US2384394A - Flow control valve - Google Patents

Description

Sep t. 4, 1945. w. A. PATTON 2,384,394

FLOW CONTROL VALVE Filed Sept. 28, 1943 2 Sheets-Sheet l m 11 T c9 7 2 l '1 I I 7 I DJRi-iQlST l V -L* l RE ERVOIR 7 FLOW CONTRGL AIJVE 112K. CONTROL SjXHOlSI' I RESERVOIR FLOW CONTROL VALVE SJKGONTROL VALVE;

,mca'. Q. INVENTOR. WILLIS BEPATTON ATTORNEYS Sept. 4, 1945. w PATTQN 2,384,394

FLOW CONTROL VALVE Filed Sept. 28, 1943 2 Sheets-Sheet 2 INVENTOR. ,7 WILLIS A. PA'ITON Patented Sept. 4, 1945 mil-MI,

ill'alllocollirol Engineering land, Ohio, a corporation of Ohio flevelantohlmaasknerts lycompany I Application September as, ms, lerlalNo. sense 12 Claims. (CL 18H!) This invention relates to a flow control valve. and more particularly to a pressure regulating and control valve for use in hydraulic fluid systems.

An object of the invention is to produce a tapered plug reducing valve of the type useful in controlling fluid pressure to andfrom single and double acting hoists. In this connection the term hoists is used in defining a single or double acting power cylinder projected and/or retracted by means of a hydraulicfiuid under pressure. such as oil. i

A further object of the in tion is to construct a fluid regulating the pressure reducing valve whereby fluid pressure may be passed therethrough in an unobstructed manner, whereby the hoist is rapidly raised, and for controlling the lowering of the piston, regardless of the weight of the load being handled, at a uniform -rate of speed. The present flow controlling valve provides a regulating arrangement which permits the lowering of any load within the capacity Of the hoist at approximately a uniform rate.

in still further object of the invention is to provide a flow controlled reducing valve having an adlustableoriflce that is maintained at a sine dependent flq'w of fluid therethrough as the hoistiisihein'gilowered whereby an automatic ioads'have controlled that is. by having 'io'perat'or .opena line leadingirom depends on the travel'Lof t'he'jiluidrele'ase sting plun er, and this proposaliis open latter undesirable feature. but requires a more complicated circuit and a multiplicity of parts. 'lhis present valve construction permits aunlform rapid or slow lowering speed regardless of the, weight of the load being lowered. provides for unrestricted raising with resulting minimum power requirements and allows for simplified construction with a minimum of parts. I

In addition to the novel features of valve combination, the invention includes a valve plunger per se, which is useful i'oriiuid control in valves other than fluid controlling or reducing valves to which the invention is primarily directed.

In the drawings. 7

Figs. 1 and 2 show diagrammatic layouts of the flow control or reducing valve inserted in single acting and double acting hoist systems:

. 3 a horizontal section partly in crossthe flow control or reducing valve on line H of Fig. 5; .4 averticalsectioutakenonlinel-l Fig.3inthedirectionofthearrows; I'll. 5 is an. temal adjusting elements of the valve; and

Fig. 8 is a side'elevation showing the ,valve plunger per se, and,particular1y the formation the hoist to areserjvoir, but'h'ere the'xl of the conical-spherical surface formed on one fluid controlling end of the valve plunger.

In Fig; l the present invention is illustrated in combination with a fluid flow system. including a double acting hoist and control valve, while in Pig. 2 the invention is shown in connection with a single acting hoist and control valve. In both .of these systems it will be observed that the fluidfrom reservoir l is drawn .therefrom by a pump 8 and passed through a suitable hydraulic control valve I and thence objection that the operator mayopenfthe port.

