Патент USA US2404323код для вставки
Ju1y16,1946. ~ A. c. STALEY SUPERGHARGER CONTROL AI’PARATUS Filed Jan. l, 1942 Í 2,404,323 Patented July 16,1946 2,404,323 ~ UNITED i „STATES , ,s PATENT fomce ' SUPERCHARGER CONTROL APPARATUS Allen C. Staley, Birmingham, Mich., assigner to Chrysler Corporation, Highland Park, Mich., a corporationo'f Delaware Application January 1, 1942,*Serial No. 425,298 " 12’Claims.v (Cl. 12S-119) 1. , This invention relates to an improved control ‘i ` apparatus for superchargers and associated, fuel system for internal combustion engines. Y. More speciñcally, the invention pertains to an > improved control apparatus of this kind which is , particularly adapted for superchargers of aircraft engines. ` Y Other objects of the invention are to provide an air compressing unit for creating the variable force required to oppose opening of the spill valve under diverseoperating conditions which is sub jected to substantially the same inlet air density as the supercharger and which is operated at a speed directly proportional thereto and to pro , It is Well known that axial flow as well as other vide an air compressing unit for this’purpose hav~ ing characteristics such thatthevariation of the density and volume of the air entering the inlet 10 speed at which it is driven andi the variation of of the supercharger to the discharge pressure the density of the air at its inlet produce such l ,is not maintained within predetermined limits. changes in the force developedq thereby and op The limiting discharge pressure, above which posing opening of the spill valve as vto limit the aero-dynamic `stalling willv occur, decreases in discharge pressure of the supercharger to a value value as the inlet air density decreases.. For each 1.5 vbelow that at which the latter would stall at each ñxed speed of operation of a given supercharger, speed of operation and in that air density respec~ the limiting ,discharge pressure follows a1 curve, tively within relatively wide ranges of speeds and during variation of inlet air density, which can be air inlet densities andwithout holding the vsuper determined experimentally and which is known charger discharge pressure at unnecessarily low as the pumping limit curve of the supercharger,_ value at any speed or inlet air density withi superchargers stall when the relation of - the Since, in the operation of an aircraft having an Vsaid ranges. engine provided with a supercharger, changes in inlet air density occur with changes in alti e Additional objects of the invention are to provide y»improved manually operable control tude 'and temperature, discharge pressure-alti- f tude pumping limiting curves, such as those shown inFig. 5, may conveniently be relied upon ,to establish the limiting discharge pressure above which stalling will occur while operating 'at vari means for a supercharger byv which the engine ywith which the latter is associated can be throt -tled; to provide a manually operable spill valve and a manually operable throttle îvalve in control means of this kind for reducing the supply of ' air from the supercharger tothe engine by ex One of the main objects of the invention is the ,30 `hausting a portion of such »air and by obstructing ous rspeeds and at diverse altitudes. ' . provision of control apparatusfor automatically holding the discharge pressure of a supercharger below `the pumping limit of `the >supercharger under conditions of varying speed and varying the air flow to the engine respectively; to provide a control system for the above mentioned valves which is interconnected with each thereof and adapted to sequentially operate the valves in a inlet air densities such as result from variations , » vpredetermined order; and- to» Vprovide a I control in the altitude and temperatures «at which it is system of this_kind which, in reducing the supply operated. of air to the engine from a‘maximum value, ini- y " Y A further object of the invention is‘ to provide at , tially opens the manually,> operable spill valve and the discharge end of >a superchar-ger of this kind, subsequently closes the throttle valve and which, a spill valve which tends to open under the dis 40 in decreasing the air supply, initially opens the charge pressure for'variably limiting the latter by throttle valve andsubsequentlycloses the spill reducing the pressure and increasing the volume of the air handled at diverseV speeds, and inlet air densities such as result from changes in alti i Still» further- objects of the invention are to ' tude at which operation occurs. l `; A still further object of the invention is to p'ro vide mechanism which isresponsive to both inlet air density