US2642088A - Flow control valve - Google Patents

Description

June 16, 1953 H. KlRKi-IAM 2,642,088

FLOW CONTROL VALVE Original F 'iled April 17, 1944 3 Sheets-Sheet 1 Nil 10 Aillll ,7" i 35; v v

June 16, 1953 KIRKHAM 2,642,088

FLOW CONTROL VALVE I Original .Filed April 1'7, 1944 3 Sheets-Sheet 2 i gwuwwkw HJ SLL KIRKHQZ June 16, 1953 H. KIRKHAM FLOW CONTROL VALVE 3 Sheets- Sheet 5 Original Filed April 1'7, 1944 v Patented June 16, 1953 FLQW CONTROL, VALVE Hall 'Kirkham,

Cleveland, Ohio, assignor, by

mesne assignments, to The New York Air Brake Company, New York, N. Y., a corporation of New Jersey Original application April 17, 19,44, Serial No. 662,839. Divided: and this application ()ictober 13, 1948, Serial No. 54,279

This invention relates to control valves for hydraulic devices, and more particularly to such valves for handling the flow of liquid to and from the operating plungers of double acting rams associated with such devices asbulldozers, bull graders, scrapers, lift of a like nature.

More particularly the invention is concerned with a control valve to be introduced between a doubleacting hoist or ram and a source of high pressure liquid for controlling the operation of the hoist or ram, permitting 'it to be raised or lowered; at anydesired speed and independent of the load thereon.

' An important object of the invention includes the provision of a control valve for hydraulic devices having associated therewith flow control valve means arranged to' control the return of liquidfrom the low pressure side of the ram or hoist to thereservoir ata speed, dependent on the rate of supply offhigh pressure liquid, to the other, side of thehoist and wholly. independent of; load n the hoist which may tend to advance itfmore rapidly than the supply of high pressurefluid'.

One of theimportant features of the inventionlcomprises. the arrangement ofjthe flow control valve wherein, its operation is transferred from one side. of the hoist to, the other automatically by manual operation. of the main, control valve plunger.

Another mportant, feature of; the invention comprises the unique. arrangement. oi the, flow control. valve, whereby the return. of. low pres.-

sure. iiquidiromjone side, ofthe hoistv or. ram

is. definitely controlled, by the. pressure on the operating liquid on the other sidoQf the. ram,, Still another important. feature of the inventionresides in the, construction and arrangement of, the fiow control valve whereby it is given a dashpotaction to prevent fluttering andsurging. For a more complete understanding of the inventionireference should be had to thejaccompanyine' drawings and iollowing sp ificati n. wherein is discloseda single exemplary embodiment. of. the invention... with the understanding thatsu h. n s. and, modifications. may be. made therein as fall; within the. scope. of; the. ap pendedclaims without departing fromotheispirit of, the invention.

Insaid drawings;

Figilis a sideelevation of, the assembled valve;

Fig, 2' is avertibal, central section through the same. on the. axis. ofthe. plungeri, Fig. 3 is a horizontal section through the cap trucks and machines.

' threaded passages 2 or cover element taken on broken line 3-3 of Fig. 2 and illustrating both the system relief valve and the flow control valve;

Fig. 4 is a horizontal semi-section taken on line 4-4 of Fig. 2, note being made that the valve housing is symmetrical about the central line;

Fig. 5 is a horizontal section on line 5-5 of the base portion of the valve illustrating the-high pressure inlet and check valve; and

Fig. 6 is a fragmentary horizontal section on line 6-6 of Fig. 1.

In the operation of various types of equipment by means of hydraulic hoists or rams of the double acting variety, difficulty is sometimes experienced by the load taking control of 'the'rate ofmovement thereof and causing the ram piston to" advance more rapidly than high pressure fluid is supplied: thereto, it being remembered that the fluidcan either be throttled to limit the desired rateof movement or is obtained from a pump of limited capacity. In the operation of earth moving equipment such as bulldozers, bull graders, scrapers and the like. extremely smooth lowering of the blade is desired to obtain the fine results of which these machines are capable. Such lowering requires positive control of the flowof low pressure liquid from the side of the piston of the ram opposite to that to,

which the high pressure liquid is delivered, so that the condition noted' above cannot exist; The present invention contemplates a unique arrangement of the manually manipulatable controlvalve andthe flow control valve.