too'far for safety of the load lowered Other types of valves of the prior art ar'eii'n the majority of cases. limited to lowering a flxed oriflce whose size is'based .on the heaviest" load to be encountered. when lighter loads are used with the above ilxed oriflcethe lowerin time is increased. This characteristic is undesirable. If the flower fluid to raise the hoist raising will be higher than if the flow were not restricted. This too is undesirable. In some of the prior valves an auxiliary passage controlled by a check valveprovides unrestricted flow to the hoist for raising while 'itlll providing through the flow regulating valve I which is the subiectj or. the present invention. After passing the now control valve I the fluid passes alslnglejacting piston and cylinder'arrangementfpnnoist .01 :or to a double acting hoist arrangementflii for-lifting and lowering some de- {sired -oblect*or ,--apparatus. While the present invention has. ts proadfappneetton in controlling'the raisinsfinfl werliig fluid Passing to any. type ofya 'hydrauiic'hoish-the-invention has found particular aptitude inoontmllinggthe hoists used on lifting'trucks'.

In Fig. 3 the I in detail. Herexthe jflow controlling valve memher comprises a casing. ilhaving inletgport I! connected by suitable fluidpressure piping-to =-a single or double actint'fioontrol valve. I. n Th Ior restricted lowering. This eliminates the opp site-si e ofthe fl a r -wa I! end plan view showing the ex-" meme verve intranet shown the maximum diameter of the skirt of the conical-spherical plug ii that forms apart or the valve plunger ll. The valve plunger is illustrated in detail in asses Fig. 6 and comprises an elongated body having a progressively increasing spherical-conical plug section II previously mentioned. The conicalsphericsl section ll of the plug is joined to an enlarged diameter hollow cylindrical portion 31 by a reduced diameter central extension I. It will be observed that'the outside diameter 4'. of the enlarged hollow cylindrical section 31 is greater-than the diameter of the rear edge of the. conical-spherical portion SI of the plunger.

From enlarged view I it will be observed that v the conical-spherical plug section It of the sliding valve is gradually tapered from its forward curved face portion 8! to its rearward skirt portion II. The extreme rear-diameter ofthe conical-spherical plug is'very'slightly smaller than the diameter of'th hardened oriflce bushing II.

The enlarged cylindrical'portion 81 is'mounted in and adapted to slide within a bore li formed in the solid valve body =25. The valve body 28 is also provided with a second reduced diameter bore or passage lying in spaced parallel relation tothe plunger'bore H and joining a lateral extension of the main fluid passage !i adjacent the-port I'I. Reduced diameter passage 43 is fltted with a hardened bushing". at

the. end of the passage terminating in a trans? verse fluid passage" which extends between and Joins the bores ll and II. The eflectiv'e die ameter of passage 43 is controlled by th position 'of a tapered valve pin ll positioned in bushing 'fl-andhaving a shank 49 which is screw threadplunger. .Adiusting screw I] is provided with a lock nut arrangement on its exterior end.

in the operation of either the single or double actingsystems shown in Figs. 1 and 2, when the fluid control valves I are operated to raise the hoists, hydraulic fluid from the pump is introduced through the port II and passes freely through the valve casing and outwardly to the hoist through port ll. Fig. 3 shows the position of the parts of the flow regulating valve whenthe hoist is being raised. Fluid irom the pump 8 passes inwardly through port i'l into enlarged chamber 2i, through passage 28 and outwardly through lateral passage 21 and port II. I! it so happens that the valve plunger II is not in the iully opened position, as shown in Fig. 3, the incoming fluid pressure passing through passage 43 around tapered valve pin is into lateral passageway 41 and thence into the rear cylindrical bore or hollow formed within enlarged diameter portion 11 of the valve forces the valve plunger 30 to the right until end I! abuts the screw '3 to maintain fluid passage 23 fully open.

When the control valve I is positioned to lower 7 the hoist the'flow of oil through the valve is reversed. Oil from the hoist enters the valve at port ll, flows through passages 21, 2! and II left 'of'plun'ger 30 by pressure causes a correed through the end of the valve casing and terminating exteriorly of the casing in an adjusting means and lock nut arrangement as is conventional in the art.

