Document
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. - UTlGS 3 Sheets-Sheet z Filed Nov. 1 0 , 1354 I P- I , , ‘ 1 , !
j - , m r-- %SELL L. HOPPING W S L L 1 W R. FORLtFER ROBERT P GASTON, JR.
- -- INVENTORS i t I !
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I ' 3995,708
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8 ) which is mmnted on the exterior surface of the Bight pawl 76 has a bifurcated end 79 which receives the end A cylinder 1 7 is slidably disposed within of the pawl 77 i n a pivot connecfhn effected by a pin vebicle 11.
cfo. A compressed spring 82 is %Cui& as by welding, thc hocising 15 and carries a tonthed rack 19 yhich sljdes n e trailing if desimd, between the ends of the pawls opposite tbe within a groove 21 farmed in the housing.
5 pin %I thereby urging the ends outwardiy against the sides end of the cylinder 1 1 7 i s cbsed Sy a plug 23 which has A c a p 29 of the groove 22. %%en the sVut extends a pmwt a socket 2 5 therein fur receivirg a spring Z'f.
fits over the eird of 2be spriog 27 a& compresses against predetezmined &staxe the spring-bed& pawls 76 a d 17 a piston 77 expmd into recesses 82 located on o p p d sides id the a retainicg ring 3 1 . Witah fhe qlinder 33 is telescopically arraased a d , SormaBy, the grezter groove 2 1 . l'hk stops extension of &e cygnder 1 7 , lav- poniun 6f its ]en& extends beyend the lesding ead of 10 ing it free to retract, however, s i c e the pawls ' 7 6 and the cylinder 17, The dis'al or iree and cf &e piistc'n 33 71 will be cammed out o f the recesses 82 upon retract- is provided with a plug 33 hAving an al;eiwe 36 througb b g moverneat o f the cylinder.
A foot 37 mmpricRs a tubufar ex- An enclosure 83 is providcd inside o f the blight vi?- the center thereof.
h i l e 1 1 . in alignmat with the cylinder 1 7 . The e n c b tension 39 which slips over the end of the piston 33 and fie plug 3 5 . The foot 37 hzs an e&irged fiaring p r i i o n 15 sure comprises a panel S7 having iQtega1ribs 89 which Side 41 which provides a convex wu$ars for making initial abut the inside s f the flight vehicle skh panel.
waUs 91 and an end box rib 93 are arranged around contact with the l a d i n g suriaee.
such as the panel 87.
A crushable energy-absorhiq material 45, metallic honeycomb, is p r M & whhin the foot 37 azd Within the enc:osure 9 is a locking pawl 95 pivotally bears on the plug 35. Apertures 47 and 49 formed i n 20 connected to a pin 97 which extends traasverstly of the the center of the foot 37 and crushbiz material 45, re- enclosure 83. In i t s focking position the 10cl;ing pawl spectively, are in alignment with each other and with 95 engages the toothed rack 19 through a slot 99 extend- A plunger 51 extends ing through the bottom of the groove 21 and the exterior the aperture 36 in the pleg 3 5 .
The plunger 5I also skin panel of the flight vehicle. The pawl is biased through each of these apertures.
extends through and actuates a pyssure swikh 53 which 25 toward 2 s locking position by a plonger 101 which is i s mounted on the inside of the plug 35 in alignment with urged outwardly by a spring 103 contained witbin a cyl- The switches 33 in Lhe sevzral struts a= k d e r 105. n e locking and udocking function ~ i : the the apertirre 3 6 .
electrieaily interconnected through wires 54 in a circuit pawl 95 k s controlled by an electrically operated devise 107 such as a solesoid or an electrical exploding device described hereinafter, The end of the piston 33 within the cyyiimikr I? is 30 which when energized releases a connection 109 be- Between this end of the tween the device 107 a3d an extensian Ill of the pawl provided with an end cap 57.
