with continued reference to the drawings , the ammunition supply system of the present invention includes a vehicle 20 having a chassis or frame 21 supported by ground - engaging wheels 22 . such vehicle may be propelled and steered in any conventional manner ( not shown ) such as by a self - contained power plant , by a separate propelling vehicle , or by an elongated tongue which may be pulled by several people . the vehicle 20 is moved to a position adjacent to an armament system such as a military aircraft 23 ( fig2 ) and an ammunition supply , which normally includes at least two ammunition boxes or containers 24 , is moved to a position adjacent to the rear end of the vehicle 20 . if desired , the supply of ammunition may include a transport vehicle 25 on which a plurality of ammunition containers are mounted . one of the containers 24 normally is empty while the remaining containers are filled with ammunition carried by an elongated belt 26 of indefinite length . it is not essential that the containers 24 be in parallel abutting relationship with each other , however , such containers should be in proximity to each other . as illustrated best in fig1 , each ammunition belt 26 includes a plurality of tubular members 27 of a size to receive a shell or round of ammunition 28 of an appropriate caliber such as 20 mm to 40 mm . each tubular member includes a relatively deep cam engaging groove 29 adjacent to one end and includes a pair of relatively shallow annular grooves 30 intermediate its ends . the annular grooves 30 receive loops or closed bands 31 of flexible substantially non - stretchable material and preferably such loops ordinarily are interwined with each other at each tubular member . each of the loops includes a semicircular portion at each end which is disposed partially around one of the tubular members and such semicircular portions are joined by connecting portions which extend to an adjacent tubular member in such a manner that the tubular members are in spaced generally parallel relationship with each other . however , due to the flexibility of the loops , such tubular members may be moved toward each other to provide slack in the loops after which such tubular members may be moved axially a limited amount relative to each other for a purpose which will be described later . in order to remove the ammunition belt 26 from a container 24 , a main housing 33 is mounted on the frame of the vehicle 20 . a platform 34 is mounted on top of the main housing and such platform is movably mounted in any described manner as by rollers or the like within tracks 35 to permit the platform to be moved longitudinally of the vehicle . an upright post 36 is fixed to the central portion of the platform 34 and rotatably receives a sleeve 37 on which a boom 38 is pivotally mounted . the boom 38 normally is of a length such that the outer end ( or end remote from the sleeve 37 ) extends beyond the rear end of the housing 33 . an adjustable support arm 39 having a resilient portion intermediate its ends connects the outer end of the boom 38 to the upper end of the sleeve 37 to permit limited vertical movement of the outer end of the boom . such outer end of the boom 38 is connected by a link 40 to a container interface unit 41 so that such container interface unit may be located above and in spaced relationship to a pair of ammunition boxes 24 . with particular reference to fig5 - 7 , the container interface unit 41 includes a housing 42 having a shaft 43 extending transversely across the same and generally centrally thereof . one end of the shaft 43 is drivingly connected to a gear box 44 which is driven by a flexible shaft 45 from any convenient source of power such a power plant on the aircraft 23 . within the housing 42 , a first belt drive wheel 46 is located adjacent to one side of the housing and is keyed or otherwise attached to the shaft 43 so that when the shaft is driven in the direction of the arrow 46 ( fig6 ), the ammunition belt 26 is pulled from the main housing 33 and is discharged along an inclined wall 48 into an empty ammunition box or container 24 . the end of the shaft 43 remote from the gear box 44 is keyed or otherwise attached to a reversing gear mechanism 49 which meshes with a driven gear 50 carried by a sleeve 51 . the sleeve 51 is rotatably mounted on the shaft 43 by low friction bearings 52 and the outer periphery of such sleeve is keyed or otherwise attached to a second belt drive wheel 53 . an ammunition belt 26 is threaded onto the belt drive wheel 53 from the filled ammunition box 24 so that the belt is removed from the box by such wheel . it is noted that the belt drive wheels 46 and 53 rotate in opposite directions at substantially the same speed so that the belt is removed from one ammunition box and passes through the housing 33 after which such belt is discharged into another ammunition box in a manner which will be described later . a pair of flexible chutes 54 and 55 are connected in side - by - side relationship to the container interface unit 41 with the flexible chute 54 being substantially in alignment with the belt drive wheel 46 and the flexible chute 55 being substantially in alignment with the belt drive wheel 53 . as illustrated best in fig2 and 3 , the flexible chutes 54 and 55 curve downwardly from a position in side - by - side relationshiop on the container interface unit 41 to a position in which the flexible chute 55 is located above and in spaced relationship to the flexible chute 54 and both chutes are connected to the rear wall of the main housing 33 . within the main housing 33 a rear interface unit 58 is provided substantially in alignment with the flexible chutes 54 and 55 . such rear interface unit includes