Patent Publication Number: US-10330449-B2

Title: Dispenser and dispensing system for radar jamming material

Description:
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH 
     This invention was made with Government support under Contract No. H94003-04-D-0006 awarded by the United States Department of Defense. The Government has certain rights in this invention. 
    
    
     FIELD 
     This invention relates to systems for in-flight dispensing and cutting of adversarial radar area suppression and countermeasure materials, such as chaff dipole elements, for the protection of aerial vehicles against guided missiles and other radar-based weaponry. 
     BACKGROUND 
     Controllably deployable area suppression and countermeasure materials of several types are used to deter and defeat attacks on aircraft by other aircraft, missiles, and antiaircraft artillery. In each case, the material is deployed by an aircraft to confuse an attacker, and specifically the sensor used by the attacker, creating a radar-jamming cloud. 
     A conventional method for the self-protection of aircraft and the like from radar-guided missiles employs a chaff dispenser for ejecting chaff material in the form of pre-cut dipoles, or lengths of reflective or absorptive materials such as metallized glass or graphite fibers, into the airstream immediately along the flight path of the aerial vehicle. One or more cartridges containing dipoles of a length selected in accordance with an expected radar frequency are fired from the dispensing device into the airstream where there is formed a cloud, or bloom, of the chaff which spoofs the radar and thereby provides protection of the vehicle. 
     Some chaff dispensing systems have been employed that cut chaff dipoles in-flight, but they typically are bulky, heavy and have a relatively slow response time. Chaff bundles typically have round or elliptical cross sections, and they are typically loaded into dispensing systems with their long axes oriented vertically. Chaff rovings are unspooled from the center of the bundle for chopping into desired lengths by the cutter during dispensing operations. The vertical orientation often results, due to a roving bundle&#39;s weight (e.g., approximately 50 pounds for common roving bundles) in compression forces that cause the roving bundle to lose its structural support leading to spooling jams when the chaff may be critically needed. Vertical stacking of multiple chaff bundles on top of one another would only exacerbate this fault mode. 
     Thus, conventional in-flight chaff dispensing systems present a number of problems, and an improved self-protection device has been needed for some time. Therefore, the device of the present invention has been developed to overcome problems associated with such conventional chaff dispensing systems. 
     SUMMARY OF THE INVENTION 
     The apparatus and systems described herein are directed to material dispensing applications, designed to minimize jams in unspooling countermeasure and/or area suppression material, such as chaff rovings. The implementations are configured to store for dispensing spools or bundles of the material horizontally with respect to the vehicle in or on which they are mounted, and with respect to ground and normal to the Earth&#39;s gravitational force. One or more material bundle may be mounted on a horizontal support rod, from which the materials may be unspooled, reducing jam frequency and making easier dispensing to a cutting mechanism. 
     In one aspect, the implementations provide a dispensing unit for area suppression and countermeasure materials, including a dispensing canister and a support structure. Each canister may have a first end, a second end having a central axis extending to the first end, a support rod extending at least between the first end and the second end along the central axis, and a wall defining a canister cavity. The support rod may be rotatably engaged with the first end, such that one or the other may spin during material deployment. The wall extends circumferentially around the support rod from the first end to the second end. The canister may be dimensioned to house the rod and at least one material bundle loaded thereupon having a long dimension aligned with the central axis. The first end may have an aperture large enough for material roving to pass through. The canister&#39;s position is stably fixed by the support structure, such that the support rod is maintained during material deployment in a horizontal position, parallel to ground and normal with respect to gravitational forces. The canister and support structure cooperate to make the canister cavity easily accessible for re-loading countermeasure material, however single-use canisters are within the scope of the invention. 
     In certain implementations, the dispenser is configured with a plurality of canisters, which may be arranged lengthwise parallel to a central horizontal axis of the dispenser. Each of the canisters may be supported on a rack unit comprised of one or more plates spaced apart from one another and each including a bore hole to accommodate an associated canister. The canisters may be permanently affixed to, or releasable from, the rack unit. The material may be loaded into the canisters while the canisters are supported by the rack unit, or after removal from the rack unit. 
     Both ends of the canister may be rotatably engaged with the support rod, or just the first end. The support rod may terminate at, or traverse, the ends. In some implementations, the rod may be connected to the second end in a fixed manner, in which case the second end and rod rotate together with respect to the first end, or vice versa. One or both of the ends may comprise end caps including bearings facilitating the respective rotational relationships. 
