Control valve assembly with mechanical feedback

Claim 2

A control valve assembly for selectively controlling a flow of actuating fluid to a controlled device, said assembly having, in combInation: a spool valve assembly having a first housing formed with a bore opening through one side of said housing, a spool slidable in said bore, means on said spool and in said bore for controlling the flow of actuating fluid in accordance with the position of the spool along the bore, a pair of fluid chambers in said housing at the opposite ends of said spool, means for supplying fluid under pressure to said chambers to urge the spool in opposite directions along the bore and to hold the spool stationary in a selected neutral position when the opposed forces are balanced, and a flow passage leading from each of said chambers; a pilot valve assembly having a second housing removably mounted on said one side of said first housing and overlying the open end of said bore, a cavity in said second housing, opposed nozzles opening into said cavity and communicating with said flow passages to receive pressure fluid therefrom and direct the fluid into the cavity as opposed jets, a flapper disposed between said nozzles in spaced relation therewith and movable back and forth between them to variably restrict said nozzles and thereby vary the pressures in said chambers, and actuating means for urging the flapper toward either nozzle with a selected, variable force, said flapper moving toward and away from said open bore end in moving between said nozzles; and feedback means including an elongated pin slidably supported on said second housing and projecting into said bore through said open end and abutting at one end against said spool, a head on the other end of said pin, a first spring disposed between said head and one side of said flapper and holding said pin against said spool, and a second spring acting against the other side of said flapper and opposing said first spring to urge the flapper to a centered position between said nozzles when the spool is in said selected position.

Claim 3

A control valve assembly as defined in claim 1 in which said springs are coiled compression springs, and said second spring is compressed between said flapper and a device for selectively adjusting the spring force.

Claim 4

A control valve assembly as defined in claim 1 in which said means for supplying fluid to said chambers include a through bore in said spool supplied with fluid under pressure, and a plug in each end of the spool formed with a restricted orifice communicating between said through bore and the adjacent chamber.

Claim 5

A control valve assembly as defined in claim 3 further including a tubular screen extending through said through bore and supported at its ends by said plugs, said orifices opening into the interior of said screen.

Claim 6

A control valve assembly as defined in claim 1 in which said flapper is supported in said cavity by at least one torsion bar defining a pivotal axis for the flapper, said actuating means being mounted in said second housing outside said cavity at an end of said flapper outside said cavity.

Claim 7

A control valve assembly as defined in claim 5 in which said actuating means is a torque motor having an armature constituting an extension of said flapper.

Claim 8

A control valve assembly for selectively controlling a flow of actuating fluid to a controlled device, said assembly having, in combination: a spool valve assembly having a first housing formed with a bore having one end adjacent one side of the housing, a spool slidable in said bore, means for controlling the flow of actuating fluid in accordance with the position of the spool along the bore, and means for applying fluid pressure to opposed surfaces of said spool to urge the latter in opposite directions along said bore and to hold the spool stationary in a selected position when the opposed forces on the spool are balanced, said pressure-applying means including first and second pressure chambers in which said opposed surfaces are exposed; a pilot valve assembly having a second housing mounted on said one side of said first housing, a cavity in said second housing, first and second opposed nozzles opening into said cavity, first and second connecting passages communicating between said chambers and said nozzles, a flapper movably supported between said nozzles to variably restrict fluid flows through the nozzles and thereby vary the pressures in said chambers, and actuating means for urging said flapper toward a selected nozzle with a selected force; and feedback means including an elongaged pin slidably supported adjacent said one end of said bore and projecting into the latter into abutting engagement with said spool, a first spring in said second housing compressed between one side of said flapper and said pin and holding the pin in engagement with the spool, and a second spring compressed against the opposite side of said flapper to oppose the force of said first spring on the flapper, whereby the flapper is held in a selected position between said nozzles when said spool is in its selected position, and movement of said flapper out of its selected position by said actuating means changes the position of said spool, and, through said feedback pin, adjusts the force of said first spring.

