Four-way two-position control valve

Claim 2

A remotely controllable valve system for controlling the supply of pressurized air to opposite ends of the cylinder of a servo motor to actuate the piston of the servo motor in opposite directions, comprising: a primary valve; a pilot valve; and a single source of pressurized air having branched conduit means to supply air to both of said valves; said primary valve being directly flow-connected to said conduit means and to said servo motor and being provided with passage means to supply pressurized air to and exhaust air from both ends of said cylinder; said primary valve being further provided with air-actuated means to selectively control and direct the flow of air from said conduit means to each end of said cylinder; said pilot valve being directly flow-connected to said conduit means and to the flow control means of said primary valve and being provided with passage means to supply pressurized air to and exhaust air from said primary valve to cause selective operation of the flow control means of said primary valve; said pilot valve being further provided with flow control means for the air passages therein and with solenoid means to selectively actuate said last mentioned flow control means.

Claim 3

A pilot valve for use in a remotely controllable valve system, comprising: a body containing a solenoid chamber and a valve chamber in axial alignment with each other, with a first end of said valve chamber adjacent to the solenoid chamber and a second end remote therefrom; a first port in the second end of the valve chamber adapted for flow-connection to a source of pressurized air; a second port in an intermediate portion of the valve chamber adapted for flow-connection to a primary valve to deliver air thereto and receive air therefrom; and a third port between the second port and the first end of said valve chamber to receive air from the second port and exhaust it to atmosphere; a hollow valve seat assembly mounted in the intermediate portion of the valve chamber in sealing relation therewith and provided with a first radially inwardly extending valve seat located between said first and second ports and a second radially inwardly extending valve seat located between said second and third ports; said assembly having radial apertures in its wall for flow communication with said second and third ports; a valve member mounted in the valve chamber for axial movement and having a head in the first end of the chamber and a stem extending axially through the valve seat assembly with its free end in the solenoid chamber; spring means to urge the valve member toward the solenoid chamber and the valve head into sealing engagement with the first valve seat to block the flow of pressurized air to the second port; a cylindrical boss on said stem adapted to radially engage and seal said seconD valve seat when the valve head is retracted from the first valve seat to block communication between the second and third ports; said boss being so located on said stem as to be spaced axially from said second valve seat a short distance toward the first end of the valve chamber when the valve head engages the first valve seat; and a solenoid assembly comprising a frame, a coil and an armature located in said solenoid chamber; the armature being adapted, upon actuation of the coil, to move axially and strike the free end of said valve stem to unseat the valve head for flow of pressurized air to the second port and to seat the valve boss to block the flow of air from the second port to the third port.

Claim 4

A pilot valve for use in a remotely controllable valve system, comprising: a body containing a solenoid chamber and a valve chamber in axial alignment with each other, with a first end of said valve chamber adjacent to the solenoid chamber and a second end remote therefrom; a first port in the second end of the valve chamber adapted for flow-connection to a source of pressurized air; a second port in an intermediate portion of the valve chamber adapted for flow-connection to a primary valve to deliver air thereto and receive air therefrom; and a third port between the second port and the first end of said valve chamber to receive air from the second port and exhaust it to atmosphere; a hollow valve seat assembly mounted in the intermediate portion of the valve chamber in sealing relation therewith and provided with a first radially inwardly extending valve seat located between said first and second ports and a second radially inwardly extending valve seat located between said second and third ports; said assembly having radial apertures in its wall for flow communication with said second and third ports; a valve member mounted in the valve chamber for axial movement and having a head in the first end of the chamber and a stem extending axially through the valve seat assembly with its free end in the solenoid chamber; spring means to urge the valve member toward the solenoid chamber and the valve head into sealing engagement with the first valve seat to block the flow of pressurized air to the second port; a cylindrical boss on said stem adapted to radially engage and seal said seconD valve seat when the valve head is retracted from the first valve seat to block communication between the second and third ports; said boss being so located on said stem as to be spaced axially from said second valve seat a short distance toward the first end of the valve chamber when the valve head engages the first valve seat; and a solenoid assembly comprising a frame, a coil and an armature located in said solenoid chamber; the armature being adapted, upon actuation of the coil, to move axially and strike the free end of said valve stem to unseat the valve head for flow of pressurized air to the second port and to seat the valve boss to block the flow of air from the second port to the third port.

