Pressure regulating valve with flow control

Claim 2

A pressure and flow regulating valve assembly, comprising in combination housing structure enclosing a passage, overal structure forming a control valve dividing the passage, with an output chamber on one side of the valve for containing fluid under a controlled output pressure and a supply chamber on the other side of the valve for containing fluid at a supply pressure derived from a pressure source and differing always in the same direction from the controlled output pressure, flow control structure forming a flow control chamber interposed between the valve and the output chamber, with a flow limiting orifice of limited effective size connecting the flow control chamber and the output chamber to equalize the pressures therein when the valve is closed, flow through the valve producing a pressure difference across the orifice, means for controlling the output pressure comprising control means for exerting on the valve structure a variable control force tending to operate the valve in one direction, and balancing means responsive to variations in the output pressure for exerting on the valve structure a balancing force which opposes and normally balances said control force to establish an equilibrium value of the output pressure corresponding to the control force, the last said means comprising surface areas that are exposed to the fluid pressures in the output chamber and in the flow control chamber, respectively, said surface areas being movable in response to such pressures and being coupled to the valve structure to jointly exert thereon said balancing force, departure of the output pressure from such equilibrium value in a direction away from the supply pressure causing the valve to open and to reestablish equilibrium at a rate that is modulated by the flow control orifice.

Claim 3

A valve assembly as defined in claim 1, and in which said flow control structure includes formations defining said orifice and movable in response to valve operation to vary the effective size of the orifice.

Claim 4

A valve assembly as defined in claim 1, and in which said flow control structure includes structure defining an orifice of predetermined effective size when the valve is closed, said structure being coupled to the valve for increasing the effective size of the orifice in response to opening movement of the valve.

Claim 5

A valve assembly as defined in claim 1, and including also structure forming a second control valve between said output chamber and a second supply chamber for containing fluid at a supply pressure that is derived from a second pressure source that differs always in the opposite direction from the controlled output pressure, the second said valve forming structure being responsive to said control force and to the output pressure and acting to open the second valve in response to departure of the output pressure from said equilibrium value in a direction away from the second supply pressure.

Claim 6

In combination with a pressure regulating valve assembly that includes housing structure enclosing a passage having an axis, a poppet member axially slidable in the passage, an axially movable control member, structure forming a first valve operable in response to relative movement of the control member and the poppet member, structure forming a second valve operable in response to joint movement of the control member and the poppet member relative to the housing, structure forming an output chamber for containing fluid under a controlled output pressure and communicating with one side of each of the valves, conduit structure for supplying a supply pressure lower than the controlled pressure to the other side of The first valve and for supplying a supply pressure higher than the controlled pressure to the other side of the second valve, means for exerting a yielding axial control force on the control member in a direction tending to close the first valve and to open the second valve, and means for developing a balancing hydrostatic force corresponding to pressure derived from the output chamber for opposing the control force and normally maintaining an equilibrium value of the output pressure; structure forming a flow control chamber that is interposed between one of the valves and the output chamber, such structure including coaxial piston and cylinder structures that are relatively movable in response to operation of said one valve, and structure forming a flow control orifice of limited effective size connecting the flow control chamber and the output chamber, flow through said one valve producing a pressure difference across the orifice, the flow control chamber and the output chamber including respective wall portions that move axially with one of said piston and cylinder structures and with the control member at least during operation of said one valve, and develop hydrostatic forces that jointly produce said balancing force, whereby flow through said one valve causes said balancing force to vary in a direction tending to close the valve.

Claim 7

In combination with a pressure regulating valve assembly that includes housing structure enclosing a passage having an axis, a poppet member axially slidable in the passage, an axially movable control member, structure forming a first valve operable in response to relative movement of the control member and the poppet member, structure forming a second valve operable in response to joint movement of the control member and the poppet member relative to the housing, structure forming an output chamber for containing fluid under a controlled output pressure and communicating with one side of each of the valves, conduit structure for supplying a supply pressure lower than the controlled pressure to the other side of The first valve and for supplying a supply pressure higher than the controlled pressure to the other side of the second valve, means for exerting a yielding axial control force on the control member in a direction tending to close the first valve and to open the second valve, and means for developing a balancing hydrostatic force corresponding to pressure derived from the output chamber for opposing the control force and normally maintaining an equilibrium value of the output pressure; structure forming a flow control chamber that is interposed between one of the valves and the output chamber, such structure including coaxial piston and cylinder structures that are relatively movable in response to operation of said one valve, and structure forming a flow control orifice of limited effective size connecting the flow control chamber and the output chamber, flow through said one valve producing a pressure difference across the orifice, the flow control chamber and the output chamber including respective wall portions that move axially with one of said piston and cylinder structures and with the control member at least during operation of said one valve, and develop hydrostatic forces that jointly produce said balancing force, whereby flow through said one valve causes said balancing force to vary in a direction tending to close the valve.

Claim 8

The combination defined in claim 5, and in which said one valve has a circular valve orifice with a predetermined valve radius, and the radius of said piston and cylinder structures is less than the valve radius.

Claim 9

The combination defined by claim 5, and in which said orifice forming structure includes orifice defining formations that are relatively movable in response to operation of said one valve, said formations defining a predetermined minimum orifice size when the valve is closed, and acting to increase the orifice size in response to opening movement of the valve.

Claim 10

The combination defined in claim 5, and in which said structure forming the first valve comprises mutually cooperating coaxial formations on the poppet member at one end thereof and on the control member defining a circular valve orifice having a valve radius, said orifice opening in response to axial movement of the control member away from the poppet member, said poppet member has an axial through bore with a cylindrical wall, said chamber forming structure comprises a piston slidable in the cylindrical bore and effectively coupled for axial movement with the control member, and said orifice forming structure includes an aperture in the piston that is at least partially covered by the bore wall when the valve is closed, movement of the control member away from the poppet member to open the first valve causing the aperture to be progressively less covered by the bore wall.