Патент USA US2403569код для вставки
July 9, 1946» 'M_ wA-rTER FABRICATED METAL STRUCTURE Filed June 16, 1945 2,403,569 4 SÈeets-Sheet 1 _ ÍNVENTOR Michael Waiter“ BY ATTORNEY July 9, 1946. 2,403,569 l > M. wAT'rER FABRICAIED METAL STRUCTURE AFiled June 16, 1945 ì . ^ 4msheets-sheet 2 “Aman INVENToR Michael Waiter. ATTORNEY ` . July 9,'1'946. M, WATTER ` 2,403,569 > ' FABRICATED METAL STRUCTURE Filed June 16, 1943 4 Sheets-Sheet I5> y 60 INVÈNTOR f ‘Mic had Waiter 'PT July 9, 1946. 24,403,569 M. wA'rTx-:R' FABRICATED METAL STRUCTURE Filed June 16, 1943 4 sheets-sheet 4 Illllllllllllllllllllllllllllllll! Om., 0Emr. _ ` d.%.o@ INVENTOR Michaël Waiter. BY Í -ATTORNEY ‘ 2,403,569 UNITED STATE s PATENT -oFrlcE Patented July 9, 1946 2,403,569 p FABRICATEDA METAL STRUCTURE ' Michael _Watten Philadelphia, Pa., assigner to Company, Edward G. Budd- aManufacturing corporation of Pennsyl Philadelphia, Pa., vania ' Application June 16, 1943, SerialNo. 491,034 11 Claims. (.Cl. 244-124) » 1 This invention relates to fabricated metal of Fig. 8. structures, particularly to an improved construc tion and method of assembly _of airfoils. and has for an object the provision of improvements in‘ this art. ' El In the fabrication of skin-covered frame-sup ported structures, such as airfoils, from sheet metal, it is very desirable and economical to pre pare sub-assemblies, which include portions of the covering skin and 'associated parts, and to unite these sub-assemblies to form larger sub assemblies suitable for later forming unit groups. In this way the manufacturing operations may » . ` _ f ers, and rib elements, together with spar elements spar elements near the trailing edge. The parts faàëture and the most favorable inspection meth are so formed and arranged as to afford easy and . The primary object of the present invention is to provide a structure `of multi-part construc tion in which the parts comprising sub-assembly> 20 units are so arranged as to afford maximum facil ity for uniting such' parts as ribs, stringere, and the like to the skin- sheets, and the subsequent assembly and joinder of the sub-assembly units to form the completed unit. ' The invention is illustrated in connection with an airfoil for aircraft, as for example, a wing, aileron, 1in, rudder, stabilizer, elevator, or the like; and speciñcally a tail fin in one embodiment and a horizontal stabilizer fin in another. According to the present invention, the airfoil, certain forms of which are shown herein for the purpose of illustration, is made in mating parts such as half-shells which are later secured together to form a final assembly unit. Each near the nose or leading edge and provisions for workers to secure the greatest speed of manu . -2 parti-shell includes the skin, various skin stillen» be Widely divided` among the greatest number of o . view- of parts shown within the enclosed area Il ‘ Another object is that of providing sub-as sembly units, such as bi-partite units, in which rapid iinal assembly, as for example by ther use of spot welding tongs inserted from one open edge of the airfoil. ` Referring particularly to Figs. l and 4, the iin illustrated herein comprises aleading edge or nose section’ 29,' a. trailing section' 2|, a tip section 22, and a fuselage fairing section 23. The fairing section may be formed as a separate sub-unit which is attached later, hence the tail iin unit will be considered as a complete „sub-unit with‘- . out the fairing'- section. The fin includes a nose spar structure 25 and a rear spar structure 2li.4 These are both indicated by dotted lines in Fig. 1. assembly unit they afford a light Weight unit of 30k The nose spar structure is shown in Figs. 2 and great strength capable of efficiently »transferring 3, but the rear spar is omitted in Fig. 3because the various stresses encountered in use. it is convenient to insert this from the trailing the parts comprising the same are so related that when associated and assembled together in a iinal The above-mentioned and other objects and ad vantages of the invention will be apparent from edge after the half-shell sub-assemblies have been secured together. the following description of certain exemplary 3 e) As indicated for the full fin in Fig. i and as embodiments thereof which are illustrated in the accompanying drawings, wherein: Fig. 1 is a side elevation of an airplane tail iin y embodying the invention; _ shown for a representative portion of the iin in Fig. 4, the airioil includes the thin gauge metal skin 30 which is