US3683749A - Hydraulic control means - Google Patents

Abstract

A hydraulic control device for controlling the operation of a reversible hydraulic motor device, such as a hydraulic ram, which has a deactivating valve assembly which provides a fluid bypass passage across the fluid inlet and passages of the ram cylinder to render the hydraulic ram inoperative in the event of malfunction of the control device. An apparatus for operating a controlled member, such an aileron, spoiler or the like, of an aircraft which includes a plurality of hydraulic motor devices having separate control means for individually controlling the motor devices, the control devices having means for deactivating the motor devices upon the malfunction of the control devices so that the motor device whose control device has malfunctioned or is inoperative will not impede the operation of the controlled member by the other motor devices whose control devices still function properly.

Description

United States Patent Bayles [54] HYDRAULIC CONTROL MEANS [72] Inventor: Fred R. Bayles, Dallas, Tex.

[73] Assignee: LTV Eleetrosystems, Inc., Dallas Tex.

22 Filed: June4, 1970 211 Appl.No.: 43,325

Primary Examiner-Edgar W. Geoghegan Att0rney-Walter J. Jagrnin and James D. Willbom I14 I26 1317 V [4-51 Aug. 15, 1972 ABSTRACT A hydraulic control device for controlling the operation of a reversible hydraulic motor device, such as a hydraulic ram, which has a deactivating valve assembly which provides a fluid bypass passage across the fluid inlet and passages of the ram cylinder to render the hydraulic ram inoperative in the event of malfunction of the control device. An apparatus for operating a controlled member, such an aileron, spoiler or the like, of an aircraft which includes a plurality of hydraulic motor devices having separate control means for individually controlling the motor devices, the control devices having means for deactivating the motor devices upon the malfunction of the control devices so that the motor device whose control device has malfunctioned or is inoperative will not impede the operation of the controlled member by the other motor devices whose control devices still function properly.

5 Claims, 4 Drawing Figures PATENTEDAUB 15 m2 SHEET 1 [IF 3 .v ,..,c R N L WT EV! r Rm EN; mmm mm NON Mom mom PATENTEDAus 15 1912 saw a or 5 INVE/VTUR FRED R. BAYLES ATTORNEY PATENTEDAUG 15 m2 3.683; 749 sum 3 or 5 Fig.3

IIVil/E/VTOR FRED R. BAYLES ATTORNEY HYDRAULIC CONTROL MEANS This invention relates to hydraulic control devices and to hydraulic apparatus for controlling the operation of a plurality of hydraulic motor devices used to operate a controlled member.

An object of the invention OS to provide a new and improved hydraulic control device for controlling the operation of a hydraulic motor device.

Another object is to provide a hydraulic control device for a reversible hydraulic motor means which is caused to operate in one direction when hydraulic fluid under pressure from a hydraulic pressure system is circulated thereto in one direction and to operate in the opposite direction when the hydraulic fluid is circulated thereto in a second direction, and which is held against operation in either direction when the circulation of hydraulic fluid to or from the motor means is prevented.

Still another object is to provide a hydraulic control device, of the type described, having a control valve assembly which is operable selectively to admit fluid under pressure to a first or second fluid passage means of a hydraulic motor means and permit exhaust of hydraulic fluid from the other of the first and second flow passage means, or to prevent flow of hydraulic fluid to or from either of the first and second flow passage means of the hydraulic motor means; and a deactivating valve assembly which is responsive to malfunction of the control valve assembly for providing a first bypass flow passage between the first and second flow passage means of the motor control hydraulic motor means to deactivate the motor means and permit a controlled member normally operated by the motor means to be moved by other forces.

A further object is to provide a hydraulic control device, of the type described, which also has a bypass valve assembly, operatively associated with the control valve assembly and operable when the hydraulic pressure source or system fails to provide hydraulic fluid under predetermined pressure to the hydraulic control device, for establishing a second bypass flow passage between the first and second passage means of the hydraulic motor means.

A further object is to provide a new and improved hydraulic control device for controlling the operation of a hydraulic ram having a piston reciprocable in a cylinder and first and second passage means at opposite side ends of the cylinder and opening to the cylinder on opposite sides of the piston, the control device being operable selectively to admit hydraulic fluid under pressure to either of the passage means and permit exhaust of the fluid from the other of the passage means, in order to cause movement of the piston in one or other direction in the cylinder, and to prevent flow of hydraulic fluid to or from both of the passage means to prevent flow of hydraulic fluid to or from either end of the cylinder through the passage means whereby the piston is effectively locked in any adjusted position thereof relative to the cylinder, the control device including a deactivating valve assembly which is operable by fluid pressure upon the malfunction of the control valve assembly to provide a first bypass flow passage between the oppositeends of the cylinder whereby the piston is freed for movement in either direction in the cylinder.

A still further object is to provide a hydraulic control device of the type described wherein the control valve assembly includes a valve member or spool longitudinally movable in a body means of the control device by means of a reciprocable control member or rod by pistons exposed to hydraulic pressure which exert predetermined forces on the valve spool to cause the valve spool to move with the control rod, the control rod being movable relative to the valve spool if the valve spool is held against movement by a force which exceeds the predetermined value, the control rod and the valve spool having cooperative means for providing hydraulic fluid under pressure to the deactivating valve assembly upon occurence of relative movement between the control rod and the valve spool.

An important object of the invention is to provide a hydraulic apparatus or system for controlling operation of a plurality of hydraulic motor devices used jointly to operate a controlled member which apparatus employs separate control devices for individually controlling operation of the individual motor devices.

Another object is to provide a hydraulic apparatus or system, of the type described, wherein each control device has means for deactivating the motor device controlled thereby upon the malfunction of the control device in order that a motor device whose associated control device has malfunctioned or is inoperative will not impede or hinder the operation of the controlled device by the other motor devices whose control devices are functioning properly.

