US1570097A - Fluid-pressure-control system - Google Patents

Description

J. W. SUMNER ET AL FLUID PRESSURE CONTROL SYSTEM men of rack Bind/'an of James iV. .5w-nnerlden G. Rayburn AAAAAAAAAA ;Q 2

' 44 4a TAM. ATTORNEYS. 1

Jan; 1 9 1926.

' A 1,570,097 J w'. SUMNER ET AL FLUID PREsxsuRE CONTROL sYsTm Filed June v', 1925 sneets-sheerz Patented n19, 1,926.

uNrri-:o STATES 1,570,1197 M11-:tirortica.J

`TAKES Bm mALDEN G. AYBUBN, 0F LOB ANGELES, CALIFORNIA', A8-

BIQNOBS T0 MOBY WINSHIP, IFRANCISGO,I CALIFORNIA.

rLUIDnEssUnn-con'rn'on sYsrma. s

Application led June 7,

To cZZ fwwm, it may concern."

Be itknown that we, JAMES W. SUMNER and ALDEN G. RAYBURN, citizens of the United States, and both residents of the city of Los Angeles, in the county of` Los Angeles and State of California, have invented a new and useful Fluid-Pressure-Control System, of which the following is a specification. y

rilhis invention relates to a system for op I era-ting a mechanism by the aid of liuid pressure, and. more particularly to such a system iii`4which Kthe extent of movement of an element moved by fluid pressure may be manually controlled by moving a controlling device, 'and in which this extentV of movement is dependent upon the extent of movement of the controlling member.

Such a system is described and claimed in an application, Serial Number 599,777, -led Nov. 9, 1922 in the naine of James W. Sumner, and entitled Power steering mechanism.lv In that mechanism7 a source of fluid pressiuge for operating the device is describethacomprising an engine driven pump.' It isi-onge of the objects of our invention to provide a simpler and less expensive source of fluid pressure. It is another obj ect of our invention, in this connection, to provide a pneumatically operated device to replace the pump of the prior ap lication.

Since the source of, power for creating the fluid pressure is itself operated'by fluid pressure, it is possible to control the entire mechanism by controlling 4either one or both of the fluid pressure devices', and thereby ensure against possible failure. It is thus another object of our invention to provide a form of double control for lsuch a mech-v anism. y

In the form of the invention which we `illustrate, ythe control mechanism is used as a power steering device for` road vehicles, such as automobile trucks. In that form, the device of our invention has many advantages; for example the suction createdin the intake of the internal combustion engine for driving thc-vehicle may be used for operating'a pneumatic cylinder, the piston of which in turn is connected to a fluid pressure piston for generating the working fluid pressure. y, f

Our invention possesses other advantageous features, some of which with the fore- 1923'." semi 'im siam. y

gomg, will be setforth at length in the following descr1pt1on, where we shall outline in full that form of the invention which we have selected for illustration in the drawingsaccompanying and forming part of thev present specification. Although we have shown in the drawin s but one embodiment of our invention, we o not Adesire to loe-limited thereto, since the invention as expressed in theclaims maybe embodied in other Figa 2 and 3 are diagrams illustrating i one phase of the mode of operation of the device shown in Fig. 1;

Fig. Liis an outline view of the device as applied to an automobile truck, the front end only of the truck being indicated, and parts thereof broken away; and Fig. 5 is a sectional view, along plane 5-,5 of Fig. 1, showing a detail of a valve construction used in this form of device.

In the present instance, the control of the mechanism is effected by-manually rotating a handwheel 11, and the element the movement of which is thus controlled, is shown as a drop arm 12 that is arranged to oper- -ate a drag link 13 for steering the front wheels 14 of a motor vehicle 15. The steeringelements, including link 13 and arm 12, may o erate in a well-known -manner to move t e front wheelsy 14 in either direction, and it is considered unnecessary here to enter into further details in this regard. z"

The steering wheel 11 may be of conventional design, as is common in motor vehicles, and may berovided with a shaft 17 to which it is rigi ly attached and which is supported in a column 16 appropriately fastened to vehicle 15. Angularmovement of the steering wheel 11 sets into operation a fluid pressure mechanism for moving the are so arran ed that when the rod 25 is moved in one irection, say toward4 the right, then the right hand cylinder 23 is active to create a pressure in the space `3() between the cylinder 23, while at t e left hand cylinder 22, the pressure is released in the s ace be- -tween the piston and the left hand ead 29 of cylinder 22. The reverse effects are obtained when the rod 25 moves toward the left. It would of course be ossible to relace the two single actingcy inders witha Idouble acting one in which the chambers on both sides of the pistons are active and corres ond to the two v active spaces just descri ed.

