US2584298A - Antistall mechanism for airplanes - Google Patents

Description

Feb. 5, 1952 J, l. 53E/.w7 JR 2,584,298

ANTISTALL MECHANISM FOR AIRPLANES Filed sept. 25', 1947 2 SHEETS--SHEET l JAMES I SEAY JR.

Patented Feb. 5, 1952 l ANTIS'EAEL MEGHANISM'FOE AIR'IIiA-.N-ES:`

JamesfLSm-r Mempheieimr Application Segtemb'cr 23, 13417,I Sei'aNQ; 7753582 seam.; wl-,ize-.Jei- E. Y l

'-Eljrisnvenon relates to-.devicesfor automaigi.- arr amount where the power of the. planeis. oalbammimizing; stalling inv airplanes; andfpan.- sui'ci'ent to cause. the speed-of the plane; to; Dik t ulaxly-flelatesyto aLdge-Vicein. which bheiloss of up., or` to-eausefohe plane` 1:0 diveangi pickA up li-gjsvinggpower `of the.: air flowngffoyeran airplane speeds. Winge, whenv theplane slows; doiifriin. ighiggbelow Q Thev meansV through which the foregoingand DALORQLSPWQ, aQLlll'LQS;Ielftglmehanisms Oprr otherr obects are accomplished; and the manner @plm-eguale@ tothe., elenatgrs'ofihe paneftode: of# accomplishment, will readilyV be,- understood Qressf the; eeyatprs andcause the planete. dive from the following specication n reference to and reefstalzilsh'.p1'o1;\.e1=,` speed'. f the accompanying drawing in which:

A irpglanegigligigntgare nel@unbyzthe-airzqw: w Fig; 1* ifseperspectvevewof a single nlotored mg Dalzver andunder the win-gs; some. two: pia/neindicating*positioningo'theicontrols.alone tliipgse the.L l'tng poweryo the, ain being exe the Wings@ 4 Q rteqlihrough ,vacuum ationion, theuppersur-f Figi` 2# is a diagrammatic Viewv sI-iovringY the ace m tpewings; and; the. ba1an;ceby,v pressure mechanism nnactvefposition, the View include @QtQne Everyg nleneihas en ;ajn sneedbelcwfwhh 15 ing. aLdi-agrammatic.crossesection offawingntiie Lioh Slgdwhn. the, planefis; in Eig. 351s asimilar. view showlng thefact-ion of ViaIQUSlSG SQL. 1199.135!!Y ai'lfmiltllg; to: Glmb the'mechanism". responsive. to a, drop in lift..

te@ by Sharp, banking, orfin leveliignteby Fgf. 4v 's-anenianged,dagxammatie View oitlfi@ .engine i ,ilmes f 20 con-trol valvesfandcactuating mechanism with the 'Ijhekpilg of me; plane ist often* unaware @ai pressure;vaweciosedgascin'Eigs. 2 and 6 trl. nlr-aneliaeslowed; clown. untlriheplane Fig; me@ smrnimflyl diagrammatic View with SQ Qlll 195.? 951mm@ @n it iS. 1290 Laie to make the pressure valve open as in Fig. 3.; and.-

GQ., geilen. Sauley hir-.n eli` and; theplaner and g 611s a vdiagrari;matic, v .iew snewinethe .Qon-

^ iliizlliif;` frantieeqrte to, makeacorireciien, i wor mechanism connecte@ for actuatien @been after-.benkngrmienne-mene;in c wings tnefmecnanisni neingiinfinoperaqiye nQf Pel-led when. he, wishes;4 c. moved toright or left in banking, witk1 F s latter @i the stiekeme t .meerawmgwf in; whicnvari.-

' echar-lim nel ed mi wenn, is rlQ,.QQ n. 1

Tee-@tick is; 59.7111,1ecief1,` infrange. numerals: lo and l2 are the wings of plane,

ageuSpaHy cahlesr in desired mannenwth el i ann; Ulu-5tneeieyatersn H y and, i8.. infin vato 's located inthe.- tail or the plane The one ings 1am-Quell" the/upper;- elfeceezoethe Wiegel@ were movementofethezsticlwepres s the eeV n meseopenings-beine;meier# veters.; causingthe t, il to lift4 and, i the pleine v te dive,- V

