US2401680A - Fluid pressure control mechanism - Google Patents

Description

`June 4, 1946. 'w. A. EATON lFLUID PRESSURE CONTROL MECHANISM Filed 00's. 5, 1943 INVENTOR l Arron/vers Patented June 14 1946 FLUmPnEssURE CONTROL MEcnANIsM vwan-ea A. Eaton, Elyria, oai, assigner u Bendix'Westing'nouse Automotive Air Brake Company, Elyria, Ohio, a corporation o! Dela- Application October 5. 1943, Serial No. 505,068

14 Claims.

This invention relates to fluid pressure centro mechanism and more particularly to mechanism for effecting the control or' a remotely positioned device such as an airplane or boat rudder without the use of mechanical connections between the device to be controlled and the operators control station. f

It has been previously proposed to utilize luid pressure operated mechanism forA remotely con;-

trolling devices of the above character, but difficulty has been experienced in connection with some of these mechanisms in providing a properly graduated control similar to that provided by direct mechanical connections; and it is accordingly an object of the present invention to provide mechanism for overcoming these dii- V culties.

A further object of the yinvention is to provide remote control mechanism of the so-called telemotor type wherein the' mechanism for controlling the energization of the actuator is responsive jointly to the operation of the operators control member and the movement of the device to be actuated.

Yet another object of the invention is to provide, in connection with a system of the above type, simple and eicient means for indicating to the operator the degree of movement of the actuated device.

A still further object of the invention is to provide control mechanism of the above type wherein valve mechanism o1.' the self-lapping type under 2 Referring to the drawing, the invention is illustrated in connection with an airplane elevator or Y rudder I pivotally mounted on the airplane, not shown, .by means of a shaft 5, the elevator being actuated by means of a double acting fluid motor E, having a piston 'I connected with the elevator through the medium of a piston rod 8 and a lever 9. The uid actuator or motor 6 is provided with a cylinder Ill in which the piston is slidably mounted, the piston, and consequently the elevator, being normally maintained in the neutral position shown by means of opposed springs Il and l2 interposed between the piston and the left and right ends of the cylinder, respectively. The left end of the cylinder is pivotally mounted by means of a pin I3 on a bracket I4 carried by the airplane, leakage around the piston rod at the right end of the cylinder being prevented by means of a suitable seal lli.

A source ofiiuid pressure such as al reservoir l5 is provided, fluid pressure being supplied to the reservoir by means of a compressor, not shown, through a conduit I1. The iiow of fluid pressure from the reservoir to the'motor G is controlled by means of an uperators duplex control valve mechanism l 8, nuid pressure being supplied to the valve mechanism through a conduit I9, and being supplied from thel valve. mechanism to the right; and left ends of the motor respec-' tively, through conduits 20 and 2l, the conduits being provided at their right ends with iiexible hose portions 22 and 2l in order to provide for movement of the cylinder I0 about the -pivot pin ing. It is to be expressly understood, however,

that the drawing is employed for the purpose of illustration only and is not designed as a definition of the limits of the invention, reference being had for this purpose to the appended claims.

In the drawing, the single -viewillustrates diagrammatically and partially in section, acontrol mechanism for the elevator of an airplane constructed in accordance with the principles of the present invention.

The valve mechanism I8 is provided with a casing 2l having an inlet chamber 25 connected with the conduit I il.V The left hand portion of the valve mechanism is provided with an outlet chamber 26 separated from the inlet chamber ,by means of a ported partition 21, communica- 30 carried on the upper end of a stem 3| extending upwardly from the intake valve. The upper end of the outlet chamber 28 is closed by means of a partition 32 -formed in the casing, this partition beingprovided with 'a'vertical bore 33 arranged substantlally in alignment with the inlet and exhaust valve assembly. A valve operating element Il is slidably mounted in the bore, leakage from the upper end of the outlet chamber surfaceV of the nut l1. u v

