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US 6,585,004 B1Granted
Multi-stage flow control
AssigneeDelaware Capital Formation, Inc.
InventorDon B. Porter
Life of this patent
Estimating the term…
Abstract
Disclosed is system for controlling a dynamic hydraulic component, such as a hydraulic actuator or motor. The system allows for either zero, restricted or full fluid flow to the hydraulic component. This enables either no movement, slow, precise movements, or rapid, major movements of the component. The functionality of the system is accomplished using a multi-pilot system acting on a spool valve that has a pilot piston and at least one stop piston. The stop piston(s) can move to limit the movement of the pilot piston.
Claims27
A multi-piston spool valve assembly comprising:
- a spool translatable within a ported body, wherein when said spool is in a first position, a land of said spool completely obstructs a first port of said body, wherein when said spool is in a second position, said land only partially obstructs said first port, and wherein when said spool is in a third position, said first port is unobstructed by said land;
- a movable pilot piston operatively connected to said spool whereby movement of said pilot piston can cause a movement of said spool;
- a movable stop piston that can be positioned to create a limit to the movement of said pilot piston;
- a first fluid chamber, wherein said chamber is capable of being connected to a source of pressurized fluid and is operatively connected to said pilot piston whereby when pressurized fluid is within said chamber, said fluid can cause pressure to be applied to said pilot piston;
- a second fluid chamber, wherein said second fluid chamber is capable of being connected to a source of pressurized fluid and is operatively connected to said stop piston whereby when pressurized fluid is within said second fluid chamber, said fluid can cause pressure to be applied to said stop piston;
- wherein when said spool is in said first position and pressurized fluid is directed into said first fluid chamber but is not directed to said second fluid chamber, said fluid in said first fluid chamber will cause the pilot piston to move and thereby cause said spool to move to said third position;
- and
- wherein when said spool is in said first position and pressurized fluid is directed into both of said first and second fluid chambers, pressurized fluid in said first fluid chamber will cause the pilot piston to move in a first direction and cause a movement of said spool while pressurized fluid in said second fluid chamber will cause the stop piston to be located at a position where it prevents the pilot piston from moving a maximum distance whereby said pilot piston will only be capable of moving said spool to said second position.
5 more elements
A multi-piston spool valve assembly comprising:
- a spool translatable within a ported body, wherein when said spool is in a first position, a land of said spool completely obstructs a first port of said body, wherein when said spool is in a second position, said land only partially obstructs said first port, and wherein when said spool is in a third position, said first port is unobstructed by said land;
- first and second piston assemblies operatively connected to opposite ends of said spool, wherein each of said piston assemblies comprises:
- a movable pilot piston operatively connected to said spool whereby movement of said pilot piston can cause a movement of said spool;
- a movable stop piston that can be positioned to create a limit to the movement of said pilot piston;
- a first fluid chamber that incorporates a portion of said pilot piston and is capable of being connected to a source of pressurized fluid;
- and a second fluid chamber that incorporates a portion of said stop piston and is capable of being connected to a source of pressurized fluid;
- wherein when said spool is in said first position and pressurized fluid is directed into said first fluid chamber of said first piston assembly but is not directed to said second fluid chamber of said first piston assembly nor into said first and second fluid chambers of said second piston assembly, said pressurized fluid will cause the pilot piston of said first piston assembly to move in a first direction and thereby cause said spool to move to said third position;
- and
- wherein when said spool is in said first position and pressurized fluid is directed into both of said first and second fluid chambers of said first piston assembly but not into the first and second fluid chambers of the second piston assembly, said fluid will cause the pilot piston of the first piston assembly to move in said first direction and cause a movement of said spool while pressurized fluid in said second fluid chamber of said first piston assembly will cause the stop piston of said first piston assembly to be located in a position where it prevents the pilot piston of said first piston assembly from moving a maximum distance, whereby said pilot piston of said first piston assembly will only be capable of moving said spool to said second position.
6 more elements
A multi-piston spool valve assembly comprising:
- a spool translatable within a ported body, wherein when said spool is in a first position, a land of said spool completely obstructs a first port of said body, wherein when said spool is in a second position, said land only partially obstructs said first port, and wherein when said spool is in a third position, said first port is unobstructed by said land;
- first, second and third fluid chambers that are each capable of being connected to a source of pressurized fluid;
- a movable pilot piston operatively connected to said first fluid chamber and to said spool whereby movement of said pilot piston can cause a movement of said spool;
- a first movable stop piston that is operatively connected to said second fluid chamber and can be positioned to create a limit to the movement of said pilot piston;
- a second movable stop piston that is operatively connected to said third fluid chamber and can be positioned to create a limit to the movement of said pilot piston;
- wherein when said spool is in said first position and pressurized fluid is directed into said first fluid chamber but is not directed to said second and third fluid chambers, said fluid will cause the pilot piston to move to a maximum extent and thereby cause said spool to move to said third position;
- and
- wherein when said spool is in said first position and pressurized fluid is directed into both of said first and second fluid chambers but not into said third fluid chamber, pressurized fluid in said first fluid chamber will cause the pilot piston to move in a first direction and cause a movement of said spool while pressurized fluid in said second fluid chamber will cause the first stop piston to be located in a position where it prevents the pilot piston from moving a maximum distance, whereby said pilot piston will only be capable of moving said spool to said second position.
