US2657708A - Pulse jet motor fuel inlet valve construction - Google Patents

Description

Nov. 3, 1953 .w. l. E. KAMM ETA]. 2,657,708

' PULSE JET MOTOR FUEL INLET VALVE CONSTRUCTION Fiied Nov. 28, 1949 if 27" a II'IZQf/AlIV/l/AI Z9 [Z Z mmm\\\\ ma m lliiii'. Fil

Patented Nov. 3, 1953 'zi'esmos mouse-3m Momon FUEL mum oonsrmucmon 'w n baie 1' and, 1 1. ,Krautter, Dayton, and urt iStaigen, wrzi iit-na ieison Ai'r Force Base, Ohio Application. Novombems, Mia-serial No.; 129;862

: c aims. 101. 137- 5121) "(Granted under 1 rho invention lclescr-ibetl herein may be manufactured and used by or ior tne eoverninen't for governmental purposes without payment to us of any royalty thereon.

This invention relates to pulse jet motors :of

for increasingthe aecelerating action of -the 'fu'el inlet valves that are norn' ally elose'd by-the-oim bust-ion :ohamb'er pressure head and opened 'by' the reduction of combustion chamber pressure and fuel mixture inflow 'illl'id t h eombuetion chamber. Y Y

A further object is the provision of resilient actuator means for the valves which: are sep arate from the valves, for "converting {the lkinetio' energy of the valves incident to'inovem'ent there of into deformation of the actuator mean and 1 then utilizing this kinetic energy to 'aooeieiat'e the .returnmovement .of .the valves 5170 their opposite positions;

- A still ,further .objectfl-is ;.the ,utilization ofmesilient aotuatorimeansifor{accelerating ,thez-move-v ment of the ,=fuel inlet valves :in one; clirection and-"then accelerating the movement-f &the valves; 3 in the opposite directioninea substantially ituned resonant ifreguency relative to 'the =tunedocombusti'on :pulse :jetI-cycle frequency.

iAciu'rther ObjBGt is the provision to; tosnient pulse jet cycles of the motorier deeelerati g 5 the movement'of the valves in one direction and actuator means located at opposite sides of the 1 fuel imixture =inlet check valves maving a predeh- I terminedmuned frequenoy which issulostaht 113i 5 accelerating the -valve -movement" in th e 'oppo'site direction incident to impingement of 'th valves against the resilient actuator=means, therehv 015- tai'ning f aster'and-moreemcient valve aotuations for improving the efiioiency and operation'offiie Y f resonant 'pulse et cycle of I a pul'se et'inotor; Other objects 'ani'i advantages 'of thei'nventi will appear, from the following, des fip n,

in connection with the accompanying drawing wine 3-5, -U. :s. @0310 x1952),

isee. zse) in which like reference 'ciiaraoters refer to like parts in the 's'evei'al figures:

"Fi re'i a somewhat tl-iag ralnmatie Side 1e vation of a resonant =nu1se jet motor inoorisorat -il'lg' 't he invention, parts thif being "broken away anti shownin seotionj Figure is an enlarged, fiaQ-Iiintai'y=-ve1 tioail cup shapeti =fu1 inlet control vawes in then closed positions in full lines, and in open' ositions in dotted lines;

Figures 3 and 4 are fragmentary vertieal'see tional views illustrating a modified embodiment of cup sha ed eheck valve and valve seat ra'ngement, moorporating iesilient valve actuators having a-predeterinined-tune treiiueneyio'r accelerating "the cheek valve movement toward each of their opopsite positions and then cleoeleratir'rg the valve movement, Figure 3 illustrating the valves in "their clbsd -1')O$itioh With the lDWi spring actuators undertension ar'ldi 'eadyto ae= celera'te the opening movement of the valves, while Figure 4 shows the upper "resilienta-otu =ators "tensioheli, following the accelerated i-valve i return movement, and ready to accelerate the return movement of the valves to "their lsihg positions, as shown in Figure 3.