Additional objects and advantages of the invention will be readily apparent from the reading of the following description of a device constructed in accordance with the invention, and reference to the accompanying drawings thereof, wherein:

FIG. 1 is a sectional partly schematic view, with some parts such as seal means omitted. for clarity of illustration, of the hydraulic control device embodying the invention for operating a hydraulic ram and showing the control device in position preventing flow of fluid from either end of the cylinder and causing the piston of the hydraulic ram to be held against movement by the hydraulic fluid;

FIG. 2 is a view similar to FIG. 1 showing the valve spool of the control valve assembly of the device held against movement in the body means of the device and its control rod displaced to the right relative to the valve spool, and the deactivating valve assembly being in actuated position and providing a bypass passage between opposite ends of the cylinder of the hydraulic ram;

FIG. 3 is a view similar to FIG. 2 showing the control rod displaced to the left relative to the valve spool and the deactivating valve assembly in actuated position; and,

FIG. 4 is a fragmentary perspective view, with some parts broken away, showing the: control devices embodying the invention in use for controlling separate hydraulic rams for actuating a controlled member, such as the illustrated aileron on an aircraft.

Referring now to'the drawings, eachhydraulic control device 10 embodying the invention is shown as used to control the operation of a hydraulic motor. Two or more such motors 11 and 11a, FIG. 4, individually controlled by separate devices and 10a,

respectively, are shown in use to operate a control member of an aircraft, such as anelevator 12, spoiler or the like. The hydraulic motors are of the hydraulic ram type having cylinders 14 in which are reciprocable pistons 15 whose rods are pivotally connected by means ofclevises 16 andpins 17 to levers 18 rigidly connected to arotatable shaft 19 to which the control member is rigidly secured. Thepins 17 extend throughsuitable slots 20 of the levers.

It is desirable and necessary in the event of a malfunction of acontrol device 10 of one of the motors, that such motor be deactivated or rendered inoperative so that it will not interfere with the operation of the aircraft control member by the other motor or motors whose control devices are still in operative condition.

Each of the control assemblies includes a control valve assembly CVA, operable by the usual auto pilot and a pilot manual override control of an aircraft, not shown, which selectively causes hydraulic fluid under pressure, from the hydraulic fluid circulating system of the aircraft, to be admitted into one end or the other end of the hydraulic cylinder 14 while allowing flow of the hydraulic fluid from the other end of the cylinder back to the fluid return line of hydraulic system when the valve assembly is in either of its opposite operating conditions and which prevents flow of hydraulic fluid from either end of the hydraulic cylinder when the valve assembly CVA is in its neutral or intermediate position; a bypass valve assembly BV which isolates the control valve assembly CVA from the pressure side of the aircraft hydraulic system when the pressure of the hydraulic fluid is below a predetermined value; and a deactivating valve assembly DVA which, when the control valve assembly is damaged or malfunctioning, provides fluid communication between opposite ends of the hydraulic ram cylinder 14 so that the piston is free to move within the cylinder.

Each of thecontrol assemblies 10 includes a housing having achamber 26 which is closed at one end by aclosure 17. Acontrol shaft 28 suitably joumaled in opposite walls of the housing extends through thechamber 26. The control shaft is rotatable about its central longitudinal axis, being connected at a location externally of the housing to the autopilot linkage and also to the pilot manual override control. The control shaft has rigidly secured thereto anarm 30 whose outer end is bifurcated to provide a pair of legs 31 which are disposed in an externalannular recess 32 of areciprocable control rod 33. It will be apparent that when thecontrol shaft 28 is rotated in a counterclockwise direction through a limited angle, the engagement of thecam surfaces 35 of the legs 31 with theannular shoulder 36 of the control rod defining one end of theannular recess 32 of the control rod causes the control rod to move to the right and that when it is pivoted in a counter-clockwise direction the engagement of thecam shoulders 37 of the legs with theannular shoulder 38 of the control rod defining the other end of theannular recess 32 causes the rod to be moved to the left.

Thecontrol rod 33 extends through atubular valve spool 39 slidably mounted in atubular valve body 40 disposed in a longitudinal passage 41 of the valve body which extends perpendicularly to the axis of rotation of thecontrol shaft 28. The valve body is held in proper position in the passage 41 by anut 42, threaded in the enlargedportion 43 of the passage 41, whose inner surface bears against theouter end surface 44 of the valve body and holds the innerannular surface 45 of the external annular flange 46 of the valve body against the annular stop shoulder 47 of the housing.

The valve body is provided with a pair of internalannular grooves 51 and 52 which are aligned with the externalannular grooves 53 and 54, respectively, of thevalve spool 39. The aligned pairs ofgrooves 51 and 53 and 52 and 54 define annular hydraulic fluid return passages R1 and R2, respectively. The hydraulic fluid return line or conduit 54a of the hydraulic system of the aircraft is connected to thehousing 25 and opens to the internalannular groove 56 of the housing which is aligned with and in communication with an externalannular groove 57 of thevalve body 40. Thegroove 57 is maintained at all times in communication with the fluid return passage R2 by aport 60 of thetubular valve body 40 which opens to its external andinternal grooves 57 and 52, respectively.

The housing is also provided with alongitudinal passage 62 which opens at its right end to the internal groove rt of thehousing 25 and at its left end to a similarexternal groove 64 of the housing which is aligned with and therefore in communication with an externalannular groove 65 of thevalve body 40. Aport 67 of the valve body provides communication between the return passage R1 and thegroove 65 as it opens to thegrooves 65 and 53.

The fluid return passages R1 and R2 are thus at all times connected to the exhaust line 54a of the hydraulic system. Thetubular valve spool 39, intermediate itsexternal recesses 53 and 54, is provided with an external annular recess or groove 70 which defines with the valve body an annular pressure passage P to which hydraulic fluid under pressure is transmitted from thepressure line 72 of the hydraulic system of the aircraft through the by-pass valve assembly BV when thepiston 75 of the by-pass assembly BV is in the actuated position illustrated in FIG. 1 and held therein by the pressure of the hydraulic fluid against the resistance of thespring 76. The piston- 75 is slidable in a tubular valve body 78 which is held in alongitudinal passage 79 of thehousing 25 bycap 80 threaded in the external enlarged portion 81 of the passage. The internal annular end surface 82 of the cap engages the external end surface 83 of the valve body to hold the valve body against outward movement in the passage. Inward movement of the valve body in thepassage 79 is limited by the engagement of its external end flange 340 with the annular surface 84 of the valve body defining the inner end of the enlarged portion of thepassage 79. The flange 84a is provided with adiametric slot 86 which is in communication with aport 58 of thehousing 25 which opens to theinternal groove 56 thereof. As a result of the provision of thisslot 86 and theport 58, thebore 90 of theretainer cap 80 is at all times in communication with the fluid return passage R2 and therefore with the hydraulic fluid exhaust line 54 of the hydraulic system.

