US2439458A - Fluid pressure control mechanism for airplane deicers - Google Patents

Description

w. A. EATON 2143945 FLUID PRESSURE CONTROL MECHANISM FOB.' DEIGERS Filed 30:, 1943 2 Sheets-Sheet l April 13, 1948. w. A. EAToN 2,439,458

FLUID PRESSURE CONTROL MECHANISM FOR AIRPLANE DEICERS Filed April 30, 1943 2 Sheets-'Sheet 2 FEED VALVE.

Patented Apr. 13, i943 FLUID PRESSURE CONTRL MECHANISM FOR AIRPLANE DEICERS Wilfred A. Eaton, Elyria, Ohio,.assignor to Bendix-Westinghouse Automotive Air Brake CompanyElyria, Ohio, .a corporation ofDelaware Application vApril Si), 1943, Serial No. 485,227

9 Claims. 1

This invention relates to control mechanism for airplanes and moreparticularly to uid pressure means for controlling the deicin'g mechanisin of an airplane.

it has previously been proposed to employ iniiatable deicer boots on the wings of airplanes in order to removeice formations dangerous to the operation of the airplanesvbut in many of the systems proposed, it' has been necessary for the pilot to manually control the deicing mechanism, and in some cases the pilot has neglected to set the deicing mechanism in operation in time to prevent ice accumulations suiilcient to interfere with the safe operation of the airplane, and it is accordingly one of the objects of the present invention to' overcome these difculties.

A further object of the invention is to provide means for automatically indicating to the pilot the formation of ice` on the wings of the airplane in suiiicient quantity to interfere-with the safe operation of the airplane.

Yet another object of the invention is to provide means controlled by the'formation or ice at one point on the airplane for automatically inflating or deflating the deicers to remove ice accumulations at another point on the wings of the airplane.

Still another object of theinvention is to provide means for preventing formations of ice on the wings of the airplane fromfinterfering with the operation of the automatic deicer control means.

A further object of the invention is to provide automatic mechanism for controlling theoperation of the deicers, which may be readily applied to deicers ofthe existing type.

These and other objects of the invention will be more readily apparent when taken into consideration with the accompanying drawings, wherein two embodiments of the invention are illustrated. It is to be expressly understood, however, that the drawings are employed for the purpose of illustration only, and are'not designed as a definition of the limits of the invention, reference being had for this purpose to the appended claims.

In the drawings, wherein similar reference numerals are used for similar parts throughout the several views,

Fig. l is illustrative of an. automatic deicer mechanism constructed in accordance with the principles of the present invention;

Fig. 2 is a view in section of. one portion or the system; and

Fig. 3 is a View, partially in section, of another embodiment of the invention.

Referring more particularly to Fig. l, the deicer mechanism is illustrated as applied to an airplane, not shown, having awing ll provided with an-iniiatable deicer boot 5 preferably positioned adjacent the leading edge of the wing, fluid pressure for inflating the boot being supplied thereto from a suitable iiuid pressure reseru voir 6 through the medium of conduits l, te, t, 9 and lllinterconnected therebetween, the supply of uid pressure from the reservoir to the conduit la and to the other conduits being under the control oi the pilot by means of a three-way valve il, of conventional construction, and adapted with the operating handle i2 in one position to permit the flow of uid pressure from the reservoir through the conduit l', and with the handle in another position to prevent the now of fluid pressure therethrough and to connect the conduit 7a with an exhaust conduit i3 carried by the valve. A feed valve le, likewise of wellknown construction, serves to supply fluid pressure from thev conduit 8 to the conduit 9 at a4 reduced pressure which may be selected by adjustment of an adjusting screw l5, while com* munication between conduits 9 and lil and between the conduit I3 and atmosphere is controlled by avalve mechanism l5 as shown.

