7 is laimed is, ,W,hat 4 @c 1. In air pick-up and delivery apparatus,,the r.ombinat@on of a @pqir of. - ground @stations @each ,by presentinge,'IeGpadapted,tQbeengaged@ 'conne.dting -means Qn an a-ircraft, :an object -to be 5 piaked@up ronnected @,to one @of said loops, an energ@r absorbing unit operatively connected to the other Qf said loops, @ an 7aircraft, means an sald aircrgft to @engage,each @of saad loops, @an -ob@ ject to @be delivered -connerted to tbemeans that 10,, is fintended for connection 4with the -loop connee,ted tG said.eiiergy @absorbing unit, iand -a:piek" up unit @in said tiircraft operatively connected to the:means whieh'is:interxded for connection-with tte loqp. connee-ted to:said oWeet:tG be -pidked up. 2. in.air -,pick@up @and delivery @apparatus, the combination --of @an - aircraft, a i>ick-up -unit -on said aircraft,,&:delivery,ahute ori said aircraft, an@object,to-lie@deliveredin-said deliveiy-'-ciiute,@a pair of contact arms carried by said aircraft,@a 2,0 hook detachably -carriecl -at -the . Xree extremity of each contact arm, a line connecting one of said hooks,witil @aiO,.unit, another line conneeting the Qtlier Qf :sa!4 . bool@s with . @said; object to @ be delive:red, a.pair of ground statioiis,arranged in side. 25 sicle relat-ion, each.Qf said ground stations includiag, @a adapted to 4e, engagi@d:l@y Qne of -said -hooks,,an object to be pick d up Qo;inected to, onp., of said loop-5, arxd -an, energy -ab@sorbing u t ,ni operatively @cgnnected to @tho,otlier,of s,14d $.G IOQIPS. -3. In air,pick-up aad deliver-7 api>aratus, the wnihination- of, an aircraft, a,@pick@up..unit on said airqraf t, - a,delivery, - cliute - on said aircraft,, an, obilpe,t to be deliver4@d,iii @@aid, chute.,.mean;s for@ yield, a5 ably maiiateining said,objeot in.saidchute, a pa@r of @ (*nt4e,.t, arnis hingcoly -,rnQtla@tccl, on :said airexalt @iii 4ide by side @l?o4tic>n, a piqk@u t p@liook de,a.cha y-r @, I bi aqunted to the.@fr@e euld,of one,of, said lioo!4 with@said 4 delivery hoqk@cletAclia,l@ly@ oarr@ed@at the-free extremity- of,tlie other a -@aid@arm@, a@Iiiie, connortizig-s@aid delivery lioqk with@4aid object t(> be de4vered, a@pair of ground stations iii,side @y, side position, eacii,Of @aid gxound @stat@ona ineltidiriu -a loqp, held in .:spread pqaition by the.reipeetivez station @apdl-adapted @to be engaged by one of said hooks, an object tQ be picked up connectedto,the loop adapted for engagement by seiid pfek-up 'hook, and an energy absorl@ing unit operatively conrtectecl to,@the loop lati@ndedfor-engagernQnt-witlisaid.deliver hook .4. ln:air deliver-,y apparatus,@ t@ie combinatiort GT a-a, aircro@ft inqlucung a delive,.ry cliute, means fo@r yiel-dtngly r@Qtaining ,,an odject to, be delivered in A,%Id chutp, i@@ cc>ntact,- arm, Qii:sa@d,aireraft, a hook d.eta,chably Qarried. at tlie,free l@nd Df *a4d axni, a, line -liaving @-one en.d coranected to-saidlxooic @aad th.e other exid Pdgpted@ f or@ coDx%E@et@p1i. to: an ('Qject i7 ,a saictphute,, aiground,,,@.t4tion@including-an,@erected loop, said loop'peixis adapt@edifor@en .,g4gment by said @b@ook, @and ail izi-iprgy- @ abs(>rbiag unit, opexe,tively c(>nnecteclito said- loc>p. 5 ' Air delivery @ appara@tus -coraprising an aircraft,, -a, "delivery ichute ixx @said;aircraft -,QPeliing' rearwardly tliereof, @an I object -ta @,be @ dehvered iin said chute, means for yieldably ret&iWng,,said Sect in said@cliute, -a @contact -arm @depeading -fror& said @@aircraft, a -hook detaebably mounted oli the free -end of @said arm. a Jine connecting said hook -to'se@id (ibiect, a ground station including a @loop inerected position whereby it @ia adapted @for engagement by 'said licoiitact arm and -hook, andan enetgy absorbingunit @connp-cted to @said loop. 6. Air delivery @apparatus comprising @an air@ craft, an,@oblect to bedelivered.on,said aircraft, a ground station including a:loop. in -erected position, - means on,saidaircraft @for effecting a @connection @@betw-een said:objeet.and said:loop, -an energy.absorbing,inlit, and @means for @connecting said , energy @ubsorbing @ unit to -said loop and. rencfenng said @uxiit e v at a,p int-spaced abo e f f e t i e @ 0 v e the @ground on which @said @ground @station @is mo unted!substaiitidllyat,@,the Iieightlof said loop. .7. -Air @delivery appare@tus comprising an 7aircraft, an,objectto.be