a pair of side walls 59 each of which is provided with a groove 60 having straight and curved portions in the upper portion of each side wall and such groove is substantially in alignment with an opening 61 in the rear wall of the housing 33 . the inlet chute 55 is attached to the rear wall of the housing in alignment with the opening 61 so that the ammunition belt 26 passing through the flexible chute is discharged from the chute into the groove 60 . additionally a groove 62 having straight and curved portions is provided in each of the side walls 59 in spaced relationship to the grooves 60 and each of the grooves 62 is generally in alignment with an opening 63 in the rear wall of the housing 33 . the flexible chute 54 is attached to the rear wall of the housing substantially in alignment with the opening 63 and is adapted to receive an ammunition belt from the housing . a drum 64 having a relatively large diameter is rotatably mounted on a shaft 65 within the housing 33 and such drum may be driven in any desired manner from a convenient power plant such as a gear box 66 driven by the flexible shaft 45 from the aircraft power plant . such drum includes a plurality of continguous flutes or cradles 67 extending from side to side thereof and preferably several annular grooves 68 are disposed about the periphery of the drum adjacent to one end . in order to transfer the ammunition belt from the upper portion of the rear interface unit 58 to the drum 64 and from the drum to the lower portion of the rear interface unit , such rear interface unit includes a drive sprocket 69 mounted on a shaft 70 rotatably carried by the side walls 59 . as illustrated best in fig8 the drive sprocket 69 is of a size to extend between the grooves 60 and 62 in the side walls 59 . the shaft 70 of the rear interface unit 58 is driven by a gear train 71 connected to a gear box 72 which in turn is driven from a convenient source of power such as the flexible shaft 45 . the drive sprocket 69 pulls the belt 26 through the chute 55 substantially at a fixed speed with the loops 31 which connect the tubular members being spaced apart a predetermined distance . a pair of upper and lower star wheels 73 and 74 are mounted on shafts 75 and 76 , respectively , within the rear interface unit 58 . one end of each of the shafts 75 and 76 is provided with a gear 77 which meshes with a gear 78 affixed to the shaft 70 so that rotation of the shafts 75 and 76 and the star wheels 73 and 74 carried thereby are synchronized with the rotation of the drive sprocket 69 . the upper star wheel 73 is positioned to remove the tubular members 27 of the belt from the drive sprocket , while such tubular members are guided by the grooves 60 . the teeth of such upper star wheel are closer together than the teeth of the drive sprocket so that the distance between the tubular members 27 is reduced after the tubular members are removed from the drive sprocket which provides slack in the loops 31 . each of the side walls 59 of the rear interface unit is provided with an outwardly extending y - shaped head and the outwardly extending arms of such head are disposed within the annular grooves 68 of the drum 64 . as illustrated best in fig8 the y - shaped head forms an extension of the inner surfaces of the grooves 60 and 62 so that the head functions as a guide member for transferring the tubular members to the flutes or cradles of the drum . it is noted that the speed of rotation of the drum is synchronized with the rotation of the upper star wheel so that one of the tubular members 27 is placed in each flute 67 of the drum with the loops 31 being slack . with particular reference to fig4 and 10 , a segmental retaining member 80 is mounted on the side wall of the main housing 33 and the upper portion of such retaining member extends from one side of the drum to the other . the retaining member 80 includes a downwardly extending flange 81 located in spaced relationship with the periphery of the drum 64 and in a position to engage the extractor groove 82 which is located adjacent one end of each of the shells 28 . when the ammunition belt 26 is placed on the drum by the rear interface unit , the extractor grooves 82 of the shells 28 engage the flange 81 so that the shells travel in a relatively straight path of movement around the upper portion of the drum . an arcuate cam bar 85 is mounted within the housing 33 in spaced relationship to the drum 64 and such cam bar has one end located adjacent to the upper portion of the rear interface unit 59 . the main portion of the cam bar extends substantially entirely around the drum so that the opposite end terminates adjacent to the lower groove 62 of the rear interface unit . spaced from and generally parallel with the cam bar 85 is a hold - down bar 86 which engages the tubular members 27 and retains such members within the flutes or cradles 67 of the drum . the end of the cam bar 85 adjacent to the rear interface unit is substantially in alignment with the reduced groove 29 of the tubular members 27 so that such cam bar is disposed within the grooves as the drum carries the tubular members through the housing . during the rotation of the drum , the edges of the grooves 29 of the tubular members engage the cam bar 85 and cause the tubular members to be moved axially away from the shells 28 during the first portion of rotation of the drum so that the shells are entirely free of the tubular members and such shells are supported within the flutes 67 of the drum by the flange 81 of the retainer bar 80 . if desired , a hold - down bar ( not shown ) may be provided to assist in retaining the shells 28 within the flutes . a front interface unit 87 is mounted within the housing 33 on the side of