rIhe valve mechanism i6 is of the fluid pressure operated type, havinga casing l? provided with an inlet chamberY I8 and an outlet chamber l separated by a ported partition 2S, communica tion between these chambers being controlled by means of an inlet valve 2i positioned in the inlet chamber and provided with a stem 22 ei;- tending upward through the ported partition into the outlet chamber and provided at its upper end with an exhaust valve 23, the valve assembly thus formed being normally maintained in the position shown to prevent communication between the-two chambers through the ported partition by means ofa spring 24 interposed between the lower side oi the exhaust valve and the upper face of the partition. The outlet chamber i3 is connectedv with the interior of the deicer vboot 5 through the medium of conduit. IQ, while the iniet chamber i8 is connected with the reservoir ii through conduit 9, feed valve M, conduit 3, conduit la, valve I and conduit i. The upper portion of the outlet chamber is closed by means of a partition Z5 provided with a bore 25 and valve operating plunger 2l slidably mounted thereon, the partition 25 thus forming, in conu nection with the casing,V an exhaust chamber 23 having an atmospheric port 29. With the plungerV 21 in the position shown, the outlet chamber I9 is connected with the exhaust chamber 28 through the medium of a port 30 formed in the valve operating element. The upper end of the exhaust chamber 28 is closed by means of a flexible diaphragm 3i suitably attached at its oenter to the valve operating plunger 21, and forming in connection with a closure member 32, bolted to the casing as shown, a control chamber 33, the valve operating plunger and diaphragm being normally maintained in the position shown by means of a spring 34 interposed between the upper face of the partition 21 and the lower face of the diaphragm 3|. Leakage between the chambers I9 and 23 through the bore 26 is prevented by means of a suitable seal 35 positioned in the bore. It will thus be seen that with the valve in the position shown the interior of the deicer boot is in communication with the atmosphere` through the conduit IB. outlet chamber I9, port 30, exhaust chamber 28 and exhaust port 29, while on downward movement of the valve operating plunger in response to application of nuid pressure to the chamber 35, the valve operating element first abuts the upper end of the exhaust valve to close the port 3E), and subsequently moves the inlet valve to open position against the spring 24 to permit communication between chambers I8 and I9 to supply fluid pressure to the interior of the deicer boot at a pressure determined by the setting of the feed valve I4, this feed valve being so constituted as to maintain the desired pressure in the inlet chamber I8 of the valve I6 at all times, regardless of the pressure obtaining in the supply reservoir S.

Novel means are provided for controlling the operation of the valve I 6 including a detector element 35, preferably mounted at the leading edge of the wing as shown and comprising a body portion 31 having a bore 38 therethrough, the outer end of the bore being closed by means of a plate 39 suitably clamped to the outer end of the body 31 by means of a clamping plate 4D, the plate 39 being provided with a restricted passage 4I for permitting communication between the passage 38 and atmosphere. As indicated on the drawing the body 31 may be suitably clamped to the leading edge oi the wing by means of nuts 42 and 43. The bore 33 is provided with a, supply conduit `44 and the latter is connected with the conduit 1a by means of a fluid-ilow restricting device 45, this device having a casing 46 divided into inlet and outlet chambers 41 and 48 respectively, by means of a partition 49 formed at the casing, this partition being provided with a port 50 connecting the two chambers and preferably of smaller capacity than the oriilce 4I located in the plate 39 of the detector 36.

lIt will be apparent from the foregoing that with the valve II so positioned as to permit communication between conduits 1 and 1a, fluid under pressure will constantly be supplied to the orifice 4I through the restricted passage 50 and conduit 44, and in View of the fact that the passage is relatively small and is also smaller than the oriilce 4I, it will be seen that a relatively small flow of uid will escape to atmosphere through the oriilce 4I at all times, without, however, appreciably increasing the pressure in the conduit 44 above that of the surrounding atmosphere. .1t is also preferable to so adjust the size of passage 5i! in relation to the capacity of the fluid pressure source E, as to prevent unnecessary depletion of the fluid pressure in the reservoir.

