Fluid flow control assembly
First Claim
1. A device, comprising:
- a pilot valve responsive to a command signal for supplying a fluid at a command pressure to a pilot valve control port; and
a pilot operated spool valve having;
a body having a first connector and a second connector, each of said first connector and second connector being adapted for fluid communication with an external circuit; and
a spool disposed for sliding movement in said body, said spool having a first end portion and a second end portion opposite said first end portion, said first end portion of said spool being in fluid communication with said pilot valve control port such that said spool is urged to move in a first direction by said fluid at said command pressure, said spool being movable to control a fluid flow between said first connector and said second connector through said body proportionally to said command pressure when said fluid flow is a forward flow from said first connector to said second connector and when said fluid flow is a reverse flow from said second connector to said first connector;
said spool valve using negative feedback in the form of fluid at a feedback pressure acting on said spool in a second direction, opposite said first direction, to position said spool in conjunction with said fluid at said command pressure;
said spool valve utilizing unstable equilibrium of fluid forces to switch between controlling said forward flow and said reverse flow.
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Accused Products
Abstract
A device has been disclosed that may include a spool valve including a body having a first connector and a second connector and a spool movable relative to the body for controlling flow between the first connector and the second connector. The reversible flow control assembly further may include a pilot valve device developing a single pressure command in the form of a fluid at a command pressure. The spool valve may be responsive to the single pressure command developed in said pilot valve device to control flow between the first connector and the second connector without regard to the direction of flow. The majority of axial forces acting on the spool to position the spool relative to the body when fluid is flowing through the valve may be fluid forces.
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Citations
28 Claims
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1. A device, comprising:
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a pilot valve responsive to a command signal for supplying a fluid at a command pressure to a pilot valve control port; and a pilot operated spool valve having; a body having a first connector and a second connector, each of said first connector and second connector being adapted for fluid communication with an external circuit; and a spool disposed for sliding movement in said body, said spool having a first end portion and a second end portion opposite said first end portion, said first end portion of said spool being in fluid communication with said pilot valve control port such that said spool is urged to move in a first direction by said fluid at said command pressure, said spool being movable to control a fluid flow between said first connector and said second connector through said body proportionally to said command pressure when said fluid flow is a forward flow from said first connector to said second connector and when said fluid flow is a reverse flow from said second connector to said first connector; said spool valve using negative feedback in the form of fluid at a feedback pressure acting on said spool in a second direction, opposite said first direction, to position said spool in conjunction with said fluid at said command pressure; said spool valve utilizing unstable equilibrium of fluid forces to switch between controlling said forward flow and said reverse flow.
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2. A device, comprising:
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a pilot valve device responsive to a command signal for supplying a fluid at a command pressure to a pilot valve control port; and a pilot operated spool valve having; a body having a first connector and a second connector, each of said first connector and second connector being adapted for fluid communication with an external circuit; and a spool disposed for sliding movement in said body, said spool having a first end portion and a second end portion opposite said first end portion, said first end portion of said spool being in fluid communication with said pilot valve control port such that said spool is urged to move in a first direction by said fluid at said command pressure, said spool being movable through a first range of positions to control, proportionally to said command pressure, the flow of a fluid when the fluid is flowing through said body in a forward direction from said first connector to said second connector, said spool being movable through a second range of positions, offset from said first range of positions, to control, proportionally to said command pressure, the flow of the fluid when the fluid is flowing through said body in a reverse direction from said second connector to said first connector, a portion of said fluid flowing through said body having a feedback pressure and acting on said spool in a second direction, opposite said first direction, to position said spool in conjunction with said fluid at said command pressure, the magnitude of said feedback pressure being generated at least in part as a function of the position of said spool. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
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Specification