Referring now to the drawings, and particu larly to Figs. 1, 2' and 5, it will be noted that the valve housing comprises three main parts, including lower or base section B, which is conveniently equipped with extending flanges l0, perforated as shown at H in Fig. 5 for mounting the valve housing on any convenient support. As also seen in both Figs. 1 and 5, the lower section provides threaded inlet passages l2, I2, so that liquid from the pump may be delivered to either of these as is most convenient, a plugsuch as shown in the passage 12 in Fig.5 closing the unused one. I 1 The'central or control valve section C contains ports and passages for cooperation with the cap and bottom sections and with the valve plunger P. It also contains, as" seen in Fig 4, Hi and I5, respectively, open through the side for conducting liquid to and from the two ends of the hoist or'ram. Since the section shown in Fig. 4 1s symmetrical about the center line these passages I4 and I5 are duplicated on the other side, for the reasons pointed out in connection with the bottom section, and the ones not desired to be used can be appropriately plugged.

The top or cap section D includes through its upper surface the low pressure fluid delivery passage I8 from which a pipe connects to a suitable reservoir or tank for the reserve liquid. This section also houses, as seen in Fig. 3, the system relief valve 29 and the flow control valve 2| appropriately connected by passages to the center section.

As shown in Fig. 2, the several sections of the valve housing meet along plane surfaces 24 and 25, each intersected by the desired passages and ports. Leakage is prevented by means of a gasket surrounding all passages or ports or by means of composition rings, set in appropriate grooves such as are shown at 25 in Fig. 2. It will be understood that each of the grooves or channels 26 is a continuous closed passage around its corresponding port. The rings may be of the swellant variety, which expand upon contact with the liquid to thereby effect a seal, the non-swellant variety, which seal by deformation or they may be of a combination variety, which combines the virtues of the other two. The sealing ring means of preventing leakage is considered superior to the gasket means. The several sections of the valve housing are appropriately secured together by through bolts, as shown at 21 in Fig. 1.

In Fig. 5, bottom section B is shown as provided with a high pressure liquid chamber 28, to

which liquid is delivered from the constantly op erating pump of the positive displacement type through one of the passages I2, I2. A cored passage 29 leads from the chamber 28 to the check valve 30, comprisinga hollow plunger 3| seating on the lip 32 of bore 33 extending from passage 29. This plunger is seated by means of the housed spring 34 abutting and positioned by screw cap 35. Oil under pressure is able to lift the plunger and to flow into passage 36 parallel to passage 29 and leading to vertical ducts 31 and 38, also seen in Fig. 2, This latter figure also shows a vertical duct 39 leading from chamber 28. Each of the ducts 31, 38 and 39, extends through the top wall of the bottom section and connects to a corresponding duct 31, 38' and 39', respectively, in the center section.

This center section is longitudinally bored as at 40 throughout its length to provide a close working lit for the manually operable cylindrical plunger P, shown in this figure in its center or neutral position. The bore 40 is variously intersected by channels, passages and ports under the control of the valve plunger, which is equipped with sections of reduced diameter, or grooves, as shown, permitting fluid flow, when they are appropriately positioned between selected ones of the passages, channels and ports, as will later appear. The end portions of the plunger extend out through the Walls Of the housing and are maintained fiuid tight by appropriate seals 42 held in position by cover plates. These seals are vented by passages 43 which lead to the low pressure discharge passage I8, as shown, to insure that the seals will never be required to prevent leakage of high pressure fluid which may seep by the controlling diameters of the valve plunger.

Passage 39 in the center section is continued in an offset passage 45 which intersects the plunger bore. Closely adjacent it is the passage 46 connected to low pressure exhaust chamber I8 by an extension 46'. valve plunger insures flow from 28 to 39 to 39 to 45 to 46 to 46' to I8 and back to the tank. This arrangement insures that the pump works against substantially zero pressure when the valve plunger is in the neutral position and no work is being done by the system. When the plunger is moved toward the left, flow is stopped between 45 and 46 by the end section 50 of the plunger and when it is moved to the right, by the narrow land 5I.

