US3250185A - Circuit control valve instrumentality - Google Patents

Circuit control valve instrumentality Download PDF

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Publication number
US3250185A
US3250185A US35371064A US3250185A US 3250185 A US3250185 A US 3250185A US 35371064 A US35371064 A US 35371064A US 3250185 A US3250185 A US 3250185A
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United States
Prior art keywords
fluid
valve
pressure
service
passage
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English (en)
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Francis H Tennis
William N Tolbert
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Koehring Co
Hydraulic Unit Specialties Co
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Hydraulic Unit Specialties Co
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Priority to GB1050181D priority Critical patent/GB1050181A/en
Application filed by Hydraulic Unit Specialties Co filed Critical Hydraulic Unit Specialties Co
Priority to US35371064 priority patent/US3250185A/en
Priority to DEH53611A priority patent/DE1242961B/de
Priority to ES304178A priority patent/ES304178A1/es
Priority to FR990815A priority patent/FR1412072A/fr
Priority to BE654189D priority patent/BE654189A/xx
Priority to NL6503624A priority patent/NL6503624A/xx
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Publication of US3250185A publication Critical patent/US3250185A/en
Assigned to KOEHRING COMPANY, A CORP. OF DE reassignment KOEHRING COMPANY, A CORP. OF DE ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: KOEHRING COMPANY A WI CORP.
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B13/00—Details of servomotor systems ; Valves for servomotor systems
    • F15B13/01—Locking-valves or other detent i.e. load-holding devices
    • F15B13/015—Locking-valves or other detent i.e. load-holding devices using an enclosed pilot flow valve
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00—Fluid handling
    • Y10T137/8593—Systems
    • Y10T137/87169—Supply and exhaust
    • Y10T137/87233—Biased exhaust valve
    • Y10T137/87241—Biased closed