Claim 5

A pilot valve as claimed in claim 2, said valve seat assembly being axially slidably mounted in the valve chamber and being constantly urged into endwise engagement with the frame of the solenoid assembly by the spring means acting on the valve head and by the air pressure in the second end of the valve chamber to insure predetermined dimensional relationships between the valve elements and the solenoid elements despite manufacturing tolerances in the valve body.

Claim 6

A pilot valve as claimed in claim 3, the solenoid assembly being mounted for slight axial movement against the spring and air pressure in the valve chamber to reduce the impact force of the armature striking the solenoid frame.

Claim 7

A pilot valve as claimed in claim 4, the valve seat assembly being provided with sealing rings in sliding frictional engagement with the wall of the valve chamber to absorb a portion of the impact energy of the armature striking the solenoid frame.

Claim 8

A pilot valve as claimed in claim 4, at least a portion of the end of the solenoid chamber remote from the valve chamber being formed of resilient material to serve as impact-reducing stop means for the armature and frame at the end of their return stroke.

Claim 9

A valve for controlling the supply of pressurized air to opposite ends of the cylinder of a servo motor to actuate the piston of the servo motor in opposite directions, comprising: a valve body having an elongate bore therein; a first inlet port at a first end of said bore and a second inlet port at the second end of said bore; said ports being connected to a source of pressurized air; a first outlet port adjacent to the first inlet port and located between said first inlet port and the intermediate portion of the bore; a second outlet port adjacent to the second inlet port and located between the second inlet port and the intermediate portion of the bore; said outlet ports being adapted for connection to the opposite ends of the cylinder of a servo motor to supply air to and exhaust air from the cylinder; an exhaust port located at the intermediate portion of the bore between and adjacent to the outlet ports and adapted to exhaust air from each of them to atmosphere; a first annular valve ring in the bore between the first inlet port and the first outlet port, and a second annular valve ring in the bore between the first outlet port and the exhaust port; said rings being secured to each other in fixed axially spaced and communicating relation and mounted for axial sliding movement in the bore, and being in sealing engagement with the wall of the bore; said first ring having a valve seat facing the first end of the bore, and said second ring having a valve seat facing the second end of the bore; a third annular valve ring in the bore between the exhaust port and the second outlet port, and a fourth annular valve ring in the bore between the second outlet port and the second inlet port; said third and fourth rings being secured to each other in fixed axially spaced and communicating relation and mounted for axial sliding movement in the bore, and being in sealing engagement with the wall of the being said third ring having a valve seat facing the first end of the bore, and said fourth ring having a valve seat facing the second end of the bore; a shaft mounted coaxially in the Bore for longitudinal movement therein; a first valve head fixed on the shaft in the zone of the first inlet port and having a seat facing the first ring; a second valve head fixed on the shaft in the zone of the exhaust port and having a seat facing the second ring; a third valve head fixed on the shaft in the zone of the exhaust port and having a seat facing the third ring; and a fourth valve head fixed on the shaft in the zone of the second inlet port and having a seat facing the fourth ring; the seats on each head and ring set being so constructed and arranged to engage each other in sealing relation along a circular line of contact spaced radially inward from the wall of the bore; stop means on said body to limit the travel of the first and second rings toward the second end of the bore, and stop means to limit the travel of the third and fourth rings toward the first end of the bore; the spacing of the stop means on said body, the rings, and the heads being so constructed that, when the shaft is moved to its extreme position toward the first end of the bore, the fourth head will engage the fourth ring and force it into engagement with its stop means and the second head will engage the second ring and move it away from its stop means; the engagement between said second head and second ring blocking the flow path between the first outlet port and the exhaust port to create a differential air pressure on the second ring and hold it in sealing engagement with the second head.

