Support plank-based external aircraft cargo carrying apparatus
BACKGROUND OF THE INVENTION 
     The present invention generally relates to aircraft armament apparatus and, in a preferred embodiment thereof, more particularly relates to a support plank-based aircraft armament mounting system incorporating thereon apparatus for supporting various aircraft cargo externally of the aircraft. 
     The external mounting on aircraft of weaponry such as machine guns, rocket launchers and the like, particularly in retrofit applications, has heretofore carried with it a variety of structural, operational and safety limitations and disadvantages. As but one example, the external mounting of machine guns on a helicopter has previously entailed securing an outwardly projecting metal support tube to the helicopter and then mounting the gun on the tube. While this seems to be a fairly straightforward approach, unavoidable limberness in the support tube often led to firing inaccuracies in the mounted gun due to wobbling of its firing axis relative to the aircraft. 
     To a great extent these problems have been eliminated by using the honeycombed metal support plank structure illustrated and described in U.S. Pat. No. 5,024,138 to Sanderson et al. This support plank structure is transversely insertable through the cabin portion of the aircraft in a manner such that a longitudinally central portion of the support plank is disposed within the cabin area, and outer end portions of the plank project outwardly from opposite sides of the body of the aircraft. The central plank portion within the cabin area is removably anchored to the aircraft (which may be a helicopter or a fixed wing aircraft) and outer tip portions of the plank are vertically pivotable, along plank structure hinge lines, between fully extended positions and upwardly and inwardly folded transport or storage positions. 
     At the outer ends of these foldable tip portions are downwardly projecting outboard weaponry mounting structures which, using conventional bomb lug connector apparatus, are operative to removably support a pair of multiple tube rocket launchers at their bottom ends. Mounted on the undersides of the outwardly projecting plank end portions, inwardly of the foldable plank tips, are a pair of inboard support structures operative to removably support a pair of machine guns such as 7.62 mm &#34;mini guns&#34;. 
     While the support plank-based aircraft armament system illustrated and described in U.S. Pat. No. 5,024,138 has proven to be structurally superior to metal tube-type weaponry support systems, the central portion of the support plank, together with the ammunition magazines mounted on the top side thereof, occupies a considerable amount of space in the aircraft cabin area through which the plank extends. This, in turn substantially reduces the amount of cargo that may be carried within the cabin area. In view of this, it would be desirable to provide the aircraft with additional cargo carrying space to compensate for at least some of cabin space lost due to the presence of the central plank section, and its associated ammunition magazines, therein. It is accordingly an object of the present invention to provide such additional cargo carrying space. 
     SUMMARY OF THE INVENTION 
     In carrying out principles of the present invention, in accordance with a preferred embodiment thereof, support plank-based armament apparatus is provided for an aircraft having a cabin area and comprises an elongated support plank member having a longitudinally central portion positioned between opposite end portions of the support plank member. 
     First means are provided for securing the longitudinally central portion of the support plank member to the aircraft, within the cabin area thereof, in a manner such that the opposite support plank member end portions project outwardly beyond opposite sides of the aircraft with first and second side edges of each of the opposite end portions respectively facing the front and rear ends of the aircraft. Second means are provided for operatively mounting weaponry, representatively 7.62 mm mini machine guns, 0.50 caliber machine guns, or 40 mm machine guns, on the opposite support member end portions. 
     In order to compensate for the loss of cabin area cargo space due to the central plank portion and its associated mounting structure disposed within the cabin area, third means are provided for supporting cargo on the outer support plank member end portions. For each of the outer support plank member end portions the third means include (1) first and second auxiliary plank sections each having top and bottom sides, (2) mounting means for removably securing each of the first and second auxiliary plank sections to a different one of the first and second side edges of the outer support plank member end portion for pivotal movement relative thereto between a cargo carrying orientation in which the auxiliary plank section horizontally extends transversely to the outer support plank member end portion, and a folded orientation in which the auxiliary plank section is pivoted upwardly onto the top side of the outer support plank member end portion, with its top side facing upwardly to form a support surface upon which a cargo item may be placed and secured, and (3) locking means for releasably locking each of the first and second auxiliary plank sections in its cargo carrying orientation. 