Definitions

  • control valve exercise positive control over the boom cylinder when its spool is shifted to effect lowering of the boom.
  • the pressures at the opposite sides of the cylinder are unbalanced, and the timing of the spool is such that it first connects the raise port ofthe boom cylinder with the reservoir, with the result that the boom or load tends to drop in more or less uncontrolled fashion under the force of gravity.
  • This also leads to cavitation in the lower side of the 3,250,185 Patented May 10, 1966 boom cylinder, due to expulsion of fluid from its raise port before fluid is allowed to flow into its lower port, and because the load continues to drive fluid out of the raise portfaster than the pump can supply fluid to its lower port even after the spool is fully shifted to its load lowering position.
  • Circuit control devices have been proposed in the past, as an adjunct to the conventional spool type cylinder control valves, in an effort to overcome the problems discussed above.
  • Such devices have incorporated valve mechanisms that are intended to positively lock hydraulic fluid in a cylinder without reliance upon the fit of the control spool of the cylinder control valve in its bore; to counterbalance or correlate the flow of hydraulic fluid to and from the opposite sides of the cylinder so as .to minimize the possibility of the load driving the cylinder and resulting void formation therein; and to effect cushioning of the shocks that inertia forces tend to produce when the control spool is suddenly returned to its neutral position to stop lowering or sidewise swingingmotion of a heavy load.
  • One such circuit control device is disclosed in Patent No.
  • one of the objects of the invention resides in the provision of a circuit control device of the character described featuring a pair of pressure responsive main valves, one for each port of a reversible fluid motor, wherein said main valves govern all fluid flow to and from themotor, and either can serve as a supply valve that opens solely in response to the force imposed thereon by supply fluid under pressure while the other valve serves as an exhaust valve.
  • Another purpose of this invention resides in the provision of a circuit control device of the character described featuring pilot valves that are biased toward positions closing exhaust passage means for the pressure chambers of their respective main valves by a spring force which is readily adjustable to enable compensation for line pressure losses in a system incorporating the device.
  • a further purpose of the invention resides in the provision of a circuit control device such as described, featuring a compact body in which the lockout and counterbalancinlg valve mechanisms are incorporated, and in which crossline relief mechanism may be readily incorporlated to relieve pressure shocks in a system embodying the device, without entailing objectionable enlargement of its body.
  • FIGURE 1 is a sectional view of a circuit control device embodying this invention, illustrating the same in its lockout position and diagrammatically showing how it is connected in a fluid pressure operated system including a pump, a reservoir, and a conventional motor control valve;
  • FIGURE 3 is a view similar to FIGURE 2 but illusrtrating one of the valve mechanisms in a partly open exhaust metering position.
  • the numeral 5 generally designates the circuit control device of this invention. Itis adapted to form part of a fluid pressure operated system comprising a pump. 6 having its inlet connected by a duct 7 with a fluid reservoir 8 and having its outlet connected by a duct 9 with the inlet 10 of a conventional motor control valve 11.
  • the control valve 11 has a return port 12 connected by a duct 13 with the reservoir, and it has a pair of service ports 14 and 15 in which are connected supply lines 16 and 17, respectively. These supply lines are communicable with the motor ports at the opposite sides of a reversible fluid motor, not shown.
  • the circuit control device 5 of this invention comprises a body 18 having a pair of service passages 19 and 20 therein which are respectively adapted to form continuations of the supply lines 16 and 17, and a pair of valve mechanisms 21 in the body, one for each service passage, governs fluid flow therethrough.
  • Each of the service passages 19 and 20 in the body is comprised of an inlet branch 26 and an outlet branch 27.
  • the inlet branches 26 are substantiallyL-shaped, having coplanar leg portions 28 extending inwardly from their junctions with the body inlets 22-23, and having parallel upright stem portions 29 which lie at opposite sides of a partition wall 30 in the body located substantially centrally between the ends of the body.
  • a hole 31 through the partition wall serves to slidably mount a fluid pressure responsive plunger 32, for a purpose to be later described.
  • the outlet branches 27 are also L-shaped, having coplanar leg portions 33 extending inwardly from their junctions with the motor ports 2425, and parallel downwardly extending stem portions 34 spaced outwardly from the upstanding stem portions 29 of the inlet branches and communicating therewith through short bores 35 coaxial with the hole 31 in the partition wall 30.
  • These bores open to the inner end portions or bottoms of coaxial counterbores 36, which in turn open to the stern portions of the outlet branches 27 and to the opposite ends of the body through enlarged holes that are threaded to receive plugs 37.
  • the plugs 37 thus close the outer ends of the counterbores.