"Referring to Figure 1 of the-drawimgthe -rei= erence numeral I denotes an acoust'ieally {tuned resonant frequency pulse {jet motor 'h-avin'g a combustion sham-her '2', o, discharge or tail pipe 3 witn'o disohalge outlet '74 opening into a -ooni cehtriea lly arrangetl-vehturi nozzle "5. A check waive unit =6, incorporating -our improved *Ghek valve structure is secured across the loase fuel mixture opening 1, in *the oonibustionehamber 2, a downwarlilvtapered airandfuel -'inlet -miiiizig tube :8 bejing secured across the 1owei -iaoet of the valve-unit 6. The ttib'e 8"is *formed with-an outwardly flared moutn-or-'vehturi opening 9-and a -fu el jet this s ppo ted mithe venturi s lo a 1 suitable spider; with-its fuei j-et o eninguoeateqdirectlyfbelowga deflecting,orfbaokpitessure, pr

iventiiigfbafli t'l oa rieeby?t e*tot a on sup: porting'arm's. Afful tank T2 is conneoteii-toa carburetor la'by a,pipe M, supiilvingiuerthrough'- a shutoff valve 1controlledeonduit It 'ito theflfuel ,jetji ozzle =|n. 'r1iis arrangement jdiscloses a; t m ple "form" of resonant pulse fjet motor, for illus trative purposes, which our improvedgoheek' valve 'strugtiire't is jet cycle in the conventional manner by directing a jet of air through the venturi 9 to withdraw fuel from the fuel jet l and inject the air and fuel combustible mixture through our improved check valve structure with minimum resistance into the combustion chamber 2 to form an explosive mixture therein, The explosive mixture thus introduced is initially ignited in any conventional manner, such as by a spark plug l8 which is supplied with high tension current from a spark coil l9, upon closing of the switch 29 connected to the current source or battery When the pulse jet motor is started the inertia of the rapidly ejected exploded gases moving through the tail pipe 3 finally creates a low pressure area or partial vacuum within the combustion chamber, causing the flow of a fresh explosive charge through the check valve plate 6. The partial vacuum now created in the combustion chamber causes a rapid return of the later portion of the previously ejected hot gases entering the tail pipe to return back into the combustion chamber, causing a rapid increase in pressure within the combustion chamber, producing some compression of the fresh gaseous fuel mixture introduced therein. The returned hot gases and the hot condition of the combustion chamber cause the ignition and explosion of the fresh gases and the resonant pulse jet cycle is then repeated and continued very rapidly. The spark ignition means and the air blast jet are turned off after the starting, since they are no longer needed.

It is conventional to use thin leaf spring closure valves in resonant pulse jet motors to control the fuel and air intake ports, but since these valves open under spring tension and also close because of the spring tension, and are fiat, they must be made strong and therefore must be still, in order to withstand the explosion forces within the combustion chamber. terial pressure reduction within the combustion chamber is therefore necessary to open these conventional leaf spring valves and this tension, plus the inertia of the valves, causes a somewhat late opening action. Thespringtension of the conventional leaf spring valves also cause them to close early, or before the combustion cham ber pressure changes from a positive to a negative pressure value. These conditions reduce pulse jet motors, also limiting the rate or possible number of pulses per unit of time that can ordinarily be obtained.