vented by means of a suitable seal 35. The valve operating element is provided with-a centrally located bore 3'6, the lower end of the bore being normally in communication with the outlet chamber and being adapted to close on engagement with the upper surface of the exhaust valve 30 during downward movement of the valve operating element. A pressure responsive member or diaphragm 3l' is clamped between the upper face of the casing 2d and a cover member 3d, the vdiaphragm being attachedat its center to the valve operating element by means of a suitable flanged nut 39, and forming in connection with the casing and the partition d2, a control chamber 3de forv the diaphragm which is utilized for purposes to be more fully described hereinafter. The diaphragm forms in connection with the cover plate, an exhaust chamber d having an atmospheric conduit di, and in view of the fact that the upper end of the bore do is connected at all times with chamber dil, it will be understood that with the valve mechanism in the position shown, the outlet chamber Zwill likewise be connected with atmosphere. In order that the valve operating element may be actuated by the operator to close the exhaust valve and open the intake valve tosupply iiuid pressure to the right end of the motor 8 through the conduit 2d and the hose 22, an operating lever 42 is pivotally mounted on the cover by means of a pivot pin 43, this lever being provided with a cross bar 44, the left end of which is adapted to engage the upper end of a valve operating plunger 45 slidably mounted in the upper vend of the cover as shown. In order that the plunger 45 may serve to actuate the valve operating element in a downward direction to close the exhaust valve and open the intake valve, a resilient connection or spring 46 is interposed between the upper surface of the nut 39 and the lower end oi' the plunger 45, it thus being apparent that on movement of the lever 42 4in a counterclockwise direction, the' plunger 45 will be moved downwardto increase the tension of the graduating spring 46, with a corresponding tendency for the valve operating element and diaphragm to be moved downward to close the exhaust valve and subsequently open the inlet valve to establish communication between the inlet chamber 25 and the outlet cham r 28. As heretofore stated the valve mechan sm il is of the duplex type, and consequently the arrangement just described is substantially duplicated in the .righthand portion oi' the valve, this portion being provided with an' outlet chamber 41, inlet andexhaust valves 48 and 49, a valve operating element 50 provided with a bore li adapted with the element in the position shown to connectthe outlet chamber with an exhaust chamber 52 connected with atmosphere through an exhaust conduit 53, together with a diaphragm I4 and a control chamber formed in the casing below the diaphragm, this chamber being connected with the control chamber ai by means oi.' a port l0 as shown. The diaphragm is attached to the valve operating element 'by means ot a nut l1 and the element is operated by means of the lever 42 and the bar 44 through the medium of 's slidablymountedvvalve operating member Il and a graduating spring Il interposed between "the lower end of the sliding member'sn'd the upper 4 right side of the diaphragm and the left endl The inletl It wuibe readily ondersteunen the :oregoing description that on movement oi' the cont l lever in a countercloc'kwise direction.Y the pl u will be moved downward to compress the graduating spring 48 with resultant downward movement of the diaphragm and valve operating element 34 to first closel the exhaust valve l and subsequently open the intake valve against the tension of the inlet valve spring 29, thus permitting substantially unrestricted' communication between the reservoir I6 and the right end of the motor 8 through conduit i9, inlet chamber 25, ported partition 2l, outlet chamber 26, conduit 20 and flexible hose 22, this application of iluid pressure to the right end of the motor tending to move the piston 'I to the left with consequent clockwise rotation of the elevator 4 about the pivot shaft 5. In the absence of any further mechanism, it is apparent that substantially full reservoir pressure wouldbe supplied to the motor 6, and in order to control the operation of the valve mechanism I 8 and to control the degree of movement of the elevator l in response to a given degree of movement of the mechanism 42, a self-lapping control valve mechanism 60, which may be ofv any well-known type.

butis preferably constructed in accordance with i the principles set forth in the patent to William J. Andres and Roy S. Sanford, No. 21,133,275, dated October 18, 1938i, is provided with an operating plunger 6I adapted for actuation by means of a cam 62 carried by the elevator 4 and the shaft 5. The control valve mechanism is provided with aninlet chamber 63', an outlet chamber 64, a diaphragm chamber connected with the outlet chamber by means of a restricted passage 66, together with an exhaust chamber 61 connected with 'atmosphere by means oi' an atmospheric connection 6l, communication between the inlet and outlet chambers being controlled by an inlet valve 89, and between the outlet chamber and the exhaust chamber by means of an exhaust valve 'i0 and'a; valve operating element 1l having a bore 'i2 serving to normally connect the outlet chamber with the exhaust chamber, the valve operating element being adapted for actuation in one direction by means of a diaphragm 'Il subjected to the pressure in the diaphragm chamber, and in the other direction by means of a graduating spring 14 interposed between the of the valve operating plunger 6|. chamber 63 is connected with the reservoir through a conduit 15 connected with the conduit i9. the outlet chamber being connected with the control lchamber Bl of the valve mechanism il vby means of a, conduit 16, it being noted that control. chamber is in turn connected with the control chamber 39a by means of the port N as heretofore described. In addition to the foregoing, the cam O2 isv preferably so formed as to permit the operating parts of the valve lll to remain substantially in the position shown when the elevator 4 is inneutral position, movement of the elevator, and consequently ol' the cam in either' direction from that position, serving to cause the cam to move the valve operating plunger 8| tothe lett. On reference to the above ber .4l andthe exhaust conduit ",sndon iurther movement to open the inlet valve Il tov permit communication between the inlet chamber and the outlet chamber, the valve mechanism thereafter serving to automatically maintain a pressure in the outlet chamber 64 and consequently in the conduit 16 which is substantially proportional to the degree of movement of the valve operating plunger 6| from the position shown. When the plunger 6I is operated by the cam 62, itV will be understood that the surface of the cam in contact with the plunger can be so proportioned as to vary the pressure delivered by the valve in any desired ratio to the degree of movement of the elevator to either side of neutral position.