     In this preferred embodiment of the armament apparatus, means are also provided for releasably securing cargo items on the support surfaces of each of the first and second auxiliary plank sections at the opposite ends of the support plank member when the auxiliary plank sections are in their cargo carrying orientations. Representatively, these means for releasably securing cargo items include pluralities of tie-down eyes formed on opposite sides edges of each of the auxiliary plank sections, and elongated tie-down members extendable over cargo items carried on the auxiliary plank section support surfaces and connectable at their opposite ends to the tie-down eyes. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a phantomed perspective view of a front end portion of an aircraft, representatively a helicopter, having a cabin area through which an armament support plank transversely extends, the support plank having on outer end portions thereof specially designed external cargo carrying structures embodying principles of the present invention; 
     FIG. 2 is an enlarged scale perspective view of one of the support plank outer end portions and the cargo carrying structures mounted thereon; 
     FIG. 3 is an exploded perspective view of the outer support plank end portion and a representative 7.62 mm &#34;mini&#34; machine mounted thereon, with a portion of the cargo carrying structure being pivoted onto the top side of the outer support plank end portion; and 
     FIG. 4 is an enlarged scale outer end view of the outer support plank end portion as shown in FIG. 2, with representative cargo being operatively supported on its cargo carrying structure. 
    
    
     DETAILED DESCRIPTION 
     Referring initially to FIGS. 1 and 3, the present invention provides improved armament apparatus 10 which is operatively connected to a representative helicopter 12 having a cockpit area 14, with doors 15, positioned forwardly of a cabin area 16 having door openings 18. The armament apparatus 10 includes an elongated metal support plank member 20 which is longitudinally extended transversely through the cabin area 16, through the door openings 18, and has a central longitudinal portion 22 which is anchored to the floor of the cabin area 16. With the unique exceptions noted below, the support plank 20 is similar to the support plank illustrated and described in U.S. Pat. No. 5,024,138 which is hereby incorporated by reference herein. 
     Outer end portions 24 of the support plank 20 project outwardly from opposite sides of the helicopter body and have, on their outer end corners, mounting lug pairs 26,28. These lug pairs are mateable with corresponding lug pairs on outer tip sections of the plank (not shown) to pivotally mount the tip sections on the outer end portions 24 of the plank 20 as illustrated and described in U.S. Pat. No. 5,024,138. 
     As subsequently described herein, a pair of 7.62 mm &#34;mini&#34; machine guns 30 (only one of which is shown in FIG. 3) are removably mounted on the undersides of the outer plank end portions 24. Alternatively, 0.50 caliber machine guns, 40 mm machine guns, or other types of weaponry could be mounted on the plank end portions 24. The mounted machine guns 30 are supplied with belted ammunition (not shown) from two ammunition magazine boxes 32 secured to the top side of the intermediate plank portion 22 within the cabin area 16 and illustrated in phantom in FIG. 4. Belted ammunition from the magazine boxes 32 is passed downwardly through a pair of rectangular openings 34 formed in the outer plank end portions 24 and then appropriately routed to the machine guns depending from the outer plank end portions 24 outboard of the plank openings 34. 
     As can be seen in FIG. 4, the plank 20 and its associated ammunition magazine boxes 32 occupy a considerable space within the cabin area 16--space that could otherwise be used to carry various cargo within the helicopter 12. The present invention uniquely compensates for this loss of interior cargo space by incorporating in the overall armament support plank structure 20 auxiliary apparatus for externally supporting cargo. 
     As illustrated in FIGS. 1-4, this auxiliary cargo support apparatus includes, at each of the opposite ends of the illustrated plank structure 20, a pair of elongated rectangular auxiliary metal plank sections 36,38. In a manner subsequently described, the auxiliary plank sections 36,38 are removably secured at inner ends thereof to front and rear side edge portions of the outer plank end portions 24, outboard of the plank openings 34, and longitudinally extend transversely to the plank 20. The auxiliary plank sections 36 and 38, which are disposed externally of the helicopter on opposite sides thereof, may be locked in their cargo support orientations shown in FIGS. 1, 2 and 4, and may also be selectively pivoted (one at a time) upwardly onto the top side of their associated outer plank end portion 24. For example, as illustrated in FIG. 3, either of the forwardly projecting auxiliary plank sections 36 may be upwardly pivoted in this manner to provide access to the adjacent cockpit door 15. 