and operative speed of the super, charger for so automatically variablyopposing opening of the pumping limit control spillvalve as to maintain the discharge pressure, throughout a wide range of speeds and inlet air‘densities, below different predetermined values correspond ingto the speed andinlet` air density above‘which _stalling of the supercharger would'. occur. ' " " valve.V . -« Y " provide mechanism in the outlet of `a supercharger for controllingthe. fuel weight regulating means ~of a liquid fuel injectionlpu'mpinresponse’to >the weight of air supplied by,> a‘superchargerto an engine; and to Vprovide mechanism of this kind which-is so located with .respect to- the outlet ,of the supercharger as to be responsive to .only that portion of the _air operated upon by the Ysuper Vcharger which is actually/supplied'to the engine. An illustrative embodiment of theinvention is shown in the accompanying drawing. in which: ’ :55 _’Fig. l is anjend elevational viewof (an internal 2,404,323 3 4 Y ' y engine by a conduit 33’ which may be connected tion. to an injection nozzle (not shown) arranged to Fig. 2 is a fragmentary central sectional view discharge fuel directly into the cylinder heads 15 Y of the supercharger taken on the line v2-'12 of or into the intake manifold “It of the engine. , Since the pressure applied in regulating theY pumpn22rthrough the bellows 23 is a function of Fig. 1. Fig.v 3 is a transverse sectional view of one ofk the blades of the rotor of the supercharger taken on the line' 3,-173Lof Fig. >2. ~ ' the'I square ofA the air velocity inthe discharge passage" I4, there isa tendency to increase the ` Fig. 4 is asectiona'l view of one' ofthestation'-V `> ary bladesV taken on the line 4-4 of Fig. A2. ` _ Fig. 5 discloses typical pressure altitude pump'- ~ V ing limit curves of ñowrtype. . ` of the pump isY variably regulated. Fuel charge discharged from the pump 22 is supplied to the combustion engine having a supercharger and control apparatus therefor embodying the inven Y _.„fuel supply in response to air flow at a greater ~ >‘rate than that desired. This is avoided by vari a supercharg'er of tha-axial"V î` „ablyñop'posingthe action of the bellows 23 upon . I» -.~ A Y the bellcrank 29 by the action of a rod ‘I5’ which `, Fig. 6’is a sectional view taken on the line 3-.-S 15. A`is attached'at one. end to a bellows ‘I6’ confined ' Y in' a'chamber 1l andv to the bellcrank 29 atiits ofV Fig. 2. Ä Fig. 7 is an enlarged- sectional View of the spill, 4- - opposite end. The interior of the chamber ‘l'I is valve and control therefor. ‘- ' " “` ` ` connected by a conduit 'I8 with astatic Pressure In the form of the invention illustrated in the? I Vchamber 'I9y which communicates with the fuel drawing, the‘improvedfsupercharger control ap 20 line 80 leading to the inlet side of the pump 22, The interior of the bellows 'i6' is connected by _a paratus embodying the-invention is illustrated. as conduit VSI with a venturi 82'arranged concen applied to a supercharger,”generally designated trically of the> fuel line 83. The .venturi 82 sub `byïthe numeral I0, of the axial flow type which ' jects the interior 'of the 'bellows »to changesv of is illustrated in connection with an internal com bustion engine generally» designated bythe nu 25 pressure in proportionto the'fuel ?low through the conduit 8i). The bellows 13’ thus acts to re -meral II suitable `for propelling aircraft and of duce the fuel increasing action produced’ byÈ the the type which has a -fuel system injecting _fuel bellows 23 as to prevent the fuel-air ratio from into the engine manifold or theengine cylinders. excessively increasing Ywith increased air iiow.> The supercharger I9 comprises a YVcasing 1I2 having an air inlet I3 at one e'nd and a discharge 30 This control mechanism is therefore Apredeter mined to maintain a -fuel-air ratio as demanded chamberand air outlet I4 and I5 respectively at by engine requirements 'under' a wide Irange of itsl opposite end.y Extending centrally through the casing I2gis a shaft VIgIî'journalled in suitable bearings Il and I 8` and on which are ñxed a ` series of air propelling elements I9’eachV provid ed with fan blades 29. ' The fan blades 29 of suc operating conditions. ‘ l ` ' " ' ' l Privide at the inlet end of the discharge cham 35 ber'I`4 is an exhaust'outlet 3l 'leading to the in terior of> a casing 32 `and having'an opening 33 communicating with atmosphere. The wall of cessive air propelling units I9 are of such shape and pitch as to progressivelyincrease the pres the casing 32‘has a valve seatv against 'which fa va1ve'34 bears. The valve 34 is normally held in sure of the rair passing from the