When the plunger is in the neutral position shown, relief of the high pressure liquid as just described permits the check valve 30 to remain closed, but if the plunger is moved in either di rection to close off the flow between 45 and 46 a simultaneous connecting of one or the other of the ram ports I4 and I5 with the high pressure liquid is effected as follows: These ram ports have connected passage of corresponding numbers primed which intersect the plunger bore as seen at I4 and I5 in Fig. 2 and which are normally closed by the lands 53 and 54 of the plunger when in neutral position. If this plunger is moved toward the left, passage 38 is connected by groove 55 with passage I4, the check valve is opened and high pressure fluid flows to one side of the ram. At the same time land 54 uncovers passage I5 and groove 56 in the plunger connects I5 to passage 60 which leads to passage 6I in the upper section of the valve. This passage extends up and around the hollow section 62 of the flow control valve, and when this valve is lifted liquid flows from 6| into cross passage 54 which connects with 46' and the low pressure chamber I8, as clearly seen in Fig. 3. The operation just described results in movement Of the ram in one direction under the action of high pressure liquid and causes the return of liquid from the opposite side of its piston back to the tank under the control of valve 2 I.

Movement of the plunger P to the right reverses the operation of the ram as follows: High pressure liquid flows through the check valve 30 into passages 31 and 31, through groove 66 in the plunger to the passage I5 and direct to the other side of the ram. Low pressure fluid from the opposite face of the ram piston enters the valve at I4, flows into I4, and by means of groove 56 in the plunger enters 60 and BI and eventually finds its way in the cross passage 64 and back to low pressure I8 as already described. The check valve provides a safety means to hold the ram in whatever position it may be and in spite of whatever load may be on it in the event of failure of the pump or the pipe line between the pump and the valve.

It will be noted that the high pressure chamber 38 is connected to passage 38 which intersects the plunger bore and this passage continues, having eventual connection to chamber 58 in the cover section of the valve, which has a vertical extension 68', seen in Figs. 2 and 3. This is connected to bore I0 of the system relief valve. This bore is provided with a pressed-in seat II against which the plunger 20 is held by helical spring 72 under the control of adjustable follower I3 positioned by means of screw threaded rod 14 in the cap I5; If for any reason pump pressure becomes too great, such as by failure of the ram to move, clogging of pipes or hoses, etc., unseating of the relief valve 2!! permits discharge of high pressure liquid from 68 into 64 and hence to the tank. It will be noted that this relief is The groove 48 in the ing the same.

available"at all'times when'the plungeris notin 38,38 is connected 7 the neutral position since to 28 whenever the check valve is lifted.

The flow control valve2'! which determines the :rate at which low pressure fluid returns from the idling side of the ram plunger-tothereservoir by way of passages 60 and 6! is shownin Fig. 3. The valve plunger operates in .a bore 11 extending through the cap section of the housing transverse to cross passage 34 and-intersect- The 'valveis of the spool type, having the solid end 18,the intermediate neck section and the upper section '52 hollowed out to receive the light helical .against the closure cap 8!). and tendingto press the valve with its end 18 against the adjustable stop 8| threaded into the cap 82 in the opposite end of the bore. .This capiis bored with a larger diameter than l! to permit liquid to flow from chamber 34 to the under face of the portion 13 to move the valve against the spring. As the valve plunger 2! is moved against the spring -more and more flow is permitted from 3'5! into '64. The cylindrical portion 62' of the plunger, which normally closes the passage ti, :down to 85 but is equipped with tapered slots :86 which are so arranged that complete closure between 6! and M can never be efiected. The tapering arrangement :of'these grooves insures increased flow as the valve movesagainst the spring.

The chamber receiving spring is is extended in a small bore .83 connected by a drilled hole 85 :tothe'outside of the narrow portionof the valve 'plunger'to insure discharge :of any oil which may seep intothe spring chamber and also to impart "a dash pot action, to prevent fluttering or rapid fluctuations in the movementof the valve plunger in a manner Well recognized.

