with blocked center

Claim 2

A valve assembly, comprising: housing means having an elongated bore extending therethrough; first and second port means formed in said housing means, each of said port means being adapted to be connected to a load or control device; third port means formed in said housing means and communicating with a central portion of said bore, said third port means being adapted to be connected to a supply of pressure fluid; first sleeve means disposed within said bore adjacent one end thereof and first mounting means radially floatably mounting said first sleeve means relative to said housing means; second sleeve means disposed within said bore adjacent the other end thereof and second mounting means radially floatably mounting said second sleeve means relative to said housing means; said first sleeve means and said housing means cooperating to define a first intermediate passage providing communication between said first port means and said bore, said second sleeve means and saId housing means cooperating to define a second intermediate passage providing communication between said second port means and said bore, said first and second intermediate passages respectively comprising first and second narrow slot-like grooves extending radialLy outward relative to said bore and communicating with said bore around substantially the complete peripheral extent thereof, said first and second slot-like grooves each having a small axial width while communicating with said bore at axially spaced locations which are a predetermined distance apart and disposed on opposite axial sides of said third port means; and valve spool means positioned within and axially shiftable relative to said bore for controlling the flow of fluid between said port means, said valve spool means including an elongated rod member disposed within said bore and having first and second annular elastomeric seal rings axially secured thereto and disposed in surrounding relationship therewith, said first and second seal rings being axially spaced apart by a distance substantially equal to said predetermined distance, and each of said seal rings having an axial thickness substantially greater than the axial width of said slot-like grooves, whereby said first and second seal rings respectively cooperate with and close the first and second slot-like grooves during shifting of the valve spool for controlling the flow of fluid between said port means.

Claim 3

A valve assembly according to claim 1, wherein said first and second sleeve means each have a stepped configuration defining a shoulder therebetween, and said housing means has first and second shoulders formed therein adjacent the opposite ends of said bore, said first and second shoulders being disposed adjacent and opposite the shoulders on said first and second sleeve means, respectively, and first and second annular rings of elastomeric material disposed within said bore in surrounding relationship to said first and second sleeve means, respectively, said rings being stationarily positioned relative to said housing means and being disposed between the opposed shoulders as formed on said housing means and the respective sleeve means for retaining the respective sleeve means relative to the housing means while permitting relative movement therebetween.

Claim 4

A four-way assembly, comprising: housing means including wall means defining a bore, said bore having first and second end portions and an intermediate center portion; first passage means formed in said housing means and communicating with the center portion of said bore; second and third passage means respectively communicating with the first and second end portions of said bore; fourth passage means communicating with said bore at a location disposed axially between said first and second passage means, and fifth passage means communicating with said bore at a location disposed axially between said first and third passage means; first and second sleeve means respectively positioned within said first and second end portions of said bore in substantially coaxial alignment with said center portion of said bore, at least a portion of said first and second sleeve means as disposed adjacent the center portion of said bore having an internal diameter substantially equal to the internal diameter of said center portion of said bore; first and second mounting means respectively connecting said first and second sleeve means to said housing means for substantially axially securing said first and second sleeve means relative to said housing means while permitting at least limited radial or angular movement of said first and second sleeve means relative to said housing means to facilitate alignment thereof with said center portion of said bore; said housing means and said first sleeve means having spaced opposed surfaces defining therebetween a first narrow slot-like passageway which extends completely around the periphery of said bore, said first slot-like passageway extending radially relative to said bore and providing communication between said bore and said fourth passage means; said housing means and said second sleeve means also having spaced opposed surfaces defining therebetween a second narrow slot-like pAssageway which extends completely around the periphery of said bore, said second passageway extending radially relative to said bore and providing communication between said bore and said fifth passage means; valve spool means positioned within and shiftable relative to said bore for controlling the flow of pressure fluid between the plurality of said passage means, said valve spool means having seal means thereon for individually isolating each of said passage means during axial shifting of said spool means; said seal means including first and second annular seal rings constructed of elastomeric material and disposed in surrounding relationship to said valve spool means, said first and second seal rings being respectively disposed for coaction with said first and second slot-like passageways and being axially spaced apart by a distance substantially equal to the axial spacing between said slot-like passageways, and said first and second seal rings respectively having axial widths at least slightly greater than the axial widths of said first and second slot-like passageways for permitting total closure of both said slot-like passageways when said valve spool means is axially shifted into a center closed position, said first and second seal rings causing each of the passage means to be individually isolated from all of the remaining passage means when said valve spool means is in said center closed position; and actuator means interconnected to said valve spool means for permitting selective axial shifting thereof into first or second operative positions disposed on opposite axial sides of said center closed position; said valve spool means in said first operative position permitting flow of fluid between said first and fourth passage means and between said third and fifth passage means due to said first seal ring being disposed in sealing engagement with said first sleeve means and said second seal ring being disposed in sealing engagement with the center portion of said bore axially between said first passage means and said second slot-like passageway; said valve spool means when in second operative position permitting flow of fluid between said first and fifth passage means and between said second and fourth passage means due to said second seal ring being disposed in sealing engagement with second sleeve means and said first seal ring being disposed in sealing engagement with the center portion of said bore axially between said first passage means and said first slot-like passageway, whereby axial shifting of said valve spool means between first and second operative positions causes said first and second seal rings to totally close said first and second slot-like passageways for individually isolating each of the passage means form all of the remaining passage means.