     Implementations also provide a material dispensing system comprised of the dispenser described above, operably engaged with a material roving cutting unit. The cutting unit may be motorized to draw material rovings from one or more canisters in the dispensing unit. As a result of the winding design typical of area suppression and countermeasure materials, such as chaff bundles, the unspooling force exerted by the cutting unit to draw the roving translates into rotational forces on the chaff bundles and results in a rotational spin of either the rod bearing the weight of the chaff bundle, or each canister end having an aperture through which the roving is being drawn. The tensile strength of commercially available area suppression and countermeasure materials is sufficient such that the materials will not break under such unspooling forces. 
     The cutting unit may include a rotatable cutting head configured with one or more blades disposed across a surface of the cutting head, the blades being spaced apart so as to cut the drawn roving(s) into desired lengths. The cutting head is disposed adjacent to a rotatable roller such, when the cutting head and roller are rotating, a surface of the roller periodically comes into contact with the respective edges of the cutting head blades in order to cut threaded rovings into desired lengths. A drive structure operably engaged with the cutting head and roller provides rotational motive forces sufficient to draw the rovings there between and to cut the rovings into desired lengths. Cutting heads with distinct spacing of cutting blades may be interchanged into the cutting unit, so the lengths into which the rovings will be cut may be selectable. Certain implementations may be further configured with a support rod drive structure, synchronized with the cutting unit, for assisting in providing rotational forces to the support rod bearing the weight of the material bundle. 
     Other objects and advantages of the implementations described herein will be apparent from the following description and appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further advantages and features of the invention can be derived from the following detailed description of exemplary embodiments of the invention, with reference to the drawings. 
         FIG. 1  is a perspective view illustrating an implementation of the dispensing system, in an example mounting configuration within the fuselage of an aircraft; 
         FIG. 2  is a perspective view illustrating an implementation of a dispensing unit, in an example mounting configuration in a housing mounted on an aircraft wing, wherein a dispensing system housing and aircraft wing are cut away; 
         FIG. 3  is an illustration of an embodiment of a dispensing unit, isolated from the dispensing system; 
         FIGS. 4A-4C  are exploded and axial views of an embodiment of a dispenser canister; and 
         FIG. 5  is a sectional end view of an embodiment of a cutting unit and its interface with an end of the dispensing unit. 
     
    
    
     DETAILED DESCRIPTION 
     The implementations described herein are directed to dispensing systems particularly useful for in-flight cutting and dispensing of area suppression and/or countermeasure materials. Such materials may comprise, but are not limited to, “chaff”, glass fibers or filaments (e.g. 1 mil diameter) coated with electrically conducting aluminum or other suitable metal, or graphite fibers, hot IR chaff, or other materials that provide reflection or absorption of radiofrequency energy sufficient to confuse and divert radar based missiles aimed at the aircraft, or to create a radar-suppressing cloud dispersing and lingering over a wide area. The dispensed material may include any materials that may be cut into discrete segments, sections, particles, or other subdivided form, for dispensing into an environment in which the material may be useful, e.g., for combating measures directed at or against persons, vehicles, installations, etc., or for preemptive area suppression of radar such as might be desirable in conjunction with an aircraft mission. While the implementations are described primarily with reference to area suppression and/or decoy applications in aircraft, and primarily affecting preferred electromagnetic spectra, the utility of the implementations is not thus limited, but extends to a wide variety of other placements and applications. 
     The implementations overcome problems inherent in dispensing systems that store area suppression and countermeasure materials (e.g., chaff bundles) vertically, and allow easy dispensing to a roving cutter. Providing horizontal support for the weight of the roving in a manner that doesn&#39;t interfere with chaff unspooling permits use of longer chaff bundles and/or the use of multiple bundles strung together in a lengthwise fashion. These features permit greater amounts of material to be stored in the dispensing system, and greatly reduce the frequency of unspooling jams. Dispensing systems described herein may be used with existing roving winding designs, which may be comprised of helical or circumferential windings around a central core of a roll or bundle. However, the improvement in load distribution may permit greater amounts of chaff, in bigger or longer bundles, to be developed and employed. Features of the implementations also lend themselves to easier feed access of the roving to the cutter, and re-loading (e.g., standard aircraft automated loaders may be employed for heavier, round or cylindrically-shaped objects.) 