the drum opposite the rear interface unit and such front interface unit includes a pair of side walls 88 ( fig9 ). a shaft 89 is rotatably carried by the side walls 88 and such shaft is adapted to be driven in any desired manner , as by a gear train 90 which in turn is driven from any convenient source of power such as a gear box 91 connected to the flexible shaft 45 to cause the shaft 89 to be rotated in timed relationship with the shaft 65 of the drum and the shaft 70 of the rear interface unit . intermediate the side walls 88 of the front interface unit , one or more drive sprockets 92 are keyed or otherwise attached to the shaft 89 and such drive sprockets receive and drive an element conveyor 93 . the conveyor 93 is of conventional construction and includes a plurality of cradles 94 of a size to clampingly receive the casings of the shells 28 . the front interface unit 87 includes a pair of y - shaped partitions 95 the arms of which are slidably mounted within the annular grooves 68 of the drum and function as guides for removing the shells 28 from the flutes or cradles 67 of the drum . it is noted that the upper retaining bar 80 terminates in the area of the front interface unit . a pair of upper and lower star wheels 96 and 97 are mounted on shafts 98 and 99 , respectively , which are rotatably carried by the side walls 88 . in order to drive the star wheels 96 and 97 , each of the shafts 98 and 99 is provided with a gear 100 which meshes with a gear 101 attached to the shaft 89 so that the star wheels 96 and 97 are driven in timed relationship with the drive sprockets 92 and the drum 64 . the upper star wheels 96 are adapted to engage the casings of the shells 28 while the shells are still carried by the drum 64 and move such shells along the partition 95 until they are subsequently inserted into the cradles 94 of the element conveyor . in order to remove the shells 28 from the main housing 33 , the front wall of such housing is provided with a pair of vertically spaced openings 102 and 103 for the egress and ingress of the element conveyor 93 . an auxiliary housing 104 is mounted on the front wall of the main housing in a position surrounding the openings 102 and 103 and such auxiliary housing may include a window or transparent panel 105 which serves as an inspection station . the opposite end of the auxiliary housing is connected by a pair of flexible chutes 106 and 107 to an aircraft interface unit or load head 108 of conventional construction . the element conveyor 93 carries live shells through the flexible chute 106 to the aircraft interface unit 108 which is located in proximity to the armament system of the aircraft . within the aircraft interface unit the shells are removed from the element conveyor and are inserted into the aircraft armament system , while simultaneously empty shell casings and misfired rounds are removed from the aircraft armament system and are inserted into the cradles 94 of the element conveyor for return to the main housing 33 . the aircraft interface unit may be supported in a position contiguous to the armament system of the aircraft in any desired manner , such as by mounting the interface unit on one end of a counterbalanced beam which is attached to a universal pivot carried by the frame 21 . as illustrated , an elongated tongue 109 is pivotally connected to the frame 21 and the outer end of such tongue is provided with a generally vertically disposed sleeve 110 which slidably receives one end of a support rod 111 . the opposite end of the support rod is connected to the aircraft interface unit 108 in any desired manner , as by welding or the like . a fluid cylinder 112 is carried by the sleeve 110 and such cylinder has a piston rod 113 the outer end of which is attached to the support rod 111 so that operation of the cylinder 112 causes the support rod 111 and the aircraft interface unit 108 to be raised and lowered . when the element conveyor 93 returns the empty shell casings and misfired rounds to the front interface unit 87 , the lower star wheel 97 removes the same from the cradles 94 and carries such shell casings along the y - shaped partitions 95 and places such casings on the cradles 67 of the drum 64 . the second portion of the segmental retaining bar 80 is disposed below the drum in a position that the flange 81 engages the extractor grooves of the shells so that the shells and misfired rounds travel in a relatively straight path of movement around the lower portion of the drum . if desired , a support bar ( not shown ) may be provided along the lower portion of the drum to retain the shell casings within the flutes or cradles 67 . after the shell casings have been placed on the cradle of the drum , the drum continues to rotate . at the lower portion of the drum the cam bar 85 engages the reduced groove 29 of the tubular members and causes such tubular members to move axially of the cradles 67 . since the shell casing and misfired rounds are in axial alignment with the tubular members 27 , such shells and misfired rounds are received within the tubular members . thereafter the lower star wheel 74 of the rear interface unit removes the belt 26 from the drum 64 , after which the belt drive wheel 46 pulls the belt through the flexible chute 54 and discharges the same into an empty ammunition box . preferably one or more persons may arrange the belt in layers within the box as the belt is being discharged . it will be understood that when the type of ammunition in the aircraft armament system is to be changed , the same procedure as described above is followed until an entire complement of shells is uploaded into the aircraft while empty shell casings , misfired rounds and unfired rounds are downloaded therefrom .