Multi-way directional fluid flow control valve arrangement

Abstract

In order to provide a multi-way directional fluid flow control valve arrangement which provides good control while being relatively cheap to manufacture, I use simple main valves all of which have parallel axes and all lie in a common plane, enabling me to form the main valves in a cheap manufacturing operation; the pilot valve however is more complex and has at least four connections, but because the pilot valve is smaller, this extra complexity does not make the whole valve arrangement more expensive.

I claim: .[.1. A multi-way directional fluid flow control valve arrangement for the directional control of a fluid power actuator, the arrangement comprising: 
     
        when said main valve is open..]. 12.  A multi-way directional fluid flow control valve arrangement comprising: a pilot spool valve having at least a supply connection, an exhaust connection and two control connections;   at least four pilot-controlled open/shut main valves, each main valve having a pilot connection, a valve port and an axially movable valve member which seats on the valve port to close the valve at one end of the travel of the movable valve member, the movable valve members of all the main valves having parallel axes of movement and all main valves lying in a common plane;   duct means connecting said control connections of the pilot valve to respective said pilot connections of the main valves;   said control valve arrangement controlling a double acting ram comprising two pressure chambers, in which arrangement said four main valves provide a supply valve and an exhaust valve for each ram chamber, and wherein said pilot valve has a midposition in which said pilot valve supply connection is in communication with said pilot valve control connections, to apply fluid pressure to all four main valves to close them, the valve arrangement comprising an inlet for connection to a supply of pressure fluid, an exhaust and a working connection for each ram chamber, and said arrangement further comprising a check valve associated with said inlet for preventing back flow of fluid out of said inlet, direct connections between each said working connection and said inlet, and respective check valves in said direct connections preventing direct flow of fluid from said inlet to said working connections. .[.13. A control valve arrangement as claimed in claim 1, and further comprising an electromagnetic moving-armature actuator including means defining a space and an armature movable in said space, said pilot valve including a valve body defining a space and a movable valve member movable in said space, the former said space being sealed to the latter said space..]. .[.14. A control valve arrangement as claimed in claim 1, and having a single said pressure inlet, a single said exhaust outlet and two said working connections..]. .[.15. A control valve arrangement as claimed in claim 1, wherein in each main valve, the valve port forms the outlet of the valve, a valve seat surrounds the outlet and the inlet is outside the valve seat..]. .[.16. A control valve arrangement as claimed in claim 2, wherein the pilot valve comprises a radially thick sleeve defining therein a small diameter, cylindrical bore with no lands, and defining radial ducts leading into the bore and providing pilot valve ports for said pilot valve supply, exhaust and control connections..]. .[.17. A control valve arrangement as claimed in claim 1, wherein said housing also houses the pilot valve, wherein the pilot valve is a separable unit comprising a valve body and a valve spool therein, wherein the axis of movement of the valve spool is parallel to the axes of movements of the main valves, and wherein the pilot valve body has one axial end face sealed to said housing, all said pilot duct means passing through said end face..]. .[.18. A control valve arrangement as claimed in claim 1, wherein the pilot valve is a separable unit comprising a valve body and a valve spool therein, and wherein the valve body has one face sealed to said housing, all said pilot duct means passing through said one face..]. .[.19. A control valve arrangement as claimed in claim 18, wherein the axis of movement of the pilot valve spool is parallel to the axes of movement of the main valves, said one face of the pilot valve body being an axis end face..]. .[.20. A control valve arrangement as claimed in claim 7, wherein each of said housing parts is moulded in plastics material, said main duct means being moulded into at least one said part on that side of the resilient sheet which is remote from the pilot valve and respectively portions of said pilot duct means being moulded into a said part on the other side of the resilient sheet..]. .[.21. A control valve arrangement as claimed in claim 16, wherein an outer sleeve is fitted over said radially thick sleeve, said radially thick sleeve defines longitudinal ducts therethrough extending generally parallel to the axis of the pilot valve, said radially thick sleeve has flow connections on at least one axial end face thereof in communication with said longitudinal ducts, said radial ducts are in communication with said longitudinal ducts, and the other sleeve is imperforate at least adjacent the radially outer ends of said radial ducts..]. .[.22. A multi-way directional fluid flow control valve arrangement comprising:   a "hard spool, hard sleeve" pilot valve having at least a supply connection, an exhaust connection and two control connections, the pilot valve comprising a radially thick sleeve defining therein a small diameter, cylindrical bore with no lands, and defining radial ducts leading into the bore and providing pilot valve ports for said supply, exhaust and control connections;   at least four pilot-controlled open/shut main valves, each main valve having a pilot connection, a valve port and an axially movable valve member which seats on the valve port to close the valve at one end of the travel of the movable valve member, the movable valve members of all the main valves having parallel axes of movement and all main valves lying in a common plane; and   duct means connecting said control connections of the pilot valve to respective said pilot connections of the main valves..]