Claim 5

A four-way assembly, comprising: housing means including wall means defining a bore, said bore having first and second end portions and an intermediate center portion; first passage means formed in said housing means and communicating with the center portion of said bore; second and third passage means respectively communicating with the first and second end portions of said bore; fourth passage means communicating with said bore at a location disposed axially between said first and second passage means, and fifth passage means communicating with said bore at a location disposed axially between said first and third passage means; first and second sleeve means respectively positioned within said first and second end portions of said bore in substantially coaxial alignment with said center portion of said bore, at least a portion of said first and second sleeve means as disposed adjacent the center portion of said bore having an internal diameter substantially equal to the internal diameter of said center portion of said bore; first and second mounting means respectively connecting said first and second sleeve means to said housing means for substantially axially securing said first and second sleeve means relative to said housing means while permitting at least limited radial or angular movement of said first and second sleeve means relative to said housing means to facilitate alignment thereof with said center portion of said bore; said housing means and said first sleeve means having spaced opposed surfaces defining therebetween a first narrow slot-like passageway which extends completely around the periphery of said bore, said first slot-like passageway extending radially relative to said bore and providing communication between said bore and said fourth passage means; said housing means and said second sleeve means also having spaced opposed surfaces defining therebetween a second narrow slot-like pAssageway which extends completely around the periphery of said bore, said second passageway extending radially relative to said bore and providing communication between said bore and said fifth passage means; valve spool means positioned within and shiftable relative to said bore for controlling the flow of pressure fluid between the plurality of said passage means, said valve spool means having seal means thereon for individually isolating each of said passage means during axial shifting of said spool means; said seal means including first and second annular seal rings constructed of elastomeric material and disposed in surrounding relationship to said valve spool means, said first and second seal rings being respectively disposed for coaction with said first and second slot-like passageways and being axially spaced apart by a distance substantially equal to the axial spacing between said slot-like passageways, and said first and second seal rings respectively having axial widths at least slightly greater than the axial widths of said first and second slot-like passageways for permitting total closure of both said slot-like passageways when said valve spool means is axially shifted into a center closed position, said first and second seal rings causing each of the passage means to be individually isolated from all of the remaining passage means when said valve spool means is in said center closed position; and actuator means interconnected to said valve spool means for permitting selective axial shifting thereof into first or second operative positions disposed on opposite axial sides of said center closed position; said valve spool means in said first operative position permitting flow of fluid between said first and fourth passage means and between said third and fifth passage means due to said first seal ring being disposed in sealing engagement with said first sleeve means and said second seal ring being disposed in sealing engagement with the center portion of said bore axially between said first passage means and said second slot-like passageway; said valve spool means when in second operative position permitting flow of fluid between said first and fifth passage means and between said second and fourth passage means due to said second seal ring being disposed in sealing engagement with second sleeve means and said first seal ring being disposed in sealing engagement with the center portion of said bore axially between said first passage means and said first slot-like passageway, whereby axial shifting of said valve spool means between first and second operative positions causes said first and second seal rings to totally close said first and second slot-like passageways for individually isolating each of the passage means form all of the remaining passage means.

Claim 6

A valve assembly according to claim 3, wherein said third passage means comprises a port formed in the outer axial end of said second sleeve means, said port being substantially coaxially aligned with said bore, and said second passage means communicating with said bore adjacent the outer axial end of said first sleeve means.

Claim 7

A valve assembly according to claim 3, wherein said housing means includes a reduced diameter cylindrical sleeve portion provided adjacent one end thereof in coaxial alignment with and forming an extension of said bore, and said actuator means including a first portion fixedly interconnected to said valve spool means and movably disposed within said cylindrical sleeve portion of said housing means, said actuator means further including a second portion interconnected to and extending outwardly from said first portion so as to be disposed externally of and outwardly from the end of the cylindrical sleeve portion for enabling said first and second portions of said actuator means to be moved between first and second positions, whereby the actuator means causes a corresponding movement of said valve spool means between said first and second operative posItions, said first portion having a cross-sectional area substantially less than the cross sectional area of the opening defined by the cylindrical sleeve portion for defining a flow passage therebetween for preventing entrapment of pressure fluid within said cylindrical sleeve portion.

Claim 8

A valve assembly according to claim 3, wherein said valve spool means includes an elongated rod-like spool member having a diameter less than the internal diameter of the center portion of said bore for defining an annular passage therebetween for normally permitting flow of pressure fluid between the related passage means, at least one end of said spool member extending axially outwardly of said housing means for interconnection to said actuator means, said first and second elastomeric seal rings constituting the only seal rings disposed for coaction between said valve spool means and the housing means or the first and second sleeve means.