  • the valve mechanisms 21 are mounted in the counterbores 36, and they are identical. Each comprises a normally closed main valve 39, a normally closed pilot valve 40, and a substantially cylindrical core member 41 which slidably supports the main valve and contains the pilot valve. At the bottom of each counterbore, the body is machined to provide a tapered annular valve seat 42., which surrounds the adjacent bore 35 and faces axially outwardly toward the counterbore and the adjacent stem 34 of the outlet branch of its service passage.
  • the flange 48 provides a stop with which the piston portion 45 of the' mainvalve engages to define the outermost or fully open position of the main valve in its counterbore, and it also serves as a spring seat against which one end of a coiled expansion spring 49 abuts.
  • the spring encircles the core member 41, extends into the interior of the annular piston portion 45 on the main valve, and engages its internal shoulder 43 so as to yieldingly hold the main valve seated.
  • each core member provides a support upon which the smaller diameter end portion of its main valve is slidingly mounted, and the joint therebetween is sealed by an O-ring 50 confined in a circumferential groove in the exterior of the core member. It also has a coaxial bore 51 through its inner end portion, that opens axially outwardly to a counterbore 52 in the core member through an annular pilot valve seat 53 at the bottom of the counterbore 52, and affords communication between the hollow interior of the core member and the inlet branch 26 of its service passage through the bore 35 thereof andthe open inner end of its main valve.
  • Each of the valve mechanisms 21 also comprises a pilot guide member 55 of tubular construction, having at its outer axial end a radially enlarged head 56 which is received in a well 57 in the adjacent plug. This head is confined axially between the bottom of the well and the flange 48 on its core member so that the guide member is held in fixed relation to the body 18.
  • the guide member also has a reduced inner end portion 58 which projects into the mouth of the counterbore 52 in the adjacent core member and which provides a bearing in which a stem 59 on the pilot valve 40 is slidably re-
  • Each pilot valve comprises a cylindrical 40' located in the counterbore of its core member, axially inwardly, of its stem and the inner end of its guide member.
  • the body is slightly larger in diameter than the stem, and
  • each of the pilot valves normally projects axially inwardly through its seat, and has a pad 64 formed on its extremity, the exterior. of which clears the wall of the bore 51 in the adjacent core member.
  • These pads are adapted to be engaged by the ends of stems 65 on the plunger 32, which project coaxially from its opposite ends into the bores 51 of the core members to have their extremities closely adjacent to the pads 64 on the pilot valves.
  • axial sliding movement of the plunger 32 in opposite directions effects opening of one or the other of the pilot valves 40.
  • the pilot valves are permitted only a small amount of opening motion off of their seats, being limited in this respect by the engagement of their slightly enlarged bodies with I the inner axial ends of the guide members therefor.
  • each core member cooperates with the wall of the counterbore in which it is located to define an annular pressure chamber or cylinder in which the piston portion 45 on each main valve operates.
  • Pressure fluid can flow into these cylinders from the outlet branches of their respective service passages and exert force on the ends and internal shoulders 43 of the main valves to hold them in their closed posit-ions.
  • Pressure fluid in the outlet branches of the service passages can also act upon the external shoulders 44 on the main valves, tending to open them.
  • each of the valve mechanisms incorporates a cylinder exhaust passage the outlet of which comprises the bore 51in its core member 41, and includes the hollow interior of the core member in which the body 40' of the pilot valve operates, and radial holes 68 in the wall of the core member surrounding the pilot valve body.' These radial holes open into the cylinder space at areas surrounded by the piston portion of each main valve, and thus provide communication between their cylinders and the inlet branches of their respective service passages at times when the pilot valves are moved outwardly away from engagement with their seats.
  • the right hand main valve 39 governing the service passage 2 0 will temporarily remain closed due to the action thereon of load pressurized fluid in its pressure chamber or cylinder, to prevent the escape of fluid from the load raising port of the boom lift cylinder.
  • the right hand main valve 39v is not allowed to open until the pressure of fluid builds up in the service passage 19 to a value such that the force it exerts on the left hand end of the plunger 32 tending to move it to the right is great enough to overcome the force of the spring 62 acting upon the pilot valve 40 of the right hand valve mechanism.
  • the plunger moves to the right and pushes the pilot valve off of its seat.
  • the main valve 39 for passage 20 then opens fully in consequence of the force which fluid under pressure in its outlet branch 27 exerts upon its external shoulder 44. Fluid in the load raising end of the boom cylinder may then exhaust to the return line.
  • Both main valves 39 are then in their fully open positions seen in FIGURE 2, and the boom accordingly begins to descend.
  • FIGURE 3 shows the right hand main valve 39 in an exhaust metering position which it can occupy during the entire descent of the boom to assure flow of pressure fluid to and from the boom lift cylinder at equal rates and thus not only control the rate of descent of the boom but to assure against drawing a void in the boom lowering side of its cylinder.
