US2348342A - Airplane pickup mechanism - Google Patents

Description

' May 9, 1944.- E. a. HILL I 2,348,342

AIRPLANE PICKUP MECHANISM Filed June 22, 1942 2 Sheets- Sheet 1 3mm fawn/m 6 H14 L May 9, 1944. E. s. HILL AIRPLANE PICKUP MECHANISM Filed June 22, 1942 2 Sheets-Sheet 2 Patented May 9, 1944 UNITEDSTATES PATENT OFFICE AIRPLANE PICKUP MECHANISM Edward G. Hill," Richmond, Va., assignor to G.

Tucker Smith and E. Gavan mend, Va... as trustees Application June22, 1942, Serial No. 448,007

12 Claims. (01. 2581.6)

This invention relates to airplane pick-up mechanisms, and more particularly to such a mechanism of the type wherein a catapult projectsthe article upon the picking up by an airplane-carried hook of. a flexible loop connected to the articleon the catapult.

In a mechanism of the type referred to, it has been proposed to arrange the article to be picked up on a catapult latched against movement, and to connect a flexible element, such as a shock cord, to the article, with a loop therein suspended across the tops of a pair of spaced masts. Such a mechanism has been provided with means operable upon the engagement of the portion of the loop between the masts by an airplane-carried hook to release the catapult and thus project the article, the latter being accelerated by the catapult so that it attains a speed approximating that of the airplane at the time the slack is taken up in the loop.

A loop of the character referred to is generally triangular, one point in the triangle being at the point of connection of the loop to the article and the other two points being at the tops of the respective masts. When the airplane-carried hook engages the loop and pulls it loose from the masts, an appreciable period of time elapses before the triangular loop is straightened out, and it is during the period that acceleration of the catapult takes place up to approximately the airplane speed.

It is essential in a device of this character that the interval of time referred to be relatively uniform in successive operations of the mechanism in order that the catapult may properly accel-- erate the load.

An important object of the present invention is to provide a novel apparatus of the character referred to having an extremely simple form of.

mechanically operated catapult latch release mechanism which is operative instantly upon the transmissionof the initial pull of the airplane-carried hook on the suspended loop for releasing the catapult latch, thereby allowing a proper and relatively uniformly predetermined time interval during which the article will be Hill, both of Richare eliminated and wherein the relatively heavy and cumbersome features of prior mechanical release mechanisms are eliminated.

Otherobjects and advantages of the invention will become apparent during the course of the following description.

In the drawings I have shown one embodiment of the invention. In this showing:

Figure 1 is a side elevation of the mechanism showing an airplane in flight thereover and about to engage the loop connected to the article,

Figure 2 is an enlarged fragmentary central vertical sectional view through the rear end of the catapult device and associated elements,

Figure 3 is an enlarged end elevation of the apparatus, 7

Figure 4 is a detail perspective view showing the catapult carriage and associated elements, the loop and supporting mast therefor, and the flexible latch release device,

Figure 5 is a section On line 5-5 of Figure 2,

Figure 6 is a detail perspective view of the casingfor the release rod gripping mechanism, and,

Figure 7 is a detail fragmentary perspective view of a portion of the pick-up loop.

Referring to Figure 1, the numeral 0 designates anairplane below which is suspended a relatively rigid arm II which is adapted to be swung against the fuselage of the plane, or downwardly to the operative position shown in Figure 1 wherein the arm slopes downwardly and rearwardly. The arm I l is provided at its lower end with a hook l2'for the purpose of picking up a load or article in a manner to be described. The hook I2 is carried by a cable running through the arm ll into the plane and connected to a windlass whereby the load may be pulled upwardly into the plane, the fuselage of the latter being provided with a suitable door through which the load may be lifted into the plane. A cable I3 is connected to the arm II and has its upper end connected to suitable mechanism for pulling the arm upwardly against the plane to its inoperative position. The parts so far described form no part per se of the present invention and need not be specifically illustrated.

The catapult mechanism is indicated as a whole by the numeral l4. Such mechanism comprises elongated spaced frame members I5 each of which has an inwardly extending flange l6, and the flanges of the opposite frame members cooperate to form a trackway for the catapult carriage to be described. The catapult mechanism further comprises lower frame members ll connected at their ends by transverse angle iron frame members IS. The sides of the mechanism are covered by plates I9 extending from end to end of the mechanism as will be apparent. One end of the apparatus is covered by an end plate which is secured to the cross member l8 and to a similar cross member 2| extending across and welded or otherwise secured to the adjacent ends of the frame membersl5.

