US2607321A - Hydraulic control mechanism - Google Patents

Description

Aug- 19 1952 A. L.. LADO HYDRAULIC CONTROL MECHANISM 2 SHEETS-SHEET 1 Filed Aug. 19, 1946 m .s a N w f v2.

H @EIQW JNVENTOR. L- L @do M3 ArroRNErs.

Imms. mm. n. B

AU 19 19452 A. LADO 2,607,321

- HYDRAULIC CONTROL MECHANISM Filed Aug. 19, 194e 2 SHEETS- SHEET 2 KET: 2o 25 y/////////////17/ Patented Aug. 19, 1952 `UNITED SI'l=\l'[ l5`;S PATENT OFFICE Y n, 'I v l l l2,607,321 i Y HYDRAULIC `CONTROL MECHANISM` Anthony L. Lado, Rome, N. Y., assigner, by mesne.

assignments, to Rome Grader. Corporation, RomeN. Y., a corporation of New Yorlr n Application August 19, 1946, Serial No.762l1g572lf i 2 Claims. (Cl. 121-541..)

. l Y This invention relates to a control mechanism, particularly a mechanism used tocontrol 4an object which is moved by fluid under,v pressure. An object of the invention is to provide an improved control mechanism which fwill. easily and accurately controla movable article. g

Another object offthe inventionis to p rovide aniimproved vcontrol vmechanism which vmay be set to move an-article any desired distanceand will permit the motion of the article to be accomplished subsequentlyjhe article being accurately stopped'when, its' motion vhas brought it to a desired point. i l y Another object of the invention is to provide an improved control mechanism which may be used to` move an varticle selectively in either of two or more directions. f v Y y 4Another object ofthe invention is toyprovide an improved control mechanism-which may move an article directly from one position to any other desired positionfwithin its range of possible motion.A v 'v- 'r Another object of the invention is to provide an improved controlmechanism which may reverse the motion of an article at any point in its travel. v Y -f @1 Another object of the inventionA is to provide an improved control mechanism which will be simple in construction. 1

Another object of the invention is to provide an improvedvv control mechanism which will be easily assembled and disassembled. n 4

Another objectof ythe invention-is to provide an improved control mechanism which will balance fluid pressures within the control. l

Other objectswill hereinafter appear. p The invention will be better understood from the description of one practical' embodiment thereof, illustratedin the accompanying drawings, in whichzfi Figure l a somewhat diagrammatic longitudinal sectional viewofa control mechanism embodying my invention,y this `being designed primarily for use as apart of the steering gear of a vehicle; v n l Figure 2 is a fragmentary horizontal plan section, taken on the line II-II of Figure 1, and showing a neutral position of the exhaust ports; Figure 3 is a fragmentary transverse sectional view taken on the line III-III of Figure l; and Figures 4 to 8 are longitudinal sectional views, similar to the right hand part of Figure l but showing various positions which may be assumed by thev ports in the operation of the control.

The apparatus shown in the drawings is inf 2` 1 tended for moving an article in either two opposed directions by varying amounts, as may be determined by the operator, as for instance the moving of the steering wheel or wheels of a land vehicle, or the rudder of air or water craft, or the like. Y f

Thepartv` actuated needvnot be'V a control element; but canbe any movable article which it may be desired tofmov'into any one of a vplurality positions, but the types of control elements above mentioned furnish a convenient example, and so are chosen for the purposes of illustration and explanation, it being understood'that the invention is not, however, limited to .such elements. f4

To show a very simplified control, the operator has been provided, in the device illustrated,'with a manually movable crankl xed to an .arm 2 whichis fastened to a threaded shaft 3, vas -by the clamping bolt'lli. v

The shaft is shown as supported in a bearing 5, carried by a Stationary bracket 6, the shaft being held from axial movement by a ange or collar 'I engaging one side of the bearing and the hub portion of the arm 2 engaging the other side thereof.

The threaded portion 8 of the shaft 3 engages the internal thread of nut 9, pivotly carried at the end of a lever I0, lthe center of which is shown as pivoted at II on an extending lug I2 of the control apparatus. The upper end of the lever I0 is pivoted to a link I3 which in turn is pivoted to .a control valve sleeve I4.

Sleeve I4 is shownas cylindrical, having an open inner end and a closed outer one to which the link I3 is pivoted, and may reciprocate within a cylinder I5.

The cylinderv I5 has formed in its inner'surface four recesses, which for clarity of illustration have been shown above and below the sleeve and to one side thereof. The recess I6 below the sleeve is connected by the ttings and pipe I1 to a source of fluid under pressure, such as a pump l? delivering oil, other liquid, air, gas or any other fluid pressure transmitting medium to the apparatus.

In the example illustrated, it is assumed that the fluid used will be of liquid nature rather than a gaseous one, and the parts are therefore smaller an-d heavier in their proportions because of the high pressures which may be practicably attained with such liquid or hydraulic media.