  • the right hand main valve, 39 is in a partially closed or metering position with its small diameter end portion located within the reduced bottom portion 38 of its counterbore but off of its seat 42. It will stay in a metering position such as shown as long as the load on the boom lift cylinder tends to increase the pressure in the load raising side of the cylinder and to correspondingly decrease the pressure in the load lowering side of the cylinder.
  • the position of the right hand main valve is determined by the position of its pilot valve. It is caused to move toward and from its seat more or less in correspondence with motion of its pilot valve toward and from its seat, and the main valve will assume a partially closed or metering position such as shown in FIGURE 3 whenever its pilot valve occupies a similar partially closed position.
  • exhaust fluid in the outlet branch of the .service passage 20 cannot flow freely through the pressure cham-. ber of the right hand main valve 39 when its pilot valve is in its partially closed position obstructing the outlet its internal and external surfaces.
  • the pressure of supply fluid flowing to the cylinder through the service passage 19 constitutes an accurate measure of the rate at which fluid is expelled from the cylinder and is relied upon by the flow controlling device of this invention to determine the position of the right hand main valve 39 through the action of the pressure responsive plunger 32 on its pilot valve.
  • the circuit control device of this invention thus achieves a highly desirable counterbalancing function in that it serves to correlate the flow of fluid to and from a double acting hydraulic cylinder or other fluid motor despite the fact that the load operated by the cylinder at times tends to drive the cylinder and cause expulsion of fluid from one side thereof faster than the pump can supply fluid to the other side of the cylinder.
  • valve mechanism of this invention because of the flow correlation achieved by the valve mechanism of this invention, the possibility of void formation in the cylinder ,is minimized at times when the load operated'thereby tends to cause fluid to be expelled from one side of the cylinder at a rate faster than fluid can be supplied to its other side.
  • the pilot valve springs serve as centering springs for the plunger.
  • Each main valve recloses promptly at this time due to the bias of its spring 49, and under the additional bias of load pressurized fluid that may be present in the outlet branch of its service passage.
  • reclosure of the right hand pilot valve 40 closes off the exhaust passage for the pressure chamber of its main valve, so that load pressurized fluid in the outlet branch of its service passage can flow to and be trapped in said pressure chamber and thus aid the spring 49 in reclosing the right hand main valve.
  • the crossline relief valve mechanism 72 can be of a conventional type, but have here been shown as comprising a pair of identical bi-directional fluid pressure responsive valve devices 73 such as are disclosed in the copending application of Francis H. Tennis, Serial No. 229,601, filed October 10, 1962, now Patent No. 3,194,261 and entitled Cross Line Relief Mechanism for Reversible Hydraulic Motor. They are mounted on the outlet or motor side of the body 18 to control fluid flow through a transfer passage 74 the opposite ends of which connect with the outlet branches 27 of the service passages through short bores 75.
  • this invention provides a hydraulic circuit control device that has many unique features, amongst which are a pair of pilot controlled main valves WhlCh govern all fluid flow through the service passages of the device and effect metering of exhaust flowthrough either service passage in accordance with the pressure of supplying fluid in the other service passage; provision for ad ustment of the pilot valve springs to enable compensation for line pressure losses; and utility of the device with control valves having valve spools of either the hold-in-neutral or motor types.
  • said normally high pressure value in the service (4) means providing a venting passage for each passage for said other valve, and for effecting inpressure chamber leading to the inlet branch crease in the fluid pressure closing force on its valve of its service passage through said hole in its in accordance with a decrease in the pressure of valve supporting member and the hollow interior supply fluid in the service passage for said other of the latter,
  • the circuit control means of claim 1, wherein the member normally closing said hole therein to force controlling means for each valve comprises: 15 block the venting passage for its pressure cham- A. a member that is movable in one direction from a ber;
  • pilot valve actuating means in the body responsive fluence of supply fluid at said normally high prest0 the pressure Of supply fluid in the inlet branch of sure value in the service passage for the other valve er service passage to efiect opening of the pilot to effect reduction of said closing force on its valve; ve assoc ated with the other service passage;
  • Circuit control means for use with a reversible fluid motor, and of the type comprising a body having a pair of h other valve at a pressure li h l b 1 id service passages either of which provides for flow of supno 'mal high pressure value limits spring biased ply fluid to one side Of the motor while the other provides turn of said member to said first position thereof, return how of fluid from the pp Side of The and whereby the valve associateed with said member motor: further Characterized y following! said member can occupy an intermediate position at times when supply fluid in the service passage for A.
  • each of said service pasages comprises can occupy a position intermediate its open and closed positions in correspondence with the intermediate position of said member, to meter the re- (1) an inlet branch, (2) an outlet branch having a portion laterally turn flow of fluid through its service passage. adjacent to a Portion of the inlet branch,