delivered.orisaid@aircraft, a groundstation including a. loop in erected positiou and having a toP ply spaced above the ground on which.said:station,is mounted, means for effecting a connection @ between said loop @.and said, object, an eriergy. abwrbing unit, - a @ line c(>nnecting said energy absorbing@unit@to said.lgop, and means for supporting said @l ine at a height substantially the same as the height, of said top ply whereby -said energy absorbing;unit is @rerydered effective to counteraat the gravity, action of said object @as it isdelivered. Air delivery apparatus comprising a supporting structure including:a platform 'in upraised position, an energy absorbing unit on said @plat@ form,. a ground station:including an erected loop, a line @.cdnneeting said loop 'to :said unit,:an -aircraft, a: delivery chiite: in @said aircraft, an object to'be d@Nvered in said chute,- nieans:.-for yieldably retaining said objert@in-,said chute, a contact,arm depending from said aircraft! and adapted to @enfree eiad of said arm@,.whereby:it is adapted to effect a connection with said loop, and @a line connecting said hook to said owert. 9. Iri air Pick-up and delivery-lapparatus, a@pair 45 of:ground,stations in side by side position, one Of said. ground stations intlilding a pick-up loop having a - predeterniined diametrical dimension, an object to be picked up-cgnnected -to said: loop,@ the other-grouifd-station including a delivery loovhav50 ing a,substantially greater@ diametrical dimension, an energy Absorbing, uriit operatively connected,, io, said d6livery'loop,@ an aircraft, a@i@ick@up@ unit on said eircraft,,a pick-up arm depending%from said aircraft, a pick.;,up -hook detach&bly,-xnounted -on .55 the free'end 6f @said, arm, said'hook having a tbill that is -spaced%from said arm just,@sufficiently t(y provi)de@elearance,for ftCCU ratt-ly-Teceiving., said pick-up @ loop, a 1 line, connectin@g said hook@ to said pick-up unit, a delivery arm depending from said 60 aircraft, a delivery hook detadhably mounted on the free end of said arm, said delivery hodk including a, bill spaced from said 7arm sdfflciently- to provide clearance for@receiving-said@ dolivery loop, an object to @: be delivered. on said aircraft, @ and @a 6-5 line connecting said -object,to'.be delivered with sa-id delivery, hook. - R O B E R T B . - C O T T O N , Arms, 4 line7operatively@cQrknocting@,said piek-i;p@ 40, gage.said loop,,.a@hook'detachably mounted at the

x-alented Dec. 30, 1947 2@433@437 UNITED STATES PATENT OFFICE 2,433,437 SEM[ULTANEOUS AIR PICKUP AND DELILVERY SYSTEM Robert B. Cotton, Lansdowne, Pa., assignor to All American Aviation, Inc., Wilmington, Del., a corporation of Delaware Application March 28, 1946, Serial No. 657,871 9 Claims. (Cl. 258-1.8) This invention relates to air pick-up and is concerned primarily with the provision of simultaneous pick-up and delivery operations. At the present time the art of air pick-up is well established and recognizbd as a thing accomplished. There is at least one air hne which has been making regularly scheduled runs over established routes since 1939 and these operations are essentially air pick-up, i. e., rnail is picked up from the ground without stopping and other maii is delivered by being dropped from the aircraft. In accordance with what is now recognized as conventional practice, a container encasing the mail to be dropped at any particular location is trailed at the end of a line an appreciable distance back from the fuselage as the aircraft comes in to make a pick-up. At what the flight mechanic determines to be the proper time, this c6ntainer is released and drops to the ground just before the pick-up is made. There are certain undesirable features which attend this practice and which are intended to be obviated by the claimed invention. In the first place it is impossible if not highly impractical to achieve even a fair degree of accuracy irl the delivery. The coiitainer might everitually wind up at some spot over a wide area. This, of course, requires the use of a fairly lar@e plot where the ground station is erected to accommodate this inaccurate delivery. In the second place, the container when it is released from the aircraft has a velocity substantially equal to that of the aircraft. Thus, when it strikes the ground it is subjected to severe shocks and jars which tend to damage