Claim 10

A valve for controlling the supply of pressurized air to opposite ends of the cylinder of a servo motor to actuate the piston of the servo motor in opposite directions, comprising: a valve body having an elongate bore therein; a first inlet port at a first end of said bore and a second inlet port at the second end of said bore; said ports being connected to a source of pressurized air; a first outlet port adjacent to the first inlet port and located between said first inlet port and the intermediate portion of the bore; a second outlet port adjacent to the second inlet port and located between the second inlet port and the intermediate portion of the bore; said outlet ports being adapted for connection to the opposite ends of the cylinder of a servo motor to supply air to and exhaust air from the cylinder; an exhaust port located at the intermediate portion of the bore between and adjacent to the outlet ports and adapted to exhaust air from each of them to atmosphere; a first annular valve ring in the bore between the first inlet port and the first outlet port, and a second annular valve ring in the bore between the first outlet port and the exhaust port; said rings being secured to each other in fixed axially spaced and communicating relation and mounted for axial sliding movement in the bore, and being in sealing engagement with the wall of the bore; said first ring having a valve seat facing the first end of the bore, and said second ring having a valve seat facing the second end of the bore; a third annular valve ring in the bore between the exhaust port and the second outlet port, and a fourth annular valve ring in the bore between the second outlet port and the second inlet port; said third and fourth rings being secured to each other in fixed axially spaced and communicating relation and mounted for axial sliding movement in the bore, and being in sealing engagement with the wall of the being said third ring having a valve seat facing the first end of the bore, and said fourth ring having a valve seat facing the second end of the bore; a shaft mounted coaxially in the Bore for longitudinal movement therein; a first valve head fixed on the shaft in the zone of the first inlet port and having a seat facing the first ring; a second valve head fixed on the shaft in the zone of the exhaust port and having a seat facing the second ring; a third valve head fixed on the shaft in the zone of the exhaust port and having a seat facing the third ring; and a fourth valve head fixed on the shaft in the zone of the second inlet port and having a seat facing the fourth ring; the seats on each head and ring set being so constructed and arranged to engage each other in sealing relation along a circular line of contact spaced radially inward from the wall of the bore; stop means on said body to limit the travel of the first and second rings toward the second end of the bore, and stop means to limit the travel of the third and fourth rings toward the first end of the bore; the spacing of the stop means on said body, the rings, and the heads being so constructed that, when the shaft is moved to its extreme position toward the first end of the bore, the fourth head will engage the fourth ring and force it into engagement with its stop means and the second head will engage the second ring and move it away from its stop means; the engagement between said second head and second ring blocking the flow path between the first outlet port and the exhaust port to create a differential air pressure on the second ring and hold it in sealing engagement with the second head.

Claim 11

A valve as claimed in claim 7, the seat on each valve ring comprising an axially raised annular edge extending around the radially inner margin of the ring; and the seat on each valve head comprising a generally planar annular pad of yieldable material adapted to contact the ring seat in a plane transverse to the axis of the bore.

Claim 12

A valve as claimed in claim 7, said first and fourth rings being of larger diameter than said second and third rings; said bore being of increased diameter adjacent to said first and fourth rings, thereby forming annular shoulders serving as said stop means.

Claim 13

A valve as claimed in claim 7, the mounting for said shaft comprising a first piston fixed on a first end of the shaft and slidable in sealing engagement with the first end of the bore, and a second piston fixed on the second end of the shaft and slidable in sealing engagement with the second end of the bore.

Claim 14

A valve as claimed in claim 10, said first piston being of larger diameter than said second piston; the first end of the bore having a closed end wall forming with the bore and first piston an expansible chamber and having an entry port for pressurized air; and the second end of the bore being open to atmosphere; the force of the pressurized air in the expansion chamber acting on the first piston being sufficient to cause the shaft to move toward the second end of the bore.

Claim 15

A valve as claimed in claim 11, the diameters of the pistons, rings, and heads being such that, when the shaft is at the second end of the bore and pressurized air is exhausted from the expansible chamber, the net effect of the pressurized air in the bore on the pistons, rings, and heads exposed to such pressure is a force sufficient to move the shaft back to the first end of the bore.

Claim 16

A valve comprising: a body having a bore therein with a first end and a second end; a shaft concentric with said bore and axially movable therein toward each of said ends; a first valve head fixed on a first end of said shaft adjacent to the first end of said bore; second and third valve heads fixed on said shaft intermediate its length; a fourth valve head fixed on the second end of said shaft adjacent to the second end of said bore; first and second valve rings fixed to each other and communicating to form a first ring assembly slidably mounted in said bore between the first and second heads; third and fourth valve rings fixed to each other and communicating to form a second ring assembly slidaBly mounted in said bore between the third and fourth heads; said first head and ring set and said third head and ring set being constructed to contact in sealing relation upon movement of the shaft toward the second end of said bore, and said second head and ring set and said fourth head and ring set being constructed to contact in sealing relation upon movement of the shaft toward the first end of said bore; stop means on said body to limit the travel of the first ring assembly toward the second end of the bore; stop means on said body to limit the travel of the second ring assembly toward the first end of the bore; the stop means being so arranged that, when both ring assemblies abut the stop means, the distance between the contact faces of the first and third rings will be slightly less than the distance between the contact faces of the first and third heads, and the distance between the contact faces of the second and fourth rings will be slightly less than the distance between the contact faces of the first and third heads, and the distance between the contact faces of the second and fourth rings will be slightly less than the distance between the contact faces of the second and fourth heads; said distance differential serving, when the shaft is moved toward the second end of the bore, to cause the first head to contact the first ring to solidly abut its stop means and to cause the third head to contact the third ring and move it away from its stop means so that both head and ring sets will engage accurately in sealing contact; said third ring being yieldably urged toward said third head to maintain positive sealing contact; said distance differential serving to produce the same sealing contact between the second and fourth head and ring sets upon movement of the shaft toward the first end of the bore.