'lhobje'ctls of thelpreseniinvention are, pri,-V man y, 'QQ canse these elevators to be autgmeiiel- 1y depressed' andtheb plane t0 dive Whenever the, lift-ofthe Wings decreases below the lamount-necessary to sustairrthe pla-ne irl-the air;

'I'e-providemeansfresponsive tothe'decreasefin ig Wgr, c vacuum on theupper side -of the-wingsihrougfn mgigsa! 2 new? chepeping lieadsintga which depression ofthefelevatorsisaccemplished'; Collapsible 'bellows 20 wmh vis' ngi-m3411515; 5;-, and Y i f f neemt may be. extnded To provide mechanism responsiveto;=a.p1`.eser v vg;V 2J; anais collapsedby .Q fgzhllf@ *l'WZlSO 1 ci ngQ/fiilghiiof the alia-file Q` The lrcarries eQQntelf .4

believe7 .c with, an imminente/cit.- 2,6199

during flight. Leads 28 and 30 extend from the contacts 24 and 26 to an electrical unit 32 which may be a solenoid. This unit is operatively coupled as through links 34 and 36 to a pressure valve 38 and a drain valve 40 for concurrent closing of the one and opening of the other when the bellows is collapsed, and, when the bellows is extended and the unit deenergized, allowing a spring 4I to open the drain Avalve 40 and close the pressure valve 38.

The circuit is energized by an available energy source as a battery 42.

The pressure valve 38 is connected by a pipe 44 with a source of hydraulicv energy such as is usually available on planes and is notA here 4 Figs. 2 and 3, or to open the circuit of the type shown in Fig. 6. The linkage coupling the electrical unit 32 to the valves 38 and 40 in either case holds the pressure valve 38 open and the drain valve 40 closed and through the cylinder-piston assembly SII-56, and the bell crank arm '1D forces the stick forward and holds the elevators I4 depressed unless the pilot by sufcient pull overcomes the pressure ofthe piston on the stick and pulls it back, and so. long as this condition exists keeps him fully advised that there is insuiiicient lift to get off the runway and that it is inadvisable for him to try to start to climb.'l Whengthe plane reaches the speed at shown, and the valve 40 through a pipe 46' to overflow either into the reservoir ofthe hydraulic system or elsewhere. Both valves are connected through pipes 48 and 56 and a joint pipe 52 into a cylinder 54 in which is mounted a piston 56. The cylinder is provided above the piston and adjacent its upper end with an air vent 58 permitting unrestraining upward and downward movement of the piston, and with the pressure valve 38 closed and the overiiow valve 40 open is freely movable. From the piston, a piston rod 60 projects through the top of the cylinder and is guided thereby no stuiiing box is being needed.

62 is the usual control stick of the plane, which is connected in usual manner to the control surfaces of the plane. these surfaces including the elevators I4, which are connected to the'stick as by cables 66 and 68, and respectively depress the elevators when the stick is pushed forward and raise them when the stick is pulled back. The central stick is provided with a bell crank arm 16 which projects laterally therefrom. The cylinder 54 is positioned and rigidly supportedwith the upper end of the piston rod 60 spaced sufficiently below the arm, to allow the stick to be manually retracted and the elevators raise during flight.

In Fig. 6 operating bellows 20A and 20B. having the openings I6 and I8 respectively thereinto, are located in" the opposite wings of the plane, as indicated by the openings I6 and I8 of Fig. l. The bellows respectively carry contacts 24A and 24BA which cooperate with fixed contacts 26A and 26B, and are connected through joint leads 26A, 36A, to the electrical unit 32. The bellows carried and ixed contacts are held in contact when the bellows are extended, and are spaced apart in night by vacuum collapse of the bellows.

The unenergized unit 32 is coupled through links 34, 36 to the closedpressure valve 38 and open drain valve 40 in such manner that energization will open the pressure valve 38 Iand close the drain valve 40, as did the unit 32 and linkage 34, 36. when the unit 32 was deenergized. The contacts in the dual type of Fig. 6 must be open during normal flight of the plane so that closure of either will complete the circuit. In Figs. 2 and 3 a circuit which is closed during normal flight is shown but in that form it will be clearly seen that the open type of circuit might as readily be employed if desired.

