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.
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'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.
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'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'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.
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.
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'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
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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.
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Support rod 48 extends between first end 44 and second end 46 along an axis 56 axially traversing the center of the cavity 52 defined by the ends 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 44. In certain embodiments, this may be achieved by the inclusion, in first end 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 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 46. Alternatively, second end 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 46 and canister wall 50 to permit second end 46 to rotate. In certain implementations, either or both ends 44, 46 may comprise end caps that are removable from wall 50. For example, an end cap at second end 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.
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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 bore, wherein rack plates 62 each have a corresponding set of bores 64, 64′, 64″. 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,
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
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A guide 82 may be positioned near the roving dispensing ends (first ends 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.
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.