The active pressure spaces or chambers 30, as well as all spaces leading thereto,

are maintained filled with a fluid such as oil so that the exertion of a pressure in these chambers may be immediately effective at the place where it is utilized to produce mechanical motion. In order to insure that all these spaces will be filled in spite of leaks or the like, We provide oil reservoirs 31 above the cylinders 22 and 23, which are in Comunication with the active' spaces only when the istons 24 are in their extreme pressure-re easing positions, as by the aid of a small aperture 32. After the piston 24 moves far enough to place this aperture into communication with the other side o the vc linder, as shown in the drawings, oil will geeallowed to drip into this space, but will be returned to the reservoir 31 on movenient ci the piston in the reverse direction,

and in this way there is no loss of the liquid. ln order to ensure complete return, a large aperture 33 at the end of the cylinder connects to the reservoir 31.

iipes 26 and 27 connect to the pressure chambers 36 and serve to,=conduct the oil under pressure to the place where it is useful to produce movement of the drop arm l2. For this pu ose, a double' cylinder 34 is used, in Whic there are two pistons 35 and 36, connected to a common rod 37. Movement of the istons in either direction is eected by duid under 1pressure being forced against one piston, wh' ethe duid from the other piston is withdrawn. Pipe 38" supplies this iluid to the .top pressure chamber 39 and piston 35, while pipe 4G accomplishes the same result for the lower chamber 41 and piston 36. iDipe 38 leads to cylinder 22 through a valve 42 and pipe 43, while pipe 40 leads to cylinder 23 through thepipe` 44, valve 42 and pipe 45. It is thus evident that a force acting to move rod 25, connecting the pistons 24, say to the left, will torce iluid under pressure through pipes 43 and 38 'and thereby urge piston 35 in cylinder 34 downwardly, while at the same time, fluid is urged to return from chamber 41 through pipes 40, 44 and 45 to the cylpiston and the ri ht hand head 28 ofinder 23. A reverse movement of rod 25 will cause these effects to be reversed, as isl chanical connections may be used to effect this result, we show a form in which the rod 37 'carries an enlarged seat 47 for rotatably seating a Hat slotted disk 46. The slot A 48 of the disk accommodates an arm 49 which is lmechanically connected to the arm 12 so that these arms form a bell crank lever mounted on shaft 5() which may be ap r0- priately journaled. The cylinder 34 an its associated parts are preferably mounted near or on the steering column 16. The slotted disk arrangement as the rod 37 moves, serves to rotate the arm 49 and thereby the arm 12.

The force that is necessary to operate the piston rod 25, is conveniently supplied by a vacuum cylinder 51 which is located between the two cylinders 22 and 23, and which operates on one or more pistons 52. ln the present instance the vacuum cylinder 51 has three compartments 53, 54 and 55, and three pistons 52. Due to the multiplication of cylinder compartments, even a relatively small difference in ressure is suiiicient to exert a comparatively large force on piston rod 25,.since all the pistons present in combination a very large surface to the duid pressure. We find it advantageous to utilize thevacuum produced in the intake manifold 56 oi. the driving engine 57. Foithis purpose a pipe manifold 58 connects to each'o the cylinder compartments atone side of the pistons 52, and a similar manifold 59 connects to each com.

pertinent on the other side of pistons 52. ln order to exert a force say to the right on rod 25, manifold 59 is connected to the intake manifold 56, and manifold 58 is connected to atmosphere. rlhere is thus a preponderance of pressure on the left hand sides of pistons 52 and` av corresponding force is exerted toward the right. ln order to create a i'orce tending to move the rod 25 to the left, the manifold 58 is connected to intake manifold 56, while manifold 59 is connected to atmosphere.

rllie valve that controls these connections is illustrated at 60, and comprises a cylindrical valve body 61 at opposite sides of 'which enter pipes 62 and 63 connecting respectively to the manifolds 58 and 59. rotatable valve member 64 is disposed in the body 61 and in the position shown, shuts oli the passageways 65 and 66, leading respectively to the intake manifold 56 and to the atmosphere. ln case the member 64 be rotated in a clockwise direction, passage` way 66' will be placed in communication 130 all axially moved. Rollers 76 we may for with pipe 62,' and p moveto the ri ht. A' reverse movement of member 64 will have the "op osite eifect.

v'In neutral position as shown, t e air in the cylinder chambers 53, 54, and `55 is trapped, "and the piston rod 25' remains in position.