inlet I3 to the discharge chamber I4 in successive steps. Fixed 40 closedposition by >a bellows 35 to the interior or' which air under pressure is supplied through a blades- 2I carried by the casing I2 "arelr disposed -between blades of successive air propelling units I9 in order to properly direct the air propelled by the blades >of/one unit for `further propulsion of the next'successive unit. -V ' i conduit 39. The air-supplied'vthrough the con-v duit 36 is impelledlbyY a pilot blower _generally designated by the'nu'meralï31ywhich includes a 45 casing 38, an inlet 38a, and rotor 39. Therotor 39 is driven in timed relation to operation ofçthe » Air under pressure delivered by the final air propelling unit I9 Vis received in the discharge chamber I4 from which it flows through the'ou‘ supercharger»fwhichf'm'ay bel' 'driven in timedV re` lation to the crankshaft'ofthe engine Il.y The supercharger lalso may be driven in 'any vmanner let I5 to the manifold> of the engine II. i - ì The weight of liquid :fuel supplied to the engine 50 from any> suitable power sourcebut’for l`-p`urposes is’proportioned with respect to the weight of» air fed thereto from the vsupercharger by» suitably t controlling the discharge _of liquid fuel from a variable liquid fuel pump of conventional con struction, generally designated by the numeral 22. The control vapparatusby which this is ac of illustration the drawing shows ai drivevfojr the supercharger comprising ïmeshedfV bevelled :gears 49' and 4I on the supercharger shaft I ß andon> an intermediate driving shaft 42 respectively» 55 The intermediate shaft 42^is drivingly< Vconnected. with the crankshaft 43 of' the engine by bevelled complished comprises'a bellows 23 contained in gears 44 arid 45. V Mounted; on the shaftn I6 of the a casing 24, the interior of which is connected by sup'erchargerY is a worm 45 which is meshed with a pipe 25 with the interior of the discharge cham- v a worm gear 41 on vthelower end _of a shaft48. ber I4 so as to maintain pressure inthe casing 60 The upper end of; the shaft 48Afis drivingly con nected to the rotor 39 of theA pilot lair compressor 24~`proportional to the air pressure in the dis charge chamber I4- The interior of the bellows 23 is connected by `a pipe 25 with the Venturi tube 21 disposed centrally of the passage through the discharge chamber I4 in order to subject the interior of the ‘bellows to. pressure changes in pro portion to changes in velocity of air ñow through by'suitable Ygearing 49,u ' ' ‘~ ‘ Opening> of" the pumping > limit control spill valve 34 is thus variably opposed bythe discharge pressure of the pilot compressor 31- which inturn varies in accordance with‘looth> the speed .of- op erationof the supercharger and with variations in the density of the air> supplied to the Apilot compressor.V The pilot compressor is .of such con Venturitube is so located'as to be responsiveonly to that portion of the air operatedjupon byithe ‘ 70 struction that during all speeds -at" which it is lsupercharger which is actually fed- to `the engine.` driven it' operates ‘Well'fwithin its -pumping or theidischarge chamber and to the engine.YAY The Theibellows 23»is mechanically connected with surging limit.y The pilot. corrlpre'ssorA mayjcom a stem" za attached to the bellows 2a and to a bellcranlá`29 which is in turn connected with' a output ofwhichisì predetermined lby î't‘sfconjstruc pris’e‘anvaxial flow or centriiugaltype'blower, the ' 'control rod‘t'e by which the quantity'óf Yfuer dis-ii 75 tion to sdv‘ariabl'y"opposë’opening’of tha-‘pumpi p 2,404,323 ing limit spill valve 34 as to prevent the discharge pressure of the'supercharger I0 from exceeding that value at which aero-dynamic stalling occurs throughout relatively widecorrelated ranges of operating speeds and inlet air densities. This is open valve 52. l.Further movement of. rod‘53 to the left causes „further movementto the 'leftwof abutment 64,- and. since this abutment'` is _nowin l ' engagement ‘ with lever 55, `counterfclockwise movement of the;lever.55 and valve 5.2 takes place with the valve 52 reaching closed position. A discharge pressure vfar below its pumping limit stop, not shown, prevents movement of the valve during any operating conditions. l 5I beyond open position. The abutment‘65 `moves The inlet end of the discharge chamber I4 is tothe left away from the lever 54. >Theabutment provided with a second exhaust passa-ge 50 in 10 62 also moves to the left,.but this is possible be which is disposed a valve 5I for variably obstruct cause the spring 5I can be and. is.