  • C. annular main valve seats in the body, one for each (2) a math Valve mounted on and encircling Said service passage, surrounding the bore thereof and member and constrained thereby to motion f i toward outlet branch; axially of the recess between open and closed D. counterbores in the body, one for each service Positions said math Valve having a large diam passage coaxial with and opening t0 its bore, and eter annular portion at one end slidably fitting to the Outlet branch th f; said recess and having a smaller diameter por- E.
  • valve mechanism in each counterbore comprising, at its other end normally engaging the 1 a hollow Cylindrical Valve supporting main valve seat, said valve permitting transfer fi d with respect to the body, caaxial with of fluid between the inlet and outlet branches the counterbore and cooperating therewith to P its Service Passage only
  • main Valve define an annular pressure chamber, each of said 13 Open but being adapted to open in response to members having a hole in one end opening to flow of supply fluid into the inlet branch of its h bore of its service passage to communicate Service Passage, its hollow interior with the inlet branch of its means defining a transfer Passage Communicatr i e a ing said recess with the outlet branch of its serv- (2) a tubular main valve encircling said valve supice Passage so that fluid in Said ou'dht branch porting member and mounted thereon axial at a pres-sure exceeding that of fluid in its inlet movement between open d l d position, branch can flow into the recess and act upon the said main
  • pilot valve actuating means in the body, responsive to the pressure of supply fluid in the inlet branch of either service passage to effect opening of the pilot valve associated with the other service passage;
  • Circuit control means for use with a reversible fluid motor,'and of the type comprising a body having a pair of service passages either of which provides for flow of supply fluid from a pump to one side of the motor while the other provides for return flow of fluid from the opposite side of the motor to a reservoir, further characterized by the following:
  • each service passage comprises (1) an inlet branch through which supply fluid enters the body and through Which return fluid leaves the body,
  • main valves in the body, one for'each service passage normally engaging the seat thereof, and which must be open to permit fluid to flow in either direction through its service passage, said main valves being adapted to open in response to flow of supply fluid into the inlet branches of their respective service passages to permit fluid to flow to the associated outlet branch;
  • D. means in the body defining 'a pressure chamber for each main valve, said pressure chambers having communication with the outlet branches of their respective service passages;
  • E. means on each main valve defining a piston which operates in its pressure chamber and upon which fluid in the chamber supplied thereto from the outlet branch of its associated service passage can act to hold the main valve engaged with its seat as long as the pressure of fluid in said outlet branch exceeds that of its associated inlet branch;
  • F. means in the body defining an exhaust passage for each pressure chamber to communicate the same with the inlet branch of its associated service passage;
  • G. means on each main valve providing an external surface facing'toward the associated bore and upon which fluid in the outlet branch of its service passage at a pressure exceeding that of fluid in its inlet branch can act to open the main valve at times when its pressure chamber is vented to its inlet branch through the exhaust passage for 'said pressure chamber;
  • H. a pilot valve for each main valve, normally closing the exhaust passagefor its pressure chamber and mechanically independent of its associated main valve; I t I.' and fluid pressure responsive actuating means for each pilot valve, operable in response to the pressure of supply fluid flowing into the inlet branch of either service passage to effect opening of the pilot valve associated with the other service passage, so that the main valve for said other service passage can be opened in consequence of the force exerted upon said surfacethereof by 'r'eturn'fluid' in its associated outlet branch to allow fluidto flow therefrom to the associated inlet branch.
  • circuit control means of claim 5 further characterized by:
  • said core member providing an internal support for the adjacent main valve and having a hole therein opening from its hollow interior to the associated service passage bore and cooperating with the hollow interior of the core member to define the outlet portions of the exhaust passage for the associated pressure chamber;
  • Fluid control means comprising: i A. a body having a service passage that is connectible B. an annular 'valve seat in the body surrounding the bore and facing the outlet branch of the service passage;
  • the body having a cylindrical recess therein at said side of the inlet branch, said recess opening to the outlet branch and to the bore and being coaxial with the latter;
  • D. valve mechanism in the recess to control fluid flow in either-direction from one branch to the other of the service passage comprising (1) a main valve having a portion at one end providing a piston slidably fitting the recess, and having a coaxial smaller diameter portion at its other end normally engaging the valve seat, said valve being adapted to open in response to the pressure of supply fluid flowing into the inlet branch of the service passage,