     In  FIG. 1 , a dispensing system  2  according to certain implementations is illustrated within an aircraft fuselage  4 .  FIG. 1  is an axial view of the aircraft fuselage  4  provided with an example hatch  6  representing a pathway through which chopped area suppression and/or countermeasure materials (materials  8 ) may be dispensed. The fuselage  4  may be any aircraft that either might itself be subject to threats from radar, IR or laser sensor-based weaponry (e.g., missiles), or which might be purposed for dispensing a wide-area cloud of radar-suppression capability for the protection of other aircraft. Such weaponry can be fired either from other aircraft or from the ground. The dispensing system  2  may dispense chopped materials  8  from hatch  6 . In the configuration shown, dispensing system  2 , which may be comprised of dispensing unit  10  and cutting unit  12 , is fixedly mounted to or on a support surface  14  within the aircraft (e.g., the floor. However, any mounting configuration (wall, ceiling, bracket, etc.) may be used that maintains a substantially fixed spatial relationship between dispensing unit  10  and cutting unit  12 , and a substantially horizontal orientation for canisters  16  with respect to ground and planetary gravitational force during operation.  FIG. 2  illustrates another potential mounting configuration, in which the dispensing system  2  is housed in a self-contained housing  18  mountable on the underside of an aircraft&#39;s wing  20 . 
     With continued reference to  FIG. 1 , dispensing unit  10  may be operably engaged with cutting unit  12 , which chops the material into desired lengths for dispensing through hatch  6 . The chopped material  8  may be simply released into the airstream, or alternatively ejected by ejection means such as a piston and/or pressurized gas. Hatch  6  may comprise a moveable hatch cover  22  over an opening in the aircraft fuselage  4 . The dispenser  10  and cutting unit  12  are shown supported by a level support surface  14 , proximate hatch  6 , such that each canister  16  for storing dispensing material may be horizontally oriented such that its central axis  24  is substantially parallel with respect to ground and normal with respect to gravitational force (shown as force line  26 .) In an airplane mounted configuration, this would likely mean mounting the dispensing system such that the canister(s)  16  are disposed substantially horizontally in an imaginary plane parallel with the airplane&#39;s wings; 
     A control unit  28  and power supply  30  for providing on-command motive force to the cutting unit  12  may be connected to the dispensing system  2 . The control unit  28  and power supply  30  may be remotely located from the dispensing unit  2  (e.g., the control unit may be located in the cockpit of the aircraft), but are connected to the dispensing system  2  by electrical cables  86 . It is also possible to arrange control unit  28  and power supply  30  as two separate units remote from one another. 
     As shown in  FIG. 3 , a chaff bundle  32  typically comprises a wound roll of material roving  34  having a round or elliptical cross section. The leading or feed end  36  of each strand of material roving  34  may be provided with a thin, flat roving threading tab  38  to facilitate the threading of the roving  34  into cutting unit  12  when the chaff bundle  32  is loaded into a canister  16  of the dispensing unit  10 . Each roving  34  may also be provided with a fastener  40  at its trailing (i.e., non-feed) end  42  permitting the trailing end  42  to be fastened to the feed end  34 ′ of another chaff bundle  32 ′, or the roving ends  34 ′,  42  may simply be tied together. This allows more than one chaff bundle  32 ,  32 ′, and a greater amount of chaff or other material, to be loaded into a canister  16 , and reduces the need to re-load canisters. As shown, dispensing unit  10  may be configured with any number of canisters  16 . Commercially available chaff bundles typically have cross-sectional diameters of approximately 12″, and while such dimensions can be accommodated, the advantageous weight-bearing features of the present invention permits larger dimensioned bundles to be used. 
     With reference to  FIGS. 4A-4C , implementations of canister  16  may have a first end cap  44 , a second end cap  46 , a support rod  48 , and a wall  50  enclosing a cavity  52 . Canister  16  may be dimensioned so as to have sufficient width W and length L to house in its cavity  52  one or more chaff bundles  32  oriented with its long dimension coinciding with the long dimension (L) of canister  16 . Suitable materials for constructing the canisters  16  are characteristically strong and relatively light weight, such as aluminum and/or similar metal materials. In certain implementations, however, where canister  16  may be intended for a single use, it may be composed of a durable, disposable material, such as thick cardboard. The dispenser wall may be made of a relatively thin sheet metal, preferably about ⅛-⅜ inch or more thick, formed by extrusion or molding into the desired shape (shown as cylindrical, but this is not intended to be limited to such shape.)  FIG. 4B  presents an expanded view, and  FIG. 4C  an axial view, of certain implementations of first end cap  44  of canister  16 . First end cap  44  may comprise an end cap that may be fitted, screwed, latched or otherwise reversibly connected to wall  50  to partially define cavity  52 . First end cap  44  includes an aperture  54  disposed therein dimensioned so as to permit area suppression and countermeasure material roving  34  to be drawn from the chaff bundle  32  loaded onto rod  48  in cavity  52 . 