Assuming for example, that the operator de-l sires to move the elevator i in a clockwise direction invorder to raise the tail of the airplane and depress the nose, it is only necessary for him to move the control lever 42 inl a counterclockwise direction about the pivot pin 43, whereupon the plunger l is depressedl in accordance with the degree of movement ofthe lever, and the graduating spring 46 is accordingly compressed to a degree proportional to the degree of movement of the lever. When this action occurs, the lower end of the valve operating element 34 will contact the exhaust valve 30 to close off communication between the outlet chamber and the exhaust conduit Il, subsequent movement of the element serving to open the inlet valve 28 to permit communication between the reservoir I6 and the right end of the fluid motor through the connections already described. Thereupon the piston l will be moved to the left, and in view of its connection with the elevator through piston rod l and lever 9, the elevator and the cam 62 will be rotated in a clockwise direction about the 'shaft t. This rotation of the cam 62 will serve to depress the valve operating plunger ti of the valve mechanism 5@ in order to establish a pressure inthe outlet chamber te and in the conduit 'it which is substantially proportional to the degree of movement oi the plunger 6| and consequently to the degree of movement of the cam @it and the elevator il, and since fluid from thel outlet chamber is supplied to the control chambers tta and lit through the conduit lt, as heretoiore described, it will be understoodthat the elevator may eventually reach a position such that the pressure delivered by the valve mechanism titl to the control chamber 39a will exert a sufilcient upward force on' the diaphragm 3l to overcome the force exerted by the spring tt and to move thevalve operating element Bt upward to permit closing of the inlet valve 2t under the action of the inlet valve spring 29. In the event the elevator continues its movement in the cloclrwise direction dueto the inertia ofthe iluid or inertia of the moving parts, it will be clear that the pressure delivered by the valve mechanism tu will still further increase, this increased pressure acting on the diaphragm 3l to move the valve operating element 3d upward suillciently to permit opening of the exhaust valve and consequent escape of the excess fluid pressure from elevator, and a condition oi balance will be evenltually reached wherein the pressure delivered to the motor by the valve mechanism I8 is: maintained at a value just suilicient to maintain the elevator in a position proportional to the degree of movement of Ithe control lever 42, movement of the elevator in either direction from this position by the application of an outside force tending thus to control the valve mechanism 80 to increase or decrease the pressure in the motor 6 in orderi to compensate for the unbalanced condition set up by the application of the outside force. In like manner, movement of the lever l2 in the opposite Vdirection from neutral position will serve to supply pressure to the left end of the motor in order .to rotate the elevator in a counterclockwise direction, whereupon the valve mechanism C0 will again be under the control of the cam $2 to increase the pressure in the conprovide means for advising the operator as tothe actual position occupied by the elevator or other control surface, and simple and eillcient means is the right end of the motor B through, the hose t2, the conduit 2li, rtl'leoutlet chamber 2G, lthe bore tt, the chamber 40 andthe exhaust conduit tl, the operation of the valves '2t and 30 thus being controlled in one direction by means of the graduating spring 4B, and in the other direction by means of the diaphragm Il in response to the pressure applied thereto by operation of the valve mechanism l. this pressure in turn being responsive to the angular movement o! the provided in the present invention for accomplishing this desirable end. As will be understood by those skilled in the art, self-lapping control valves such as the valve mechanism 60 are adapted to deliver an output pressure proportional to the degree `of movement of the operating plunger, and since the operating plunger of the valve is actuated by a cam carried bythe control surface, it will be apparent that the output pressure of the valve and the pressure in the conduit 16 will at all .times be substantially proportional to the degree of movement of the control surface from neutral position, although it is to be understood that the surface of the cam may be varied in order to provide any desired proportion between the delivered pressure and the degree of movement oi the control surface. The 'output' pressure of the valve is accordingly a measure of the angular movement of the control surface, and a pressure gauge ll is accordingly provided which is connected with the conduit i6 by means of a conduit 'it and is therefore responsive at all times to the pressure delivered by the valve mechanism tu. The dial oi the indicator may be graduated to show the actual pressure delivered by the control valve, but is preferably graduated to indicate the angle of turn of the elevator from neutral position, -it being understood that the intervals tween the various graduating points on the gauge dial will vary in accordance with i variations in the shape of the cam 52 `which serves to operate the valve. Thus, on operation of the control lever d2 to eiect movement of the control surface in either direction from neutral position, the pointer of the gauge 11 will indicate the angle oi? turn of the control surface, as weil in the valvefmechanisxn Il are subjected at all annoso' times to the pressure of fluid obtaining in the outlet chambers 28 and 41 respectively, and-are consequentlyl responsive to the pressures existing in the respective ends of the iiuid motor. Thus, operation of the valve operating element 3l, for example, to operate the valves 28 and 30, is opposed not only by the vpressure supplied to the chamber 39a by the operation of the valve mechanism 60, but also by the pressure in the right end of the fluid motor and in the outlet chamber 26 acting on the lower end of the element. While the valve operating elements are connection between said control member and element, power operated means associated with said element for moving the latterin said another direction, and means for supplying power to said power operated means for moving saidelement in said another direction including power control means and means controlled by movement of said device for operating the power control means for 4 correspondingly varying the powerfsupplied to illustrated as having relatively small areas, it will be understood that the areas of these elements may be so proportioned as to provide any desired degree of reaction on the operators control member 42 in order to advise the operator of the degree of energization of the 'motor i. Thus, each portion of the valve mechanism I8 is provided with a member responsive tothe pressure in the fluid motor and a second member responsive to the pressure delivered bythe valve mechanism 60, which in turn is proportional to the angle of turn of the elevator 4 from neutral position, the two pressure responsive members thus providing means for apprising the operator at all times not only of the angle of turn of the device being vactuated but also of the degree of energization of the actuating motor.

