1946.10.29 -- fresco wing patent

8/3/2019 1946.10.29 -- Fresco Wing Patent

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Oct. 29, 1946. s, FRESCOV AR IA BL E C AM BE R W IN G-Filed Jan. 11, 1945

2,410,0562 Sheets-sheet 1


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Oct~29, 1946. J. FRESCO 2,410,056V AR IAB LE CA MBER W INGFiled Jan. 11, 1945 2 Sheets-Shee~ 2

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Patented Oct. 29,) 946 2 , 4 1 0 , 0 5 6

UNITED STATES OFFICEATENT2;410,056

VARUBLE CAMBER WING.Jacque Fresco. HoIIY:wood. Calif.

AppUcation JanulI,ryl l, 19


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3to the cylinder 3. The source of fluid pressureto the conduits 13.and 14may be, for example,a hand operated pump and valve mechanism (notshown) whereby fiuid may be pumped into thecylinder 3 on either side of the piston 4 and 5trapped therein so that the hub member 1maybe shifted any desirable amount relative to .hubmember 10to vary the wing airfoijsection thick-ness ratio as well as the area of the wing in amanner which will now be described. 10Referring again to Fig. 1, it is seen that the hubmember 1has connected therewith a plurality of ..angularly disposed spar members,. respectively,Indicated by reference numerals 15 to 24, inclu-sive, and the spar member 20 being disposed in 15the plane of the maximum thickness of the.alr-.foil sections of the wing and 'being subdivided orbranched into further spar members ,25,to 28,inclusive. The hUh. structure 2 is positioned inthe plane of symmetry and at the. point of maxi- 20mum thickness of the root chord of the wing, andthe .spars Hi to 24, inclusive, are formed at theirinner ends as. u-shaped-caannel members eachterminating in an end wall 30 secured by meansof bolts 31 or the like (see Figs. 2 and 3) to the 25flange 8 of the hub member 1. The sparmem-hers, while rigid adjacent their points of connec-tion to the hub member 1 ., have a section suchasIndtcated in Fig. 4, outwardly thereof to pro-vide a considerable degree of resilience. 30As will be noted' inFig. 1, the spar members t 5to 2-ll,nclusive,define the upper boundary surfaceo f the wingstructure,and similarly companionspars are positioned in the lower .boundary sur-face of the wing and indicated by the same refer- 35ence numerals with the subscript "a" appendedthereto. The spar members lying in the underboundary surface of'the wing cooperate with cor-responding spar members in the.' upper surfaceto form related pairs of spars which are integrally 40or .otherwise connected at their outer ends andthe spars ISa to 24a, mclustve, are all secured attheir inner ends by means of bolts 32which passthrough the 'ends walls 30aand the flange II ofthe lower hub member 10(see Fig. 2). The lowerspar member 20a is branched into branches 25 ato 2Sa in the same manner as the upper sparmember 21), the branched spar members alsoforming related pairs. It wlllbe seen, by refer-enceto Fig..1, that the spar members lying inthe upper and lower boundary ,surfaces of thewing and extending angularly from the hubmembers 1and 10define a wing structure withoutthe use of conventional rib members, with the'exception that the terminal portions of spars 20'and 2!la and branch .spar members 26 to 21 and25a to 28ahave their terminal. portions rigidlyinterconnected bymeans of a transverse rib mem-ber 35 which also serves as an anchorage or sup-port; for a conventional rotatable tip aileron 36.A .flexible leading edge 37 tapered in thicknessis secured to those pairs of spar members whoseterminal ends extend to the forward marginalboundary of the wings, the leading edge beingllreferably secured so as to allow the nose portionto expand and contract. In a similar manner atapered trailing' edge portion of flexible material38 is secured to the terminal portions of those"related pairs of spars which extend to the rearmarginal boundary of the wing.It will be readily understood by reference to

Fig. 1hat the spars in the upper and lowerboundary surfaces of the wing, being flexible overatleast their outer portions, will permit the upperand lower boundaries of the wing to be moved

2,410,056 4relative to each other hymovement oLthepiston4,Fig. 2, in, the cylinder 3. As the piston 4movesupward the maximum thickness of any transverseairfoil section- through the wing will be increasedand simultaneously the chord of such a sectionwill be decreased so that the ratio of thicknessto chord will be increased, {see also Fig, 5) andconversely a downward movement of the piston 4within the cylinder 3, Fig. 2,wilI cause a decreasein thickness ratio and an increase. in 'the wingchord at any transverse section (see also Fig. 6)so that the wing area as well as the thicknessratio will be simultaneously varied. Itwill benoted that substantially all areas in the boundarylength of any spar between the leading and trail-ing edges will remain constant and variations inlength willoccur mainly at the connection of therelated pairs of spars at the leading and trailingedges. ACcordingly, the wing may be coveredbetween the leading and trailing edges with thinsheet metal, doped fabric or 'suitable plasticma-tertaisecured to the spar members by .rivets, wirestitching, or the like. It is essential that theleading and trailing edges ,3 1 and 38 be made orflexible material and suitably locally stiffened bycorrugations, or the [ike, to resist shear failure.OperationIt will be readily. understood by reference toFigure 1hat movement of the hub memoersjand I0 relative to-each other caused by fluid pres-sure acting on piston ,4will cause the spar mem-