Thespring 76 which biases thepiston 75 toward its non actuated position has an end portion telescoped over thespring guide 91 of thecap 80, the outer end portion of the spring engaging theannular surface 92 of thecap 80 and its other end telescoping over thespring retainer extension 94 of the piston and engaging theannular shoulder 95 provided by an external annular flange 96 of the piston.

Thepiston 75 is provided with an externalannular recess 101 which, when the piston is in the actuated position illustrated in FIG. 1, provides communication between thepressure fluid conduit 72 and the pressure passage P since thefluid pressure conduit 72 is connected to thehousing 25 and opens to an internalannular groove 104 of the housing in thepassage 79 which is aligned with and therefore in communication with an externalannular groove 105 of the valve body 78. Thegroove 105 is in communication with the internal bore orpassage 106 of the tubular valve body through theports 107. The pressure passage P is in communication with passage defined by theexternal recess 101 of thepiston 106 throughports 108 of the valve body which open to the passage P and to an annular recess orgroove 110 of thevalve body 40 which is aligned with an annular groove 111 of the housing, a passage 112 which opens to the groove 111 and 114 of the housing, anexternal groove 115 of the valve body 78 which is aligned with the recess 114 and theports 116 of the valve body 78 which open to thegroove 115 and the internal passage or bore 106 of the valve body 78.

Thehydraulic pressure conduit 72 is in fluid communication with the extreme left end portion of the passage orbore 106 of the valve body 78 by means of abranch duct 118 which is connected to thehousing 25 at itsbore 119 and which opens to the space 120 between the internalannular surface 121 of the housing defining the inner end of thepassage 79 and the inner end of the valve body 78.

When the pressure of the fluid of the hydraulic system of the aircraft exceeds a pre-determined value, the force exerted thereby against the inner end of thepiston 75 is sufficient to overcome the resistance of thespring 76 and the piston is moved to and held in its actuated position illustrated in FIG. 1.

Thepiston 75 also has a second external annular recess orgroove 125 which, when the piston moves to the left to its non-actuated position, indicated in broken lines in FIG. 1, provides fluid communication between two sets of ports 126 and 127, for a purpose to be described below, which open to the external annular recesses 128 and 129, respectively, of the valve body 78 aligned with the passages 130 and 131, respectively, of the housing and within the passage or bore 79 thereof. The groove or recess 130 is in fluid communication with a groove 132 of the housing by apassage 133 thereof and the groove 131 is in fluid communication with the groove 135 of the housing by apassage 136 for a purpose to be described below.

The grooves 132 and 135 are aligned with externalannular grooves 141 and 142, respectively, of thevalve body 40 and define therewith annular control passages C1 and C2, respectively.

The control passage C1 is always in fluid communication with the rear end of the cylinder 14 of the motor device 11 through a port 145 which extends between theannular recesses 146 and 147 of the housing which are aligned respectively with therecess 141 of thehousing 25 and an externalannular groove 148 of thevalve body 150 of the deactivating valve assembly DVA, and aconduit 151 which opens to thegroove 147 and the rear end of the ram cylinder 14.

Similarly, the control passage C2 is always in com munication with the front end of the cylinder 14 by means of aport 153 which extends between the annular grooves orrecesses 142 and 154 of the housing and aconduit 155 which opens to theannular groove 154. Thevalve body 150 has anannular groove 156 aligned with thegroove 154.

Thehousing 25 has a plurality ofports 160 which open to thegroove 141 of thevalve body 40. Theports 160 are closed by an annular land 161 of thevalve spool 39 when the valve spool is in the intermediate position illustrated in FIG. 1, the land sealingly engag ing with theintermediate seal surface 164 of thevalve body 40 to close theports 160. v

Thevalve body 40 hassimilar ports 165 which open to the annularrecess 142 of thevalve body 40 and which are closed by theland 166 of the valve spool. When the valve spool is in the intermediate position illustrated in FIG. 1 of the drawing, the land sealingly engages theseal surface 164 of the valve body to close theports 165.

It will now be apparent that if thevalve spool 39 is moved to the right relative to thevalve body 40, as to the broken line position indicated in FIG. 4, the control passage C1 is placed in fluid communication with the fluid return passage R1 since its ports 161 will now open to therecess 53 of the valve spool and thus the rear end of the cylinder 14 is placed in communication with the exhaust duct 54 of the aircraft hydraulic system. Simultaneously, the control passage C2 will be placed in communication with the pressure passage P since itsports 165 will now be in communication with the external recess 70 of the spool and therefore the hydraulic fluid under pressure is simultaneously allowed to flow into the front end of the hydraulic cylinder 14. As a result, the piston 15 will be moved to its retracted position thus pivoting the control ledmember 12 in a clockwise direction about the axis of itsshaft 19.

Conversely, if thevalve spool 39 is moved to the left, as to the broken line position indicated in FIG. 3, relative to thevalve body 40, the control passage C1 is placed in communication with the fluid return passage R2. Fluid under pressure is now admitted to the rear end of the cylinder from thepressure supply duct 72 of the hydraulic system and simultaneously the front end of the ram cylinder is connected to the exhaust duct 54 since the passage C1 is now placed in communication with the pressure passage P through its ports 161 and the control passage C2 is placed in communication with the fluidreturn passage R 2 through itsports 165. As a result, the piston 15 is moved toward its extended position and pivots thecontrol member 12 in a counter-clockwise direction about the axis of itsshaft 19.

The valve spool, during normal operation of the control valve assembly CVA is caused to move longitudinally with thecontrol rod 33 by the force of the fluid pressure from the pressure passage P which acts on the outer end surfaces of opposedtubular pistons 171 and 172.