The endof. the mechanism referredto is provided with a caster wheel 2| having a draft connection 22 and pivoted as at 23 to a bracket 24:, and this bracket is secured to the end plate 20 and preferably also to the cross members l8 and 2|. The other end of the mechanism.issuppert ed by wheels 25 (Figures 1 and-39.

A carriage indicated as a whole by the numeral 26 is provided therebeneathwith a. suitable structure 21 carrying pairs of wheels 28 and 29 at its forward and rear ends and at oppositesides thereof whereby the carriage is guided by the traokways i6; The carriage is adapted t'o support any suitable form of article; such as a container 30, and is. providedwith an end wall 31 Whichbears against the article toimpart movement thereto when the catapult mechanism is re-- leased in a manner to be'describedi The end wall 31 is provided with a latch 32 engageable by a hooked'fingeror det'ent 33 pi-v otally connected as at 34" to the=upper-end of" a bracket'arm 35".. A' rod 3-6 hasits upper end connected to' the finger 3-3- and its lower end con nected to one" arm 3? of a bell cranklever 38, this" lever being; pivoted as at 39 to a bracket 40' and having'asecondarm'4 l'.

A control rod orbar 42'is' connected at one: end to the lever arm 4|. This bar may be-relatively small at; its-endconnectedto the lever arm 4| and has its rear end 43 tapered to-i ncrease in width as shown in Figure 4. finger 44 (Figure 2) is connected to one end of a spring 453 theother end of this spring being connected asat'fifi to atransverse element 4-? which may be welded or otherwise secured to the upper" edges of theangle iron members l-T. When the spring 45 is tensioned it obviously: tends to pull the bar" 42 and turn the bell crank leverw'ii; in aclockwise direction; thus moving the rod 36 upwardIytb=- release the finger 33. a

Referring to Figures 2, 5and 6', a cylindrical casing 48 is secured as at- 49 toa cross member 50- and a clutch element 51 fitswithin the housing 48- and is urged downwardly by aspring: A rod 52 limitsdownward movement of 'the clutch element 51-. The lower face 53 of the clutch member 5 lslopes downwardly toward the fi e-e: end of the bar 42 and contacts with a roller 54 as shown in Figure 2. This-rollerin: turn, nor mally engages against the top surfac'eofi the wide end of the bar and ho1dsthis=bar down against a coactin clutch member 55, having its" upper surface perpendicular to the axis of'thahousing: 48-; The clutch member 55-; inturn, iszheld down against a roller 56 carried by the; upperend; at a lever 51. This leveri'si pivoted. as at.58 to bear lugs 59 carried by the lowerien'd of abraoket arn-r fill preferably formed integraltwith the. housing: 48-. The bracket arm 6!) is. provided with; a. stop member 6| engageablei with the lever 51-, above: the pivot thereof; to limit swinging; movement. of the lever in a. counter-clockwise direction? as viewed in Figure 2'bey0ndl' the. position-shown: irr such figure. Therefore, the:- spring: 52. will. effect a: gripping action? between the clutch members 5|: and: 55 and any tendency: of. the. bar 42' tomove to: the leit. as ewed in; Figure: zwill tend:

to cause the roller 54 to move down the inclined face 53 and thus more tightly clamp the roller in position against the bar 42. The housing 48 is provided with a slot 62 through which the fiat portion of the bar 42 extends when the parts are in the positions shown in Figure 2.

The sides of the catapult mechanism are provided; with outstanding arms. 65- hinged as at 66 to be swung to-positions parallel to'the catapult mechanism and adapted to be hooked in extended operative positions by hook elements 61. Rods 68 are slidable in the ends of the arms 65 and are adapted to be held in adjusted positions by set screws 69..

The. bars 6'8. are provided at their outer ends with sleeves 'Mreceiving vertically extending masts H having their lower ends received in sockets 12 carried by heavy mushroom bases 13. The masts may be fixed against sliding movement vertically by set screws. I4 threaded through the sockets HT; The upper ends of the mastsare provided with fingers 15' sharply inclinedfrom the vertical in the direction offlight Qfthe air-- plane for a purpose which Will'beoome apparent.