' The passage 84 surrounding the head. E8 of the 1 valve plunger 2! is connected by extension .95

and passage with (38', which, it will be remembered, is always open by devious passages to the high pressure chamber 28. the system using the capacity, it will be appreciated that if because of a load on the ram tending to move it in the direction it is already being urged by fluid deliv- I ered to one side of its piston, there is a tendency 'for'the piston to move more rapidly thanifluid'is :provided behind it, then the pressure on the liquid-being delivered by the pump will immediately fall. Advantage is taken of @thisti-n the operation of the flow control valve, for when pump-pressure is reduced in passage 86 the spring flow control-valve plunger against its stop 8! and fluid flow from the low pressure side of thefram piston is throttled between 6! and 54, stopping the unwarranted increase in speed of the ram from the loadthereon. As soon as the pump catches up, pressure increases, fluid is delivered into 84 and the valve isopened to the desired degree to permit the ram to operate in its normal manner. To insure against rapid changes in pressure in M, the connection'between extension 90 and passage ti, best shown in Fig. 6, is by wayof a restricted bore 93 controlled by an adjustable needle valve 9 as shown.

The needle valve 94 is in the nature of a metering pin which makes it possible to controlaccurately the rate of flow of fluid from the low pressure side of a double acting ram to prevent the piston from getting ahead of the fluid on the other side. Such controlled action makes it possible to have any desired lowering speeds on such spring 59 abutting extends I Since the pumpfor present valve is of a limited i 9 closes the zaeraoss instance, of a bulldozer -caused by the work. two ends of the ram cylinderare different because position of said plunger which'rdoes not allow for i machines. Theposition of the set screw 8| governs the amount of initial opening between pasalso governs the amount'of sages 6i and E i and travel of the flow control valve necessary. to bring the main recess in'this valve into play to fully open the passage from-ii! to 64.

In addition to the neutral and two power positions of the plunger'P, it maybe pulled out an extreme distance to the right to provide whatis known as, a float position. This movement carries land 5! into passage as so that high pressure fluid flows freely from into is and the pump is unloaded. Groove now connects rampart IE to passage til, which is also connected to ram port !4' by groove 53. This provides for communication between the liquid on the two sides of the piston of the ram, permitting the blade, for to assume any position The displacement of the of the presence of the piston rod at one end,-.so that when moving in one direction an excess of oil must be discharged and when moving in the other direction oil must be added to the circuit. This is simply effected in the valve shown, since thepassage til to which both ends of the ram cylinder are now connected is always uninterrupted in communication with low pressure cross passage Gil because the valve '2! is never permitted to fullyclose'communication between 6'! and 64 because of the grooves 86. In this way oil from the reservoir can be delivered to the ram circuit or can be discharged from the latter to the reservoir to provide forthe floating action. If for any reason the float position of the valve is not required, then the construction of valve 2ijis modified by the omission of the groovesfit, which allow constant communication between ii! and 64 and thus prevent destructive load imposed pressures occurring inpassages'tli and t I These pressures can only occur when plunger P is in the floatposition since this is the only operating pump induced high pressure fluid acting on end .1801 plunger 2-! to thus move it against spring -19 to bring passages 5! and 64 into communication via the central groove of plunger 2L. Itis thus evident that elimination of the float condition automatically removes any need for grooves .86 and thus allow for simplification of plunger. 2

Because of the peculiar arrangement of .the passages and ports in the intermediate section of the valve housing, more than one suchsection can be arranged between the bottom and cover sections, permitting controloiseveral double actingrams. .In' order to insure proper operation with multiple pressure sections it will be noted that passage 31 as well as passage, 38 extends vertically entirely section and is closed 01? at 96 by a blank section of the cap or cover. The passage 66 is also carried through to be closed off by the bottom section, as shown at These extensions provide through passages in the eventof multiple use of plunger sections. tions are in use the ones above and/or below the one actually in operation, act merely as elongations of the passages or ducts between the various oil channels in adjoining sections.

This application is a division of my copending application Serial No. 662,839, filed April 17, 1944, and issued July 22, 1952, as Patent 2,604,327, for Control Valve With Flow Control.