The piston 171 is slidably mounted on a reduced portion 174 of thefront end section 175 of thecontrol rod 33 and is slidable in the enlargedleft end portion 176 of the bore 177 of thevalve spool 39. Inward movement of the piston 171 on the control rod is limited by the engagement of its inner annular end surface with the annular left end surface of themiddle section 178 of the control rod. The treaded end portion 181 of theend section 175 is threaded in a suitable threaded bore in the left end of the middle section 180. Outward movement of the piston 171 or the control rod is limited by the engagement of its outer annular end surface with theannular shoulder 183 of theend section 175 of the control rod. Inward movement of the piston 171 relative to the control rod and the valve spool is limited by the engagement of its inner annular end surface with the annulaer end surface of thecentral section 178 of the control rod and the internalannular stop shoulder 185 of the valve spool defining the inner end of theenlarged portion 176 of its central bore 177.Suitable rings 185 and 186 disposed in annular recesses of the piston 171 seal between the control rod and the valve spool, respectively.

When fluid under pressure from the pressure passage P is transmitted to theannular chamber 190 between the control rod shoulder I83 and the outer end of the piston 171 by means of apassage 193 of thehousing 25 which opens to the recess or groove 111 of the housing, apassage 194 which communicates with thepassage 193, an annular groove orrecess 195 of thehousing 25, an externalannular recess 196 of thevalve body 40 aligned with theannular recess 195, aport 197 of the valve body, an internalannular recess 198 of the valve bodyv and aport 199 of the valve spool which opens to therecess 198 and thechamber 190. An O-ring 201 seals between the piston and the valve spool outwardly of theport 199.

A plurality ofports 203 of the valve spool open to the fluid return passage R1 inwardly of theshoulder 185 of the valve spool so that the outer annular end surface of the piston 171 is exposed to the high pressure from the pressure passage P while its inner end surface is exposed to the low pressure in the fluid return passage R1. As a result, the force exerted on the piston due to this pressure differential, and in turn exerted on the valve spool due to the engagement of the inner end surface of the tubular piston with theshoulder 185 of the valve spool causes the valve spool to move to the right with the control rod when the control rod is moved to the right if the valve spool is held against movement in the valve body with a force greater than the force exerted thereon by the piston.

The othertubular piston 172 similarly is mounted on the reduced end portion 210 of the righthand end section 211 of the control rod, secured to the right hand end of themiddle section 178 by an inner end portion threaded in a suitable bore of the middle section. The piston is provided with O-rings 214 and 215 which seal between the piston and the control rod and the valve spool, respectively. Inward movement of thepiston 172 relative to the spool valve is limited by the engagement of its annular inner end surface with the internalannular shoulder 216 of the valve spool defining the inner end of the right end enlargedportion 218 of the central bore 177 of the valve spool. Pressure fluid is transmitted to theannular chamber 220 between the outer end of thepiston 172 and the annular shoulder 222 defining the inner end of the reduced portion 210 of the control rod right hand end section 21 1 through thehousing passage 193, thepassage 194, an internal annular recess 224 of the housing to which opens the right end of thepassage 194, an external annular recess 225 of the valve body which is aligned with the recess 224, a port 227 of the valve body which opens to the groove 225, anexternal recess 228 and ports 229 of the valve spool which open to therecess 228, an externalannular recess 231 of the controlrod end portion 211 to which the port 229 opens, ports 233 which open to therecess 231, and apassage 234 to which the ports 233 also open. The outer end of thepassage 234 is closed by suitable plug 235. The annular inner end surface of the piston is exposed to the pressure in the fluid return passage R2 through theports 236 of the valve spool which open to the flow return passage R2 and the internal bore 177 of the valve spool inwardly of thevalve spool shoulder 216.

It will now be apparent that if the control rod is moved from its intermediate position, FIG; 1, to the left, the force of the pressure of the hydraulic fluid exerted on the outer annular end surface of the piston 171 will cause the valve spool to move with the control rod to the left due to the engagement of the annular inner end surface of thepiston 172 with theshoulder 216 of the valve spool if the force resisting the movement of the valve spool to the right in the valve body is less than a predetermined valve which is less than the force exerted by the hydraulic fluid on thepiston 172.

If the valve spool is seized in the valve body, as due to galling of the lands of the valve spool or presence of extraneous particles between the valve spool and the valve body so that the normal operating longitudinally acting force exerted thereon by either thepiston 171 or 172 cannot move it to the left or to the right as the control rod is moved to the left or to the right, the control rod will move longitudinally relative to the valve spool. In the case of the movement of the control rod to the left relative to the valve spool from the position illustrated in FIG. 1 to the position illustrated in FIG. 3, the force exerted by the pressure fluid on the tubular piston 171 will initially resist such movement. Similarly, if the valve spool due to some malfunction is seized in the valve body and cannot be moved to the right therein by the normal operating force, the control rod will be moved to the right from the position illustrated in F IG. 1 to the position illustrated in FIG. 2, relative to the valve spool against the force being exerted by the fluid pressure on the outer end of theother piston 172.

When the control rod is moved to the right, as illustrated in FIG. 2, relative to the valve spool, fluid under pressure from the external annular recess23l of the control rod is introduced to the left end of thecylindrical bore 240 of the valve body of the deactivating valve assembly DVA to cause apiston 241 slidable in thebore 240 to move from its non-actuated position, illustrated in FIG. 1, to its actuated position, illustrated in FIGS. 2 and 3, through a passage or conduit means which includes anexternal conduit 244, one end of which is connected to thehousing 25, as at 245 and opens at the inner end of the bore 246 of the housing in which is disposed thevalve body 150 and whose other end is connected to thehousing 25 and opens to an intemalannular groove 248 of the housing, an externalannular groove 249 of thevalve body 40, a passage 250 of the valve body which opens to thegroove 249, aport 251 which opens to the passage, an external annular recess 254 of the valve spool to which theport 251 opens, and ports 255 which open directly to therecesses 254 and 231 when the control rod is in the position illustrated in FIG. 2. The ports 255 are closed by the sealing surface 256 of the control rod when the control rod is in the positions relative to the valve spool illustrated in FIGS. 1 and 3.

When fluid pressure is transmitted to the left end of thebore 240 of the deactivating valve assembly DVA, thepiston 241 is moved to the right to its activated position against the resistance of aspring 260, one of whose ends bears against the annular surface of anexternal flange 261 of the piston and whose other end bears against an annular stop shoulder 264 of a cap 266 whoseenlarged end portion 267 is threaded in theenlarged portion 268 of the bore of thevalve body 150. Thepiston flange 261 and anextension 269 of the piston are disposed in a cavity or chamber 271 of the cap 265. The chamber 271 is in communication with the fluid return passage R2 by means of a slot 274 which opens at its outer end to the chamber and at its inner end to aport 275 of the housing which in turn opens to thehousing recess 56.