A ma- By employing our improved valve arr angement, utilizing circular, very thinself ,sustaining cup shaped valves,leach having a somewhat spherical contour, as disclosed in Figures 2 to 4, and forming them of suitable very thin temand protuberances facing each other, formed with surface contours similar to the valvesurface contours and'having fuel inlet openings therethrough as shown more particularly'in Figure 2', it is possibleto greatly improve the efiiciency of resonantpulse jet inotorsi formed withsubstantially sphericalinterior and exterior contours. The valves 2| seat in complemental shaped depressions 2| formed in a valve supporting plate 22 having fuel inlet passages 22 passing centrally therethrough. A valve retainer plate 23 extends across the entrance to the combustion chamber 2 in superimposed spaced relation to the supporting plate 22, the cup shaped valves 2| being freely movable vertically therebetween. The retainer plate 23 is. preferably formed of thin sheet metal stock by stamping and is foraminous, having a multitude of small fuel inlet apertures 24 therethrough. The plate 23 is also formed with downwardly projecting spherical protuberances 25, each having a spherical contour shaped to fit the interiors of one of the cup shaped valves 2|. The valves 2| are free to move between the supporting andiretainer plates 22 and 23 and fit either the protuberances 25 or the depressions 2|.

Immediately upon reduction ofrpressure within the combustion chamber 2 the valves 2| will unseat and float upwardly on the incoming fuel and air mixture passing through the inlet openings 22* toward the combustion chamber 2, the valves 2| being retained against the retainer plate 23, and on the protuberances 25, deflecting the gases laterally through the many openings 24 in foraminous plate 23, and are actually held up against the plate 23 by the suction within the combustion chamber which is effective through the apertures 24 that are covered by the surface of the valve, as illustrated in dotted lines in Fig. 2.

Following the fuel intake cycle and the return of the gases through the tail pipe 3 into the combustion chamber 2, the pressure within the combustion chamber 2 increases from negative to a positive pressure and thevalves 2| freely drop to their closed positions on the supporting plate 22, closing the intake opening 22 as shown in full lines in Figure 2.

Since the valves are very thin, light, and are sions 26 formed therein with central fuel inlet passages 22 connecting the depression 26 with l the space below the valve unit.

An upper or Valve retainer plate, as indicated at 23, is provided which is somewhat'thicker than 'the platei23 in Figure 2. The retainer plate 23 is provided with downwardly extende ing short posts, standards, or spring ,supporting means, located concentrically of the enlarged depressions 26. Intermediate the posts 2?, the plate 23 is formed; with fuel inlet ports 24 ofsufficient area in theaggregate a to permit the free passage of any fuel mixturepassing-through the apertures 22= in the valve supporting plate 22?. Located on each of the posts 21, in parallel spaced relation to the lower-surfaceof there-i;

tainer plate 22*, is a thin tempered resilient valve return disk 28, the disks 28 having diameters exceeding the diameters of the cup shaped valves 2 A thin resilient, temiered valve return jplate,

5 or sheet 2-9 is secured across the upper suidace ef the "valve supporting plate :22; "The plate 22 :is formed with circular openings '30 therethrough, each opening being disposed concentrically to the depressions l liyand the;fuel inlet ports 22, each opening 30 :ha-ving a diameter somewhat 1885 than the diameter of the m-p' shaped valves 2 I. The thickness and resiliency of the valve spring return plates and disks :29 and 128 are important, also :the relative ever hang or extens'ion 0f the plags or :the periphery; of the disks beyond the edges of :the depressions 26 and beyond "the supporting posts 21. TIIh'e pulse jet resonant cycles "of the pulse j-et motor are tuned, of 1 course, in the-conventional man-- nerf by properly proportioning sthe ilength and diamter of the tail-pipe 3 relative the :areaiof the combustion chamber to produce the desired resonant pulse jet freguencm Within limits, the shorter and larger the tail pipe, the more rapid are the resonant pulse jet cycles. Making the tail pipe longer, and/or smaller reduces the resonant frequency of thepulse jet cycles. When using a veryhighresonantfrequencythe resilient spring portions of the vailvdreturn or actuator plates are proportioned, relative to their thinness, .over :hang and the .kin'dlof- :material used, s'oas to be tuned to the resonant frequency of pulse jet cycle employed After the firstexplosion within the combustion chamber 2 takes place, the spring actuators 2B and z8 operating at their corresponding natural frequency, "equal to the resonant pulse jet irequency, will toss-the thin light cupxshaped valves 2-] back and forthbetween their open and closed positiones, permitting --a faster valve actuation than wouldbe thecase-if-the tuned resilient valve actuators "were notusedt since the movementis faster a better tuel inletpycleis obtained. As the explosion occurs in the combustion chamber 2 the cup shaped valves 2| are'forced downwardly tensioning the overhanging portion of the lower spring "plate 2'9which surrounds the valve seat and fuel opening -30 therein. The resilientaction of the plate, :as :theiexhaust cycleiends, quickly tosses the valve 2| against the .upperspring disk 28, and assisted 'by the partial vacuum [in 'the combustion chamber, the upper/disk 18 ten sioned as illustrated in Figure 4. "when the neutral pressure in the combustion chamber quickly follows, the spring disks 28 quickly tosses the cup shaped valves 2| against the lower valve return plate 29, about the time that the explosion occurs, causing the portion of plate 29 surrounding the valve as seen in Figure 4 to be tensioned and the cycle is repeated.