the container and seriously shorten its service life. With these conditions in mind this invention has in view as its foremost objective the provision of new and improved apparatus for delivering a cbntainer from a moving aircraft to a desi @red location on the ground with a high degree of accuracy. Moreover, this delivery apparatus includes means for neutralizing the forward speed of the aircraft which is imparted to the container before the latter strikes the ground. In carrying out this idea, in a, practical embodiment the invention proposes the use of a ground station offering a loop for engagement with contact rneans on the aircraft and which contact means is connected to the container beingdelivered. This loop is operatively connected to an ener . gy absorbing unit which is substantially the equivalent of a pick-up unit which is included in the aircraft for the pick-up operation. 2 vision of apparatus designed particularly to effect simultaneously air pick-up and delivery operations. In achieving this object the aircraft performing the operation is provided with the usual pick-up unit and a pair of contact arms. Detachably carried at the end of one of these arms is a hook which is connected to a line wound on the winch of the pick-up unit. Detachably carried at the extremity of the other arm, is a 10- hook that is connected by a line with the container to be delivered. A pair of ground stations are arranged in side by side relation so that the loops held in erected position thereby are adapted for substantially simultaneous engagement bY 15 the pick-up arms. One of these loops is connected by a leader to the container which is to be picked up while the other loop is connected to a line that is taken up on the winch of the ground based delivery unit. 20 When the plane comes in the arms engage the loops together. Both hooks are pulled from, the arrns. This causes the container to be delivered to be pulled from the aircraft and this operation takes place under the control of the ground based 25 delivery unit. At the same time the other hook is pulled from its contact arm and connects the contginer to be picked up with the pick-up unit on the aircraft. A somewhat more detailed objective of the in30 vention is the provision of an aircraft including a chute which is adapted to receive a container being delivered and which chute includes means for yieldably retaining a container therein. While it is believed that the span of the loops 35 Of the ground stgtion are sufficiently wide and the contact arms ori the aircraft may be spaced sufficiently far apart to render extremely remote the possibility of the pick-up arm engaging the delivery loop, yet in the interest of abundant 40 precaution the invention ha's as a further object the provision of apparatus of the character above described which is designed to positively preclude the possibility of effecting a connection between the hook of the pick-up apparatus and the loop 45 of the delivery system. In attaining this end the loop of the delivery system has a diameter appreciably greater than the lbop of the pick-up system. The contact arm and pick-up hook are so arranged as to provide just sufficient clearance 50 for the small pick-i@p loop to enter between the bill of the pick-up hook and the arm and effect the connection. A line of greater diameter such as the delivery loop will not enter this clearance land if through inadvertance it should engage the further object of the invention is the pro- 55 -contact arm and slide down to meet the bill of

3 tiae pick-up hook, it will merely knock the hook off the arm but will not effect the connection. A pick-up opetation is ordinarily made from a fairly low altitude. If the container is delivered from an aircraft making the pick-up it ordinarily rj will not fall any distance sufficiently great to cause ap e ,p;pciablp dam4gp. 14c?