It will thus be apparent that as the piston is moved to the right from the position illustrated in FIG. I to the position illustrated in FIGS. 2 and 3, any hydraulic fluid present in the chamber and displaced by the movement of the piston may flow outwardly to the fluid return passage R2 and thus to the fluid return or withdrawal line 54 of the hydraulic system of the aircraft.

When the control rod is moved to the left relative to thespool valve 39, FIG. 3, theexternal recess 231 of the control rod is placed in communication with thehousing groove 248 throughports 283, which are closed by theseal surface 284 of the control rod when the control rod is in its normal operative position relative to the valve spool illustrated in FIG 1, the external annular recess 285 of the valve spool to which theports 283 open, aport 286 which opens to the recess 285, and therecess 249 of thevalve body 40.

It will thus be apparent that if the control rod is moved either to the left or to the right from its normal operating position illustrated in FIG. 1, the pressure of the hydraulic fluid from thepressure inlet conduit 72 of the aircraft hydraulic system is transmitted to the left end of thebore 240 of thevalve body 150 and moves thepiston 241 from its non-actuated position illustrated in FIG. 1 to its actuated position illustrated in FIGS. 2 and 3.

Thepiston 241 has an intermediateannular recess 291 between its external seal surfaces 293 and 294 which sealingly engage the internal surface of thevalve body 150 defining itsbore 240. Theseal surface 293 is always disposed to the left of ports 296 of the valve body which open to theexternal recess 148 and theseal surface 294 closes ports 297 of thevalve body 150 when the piston is in its normal non-actuated position illustrated in FIG. 1.

It will be apparent that when the piston is moved to the right to its actuated position illustrated in FIGS. 2 and 3, fluid communication is established between opposite ends of the cylinder 14 since the ports 296 and 297 are placed in communication through the cylindrical passage provided by theexternal recess 291 of the piston and the internal surface of the valve body defining itsbore 240.

Theextension 269 of the piston rod extends slidably through a longitudinal passage 30] of the cap 265 of the deactivating valve assembly DVA. Abolt 302 rigidly secures the housing of a normallyopen switch 303 in the outer end of thepassage 301. Theactuator button 304 of the switch is engageable by theouter end surface 305 of the piston extension when the piston moves to the right to the position illustrated in FIGS. 2 and 3 to cause closure of the switch. The switch by means ofconductors 306, 307 and 308 connects asignal lamp 309, which may be located on the control panel of the aircraft, in series with a source of current, such as thebattery 310, to give a visual signal or indication to the pilot of the aircraft that the particular control valve assembly CVA is inoperative, as will be explained in greater detail below.

Thevalve body 150 is also provided with arestricted orifice 312 which opens to an external annular recess or groove 314 of thevalve body 150 which is in communication with theannular groove 64 of the housing. The restrictedorifice 312 allows the hydraulic fluid displaced from the left hand end of thebore 240 of thevalve body 150 as thepiston 241 moves from its actuated position, illustrated in FIGS. 2 and 3, to its non-actuated position, illustrated in FIG. I, to flow to the fluid return passage R1.

A dome shapedcover 311 is press fitted on the reduced portion 311a of the cap 265 and protects the outer end of the cap and the switch. Theconductors 306 and 308 are of course led out of the cover through a suitable opening of the cover 31 l.

Hydraulic fluid which may leak into thechamber 26 is returned to the pressure return fluid return conduit 54 by any suitable means such as aconduit 317 connected to thehousing 25 and the return conduit 54. For the same purpose, thechamber 319 of the housing defined by acap 320 threaded in the outer end of the housing bore in which thevalve body 40 is disposed and is in communication with the pressure return duct 54 through aduct 322 connected to the housing which opens to thechamber 319 inwardly of theclosure 320.

Suitable seal means, not all of which are shown in the somewhat schematic drawings, are provided between the various operative elements of thehydraulic control device 10 at required locations. For example, O-rings may be disposed in suitable external recesses of the threevalve bodies 39, 78 and 150 for sealing between the valve bodies and the housing at opposite sides of the external recesses of the valve bodies. Thelands 161 and 166 and the opposite end surfaces 330 and 331 of thevalve body 39 provide a metal to metal seal with the internal surfaces of thevalve spool 40 which they engage.

The sealing surfaces of the pistons and 241 also provide a metal to metal seal with thevalve bodies 78 and 150, respectively.

Assuming now that the hydraulic pressure system of the aircraft is continuously supplying an incompressible hydraulic fluid under a predetermined pressure to the hydraulic fluid inlet or pressure line orconduit 72 and that the hydraulic fluid return conduit 54a is connected to the return inlet of such hydraulic pressure system, the bypass valve assembly BV piston '75 is held in its actuated position illustrated in FIG. 1 by the force exerted by the pressure of the hydraulic fluid on the area on the left hand end surface of thepiston 75 against the resistance of thespring 76. The hydraulic fluid in therecess 101 of thepiston 75 does not tend to move the piston in either direction since it exerts equal or balanced oppositely acting forces on the facing surfaces of equal area defining opposite ends of therecess 101. In this actuated position thepiston 75 of the bypass valve assembly BV provides communication between theinlet conduit 72 and the pressure passage P. The pressure of the hydraulic fluid is communicated through the various passages, ports and annular recesses of the elements of the control valve assembly CVA as described above to thechamber 190 in which the tubular piston 171 is movable so that the pressure of the hydraulic fluid exerted on the annular piston 171 will tend to cause the annular piston 171 to move thevalve spool 39 to the right with thecontrol rod 33 as thecontrol rod 33 is moved to the right and also to thechamber 220 in which thetubular piston 172 is movable so that the pressure of the hydraulic fluid exerted on theannular piston 172 will tend to cause thevalve spool 39 to move to the left with thecontrol rod 33 when thecontrol rod 33 is moved to the left.