Claim 9

A control valve assembly for selectively controlling a flow of actuating fluid to a controlled device, said assembly having, in combination: a spool valve assembly having a first housing formed with a bore having one end adjacent one side of the housing, a spool slidable in said bore, means for controlling the flow of actuating fluid in accordance with the position of the spool along the bore, and means for applying fluid pressure to opposed surfaces of said spool to urge the latter in opposite directions along said bore and to hold the spool stationary in a selected position when the opposed forces on the spool are balanced, said pressure-applying means including first and second pressure chambers in which said opposed surfaces are exposed; a pilot valve assembly having a second housing mounted on said one side of said first housing, a cavity in said second housing, first and second opposed nozzles opening into said cavity, first and second connecting passages communicating between said chambers and said nozzles, a flapper movably supported between said nozzles to variably restrict fluid flows through the nozzles and thereby vary the pressures in said chambers, and actuating means for urging said flapper toward a selected nozzle with a selected force; and feedback means including an elongaged pin slidably supported adjacent said one end of said bore and projecting into the latter into abutting engagement with said spool, a first spring in said second housing compressed between one side of said flapper and said pin and holding the pin in engagement with the spool, and a second spring compressed against the opposite side of said flapper to oppose the force of said first spring on the flapper, whereby the flapper is held in a selected position between said nozzles when said spool is in its selected position, and movement of said flapper out of its selected position by said actuating means changes the position of said spool, and, through said feedback pin, adjusts the force of said first spring.

Claim 10

A valve assembly for selectively controlling a flow of actuating fluid to a controlled device, said assembly having, in combination; a control valve having a housing and a valve spool slidable back and forth in a bore in said housing and displaceable in said bore varying distances from a selected position, said valve being operable as an incident to such displacement to vary said flow in accordance with the amount of displacement; said housing having a pressure chamber at each end of said spool, and means for delivering pressure fluid to said chambers to exert opposing forces on the spool holding the spool stationary when opposing forces on the spool are balanced, and moving the spool in a selected direction and at controlled rates when the forces are unbalanced; a pilot valve assembly supported adjacent one end of said bore and having a housing defining a chamber, a pair of spaced, opposed nozzles opening into said pilot valve chamber, a flapper centered between said nozzles in closely spaced relation therewith and supported for back and forth movement to progressively increase the resistance to flow through either one of the nozzles into said pilot valve chamber while progressively reducing the resistance to flow through the other of said nozzles, and actuating means for urging said flapper toward either nozzle with selectively variable forces; means connecting each of said nozzles to one of said control valve chambers to carry fluid therefrom to the associated nozzle, whereby said flapper variably restricts the flow of fluid under pressure through each control valve chamber to vary the pressure level therein; and a feed-back mechanism acting between said flapper and said spool and tending to return said flapper to a centered position between said nozzles in response to displacement of said spool, said feedback mechanism comprising a connecting member extending between said pilot valve assembly and said control valve and supported for back and forth movement parallel to the movement of said spool, said connecting member abutting at one end against said spool for movement therewith, a first compression spring acting between said connecting member and the adjacent side of said flapper and urging the latter in one direction toward one of said nozzles, and a second compression spring acting against the opposite side of said flapper in opposition to said first spring and counterbalancing the latter when said spool is in said selected position and said flapper is in said centered position, thereby holding the flapper yieldably in the centered position subject to movement in either direction therefrom by said actuating means and return toward the centered position by movement of said connecting member with said spool.