     Support rod  48  extends between first end cap  44  and second end cap  46  along an axis  56  axially traversing the center of the cavity  52  defined by the end caps  44 ,  46  and wall  50 . Support rod  48  has an outer diameter no greater than the diameter of a hollow core of chaff bundle  32 , in order that chaff bundle  32  may be loaded onto support rod  48 . Upon loading, support rod  48  bears the weight of chaff bundle  32 . A fastener (not shown) may be utilized to secure chaff bundle  32  to support rod  48 . Support rod  48  may be rotatably engaged with at least first end cap  44 . In certain embodiments, this may be achieved by the inclusion, in first end cap  44 , of journal or ball bearings  56  configured in a concentric manner and dimensioned so as to receive and permit free rotation of support rod  48  with respect to first end cap  44 . In some embodiments, support rod  48  rotates during material deployment, as a result of material roving  34  being drawn through aperture  54 . The tensile force on roving  34  when it is pulled by the cutting unit causes the roving to unspool from the chaff bundle  32 . Due to the circumferential winding configuration of a chaff bundle  32 , unspooling of roving  34  affects a rotational force (indicated by arrow  58 ) on the chaff bundle  32 . The rotational force on chaff bundle  32  may translate into a rotational force on support rod  48  onto which chaff bundle  32  is loaded, particularly when there exists a secure fit between chaff bundle  32  and support rod  48  due to tight dimensioning and/or fastening. Drawing the roving  34  through aperture  54  while the weight of the chaff bundle  32  is supported by rod  48  eliminates the likelihood of unspooling jams experienced by conventional dispensing systems, wherein the weight of vertically oriented chaff bundles may lead to collapsing of the bundle. 
     Support rod  48  may be similarly rotationally engaged with second end cap  46 . Alternatively, second end cap  46  may rotate with support rod  48 , if it is affixed thereto. The latter configuration may require the additional use of a journal or ball bearings joint between second end cap  46  and canister wall  50  to permit second end cap  46  to rotate. In certain implementations, either or both end caps  44 ,  46  may comprise end caps that are removable from wall  50 . For example, an end cap at second end cap  46  may be removed in order to access to canister cavity  52  to load one or more chaff bundles  32  onto support rod  48 . In other implementations, the canisters  16  may be intended for a single use, so end access for re-loading is optional. 
     With reference to  FIGS. 3 and 5 , the canisters  16  of dispensing unit  10  may be disposed within, or on, a support structure  60 . Any construction may be utilized that has the strength and stability to bear the weight of canisters  16  loaded with material, and which provides easy access to the canister cavity for material loading. For example purposes, support structure  60  is illustrated as rack comprised of three parallel plates  62  (two spoked plates are shown in  FIG. 2 ). In certain implementations, one or both of the canister end caps  44 ,  46  are accessible for removal in order to reload material, while canister  16  is being supported by rack plates  62 . Alternatively, the canisters  16  may be releasably mounted in rack plates  62 , such that they may be removed from the plates when material reloading is required. 
     Each plate  62  may include at least one bore  64  corresponding to a bore  64 ′ in another plate(s). Any number of bores  64  and corresponding canisters  16  may be configured in dispensing unit  10 . The illustrated implementations, for example, present two, seven, and nine-canister configurations, with canisters arranged symmetrically around a central axis  66  and/or central bores  65 ,  65 ′,  65 ″, wherein rack plates  62  each have a corresponding set of bores  64 ,  64 ′,  64 ″ and central bores  65 ,  65 ′,  65 ″. Each bore  64  may be arranged and dimensioned so as to receive and support at least one canister  16 , such that the support rod  48  of canister  16  may be oriented during area suppression and/or countermeasure material deployment substantially horizontally with respect to ground, and normal with respect to gravitational forces. An absolute horizontal orientation of the rods is not a necessity, and may not be possible in circumstances requiring countermeasure deployment (i.e., when an aircraft is attempting to evade radar weaponry.) However, performance of the dispensing system  2  improves when the support rods  48  near horizontal orientation. For clarity,  FIG. 3  illustrates exemplary upward facing dispenser unit mounting surfaces  68  useful in wing-mounted configurations, while  FIG. 5  illustrates exemplary downward facing mounting surfaces  68  for floor mounting configurations. 