When the plane is taxiing along the ground and until it picks up flight speed there is insuiicient lift on the upper and under surfaces of the wings to lift the plane clear of the runway, and the vacuum along the upper surface of thewing is insufficient to collapse the bellows 20 or 20A to close the'circuit of the type shown in which the lift is sufficient to raise the plane, the air flowing over the top of the wing, or wings,

exhausts air throughthe opening I6 or the openings I6 and I8 and collapses the bellows 20 and 20A, closing the contacts 24 and 26 of Fig. 2 or opening the contacts 24A, 26A of Fig. 6, setting up in Fig. 2, a circuit from the energy source 42 through the leads 28 and 30 to the electrical unit 32 energizing this unit, or in Fig. 6 opening the circuit to deenergize the unit, in either case closing the supply-,valve 38 and opening the drain valve 40 thus cutting off hydraulic flow into the cylinder 54 below the piston and allowing the fluid in the cylinder to drain out and freeing the piston to drop and release pressure on the stick. Subsequently, so long as iiow of air over the wings exerts the normal lifting vacuum on the upper surfaces of the wings and within the bellows, no action of the piston takes place, and control of the stick by the pilot is in no way hampered. However, should the speed of the plane in flight be reduced to an extent where-there is insufcient lift, exhaust action within the bellows is decreased and the resiliency of the bellowsA or the action of the spring 22 again extends the bellows, opening the contacts 24 and 26, Fig. 3, and deenergizing the electrical unit 32, and through the links 34 and 36 opens-the pressure valve 38 and concurrently closes the drain valve 40, allowing' the hydraulic fluid to flow into the cylinder 54, raise the piston 56, and force the stick 62 forward depressing the elevators and causing the plane to dive and pick up speed or reducing the elevator lift in climbing so that the speed may pick up under the available engine power, and continue to thus hold the stick and elevators until the speed of theV plane again picks up.

In the form of the device shownfin Fig. 6 de'- crease in speed as before decreases vacuumaction, allowing extension of the bellows. This action,however, closes the contacts'24A, 26A and energizes the electrical unit 32A and by direct action through the linkages 34, 36 opens the pressure valve 38 and closes the 'drain valve 40 accompushing the actuation of the suck s2 and releases this action by opening of the circuit. In certain cases as a side slip, or if for` other reasons, as in banking, the fuselage blanks air flow acr'oss a portion of one wing, vacuum on that wing becomes insufficient to maintain collapse of the related bellows either 2IIA or 20B, as the case might be, and the contacts carried by the released and extended bellows close the circuit and eifect the desired action.v It will be understood that the detail shown and described is illustrative only and may'bevaried from without departing from the'intent -anfcl dis'- closure of my invention, and-shall not be read into any claim unless specificallythereinset'v out."

I claim: I

1. In an airplane having Wings, elevator means depressible to cause Said plane to dive, manual means for operatingsaid elevator means, antistall means carried by said plane, including control means responsive to air flow, carried by at least one ofsaid wings, and elevator depressing means responsive to said control means; said depressing means including a cylinder, a. piston therein having a protruding rod extending toward actuating contact with, but not coupled to said elevator operating means, a source of hydraulic pressure, a feed pipe connecting said source and said cylinder, said Vpipe including a normally closed cut off valve, a drain pipe leading from said cylinder and including a normally open drain valve, linkage coupling said valves and compelling concurrentl action thereof, means operatively responsive to said control means, including a spring and an oppositely acting solenoid coupled to said linkage, a source of electric energy and circuits, each circuit including circuit completing contacts, one of said contacts in each circuit, being carried by said control means whereby to interconnect said energy source and said solenoid, for opening said cut oil valve and closing said drain valve on decrease of said air ow below a plane supporting speed and advancing said piston rod into elevator-depressing-contact with said elevator operating means, and for closing said pressure valve and opening said drain valve to release said depressing action, on restablishing of said air flow.

2. Elevator depressing means in accordance with claim 1 in which said circuit is normally an open circuit and is closed by action of said control means, and said feedand drain valves are respectively opened and closed by energization of said solenoid, and oppositely actuated by said spring de-energization of said solenoid.

3. Elevator depressing means in accordance with claim 1 in which said circuit is normally a closed circuit and is opened by action of said control means, and said feed and drain valves are respectively opened and closed by action of said spring on de-energization of said solenoid and oppositely actuated by energization thereof.

. JAMES I. SEAY. Jn.

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

UNITED STATES PATENTS Great Britain June 24, 1926

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