While the invention has been illustrated and described as utilized in connection with the operation of one of the movable control surfaces of ari-airplane, it'will be understood that the invention may be utilized for the control of other types of devices requiring graduated remote acl tuation under the control of the operator, While there has been shown and described one form of the invention, it is to be expressly understood that same is not limited thereto but may be ernbodied in various forms. Various changes in the size and shape, as well as inthe arrangement of `the various parts, may likewise be made without departing from the spirit of the invention. Reference will, therefore, be had to the appended claims for a definition of the limits of the invention. l

What is claimed is: l. The combination with a device to be actu- .ated and a iluid motor for operating the device,

of means for controlling the energization of said motor including valve mechanism having a valve operating element movable in one direction to supply il'uid pressure to the motor and in another direction'- to release iiuid pressure from the motor, manually operable means having a resilient connection with the element for moving the latter in said one direction, a pressure responsive ,member associated with the element for moving 4- vice, of means for controlling the energization of said actuator including power controlling mechanism having an element movable in one direction to supply power to the actuator and in another direction to release power from the actuator, a movable control member for operating said element in one direction, a resilient operating said power operated means by the power control means. i

3. The combination with a device to be actuated and a iiuid motor for operating said device, of means for controlling the energization of said motor including valve mechanism having valves operable in one position to supply fluid pressure to the motor and in another position to release fluid pressure therefrom, a valve operating element for moving said valves, means for moving the element to move the valves to said one position including a manually operable member and a resilient connection between said member and element, a pressure responsive member associat g ed with the element for moving the latter to move the valves to the other position, means including a self-lapping valve for supplying fluid pressure to said pressure responsive member, and means for effecting an operating connection between said self-lapping valve and device whereby said valve is operated by movement of the device to vary the pressure of uid supplied to said pressure responsive member in accordance with said movement.

"4. The combination .with a device to be actuated, a iluid motor for operating the device, and a control member for controlling the operation of the device, of means for controlling the degree of energization of said motor in accordance with the degree of movement of said member and device including valve mechanism having inlet and exhaust valves for supplying fluid pressure to the motor and releasing uid pressure therefrom, a valve operating element movable in one direction to close the exhaust valve and open the inlet valve and operable in another direction to permit closing of the inlet valve and to open the exhaust valve, a spring for connecting the control member and element for operating the latter in said one direction, a spring for closing the inlet valve,

a pressure responsive member connected with J the valve operating element, and means for supplying fluid pressure to said pressure responsive member to move the element in said another direction including a control valve operable by movement of the device for varying the pressure of fluid supplied to said pressure responsive member in accordance with said movement.