  • passage means at all times communicating said recess with the outlet branch so that fluid therefrom can flow into the recess and act upon the piston of the main valve to hold the same closed as long as the pressure of fluid in the outlet branch exceeds that of fluid in the inlet branch, (3) means defining an exhaust passage for said recess leading to the inlet branch of the service passage, and through which the recess can be vented (4) a pilot valve normally closing said exhaust passage and mechanically independent of the main valve to allow opening and closing motion E. and actuating means in the body engageable with the pilot valve, for moving the same to open position.
  • Fluid flow control means comprising: A. a body having a service passage that is connectible with a fluid motor to provide for the flow of fluid to and from the motor, said service passage having 1) an inlet branch,
  • the body having a cylindrical recess therein at said side of the inlet branch, said recess opening to the outlet branch and to the bore and being coaxial with the latter;
  • D. valve mechanism in the recess to control fluid flow in either direction from one branch to the other of the service passage comprising (1) a main valve having a tubular skirt portion at one end providing a piston slidably fitting the recess, and having a coaxial smaller diameter portion at its other end normally engaging the valve seat, said valve being adapted to open in response to the pressure of supply fluid flowing into the inlet branch of the service passage,
  • passage means at all times communicating said pressure chamber with the outlet branch so that fluid therefrom can flow into the chamber and act upon the piston of the main valve to hold the same closed as long as the pressure of fluid in the outlet branch exceeds that of fluid in the inlet branch,
  • said core member is hollow; said exhaust passage comprises the hollow interior of the core member and a hole therethrough opening to said bore; the pilot valve is mounted in the interior of the core member; and said actuating means extends through the bore and said hole in the core member for engagement with the pilot valve.
  • a circuit control device adapted for connection in the supply lines between the reversing valve and the motor to govern operation of the latter, comprising:
  • service passages that are adapted to provide parts of the supply lines employed to connect the opposite sides of a reversible fluid motor with a reversing valve therefor, said service passages respectively comprising (a) inlet branches having portions adjacent to one another and arranged at opposite 1% sides of the apertured portion of the partition wall,
  • outlet branches that are connectable with the opposite sides of a reversible fluid motor and which have portions adjacent to their respective inlet branches at the sides thereof remote from the partition wall,
  • each cylinder comprising (1) a tubular pressure responsive outer valve having a small diameter end portion which normally engages the main valve seat to block transfer of pressure fluid between the inlet and outlet branches of its service passage, said outer valve being movable off of its seat in response to flow of supply fluid into the inlet branch of its service passage, each of said outer valves having (a) a large diameter end portion providing an annular piston slidably received in its cylinder,
  • an inner valve axially movably mounted in the interior of the core member and normally engaging said inner valve seat to close the cylinder venting passage and thus enable the outer valve to be held in its seated position whenever fluid is present in the cylinder at a pressure exceeding that of fluid in the inlet branch of its service passage;
  • Circuit control means for use with a reversible fluid motor, and of the type comprising a body having a pair of service passages either of which provides for flow of supply fluid from a pump to one side of the motor while the other provides for return flow of fluid from the op posite side of the motor to a reservoir, further characterized by the following:
  • each service passage comprises (1) an inlet branch through which supply fluid enters the body and through which return fluid leaves the body,
  • main valves in the body, one for each service passage normally engaging the seat thereof, and which must be open to permit fluid to flow in either direction through its service passage, said main valves being adapted to open in response to flow of supply fluid into the inlet branches of their respective service passages to permit fluid to flow to the associated outlet branch;
  • D. means in the body defining a pressure chamber for each main valve, said pressure chambers having communication with the outlet'branches of their respective service passages;
  • each main valve defining a piston which operates in its pressure chamber and upon which fluid in the chamber supplied thereto from the outlet branch of its associated service passage can act to hold the main valve engaged with its seat as long as the pressure of fluid in said outlet branch exceeds that of fluid in its associated inlet branch;
  • F. means in the body defining an exhaust passage for each pressure chamber to communicate the same with the inlet branch of its associated service passage;
  • G. means on each main valve providing an external surface facing toward the associated bore and upon which fluid in the outlet branch of its service passage at a pressure exceeding that of fluid in its inlet branch can act to open the main valve at times when its pressure chamber is vented to its inlet branch through the exhaust passage for said pressure chamber;
  • fluid pressure responsive actuating means for each pilot valve operable in response to the pressure of supply fluid flowing into the inlet branch of either service passage to effect opening of the pilot valve associated with the other service passage, so that the .main valve for said "other service passage can be opened in consequence of the force exerted upon said surface thereof by return fluid in its associated outlet branch to allow fluid to flow therefrom to the associated inlet branch;