     Referring now to FIGS. 2 and 3, to pivotally mount the auxiliary plank sections 36,38 on the outer plank end portions 24, spaced apart inboard and outboard mounting lug structures 40,42 are formed on the front and rear side edges of the outer plank end portions 24 outboard of the plank openings 34. Each of the lug structures 40,42 has an upper yoke portion 44, and a base portion 46 from which a tab section 48 outwardly projects. Pairs of mounting lugs 50,52 are formed on the inner end corners of each of the auxiliary plank sections 36,38 with each of the lug pairs 50,52 receiving and being pivotally secured to one end of a pivot member 54 by a pin 56. The opposite end of each pivot member 54 is received in one of the yoke portions 44 and pivotally secured therein by a retaining pin 58. 
     Each of the mounting lug pairs 50 and 52 have an aligned pair of circular holes 60 therein (see FIG. 3). When the auxiliary plank sections 36 and 38 are downwardly pivoted to their FIG. 2 cargo carrying orientation the tab sections 48 are received between the lug pairs 50 and 52, and the holes 60 in each of the lug pairs 50 and 52 are aligned with a circular hole 62 in their associated tab section 48. The auxiliary plank sections 36 and 38 may then be locked in place using retaining pins 64 (see FIGS. 3 and 4) inserted through the adjacent hole sets 60 and 62. 
     Any of the auxiliary plank sections 36 and 38 may be pivoted upwardly onto the top side of its associated outer plank end portion 24, as illustrated in FIG. 3) simply by removing its retaining pins 64. If desired, any of the auxiliary plank sections 36,38 may be removed from its associated outer plank end portion 24 by additionally removing the pins 58. 
     As illustrated in FIG. 4, with the auxiliary plank sections 36,38 pivoted downwardly to and locked in their outwardly projecting cargo carrying orientations, cargo such as the representatively illustrated cargo boxes 66,68 may be respectively placed atop the plank sections 36,38. A spaced pair of mounting eyes 70 are formed on the outboard side edge of each of the auxiliary plank sections 36 and 38, and a spaced pair of mounting eyes 72 are formed on the inboard side edge of each of the auxiliary plank sections. To releasably secure the cargo boxes 66,68 atop the auxiliary plank sections 36,38 elastomeric tie-down straps 74 are stretched over the tops of the boxes 66,68 as illustrated in FIG. 4 and secured at their opposite ends to the outboard and inboard mounting eyes 70,72. 
     As can be seen, the addition of the auxiliary plank sections 36,38 to the overall armament support plank structure permits the plank structure to provide external cargo carrying space compensating for the reduction in cabin area cargo storage space created by the presence within the cabin area of the central plank section 22 and its associated ammunition magazine boxes 32. While the improved plank structure of the present invention has been representatively illustrated as being incorporated in a helicopter, it will be readily appreciated that it also could be advantageously be incorporated in other types of aircraft such as a fixed wing aircraft. 
     According to another feature of the present invention, the means for releasably and pivotally securing the auxiliary plank sections 36,38 to the forward and rear side edges of the outer plank end portions 24 also are used as part of mounting means for releasably supporting the illustrated machine gun 30 (or other weaponry) on the underside of the outer plank end portions 24. These mounting means include a deck plate structure 76 (see FIG. 4) secured to the top side of the gun 30 and having spaced pairs of upwardly projecting mounting lugs 78,80 respectively formed on its outboard and inboard sides and having circular openings 82 extending therethrough; circular openings 84 formed in the yoke base portions 46 inwardly of their tab sections 48; and intermediate mounting lugs 86 formed on the forward and rear side edges of each outer plank end portion 24 between the inboard and outboard mounting lug structures 40,42 thereon. 
     Illustratively, the machine gun 30 shown in FIG. 3 is removably secured to the underside of the depicted outer plank end portion 24 by positioning the intermediate mounting lugs 86 on the front and rear side edges of the plank end portion 24 respectively between the forward and rear lug pairs 80 of the deck plate 76; positioning the forward and rear side yoke bases 46 respectively between the forward and rear lug pairs 78 of the deck plate; and then anchoring the deck plate 76 in place by inserting retainer pins (not shown) through the hole sets 82,84 and 82,88. Alternatively, the deck plate lug pairs 78,80 could be connected to the inboard lug structures 40 and the intermediate lugs 86 to mount the machine gun 30 somewhat closer to the side of the helicopter body if desired. 
     The foregoing detailed description is to be clearly understood as being given by way of illustration and example only, the spirit and scope of the present invention being limited solely by the appended claims.