, I In order to-make "certain `that/the'pis'ton rod may be maintained in any inter-l nediate position, as well as end poitions, the valve 42 hereinbefore men- ,ioned, iswprovided. Thisl valve has a -stem 67 mechanically connected with valve ymember 64. This'stemcarries a' pair of members-68 that close thepassageway's between pipes 38 and 43, and also between pipes 44:; and 45, when the member 64 isv maintained in position, so long as valves 42 and 60 are in their neutral positions.

.The movement of steering wheel 11 to the right or left is caused to operate both valves 42 and-60 so as to set'into action the agencies described hereinbefore.` The arrangement is furthermore such that lthe closing of these valves, or rather the bringing them to neutral position, is eifected by the movement of the steering ar to a osition corresponding to that of w eel 11. n other words,.for every setting of wheel 11, there corresponds but one stableposition of arm 12, and the movement of the arm 12 to this osition is coincident. with the .closure of t ese valves. I

In order to effect these results, an arrangement somewhat similary to that 'disclosed in the prior Sumner application hereinbefore identified may be used. A collar 69'is splined to the steeringl wheel shaft 17 so that there may be relative axial movement between .them -but no relative vrotational movement. A circular rack 70 isl cut on the exterior ofthis collar, which is adapted to-engage` a pinion 71 rigidly fasteiied to the shaft 72 that serves to operate the v-valves 42 and' 60, as diagrammatically indicated`by the dot-dashl hne 73.v It is evident 'thatxmere rotation of rack 70 is inl sufiicient to cause rotation of fpinion 71, and

that axial movement thereo is necessary.

For producing vthis axial. movement the collar' 69 isprovided with a depending por; tion 74in which are cut 'one or more slanting groovesfor slots-7 5 (see Figs.` 2 and"3)". These roo'ves form an inclined plane by the ai 4of which the collar 69 may be way 65 with-pi l For this condition the red 25 lthe"presentv`consider as having axes radial with y to the axis of the shaft 17, en in grooves .75A and serve to provi e a surface @n whichthe grooves mayslide.

if the '70 is lrotated in 'a direction represented bythe developed arrow 77, and assuming that roller 76 is stationary, then fthe rack is forced to move vin a downward direction, as represented by arrow 78. This downward movement lin turn causes rotation of shaft 72'in a counterclockwise direction; andvalve 60 moves from' its neutral position Vto connect'manifold 58 toy the.

Y '7o Now referring to' Fig. 2,it is evident that rintake manifold 60, and manifold 59 to thc atmosphere. f A force is thus exerted toward the left inv cylinder 51, and the oil cylinder 22 creates a fluid'pressure. This fluid pressure'exerts a force downwardly against piston 35'in cylinder 34, and there is a tendency to rotate the dro arm 12 in a counterclockwise rotation. of the wheel llyin vthe opposite direction will reverselthese effects.

While thus far in our discussion'we have assumed thatrollers 76 were'located on stationary axes, they are in fact supported 'with their axes radial, on a rotatably mounted shaft 18, which is coaxial with the v steering wheel shaft 17. This shaft 18, which is vappropriately journaled in the steering column 16, as by the roller bearings 19 and 20, and the roller step bearings 21, is mechanically connected with the drop arm 12 insuch a way that motionl may be transmitted from one t'o the other.y This connection may be? rovided'by any ty e of .gearing for examp e, and is rovidedJ for the purpose of restoring the va ve 60 as well y as valve 42 to the neutral position as soon as the dro arm 12 reaches a definite position that 1s dependent upon the extent of movement of'th'esteering wheel 11. In order to comprehend how this is accomplished. y