. .Iadd. 23. A multi-way directional fluid flow control valve assembly for the directional control of a fluid power actuator which comprises:   a first molded housing formed with a pilot valve cavity and with four cavities, each cavity constituting a first diaphragm valve portion, said housing having an end wall defining said diaphragm valve cavity and including a plurality of orifices formed therein, said orifices including a supply orifice, an exhaust orifice and control diaphragm valve orifice in fluid flow communication with said first diaphragm valve portion;   a second molded housing formed with four cavities, each cavity constituting a second diaphragm valve portion, said housing being formed with fluid supply conduit means in fluid communication with two of said second diaphragm valve portions, said housing being formed with fluid exhaust conduit means in fluid communication with the remaining two of said second diaphragm valve portions, said housing being formed with fluid control conduit means in fluid communication with said fluid supply conduit means and said fluid exhaust conduit means;   valve seating means positioned between said first diaphragm valve portion and said second diaphragm valve portion thereby forming a diaphragm valve;   a pressure balanced spool-type valve disposed in said pilot valve cavity of said first molded housing and comprised of a spool of hard metal and a sleeve of hard metal, said spool being formed with a supply conduit means, an exhaust conduit means, and a plurality of conduit means in fluid flow communication with said diaphragm valve control orifices, said conduit means being in alignment with the respective orifices formed in said end wall of said first housing; and   means for mounting said first housing to said second housing. .Iaddend. .Iadd. 24. The fluid flow control valve as defined in claim 23 wherein said four cavities lie on a common plane. .Iaddend..Iadd. 25. The fluid flow control valve as defined in claim 24 wherein said valve seating means are mounted on a resilient sheet member disposed between said first and second housing to form a gasket. .Iaddend..Iadd. 26. The fluid flow control valve as defined in claim 23 wherein said housings are formed of a plastic material. .Iaddend. .Iadd. 27. The fluid flow control valve as defined in claim 23 wherein each of said four cavities of said second molded housing is formed with a valve port whereby axial movement of said valve seating means closes said valve port. .Iaddend..Iadd. 28. The fluid flow control valve as defined in claim 27 wherein each of said cavities of said first molded housing is defused by a frusto-conically shaped end wall. .Iaddend..Iadd. 29. The fluid flow control valve as defined in claim 28 wherein a spring is positioned within each of said cavities of said first molded housing. .Iaddend. .Iadd. 30. The fluid flow control valve as defined in claim 23 wherein said flow conduit means of said sleeve are formed with bores extending generally parallel to the axis thereof and with radially extending bores in fluid communication with said bores extending generally parallel to the axis of said spool, and further including a sleeve positioned about said spool to close said radially extending bores. .Iaddend..Iadd. 31. The fluid flow control valve as defined in claim 30 wherein said spool is provided with a land having a thickness approximately the same as said radially extending bores. .Iaddend..Iadd. 32. The fluid flow control valve as defined in claim 23 wherein said spool moves within said sleeve between two operative end positions and wherein said spool at an intermediate position between said end position closes each of said diaphragm valves. .Iaddend. .Iadd. 33. The fluid flow control valve as defined in claim 31 wherein in one end position one of said plurality of conduit means of said spool are in fluid communication with one of said two of said second diaphragm valve portions and with one of said remaining two of said second diaphragm valve portions, and wherein in the other end position the remaining conduit means of said plurality of conduit means of said spool are in fluid communication with the other one of said two of said second diaphragm valve portions and with the remaining one of said remaining two of said second diaphragm valve portions. .Iaddend. .Iadd. 34. The fluid flow control valve as defined in claim 23 wherein said exhaust orifice in said end wall of said first injection molded housing is in fluid communication with said fluid exhaust conduit means formed in said second injection molded housing. .Iaddend..Iadd. 35. The fluid flow control valve as defined in claim 23 wherein each of said cavities in said second housing is formed by a cylindrically-shaped outer wall and a cylindrically-shaped inner wall, said cylindrically-shaped inner wall forming a valve chamber, said chamber being substantially longer than the width thereof. .Iaddend..Iadd. 36. The fluid flow control valve as defined in claim 23 wherein the axis of said spool-type valve is parallel to the axis of said diaphragm valves. .Iaddend..Iadd. 37. The fluid flow control valve as defined in claim 23 wherein said housings are square-shaped and said diaphragm valve portions are formed at the corners thereof. .Iaddend..Iadd. 38. The fluid flow control valve as defined in claim 37 wherein the axis of said spool-type valve is at the intersection of diagonals of said housings. .Iaddend..Iadd. 39. The fluid flow control valve as defined in claim 23 wherein said spool and sleeve are in metal-to-metal fluid sealing engagement. .Iaddend.