5 more elements
A multi-piston spool valve assembly comprising:
- a spool translatable within a ported body, wherein when said spool is in a first position, a land of said spool completely obstructs a first port of said body, wherein when said spool is in a second position, said land only partially obstructs said first port, and wherein when said spool is in a third position, said first port is unobstructed by said land;
- a movable pilot piston operatively connected to said spool whereby movement of said pilot piston can cause a movement of said spool;
- a movable stop piston that can be positioned to create a limit to the movement of said pilot piston;
- a first force applicator that when actuated is capable of applying a force on said pilot piston that causes a movement of said pilot piston;
- a second force applicator that when actuated is capable of applying a force on said stop piston that causes a movement of said stop piston;
- wherein when said spool is in said first position and then said first force applicator is actuated but said second force applicator is not actuated, said pilot piston will move and thereby cause said spool to move to said third position;
- and
- wherein when said spool is in said first position and then both of said first and second force applicators are actuated, said pilot piston moves and causes a movement of said spool while said stop piston moves to a position where it prevents the pilot piston from moving a maximum distance whereby said pilot piston will only be capable of moving said spool to said second position.
5 more elements
A fluid control system comprising:
- a spool valve assembly, wherein said spool valve assembly comprises a piston assembly and a spool translatable within a ported sleeve, wherein when said spool is in a first position, a land of said spool completely covers a first port of said sleeve, wherein when said spool is in a second position, said land only partially covers said first port, and wherein when said spool is in a third position, said land does not cover said first port;
- wherein said piston assembly of said spool valve assembly comprises:
- a movable pilot piston operatively connected to said spool whereby movement of said pilot piston can cause a movement of said spool;
- a movable stop piston that can be positioned to limit the movement of said pilot piston;
- a first fluid chamber that is capable of being connected to a source of pressurized fluid and that is operatively connected to said pilot piston whereby when pressurized fluid is within said chamber, said fluid can cause pressure to be applied to said pilot piston;
- a second fluid chamber that is capable of being connected to a source of pressurized fluid and that is operatively connected to said stop piston whereby when pressurized fluid is within said chamber, said fluid can cause pressure to be applied to said stop piston;
- wherein when said spool is in said first position and pressurized fluid is directed into said first fluid chamber but is not directed to said second fluid chamber, said fluid will cause the pilot piston to move and thereby cause said spool to move to said third position;
- and wherein when said spool is in said first position and pressurized fluid is directed into both of said first and second fluid chambers, pressurized fluid in said first fluid chamber will cause the pilot piston to move in a first direction while pressurized fluid in said second fluid chamber will cause the stop piston to move to a position where it prevents the pilot piston from moving a maximum distance whereby said spool will be moved to said second position;
- a first pilot valve that is operatively connected to said spool valve assembly and is thereby capable of directing pressurized fluid into said first fluid chamber;
- a second pilot valve that is operatively connected to said spool valve assembly and is thereby capable of directing pressurized fluid into said second fluid chamber;
- a first fluid line connected to said first port;
- a second fluid line connected to a second port of said valve assembly;
- and
- wherein when a load is connected to one of said fluid lines and a source of pressurized fluid is connected to the other of said fluid lines and said land does not cover said first port, pressurized fluid from said source of pressurized fluid can travel between said first and second ports and to said load.
11 more elements
A fluid control system comprising:
- a spool valve assembly, wherein said spool valve assembly comprises first and second piston assemblies operatively connected to opposite ends of a spool translatable within a ported body, wherein when said spool is in a first position, a land of said spool completely covers a first port of said body, wherein when said spool is in a second position, said land only partially covers said first port, and wherein when said spool is in a third position, said land does not cover said first port;
- wherein each of said piston assemblies of said spool valve assembly comprises:
- a movable pilot piston operatively connected to said spool whereby movement of said pilot piston can cause a movement of said spool;
- a movable stop piston that can be positioned to limit the movement of said pilot piston;
- a first fluid chamber operatively connected to said pilot piston and capable of being connected to a source of pressurized fluid;
- a second fluid chamber operatively connected to said stop piston and capable of being connected to a source of pressurized fluid;
- wherein when said spool is in said first position and pressurized fluid is directed into said first fluid chamber but is not directed to said second fluid chamber, said fluid will cause the pilot piston to move and thereby cause said spool to move to said third position;
- and wherein when said spool is in said first position and pressurized fluid is directed into both of said first and second fluid chambers, pressurized fluid in said first fluid chamber will cause the pilot piston to move in a first direction while pressurized fluid in said second fluid chamber will cause the stop piston to move to a position where it prevents the pilot piston from moving a maximum distance whereby movement of said pilot piston will cause said spool to move to said second position;
- a first solenoid-operated pilot valve that is operatively connected to said spool valve assembly and is thereby capable of directing pressurized fluid into said first fluid chamber of said first piston assembly;
- a second solenoid-operated pilot valve that is operatively connected to said spool valve assembly and is thereby capable of directing pressurized fluid into said first fluid chamber of said second piston assembly;
- a third solenoid-operated pilot valve that is operatively connected to said spool valve assembly and is thereby capable of directing pressurized fluid into said second fluid chamber of both of said first and second piston assemblies;
- a first fluid line connected to said first port;
- a second fluid line connected to a second port of said valve assembly;
- and
- wherein when a load is connected to one of said fluid lines and a source of pressurized fluid is connected to the other of said fluid lines and said land does not cover said first port, pressurized fluid from said source of pressurized fluid can travel between said first and second ports and to said load.
12 more elements
Dependencies are inferred from the claim text.