attention isinvited to Fig. 3, in which it is assumed that the slot 75 1s now stationary and corresponds in angular osition with that of the steering wheel 11. he mechanical arrangement is such that the shaft 18, rotated indirectly through the steering devices, has amovement in the same direction as that in which wheel 11v was moved. Therefore arrow '79, parallel toarrow 77,

re ro ers 76. It is evident from Fig. 3 that the sleeve -69 will be thereby forced upwardly, 'as indicated by arrow 80. lThis vupward movement of sleeve '69 continues until the valve60 has been returned toits original position, which correspondsjto the ooni Iovement `resents the directlon" of-movement ofthe Furthermore, as. in the -prior application,

the slots 75 aresomewhat limited in extent, so that in case the pressure. fails, `the rollers 76' soon reach the end of their travel in the slots uponl continued rotation of wheel 11, and shaft 18 is manually rotated and thereby the drop arm 12. AIt is thus evident that the direction of movement of valve 64 as well as its extent, is a function of the extent of relative movement between the shafts 17 and 18. If the shafts move in unison, then valve 64 remains in its inactive or neutral position, whereas relative movement of the shafts in either direction causes a movement Although any k'well-known form of mechanical connection may be provided benection in a diagrammatic manner, the dot- Lil dash linel 83 is used.

This drive may be made reversible by making the worm 81 of sufiicient great pitch, so as to permit wheel 82 to drive the worm. However, it may be left irreversible.; that is, in order to ermit arm 12 to'move, the worm 81 must rotated by a. force at least great enou h to overcome the friction between it an the wheel 82, after which the shaft 50 is free to i rotate this wheel. -How this affects the operation of the device may become evident from a brief review ofthe various steps in the steering control.

Let us assume that the wheel 11 is rotated in such a direction thatihe valve member 64 moves counterclockwise from the neutral position shown. At the same time, valve 42 moves to establish communication between cylinder 34 and cylinders 22 and 23. The piston rod25 has then a tendency to move to the left, since manifold 58 is connected to the intake manifold 56 through valve 60. This places the fluid in cylg'nder 22, Vpipes 43, and 38, and chamberfl in cylinder 34 under pressure, and a torque is exerted to move arm 12 in a counterclockwise direc tion. However, this movement may be temporarily prevented in case worm 81 on'shaft 18 forms anvirreversible drive. This shaft 18 is at present"`stationary, and locks the wormswheel 82 against movement. This condition continues until the steering wheel 11 is moved far enough to cause rollers 76 to reach their limit of movement; from this point on the shaft 18 may' be moved by the wheel 82, and it is kept 1n step 'wlth shaft 17. In case the pitch of worm 81 is great enough, the shaft 18 is driven even before the rollers 76 reach the end of the slots '7 5;

in this way the shaft will ultimately bring i the rollers and slots to a position where the valves 60 and 42 are closedl asin .the figure.

v described.

steering'wheel 11 is againmoved, when the same series of ,operations will occur as just ing the member, movable means for controlling the operation of said device, means whereby the extent of movement of lthe controlled member is limited by the extent of movement of the controlling means and means for creating the Huid pressure, comprising a pair of Huid ressure? cylinders, means whereby one o .the cylinders is caused to exert a force so as to a Huid pressure in the other cylin er, and means connecting the other cylinder with the fluid pressure device. 1 l

2. In a fluid pressurefcontrol system, a pair of fluid pressure cylinders, one of said cylinders being arranged to sup ly the power to produce fluid pressure in t e 'other cylinder, means whereby said Huid pressure may serve to produce a mechanical movement,4 and' means for simultaneously controlling the passageways for both cyl-- inders, whereby there will be an interruption in the passageways between the pressure cylinder and the seat of mechanical movement simultaneously with the interruption of the power cylinder operation.