  • Circuit control means for use with a reversible 18 fluid motor, and of the type comprising a body having a pair of service passages either of which provides for flow of supply fluid from a pump to one side of the motor while the other provides for return flow of fluid from the opposite side of the motor to areservoir, further characterized by the following:
  • each service passage comprises (1) an inlet branch through which supply fluid enters the body and through which return fluid leaves the body,
  • main valves being adapted to open in response to flow of supply fluid into the inlet branches of their respective service passages to permit fluid to flow to the associated outlet branch;
  • D. means in the body defining a pressure chamber for each. main valve, said pressure chambers having communication with the outlet branches of their respective service passages;
  • El means on each main valve defining a piston which operates in its pressure chamber and upon which fluid in the chamber supplied thereto from the outlet branch of its associated service passage can act to hold the main valve engaged with its seat as long as the pressure of fluid in said outlet branch exceeds that of fluid in its associated inlet branch;
  • G. means on each main valve providing an external surface facing toward the associated bore and upon which fluid in the outlet branch of its service passage at a pressure exceeding that of fluid in its inlet branch can act to open the main valve at times when its pressure chamber is vented to its inlet branch through the exhaust passage for said pressure chamber;
  • fluid pressure responsive actuating means for each pilot valve operable in response to the pressure of supply fluid flowing into the inlet branch of either service passage to eflect opening of the pilot valve associated with the other service passage, so that the main valve for said other service passage can be opened in consequence of the force exerted upon said surface thereof by return fluid in its associated outlet branch to allow fluid to flow therefrom to the associated inlet branch;
  • pilot valves including a passageway extending through each and communicating with the inlet branch of its associated service passage through said hole in its core member and the bore of its service passage, for hydraulically balancing the pilot valves with respect to the pressure of supply fluid in the inlet branches of their respective service passages.
  • Circuit control means for use with a reversible fluid motor, and of the type comprising a body having a pair of service passages either of which provides for flow of supply fluid from a pump to one side of the motor while the other provides for return flow of fluid from the opposite side of the motor to a reservoir, further characterized by the following:
  • each service passage comprises (1) an inlet branch through which supply fluid enters the body and through which return fluid leaves the body,
  • main valves in the body, one for each service passage normally engaging the seat thereof, and which must be open to permit fluid to flow in either direction through its service passage, said main valves being adapted to open in response to flow of supply fluid into the inlet branches of their respective service passages to permit fluid to flow to the associated outlet branch;
  • D. means in the body defining a pressure chamber for each main valve, said pressure chambers having communication with the outlet branches of their respective service passages;
  • E. means on each main valve defining a piston which operates in its pressure chamber and upon which fluid in the chamber supplied thereto from the outlet branch of its associated servicepassage can act to.
  • F. means in the body defining an exhaust passage for each pressure chamber to communicate the same with the inlet branch of its associated service passage;
  • each main valve providing an external surface facing toward the associated bore and upon which fluid in the outlet branch of its service passage at a pressure exceeding that of fluid in its inlet branch can act to open the main valve at times when its pressure chamber is vented to its inlet branch through the exhaust passage for saidpressure chamber;
  • I. fluid pressure responsive actuating means for each pilot valve operable in response to the pressure of supply fluid flowing into the inlet branch of either I service passage to effect opening of the pilot valve associated with the other service passage, so that the main valve for said other service passage can be opened in consequence of the force exerted upon said surface thereof by return fluid in its associated outlet branch to allow fluid to flow therefrom to the associated inlet branch;
  • J a spring in each pressure chamber, yieldingly biasing the main valve thereof toward engagement with its seat;
  • K a separate spring for each pilot valve, to yieldingly bias the same toward its exhaust passage closing position
  • a valve assembly for use in a lockout valve, and of the type wherein a normally closed main valve controls transfer of fluid between an inlet and an outlet, said valve assembly being characterized by the following:
  • a tubularv main valve slidable axially in the chamber out of a seated position in response to force exerted thereon by fluid in the inlet whenever the pressure of inlet fluid exceeds that of fluid in the outlet, to allow fluid to flow from the inlet to the outlet, said main valve also being movable out of its seated position under force exerted thereon by pressure fluid in the outlet at a value greater than that of pressure fluid in the inlet provided said first passage is open to communicate the pressure chamber with the inlet;