When the airplane is flying under atmospheric conditions conducive to the formation of ice on the wings, it will be understood that ice will also tend to form adjacent the .orifice l, and in the event the ice formation continues, the orifice will become closed, with the result that the pressure in the conduit 44 and the passage 33 will increase to the same value as that in the supply reservoir E, this pressure thus providing an automatic indication of the formation of -ice .on the leading edge of the wing vand adjacent the orice. In order that the variations in pressure in the conduit i4 may be utilized to control the operation of the deicer mechanism, a governor mechanism lil, of well-known construction is provided, the governor being connected with the conduit 44 by means of a conduit 52, and with the control chamber 33 oi the valve It by means of a conduit 53. It will be understood by those skilled in the art, that a governor of the above type will serve when the pressure in the conduit 44 is below a predetermined value to establish a connection between conduit 53 and atmosphere, and will serve when the pressure in the conduit G4 exceeds a predetermined value to establish a connection between conduits 52 and 53 and disestablish the connection between conduit 53 and atmosphere, a subsequent predetermined reduction of pressure in the conduit 44 serving to again dis-establish the connection between conduits 52 and 53 and reestablish the connection between the conduit t3 and atmosphere to exhaust fluid under pressure from the conduit 53. Thus on closing of the oriflce 4I by formation of ice adjacent thereto, the pressure in the conduit 44 will increase to a value sufcient to actuate the governor to dis-establish the connection between conduit 53 an-d atmosphere and supply fluid pressure from the conduit 44 to the control chamber 33 of the valve iii through conduit 52, the governor iii and conduit 53, the pressure supplied to the valve 33 serving to move the diaphragm and valve operating element downward to close the exhaust valve and open the intake valve 2i to admit fluid pressure to the deicer boot 5 to iniiate the latter and destroy any ice formations thereon. At the same time, the increase in pressure in the conduit di and in the passage 38, acting against the ice closing the orifice All, will eventually be suicient to break the ice, thus permitting the conduit l. to again exhaust to atmosphere with resultant operation of the governor 5I to exhaust the chamber 33 of the. valve i6 and to permit the latter to exhaust luid from the deicer boot 5. When this action occurs, it will be clear that in the event the atmospheric conditions are still conducive to the formation of ice, the oriiice di will again be closed by the ice formation and the above described cycle of operation will be repeated.

It is contemplated, however, that under certain conditions of operation, the pressure built up in the conduit 44 and in the passage 38 will be insufficient to expel the ice from the orice ai l, and consequently, a modified form of detector is illustrated in Fig. 2 of the drawings, the detector being identical in construction with the detector shown in Fig. 1 except for the construction of the oriilce plate 39, which is made of ilexible material. Although the entire right face of the flexible member 39 is subjected to the pressure in the enlarged end of the bore 38, flexing of the member 39 to the right under the action of the slip `stream is prevented by means of stops til which will ilex thev member A'sufliciently to remover ice formations therefrom, -to again openfthe forilice and to permit fluid pressure-.to escapeitherethrough. Thusitwlllbe seen that, 'inthe' event the oriceitendszto close whenfithe. construction in Fig. l is use'dfresultng in thefdeicerrnechanism becoming vvinoperative, this 'condition will be readily overcome by utilizingfithe Iconstruction shown in Fig. 2.

Referring rtolig. 43,' a fmodiedvdeicer Ycontrol is illustrated, rnore particularly adaptedto use in connection with thetcontrol Aof "deicer mechanism of the typ'ealreadyE incommon use. vHere again-a reservoir-6 isutilized 'as a source of fluid pressure 'and is adapted through themedium fof conduit 'I to be connected withfadetectorf36,fof the type shown'in Fig. Al'j through =a cond-uitM, this conduit being; providedwitha restricted passage or choke 50, corresponding to the choke illustrated in Fig. l, and preferably-'of smallerfcapacity than the orice 14| in the detectorielement."y