The outer end of bore Ii is enlarged in diameter throughout the portion extending between the transverse fluid passage 41 and the exterior of the valve casing for the reception of a threaded plug ll having an adjusting .screw ll extending therethrough and terminating exteriorly in an adjusting head and lock nut arrangement. The inner end of the adjusting screw II bears against the enlarged head II of a guide rod I'I positioned within a coil spring 59. This coil spring is positioned within the hollow of portion 31 of the valve plunger and is held between the inner end of said hollow and the under side of the enlarged head II of the guide rod 1. It is obvious that i by regulating the position of adjusting screw I! that the tension Of the spring may be readily adiustedto vary the pressure exerted on the valve plug. Under the action of, this spring the entire valve plunger is moved to the right until the end 8| contacts the adjusting stop screw 03 threaded in pl g II which in turn is threaded into theoasing directly behind the end of the passages 2i and 23.

and leaves the valve at port ll, returning to the control valve 8 and then back to the reservoir. The oil entering port II is under pressure due to the load on the hoist and acts to move plunger 30 to the left because of the diflerential in area between portions I1. and II; This movement is opposed by spring I! which has been designed to take care of any reaction caused by the load on the hoist acting upon the before+mentloned diflerential in area of the ends of plunger I up to the full capacityof the hoist. Movement of plunger 30 to the left causes the conicalspherical plug 3| to enter passage 28 thereby causing a restriction in the flow oriflce at the right end of passag 23. Since the volume of liquid flowing through an orifice is aflected by causing the flow, the longitudinal contour of a plug ii is such that a given movement to the sponding restriction of oriflce size so that the volume of flow through the oriflce is a constant regardless of the pressure causing the flow. As a result of the uniq-ueconstruction or plunger II as just described it is possible to have hoists O or ii lower at a constant rate of speed regardless of whether they are lightly or heavily load- The construction and operation of this valve mechanism as already noted assures the flow oriflee being 'wide open during the, raising of the hoist and thus no appreciable restriction to flow is encountered during this phase of operation.

The purpose of adjusting screw 63 is to control the initial drop of the hoists by allowing for adjustment of the initial opening or orifice between passages 23 and 2|. It is evident that when the control valve is positioned for lowering .an initial momentary drop will b experienced by the hoists until plunger 10 reaches its balaneedv position at which time regulated lowering will be accomplished. Under ordinary circumstances plunger "would be adjusted to the left by means of screw 0, until a build up in pressure, when the valve is in the raise position, indicates theta restriction is being created between The amount of this opening would then determine the amount of initial drop in the lowering position. Should this drop turn is governed by function properly.

the left thus creating a further restriction. It-

is evident that when the initial drop must be less than normal a build up in pressure will resuit in the raise position. While this is not desirable agmentioned previously it may be the lesser of twojevils depending upon conditions. Use of adjustment screw 03 also-allows the present valve to operate successfully over a fairly large range of volume.

The headed rod 51 acts as a guide for spring 59 and also as a stop limiting the movement of plunger 30 to theleft. This latter function while not absolutely necessary is an added precaution against overtravel of plunger 30 which might result in Jerky or jumpy lowering of the hoists by completing shutting off flow through the orifice.

The rate of speed at which the hoists lower is governed by the setting of spring 58 which in the position of adjusting screw 53. Turning screw 53 inwardly increases the tension on spring 59 which decreases the amount of travel of plunger 30 for any given pressure in passage 21 thereby increasing the lowering speed of the hoists by allowinga larger orifice opening. Turning screw 53 outwardly releases the tension on spring 58, allows plunger 30 to travel farther to the left for a given pressure in passage 21 thus causing a greater restriction in orific size which in turn results in slower lowering of the hois Since passages 41 and 43 are always full hydraulic fluid it is evident that any'movement to the left of plunger will cause a displacement of said fluid into passage 2|. By governing the rate of flow of this fluid by means of a tapered valve pin 48 positioned inside of bushing the speed at which plunger 30 reacts to the pressure inpassage 21 is controlled. Thus any jumpy or jerky action which might result from sudden impulses or surges is cushioned with the result that even, steady lowering of the hoists is obtained. Because the hydraulic fluid in passage 41 has a deflnite function when the hoists are being raised and also when they are being lowered it is essential thatpin I! never entirely close oil passage 43 if the valve is to I claim:

1. In a fluid pressure flow control valve adapted to remain fully open to flow in one direction and to control the rate of flow in the other, a housing provided with two fluid chambers joined by a restricted passage, a sliding valve plug controlling the flow of fluid through said passage, an adjustable spring loading means engaging and normally holding said valve plug in open position and a branch passageway leading from one of said chambers to the end of the valve plug engaged by said adjustable spring means to apply pressure thereto. I

2. In a fluid pressure flow control valve adapted to remain fully open to flow in onedirection and to control the rate of flow in the other, a housing provided with two fluid chambers, a sliding valve plug separating said chambers, a cavity in one end of said valve plug, an adjustable compression spring positioned therein normally holding said valve plug in open position, and a branch passageway leading from one of the said chambers to the said valve cavity.

3. In a fluid pressure flow control valve, a housing provided with ported chambers, a partition separating said chambers, said partition having an oriflce joining said chambers, a sliding valve member having a spring behind the enlarged diameter cylindrical valve portion and normally holding said valve plug in open positionwhereby fluid may freely flow therethroughin one direction, and a restricted fluid passage leading from one of said chambers to the rear of said enlarged diameter cylindrical valve portion;

4. A fluid control valve as defined in claim 3 wherein the said enlarged valve member portion comprises a hollow cylinder surrounding the said spring, the inner solid end of said cylinder being reduced in diameter to form said connecting portion for carrying the spaced conical spherical valve plug of smaller diameter than the cylindrical portion, the maximum diameter of the remote end of said tapered conical-spherical valve plug closely approximating the diameter of said orifice.

5.- An adjustable fluid pressure reducing valve comprising a housing, means dividing the housing into two compartments, the dividing means having an oriflce joining said compartments, a reciprocating valve plug having enlarged diam- 80 eter end portions and a reduced diameter central portion, trolling the flow of fluid through said oriflce, said valve plug being normally held in open position by a spring engaging one end thereof, means 85 external of the valve housing for adjusting the 0 fluid flow in said fluid passage leading from one Q tension of said spring and a restricted fluid passage leading from one of said compartments to the end of said plug engaged by said spring.

6. A valve as deflned in claim 5 wherein the of the said compartments to the end of the valve plug is controlled by a tapered valve adjustable from without the valve housing.

'7. A valve as defined in claim 5 wherein one of the inner adjacent faces of the enlarged end sections of the reciprocating valve plug is of greater diameter and frontal area than the other v of said end sections.

8. A'valve as deflned in claim 5 wherein the inner face of the enlarged e d portion having the spring mounted thereagainst is flat and of greater diameter than the inner face of the adjacent enlarged end portion, said latter having a gradually tapered conical spherical face.

9. A valve as deflned in claim 5 wherein the valve plug bore and the fluid passage leading from one of the compartments are in spaced parallel relation.

10. A flow regulating valve comprising a valve body provided with two compartments Joined by enlarged and portions,

an orifice, a reciprocating valve plunger regulating the flow of fluid through said oriflce, said valve plunger consisting of an elongated member having a reduced diameter portion joined to of said end portions adjacent the reduced diameter portion being greater than the other, spring means. normallyholding said valve plunger in fully open position whereby fluid may freely pass in one direction around the valve. end portion of lesser frontal area, the pressure of fluid flowing in the opposite direction forcing the valve end portion of greater diameter to move said valve plunger against the tension of the said spring means and tend to position the end portion of slightly tapered conicalspherical plug controlling the area of said orifice,

. a connecting portion passing through the oriflce and an'enlarged diameter cylindrical portion, .a}

one of said enlarged end portions con-- the frontal area of one hm tho 12.A-flow fluid-now thuethrough when! the fluid now 10 whu-emthe h-oonmt'mmoflhcmnclmlngtho when the add vdveuln

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