A flexible pick-up member 16' is adapted to be engaged by the airplane-carried hook I 2 to pickup the article. The flexible member Hi' isin the form of i aloop connected to the articlefll; as. at'

1-1; and adapted when in operative position, as" shown in; Figures 3 and 4, to form a generally triangularshape; the three sidesof which are formed by" a. transverse: member 18 extending acrossthemasts. and downwardly and rearwardly: converging sides 19 which are connected to thearticle so at. the; point 11;. as stated; Thepor tions; of the flexible; loop which are carried by:

11136163111)? ofia number of highly flexible rubber strings.- or bands enclosed. an. expansiblewoven.

covering; I-t'willbe apparenthowever, that while the. use-oi such a flexible loop; is desirable; it: is. not: at: all essential, particularly for the picking up; Of; lighter "loads.

Centrally of the; transverse portion 18C of the? loop a non-elastic relatively light cord ill; is. con

nectjedt as: at 82' and this maybe. dOIIBTIIIBIBIYbX tying the end of the cord 8| about the centerof' the; portion 18 of the loop. The; cord 8| extends downwardly and rearwardly for connection as-at 8% to: the lower end of the lever 81' toexerta pull" 011713118 lower end ofsuch lever to swing: it and thus release the bar 42, as will be further described.

The. particularform of power employedifor pro-- jecting the. catapult carriage is of no importance. As. generally illustratin one suitable. means for propelling the catapult, I have shown ashock.

turned by a hand crank or otherwise. to windthe shock; cord 84 onthe drum to properly tension it.

It. will be obvious that the rod 42 must be moved rearwardly to set it ready for operation and in order to provide access. to the rod; one-of. theside plates l9 may be provided withadoor w (Figure,- l).

With the catapult carriage in position, the operator will reach through the door 90 and pull the rod 42 toward the right as viewed in Figure 2 to tension the spring 45, and such operation obviously swings the bell crank lever 38 to pull downwardly on the rod 36 and move the finger 33- to locking position. The finger 33 will thus hold the catapult carriageagainst movement to the left as viewed in Figure 2, whereupon the source of power for the catapult may be prepared for operation to provide a force ready to act instan taneously to project the carriage upon the releasing of the latch 33. This is done, in the case of the shock cord 84, by winding the cord on the drum 81 to place the shock cord under sufiicient tension. One end of the string 81 will have been previously tied as at B3 to the lower end of the arm 51, and the other end of this cord willbe tied to the transverse portion 18 of the pick-up loop, at a point which will be midway between the masts II when the apparatus is completely set up. The rubber thimbles 80 are now pressed between the fingers 15 of the masts, whereupon the masts are set up in the sleeves l and sockets 12 (Fi ure 1).

The apparatus is now ready for operation and when the pick-up plane approaches it will fly at such level as to cause the bar H (Figure 1) to strike against the loop portion 18 at a. point slightly above the hook i2 and as near as possible midway of the length of the loop portion 18. The thimbles 5t being sufiiciently tightly gripped between the fingers 15 as to be not too readily pulled loose and the loop being formedof shock cord which is elastic, the initial striking of the bar H against the loop portion 18 will cause the latter to move relatively downwardly and rearwardly into engagement with the hook l2. The hook will exert a sudden pull on the loop portion E8 adjacent the point 82 and this jerk will be transmitted through the cord 8! to swing the lever 5i in a clockwise direotionas viewed in Figure 2. When the lever 51 has swung to its limit of movement, the cord 8| will relatively easily break, whereupon the hook l2 will continue to move the loop portion E8 to pull the thimbles 80 from the fingers 15, these fingers and the loop portion 79 moving inwardly toward each other while the loop portion 18 bends at the point 82 until the elements of the loop 69 assume a comparatively straight shape.

The lever 5! normally occupies a position at a slight angle to the vertical with its movement limited by the stop 6| and the downward pressure of the spring 52 serves to hold the lever 51 in the position referred to. The very slight vertical movement of the roller 56 necessary for the.

axis of the roller to pass across the vertical plane of the pivot point 58 is very slight and ample leverage is provided for the slight compression of the spring 52 necessary for suchoperation. After the roller. 56 thus passes the vertical center, the

lever 59 will freely turn under the force of the spring 52. The downward pressure of this spring thus will be released and the spring 45 (Figure 2) will quickly pull the bar 42 to the left (Figure 2) to release the latch finger 33' in the manner stated. Thus the catapult carriage will be released and the carriage will be projectedgenerally in the direction of flight of the airplane;

