Direction control valve having float mode

Claim 2

In a hydraulic control valve of a type including first and second identical valve assemblies, each valve assembly including a valve stem axially shiftably mounted in a valve bore means, first and second valve elements mounted on the valve stem at axially spaced locations thereof for cooperating with and controlling the flow of fluid across first and second valve seats formed by the bore means at respective locations between first and second ports thereof, respectively adapted for connection to a source of fluid pressure and a respective actuator work port, and between a third work port and a first lOcation thereof, respectively adapted for connection to a respective actuator work port and a reservoir; and the first, second and third ports and first location of the bore means of the first valve assembly being respectively connected to the first, third and second ports of the bore means of the second valve assembly, the improvement comprising: each of the first and second valve assemblies including first and second mounting means respectively connecting the first and second valve elements on the valve stem thereof such that axial movement of the first valve element in a first direction will unseat the first valve element and cause concurrent movement of the valve stem and unseating of the second valve element while movement of the valve stem in said first direction will leave the first valve element undisturbed while unseating the second valve element; first actuating means for selectively shifting said first valve elements of the first and second valve assemblies in said first direction; and second actuating means exclusive of said first actuating means, for simultaneously shifting each of the valve stems of the first and second valve assemblies in said first direction.

Claim 3

The control valve defined in claim 1 wherein said second actuating means includes first and second pistons in operative association with the respective valve stems of the first and second valve assemblies and simultaneously actuatable to effect concurrent shifting of the valve stems.

Claim 4

In a direction control valve of a type including a valve body defining identical first and second valve bore means having respective closed ends, first and second valve stems respectively axially shiftably mounted in the first and second valve bore means and each having first and second poppet valve elements mounted thereon for movement therewith towards and away from the closed ends of the bore means to respectively become unseated and seated with first and second valve seat means located at axially spaced locations in each bore in positions so located relative to connections of the bores with each other and with pressure, first control, second control and exhaust ports of the valve body that when both poppet valve elements in the first bore are unseated, the pressure and first control port are interconnected and the exhaust and second control ports are interconnected and when both poppet valve elements in the second bore means are unseated, the pressure and second control ports are interconnected and the exhaust and first control ports are interconnected, the improvement comprising: said first poppet valve elements being respectively located in the first and second bore means for movement between the closed ends of the bore means and respective connections of the latter with the pressure port, each of said first poppet valve elements being mounted on a respective valve stem by first mounting means permitting the valve stem to move relative to the associated first poppet valve element in the direction of the closed end of a respective bore means; each of said second poppet valve elements being mounted on a respective valve stem by second mounting means causing the second poppet valve elements to be shifted together with the associated valve stem when the latter is shifted towards the closed end of an associated bore means; and actuator means being in operative association with each valve stem and operable for causing concurrent movement of both valve stems in the direction of the closed ends of the first and second bore means.

Claim 5

In a direction control valve of a type including a valve body defining identical first and second valve bore means having respective closed ends, first and second valve stems respectively axially shiftably mounted in the first and second valve bore means and each having first and second poppet valve elements mounted thereon for movement therewith towards and away from the closed ends of the bore means to respectively become unseated and seated with first and second valve seat means located at axially spaced locations in each bore in positions so located relative to connections of the bores with each other and with pressure, first control, second control and exhaust ports of the valve body that when both poppet valve elements in the first bore are unseated, the pressure and first control port are interconnected and the exhaust and second control ports are interconnected and when both poppet valve elements in the second bore means are unseated, the pressure and second control ports are interconnected and the exhaust and first control ports are interconnected, the improvement comprising: said first poppet valve elements being respectively located in the first and second bore means for movement between the closed ends of the bore means and respective connections of the latter with the pressure port, each of said first poppet valve elements being mounted on a respective valve stem by first mounting means permitting the valve stem to move relative to the associated first poppet valve element in the direction of the closed end of a respective bore means; each of said second poppet valve elements being mounted on a respective valve stem by second mounting means causing the second poppet valve elements to be shifted together with the associated valve stem when the latter is shifted towards the closed end of an associated bore means; and actuator means being in operative association with each valve stem and operable for causing concurrent movement of both valve stems in the direction of the closed ends of the first and second bore means.