rigidiñed by parallel rib-like ele ments which may-be of the-same or diiîerent Fig. 2 is an enlarged horizontal section taken 40 types. As here shown, diiierent types of ribs are _ _ employed. There are small stiiîeners or formers on the line 2-2 of Fig. l; i Fig. 3 is a pre-assembly‘view of the‘parts shown in Fig. 2; . Fig. 4 is an enlarged partial vertical section taken on the line 4--4 of Fig. l ; ` Fig. 5 is an enlarged fragmentary perspective View of parts shown within the enclosed area 5 of Fig. 2; Fig. 6 is an enlarged vertical section of the fln tip taken on the line 6_6 of Fig. 1; Fig. 7 is an enlarged vertical section taken on the line 1--1 of Figs. 1 and 2;` . ' Fig. 10 is an enlarged section taken on the line ||l--|0ofFig.8; and ‘ployed `but as thisl is similar in principle to the other heavy ribs it need not be specifically illus trated or described herein. Since it is not en closed within the airfoil but is exposed at one end it may even be made as a single piece welded through outturned flanges to the assembly. ' Fig. 8 is a section similar to Fig. 2 but showing a modification in a horizontal-stabilizer fin; Fig. 9 is an enlarged section taken on the line 9-9 of Figs. 8 and 11; 3l, open truss ribs 32, and full-web ribs 33. Where the rudder hinge brackets- 35 are located the heavy full-web rib construction 33 is em ployed. At the base of the fin an especially 4 heavy bulkhead type of rib construction 35 is em . As shown in Fig. 1, the heavy ribs 32 rand 33 are continued into the nose portion 20 as rib elements 40. Referring also to Fig. 2, skin stiiîen ing stringers 4I, which are disposed transversely of the rib elements 40 are also provided in the nose section. At the leading edge of the nose Fig. 11 is an enlarged fragmentary perspective 60 section the skin 3D is bent to-form stringere 42 ‘ 3. 2,403,569 whose flanges extend forward for welding after the half-shells have otherwise been secured to gether. Of course, the strengthening and con necting elements 42 may be separate members 'attached to the skin, if desired. A nose skin sheet AThe webs 45a of the tip ribs 45 (Fig. 6) are similar to the webs 33a of the heavy ribs 33 and the same reference numerals are used'for their y parts, but the Abeads 64 and struts 66 may be omitted. They may be reinforced on their outer 43 is secured~ to the leading edges of the main edges by L-shaped stringers 60h which are welded skin sheets after the final assembly operation to thereto and to the skin. A reinforcing plate 45h conceal the stringers 42 and complete the airfoil is secured beneath one of the ribs 45. The skin ` contour of the finally assembled unit. may be made in sections which are connected As shown in Figs. 1 and 6, the ñn Vtip 22 is pro 10 by the plate 45h prior to assembly. _ vided with ribs 45 which are parallel to the ribs The nose spar 25 (Figs..2, 3, 5 and '1) comprises» 32, 33 of the main fin section 2|, which ribs 45 flanged channel chords 25a which are welded have full webs like the ribs 33. The tip is also through their backs tothe skin 3|), a strengthen provided with parallel skin stiffening formers or , ing plate 25h, if desired,_ being interposed between stringers 46 arranged parallel to the ribs 45. In 15 each channel member and the skin. The skin addition, the tip is provided -with-rib elements may be made in sections which are connected by 41 which extend at right angles to the ribs 45, 46. The rib elements 41 may be divided longitudi nally to avoid the ribs 45 and laterally to leave the plate 25h prior to assembly. The plates 25h are wider than the backs of the channel chords ' 25a and the adjacent rib webs are suitably joggled The skin may be 20 to receive the extended edges of the plate. A ~formed to provide nose stiiïening elements- 42 closure plate 14 is welded to the interior of each and the nose may be covered by a closure sheet l channel chord 25a and with it- in effect forms a 43, as above described for the leading edge. closed box spar chord on each side adjacent the open spaces in the center. A_s shown in Fig. 1, the fairing section 23 is skin which vincreases the torsional resistance of provided with ribs 43 which are parallel to and 25 the channel chords 25a. There is left inside each lpreferably aligned with the ribs` 32, 33 of the box chord thus formed a wider channel and at main ñn section 2|.