Assuming further that the control valve assembly CVA is now in proper operational condition and in the position illustrated in FIG. 1, the pressure of the hydraulic fluid is now not communicated to the left hand end of thebore 240 of thevalve body 150 of the deactivating valve assembly DVA since theports 255 and 286 of the valve spool are now closed. The various passages of the chambers are of course filled with the hydraulic fluid. Hydraulic fluid is now present in the cylinder 14 on both sides of the piston 15 of the motor device 1 1 and hydraulic fluid cannot flow either into or out of the opposite ends of the cylinder since thelands 161 and 166 of the valve spool now close theports 160 and 165, and thus the control fluid passages C1 and C2. As a result, the piston is now held against movement in either direction in the cylinder 14, and the controlledmember 12 is held against movement by the piston, since the hydraulic fluid is of course incompressible. Each of the other motor devices 11 each of the otherhydraulic control devices 10, 10 a ln which control the operation of the other motor devices 11, 11a 11n for moving the controlledmember 12 have control shafts which are linked to thecontrol shaft 28 of the control device and to one another or a singlecommon control shaft 28 operates allcontrol devices 10,10a 10a so that thecontrol rods 33 of the control valve assemblies will be operated simultaneously by the autopilot or by the pilot himself utilizing the usual autopilot override linkage.

If it is determined either by the autopilot or the pilot that the controlledmember 12 should be pivoted in a clockwise manner about the axis of theshaft 19, as thecontrol shaft 28 is rotated in a counter-clockwise manner, the control rod is moved to the right and the force of the pressure fluid exerted on the outer end of the annular piston 171 causes the valve spool to move to the right with the control rod, as to the broken line position thereof indicated in broken lines in FIG. 2, to place the pressure passage P in communication with the control passage C2 through theports 165 which now open to the recess 70 of the valve spool, hydraulic fluid under pressure will now flow from theinlet conduit 72 to the right end of the cylinder 14 through theconduit 155.

The pressure of the hydraulic fluid from the pressure inlet conduit communicated to the control fluid passage C2 and thus to the ports 297 of the valve body does not tend to cause movement of thepiston 241 in either direction since these ports are now open only to thecircumferential seal surface 294 of the piston.

Simultaneously, such longitudinal movement of the valve spool to the right places the return fluid passage R1 in communication with the control passage Cl as therecess 53 of the valve spool moves into alignment with theports 160. As a result the piston will be moved to the left as hydraulic fluid flows into the right end of the cylinder 14 through the conduit and flows out of the left end of the cylinder through theconduit 151. As the control member pivots in a clockwise manner about the axis of theshaft 19 and approaches the desired position, thecontrol shaft 28 is rotated in a clockwise direction and thecontrol rod 33 and thevalve spool 39 move back to the left to the intermediate position illustrated in FIG. 1, the force of the fluid pressure in thechamber 220 causing thetubular piston 172 to move the valve spool with the control rod. Once the valve spool is again in the intermediate position, hydraulic fluid can neither enter into nor exit from either end of the cylinder 14 and therefore thecontrol member 12 will be held locked in the new position.

Conversely, if it is desired that thecontrol member 12 be moved in a counter-clockwise manner about the axis of itsshaft 19, thecontrol shaft 28 will be rotated in a clockwise direction, as illustrated in FIG. 3, and thecontrol rod 33 and thevalve spool 39 will move to the left, the valve spool assuming a position such as that indicated by the broken lines in FIG. 3. As a result, therecess 52 moves into communication with theports 165 so that the fluid from the right end of the cylinder 14 may flow through the fluid return passage R1 and the various passages described above to the exhaust conduit 54a and simultaneously the recess 70 of the valve spool moves into the communication or alignment with the ports so that fluid under pressure from the pressure passage P will flow into the left hand end of the cylinder 14. As a result, the piston will be moved to the right in the cylinder and thecontrol member 12 will rotate in a counter-clockwise direction about the axis of itsshaft 19. The high pressure hydraulic fluid which is now present in therecess 291 of thepiston 241 will not tend to move thepiston 241 in either direction since its force is exerted on equal opposite facing areas of the piston defining the opposite ends of itsannular recess 291. As the control member reaches its desired position, thecontrol shaft 28 is again moved to position thecontrol rod 27 and thevalve spool 39 in the position illustrated in FIG. 1 and the controlledmember 12 will then be locked in such position by the hydraulic fluid in the opposite ends of the cylinder 14.

Should thevalve spool 39 of the control valve assembly CVA, due to some malfunction as for example, the presence of a particles of foreign matter between the engaging surfaces of thevalve spool 39 and thevalve body 40 be held against longitudinal movement in the valve body with a force greater than that exerted by the fluid pressure on the outer ends of thetubular piston 171 and 172, when thecontrol shaft 28 is rotated in one direction or the other, the control rod will move relative to the valve spool. If, as illustrated in FIG. 2, the control shaft 'is rotated in a counterclockwise direction and the valve spool cannot be moved by the force of the hydraulic fluid pressure exerted on its outer annular end surface, the control rod will move to the right relative to the valve spool, therecess 231 of the control rod will move into alignment with the ports 255 of the valve spool and the pressure hydraulic fluid will be communicated to the left end of thebore 240 of the deactivating valve assembly DVA, as explained above, and itspiston 241 will be moved to its actuated position illustrated in FIG. 2. As thepiston 2% moves to its actuated position against the force exerted by thespring 260, itsextension 269 will engage thepush button 304 of theswitch 303 and will cause energization of thesignal lamp 309 which will then indicate to the pilot that the control valve assembly is inoperative and that, as will be explained below, the motor device 11 which it controls has also been rendered inoperative.

As thepiston 241 moves to its actuated position, itsouter recess 291 moves into communication with the ports 297. As a result, a bypass passage between opposite ends of the cylinder 14 is established through theconduit 151, the alignedrecesses 147 and 148 of thevalve body 150 and the housing 250, respectively, the ports 296, the cylindrical passage defined by theexternal recess 291 of thepiston 241 and thebore 240 of the piston, the ports 297, the alignedrecesses 154 and 156 of the housing and thevalve body 150, respectively, and theconduit 155. As a result, the piston of the motor device 11 will now be free to move in the cylinder in either longitudinal direction as thecontrol member 12 is pivoted about the axis of theshaft 19 by the other motor devices.