Claim 6

In a control valve for controlling the operation of an extensible and retractable hydraulic actuator, the valve being of a type including a valve body defining first and second valve bore means having respective closed first ends and having respective second ends in fluid communication with a fluid reservoir, each of said bore means being intersected by axially spaced supply and first and second control ports located serially in that order from the closed first ends of the bore means, a first passage means interconnecting the supply ports and adapted for connection to a source of fluid pressure, a second passage means interconnecting the first control port of the first bore means with the second control port of the second bore means and adapted for connection to a first actuator work port, a third passage means interconnecting the second control port of the first valve bore means with the first control port of the second bore means and adapted for connection to a second actuator work port, said first and second bore means each having first and second valve seat means facing the closed ends thereof and located between the supply and first control ports thereof and between the second control ports and second ends thereof, first and second valve stems respectively axially shiftably mounted in the first and second bore means, first and second poppet valve elements mounted on each of the valve stems and respectively biased towards engagement with the first and second valve seat means, each of said valve stems having a fluid passage therein having first open ends in fluid communication with the closed ends of the bore means and having second open ends adapted for fluid commumication with said reservoir, each of said first poppet valve elements having a metering orifice means therein defining sole means placing the supply ports in fluid communication with the closed end of the bore means, first and second closure means respectively axially shiftably mounted on each of said valve stems for movement between closed and open positions respectively wherein they block and connect said second open ends of the fluid passage of the valve stems from and in fluid communication with the reservoir, the improvement comprising: said first and second poppet valve elements being axially shiftably mounted on their respective valve stem; each of said first and second stems having first and second abutment means located thereon so as to respectively move away and towards engagement with respective ones of the first and second poppet valve elements when the valve stem is shifted towards the closed end of the bore in which it is mounted; and actuator means operatively associated with said first and second valve stems for causing concurrent shifting of the latter in the direction of the respective closed ends of the first and second bores so as to effect simultaneous unseating of the second poppet valve elements to thereby establish a condition adapted for simultaneously connecting both work ports of an actuator to the reservoir.

Claim 7

In a control valve for controlling the operation of an extensible and retractable hydraulic actuator, the valve being of a type including a valve body defining first and second valve bore means having respective closed first ends and having respective second ends in fluid communication with a fluid reservoir, each of said bore means being intersected by axially spaced supply and first and second control ports located serially in that order from the closed first ends of the bore means, a first passage means interconnecting the supply ports and adapted for connection to a source of fluid pressure, a second passage means interconnecting the first control port of the first bore means with the second control port of the second bore means and adapted for connection to a first actuator work port, a third passage means interconnecting the second control port of the first valve bore means with the first control port of the second bore means and adapted for connection to a second actuator work port, said first and second bore means each having first and second valve seat means facing the closed ends thereof and located between the supply and first control ports thereof and between the second control ports and second ends thereof, first and second valve stems respectively axially shiftably mounted in the first and second bore means, first and second poppet valve elements mounted on each of the valve stems and respectively biased towards engagement with the first and second valve seat means, each of said valve stems having a fluid passage therein having first open ends in fluid communication with the closed ends of the bore means and having second open ends adapted for fluid commumication with said reservoir, each of said first poppet valve elements having a metering orifice means therein defining sole means placing the supply ports in fluid communication with the closed end of the bore means, first and second closure means respectively axially shiftably mounted on each of said valve stems for movement between closed and open positions respectively wherein they block and connect said second open ends of the fluid passage of the valve stems from and in fluid communication with the reservoir, the improvement comprising: said first and second poppet valve elements being axially shiftably mounted on their respective valve stem; each of said first and second stems having first and second abutment means located thereon so as to respectively move away and towards engagement with respective ones of the first and second poppet valve elements when the valve stem is shifted towards the closed end of the bore in which it is mounted; and actuator means operatively associated with said first and second valve stems for causing concurrent shifting of the latter in the direction of the respective closed ends of the first and second bores so as to effect simultaneous unseating of the second poppet valve elements to thereby establish a condition adapted for simultaneously connecting both work ports of an actuator to the reservoir.