` The fairing section also intervals therein there are secured cupped strut includes a heavy base rib or bulkhead 50 for elements 15 arrangedback to back and welded anchorage to the fuselage, as by bolts 5|. _At the, together through their overlapping portions in leading-edge it is provided with vertical stiiîen 30 the iinal assembly, as at 16. The spar -strut ele ing means 52 and at the rear with a spar element 53 which supplements the front spar 25 at the 1 lower end. The ,fairing section in fully assem- / bled condition is secured to the main iin assem ments 15 are preferably aligned with the adja cent rib element. The strut elements maybe secured to the plate 14 before the plate is welded to the channel member 25a; and the latter is bly by screws 54. 35 welded to the backing plate 25h and preferably As shown in Figs.. 2, 3 and 4,'_the full-webbed also to the skin before the inner plate 14 is welded ribs 3_3 are formed by flanged webs 33a which in. The side walls of the channel member 25a are welded to the skin at their outer edges, as are welded tothe end flanges 13 and 11 of adja along flanges 5|), and are welded together along cent rib elements 40V and 33a. As thus formed, their overlapping edges interiorly, as indicated 40 the _nose spar 25 is open between the ribs 32, 33 at 6|. 0n the inner edges the webs arev strength éned by c marginal ñanges 63. - to permit welding tongs to be'. inserted from the rear openside to secure the nose webs 40a and Intermediately l' they are strengthened by'longitudinal beads 64 and by ñanges `surrounding lightening openings the spar strut elements 15v together. The rear spar 25 includes a. web 19 and’cap , 65, (Fig. 5). Transversely the webs are stiil’ened 45 strips or chords 80 and 8| provided with rear byilanged hat-shaped struts 56 which are ar wardly extending flanges which may be welded ranged on opposite sides of the ~webs and have 4 to the skin after the spar is set into position. overlapping ends which are welded together when An interposed plate 82 on each side reinforces the webs are Joined along their overlapping edges. the skin and may serve to Join twol skin sections 'I'he open ribs 32 comprise flanged webs 32a 50 together. Edge stringere 83 may be secured to secured through outer flanges 60a' to the skin sheets‘30 vand marginally flanged interiorly as at 63a and interconnected at-intervals Vby hat ‘- section struts 35a' which are' spot welded thereto and which> overlap ’_each other and are spot welded ' the skin after the spar has been secured for the attachmentrof a rudder arch (not shown). In Figs. '8 to 1l a modification is shown. together, as at Ila, in the final assembly opera- ' tionfthe spacing of the struts 66d being some welded together as at _ |-6|. glglat’gomparable to that _of then struts 66 of the As shown in Figs. 2 and 3, ythe nose rib elements their front extended ends where‘ they are kwelded together, as indicated at 33.A The webs are pro vided with outer flanges 1l welded `to the skin ' , They are strength- ‘ ened by interior flanges I 63, transverse .beads |64, and Z-shaped stifi'eningstruts |66. The beads y 40 are Iformed of two webs 43a which overlap at 34, front end flanges 1|_also welded to the skin, Here the rib |33 4includes the webs |33a -which are provided with outer flanges |60 welded to the skin |30 and Í„inner overlapping portions which are and ribs are disposed on opposite sides for the respective webs so as to avoid obstructing ,the overlapping faces of the webs which are to ~be welded together. . . l The nose rib elements |40 comprise the webs |40a which overlap at the front end for welding, ^ ' interior flanges 12 in, their spaced-apart portions, - as at |69. ,The webs Illia, each includes an outer and rear flanges 13 which are welded tothe front flange |10, a front end' ?ange |1|, strengthening beads |12, and notches |13 lin the outer edge to spar chords 25. y The webs 41a of the vertical .ribs 41 of the tip receive the skin stiiïening stringere |4|. Nose (Fig. 6) aref very similar to the webs 44a of the 70 stringers |42 are Secured to the skin sheets and - nose edge ribs 30 .and their parts are designated after their forwardly exposed flanges 'are welded by the 'same reference numerals.