As lheretofore explained, -Ameans`- `are thuspro`vid ed for constantly exhausting-fluid lto atmosphere through the orifice'dl, closing of the-oricefas a resultof formation of ice adjacent thereto "resulting in anlincrease-in pressurefin'the conduit-14d j between the choke'and the -orice 4l. `Inthis embodiment of the invention the vpressure variations in the conduit 44 are--utilizedto'actuate indicatingmeans for -advising fthe :pilot of the formation of ice on thewings'fof the airplaneone of these means beingv a pressuregaugefconnectedto the yconduit-44 bymeans-of .aV conduit 5S, and'theother-being an indicator light :57, adapted to be energizedor de-energized'by means of a pressure operated switch 58, preferably con-VV structed 'in accordance with th'e principles set forth in the patent to Stephen Johnson, Jr., and Stephen Vorech, No( A11,925,762,*dated September 5, 1933and connected ywith the-conduit 55 by means of aconduit 59j "The 'switchfis provided with terminals Sil and 6|, and it will be 4understood thatv wh'enthe vpressure-to the -conduit eX- ceeds a predetermined valuefthe switch .will `be operative to establish an electrical connection between the terminals.` One pole cfa battery 62 is connected with the terminal 6l by -means-vof a wire'63, the other terminalof the battery being connected to one sideofthe lamp larnentfby means of a'wire 64 and the other side of the filament being connected "to theterminal Sil bym) means of a wire 65. -v Thefswitch 58 isprefeiablyso adjusted as to establishA a connection between the terminals 60 and El when the pressure in the conduit M rises sufciently to indicate a formation of ice on the wing or adjacent the orice 4l sufficient to interfere with safe operation of th'e airplane, and it will be understood from the foregoing that the apparatus heretofore described will serve, either through observation of the gauge 55 or the indicator 5l, to advise the pilot of any such condition in order that he may operate th'e manual controls of the deicer mechanism to start operation of the deicer in the event the airplane is so equipped.

At the present time airplanes are often lof fluid pressure, such as the reservoir 6. Vdeicermechamsm lof this type can be readily con- .strolled-'byj the control 'mechanism heretofore descri-bed, fth'ewelectric motor being provided `with terminals-:Wand Tl, 'the terminal 10 being conequipped-'with deicermechanisms wherein the .lnatonlfanddeflation of the vdeicer boot is controlled by meansfof va distributor driven by an 'electric' motor. forinflating and 'deiiating the boot lat predeterminedintervals, and Vsuch a mech- -anismifis'` illustrated in Fig.v v3, as including a slow speedelectric motori 65 having distributor valve 66 .-drivenfthereby `and adapted to alternately establish aconnection between an voutlet conduit -flieading' to thedeicer-boot and an exhaust port 'pandibetween' the outlet conduitl and a supplyconduit '69 `connected with a suitable source A nected to the lei'tend4 of the battery 62 by means of a wire l2, and the terminal 'Il being' connected pto the iwire65"by means of a wire 13. Thus, on

operation ofthe switch 58 to establisha connec- -tionbetween terminals 6i] aind! in response to anzincrea'sezin Vpressure in the conduit 44, it will be vunderstood thatthe ymotor 55 will'be ener- `gizedby the battery to drive the' distributor valve 66 and to alternatelyinflate Vand deflate the boot of the deicer toremove ice formations on the wing of;theairplane. V-In like'rnanner, when any other type ofdeicer vmechanism is utilizedythe mech- .anism-r can ibereadily controlled through the me- -diurn ofl th'e ymechanismv described, ywhich Vserves to automaticallyiindicateto the pilot the formation-of ice 'onthe wings'of the airplane, and at the same time to automatically render the deicer mechanism-.effective to removethis ice from the wing. l

Althou'ghthe. invention has been illustrated and described'herein-:with Yconsiderable particularity,

it is to be understood Vthat the sameris notlimited to the form shownbut-mayreceive avariety of -mech`anical1 expressions, as will readily appear to thosefskilledin the vart.V Referencewill, therefore, be-had=fto the appended claims fora delinition` of the` 'limits- 7of the invention.

. AWhat/isclaimed` is:

1. `Thecombination-fwith an airfoil'having an inflatabledevice-associated therewith for break- .to saidfconnection 4andvorice at a limited pressure andfor increasing -said pressure on restricy.tionfoi said-:orifice by the formation of iceadjacent-.ftheretol-and-for finally further increasing saidf-piessu-re to a value suicient to remove the iceadjfacent-the orifice, a connection betweensaid source and device,.and means associated'with said last named connection and operable in respense to the initial-increase in pressure in said first named connection due to the restriction of orifice for supplying fluid from said source to said device.

2. The combination with an airfoil havingr an inflatable device associated therewith for breaking formations of ice thereon, of an orifice positioned adjacent said airfoil and adapted t0 be restricted by the formation of ice adjacent thereto, means operable on restriction of said orifice for supplying fluid thereto at an increasing pressure which finally reaches a value suicient to remove said ice formation, and means responsive to the increasing pressure of fluid supplied to said orice for supplying fluid under pressure to said device-'for inflating the latter and breaking the formation of ice on said airfoil.