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Fluid-Pressure Circuits (AREA)
US35371064 1964-03-23 1964-03-23 Circuit control valve instrumentality Expired - Lifetime US3250185A (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
GB1050181D GB1050181A (US07915450-20110329-C00059.png) 1964-03-23
US35371064 US3250185A (en) 1964-03-23 1964-03-23 Circuit control valve instrumentality
DEH53611A DE1242961B (de) 1964-03-23 1964-08-22 Sperrblock fuer die Anschlussleitungen umkehrbarer Hydraulikmotore
ES304178A ES304178A1 (es) 1964-03-23 1964-09-18 Mejoras en instrumentos de válvula de control de circuito
FR990815A FR1412072A (fr) 1964-03-23 1964-10-08 Dispositif de soupapes de commande de circuit
BE654189D BE654189A (US07915450-20110329-C00059.png) 1964-03-23 1964-10-09
NL6503624A NL6503624A (US07915450-20110329-C00059.png) 1964-03-23 1965-03-22

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US35371064 US3250185A (en) 1964-03-23 1964-03-23 Circuit control valve instrumentality

Publications (1)

Publication Number Publication Date
US3250185A true US3250185A (en) 1966-05-10

Family

ID=23390237

Family Applications (1)

Application Number Title Priority Date Filing Date
US35371064 Expired - Lifetime US3250185A (en) 1964-03-23 1964-03-23 Circuit control valve instrumentality

Country Status (6)

Country Link
US (1) US3250185A (US07915450-20110329-C00059.png)
BE (1) BE654189A (US07915450-20110329-C00059.png)
DE (1) DE1242961B (US07915450-20110329-C00059.png)
ES (1) ES304178A1 (US07915450-20110329-C00059.png)
GB (1) GB1050181A (US07915450-20110329-C00059.png)
NL (1) NL6503624A (US07915450-20110329-C00059.png)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3398649A (en) * 1966-11-16 1968-08-27 Borg Warner Hydraulic control system
US3665810A (en) * 1970-01-14 1972-05-30 Koehring Co Differential pressure holding valve
US3714868A (en) * 1970-09-23 1973-02-06 Marotta Scientific Controls Valve system for proportional flow control for fluid-operated motor
US3730220A (en) * 1970-04-24 1973-05-01 Dowty Technical Dev Ltd Selector valves
US3857404A (en) * 1973-04-30 1974-12-31 Caterpillar Tractor Co Hydraulically operated lock valve assembly
US4114516A (en) * 1976-10-15 1978-09-19 Caterpillar Tractor Co. Anti-cavitation and pressure modulating relief valve for controlling hydraulic cylinders

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3198088A (en) * 1963-08-13 1965-08-03 Caterpillar Tractor Co Fluid motor control system

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE349305C (de) * 1919-08-24 1922-02-28 Ernst Mields Absperrventil mit Fernsteuerung durch einen Dampfkolben
FR873178A (fr) * 1940-07-18 1942-07-01 Bmw Flugmotorenbau Gmbh Dispositif pour maintenir constante la pression dans des conduits ou des récipients remplis de liquides ou de gaz
GB753577A (en) * 1952-07-28 1956-07-25 Bendix Aviat Corp Improvements in or relating to combined sequence and locking to valves
US2926634A (en) * 1958-07-18 1960-03-01 Sherman Products Inc Flow control valve
US2954011A (en) * 1959-06-25 1960-09-27 Cessna Aircraft Co Pressure fluid control system and valve
US2980136A (en) * 1959-06-25 1961-04-18 Cessna Aircraft Co Hydraulic flow control system and valve with anti-cavitation feature
US3033233A (en) * 1959-07-03 1962-05-08 Cessna Aircraft Co Anti-cavitation control system and valve

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3198088A (en) * 1963-08-13 1965-08-03 Caterpillar Tractor Co Fluid motor control system

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3398649A (en) * 1966-11-16 1968-08-27 Borg Warner Hydraulic control system
US3665810A (en) * 1970-01-14 1972-05-30 Koehring Co Differential pressure holding valve
US3730220A (en) * 1970-04-24 1973-05-01 Dowty Technical Dev Ltd Selector valves
US3714868A (en) * 1970-09-23 1973-02-06 Marotta Scientific Controls Valve system for proportional flow control for fluid-operated motor
US3857404A (en) * 1973-04-30 1974-12-31 Caterpillar Tractor Co Hydraulically operated lock valve assembly
US4114516A (en) * 1976-10-15 1978-09-19 Caterpillar Tractor Co. Anti-cavitation and pressure modulating relief valve for controlling hydraulic cylinders

Also Published As

Publication number Publication date
BE654189A (US07915450-20110329-C00059.png) 1965-02-01
ES304178A1 (es) 1964-11-16
DE1242961B (de) 1967-06-22
GB1050181A (US07915450-20110329-C00059.png) 1900-01-01
NL6503624A (US07915450-20110329-C00059.png) 1965-09-24

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