What we claim is: I

1. An inlet valve construction comprising a valve supporting plate having a plurality of valve receiving depressions formed in its topside, having inlet openings extending through the plate in communication with the valve receiving depressions at the centers thereof; a valve retainer plate fixed in parallel spaced relation above the topside of the valve supporting plate, having valve engaging projections thereon facing toward the valve receiving depressions in substantailly axial alignment with the centers of the valve receiving depressions and formed with a plurality of outlet.

openings extending therethrough from the space between the valve supporting and retainer plates;

lightweight cup-shape thin walled valves disposed intermediate the valve receiving depressions and the aligned valve engaging projections for free oscillatory movements between the supporting retainer-plates, said valves being fomietl" with-outer and inner spherical contour=surfaces for seating respectively in the valve receiving depressio-ns, and on the valve engaging projections and leaf springmeans-carried by each of -the valve engaging projections in spaced relation to the valves when seated in said depressions and projecting into th'e path of movement of each valv'e toward the-valve engaging projections to be tensioned thereby upon movement -cfthe valve to ward the valve eng aging projections to assist in return -o"f the valves toward the valve receiving depressions. 9

"2. inletvalveunit comprising an i let valvesupporting plate havingan upper surface and an upwardly extending annular supporting flange projecting therefrom-saidupper surface having a plurality of "inlet valve receiving depressions formed thereinwith inlet passages extending from the ib'asesof -'the'depressions through the plate; a valve retainer plate seated on -the supporting flangein parallel spaced relation to the"uprner surface 'ofthe valve -supporting plate; resilient valve" engaging means proj ecting toward 'the valve receiving depressions in the valve supporting plate and substantially axial alignment with the centers of the depressions, each resilient valve engagingmeans comprising a supporting standard projecting from the retainer plate 1 toward the center of one of the valve "receiving depressions and a "thin flexible resilientvalve actuator-disc fixed on the supporting standard in substantially parallel spaced 'relationto' the valve retainer plategsaid disc havingadiaineter slightly grea'ter than the diameterof the valve to beused; a thin resilient valve retainer and actuator "plate disposedin parallel relation to the upper surface of-the valve-supportingpla'te and extending at least partly across the valve receiving depressioiis in spaced relation to the bottoms of the depressions; 'said resilient retainer and actuator plate having'circularvalvereceiving openings extending therethrough fin concentric alignment with the centers of the valve receiving depressions; said openings being-smaller than the diameter-of the valvesto be used rigidthinwalled cup-shape valve members, "each having acircular 1' rim facing toward one 'offsaid" resilient 'actu ator discs 'near its periphery, fore-impingementwit'hthe resilient disc near its periphery incident to movement of the valve members toward the retainer plate, said valve members each having a substantially spherically curved lower surface intermediate its rim and facing the resilient valve supporting plate for impingement with the resilient supporting plate at the edge of the circular valve receiving openings therethrough, incident to movement of the valve members into the valve receiving depressions to close the openings and tension the resilient supporting plate portion in the depressions surrounding the valve receiving openings for projecting the valves toward the resilient actuator discs upon reverse valve movement.