I claim:

1. A flow control valve of the type described,

through the central housing Where several of these seccomprising a housing having a bore; means closing the ends of the bore; a duct intersecting said bore; a plunger having spaced lands and an intermediate groove movablein said bore between limits with said groove and duct in communication; a passage intersecting said bore and substantially closed by one of said lands when the plunger is at one of its limits; a spring to so position the valve plunger; means to introduce high pressure liquid into said bore at the end opposite said last mentioned land to move the plunger against said spring and further open said passage to said groove; and passage means in said plunger from the bore beyond the last mentioned land to said groove to afford a dashpot action therefor.

2. A flow control Valve for limiting the rate of movement of a double acting hoist to that determined by the delivery capacity of the liquid pump therefor, comprising a housing having a bore closed at its ends; a duct intersecting said bore; a plunger freely reciprocable in said bore, having end lands with a, working fit therein and a groove arranged to register at all times with said duct; a chamber at one end of said bore; a delivery bore for operating liquid, opening into said chamber; a spring biasing said plunger toward said chamber; an inlet passage for fluid intersecting said bore and substantially closed by the land at the opposite end of the bore from the said chamber when the plunger is at one of its limits of reciprocation, movement of the plunger against the spring providing progressively increasing communication between the passage and duct; means to limit the movement of the plunger toward said chamber always to maintain limited communication between the passage and duct; means to adjust the rate of flow in said delivery bore; and a restricted passage in said plunger from the end opposite said chamber to the surface of said groove to provide dash-pot action.

3. A flow control valve for limiting the rate of movement of a double acting hoist to that determined by the delivery capacity of the liquid pump therefor, comprising a housing having a bore closed at its ends; a duct intersecting said bore; a plunger freely reciprocable in said bore, having end lands with a working fit therein and a groove arranged to register at all times with said duct; a chamber at one end of said bore; a delivery bore for operating liquid, opening into said chamber; a spring biasing said plunger toward said chamber; an inlet passage for fluid intersecting said bore and substantially closed by the land at the opposite end of the bore from the said chamber when the plunger is at one ofits limits of reciprocation, movement of the plunger against said spring providing progressively-increasing communication between the passage and duct; means to limit the movement of the plunger toward said chamber always to maintain limited-communication between the passage and duct; and adjustable means in said delivery bore to meter liquid moving in either direction therein.

4. A flow control valve for limiting the rate of movement of a double acting hoist to that determined by the delivery capacity of the liquid pump therefor, comprising a housing having a bore closed at its ends; a duct intersecting said bore; a plunger freely reciprocable in said bore, having end lands with a working fit therein and a groove arranged to register at all times with said duct; a chamber at one end of said bore; a delivery bore for operating liquid, opening into said chamber; a spring biasing said plunger'tovvard said chamber; an inlet passage for fluid intersecting said bore and substantially closed by the land at the opposite end of the bore from the said chamber when the plunger is at one of its limits of reciprocation, movement of the plunger against the spring providing progressively increasing communication between the passage and duct; means to limit the movement of the plunger toward said chamber always to maintain limited communication between the passage and duct; a closed chamber at the opposite end of said bore; and a restricted passage connecting said last mentioned chamber to said duct.

5. The valve as claimed in claim 4 in which said limiting means for the plunger is adjustable and in which the land opposite the first mentioned chamber has a longitudinal slot of decreasing depth extending from the groove toward and intersecting the passage at all times.

HALL KIRKHAM.

References Cited in the file of, this patent UNITED STATES PATENTS Number Name Date 1,034,662 Turner Aug. 6, 1912 1,217,183 Jackson Feb. 27, 1917 1,853,863 Hornbruch Apr. 12, 1932 1,871,043 Chalmers Aug. 9, 1932 2,271,031 Parker Jan. 27, 1942 2,347,238 Bennett Apr. 25, 1944 2,420,394 Gilman May 13, 1947 2,453,812 Phelan Nov. 16, 1948 2,474,122 Schneck June 21, 1949 2,489,435 Robinson Nov. 29, 1949 2,494,714 Lyman Jan. 17, 1950

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