` compressed. ing vthe escapement of air from the pressure The rod 53 has now reached an extreme left po- " chamber I4. The outlet I5 of the discharge sition, in which the valve 52 is closed, and the chamber I4 islprovided with a throttle valve 52. valve 5I is open. Thus the supply of air to the The valves 5I and 52 may be manually regulated 15 engine is further reduced, not only because the for changing the supply of air to the engine by valve 5I is open, but also because the valve 52 a common actuating rod >53 which is shiftably now obstructs passage of air to the engine. ' > mounted in supporting structure (not shown). In order to prevent the discharge air pressure from exceeding a selected value under any Vop The, valves 5I and 52 are operatively -connected by operating levers 54 and 55 respectively with 20 erating conditions, a safety valve SI5V is provided in an opening 61 formed in the wall fof?thel ex the control rod 53 in suchv manner that when the haust passage 50. TheAvalve 66 is normally held throttle valve 52 is 'fully ppenedï as illustrated in y'in closed position by a spring (iB-.and is> adapted Fig. 2, the escapem'entfvalve 5I is'fully'¿ closed. This is accomplished‘by providing on the rod 53 to open under the discharge pressure when'.the a collar 56 and a shiftable abutment 51 between latter exceeds a selected value. . Y e which is disposed a coil spring 58.' The coil Although but one specific embodiment of the spring 58 urges the shiftable abutment 51 against invention is herein shown and described, it will the operating lever 55 of the valve 52 when the be apparent that various changesl in -the'siza control rod 53 is in the position'shown in Fig. 2 shape and arrangement of parts may be made thereby holding the lever 55 against a stop 59 and without departing from the spirit of the inven retaining the throttle valve 52 in open position. The escapement valve 5I is similarly held in What is claimed is: _ closed position under the `vabove conditions by a 1. In a supercharger for supplying air to an accomplished‘without unnecessarily limiting the tion. shiftable abutment 60 which is urged leftwardly ' ' ` internal combustion engine; apparatus for main as viewed‘in Fig. 2 by a coi1` spring 6I bearing 35 taining operation of said supercharger within its- ` against the collar 62 on the rod 53. ' Provided on the rod 53 is a ñxed abutment 64 which is spaced rightwardly, as viewed in Fig. 2, from the shift able abutment 51 in order _to allow lost motion pumping limit throughout relatively wide ranges of operating speeds and inlet air densities re spectively including a spill valve for discharging , air to atmosphere subjected on one side to and action between the control lever 55 and the rod 40 adapted to be opened by the discharge pressure of said superchargen‘and means responsive to 53 during leftward movement of the latter as changes in both the speed of operation of said su viewed in Fig. 2.~ A similar abutment 65 is pro percharger and the air density in the vicinity of vided on the rod in spaced relation to the shift its air inlet for variably urging said valve toward able abutment 60 in order to allow lost motion action between the rod 53 and the operating le 45 its closedA position with a force varying directly in accordance with speed'and directly with re ver 54 of the escapement valve 5I when the rod spect to inlet air density. " ' 53 is shifted rightwardly as viewed in Fig. 2. 2. In a supercharger for supplying airV to' an In the foregoing control apparatus, when the internal combustion engine; apparatus for main maximum supply of air is beingA fed to the- en@y gine, the escapement valve4 5I is closed ‘and the 50 taining operation of said supercharger within its pumping limit throughout relatively wide ranges throttle valve 52 is fully opened asl illustrated in of operating speeds and inlet air densities respec the drawing. In this positionthe spring _58 is compressed, and the abutment 64 is «spaced ri'ght- i tively including a' spill valve subjected on one side to and adapted to be opened Aby the dischargewardlyof the' lever 55. The control ¿rod 5_3is‘in an extreme right position. Movement fof the rod 55 pressure of'said supercharger, and'means respon 53 to the left causes the collar; 6:2 to be moved to the left, the collar 62 acting through the spring sive‘to changes in both the speed of operation of said supercharger and its inlet air density forr 6I to move the abutment` B0 tothe left. f This , variably urging said valve toward its closed posi tion with a force varying in accordance with causes the lever 54 to be rotated counter-clock wise, and the valve 5I to be moved to open‘posi# .60 speed and inlet air density,` said means including anair pressure responsive element operating on tion. The abutment G5 also moves to the left the other side of said valve, a pilot air compres with the rod 53,' thereby permitting the above to sor having an air inlet subjected to substantially ' happen. In the meantime the abutment 64v has the same air density as the air inlet of said su been moving to the left and has flnally reached percharger and having a discharge outlet con the lever 55 but has not moved the lever 55 nected with said element and mechanism for counter-clockwise so as to disturb the open po driving said pilot air compressor in timed rela-> sition of the valve 52. The collar 5E has also moved'to the left, but the spring 58, because of f tionship with respect to said supercharger. 