The connection 239 holds +he pawl 95 in its unlock- pistun 33 and the plug 23, the cylinder 1 7 contains an 95.
energy absorber which may be in the forin of a crushable ing position and when it is released the pawl is urged A pneumatic, into its locking position by the spring-urged plunger 101.
material 61 such as mstalfic honeycomb.
hydratiiic or contbinafion energy absorber a l w may be 35 Electrical connecths to the device lii? are made through used, particularly w h g e a reusable strnt i s required. an aperture 113 formed in the enc1osu:e panel 8 7 .
The end of the crushable material 61 adjacent the end It is understood that the locking p w l 95 is used to cap 57 is tapered inwardly at 62 so as to Trovide a stop retraction of the cylinder 17 at the desired position i proper onset rate of development of the ENshkg load within the support housing 1 5 . Hovfeser, when thw re- (decelerating force) when the piston 33 slides within 40 traction of the cylinder 17 is pre-.dent& by the locking To prevent pawl 95, the cylhder can still be extended wiaout dis- the cylinder 17, as explained, hereinafter.
the piston 33 from slidbg out of the cylindr 17 the por- engaging the pawl from the toothed rack 19 if sufficient tion of the piston within the cylinder has an enlarged diam- extending force i s appEed to the cyiiadcr to cause the eter forming a shoulder 63 which bears 02 a retainer slanting swfaces of the toofhed rack to slide over the 45 pawl against tbe bias o f the spring 103. his extending ring C4 sciewed iinnto the end of the cylinder- A hollow suppor~fairing 65 is rnountd on the Right force for postfanding prec:se kvefing of the vehicle may vehicle XL in tbe sliding path o f the cylineoer 1 7 . When be furnished by a jack 1x5 mounted witbin the enclosure the strut 13 is fully retracted, as in FIGURE 3, the plug 83. Tbe jack 115 may be electrically operated and am- 23 at the trailing end of the cylinder 17 abuts fittingly pribes a pivotally mounted pawl 117 for engaging &$ against the support fairing 65. The support fairing 65 toothed iack 19- Engagement of the pawl i 1 1 7 may be bas a slanting configuration 67 which coincides with a effected by a spring-loaded plunger 1x9 which is elcc- slanting configuration 69 of th? plug 23 i~ provide a trical:y released after rhe landing operation end energy continuous tapered surface from the cyfimkr 17 to the absorption cycle is complete. Any se'fected landing strut surface. of the flight vekicle 11. XnEntegmi w-3.h &e h o w 65 13 may be extended for vehicle leveling by an electrical h g 15 i s a channel-shaped element 70 forming an ex- linear motor 121 which drives the engzged jack 115 back tension of the groove 21 from the h a g a g 15 to the sup- and forth on track roaS 123 through a rack 12% E l e c - port fairing 55. trical oonaections t o &e motor 321 are ;lade through an opening 1 % in the yaad 87. T h e stioh of jack 115 is Meunted on the support fairkg 65 in axial alignment -When sufftcent to drive the toothed rack 1 9 rocking pawl wiLh the spring socket 25 i s a tapered skid 71- the strut 13 is fuUy retracted, as shown in FiGIIRE 3, the 95 a distance of one tooth kngth such b r pawl 95 loch s%ud 71 p r o + : & into the spring socket 25 resulting in the rack on a sucessive tooth for ea& stroke of the jack a crmpression of the sprhg 27. 315. Thus, the c r e w members may acmmpEsh precise The strat 13 is locked in its retracted position by a veEcIe leveling by selectively extedinp any ]=ding pin 73 which move$ in and out of a socket 75 k the 65 strut o r struts tu) by a &stance o f one hckhg r2& trailing end o f the tcrolhsd rack 1 9 . Ibe pin 73 may tooth length at a h e .
i;p, electrically aciuak3 as by'a solenoia 74 mounted The c i r c u i t o f ~ G b j 9 has a power sour& 127 far ?vi&&&waI o f the pin 73 from a circuit containing fQnr branches connected h parallel.
inside Uip. Bight vehjcie.
