Nov. 26, 1946. c. A. NEL'soN 2,41 1,747 CONTROL DEVICE Filed Aug. 31, 1944 ___ _ _ INVENTOR l » 'ClaudeANelsm BY Qfz’ ATTORNEY ' Prasad Nome, . 2,411,141 ` ‘ UNITED STATES'I PATENT OFFICE Claude A. Nelson, Wilmerdinß'Pa., assigner to The Westinghouse Air Brake Company, Wil merding, Pa.,- a corporation of Pennsylvania Application August 31, 1944, Serial No. 552,024 z claims. (01121-41) ' ' 4 opposite the strut head l. At the opposite or right hand side of diaphragm 5, as viewed in the drawing, is a chamber I3 which is open to atmos This invention _relates to control devices and ,more particularly to fluid pressure controlled and v operated motors. ‘ phere through a port I4 and winch contains a One object of the invention _is the provision of _an improved motor of the above type. Fluid motors employed on airplanes for ad-v justing various devices such as engine throttles, follower- I5 engaging the adjacent‘face of said diaphragm. The strut heads 8 and 8 and oppo sitely arranged followers AI2 and I5 are secured to the respective diaphragms by any suitable mixture control devices etc. must be as small, compact and light in weight as possible, and -means or in any suitable manner, not shown drawing. ‘ another object of the invention is the provision 10 in Athe bore is provided centrally through the strut of an improved fluid motor embodying these head 8, follower I2 and the interposed portion characteristics and therefore particularly adapt of diaphragm 4, and slidably mounted in this bore is a fluted stem I8. A fluid pressure supply valve Il disposed in chamber I8 >is provided on prises a power member which.A may be in the one end of the stem I6, while on the opposite end form of a piston and which is adapted to be oper-` of said stem, which terminates I'in chamber 8, ated by fluid under pressure to effect .adjustment there is provided a fluid pressure release valve I8. of the device to which it may be operatively con The follower I2 has a seat for engagement by nected, and a pilot portion arranged for control the supply valve I1, while a seat for the release by fluid under pressure to control the pressure 20 valve I8 is provided on an arm I9, the seat ex of fluid on the powe'r‘piston, and according to ~’ tending around one end of a bore 20 in said arm. another feature of the invention a single pipe is 'I'he arm I8 is an integral part of the casing employed for controlling the pilot portion of the section 2 and extends into the space between the motor and for supplying fluid under pressure to strut heads 8 and 8. The opposite end of the motor for actuating the power piston, thereby 25 two bore 20 opens to a chamber 2| in arm I8 and maintaining at a minimum the weight of the said chamber is connected by a passage 22 to 9;/ system for controlling the motor. ' fluid release pipe 23. f Other objects and advantages will be appar The fluid release pipe 23 may lead-directly izoent from the following more detailed description 50 atmosphere, or it may be 'connected to' a sump of the invention. reservoir (not shown) employed for receiving In the accompanying drawing, the single figure fluid under pressure after it has been used to is a longitudinal sectional view of a fluid motor ' ed, though not limited, for such use. The fluid motor embodying the invention com-- V embodying the invention. Description The improved fluid motor comprises a casing produce a desired operation. Fluid'under pres- v sure thus released to the sump reservoir will then - 5 be recompres‘sed into a storage reservoir for use again. Particularly on large airplanes where many fluid motors will be used for controlling different devices, pressure of fluid in the sump l made up of sections' I, 2, >and 3 which are adapted to be rigidly secured together inthe relationship 4 in which they are sho'wn i'n the drawing.` A flex ' reservoir may vary from. for instance, atmos 40 pheric pressure when no fluid pressureis being released to the reservoir, to, momentarily, a‘rela ible diaphragm 4 is clamped around its edge be tween the casing sections I and 2, while a flex ible diaphragm 5 is clamped around its edge be tween the casing sections 2 land 3, said dia tively high degree, such as thirty-five pounds,- if fluid under pressure is released to said reservoir from al1 of the controlling motors at the same phragms being of the same areas and arranged l ' 45 time. in coaxial relation. . In the present application it is merely de sired to bring out however that, in practice, the pressure of fluid in pipe 28 and thus in chamber- Between the two diaphragms 4 and 5 is a cham ber 6 containing a strut ‘I having at one end a 2l acting on the seating side of the release valve head 8 engaging the adjacent face of diaphragm I8 may be of any degree between atmospheric and _ a certain higher pressure, suchy as thirty-'five 50 At 4, and having at the opposite end a head 9 en gaging the adjacent face of diaphragm 5. the opposite side of diaphragm 4 is a~ control chamber I0 connected through a passage >Ilia to pounds, as Just described. Nol further descrip a combined, or common control and fluid pres- ., sure supply pipe I I. Chamber I0 contains a fol lower` I2 engaging the adjacent face of diaphragm tion of the