3. The combination with an airfoil having an inflatable and deflatable device associated therewith for breaking formations'of ice thereon, of an orifice positioned adjacent said airfoil and adapted to be restricted by the formation of ice adjacent thereto, means for normally supplying fluid to said orifice at a relatively low pressure and for increasing said pressure on restriction of said orifice by the formation of ice adjacent thereto and lfor finally further increasing said pressure to a value suicient for removing said ice formation, and fluid pressure control means responsive to the initial increase in the pressure of'fluid vsuppliedto said orifice for correspondingly controlling th'e inflation and deflation of said device.

4. Vrlhe combination with an airfoil having an inflatable device associated therewith for breaking formations of ice thereon, of a flexible element positioned adjacent said airfoil and subjected to the slip stream of the airplane, means for supplying fluid under pressure to said element, an orifice formed in said element for normally exhausting the fluid supplied to said element and operable on the formation of ice adjacent thereto for increasing the pressure of fluid supplied to said element for moving said element and removing the formation of ice adjacent said orifice, and means responsive to the pressure supplied to said element for controlling the degree of inflation of said device. I

5. The combination with inflatable ice removing means for an airfoil and means including a motor for alternately inflating and deflating said means, of means for controlling the operation of said motor including a conduit, means for supplying fluid under pressure to said conduit, an orifice in said conduit for exhausting fluid from said conduit and operable on restriction thereof by the formation of ice adjacent thereto for preventing the exhaust of fluid from said conduit and increasing the pressure therein, means associated with said conduit and operable in response to said increase in pressure for energizing said motor, and means responsive to the pressure of said fluid for breaking formations of ice adjacent said orifice.

6. Ice removing means for an airfoil including an inflatable member associated with said airfoil, a source of compressed fluid, means including a valve operable for connecting said source and member for inflating the latter and operable for exhausting fluid from said member to deflate the latter, and means including an orifice having a connection with the source of fluid and subj ected to the slip stream of the airplane for controlling the operation of said valve.

7. Ice removing means for a body adapted for movement in a fluid medium including a power operated element movable with respect to said body for removing ice formations thereon, a source of compressed uid, and means for controlling the energization of said power operated element including an orifice subjected to the flow of fluid medium by said body, means for connecting said source and orifice for supplying fluid to the latter, means operable on restriction of said orifice by formation of ice adjacent thereto for energizing said power operated element, and means responsive to the pressure of the fluid in the connecting means for breaking formations of ice adjacent said orifice.

8. Deicer mechanism for a body subjected to ice formation including a power operated device movable with respect thereto for breaking said ice formation, an orifice subject to said ice formation, means including a source of compressed fluid for establishing a flow of fluid through said orice, meansoperable on restriction of said flow for energizing said power operated device, and means responsive to the pressure of said fluid for breaking formations of ice adjacent said orifice.

9. Ice removing means for a body adapted for movement in a fluid medium including an inflatable and deflatable device associated therewith and a source of compressed fluid, and means for effecting a cyclic control of the inflation and deflation of said device to effect removal of ice from said body -including pressure responsive means for connecting said source and device for inflating the latter and for exhausting fluid pressure from the device to deflate the latter, an orifice subjected to said uid medium and subjected to ice formation to restrict said orifice, connecting means between said source and orifice for supplying fluid to said orifice at a low pressure when said orifice is unrestricted and for supplying fluid to said orifice at a pressure sufficient to remove ice formations therefrom when the orifice is restricted by said ice formations, and means for connecting said connecting means and pressure responsive means whereby the latter is subjected to variations of pressure in said connecting means in accordance with variations in the restriction of said orifice.

WILFRED A. EATON.

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

UNITED STATES PATE-NTS Number Name Date 1,794,690 Horni Mar. 3, 1931 2,182,530 Baer Dec. 5, 1939 2,182,547 Tumey Dec. 5, 1939 2,338,574 Cunningham Jan. 4, 1944 2,358,804 I-Iolloman et al Sept. 26, 1944 FOREIGN PATENTS Number Country Date 449,532 Great Britain June 22, 1936

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