     Dispensing unit  10  and cutting unit  12  are preferably configured in a relatively fixed orientation and spacing with respect to one another such that, when chaff rovings  34  are being unspooled from the one or more canisters  16  of dispensing unit  10 , tensile stress fluctuations on the rovings  34  are minimized. During dispensing operations, each chaff roving  34  may be drawn by the cutting unit  12 , unspooling the roving  34  from its respective chaff bundle  32  stored in a canister  16   
     With continued reference to  FIGS. 1 and 5 , dispensing unit  2  operably engages cutting unit  12 . Support surface  14  may be provided with an elongated opening  70  extending along the length of and located below platen roller  72  and cutter roller  74 , such that chopped countermeasure  8  fall through the opening  70  and exit the dispensing system  2 . Inwardly extending guide walls  76  and  78  on the forward and aft sides of opening  70  guide the chopped material  8  out of the system. In certain implementations, the chopped material  8  may be guided toward at least one hatch  6  (see  FIG. 1 .) The system may also be configured, as necessary, with bobbins and/or spools (not shown) to additionally guide the rovings  34  to the rollers. In other implementations, such as wing-mounted configurations, an optional spoiler member  80  (see  FIG. 5 ) positioned below the support surface  14  and extending along the opening  70 , assists in dispensing the chopped material  8  into the airstream along the flight path of the aircraft. 
     A guide  82  may be positioned near the roving dispensing ends (first end caps  44 ) of canisters  16  and upstream of rollers  72  and  74 . The guide  82  may comprise an elongated, smooth, curved plate for guiding and slightly pressing the rovings  34  from the canisters  16 - to the nip of rollers  72  and  74 . When a chaff bundle  32  is inserted into canister  16 , the feed ends  36  of the rovings are pulled from the canister  16  through apertures  54  threaded into the nip of rollers  72  and  74 , so that when the rollers are rotated, the rovings  34  are automatically drawn between the rollers under guide  82  for cutting. 
     Cutting unit  12  may include a drive structure  84  (shown in block form) that includes a drive shaft, flywheel and rotors as are well known in the art. The drive shaft may be connected to the rotor of a drive clutch assembly, while the stator of the clutch assembly may be connected to a gear assembly for driving one, or both of the cutter roller  74  and the platen roller  72 , to rotate with respect to the other, perhaps both rotating in opposite directions. Drive structure  84  may include an electrical motor, with an electrical cable  86  extending to controller  28  and power supply  30  that command the operation of the drive structure  84 , and, thus, the dispensing system. Controller  28 , which may include a switching device, electrically connects electric power supply  30  to drive structure  84  and outputs signals to each of its components to activate and/or deactivate the operations thereof, and thus control the rotation of the cutter roller  74  and/or the platen roller  72 . In certain embodiments, the drive structure  84  may additionally provide rotational motive force to each support rod  48 . Drive structure  84  may synchronize, electrically or mechanically, the rotation of the rollers  72 ,  74  and the support rods  48 , in order to assist in rotating the rods. 
     Platen roller  72  may be formed from rubber or another suitable elastomer, while the cutter roller  74  may be formed of steel or another suitable material. Cutter roller  74  is configured with a plurality of cutter blades  88 , extending along the length of and spaced around the circumference of the roller for cutting the strands of roving  34  to a suitable length. The spacing of the blades  88  around the circumference of roller  74  will determine the length of the dipoles cut. A number of replacement cutter rollers  74  may be interchanged to enable the cutting of dipoles of varying lengths. The knife-edge blades  88  are mounted in precisely machined grooves spaced around the circumference of the cutter roller  74 , and the cutter roller may be constructed in a manner well-known in the art. Guide  82  may extend the length of the platen roller  72  for maintaining a slight pressure on the strands of roving drawn into the nip of rollers  72  and  74 . Sufficient pressure is maintained by the blades  88  against the surface of the platen roller  72  to ensure proper countermeasure cuts. 
     Although various specific embodiments and illustrative features have been described, it will be recognized that the invention is not thus limited, except as by the appended claims, and that variations, modifications and other embodiments are contemplated and are to be broadly construed.