bers to yield resultingJnan increase oridecreasein airfoil section thickness in a manner previouslydescribed. Since"by increasing the thicknessratio. of an airfoil section, its lift coefficient maybe. increased. in nearly direct .proportion to theincrease in thickness, it is possible to create ahigh lift for takeoff and landing with an aircraftconstructed in accordance \viththe inventionmerely by' the pilot admitting fluid under pres-sure to conduit 14,Fig. 2, to move the piston 4upward, and once the aircraft is in the airfiuldmay be drained by the cylinder 3 from the under-45side of the piston 4 and fluid admitted underpressure through 'conduit! 3to the upper side ofpiston 4 so that the wing thickness ratio will bedecreased, causing a decrease in Hftcoefficientas well as drag .coefficient to obtain the most50 favorable airfoil characteristics for high speedflight. It will be readiJYunderstood that by trap-.ping fluid in the' cylinder 3,the. piston 4 maybeeffectively locked at any point in its permissiblerange of movement so that the variation in thick-55 ness ratio and corresponding change in area, ofthe wing is under control of the pilot at .alltimes,and aerodynamic forces acting on the wing cannot have any detrimental action: It is to beunderstood that the invention contemplates any60 suitable means to perform the equivalent func-tion of the hydraulic jack structure includingcylinder 3 and piston 4, illustrated in Figs. 1and2, such as, for example,a mechanical screw jackmanually or power actuated which would readily65.serve the' same 'function. "It'Willbe readily seen that the spar arrange-ment in the wing ,of Fig. 1 is such that the' airloads transmitted to the spars from the wingcovering, not shown, wiUin each :instance be70 transmitted along the spars to the point ormaxi-mum camber at the root chord sothatthe struc-ture in accordance with the invention gives riseto the desirable 'stress transmission previouslydescribed. It should also be understood that75while the wing structure of Fig. 1s illustrated


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5 62,410,056as.being of variable camber; variable area type, foil crosssectioncomprisinga plura1ityofflexiblethat these latter named functions may be dis- spar members angularly disposedwith respect topensen with and the spars arranged as a rigid each other and respectively lying in the upperframework. In such a case, the spars may have and lower boundary surfaces of the wing .struc-their upper and lower edges defining the upper 5 ture, spaced upper andlower hub members,con-and lowerboundary surfacesof the wing. It will nections betweensaid sparsand a respectivehubbeobviouswithsuchan arrangement that a con- member, the terminal ends of said spars extend-ventional tYPeaileron may be employedin lieu ing to the marginal edges of the wing structureof the tip aileronsuchasil1ustrated inFig. L and upper and lower spars being connected atWhileone formof the inventionhas beenIllus- 10 their terminal ends to form related pairs,flexibletrated and described, other modifications and leading and trailing edgesconnecting the termi-variations thereof will becomeapparent to.those nal portions of certain of said pairs of spars andskilled in the art as falling .withinthe scope of means for movingsaid hub members relative tothe invention as definedin the appendedclaims. each other. to thereby vary the thickness ratioI claim: 15 and chord length of the airfoil cross sections of1. An airplane wingconstruction of doublesur- the Wing.face airfoilcrosssectioncomprisinga central hub 5. The structure asclaimedinclaim4, inwhichstructure positioned in the plane and substan- certain ofsaid spar members are subdividedintotially at the point of maximum.camber of the .branches angularlydisposed with.respect to eachroot chord,a plurality of sets of angularly dis- 20 other. ....posed spars connected to said hub member and 6. Thestructure as claimedin claim4,in whichextending radially, one set lying in. the upper one of said related pairs of spars extends fromboundary surface of the wing and the other set the root chordin the Plane of maximum camberlying in the lowerboundary surface of the wing, of the airfoil sections and each spar of said pairand means connecting the terminal end ofeach 25 being subdividedinto branches extending to thespar inoneset to the terminal end of a respective leading and trailing. edges respectively.spar in the other set to form related pairs and 7. The structure as claimedin claim4,in whichalso connecting said pairs to each Other, the the means for movingsaidhub members relativeterminal ends of said pairs of spars lying in the to each other comprisesa fluidpressure actuatedmarginal boundaries of the wingbetweenthe tip 30 jack.and root chordsections. . 8. In a tapered double-surfaced airplane wing2. The structure as claimed in claim 1, in construction, a central anchorage meanspost ...whichat least certainof the spars of each set are tioned at the point of maximum camber of thesubdividedintobranched spar elementsangularty root chord, radially. extending spar membersdisposedwithrespectto eachother. . 35 secured at one end thereof to said anchorage3. The structure as claimedin claim1,inwhich means and angularly disposed with respect toeach of said spars is flexiblethroughout at least each other and defining the upper and lowerthe outer portion of its length, a flexibleleading boundary surfaces of the wing, a leadiIlg edgeedgeconnectedto the terminal portions of certain secured to the free. ends of certain of said sparsof said related pairs of spars and a flexibletrail- 40 and a trailing edgesecured to other of said sparing edge connected to the terminal portions of members.other of said related pairs of spars, said hub 9. The structure as claimedin claimB,inwhichstructure Including two relatively movable parts one of said.spar members extends from said an-to which said sets of spars are respectively con- choragemeans to the wing tip in the plane ofnected and means for moving said hub parts to 45maximumcamber of the airfoil crosssections ofsimultaneously vary the thickness ratio of the the wing, and angularly disposed branch spar .airfoil sectionsof the wingand the projected area members secured to said last-named spar mem,ofthewing. bel'.4.:A variable camber variable area airplanetapered Wingconstruction of doublesurface a1r- 50 JACQUE FRESCO.

1946.10.29 -- fresco wing patent

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