- The supple together the space is covered by a closure sheet mental web elements 41h are hanged on all edges, |43. _ The nose section may be covered by sheets as by cupping, and are secured through their' | 30a which are non-integral witlî the main sheets outer iianges to the skin 33. j 15 |30 and are overlapped and welded theretoat «2,408,569 _ the spar, if desired. This construction is the one illustrated. either before or after the vmain assembiyis' vse ’ cured to the anchorage structure. The structure-shown in the modiiication of Figs. 8 to 11 is so similar to the first form that no special explanation of the method of fabri >flanged-channel or hat shape, as shown. , _The rib cation is needed. It may be noticed, however, webs |33a extend forwardly past the front spar _ that the second modiñcation makes it somewhat location and are recessed as at |34 to span the easier to assemble the nose section half-shells to chords |25a. Reinforcing gussets |31, suitably gether. A permissible variation in assembly pro flanged, are provided at the rib recesses |34. At cedure with either form, though requiring some . the front end, the webs |33a are provided with 10 special welding tools and varied procedure in the ilanges |11. Heavy channel-sectioned spar struts ñrst- form, is to secure the two nose half-shells |39 are welded to opposite sides of the respective together before they are secured to the main sec Spar chords |2511, are secured to the inner side of each skin cover. These members are of webs |330. at the front end, which struts are cut _ ` tion half-shells. ' - away at a bevel at the adjacent ends to permit It is thus seen that the invention provides an welding through the overlapping Webs in the final 15 improved airfoil lconstruction and an improved assembly operation. The characteristics of the structure hereby method of >fabricating the same, all leading to economy and speed of production thoroughness provided are such that the fabrication of the of inspection, and strength, lightness and de airfoil is greatly facilitated. Each half is formed pendability in use.` While spot welded connec-V in a contoured form-fitting jig which is a replica 20 tions have beenv shown throughout, it is to be of the shape of the corresponding part of the understood that riveted connections may be used final airfoil. For example, considering the first when desired. , ' embodiment of Figs. l. to '17, three skin sections ' While certain embodiments of- the~`invention are welded together through the plates 25h (Figs. have been described in detail for purposes of il 2, 3 and 5) and 45h (Fig. 6). An alternative step 25 lustration, it is to be understood that the inven ` here would- be to use a single sheet for each side ' tion may have various embodiments within the and to weld the plates to it, These skin assem limits of the prior art and the scope of the sub blies are placed in form-fitting jigs and the joined claims.` shaped skin formers 3|, 4| and 48 Welded in. What is claimed is: The channel chords 25a, are then welded in place. 30 1. _A metallic construction comprising in com The nose ribs 40, the main section ribs 32, 33 bination, two separately fabricated' parti-shells, and the tip ribs 45y 4l are welded in place, and ‘each including a covering skin, fore rib elements, the elements 40, 32, and 33 are welded to the channel chords 25a. Next the channel, closure plates 14 are welded into the widened space of the channelchords 25a. The spar struts 'l5 may ' have already been attached to the plates 14. At the outer edges they are welded with the closure plates to the outwardly and upwardly extending side iianges of the channel chords 25a. They are aligned with their correspondingr rib elements. The half-,shells arev placed -in a full airfoil jig, aft rib elements having a junction with the fore ' rib elements, transverse spar chords at the junc tion between the fore rib elements and -the aft rib elements, and spar connecting strut elements at thesaid junction, said rib elements and said spar strut- elements being aligned for each `rib -and the elements of the parti-shells being over lapped in therfinal assembly ‘and secured to gether through their overlapping portions by shear elements inside the skin-covered assembly thus- formed, the spar being open between its elements and between the ribs from one end gether. There is enough overlap in each rib and 45 strut to the other in the assembly to‘provicle access in the spar struts 'l5 to provide for this. The from the edge for connecting the fore rib ele parts to be welded together are all in alignment, ments, the spar strut elements and the aft rib hence it is easy to make the welds by welding elements, as by rib-straddling welding tongs tongs inserted from the open rear edge. Bent ` welding tongs are required for the tip ribs 41, so passed over an end of _a rib. 2. A metallic construction comprising in com but since these ribs are open behind the nose bination, two separately fabricated parti-shells _ ends, it is easy to insert the welding tongs from >each including a covering skin, nose ribs, >each the rear. including elements which overlap between their The flanges of the nose strirgers`42 are spot at their front ends and stand spacedapart welded together from outside the assembly. 