Since theorifice 312 is of very relatively small dimensions, it will allow a hydraulic fluid under pressure to continuously flow therethrough at a low rate to the fluid return passage R1 but provides enough of a restriction that a pressure in thebore 240 will remain high enough value that the piston will be held in its actuated position thereby against the resistance of thespring 260 as long as therecess 231 is in communication with the ports 255.

Should the force with which thevalve spool 39 is held against movement to the right in itsvalve body 40 decrease below that of the force of the fluid pressure on the piston 171 the force of the fluid under pressure exerted on the tubular piston 171 will of course move it back to the right in the valve body. In that case, as thecontrol rod recess 231 moves out of communication with the valve spool ports 255, the left end of thebore 240 will be placed out of communication with the pressurehydraulic inlet conduit 72 and the force exerted by thespring 260 will be effective to move the piston back to its non-actuated position illustrated in FIG. 1, the hydraulic fluid trapped to the left of the piston in thebore 240 flowing outwardly through the restrictedorifice passage 312 back to the fluid return passage R1.

Conversely, as illustrated in FIG. 3, if for one reason or another the force resisting the movement of the valve spool to the left in thevalve body 40 exceeds the force exerted by thetubular piston 172 on the valve spool, as thecontrol shaft 28 is rotated in a clockwise manner and moves thecontrol rod 33 to the left, the valve spool will remain stationary in the valve body and thecontrol rod recess 231 will move into communication with theports 283, the pressure of the hydraulic fluid from theinlet conduit 72 is communicated to the left end of thebore 240 of thevalve body 150. As explained above, thepiston 241 is moved into its actuated position, the piston 15 of the motor device 11 is freed to move in either direction in the cylinder 14, and operation of the controlledmember 12 by the other motor devices lla-lln n will not be hindered or impeded by the motor device 1 l.

Theannular recesses 231, 254 and 285 of thevalve spool 39 are of such lengths that should the valve spool be seized or held against movement relative to thevalve body 40 when in either of its extreme right or left positions, indicated in broken lines in FIGS. 2 and 3 of the drawings, if the control rod is moved longitudinally relative to the valve spool while it is in such extreme right or left positions relative to the valve body, hydraulic fluid under pressure will be communicated to the left end of thebore 240 in the same manner as when the control valve spool is in its intermediate position and thepiston 241 of the deactivating valve assembly will be moved to its actuated position.

If the aircraft hydraulic system is rendered inoperative so that fluid under pressure is not transmitted through theinlet conduit 72, the force of thespring 76 will be effective to move the piston of the bypass of valve assembly BV to its inoperative position, illustrated in broken lines in FIG. 1. In this inoperative position, theseal surface 335 of the piston closes theports 116 and opens the ports 126 as the piston recess moves into communication therewith. As a result, the pressure passage P is placed out of communication with thepressure inlet conduit 72 and the control passages C1 and C2 are placed in communication with one another through the cylindrical passage provided by the annularexternal recess 125 of thepiston 75 and theinternal bore 106 of the valve body 78 and a bypass passage path for hydraulic fluid is provided between opposite ends of the cylinder 14. Thecontrol member 12 will be free to move since thepiston 16 of the motor device can now move in either direction since the hydraulic fluid being free to circulate between opposite ends of the cylinder as the piston is moved therein.

It will now be seen that a new and improvedhydraulic control device 10 has been illustrated and described which is used to control the operation of a hydraulic reversible motor device, such as the motor device 11, which operates in one direction when hydraulic fluid under pressure is transmitted to a first fluid passage thereof and allowed to exhaust from a second fluid passage thereof, operates in an opposite direction when the fluid under pressure is transmitted to its second passage and allowed to exhaust from its first passage, and is held against operation when flow of fluids to or from both passages is prevented.

It will further be seen that thecontrol device 10 includes a control valve assembly 'CVA having a valve member orspool 39 movable longitudinally in a body means, such as that formed by thehousing 25 and thevalve body 40, the valve member and the body means cooperating selectively to pennit flow of hydraulic fluid under pressure to one of the first and second passages and permitting the exhaust from hydraulic fluid from the other of the first and second passages and permitting the exhaust from hydraulic fluid from the other of the first and second passages when the valve member is in opposite extreme longitudinal positions, and preventing the flow of fluids through the passages in either direction when the valve member is in intermediate position relative to the body means.

It will further be seen that the valve member is movable in the body means by a control means, such as thecontrol rod 33 and thetubular pistons 171 and 172 which are operatively associated with the valve member, the tubular piston exerting oppositely directed forces on the valve member whose values are predetermined by the pressure of the hydraulic fluid and the areas of the surfaces of the tubular pistons exposed to the fluid pressure, on the valve member tending to cause the valve member to move with the control rod.

It will further be seen that the control device includes a deactivating valve assembly DVA, actuated upon the occurence of relative movement between the control rod and the valve member, which occurs when the longitudinal movement of the valve member is resisted by a force greater than the forces exerted thereon by either of the tubular pistons, for providing a bypass fluid passage or path for hydraulic fluid between the two passages of the motor device.

It will further be seen that a new and improved apparatus for operating a control member, such as an aileron l2, spoiler or the like, of an aircraft has been illustrated and described which has a plurality of simultaneously operable motor devices, such as the motor devices 11, 11a lln whose operation is individually controlled byseparate control devices 10, 10a l0n, respectively, and that each control device has means for de-activating the motor device 11 controlled thereby in the event of malfunction of the control device so that the operation of thecontrol member 12 by the other motor devices, whosecontrol devices 10 are still functioning properly, will not be impeded or hindered by the motor devie whose control device is inoperable or has malfunctioned.

The foregoing description of the invention is explanatory only, and changes in the details of the construction illustrated may be made by those skilled in the art, within the scope of the appended claims, without departing from the spirit of the invention.