sump reservoir or its function is es ' sential in the present application, although if de sired, reference may be made to the copending 55 application of Rankin J. Bush, Serial No. 480,161, 2,411,747 3 , 4 ñled March 23, 1943, and assigned to the assignee , pipe will preferablybe in excess of atmospheric pressure, for example it may be iifty pounds. of the present application, which discloses a con trol system embodying a sump reservoir, such as above referred to. The spring 40 is interposed between the dia-- phragm follower YI5 and power piston 29 under A bore is provided through the casing section I in coaxial relation to the supply valve I1, and secured to saidcasing section over the outer end such adegree of pressure that, with the `piston 29 in a. normal position deñned by contact with a . stop 42 in casing section 3, the pressure of said spring on the diaphragm follower I5 will hold the ed in this >bore is a sleeve 25 extending into con diaphragms 4 and 5 against the opposing con trol chamber I0 and having a closed end which 10 trol pipe pressure (50 pounds) in chamber I0 in engages the supply valve I1. A coil springv 2B a position in which the supply valve I1 will be of said bore is a, hollow cap 24. Slidably mount- Y -mounted .in sleeve 25 and having one end bearing seated and the release valve I8 will also be seated ‘ againstl the closed end of said sleeve, extends into or slightly open. » cap .24. The opposite end of spring 26 bears The spring 40 is connected to the powerpiston against cap 24. 'I‘his spring is under pressure 15 29 to renderl said piston effective to control, Ü and acts on the supply valve I1 with only suffl- ‘ through said spring, certain operation of the cient force to ensure seating of said valve against diaphragms 4 and 5 and valves'll and I8, as will the follower plate I2 or seating of the release be l"later described, but it will be noted that said valve I8 against its seat.A f spring is .also effective _to urge piston 29 in the Within the cap 24, the sleeve 25 is provided direction of stop 42. The spring 39,15 confined with an annular collar 21 for contact with the under pressure between the shelf 4I -and piston . casing section I when said ycasing section is re 29 and its sole function is to urge the piston 29 moved from the section 2, so- as to hold the spring into contact with stop 42 >upon reducing pressure 26 and sleeve 25 assembled within the casing of iiuid in chamber „30, as will be later described. section I, under such a condition. 25 It will be understood that the spring 39 is re -The casing section 3 has- a bore 28-formed in quired to coact with spring 40 to move piston 29 coaxial relation with the diaphragms 4 and 5 and in the direction of and into contact with stop 42 containing a power movable abutment which may only _in case the resistance to such movement be in the form of a piston 29. The chamber I3 exceeds the pressure of spring 43, as may bethe is provided at one side'of piston 29 whereby said 30 case where piston 29 is of relatively large area, piston is constantly subject on this one side to l or where a Arelatively great force> is required t0 atmospheric pressure. At the opposite side of operate lever 35 and the device which may be piston 29 is a power or operating pressure cham connected to said lever. If the force opposing ber 30 which is -in constant communication movement of piston 29 in the direction of stop through passage 3I with chamber 6 formed be tween the two diaphragms 4 and 5. 35 42 were suiiiciently great, the pressure of spring Y The piston 29 has a stem 32 extending through chamber 30 and a bore in the casing section 3 40 on said piston might be of negligible value in obtaining such movement. However, if the force opposing movement pf piston 29 in the direction to the exterior thereof. A resilient ring 33 car of and into contact with stop 42 does not ex ried in an annular groove in casing section 3 has 40 ceed the forceof spring 40, then the spring 39 sealing and sliding contact with the portion of ' might be dispensed with. the piston stem within the bore in said casing Thearea of' piston 29 'is such as to render it section to prevent leakage of ñuid under pressure effective to rock lever 35 to operate the con from chamber 3l) around said stem to atmos nected device (not shown) against the opposing pressure of spring,40 or of both springs 39 and The outer end of the piston stem 32 is con 40 by a lower pressure vof iiuid in chamber 30 nected by a pin 34 to a lever 35 at a point between Y than is required inchamber I0 on diaphragm the ends of said lever. One end of lever 35 is 4 to move said diaphragm. the str_ut 1 and dia-v connected by a pin 36 to a fulcrum link 31 phragm’5 against spring 40. The diameter of mounted t6 turnon a pin 31a carried in the 50 piston 29 willr therefore depend upon the load casing section 3. In the opposite end of lever 35 which it is required to operate and may be even is a hole 39 for receiving a pin (not shownyto greater than shown in the drawing. . connect said lever, and thereby the power piston Operation 29, to a device which it is desired to operate. phere. - Y _ In chamber I3 are two concentrically arranged coil springs 39 and 40 both _of which bear at one end against the piston 29. The opposite end of spring 39 is supported on a shelf 4I >projecting from casing section 3 into chamber I3. The opposite end of spring 49, which may be called 60 a regulating spring, bears against the diaphragm As above mentioned, pipe I I constitutes a com bined control and nuid pressure supply pipe, that is to say constitutes a control pipe for controlling operation of> the `diaphragms 4 and 5 and thereby` the supply valve I1 and release valve I3, which parts constitute a pilot portion ofthe motor, and Let it' initially be assumed that the control pipe II and control chamber I0 are~ charged with ' fluid at the minimum pressure of fifty pounds above mentioned. Under this condition, the parts of the motor will assume the positions in which «. they are shown in the drawing, as will -be appar- ' ent from the foregoing description. If the pressure of iiùid in pipe II and in cham ber _III is now increased, this increased pressurev effective on diaphram 4 will overcome the oppos ing force of control spring 40 and move the dia phragms 4, 5 and strut '1, and followers I2 and I5 and the adjacent end of said spring> in unison „against the opposing force of said spring and rel also constitutes a iluid pressure supply pipe, or ative to the opposite end of said spring `rand pis a source of fluid under pressure, from which ñuid 70 ton 29. If the release valve I8 is not seated when under pressure is obtained for controlling op the pressure in chamber I 0 is at thenormal de' eration of the power piston 29, in a manner which will be later described. Due to pipe II constitut gree, the initial deflection of the diaphragms will permit seating of said valve under the action of ing a source of ñuid under pressure as just men spring 25. With the release valve I8 seated, how tioned, the normal or minimum pressure in said 75 ever, said valve will hold the supply »valve I1 ' 9,411,741 5 . chamber vI 9. as against movement with the diaphragms, so upon further dcilection of the diaphragme the seat for said supply valve on follower I2 will be moved away from the supply valve. ' scription. - ` Upon opening of _the supply valve Il as :lust de scribed, fluid under pressure supplied to chamber be _evident from the above de - _ „ - 'In the operation lust described, the piston 29, due to thefaction of spring 49, may or may not move in unison with the'diaphragms 4, 9 as they? .i ' _' are operated to openïthe supplyy valve I1, depend ing upon the resistance to movement of the de I9 from the control pipe II, which pipe consti vice (not shown) which is operated by lever Il. tutes a supply source of iluid under pressure, will If this resistance is sufilciently great the piston then flow past the supply valve to chamber 9 and 10 29 may remain stationary when the diaphragms thence through passage 3| to chamber 39. -`When the pressure of fluid supplied to cham- ' _ 4, 9 operate to open the supply valve Il, but if ‘ sufllciently small, said 'piston may move with said _ diaphragm to open the supply valve. If the pis to a degree sufficient-to overcomespring 49 or of, both springs 99 and 49, as the case may be, and ¿'ton 29 does‘not move with the diaphragms 4, 5 A to open the supply valve I1, it will-be immaterial to also actuate lever 35 to operate the device be however, _since- as little. as one one-thousandth ' ing controlled, said piston will move against the opposing force of said spring or springs, and such Y» of an -inch movement will open said valve to sup-v ber 39, and acting on piston 29 is then increased movement will act to increase the force of spring 49 opposing the pressure of fluid in chamber I9 ply fluid under-*pressure to chamber 39'tostop A such movement of said piston. Moreover, this 20 small amount of movement of piston 29 would. on diaphragm 4. ' . ' have substantially no eiîect upon the >device con-. -Now assuming that the increase in pressure of nected to lever 3S, and said piston will be prompt- ' . fluid in chamber I9, eñ‘ective on diaphragm 4, is ly operated by the ñuid under pressure supplied ' limited to some degree lower than maximum pres to chamber 39 to the position corresponding to sure, then when the pressure of spring 49 is in creased, by movement oi? piston 29, to'a degree 25 the increase in pressure in chamber. I9, as above described.sufllcient to overcome the opposing force of said It will now be seen that the piston 29 can bev pressure of ñuid 'in chamber I9, said spring will caused to~ ,move from the normal position, Íin be operated by said piston to move the dia which it is shown in the drawing, to any selected phragms and followers in the direction of the open supply valve I'l and finally move the fol 30 position at the left hand side of normal position vvby providing the proper pressure of fluid in cham-» lower I2 into seating engagement with said valve. ber I9 in excess- of the normal or minimum pres When the supply valve is thus closed, further flow of fluid under pressure will be prevented to cham 'With the piston 29 moved ’awayfrom stop 42, ber 99 and, as a result, movement of the piston 29 will cease. When the piston 29 stops moving, 35 due to the pressure or fluid lin chamber I9 having