55 planes at their rear ends when the ‘parti-shells are and when properly clamped in position the juxta posed overlapping rib elements are -welded to ' Thereafter, the nose skin sheetsdS are secured over the connected nose stringere. They may be secured wholly from the outside by screws en assembled, main rib elements which overlap be tween their planes along their length when the parti-shells are connected, transverse spar chords tered into'previously placed fittings or they may at the junction of the nose and main ribs which be welded on, as shown, working partly inside, 60' stand spaced apart when the parti-shells are since this is still open from the rear. The pro assembled, and spar connecting strutl elements aligned with s_aidrib elements which overlap be tween their planes when the parti-shellsv are being constructed. v assembled, the overlapping portions of said rib 65 The rear spar 26 is inserted and secured from elements and spar strut elements being con cedure may be varied in accordance with the relative chordal width of the particular airfoil the rear after the airfoíl has been assembled. The full width- of the rear end of the airfoil is thus left open for the insertion of tools until therear spar is brought in. The. »edge stiffeners 93, nected through their planes in the assembly. 3. AA metallic construction comprising in com may be placed before the rear spar, the skin being suñiciently flexible to permit the spar to be in ing spaced ribs each formed of .plateylike part ribs welded together through overlapping por bination, a nose section including spaced ribs formed of plate-likepart-ribs welded to the hinge brackets 35, and the arch may be placed 70 each gether through overlapping portions, and a metal later.' As an alternativa-the edge stiffeners 83 skin covering on said ribs; a main section includ serted past the stiffeners. The fairing section( 23 is _also introduced later, tions, and a metal skin covering on said main Y 2,403,569 section ribs; and a transverse spar between said `sections, said spar including spaced channel shaped chords secured lbetween adjacent front _ overlapping plate-like partsy secured together-_ `through their overlapping portions, and each part of each lmain rib element being secured at its leading end tothe adjacent stringerelement, and main part-ribs on each side at the skin cov-~ erings, and spaced spar struts formed of strut elements Welded together through overlapping portions, said struts and ribs being aligned chord Wise of the ribs and said spar being open between said struts, and the main‘ section being open fromi the trailing edge between the ribs, whereby the and a channelled` metallic member rigidly secured ' ` to each rib element part at the leading end thereof, said channelled members overlapping each other with and being secured together through said rib element parts and extending sub stantially between said opposed Stringer elements,V I the nose rib elements being secured to the stringe:` part-ribs and strut elements may be Welded to _ gether inside from the trailing edge. elements. 4. A metallic interiorly framed exterlorly cov ered structure, comprising in combination, chord « _ . ‘ 8. In an airfoil having a nose portion, a main portion, and a metallic Skin covering extending> over the opposite sides of said portions, a pair oi opposed spanwise -extending through-running Wise extending nose ribs and main ribs and a transverse spar between them, said sparl includ ing channel-shaped chord elements .or cap ~strips . channelled metallic Stringer elements secured to having in section a back and spaced sides and the inner surfaces of said covering, one at each an open front secured to the skins through their side between said nose and main portions, metal backs leaving their open fronts facing each other, 20 lic main rib elements extending chordwise from said chord elements having closing chordv plates over theirinner 'open fronts, and spar strut ele .said Stringer elements throughout substantially the chordwise extent of said main portion, said main rib elements each embodying overlapping ments secured to said chord plates of each chord element, said. strut elements being overlapped and secured