5. The combination with a device to be'. actu-v -pressure to the motor to operate thev device in either direction, a pair of valve operating elements selectively movable in one direction to operate the valves to control the supply of iluid pres-` sure `to the motor to operate the device in one ating connection between each element and the control member for operating the elements in one said direction, a separate pressure responsive member for moving each element in the other di rection. and means for supplying iluid pressure to said pressure responsive members to move the corresponding elements in said other direction including a control valve and means associated with said control valve and device for 'operating the valve to increase the pressure of iiuidsupplied to said pressure responsive members whenever the device is moved Ifrom neutral position in either direction.

6. The combination with a device to be actuated and a double acting liuid motor for operating the device in either direction from a neutrai position, of means for controlling the supply'of iiuid pressure to the motor including a pair of valve operating elements each operable to supply fluid pressure to kthe motor to operate the latter in one direction or the other and to release fluid pressure therefrom, means for selectively moving said elements to supply fluid pressure to the motor including a control member and resilient connecting means between lthe control member and elements, pressure responsive means for moving said elements to release fluid pressure from the motor, and means including a valve controlled by movement of-said device for varying the pressure of fluid supplied to said pressure responsive means in accordance with the movement of said device in either direction from neutral position.

7. The combinationwith a device to be actuated and a fluid motor for actuating the device, of means for controlling the supply of fluid pressureto said motor including an element operable in one direction to supply rfluid pressure to the motor and in the other direction to release fluid pressure from the motor, means including a movable control member and a resilient connection between the member and element for moving the latter in said one direction, means for subjecting the element to the pressure in the motor for moving the element in said other direction, a pressure responsive member for moving the element.` in said other direction, and means for varying the pressure of fluid supplied to said pressure responsive member in accordance -with the movement of said device including a control valve operated by the device.

' t. The combination with a device to be actuated and a fluid motor for actuating the device, of means including a control member for controlling the supply of fluid pressure to said motor, and

'means for: opposing operation of said control memi ber with a force varying substantially in accord- V ance with the degree of movement of said device including a pressure responsive member, a resil-v lent connection between the pressure responsive member and control member, and means controlled by the movement of the device for subjecting the pressure responslvemember to a correspondinglv varying pressure. l

9. The combination with a device to be actui ated and a iiuid motor for actuating the device.

or the other of said directions, a resilient operconnection between the element and control member, a pressure responsive member connected with the element, and means controlled by the move-l ment of the device for subjecting the pressure responsive member to a correspondingly varying pressure.

`10. The combination with a device to be actuated and a fluid motor for actuating the device, of means including a .control member for controlling the supply of fluid pressure to said motor, means for opposing operation of said control member with a force varying substantially in accordance with the 'degree of movement of said device including a pressure responsive member,

a resilient connection between the pressure responsive member and control member, and means controlled by movement of the device for subjecting the pressure responsive member to a correspondingly varying pressure, and ineans for advising the operator of the degree of movement of said device including an indicator responsive at all times to the pressure to which the pressure responsive member is subjected.

1l. The combination with a device to be actuated, a power actuator for the device, and means including a power controlling element for controlling the supply of power to the actuator, of means for controlling the operation of said element including a control member having a -resllient connection with the element for moving the latter to supply powerto the actuator, a power responsive member for moving the element to release power from the actuator, and power supply means controlled by movement of said device for varying the power supplied to said power responsive member in accordance with the movement of said device.

12. The combination with a device to be actuated, a power actuator for the device, and means including a power control element for controlling the supply of power to the actuator, oi means for controlling the operation of said element including a control member having a resilient connection with the element for moving the latter to supply power to the actuator, and means for mov=` ing the element to release power from the actuator includingmeans for subjecting the elementv to the power supplied to the actuator, a pressure responsive member for moving the element, and

power supply means controlled by movement of I said device for varying the power supplied to said power responsive member in accordance with the movement of said device.

13. Control mechanism for a device of the type having a power actuator for actuating the device, means including a power` controlling element for controlling the supply-of power to the actuator, and means for controlling the operation of Asaid element including a control member having a resilient connection with the element and a power responsive member connected with the element, said mechanism including power supplyI means for varying the supply of power .to said power responsive member and an operative' connection between said device and power supply means for operating the latter to vary the degree of power supplied to said power responsive member in accordance with the movement of said device.

i4. Control mechanism for a device of the'type,

c luding a control member movable in one direcplyinc means having an operative connection tion and having a resilient connection with the with the device and operable to vary the degree element and' a power responsive member conof power supplied to the power responsive memnected with theeiement, and means for controiber in accordance .with the movement of the ling the supply of power to said power responsive 's device. member to move the latter and control member WIIFRED A. EATON. in the opposite direction including power sup-

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