It will be obvious that a small but appreciable time interval is required for accelerating the catapult carriage and the article 3!] to a speed approximating that of the plane. The present apparatus provides a very simple and uniformly opcrating means for allowing for such time interval. This time interval may be readily calculated in accordance with the plane speed, the inertia of the article 30 and catapult carriage, and the force applied to the carriage to tend to move it. Having ascertained such time interval with relation to movement of the plane, the cord 8| and loop 69 may be so'related to each other that the same interval of time is provided between the initial jerking of the cord BI and the point at which the loop 69 becomes relatively straight, taking into account the acceleration in the speed of the catapult carriage during such interval. By proper calculation, the article may be caused to be moving at a speed approximately equal to the ground speed of the plane at the point where all of the slack is taken up in the loop 16, and at such point the airplane will start to carry the load and will be, affected solely by the force of gravity tending to move the article downwardly after it is released from the catapult. Downward forces on the airplane are reduced to a minimum by sloping the trackways l6 upwardly, at a slight angle toward the discharge end of the catapult, and by employing shock cord in making the loop 75, thereby cushioning any slight downward forces on the airplane due to any downward force of inertia incident to a slight drop in the level of the article after it has been freed from the catapult.

From the foregoing it will be apparent that the present apparatus provides an extremely sinn ple catapult latch release mechanism which may be so accurately designed with relation to the pick-up loop as to provide almost exactly the time interval necessary for accelerating the load to be picked up before the slack in the pick-up loop is taken up. The release device comprising the clutch elements 5!, 55, etc., requires so little force for its operation as to permit the use of a relatively lightcord 8| which is easily broken after the latch mechanism has been released.

It is to be understood that the form of the invention herewith shown and described is to be taken as a preferred example of the same and that various changes in the shape, size and arrangemeni'. of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claims.

1. In an airplane pick-up mechanism, a catapult having an article receiving carriage, a pickup loop secured to an article on the carriage and arranged in open formation with a portion there'- of supported in position to be engaged by an airplane-carried hook, an element operatively connected to said catapult and movable to render the catapult operative for projecting the carriage, and a flexible element directly connected between said first named element and said portion of the loop and normally maintained relatively straight whereby initial engagement of the airplane carried hook will move said Qfirst named element to render the catapult operative.

2. In an airplane pick-up mechanism, a catapult having an article receiving carriage, a flexible element connected to an article on the carriage and having a loop, means for supporting said loop in open formation with a portion thereof arranged transversely of the direction of fiight of an airplane having a hook engageable with such portion of the loop, an element operatively connected to said catapult and movable to render the catapult operative to project the carriage,

and a direct relatively straight-line flexible con neet on. tweensaid element: and said portion of the loopv for transmitting movement: to said element; immediately upon engagement of the airplane-carried hook with said, portion of the loop. .3. In an airplane pick-up mechanism, a catapult having an article receiving carriage, a flexible element connected to an article on the carriage and having. a loop, a pair of spaced supporting members having means at their upper ends for releasably engaging said loop to, support a portion thereof at an. elevated position transversely of the direction of flight of an airplane having a hookengageable with such portion of the loop, an element operatively connected to said catapult and movable to render said catapult operative to project thecarriage, and a direct relatively straight-line flexible connection between saidelement and said portion of the loop to trans- J mit a pull to said element to move it immediately upon engagement of said portion of the loop by the airplane-carried hook.

4. In an airplane pick-up mechanism, a catapult having an article receiving carriage, a flexible element connected to an article, on the carriage and having a loop, a pair of spaced vertical masts each having its upper end provided with a slot releasably engageable with said 100p to hold the latter in open formation with a portion thereof extending transversely of the direction of travel of an airplane having a hook engageable with such portion of; the. loop, an element operatively connected to said catapult and movable to render the catapult operative to project said carriage, and a direct relatively-straight-line flexible connection between said element and said portion of the loop approximately midway between said masts for transmittingmovement to said element immediately upon engagement of the airplane-carried hook with said portion of the loop.

5. In an airplane pick-up mechanism, a catapult having an article receiving carriage, a flexible element connected to. an article on the carriage and having a loop, a pair of spaced supports having their upper ends spaced a substantial distance above the ground and provided with slots to releasably receive said loop to support a portion thereof substantially transversely of the direction of movement of an airplane having a hook engageable with such portion of the loop, an; element'operatively' connected to said catapult and movable to render said catapult operative for projecting the carriage, and a cord connected at one end to said element and at its opposite end to said portion of the loop approximately midway between the upper ends of said supports.