together in the overlap. plate-like parts secured together through their ' - '_ . overlapping portions, and each part of -each'main rib element being secured at its leading end to the adjacent Stringer element, and a channelled _metallic member rigidly secured to eachrib ele ment part at the leading end thereof, said chan 5. A metallic interiorly framed exteriorly cov ered structure, comprising in combination, chord wise extending-nose ribs 'and main ribs and a mtransverse spar between them, said spar includ-v ing channel-shaped chord elements or cap strips 30 nelled members overlapping eachother with and ' having in section a back and spaced sides and being secured together-through said vribfelement an open front secured to the skins through their parts and extending substantially between said backs leaving their open fronts facing ,each other, said chord elements having closing chord plates opposed Stringer elements, the nose rib elements'A being secured to the Stringer ‘elements and to over their inner open fronts, and >spar strut ele 35 the main» rib element parts. ments secured to said chord plates of each chord y 9. A metallic structure comprising a ñrst and element, said strut elements being overlapped second ‘spaced covering skins and havingvat least __ and secured together in the overlap, said spar one open edge, laterally spaced rib members ex strut elements having their overlapping surfaces arranged transversely of the spar direction an parallel to the rib direction. » - tending in a first direction from said open edge .40 and Lsecured to the iirst of said skins, comple mentary spaced rib members extending from the second skinand each generally _paralleling itsÁ 6. In an airfoil‘having a nose portion, a, main portion, and a metallic skin covering extending „ corresponding first mentioned rib member, means over the opposite sides of said portions, a pair of connecting said rib members, said means in opposed spanwi'se ' extending through-running 45 cluding elements overlapping in planes parallel channelled metallic stringer elements secured to to said rib elements, a spar member secured to the inner surfaces of said covering, one at each theiìrst skin and extending in a direction trans side'between said nose andmain portions, me tallic main rib elements extending chordwise from said Stringer elements throughout substan tially the~ chordwise extent of said main portion, verse to the first direction, a complementary v 50 f spar member secured to the second skin and ex- . ~tending generally parallel to the ñrst spar mem ber, means connecting saidspar members, said last-mentioned means. including' elements over-_ lapping in planes parallel to said rib elements, their overlapping portions, and >each part of each main rib element being secured at its leading end 55 whereby the _overlapping elements of the rib member connectingvmeans and the overlapping to the adjacent Stringer element," and a chan elements of the spar member connecting means nelled metallic member rigidly secured to each are disposed in parallelism sc_as to be readily rib element part at the leading end thereof, said channelled members overlapping each other- with v secured together through said open edge of the and being secured together through said rib ele 60 said main rib elements each embodying overlap ling plate-like parts secured _together through structure. ment parts and extending substantially between said opposed »Stringer elements. , '7. In an airfoil having a nose portion, a main 4 , _ portion, and a metallic skin >covering extending apart suf?ciently along the length of the spar over the opposite sides of said portions, a. pair of ,65 members to provide working access between them. opposed spanwise extending through-running 11. A metallic structure as set forth in claim channelled metallic Stringer elements secured to 91 which includes rib members on both sides of ` . the inner surfaces of» said covering, one at each the spar members, said connecting .elements of side between said noseand main portions, me; the _spar members being spaced apart suñlciently tallic main rib elements extending chordwise 70 along the length of the spar members to provide Afrom said Stringer elements throughout sub working access between them. stantially the chordwise extent of said main por tion, _said main rib elements 'each embodying _ 10. A' metallic structure as set vforth in claim i 9 further characterized by the fact that the con hecting elements of the spar members are spaced 'menant wanna.