Claim 17

A valve comprising: a body having a bore therein with a first end and a second end; a shaft concentric with said bore and axially movable therein toward each of said ends; a first valve head fixed on a first end of said shaft adjacent to the first end of said bore; second and third valve heads fixed on said shaft intermediate its length; a fourth valve head fixed on the second end of said shaft adjacent to the second end of said bore; first and second valve rings fixed to each other and communicating to form a first ring assembly slidably mounted in said bore between the first and second heads; third and fourth valve rings fixed to each other and communicating to form a second ring assembly slidaBly mounted in said bore between the third and fourth heads; said first head and ring set and said third head and ring set being constructed to contact in sealing relation upon movement of the shaft toward the second end of said bore, and said second head and ring set and said fourth head and ring set being constructed to contact in sealing relation upon movement of the shaft toward the first end of said bore; stop means on said body to limit the travel of the first ring assembly toward the second end of the bore; stop means on said body to limit the travel of the second ring assembly toward the first end of the bore; the stop means being so arranged that, when both ring assemblies abut the stop means, the distance between the contact faces of the first and third rings will be slightly less than the distance between the contact faces of the first and third heads, and the distance between the contact faces of the second and fourth rings will be slightly less than the distance between the contact faces of the first and third heads, and the distance between the contact faces of the second and fourth rings will be slightly less than the distance between the contact faces of the second and fourth heads; said distance differential serving, when the shaft is moved toward the second end of the bore, to cause the first head to contact the first ring to solidly abut its stop means and to cause the third head to contact the third ring and move it away from its stop means so that both head and ring sets will engage accurately in sealing contact; said third ring being yieldably urged toward said third head to maintain positive sealing contact; said distance differential serving to produce the same sealing contact between the second and fourth head and ring sets upon movement of the shaft toward the first end of the bore.

Claim 18

A valve comprising: a body having a bore therein with a first end and a second end; a shaft within said bore and axially movable therein toward each of said ends; a first valve head fixed on a first end of said shaft adjacent to the first end of said bore, and a second valve head fixed on said shaft; a first valve ring in said bore adjacent to said first head, and a second valve ring in said bore adjacent to said second head; said heads having valve seats facing toward the second end of said bore and said rings having valve seats facing toward the first end of said bore; said rings being slidably mounted in said bore; and stop means on said body to limit the travel of said first ring toward the second end of said bore; movement of said shaft toward the second end of said bore causing said first head to engage said first ring and force it against its stop means and causing said second head to engage said second ring and move it toward the second end of said bore; said second ring being subject to an air pressure differential to yieldingly hold it in sealing engagement with said second head.

Claim 19

A valve comprising: a body having a bore therein with a first end and a second end; a shaft within said bore and axially movable therein toward each of said ends; a first valve head fixed on a first end of said shaft adjacent to the first end of said bore, and a second valve head fixed on said shaft; a first valve ring in said bore adjacent to said first head, and a second valve ring in said bore adjacent to said second head; said heads having valve seats facing toward the second end of said bore and said rings having valve seats facing toward the first end of said bore; said rings being slidably mounted in said bore; and stop means on said body to limit the travel of said first ring toward the second end of said bore; movement of said shaft toward the second end of said bore causing said first head to engage said first ring and force it against its stop means and causing said second head to engage said second ring and move it toward the second end of said bore; said second ring being subject to an air pressure differential to yieldingly hold it in sealing engagement with said second head.

Claim 20

A valve as claimed in claim 14 including a piston affixed to said shaft and slidable in a cylinder, said piston adapted to move said shaft in one direction in response to increase in pressure in said cylinder, and to permit movement of said shaft in the opposite direction in response to decay of pressure therein.

Claim 21

A valve as claimed in claim 14 including a second piston affixed to said shaft and slidable in a cylinder communicating with the atmosphere.