@t of th damage and wear 4pa tear on the container is c,aused by the forward velocity. This forward velocity is neutralized by the delivery unit. However, th ig invention has in view as a further object the provision of apparatus of the type indicated which includes means for neutralizing or counteracting the gravity action to which the edntainer is su@= , 2,433,437 4 Parts of the fuselage broken away to bring out the location and construction of the chute for the container to be delivered. Mgure 9 is a side view partly in section and partly in elevation of the fuselage with parts of the latter broken away to bring out another arranger4ient for apeomm dati-4g the container to be7'd' livered. Figure 10 is an enlarged detailed view of the 4qlivery chute per se. This view is taken as a section through the chute with the container shown inelevation. Figure 11 is an enlarged detailed view in side elevatign of the oilter end of the pick-up arm and Jected in being delivered. :In carrying ou@t @@is 1.5' @ii6ok, pqrr-ied t e e y, and idea in a practical ernbodiniei@t, ffi@'lln,e v@hich l@ qprq 19 is a, @imilar view of the outer end of taken up on the delivery unit is rendered effective the liv ry 4rm., Oe p at a point spaced above the i-iou-nd. 'this' S'P'ac-- R6ferrin-g n6-w to the drawings wherein like ing is comparable to the height of t4,p tp ,p ply refer@p9@ characters denote corresponding parts of the ground station loop and may be esta@ll'slie-d 20 and first, more Particularly to Mgures 1 and 2, an either by causing the Iiiie to pass over a pWIe aircraft silch as adapted for air pick@ud oper@.aalt iiiat'@eiihi 6i m e@ @@it itself at such tiops ref@e@iea t6 iii'its ent.irety by the fefere ce, ounting,th d 4ei6 -on -- r- cha ght. In eit er event with proper c t ol racter A. This Airer4ft plgy @e of any of the Of h braking in@irur@entali@t;ies of the deliveu @po We4 wn modelq pr P.Oils ruction@ wl@lcll qre unit the dowriward fall of the container p@ay 2,5 suitable to air pick-up ii@qge. The aircraft A ini!, cli6eked' 'a't' 't'h'e -sa"rile"time t at its forward ve-7 el-udes. 'a iu ' ja . @ p @ ,g p 1 0 W hi c h h ot ls e s a pi c k 7 u p, u n locity is decelerated, indicateo iij Ootted lines at, I f in Figure 8. Plc ti@6se @@d other more detailed objects and ad- up units such as that reprpsonted E@t I I are now y,:ipta.aes of the inventi6n wfli in par ecome a - w6il-k'now'n."'AS good illu@tr4t!ogs pf such i)ick@ @.P p4rent and in pqrt be her6inafter stated as t f e -4e 30 up units re erence is mad to the patents 0 des tian of t4e invention proceeds. ]@lummer, Nos. 2,373,413 and 2,373,414, both dated Prip The' invention ther A@ o efore comprises apparatus ril I, 45. The f 8 I e JO al o, includes a @u p,ag for simultaneiD@sly.'@fk66@i@g E@ir. p@ck-@@ and de- delivery chute such as that sho@wn at 12 in F19U.@p, livery opera't'i@@ T@iis api-,arat s is character- 9 or 13 in Figure 8. It will @.q noted that eaph o@ ized @is inel qing, a p.@kir qf grouiid stations offer@ 3-i thE@ cielivery chutes t2 and 1'3, ppens rearwardly, ixig loops in @rect6d side bk side position, and a of the fus@elag@. Refer-ring now. More partfcularly to Figures I and 2, a p,air of contact arms are showii 'ai @.1 4 and (5 Tespectively. Tliepe arms may be con iiected at tAe top by a commpa yoke or framewqr4 I EL which is prefer4bly hingedi@. mounted ort thq unclerside qf @ho fuselage 10. The. partiqular y elG,and,armsf4gndiS manner in which the ok e q?,@ried th reby are hingedly mounted is not an important part of this inverition. All that is re_, quired is that, tlie ar, -Ms l@@ s:useppti ble Gf bei.ng *ithdrawp (r @pti@,acte4 from the di@penciing ppe,@.@, qtiyp, po@itioll. Obv-1oiisly, this, i js necessarv during landing- and takirig off and in order to min@i@ the invexitioq re@erence ig@qy. b@ i6. i!26 foilowr @iP, m'ize' @es e Rm@ a@@ lowered in thi;@ win r !stance ii@g c r@ w k ,Iescrip, ;pn and @@qqoAil?4nying d a ipg4 ope@ative position only w-hen a Pic @up. aAd deli@er w,liorein: y operation is to. be mad Figure I is, a rear. view shpwin,@, an aircraft The particular can tructioxi. qf t4e c ntact arms s about to@ malc'6. sim@ita@6ous and d a are. also. no . t a. part of this in-vention. p@94@qp e-livpr-y 4 L,ra 6n 'ti'n z"kopp-r'da' e, th 1?recepts of 5@a C with e ontact arni@ uch as this are iiow- well-k GWA op AP" A this v6lt tn ion. andava,ila@lleto.th(@,p@b.l ic. @@charmsare.show-a Figure. 2 is. a perspective -View. looking more, in the Plummer p*ents above referred to and include a track d6-i oks may be slid 40M o@e, @id@ siiowi@@ t@4. sam@ 6pe'ratl'o'n. wn'which J@6 li@gure 3 'L,3 a view; ih @ide elevation, somewhat prior to the 'P'& 461ive@y, 6p@e @ . @ , -@4P, ra@igris. di@gi;axhM@atic, 's@6,@in elation o t - e ai@@ 6 g, h The arm 1'4. is i d-en-t@,fied a the piel@-tip aM C;r@it @o, tli6- giotind@' si@tidii ju,st b.6fore@ Gontact. nd at iis @lo 'er' 'or@ free. extrem, ity carries a hookis a view. similar to Figure 3 sho-w-r represented somewhat, cliagrammaticail ing the, relation of the, various components imme- The bo6k 1-7, 'is'@etachably ii6ld- !a positiG.M on t4e,, dia'tely afte@ 66@t.