A-bove the sleeve are shown two spaced recesses I8 and I9 in axial alignment with each other, the former of which is-connected by fittings and a pipe or tube 20 to the right hand end of a cylinder Within the sleeve valve I4 is a valve piston 25 sired to move the article connected to ring 41 which is provided with two passages, shown as l peripheral grooves 26 and 21,1-'and thisgpiston is connected xedly to a piston rod 28 which` extends through packing '29., Lheldin =a vgland in the end of cylinder I5, "into thencylinderm.

Within this last mentioned cylinder the piston rod is provided With a piston Sll carrying vpacking 3l which may be caused to travel Within a .cylinder 2| by diierentialpressure of the 'fluid 'selectively supplied through pipes 20 and 22 to yThe Ypiston rod '28 'also continues through -a .cylinder'head z32 'at-f thev4 end d'of cylinder 2'I remote from the valvemechan'ism into Lasecon'dcylinder `33 Which is 'closed on its further end-by va head- 3 4.

,The cylinder head formed b y the end of valve vcylinder I5, V,the head 32, andthe head 'i3-'4 are clamped together by through bolts and `nuts 35'.

Within 'cylinder 33 varidfix-edto the piston -rod 28isa piston 36, provided 'jvvith packing 31, land from Vlheads' 32 and 34 acommunicationwith the 'interior' of cylinderg33 is' established b y littings Yit is desired .to move.

Returning to describe .the `control 'valve mechanism in .more fparticularity, the sleeve 'Iltis provided with a number. of ports 'therethrough aslfollows:

Throughthe'bottom of vthe sleeve I4; thatis, through the portion in 'alignment `withrecess I6, areports 348 and 4.9, "these .being :so YspacedI that the distance 'between them'is 'atleast equal `to .the distance between the 'extreme Vedges 'of .grooves-,26..and'21,' thus bothgports may be closed when piston 25isinithe neutralposition shovvn in Figure '1.

.Diametrically .oppositeport v.48, and arranged kto communicate Withggroove ;26 Vand recess I8 is .a portl, -andoppositeport 49 .and 'arranged Vto communicatewith groove/21 and recess I9` is :a similar por't'l.

Between `these ports, .and Yalso 'in alignment withrecesses '|28 .and `[9,= are two .ports 52. and '53, these being spaced. so that the vover-all Adistance across them'is no greater than the 'length of -thatpart of the,piston between grooves26 and 21, .so 'that'bothjports may be closed'bythe central part 'of the pistonwhen the ports are ina 'neutral positionfas in Figure v'1.

In longitudinal Ialignment Ywith ports 52 and 53, but oiset "to the 'side 'of 'the lsleeve 4to `communicate With'recess i23,"are, respectively, two ports 254 and 55.

i The op'eration no'fsthe *device isas follows AStarting 'with thejpartsin the `position indicated in Figure 1, and Sassuming -that itis deto the left. the operator rotates handle I to draw the nut 9 toward bracket 6, thus, through the lever I0 and link I3, moving the sleeve valve I4 tothe left-say, to the position indicated in Figure 4.

It Will be apparent that this motion of the sleeve brings ports 48 and 50 kintoalignment with groove 26 and brings ports"53-and55 into alignment with groove 21, at the same time causing dports 52 and 54 to be covered by the central Y iportionfof thepiston and ports 49 and 5I to be covered by the left vhand end portion thereof. Thus `huid under -pressure is permitted to flow from'piper1zand-recess I 6 through port 48, groove '26, port 50, recess 'I8 and pipe 20 to the right handgendofcylinder 2I to move piston 30 to th left. 'i l Simultaneously, the passage from the left hand end of cylinder 2I through pipe 22 permits -the Vdischarge of vfluidthrciughrecess .1139, .ports '53, groove'21,port55,andpipez24 to the receiving tank lor sump C F, fia-hue fpermitting `the" leftvvard movementl ofpistonil.

The motion rofl-piston .'34, of course, Y'moves piston 3B 1li-n the same' direction, :and fsowfdrces and Vconnection article. Y -Y Y This `motion of fthe fpistons :continues iuntil theparts reach the positions indicated in Figure 5, in which the piston valve 25 has moved until its lright hand V end againv covers :ports 48 .and .54,

its 'central portioncovers ports52, 53,*'54 and .155,

and its left handfen'cl still covers ports 49"*and 5I. In this position, no rliiidfcan now-through vthe Lcontrol V:and the fparts `l"are brought `to rest.

In Figure f-'6, the Vv"sleeve 'hasbeen moved i in the opposite direction-itc v=the Iright-fitoA a 'position *beyond thatA Which'it had roccupied-at itsmore or less central original position of Figurelfand 'it 'isV apparent lthatiiluidmay -now 'f'floW' fromI pipe I1 and Vrecess -I 6,through'port-4 9,-groove'f2r1, port 5I, recess I`9,andpipe @22 Ito 'the left hand end of cylinder 2|, and that iluid may now be-dis'-y charged from' theright hand-endfofthisY cylinder *throughV pipeZ Il, recessI-, portl5'2,y groove'26; port 54, recess 23, and pipe 24 `-to thes`ump T. The uid'novv Will'movepiston 30, together With pis- Ytons 35 and43 to-the-rig`ht -untilthepiston -valve 25 has reached'thelpositionfshownfin Figure 7, wl'iere once -`againaall 'the ports are closed.