3. In a supercharger for supplying air to an its expansion from a compressed state, main tains the abutment 51 in engagement with the -70 internal combustion engine; apparatus for main taining the discharge pressure of said super lever 55, thereby maintaining the open condi charger within the limits of a definite predeter tion of the valve 52. Thus the rod 53y is in an mined pumping limit vcurve-throughout a sub intermediate position, and _both valve y 5I and valve 52 areA open. Opening ofthevalve 5I de creases the ño'w» »of lair toï'the 'engine past the stantiallyA wide range of inlet* ai-r vdcnsitieslfor each of a plurality of operating speeds-cisaid 'su gnomes 58 percharger` .includingQa -spill valve sulaiíected` on tuating said', valves and ‘means voperativ'ely. corn one sidel toand adapted to be opened yby the dis" charge pressure" of. said 'superc-zh'arger,` means re-. necting. saidA rod 'with ‘said’ mainioutlet 'and es cap'e‘ment Valves respectivelyinchiding fa .valve operating lever' associated with each. ValveV and spaced yield'able and; ñx’ed elements ‘on opposite sidesv of' “each of' "said-_Lievens "r'e‘spèctivelyç lsaid yieldable 'abutments îbeiïng ‘adjacent each other and adapted toacconìmodatemovement of each Y sponsive to. >both the speed. of operation. îof‘said su¿1;>erchargerV andv .its vinlet air density. lfor Vari V,ably‘opposing'opening of> -said spill valve includ' ing a pilot air 'compressor driven in timed. rela tion to- said super-charger. laiidan air :chamber connected Withfthe discharge thereof, forapply ing a valve closing k:torce on the opposite side >‘ci said'spilLvalve.> ' ’ c lev‘e'r by? itsV associated ñXed abutment While theother- lever remains at rest during movement of“ saidl rodf in respectively-'opposite ~’directions ‘ throughout; a , predetermined portion of-` its range 41111 a supercharger for supplying air to. an interina] combustion engine; apparatus for mainn taining the discharge .pressure of said: super of‘move'ment. ` , , , « 8.~ The method «of maintaining operation-'of charger'within the limits. of a definite predetere 15 a supercharger for aninternall combustion en"-v gine` within its pumpingl limitV which- consists in minedpuanping llimit curve throughout a sub variablyfd-ischarging air to atmosphere` from the dischargefcharnber ofv saidsupercha-rger, andA var lably opposing such discharge of airl autolrlati`>cally in accordance with variationsinA the Vinlet air; density andspeed of operation of» said super stantiallygwide 'range oiinlet air densitiesfor each. of Ya plurality 'of operating. 'speedsï’of said vsupercharger including a spill valve'subjected on oneìside to andadapted'tobe.opened by,- the dis-v v chargé; pressure of said> supercharger', meansree 'sponsii/ÍeV toiboth the speedf'o‘f operation of said charger bythe force of aïsource‘oi> airpressure Varyingv in pressurefdirectly with respectto Vari superchargerand its inlet air dens-ity for Variv~ ablyxopposing opening of said` spill valve including ations in 'speed _ of operation , ofV 'said ~ supercharger a pilot air compressorfdrivenin timed relation to' 25 and inversely with- respectfto variations- in the altitudejat which it is operated; sai'clrsupercharger andanair cl'iamberA connected 9. AA fuel and, air charging systeml -for an-«in ternal _combustion engine comprising-_; a variable liquid fuel pump having a> control'memberffor /Withjthe discharge thereof;V for applying ava-ive Vclosingforce on the opposite Y'side ofjsaid spill Vvalve, said'air compressor being so constructed and drivingly connected l»with saldi sup‘ercharg r 30 predetermining the Weight: cfjA fuelv ldisclfrarged therefrom, an axial flow superchargerhaiìing an as to operate well Withinfits pumping limit air inlet -andj ai» compressed air outlet communi' throughout the operating rangejiof said- supercharger andk throughout the variations of the cati-ng with said engine andfrincluding pressure and y»pumpinglimit control mechanism hai/ing air inlet air