6. In an airplane pick-up mechanism, a. catapult having an article receiving; carriage, a hex: ible element connected to an article on the carriage andhaving a loop, a pair of spaced supports having; their-upper ends: spaced a substantial distance above the ground andprovided with slots to releasably receive said loop-to support a portion thereof substantially transversely of the directionof movement of an airplane having a hook engageablewith such portion of the loop, a lever, meanshaving a portion engaged by said lever and controlled by said lever for rendering the catapult inoperative and releasable upon swinging movement of said lever for rendering the catapult operative for projecting said carriage, and a flexible element connected between said lever and said portion of the loop, said last named flexible element being normally maintained" relatively straight whereby initial engagement .of the airplane-carried hook with; said portion of the loop will swing said lever.

'Z. In: an airplane pick up. mechanism, a catapult having an article receiving carriage, a flexible element connected to an article on the cartrolling operation of said catapult, an element engaging. and controlling said clutch device to. maintain said catapult normally inoperative and movable to control said clutch device to. render the catapult operative for projecting the carriage,

and a flexible element normally arranged relatively straight, and directly connected between said element and said. portion of the loop sub.- stantially centrally of the length thereof to move said elementv immediately upon engagement of said portion of the loop by the airplane-carried hook.

8. In an airplane pick-up mechanism, a catapult having an article receiving carriage, a flexible element connectedv to an article on the carriage and having a loop, a pair of spaced supports having their upper ends spaced a substantial distance above the ground and provided with slots to releasably receive said loop to support a portion thereof substantially transversely of the direction of movement of an airplane having a hook engageable with such portion of the loop, a clutch device comprising a pair of clutch elements, a member having connection with said catapult and engageable by said clutch elements to render the catapult inoperative, a lever normally arranged in a position engaging one clutch element to maintain said clutch device elfective for holding said member, said lever being movable to release said first mentioned clutch element and thus release said member from said clutch deviceto render the catapult effective for projecting the carriage, and a flexible element normally arranged in a relatively straight line and directly connected. between said lever and said portion of the loop substantially centrally of the length thereof.

9. In an airplane pick-up mechanism, a. catapult comprising a carriage, a source of power normally conditioned totend to move said carriage, and a latch normally engaging and holding said carriage against movement, a flexible element connected to an article on the carriage and having a loop, means for supporting said loop in open formation with a portion thereof extending transversely of the direction of movement of said carriage to be engaged by a hook carried by an airplane traveling over said catapult in said direction, an element movable to extending transversely of the direction of movement of said carriage to be engaged by a hook carried by an airplane traveling over said catapult in said direction, means tending to release said latch, a lever having one end operative for preventing such means from releasing the latch, and a flexible substantially straight-line connection between said lever and said portion of the loop substantially centrally of the length thereof for turning said lever immediately upon engagement of said portion of the loop by the airplanecarried hook to render said last named means operative for releasing said latch.

11. In an airplane pick-up mechanism, a catapult comprising a carriage, a source of power normally conditioned to tend to move said carriage, and a latch normally engaging and holding said carriage against movement, a flexible element having a loop, means for supporting said loop in open formation with a portion thereof extending transversely of the direction of movement of said carriage to be engaged by a hook carried by an airplane traveling over said cata pult in said direction, a member operative to release said latch, a spring tending to move said member in a latch-releasing direction, a lever normally arranged in a position to prevent a latch releasing movement of said member, and a flexible substantially straight-line connection between said lever and said portion of the loop substantially centrally of the length thereof whereby initial engagement of the airplane-carried hook with said portion of the loop will turn said lever and release said member for a latchreleasing movement.

12. In an airplane pick-up mechanism, a catapult comprising a carriage, a sourc of power normally conditioned to tend to move said carriage, and a latch normally engaging and holding said carriage against movement, a flexible element having a loop, means for supporting said loop in open formation with a portion thereof extending transversely of the direction of movement of said carriage to be engaged by a hook carried by an airplane traveling over said cata pult in said direction, a member having mechanical connection with said latch, a spring urging said member in a latch-releasing direction, a clutch device engageable with said member to prevent a latch-releasing movement thereof, a lever engaging a portion of said clutch device to render it efiective for holding said member against movement, and a flexible element connected between said lever and said portion of the loop substantially centrally of the length thereol whereby initial engagement of the airplane-carried hook will turn said lever and release said clutch device to permit said spring to move said member in a latch-releasing direction.

EDWARD G. HILL.

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