Claim 11

A valve assembly for selectively controlling a flow of actuating fluid to a controlled device, said assembly having, in combination; a control valve having a housing and a valve spool slidable back and forth in a bore in said housing and displaceable in said bore varying distances from a selected position, said valve being operable as an incident to such displacement to vary said flow in accordance with the amount of displacement; said housing having a pressure chamber at each end of said spool, and means for delivering pressure fluid to said chambers to exert opposing forces on the spool holding the spool stationary when opposing forces on the spool are balanced, and moving the spool in a selected direction and at controlled rates when the forces are unbalanced; a pilot valve assembly supported adjacent one end of said bore and having a housing defining a chamber, a pair of spaced, opposed nozzles opening into said pilot valve chamber, a flapper centered between said nozzles in closely spaced relation therewith and supported for back and forth movement to progressively increase the resistance to flow through either one of the nozzles into said pilot valve chamber while progressively reducing the resistance to flow through the other of said nozzles, and actuating means for urging said flapper toward either nozzle with selectively variable forces; means connecting each of said nozzles to one of said control valve chambers to carry fluid therefrom to the associated nozzle, whereby said flapper variably restricts the flow of fluid under pressure through each control valve chamber to vary the pressure level therein; and a feed-back mechanism acting between said flapper and said spool and tending to return said flapper to a centered position between said nozzles in response to displacement of said spool, said feedback mechanism comprising a connecting member extending between said pilot valve assembly and said control valve and supported for back and forth movement parallel to the movement of said spool, said connecting member abutting at one end against said spool for movement therewith, a first compression spring acting between said connecting member and the adjacent side of said flapper and urging the latter in one direction toward one of said nozzles, and a second compression spring acting against the opposite side of said flapper in opposition to said first spring and counterbalancing the latter when said spool is in said selected position and said flapper is in said centered position, thereby holding the flapper yieldably in the centered position subject to movement in either direction therefrom by said actuating means and return toward the centered position by movement of said connecting member with said spool.

Claim 12

A control valve assembly for selectively controlling a flow of actuating fluid to a controlled device, saId assembly having in combination: a valve assembly having a valve member reciprocable along a predetermined path, means for varying the flow of actuating fluid in accordance with the position of the valve member along said path, and means for applying fluid pressure to opposed surfaces of said valve member to urge it in opposite directions along said path and to hold it stationary when the opposed forces on the valve member are balanced, said pressure-applying means including two pressure chambers in which said opposed surfaces are exposed; a pilot valve assembly having a pair of orifices each connected to one of said chambers to receive pressure fluid therefrom, flapper means for variably restricting the flows of pressure fluid through said orifices from said chambers and thereby controlling the pressures in said chambers, and actuating means for selectively urging said flapper means toward a selected orifice to increase the pressure in the associated chamber in accordance with the force with which the flapper means is urged toward the orifice; and a feedback mechanism including a pin slidably supported for reciprocation parallel to said path and movable back and forth by the valve member, and spring means yieldably urging said flapper means to a selected position relative to said orifices, said pin being connected to said spring means to vary the force of the spring means in accordance with changes in the position of the valve member.

Claim 13

A control valve assembly for selectively controlling a flow of actuating fluid to a controlled device, saId assembly having in combination: a valve assembly having a valve member reciprocable along a predetermined path, means for varying the flow of actuating fluid in accordance with the position of the valve member along said path, and means for applying fluid pressure to opposed surfaces of said valve member to urge it in opposite directions along said path and to hold it stationary when the opposed forces on the valve member are balanced, said pressure-applying means including two pressure chambers in which said opposed surfaces are exposed; a pilot valve assembly having a pair of orifices each connected to one of said chambers to receive pressure fluid therefrom, flapper means for variably restricting the flows of pressure fluid through said orifices from said chambers and thereby controlling the pressures in said chambers, and actuating means for selectively urging said flapper means toward a selected orifice to increase the pressure in the associated chamber in accordance with the force with which the flapper means is urged toward the orifice; and a feedback mechanism including a pin slidably supported for reciprocation parallel to said path and movable back and forth by the valve member, and spring means yieldably urging said flapper means to a selected position relative to said orifices, said pin being connected to said spring means to vary the force of the spring means in accordance with changes in the position of the valve member.