@Q,t arm (4, in the m nuer illustrated a d described n. .Fidtire 5 is another Side view siniilax@ to Figures 60. in the abol.7e iden@ifted Plummer, patents. A line 3, @nd 4 developirig a further atag of simulta7, 18, has. its outer or f@ee. pi@d qq4p teo @o th hook neous p'xck@up and delivery,. 17 aiid, this- line plasses through. pg pp@ning @,atp@ '@aoth6@@ side, view si-milax t @he. i@terior. of the fuselage l@G @7@heia it i t n, Vp, Figure 6 is still o@ s Fiiti@e@ 3, 5 r s'tage, of the l@-M , qi@ tlie, , t if. siiniiltanebii@ 6@erations. A, hook 19 is- similarly- -mou.ated o the Gu@ter, or 20- h a s o n p , e a q tion briiigii@g o@i @ 'm6difi@ition- "m - w'nic'h t4@'i connerte'd'-'to'thi's' -h@oo'k' Wh' @ it.% other- end is, co'"@@ g@ound bas,ed d@i@vp@@ iiiiit, i4,@ raised fi,-oni the nectpd. to 4.1 qoriiaiii@@@ ic, be,deli - re@ @d as' indi;@ate4i vie grou d at 21. .P!;;e, 8. is g. t @lan -V,.keW, pt @4p. 4ir r ft, w 7 @ Referr-ing no-w PR- , 1,@, - @tll, P;k v, . 19 ;4 ." .11 ilz ; 4 , , @, @ 1- I "Aq @ 4iqp4;@L OPS. to engag6 @aid io pi -ek@ pa@ir of c n ae 4Vm@ 94 th r i' i@ airc a t aking @4p l@ick-pp and delivery and which arms are qdd ted @P, -UP lin@t i - ks @ncludp4 in the a4craft and a l@4,e included thaerein is cOn- 40. nect6d to a ho.6k on tEe pick-up ar The con-7 E4nqr @9 pe,d,h loably retained in 9, t e v,'eied@ is '@ie@ chiite in the aircraf@ .1 d is co6iied@d'to a ho k 'p @ de I tachab, 7 Mountpd on t, (e del@very arra. Thp 'to k con be p@c edr@qp @,, connected to the 45 I)ick@ qp wli@@6 @L g q @a@ed energy o@bsorb@o Ing de;@yp-ry i4p# @s'f qpxl6cted to the d h @Ty loop. For e@ fi@l@ c ,@nd uiore compl ete understandi,ng of 7Q; Figure 7, is a perspect@ve. view of a ground, sta-, free end of the alrm. i@, Wnd

2,433,437, the container to be delivered is therein depicted and identified in.its entirety by the referende character C. This container has a, rounded nose. 22 which carries the connection 21 in the form of an eye. Regardless of the particular location 5 of the chute as depicted in either Figure 8 or 9 the container C is yieldably held in position within the chute by the detents 23. There is preferably a detent 23 on each side of the chute in opposed relation. Each detent comprises a.casing 24 that 10 is attached to the wall of the chute and -which encloses a rod 25 that is slidably mounted in the casing. The inner end of the rod 25 carries a shoe 26 which is shaped to conform to the curvature of the nose 22. A spring 27 yieldably urges 15 the shoe 26 against the nose. It is evident that when a sufficient pull is exerted on the line 20, the nose 22 may be drawn past the shoes 26 retracting the latter against the influence of the springs 27 thereby withdrawing the container C 20 from the chute. Referring riow again more particularly to Figures I and 2, a pick-up ground station is designated generally Gi wliile the delivery ground. station is designated 02. The ground station Gi 25 comprises poles 28 and 29 which hold in an erected position a pick-up loop 30. The ground station G2 comprises poles 29 and 31 which hold in an erected position a delivery loop 32. Each general type are now well-known. One stich ground station is illustrated and described izi the patent to Plummer, No. 2,367,607, January 16, 1945, and substantially the same type of groiind 35 station is depicted in the patent to Ballard, No@ 2,369,518, February 13, 1945. The novel feature of the ground stations Gi and G2 is that the pole 29 is common to the two. It will be noted that the top Ply of the loops '@o'C 4o and 32 is held in position by releasable clips indicated at 33. A container to be picked up is shown at 34 and, this container is connected to the loop 30 by the connection shown at 35. A grolind based delivery I -.') unit is shown at 36. The unit 36 includes a line 37 which is connected to the loop 32. The unit@ 36 is preferably a duplicate of the unit I I which is mounted in the aircraft A. For the Purposes of ihis specification the details of construction 60 of the unit I I needs here not. be described. Either of