been increased as above described, let it be as the spring 49 becomes static and movement of the sumed that it is desired to move said piston back diaphragms will also cease ina position in which in the direction of said stop. To accomplish this, the release valve will be still seated, whereby the sure. 1 v . fluid under pressure will be bottled in chamber the pressure of iluid in chamber I9 will be reduced the power piston 29 moves to a position deter mined by and corresponding to the degree of in in the direction of chamber I9. This movement of the diaphragms and thereby of the seatedV sup ply valve I'I will act through the stem I6 to pull the release valve I8 out of contact with its seat, 39 to maintain the piston 29 and~ lever 35 against 40 to destroy the equilibrium between its effect on diaphragm 4 and the opposing pressure of spring movement. ' 49. Spring 49 will then deflect the diaphragms From the above description it will be noted that crease in pressure of fluid in chamber I9 above the normal orminimum pressure, and it; will be further noted that this movement of the power . f whereupon fluid under’pressure will be released piston, while opposed by springs 39 and 49, is de pendent upon a sumcient increase in pressure in chamber _39 to actuate the lever 35 and the device which may be connected to said lever. Thus a relatively low pressure of fluid in chamber 39 may be adequate to operate the piston 29 at one time or under a certain condition, while a higher pres sure of fluid will be required to cause the same movement of said piston at another time or un der a different condition. The area of piston 29 is such however that under all conditions it will from chamber 39-through passage 3i, chamber 6 and past said release valve~to chamber 2| and thence through passage 22 to release pipe 23. The consequent reduction in the pressure of fluid in chamber 39 will then permit movement of' pis ton 29 by spring 49 or springs 39 and 49 in the direction of stop 42, it being noted that such - movement will allow expansion of spring 49 and thus a reduction in the force it exerts againstJ the diaphragms. - Assuming that the pressure of fluid in cham ber I9 is not reduced to its normal degree, then ' be moved against spring 49, by fluid in chamber 39 ‘at a, lower pressure than is present in cham 60 as soon as the pressure of spring 49 becomes re duced, as just described, to a degree which sub- , ber I9, and in pipe i I which constitutes the source of supply of fluid under pressure for operating said piston. - Now let it be assumed that the pressure of fluid l stantially equals the force on diaphragm 4 pro vided by the pressure of fluid in chamber I9,- the diaphragms and valves will be moved in unison in chamber I9 isincreased to a higher degree 65 by pressure of iluid in said chamber and cause the release valve I9 to move toward its seat and than above considered. Upon such an increase finally into contact with its seat in a. position of the diaphragms 4, 5 will again be deflected against piston 29 in which the reduced pressure off spring the opposing force of spring 49 to reopen the sup 49 substantially equals theforce developed by the ply valve Il for supplying more fluid under pres sure to chamber 39. The piston 29 will then 70 reduced pressure of fluid in chamber I9 acting again move against the opposing force of spring , on the diaphragm 4. -When the release valve is 49 or of_ springs 39’and 49 and cause operation thus closed further release of fluid under pressure from chamber 30 will stop and piston 29 willv of the diaphragms _to again close the supply -thenstop moving in a position corresponding to valve'in a new position of said piston, correspond ing again to the increasein pressure fluid 'in 75 the degree of reduction in pressure of fluid in 2,41 1,747: chamber iii, or in other words, corresponding to sure controlled pilot portion for controlling the the pressure in said chamber in excess of_ the'nor mal minimum pressure. In the operation just described, the piston 29 power portion, and a single or common pipe serves> asl a control pipe for the pilot portion and as a fluid pressure supply pipe, or as a source may, or may not, move in unison _with diaphragms 5 'of fiiiid under pressure, for controlling operation 4 and 5 in response to a reduction in pressure of iiuid in chamber i0, depending upon the resist of the power portion. v chamber I0, the motor will again operate, as just sides ofsaid power andpilot means in opposi _ Having now described my invention, what I claim as and desire to secureby letters Patent, is: ance to movement of the device (not shown) con 1. A 'lluid motor comprising a casing, power nected to lever 3_5, as will be obvious from the,A above description of operation of the device in 10. means in said casing subject on. one side to pres» response to an increase in pressure of ñuid in sure of fluid in a power chamber, pilot means in saidcasing arranged in coaxial relation to said chamber i0. Regardless of this, however, the power means and subject on the opposite side to piston 29 will be moved to a position correspond lng to the pressure of i‘luid in chamber I0 upon a , pressure of fluid in a control chamber connected 