Claim 9

A valve assembly according to claim 3, wherein said first and second mounting means each includes an annular ring of elastomeric material disposed within said bore in surrounding relationship to its respective sleeve means, said ring being substantially stationarily positioned relative to said housing means.

Claim 10

A valve assembly according to claim 7, wherein said first and second sleeve means each includes a sleeve portion having a diameter smaller than the diameter of the surrounding portion of said bore for respectively defining first and second narrow axially elongated annular passages therebetween, said first annular passage providing direct communication between the fourth passage means and the first slot-like passageway, and the second annular passage providing direct communication between the fifth passage means and the second slot-like passageway.

Claim 11

A four-way valve assembly, comprising: housing means including wall means defining an elongated cylindrical bore; said housing means having first and second exhaust ports formed therein and communicating with said bore adjacent the opposite axial ends thereof; said housing means also having a fluid supply port formed therein and communicating with said bore adjacent the center portion thereof; said housing means still further having first and second load ports formed therein and communicating with said bore on opposite axial sides of said supply port, said first load port terminating in a narrow slot-like annular passageway which extends radially outwardly relative to said bore and communicates with said bore around substantially the complete peripheral extend thereof, said second load port terminating in a second narrow slot-like annular passageway substantially identical to said first slot-like passageway, said first slot-like passageway being disposed axially between said first exhaust port and said supply port, and said second slot-like passageway being axially disposed between said second exhaust port and said supply port, said first and second slot-like passageways being axially spaced a predetermined distance apart; valve spool means positioned within and shiftable relative to said elongated passageway for controlling the flow of pressure fluid between said plurality of ports, said valve spool means having seal means thereon for individually isolating each of said ports during axial shifting of said spool; said seal means consisting solely of first and second annular elastomeric seal rings axially secured to said valve spool means in surrounding relationship therewith, said seal rings being disposed in sliding and sealing engagement with the walls defining said bore and having an axial thickness greater than the axial width of said first and second slot-like passageways, said first and second seal rings being axially spaced said predetermined distance apart whereby said seal rings completely close said first and second slot-like passageways for totally isolating each of said ports from the remaining ports when the valve spool is in a closed center pOsition, said valve spool being axially shiftable into first and second operative positions disposed on opposite sides of said closed center position for permitting pressure fluid to be supplied from said supply port to said first and second load ports when said spool is in said first and second operative positions, respectively.

Claim 12

A four-way valve assembly, comprising: housing means including wall means defining an elongated cylindrical bore; said housing means having first and second exhaust ports formed therein and communicating with said bore adjacent the opposite axial ends thereof; said housing means also having a fluid supply port formed therein and communicating with said bore adjacent the center portion thereof; said housing means still further having first and second load ports formed therein and communicating with said bore on opposite axial sides of said supply port, said first load port terminating in a narrow slot-like annular passageway which extends radially outwardly relative to said bore and communicates with said bore around substantially the complete peripheral extend thereof, said second load port terminating in a second narrow slot-like annular passageway substantially identical to said first slot-like passageway, said first slot-like passageway being disposed axially between said first exhaust port and said supply port, and said second slot-like passageway being axially disposed between said second exhaust port and said supply port, said first and second slot-like passageways being axially spaced a predetermined distance apart; valve spool means positioned within and shiftable relative to said elongated passageway for controlling the flow of pressure fluid between said plurality of ports, said valve spool means having seal means thereon for individually isolating each of said ports during axial shifting of said spool; said seal means consisting solely of first and second annular elastomeric seal rings axially secured to said valve spool means in surrounding relationship therewith, said seal rings being disposed in sliding and sealing engagement with the walls defining said bore and having an axial thickness greater than the axial width of said first and second slot-like passageways, said first and second seal rings being axially spaced said predetermined distance apart whereby said seal rings completely close said first and second slot-like passageways for totally isolating each of said ports from the remaining ports when the valve spool is in a closed center pOsition, said valve spool being axially shiftable into first and second operative positions disposed on opposite sides of said closed center position for permitting pressure fluid to be supplied from said supply port to said first and second load ports when said spool is in said first and second operative positions, respectively.

Claim 13

A valve assembly according to claim 9, wherein said valve spool means comprises an elongated rod-like member having an diameter less than said bore for defining an annular ring-like flow passageway for providing communication between said plurality of ports, flow of pressure fluid between said ports through said annular flow passageway being controlled solely by said first and second seal rings.

Claim 14

A valve assembly according to claim 9, wherein said housing means has a reduced diameter cylindrical sleeve portion provided adjacent one end thereof in coaxial alignment with and forming an extension of said bore, and actuator means operatively interconnected to said valve spool means for causing axial shifting thereof between said first and second operative positions, said actuator means including a guide portion slideably disposed within said cylindrical sleeve portion, said guide portion having a cross-sectional area substantially less than the area of the opening defined in said cylindrical sleeve portion for providing a flow passage therebetween, and said actuator means further including a second portion interconnected to and extending outwardly from said guide portion so as to be disposed externally of and outwardly from the end of the cylindrical sleeve portion for enabling said actuator means to be moved between said first and second operative positions.