What is claimed and desired to be secured by Letters Patent is:

1. A control device for controlling operation of a hydraulic motor device having first and second passage means and operating in one direction when fluid under pressure is allowed to flow to one of the passage means and exhaust from the other and operating in an opposite direction to said one direction when fluid under pressure is allowed to flow to said other passage means and exhaust from said one of the passage means, and being prevented from operating in either direction when fluid flow through both passage means is sum from said inlet means to one of said flow passages of a hydraulic motor device permitting flow of fluid from the mot r device from its other flow pas ige means to sai outlet means, and preventing ow through both of said flow passage means, and a deactivating valve assembly operatively associated with said control valve assembly and said motor device responsive to the malfunction of said control valve assembly for providing a bypass flow passage between said passage means of the motor device upon malfunction of the control valve assembly, said body means having first and second passages in communication with said first and second flow passage means of said motor device, and a valve member movable in said body means for selectively placing said first and second flow passages in communication with said inlet and outlet means and preventing fluid flow between said first and second flow passages; said control valve assembly including a control member operatively associated with and movable relative to said valve member, and piston means operatively associated with said control member and said valve member and biased by hydraulic pressure from said inlet means for exerting a force on said valve member tending to cause said valve member to move with said control member, said control member and said valve member having passage means communicating said inlet means with said deactivating valve assembly upon movement of said control member relative to said valve member to actuate said deactivating valve assembly when the movement of said valve member is resisted by a force greater than the force exerted thereon by said piston means.

2. The control device of claim 1, wherein said valve member comprises a tubular valve spool having a central longitudinal bore therein and said control member includes a rod longitudinally slidable in said bore of said valve spool, said piston means comprising a pair of longitudinally spaced tubular pistons, said pistons and said valve spool and said control member having co-engageable means limiting longitudinal movement of said piston means relative to said control member and said valve spool.

3. The control device ofclaim 2, wherein said co-engageable means pemiit limited longitudinal movement of said pistons relative to said valve spool and said rod.

4. The control device of claim 3, and means responsive to the actuation of said deactivating valve assembly for providing a signal at a location remote from said control device.

5. The control device of claim 1, and means responsive to the actuation of said deactivating valve assembly for providing a signal at a location remote from said control device.

" UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,683,749 Date d ugust 15, 1972 fiven f Fred R Rayl e It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Abstract, line 8 [Pg. 1 ln 9] after "such" insert -as- Column 1, line 6 [Pg. 1, 1n. 24] "05" should be -is-.

Column 3, line 42 [Pg. 5, ln. 7] "17" should be -27-.

Column 7, line 6 [Pg. 11, ln. 14] "or" should be -on-.

Column 8, line 57 [Pg. 14, ln. 20] "position" should be positions- Column 11, line 49 [Pg. 19, ln. 28] "l0al0a" should be -l0a-lOn-Column 12, line 66 [Pg. 22, ln. 5] "piston" should be pistons-. Column 14, line 28 [Pg. 24, 1n. 25] after "bypass" delete "of".

wiww UNITED STATES PATENT OFFICE (/69) CERTIFICATE OE CORRECTION Patent No. 3,683, 749 Dated August 15, 1972 Inventor-(s) Fred R. bayles 1 I It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 4, line 25 [Pg. 6, In. 18] "rt" should be "56";

line 53 [Pg. .7, 1n. "34a" should be 83-. Column 6 line 21 [Pg. 10, ln. 1] "164" should be- -l66-;'"=.

line [Pg. 10, ln."5] "FIGURE 4" should be -FIGURE 2 line [Pg. 10, ln. 9] "54'7 Should be 54a-; line 48 [Pg. 10, ln. 2s] "54" should be -54a-. Column 7, line l7 [Pg. 11, ln. 22] after "O-ring" delete "185 and". Column 9, line 14 [Pg. 15, ln. 9 "zoo" should be --2os--.Column 10, line [Pg. l7,'ln. 21] "54" should be --54a--; line 36 [Pg. 17,. ln. 23] "54" should be 54a--; line 41 [Pg. 17, 111. 2d] "54" should be -54a'-.

Column 12, line 53 [Pg. 21, ln. 27] "27" should be --33. Column 13, line 26 [Pg. 22, ln. 28] "250" should be --25--. Column 14, line 43 [Pg. 25, ln. 5] "16" should be --15--.

Signed and sealed this 23rd day of January 1973..

:SEAL) lttest:

EDWARD M.PLETCH'ER,JR. ROBERT GOTTSCHALK Ittesting Officer Commissioner of Patents

Claims (5)

1. A control device for controlling operation of a hydraulic motor deVice having first and second passage means and operating in one direction when fluid under pressure is allowed to flow to one of the passage means and exhaust from the other and operating in an opposite direction to said one direction when fluid under pressure is allowed to flow to said other passage means and exhaust from said one of the passage means, and being prevented from operating in either direction when fluid flow through both passage means is prevented, said control device including: body means having inlet means connectible to a source of fluid under pressure and fluid outlet means; a control valve assembly for selectively transmitting fluid under pressure from said inlet means to one of said flow passages of a hydraulic motor device permitting flow of fluid from the motor device from its other flow passage means to said outlet means, and preventing flow through both of said flow passage means, and a deactivating valve assembly operatively associated with said control valve assembly and said motor device responsive to the malfunction of said control valve assembly for providing a bypass flow passage between said passage means of the motor device upon malfunction of the control valve assembly, said body means having first and second passages in communication with said first and second flow passage means of said motor device, and a valve member movable in said body means for selectively placing said first and second flow passages in communication with said inlet and outlet means and preventing fluid flow between said first and second flow passages; said control valve assembly including a control member operatively associated with and movable relative to said valve member, and piston means operatively associated with said control member and said valve member and biased by hydraulic pressure from said inlet means for exerting a force on said valve member tending to cause said valve member to move with said control member, said control member and said valve member having passage means communicating said inlet means with said deactivating valve assembly upon movement of said control member relative to said valve member to actuate said deactivating valve assembly when the movement of said valve member is resisted by a force greater than the force exerted thereon by said piston means.

2. The control device of claim 1, wherein said valve member comprises a tubular valve spool having a central longitudinal bore therein and said control member includes a rod longitudinally slidable in said bore of said valve spool, said piston means comprising a pair of longitudinally spaced tubular pistons, said pistons and said valve spool and said control member having co-engageable means limiting longitudinal movement of said piston means relative to said control member and said valve spool.

3. The control device of claim 2, wherein said co-engageable means permit limited longitudinal movement of said pistons relative to said valve spool and said rod.

4. The control device of claim 3, and means responsive to the actuation of said deactivating valve assembly for providing a signal at a location remote from said control device.

5. The control device of claim 1, and means responsive to the actuation of said deactivating valve assembly for providing a signal at a location remote from said control device.

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