the units shown in the first two Plummer pate'nts herein identified may be employed as the ground based unit 36. It sufflees to point.out that such a unit includes a winch on which line r,5 37 is taken up, braking instrumentalities associated with the, winch, and time delay r4echanism for controlling application of the brakes, Operation 00 In describing the operation Gf the apparatus hereinbefore discussed, it will be assumed that the contact arms 14 and 15 are lowered into ef - fective positions with the hooks 17 and 19 de- 65 tachably held in position on the extremities, of the arms. The coiitainer C to be delivered is .Positioned in the delivery chute and yieldably held therein by the detents 23. The ground stations Gi and G2 are erected and the container 34 70 to be picked up is connected to the loop 30. As the pilot brings the aircraft in to make the simultaneous pick-up and delivery, the arms 14 and 15 engage the toP Plies of the loops 30 and 32 respectively. These top phes slide down the 75 arms and engage the hooks 17 and 19 respedtively. The relative positions just before engagement is brought out in Figure 3. As the loop 30 pulls the hook 17 free of the arm 14, the line IS together with the loop 30 are straightened out and the unit I I is brought into operation to gradually accelerate the container 34 to the speed of the aircraft. At the same time the loop 32 pulls the hook 19 free of the arm I 5 and straightens out the line 20. As this line becomes taut it pulls the container C from the delivery chute and the; ground based unit 36 is brought into operation to gradually decelerate the container C from the. speed of the aircraft and bring it to a stop. As the flight is continued the flight mechanic may operate the unit I I in a well-known manner to reel in line 18 and 'bring the container 34 up iiito a position in which it may be drawn into the aircraft. First modifteation It is believed that under ordinar-y conditions the simultaneous pick-up and delivery above described may be carried out without a likelihood of the pick-up arm 14 engaging the delivery loop 32. However, recognizing that it is just possible for such a condition to arise, the invention proposes to guard against having the delivery loop ures 11 and 12, it will be ngted that the pick-up hook f7 includes a bill 38 which is spaced from the arm 14 to provide a clearance 39. This elbarance 39 i-s just great enough t( accomm(date the diameter of the pick-up loop 30 such as shown at 40. The pick-up loop 32 has a greater diameter as shown at 41 in Figure 12. The bill 42 of the delivery hook 19 provides a clearance 43 which accommodates this larger diameter loop., However, if the large diameter lodp 41 should@ engage the arm 14 as by accident it would slide down the underf ace of the arm until it met the bill 38. As the clearance 39 is not sufficiently great to accommodate the larger logp 41 the latter will merely knock the hook off the arm but will not enter the hook and e-ffect the connection. Second modiftcation Ref erring now more par I ticularly to Figure 7, it will be noted that a platform 44 is supported in ar-i upraised po@ition by supporting structure 45 at a location conveniently to one side of the groupd station G2. The ground based tinit 3G is supported on this platform 44. It is evident that as the delivery line 20 and loop 32 become taut the container C to be delivered is stopped from a Point upraised from the ground surface. Thm, the braking instrumentalities which are included in the unit 36 are rendered effective to neutrali2;6 or counteract gravity action which causes the container to fall. Thus, not only is the forward or lateral velocity.of the container gradually diminished, but the larger part of its fall under gravity action is arrested before the container strikes the ground. While preferred specific embodiments of the invention are hereinbefore set forth, it is to be clearly understood that the invention is not to be limited to the exact constructions illustrated and described because various modifications of these details may be provided in putting the invention into practice within the purview of the appended claims. of the ground stations Gi and G2 taken i,)dividu- 301 connected to the pick-up line with resulting damally present no invention. Ground stations of this age. Referring now more particularly to Fig-