the smka 75 releases %e strnt 13 for a m i o n hod= E 3 & h n c l i iadudes the &tdi 53 & &e SOkQOid 207 &e w m p w spring fl pA/or 70 for each of two diame@iiwy o w struts 3 . 3 . Siicx fern proyjtks fie switches ana sofernid- from t b ~ oppxite strups a* wvitJ.- &&d by spbg-loaded series connected i n CF- btanck of the circuit, b& meenS&z of the stmt 13 and %f (w: ~ G U W 7) which a m s~mted mltches 53 must rkfie before current sows in the branch in a dot 3% extending transversely thrmgli &e Wotlxd to eaerghe the deaoids Jro? and punit the fwking fa~k Z9 near the trailiog ea8 cf &ha cylinder 27. The 75 pawis to 'engage tbe *wt&ed rack 119, 3,295,798
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tbe sco?e of &e a p w d e d c l a h s the invfntkn may b Operacon o f the invcndve landing gear system i s as practiced other than as spz&~afly described.
fol?ows: Woat is claimsd is: When the flight vehicle 3 f i s in flight the stmute 3 1 3 I. An energy-absorbirag device comprising: are stowed in the retracted positim shown in FIGURE ;a).a suppx-t h03Si2g aliapi& for mounting on a ve- 3, king held by locking pins 7 3 . Prior to landing, the 5 hicle; locking pins 73 are .ekctricaHy withdrawn from their @) a mbutdr cyzinder slidably dispused in ~ e i d locking position, releasing :he cylinder 27 h r extension housing for extending and retracting mation; under force of the springs 27. Wlim !he cylinders 1 7 (c) a piston telescopically received in said Cj*lindet have ex@ndc.cf a prbper predetermined &&imx, exten- with one end of said pistoh bejag within said Cy&- sion stop& by t,& rxtension s t ~ p 75 and 77.
der and tbe other end of said piston pro$efing freua The cyiiiders ark then free to slide back iab the housing one end o f mid cylinder; 1 5 .
(d) a yie!dable foot portion carded by said ather end The flight vehicb 11 descends substantially vertically of said piston; and initial contact with the landing surfme is made by (e) a crushabls ener~-zbsorbing material W S d 014t o r more of the foot members 37, the number de- 15 within ssid foot portion and within said cyliider; pending on how lwei the landing surface happens to be.
(f) said crushable material within said cylinder being Assuming a landkg surface slope of about 15 degree% contiguous with said one ead of said pislm wfiereby such as illustrated in FIGURE 1 , only one o r two foot retractive sliding of said piston within said cyfider members 3? vi.ilI initiaiiy contact the lahding surface.
will result in a crushing of some of said material; The kinetic energy of the particular strit QT struts snaking 20 (9) a switch associated with said m t poortion respon- contact is zbsorbzd by the foot 37 of each s V u t yie!dably sive to pressure contact of said foot portion w i t h a sliding u p on the piston 33 and crushing the crushable surface; material 45 thereby eliminating rebowid o f the foot from (h) m a n s responsive t3 said switch for locking said The plunger 51 slides upwardly the contacting surface.
cytinder against retractive slirfing w i t h said suppart with she foot thereby closing tiis pressure swiwitch 53. 25 housing.
The cylinder I7 of each conecting strut w i U then slide 2. The energy-absorbing device as defined in claim 1 freely within its housing 15 urltil its diametrically op- including means for sfidqbly extending said cylinder sub- posed strut cortacts the lar,&g sorfsLe similarly closing sequent 20 f ~ c k i n g thereof against ierrucljvr: sliding wi&h its switch 53. '&e eiectricat de%iccs 1 @ 7 , which release the locking pamk 95 of diametrically opposed struts, and 30 said support heusing.