15 to a iluid pressure supply and control passage. reduction in such pressure, as above described. a coil spring in said casing acting on adjacent Upon a further reduction in pressure of iiuid in tion to pressure of ï iluid in the respective said described, to cause a corresponding change in po chambers, valve means controlled by said pilot sition of piston 29. If the pressure of ñuid -in chamber I0 is reduced to the normal degree, the 20 means for controlling communication between said passage and a third chamber at the opposite e piston 29 will be moved by spring 39 or springs 39 and d0 to its normal position in which it is side of said pilot means,‘means opening said shown in the drawing. Before the release valve - third chamber to said power chamber. said valve means also controlling a communication between I8 seats or it may seat at the instant said pis ton engages stop 42. In either case, a complete v25 said third chamber, and thereby said power chamber, and atmosphere, said pilot means being return of the piston 29 to its normal position will be obtained. ' If as just mentioned the release valve I8 is seated at the time piston 29 contacts stop 42, the pilot diaphragm 4 will be conditioned to operate 30 in said control chamber to effect operation of said valve means to open communication between said to more quickly open the supply valve I1 upon a erable upon -a reduction» of pressure of ñuid in said control vchamber to open said third chamber subsequent increase in pressure in chamber l0, bottle up fluid ir said chamber at a pressure in suiiicient however to move piston 29 out of con 35 third chamber on said pilot means and render ing the adjacent side of ,said power means subject tact with said stop. This bottled pressure how ever will render piston 29 more quickly respon to atmospheric pressure. 2. A ñuid motor comprising a casing, power sive to a subsequent supply o1' iluid under pres valve I1, as will be readily apparent. passage and_said third chamber 'and being op to atmosphere, and lmeans_in said casing counter acting the action of fluid pressure'in the said also, the closing of said valve at this time may sure to said chamber by opening. of thesupply operable upon an increase in pressure of ñuid means in `said casing subject on one side to pres . 40 sure of fluid in a power chamber, pilot means in It will now be seen' that the power piston 29 can be caused to move toward and to be stopped, isaid casing arranged in coaxial relation to said 'power means and subject on the opposite side in any selected position out of its normal «pesi-Y ‘ to pressure of fluid in a control chamber, a coil spring in said casing acting against adjacent tion by reducing the pressure fluid in chamber IUI to the proper selected degree, or the fullvand un’ 45 sides of said power and pilot means in opposi tion to pressure of fluid in the‘respective said interrupted return to normal position may'be ob' chambers, valve means in said casing controlled tained, if desired, by a continuous reduction in by said power and pilot means and operable pressure of fluid inìchamber Il) to'the normal by said pilot means upon an increase in pressure minimum pressure. f of fluid in said control chamber to supply iluid It will be noted that the pressure of ñuid in to a third -chamber at the opposite side of said chamber 39 also acts in chamber `6 at all times pilot means and operable upon a'reduction in but has substantially no influence upon the'above pressure of ñuid in said control chamber to described operation of the pilot portion of the~ motor due to its action on one diaphragm being release ñuid under pressure from said third cham counteracted by its effect on the other diaphragm. 55 ber, means providing a constantly open com munication between said third chamber and said In case pipe 23 is connected to a sump reser _power chamber, said power means being- operable voir, as hereinbefore mentioned, it will be seen either against or by said spring means, to a posi-> that the pressure cf'ffiuid in chamber 30 can tion corresponding to the increase or reduction only be reduced as above described, to the pres in pressure of_ fluid in said control chamber, to. sure effective in said reservoir. The pressure effect operation of said valve means to bottle of springs 39 and 49 is such however as to insure the iiuid pressure in said third and power cham movement of the piston 29 into contact with Istop bers, the pressure of fluid in said third chamber 42 against the maximum pressure which may be being effective on said pilot means in opposition eiïective in the sump reservoir and in chamber 39. 65 to pressure of fluid in said-control chamber, and means operable by pressure of 'iluid in said third It will now be apparent that I have provided chamber to counteract the effect of the pressure a power motor which is relatively simple and com of fluid in said third chamber on said pilot means pact and which may be relatively small and ._ and also rendering the adjacent side oi.' said light in weight, for the purpose intended. The o power means subject to atmospheric pressure. motor comprises a power portion which is op erable by ñuld under pressure, and a iluid pres CLAUDE A. NELSON.