3. In a fluid pressure control system, a vacuum cylinder ada ted to be connected tothe intake manifol of an internal combustion engine, a pressure cylinder operated by the vacuum cylinder, means for utilizing the ressure thus created in the pressure cylin er for producing a mechanical movement,j and means for simultaneously controlling the passageways for both cylinders, whereby there will be an interruption in the passageways between the pressure cylinder and the seat of mechanical movement; simultaneously. with the interru tion in the operation of the vacuum cylin er. v

4. -In a iuid pressure control system for controlling the movement of a member, a fluid pressure device for movin the member, a pair of fluid pressure cy'nders, one arranged to operate vthe other to produce in said other cylinder the Huid pressure for@ moving the member, and means .for controlling the movement of -the member, comprising a plurality of valves controlling the passageways from both cylinders, means f r to their inactive or neutral positions, whereby the extent of movement of the member is determined by Vthe extent of movement of the valve operating means, and whereby there will be an interruption yin the passageways between the pressure cylinderl and the seat of mechanical movement, simultaneously with. the rinterruption in the operation of the force exerting cylinder. f

5. In a fluid pressure power steerlnl mechanism for a vehicle, operated by 'an n. ternal combustion engine, a vacuum cy1m`` der adapt-ed to be connected tothe intake manifold of the engine, a pressure cylinder operated by the vacuum cylinder, a steel'a ing arm operated by the fluid pressure cre' ated in the pressure cylinder, and means for simultaneously controlling vthe passageways for both cylinders, whereby there will be an interruption vin v the .passageways between the pressure cylinder and the steering arml simultaneously with the interruption in the operation of the vacuum cylinder.

6. In a fluid pressure power steering mechanism for a vehicle, a steering arm, a fluid pressure device for moving the arm, a pair of fluid pressure cylinders, one arranged to operate theother to produce in said other cylinder the fluid pressure for Vmoving the steering arm, and .means for controlling the movement of the arm, comprising a plurality of valves controlling the passageways from both cylinders, a steer ing wheel arranged to operate said valves simultaneously, and means, operated in response to the movement of the steering arm to return the valves to their inactive or neutral positions, whereb the extent of movement of the arm is etermined by the extent vof movement of the steering wheel, and wherebythere will be an interruptionin the passa eways between the pressure cylinder4 and t efluid pressure device, simultaneouslywith the interruption in the operationof the force exert' c linder.

7. In a ui pressure power steering mechanism, a pair of coaxially mounted shafts, a steerlng armmechanically connected to one of the shafts, means for manually rdtating the other shaft, a fluid ressure cylinder, a valve for connecting either side of the cylinder with a source of Huid pressure, means whereby 4the relative move` ment` between the shafts determines the clire'ction and' extent of o eration of the valve, so as to determine the irection of operation of the cylinder, `and fluid pressure means operated by the cylinder form'oving the steering arm.

8. In a power steering mechanism for a vehicle operated by an internal combustion engine, -a pair of coaxially mounted shafts, a steeringarm mechanically connected to .oneJof the shafts, a steering wheel connected to the othershaft, a .vacuum cylinder, a valve for connecting either side of the cylinder with the' intake manifoldof the engine, means whereby therelative movement between theshafts-determines the direction and extentfof foperation of the valve, so as to determine the direction of operation of the cylinder, 'acylnder operated by the vacuum cylinder to produce a fluid pressure, and a'iluid pressure device connected to the fluid pressure cylinder for moving the steering arm.

9. Ina power steering mechanism for a vehicle operated by an internal combustion engine, a -pair of coaxially mounted shafts, a steering arm mechanically connected to one of the shafts, a steering wheel connected to the other shaft, a vacuum cylinder, a valve for connecting either side of the cylinder with the intake manifold of the engine, means whereby the relative movement be- ,tween the shafts determines the direction and extent of o eration of the valve, so as to determine the 'rection of operation of the cylinder, a cylinder operated by the vacuum cylinder for creating a fluid pressure, a fluid pressure device operated by the fluid pressurelto move the steering arm, and means connected to the valve for interrupting com-V jnunication 'between the fluid pressure c linder and the fluid ressure operated evice when the valve 1s in it inactiilze posi'- tion correspondingl to no re ative sp ace- `ment betweenthe coaxial shafts.

10. In a fluid pressure device, an air cylinder, partitions in the cylinder forming separated cylinder chambers, a piston rod extending through all the chambers, pistons in the chambers, a ai of li uid cylinders, one

at each end of t e air cyhnder, and pistons F for the cylinders fastened tothe rod. 1

In testimony whereof, we have hereunto set our hands.

, y JAMES W. SUMNER.

- G. RAYBURN.

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