3. Apparatus as claimed in claim 2 in which the resilient actuating portions of the discs and the resilient valve supporting portions of the resilient valve supporting plate are resiliently tuned to a predetermined vibration frequency.

4. In a fuel and air inlet valve construction for a resonant pulse jet engine; a valve supporting plate having valve receiving depressions valve supporting plate, next to the side thereof having the valve receiving depressions therein, said valve supporting plate having inlet ports extending therethrough in communication with the interior of the valve receiving depressions; cup-shape valve elements freely movable in both directions between the retainer plate and the depressions in the supporting plate, between positions in the depressions closing the inlet ports and positions out of the depressions opening the inlet ports; spring means carried by the supporting plate in spaced relation to the valve elements when moved toward the retainer plate and projecting into the path of inlet closing movement of the valves to be tensioned thereby for projecting the valves when seated in the depressions toward the valve retainer plate; and spring means carried by the retainer plate and positioned in spaced relation to each of the valve elements when the same are in engagement with the first mentioned spring means and projecting into the path of inlet opening movement'oi' the valves to be tensioned thereby incident to valve movement away from said valve receiving depressions for projecting the valves toward the valve receiving depressions, said spring means having a predetermined tuned vibration frequency.

5. An inlet valve construction for the fuel mixture inlet of a resonant pulse jet engine having a combustion chamber and communicating tail pipe tuned to a predetermined resonant pulse jet cycle frequency; said valve construction comprising a valve supporting plate having enlarged valve receiving depressions formed in the upper surface thereof and inlet passages extending through the plate in communication with the bases of the depressions; a valve retainer plate disposed in spaced parallel relation to the supporting plate and carried thereby, having outlet passages therethrough, spring supporting posts extending from the valve retainer plate in axial alignment with the centers of the valve receiving depressions; resilient valve actuator spring members carried at the ends of the posts and projecting'laterally over the valve receiving depressions; cup-shape valves each having a. circular rim portion facing the valve retainer plate and disposed to move into impinging engagement with the spring members to tension the same; said valve members each having a convex spherical contour portion intermediate the rim portion facing the valve receiving depressions and adapted to move thereinto, and having a Eoncave interior contour to receive the posts therein upon movement of the rim portion of the valve into impinging engagement with the spring members; a thin resilient valve seating and actuator plate disposed in juxtaposed relation to the surface of the supporting plate hav-, ing the depressions therein, said actuator plate projecting outwardly from the edges of the depressions to form resilient valve seats therein comprising annular circular openings for seating the convex spherical contour portions of the valve therein to close the inlet passages and resiliently tension the portion of the plate projecting from the periphery of the valve receiving depres-v sions to the circular opening.

WUNIBALD I. E. KAMM. WILLY F. KRAU'ITER. KURT STAIGER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 402,647 Beldam May 7, 1889 797,739 Meer Aug. 22, 1905 848,739 Gut Apr. 2, 1907 1,550,376 Longacre Aug. 18, 1925 1,568,195 Spreen Jan. 5, 1926 1,568,940 Dooley Jan. 5, 1926 1,651,235 Terrill Nov. 29, 1927 2,140,328 Mozier Dec. 13, 1,938 2,550,515 Anderson Apr. 14, 1951 2,581,902 Bodine, Jr .4 Jan. 3, 1952 2,605,109 Myers July 29, 1952 2,610,064 Goddard Sept. 9, 1952 FOREIGN PATENTS Number Country Date 374,124 France 1 Apr. 10, 1907 20,740. Great Britain Oct. 13, 1905 578,738 Great Britain July 10, 1946 OTHER REFERENCES Project Squid, Tech. Memo. No. Pr. -4- by Ing. Guenther. Diedrich, published June 30, 1948, by Princeton Univ. (pages 34 and 35, Fig. 46). V

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