density towhich it is subjected'in nor-> mal operation».V Y Y 35 Y 5. In a supercharger for supplying air to an spilling outlets spaced onthe up stream s_ide of said compressed air outlet, and apparatus _for ac. tuating said . fuel Ypump -Àcontrol4 member includ Vinternal combustion engine of an aircraft; ap ing; an_¿ element responsive to „anyV condition-1 and located in the air stream ¿propellediby' said super charger between said airfspill'ingg outletsandsaid paratus >for maintaining the discharged pressure of said supercharger Within the limits of a definite predetermined pumping limit curve during opera 40 compressedI air outlets, said element being sub tion at a substantially Wide range of altitudes in jected-to the/action ofi-only -that portion of the cluding a Valve for' exhausting air from the dis air operated uponlby said supercharger which is discharged »from vsaid .compressed air outlet. charge side of said supercharger adapted to be opened by discharge pressure,v and mechanism for urging said valve toward closed position with -10. Afueland air charging systeïnfór änin tern'al combustion e?ginecòlñ'ñris'iñg a Variable liquidfuel pump having vavcòntrol «iìiemberfor preclet'erinini?g> the weight.v of- fuel. discharged .force oit-variable magnitude, said mechanismïbe ingfso constructed and, arranged‘as to lvary- said ' force inversely With respect to variations in alti tude and directly with respect tovariationsin speed ofy operation of said compressor.- , therefrom, an ~ axial flow ,supercharger ha'iîing van 50 air inlet ¿and à comprëss‘ëdiàîr öiïtl'ê't. Öôî?'?iìlîi catihgäwïthesaid engine, mechanism fòrÍ Öonf?öl ungîtnesuppIyî of air, from' said-Compressed'au Outlet Comprising a Variab1è._ throttle Valv'èiñ Said outlet and a variable air spillingputlet spaced ,on the up stream side from said'compresseu air-'out V6. lnasupercharger having a dischargecham uerpgovided wit-ha main outlet for»gsupplgying> air to an' internal combustionA engine and an escape. ment outlet for discharging air r-tovatmosphere", mechanism for controlling the Lsupplyßi air; to saidl engine including avait/ein said-_ main outlet, a valve in said escapementoutlet,k and »control , corîtrol‘mëmbver including an elementrresp'orïsiìle apparatus-.for‘opening and closing said valves in predetermined sequence,- fsaidfcontrol apparatus to >air conditions and- located, between said. air spîllil’lgY Outlet á?ldsaîd Compressed ai? Outlet, said/element being'subjettedto the actìonof that being so constructedîand arranged as;> toY initially positively open said--escapement valve and sub? . sequently close said main‘val'ige during reduction ot the> supply of air to said engine froma-.maxi-> mum-toga minimum value andtoj, initially’open said. main valve and-_subsequently positively close saidlescapement Valve during increasing of the ' supply'ot air to said engine ironia minimumV toa maximum Value. » '7. In a supercharger having> a discharge cham 65 portion onlyA of__ thel air. operated nlip'òri . by said superchargerwhich is discharged from' said coin pre's’sïed‘ all", Outlet. 1l.,k A fuel and airv chargingsystem for anin ternalco'mbustion _engine comprising a _Variable liquidI fuel .SupplyV system having ,a control mem ber for predetermining the weight of `fuel dis charged ~ therefrom,_> a /superchar'geii having' an airmiet and ai compressed air, outlet communi ber> providedwith a'main outlet. forgsupplying air 70 eating» with said engine,`r mechanism> for' con trolling the supplyv of. air'ffrorn, said compressed capenient ïoutlet,> mechanism Lfor* controlling> the air outlet comprising. aV variable.. throttle. valvein supply of A`air to «said ¿engine `including -af valve said outlet f and»_an:> air .spilling Íoutlet ,spaced ‘on toy an internal combustion engine and- an es - ineßaidìime-in Outlet@ @Wein-.Said ,escapement the upstream sidefrom-vsaid compressed‘air out 75 let; andapparatus »f‘fonactuatinggsaid -fuelfsysteni 2,404,323 10 control member including an element responsive within its pumpmg limit Which consists in var iably discharging air to the atmosphere from the spilling outlet and said compressed air outlet, discharge chamber of said supercharger, and said element being subjected to the action of that Variably opposing such discharge of air-*automat portion only of the air operated upon by` said 5 ically and directly with variations in the inlet air supercharger which traverses said location. density and directly with variations in speed of to air conditions at a location between said air 12. The method of maintaining operation of a supercharger for an internal combustion engine operation of said supercharger. - ALLEN C. STALEY. '