Claim 14

A control valve assembly as defined in claim 9 in which said spring means comprise coiled compression springs acting on opposite sides of said flapper, one of said springs being compressed between said pin and said flapper to increase its force in one direction of movement of the pin and decrease its force in the other direction.

Claim 15

A control valve assembly as defined in claim 9 in which said pin is supported and movably retained on said pilot valve assembly and projects into said valve assembly into abutting engagement with said valve member.

Claim 16

A control valve assembly as defined in claim 11 in which said valve assembly has a bore with an open end on one side, and said pilot valve assembly is removably mounted on said one side with said pin projecting into said bore into engagement with the adjacent end of said valve member.

Claim 17

A controller assembly having, in combination: a piston assembly having piston means therein mounted for back and forth reciprocation, and means for applying fluid pressure to opposed surfaces of said piston means to urge the latter in opposite directions and to hold the piston means stationary when the opposed forces thereon are balanced, said pressure-applying means including two pressure chambers in which said opposed surfaces are exposed; a pilot valve assembly having a pair of orifices each connected to one of said chambers to receive pressure fluid therefrom, flapper means for variably restricting the flows of pressure fluid through said orifices from said chambers and thereby controlling the pressures in said chambers, and actuating means for selectively urging said flapper means toward a selected orifice to increase the pressure in the associated chamber in accordance with the force with which the flapper means is urged toward the orifice; feedback mechanism including a pin slidably mounted for back and forth reciprocation by said piston means, longitudinally thereof, and spring means yieldably urging said flapper means toward a selected position relative to said orifices, said pin being connected between said spring means and said piston means to vary the force of the spring means in accordance with the position of said piston means; and means responsive to changes in the position of said piston means for accomplishing a variable control function.

Claim 18

A controller assembly having, in combination: a piston assembly having piston means therein mounted for back and forth reciprocation, and means for applying fluid pressure to opposed surfaces of said piston means to urge the latter in opposite directions and to hold the piston means stationary when the opposed forces thereon are balanced, said pressure-applying means including two pressure chambers in which said opposed surfaces are exposed; a pilot valve assembly having a pair of orifices each connected to one of said chambers to receive pressure fluid therefrom, flapper means for variably restricting the flows of pressure fluid through said orifices from said chambers and thereby controlling the pressures in said chambers, and actuating means for selectively urging said flapper means toward a selected orifice to increase the pressure in the associated chamber in accordance with the force with which the flapper means is urged toward the orifice; feedback mechanism including a pin slidably mounted for back and forth reciprocation by said piston means, longitudinally thereof, and spring means yieldably urging said flapper means toward a selected position relative to said orifices, said pin being connected between said spring means and said piston means to vary the force of the spring means in accordance with the position of said piston means; and means responsive to changes in the position of said piston means for accomplishing a variable control function.

Claim 19

A controller assembly as defined in claim 13 in which said spring means are first and second opposed springs disposed on opposite sides of said flapper means to urge the latter toward said selected position, and said pin acts between said piston means and one of said springs to vary the force thereof in accordance with the position of said piston means.

Claim 20

A controller assembly as defined in claim 14 in which said spring means also include a device for selectively adjusting the force of the other of said springs.

Claim 21

A controller assembly as defined in claim 13 in which said pilot valve assembly is mounted on one end of said piston assembly with said pin extending between said assemblies and engageable with an end of said piston means for longitudinal movement by said piston means, said flapper means extending transversely of said pin, and said spring means comprising a first compression spring disposed between said pin and one side of said flapper means, and a second compression spring on the other side of said flapper means opposing said first spring.

Claim 22

A controller assembly as defined in claim 16 in which said pilot valve assembly is detachably mounted on said pilot valve assembly, and said pin is slidably mounted in said pilot valve assembly to project from one side thereof toward the piston assembly, said pin having means thereon for retaining it on the pilot valve assembly when the latter is detached.