3 . The energy-absmbing device as defined in claim 1 the pressure switches 53 of dianieiricalIy opposed struts wherein said locking mearts indudes a tootfied rack car- are series connect@ (see FIGURE 9) and the circuit ried by said cylinder and a pawl pivotally mounted d j a - closes only x5cn both struts of art opposcd pair have cent said rack for engagement therewith, contacted the landing surface. nerefore, the sliding up- 4. A flighs vehicle landing gear system compr&hg: ward of any strut making contact will not be stopped 35 (a) a plurality o f landing struts carried by the Qo1.tom by its locking pawl 95 untii iti diametricaliy opposd portion o f said vehicle; strut has also made contact. Both struts are then locked (b) said stmrs beins arranged in pais with the struts simul?aneously by the pawls 95.
of each pair being diametricafly opgosed; At the time the cylinders i 7 o f diametrically opposed (C) each of said struts comprising a mpport hoBing stmts, which have conzacted the landjns su~face, are re- 40 havhg a tubular cylinder slidably disposed therein strzimd sliding up further in their housings I5 the for extending and retracting motion h i o w said ve- flight vehicle stiU bas some vertical velocity. I o bring bile; the flight vehklc to rest in a controlled manner after (d) said cylinder of each of said s t ; t s having 5 piston locking of rht pawls 95 the pistons 33 slide upwardiy tekscopically received therein with one end o f said Within the cylinders 17 thereby crushing the energy-& 43 piston being within said cylinder and the ofker,e& o f sxbing malaria1 61. The maximum vertical force im- said pistbn projecting €mm the fawer m n d o f said p o s e d Qn the flight vehicle 11 is predetermined by the cylinder; selection of &e dzasity and cross-sectional area of the ( e ) said.piston projecting from each of said cylinders crushable material 61. The crushable material prefer- having a yiddabk foot portion carried by said other a relatively constant load versus stroke charac- 50 ably has end thereof adapied €or contacting a landmg sur- teristic such as obtained from metallic honeycomb.
fa*; S i n c e the crushing of t5e energy-absorbing materiai.
(f) a crushable energy-absarbing material disposed 61 can only occur simultaneously in diametricaliy op- wiX& each of said foot pertione and within each& posed struts, the wrtical loads 3pplied io the flight ve- said KVwws; hicle are always balanced and cannot cause any overturn- 55 (g) Said cmshable ntakrial within each o f said cyiin- ing moments. Therefore, the i&ht vehicle remains in a ders hk?g can&uo@s w i t h said om end of the piston substaatfally level or -+ertical nGtEde throughout h of said cylinder whereby r e t r a d m o f said pistm landing process.
within &e cylinder will result in a cmshhing a f some M e r the landing is coztpletrd, minor deviations d the Of said flight vehicle from a level attiwdt may be e2rrected by (h) a switch assodated with each o f said foot pmzms USB o f the jacks XI5 prosidtd for extending any of the raponshe to presswe contact o f s d foot p&ha stmts 1 3 , as desired.
w i t h a landing surface; %!'hide the sinrult&neous locking o f diarnetrially op- fi) said sustches associated with each pair of ~d posed struts in the number o f two bas been dg:scribe.d, it & a p ~ t i i c a l f ~ ~PP- struts .being electricalxy ~ 0 % is understood &at &e invention con:en;plaIes :hat the 1 1 5 nected in series with &e series conmctb f o r ea& .
simultaneous locking and cmrbing of &e e w r a absarwr pair of switches being excksive of s e r k m- may occur only after a number o f WULS grgatcr thain nzction o f oaer pairs of swircber; * o fiave contacted the Janding surface. For example, (j) means respopdve $0 said swirclhes fer shulaaae- wbfilX a *bdd fmdmg gear S Y s e D j w o h d 70 ous]y IQ$*&~ =id of ei&er of faid &f sty&, the s t n n s w c J d be lfickst: &ncXaneously only m t s e-~ins: retractive sliding w;&in said supgort L%r all ihree had rrtntacttzd the landing surface.
y&n5ingr ~viou~Yy, many m&iical.ions and variatias o f the 9 . ~er,py-absorf.i~g dedce wmpssiag: prwni invention are possibie in the Sight of the a b v e (a) a su~port hws.og adqaed h r mounting on a v c teachi'np. It is, therefore, to b z nnikrstood +at w i t h 16 hicle;