'Figure 18' shows"atsetting of the sleeve f valve to move the pistons still mvfarther -to Athe rightf--vto theirfurthest distance A"in this direction. The :communications :established and directions of 'motion are thesamefaszinfligure.

VEven where-'the sleeve has -`been `Inovedtofthe extreme position shown in Figure 48, Where ports 52iand' 53 V'are V'both'incommunication 4with recess I8, thefparts function "correctly :because the centralporticn :of the piston *'25 covers port 54 `so long-as groove-26 is in'commun'ication Withipo'rts 52 and 54, so that there can be no bypassingof the fluid lWhich would interferewiththe -opera tion. y

"To return the parts v`to their original :position it is only-necessary@tot-returnthesleeve vvalve to its initialr position, fas-inl Figure '1,1When the fluid passesthrough-the -various' passages :asit d-id in Figure 4, until/'thefpistonf25resumes its original neutral position.

'From the aboveitfis-:apparent:that-ianyfmotion "of the `t's'leeve :valve "Will Vcause a corresponding motion of the several pistons, the parts always coming to rest when piston valve 25 is in such a position that its ends cover ports 48, 49, 50 and and its central portion covers ports 52, 53, 54 and 55 and that the amount of motion imparted to piston 43 therefore is directly proportional to the amount of motion imparted to the sleeve I4.

The actual distance travelled by piston 43, of course, may be varied by the proportioning of the diameters of the cylinders 33 and 42, while the force which as applied can be determined by the areas of the pistons in these two cylinders, as well as that in cylinder 2|, and the pressure of the uid supply.

Both the piston valve 25 and the sleeve I4 are so arranged that all pressures acting upon them are balanced, so that the sleeve may be moved by any motion which is suiicient to overcome the friction between the piston 25, the sleeve I4, and the cylinder I5. Also, the ports are opened and closed somewhat gradually so that the smoothness of operation is assured.

It will be observed that if the motions of the sleeve I4 and of the piston valve 25 are very short, ports 52 and 53 can be merged into a single port, and so likewise can ports 54 and 55, but this can only be done when the length of the combined port will be of less length than the distance between recesses I8 and I9, because otherwise iiuid will be by-passed between these recesses interfering with the operation of the apparatus.

While I have described the illustrated embodiment of my invention in some particularity, ob-

viously many other embodiments, modifications and variations will occur to those skilled in this art, and I do not. therefore, limit myself to the precise details shown and described herein, but claim as my invention all embodiments, modications and variations coming within the scope of the appended claims.

I claim:

1. An hydraulic control device comprising a source of fluid under pressure, a cylinder, a load moving piston movable therein, a piston rod xed to the piston and carryingv a cylindrical valve part provided with two annular grooves, a sleeve slidably fitting the exterior of the valve part carried by the piston rod and having ports therethrough angularly disposed about the sleeve, a fixed cylindrical casing slidably receiving the exterior of the sleeve and having four recesses on its interior which may selectively be brought into alinement with the ports through the sleeve by the axial movement of said sleeve, one said recess being connected to the discharge side of the source of fluid under pressure, another recess being connected to the intake side of the source of fluid under pressure, a third recess being connected to one end of said cylinder, the fourth recess being connected to the opposite end of said cylinder, and positive connections between the piston and its load, said two annular grooves being selectively registerable with certain of said sleeve ports and certain of said recesses to effect a movement of said piston rod in a selected axial direction.

2. An hydraulic control device comprising a source of fluid under pressure, a cylinder, a load moving piston movable therein, a piston rod connected into the piston and extending beyond the cylinder, a cylindrical valve part fixed to said piston rod and having two annular grooves, a tubular sleeve slidably fitting said valve part and provided with ports therethrough annularly spaced about the Sleeve, a fixed valve cylinder slidably receiving the sleeve and having two axially aligned recesses connected with the opposite ends of the cylinder, the valve cylinder having two additional interior recesses out of axial alignment with each of the two first mentioned recesses and with each other, and connections between one of the last mentioned recesses and the outlet side of the source of fluid under pressure and between the other of the last mentioned recesses and the intake side of the said source of fluid under pressure, said two annular grooves being selectively registerable by relative movement of said sleeve and said cylindrical vvalve part on said piston rod, with certain of said recesses to eiiect an axial movement of said piston rod.

ANTHONY L. LADO.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 160,327 Hutchison Mar. 2, 1875 591,768 Kaselowsky Oct. 12, 1897 689,186 Heisler Dec. 17, 1901 863,405 Koelkebeck Aug. 13, 1907 2,038,272 Ernst Apr. 21, 1936 2,140,037 Swisher Dec. 13, 1938 2,221,150 Rebeski Nov. 12, 1940 2,363,179 Harrington Nov. 21, 1944 2,374,545 Ingres Apr. 24, 1945 2,380,575v Brown July 31, 1945

Images