Patent Application
20120074163
Not Applicable
Not Applicable
1. Field of the Invention
The present invention relates generally to mission configurable infrared countermeasures for aircraft, and more particularly to a deployment device which accommodates infrared decoy foils within multiple canisters so as to allow for the control dispensing and dispersal of the foils. The infrared foils are typically a Special Material (SM) which, when brought into contact with air, become warm and radiate infrared energy.
2. Description of the Related Art
As is well known in the prior art, military aircraft are typically provided with countermeasures which are used to draw various types of guided weapons away from the aircraft. One common prior art countermeasure is a flare which is adapted to attract infrared or heat seeking guided missiles away from the deploying aircraft. In this respect, the flare is designed to present a larger thermal target than the aircraft from which it is deployed, thus attracting the weapon away from the aircraft.
With continuing advances in weapons technology, flares have become less effective as countermeasures due to anti-aircraft weaponry having become more sophisticated and provided with enhanced capabilities to discriminate between flares and the deploying aircraft. In this respect, modern heat seeking missiles are typically provided with both a spectral discriminator which is adapted to sense the peak intensity wavelength of the infrared signature of the aircraft and a kinetic discriminator which is adapted to sense the speed and trajectory at Which the infrared signature is traveling. When a conventional flare is deployed from the aircraft, the infrared signature produced thereby is typically more intense in the near visible wavelength than that produced by the engines of the aircraft. In addition, the velocity and trajectory of the flare is significantly different than that of the deploying aircraft since the flare, once deployed, slows rapidly and falls toward the ground. The spectral discriminator of the guided missile is adapted to distinguish between the infrared signature produced by the flare and that produced by the engines of the aircraft. Additionally, the kinetic discriminator of the guided missile is adapted to distinguish between the velocity and trajectory of the aircraft and that of the flare, even if the spectral discriminator does not distinguish the infrared signatures produced thereby. As such, the combined functionality of the spectral and kinetic discriminators of the guided missile typically succeeds in causing the guided missile to disregard the deployed flare, and continue to target the aircraft.
In view of the above-described shortcomings of conventional flares, there has been developed in the prior art countermeasure systems which are adapted to create an infrared signature which is similar in magnitude or intensity to that produced by the aircraft engines, appears to travel at a velocity and trajectory commensurate to that of the aircraft, and can provide continuous protection while the aircraft is over threat territory. Examples of these prior art systems are shown and described in Applicant's U.S. Pat. No. 5,915,694 entitled DECOY UTILIZING INFRARED SPECIAL MATERIAL and U.S. Pat. No. 6,499,407 entitled PACKAGING METHOD FOR INFRARED SPECIAL MATERIAL, the disclosures of which are incorporated herein by reference.
These and other prior art references generally teach the dispensation of SM foils from an aircraft by stacking the SM foils in a canister and ejecting them either all at once using an explosive charge, or in small packets or continuously from a canister using a drive screw or similar device. The principle disadvantage of the all at once dispensation approach is that it provides only momentary protection in one intense cloud which does not follow the aircraft. This particular problem has been addressed by devices that dispense the SM foils approximately continuously such that the infrared cloud produced thereby appears to match the aircraft kinematics. Such continuous dispensation has been accomplished successfully in the prior art for relatively short stacks of SM foils through the use of a piston driven by a lead screw, and also by packaging the SM foils into small packets which engage a drive belt that drives them out of a corresponding canister.
However, in order to provide protection for an extended period of time, it is desirable to package the SM foils into canisters with more volume. While this can be accomplished by engaging individual packets of SM foils to a drive belt as described above, the method is more mechanically complex, less volume efficient and allows less flexibility in how the SM foils are dispensed than does a canister with a piston/lead screw. Unfortunately, the use of a piston/lead screw canister to facilitate the deployment of long columns of SM foils itself gives rise to certain problems. Existing piston/lead screw canisters typically comprise a hollow tube with a piston at one end, and spring fingers at the other. The SM foil stack is located between the piston and spring fingers. The purpose of the spring fingers is to retain the SM foils until such time as they are forced out of the canister by the piston. The stack of SM foils has a great deal of compliance. Since none of the SM foils are perfectly flat, the column acts as a spring. As the piston drives the SM foils out, the SM foil stack compresses against the spring fingers until they finally let go, at which time a large slug of SM foils is dispensed. This effect is minimal for short stacks of SM foils, but prevents controlled and uniform dispensing of long stacks of SM foils. The present invention, as will be described in more detail below, overcomes these and other deficiencies of the prior art.
In accordance with the present invention, there is provided a deployment device that is operative to deploy Special Material (SM) to protect a vehicle when an enemy infrared (IR) threat is present. Commonly used on aircraft, SM protects the aircraft by moving its IR signature away from the host craft, thus protecting the aircraft (and crew) from missile attack. The deployment device constructed in accordance with the present invention comprises at least one, and preferably a pair of canisters which are each filled or loaded with SM, then factory sealed to prevent oxidation or contamination. Each canister can be stored for prolonged periods, and then installed into the deployment device when needed. As indicated above, one or more canisters can be included in the deployment device constructed in accordance with the present invention, with two canisters being provided in one embodiment thereof.
Each of the canisters included in the deployment device includes an input shaft which, when rotated, is operative to transmit the rotary motion to each of four threaded rods. The rods have two primary functions, which are to advance a piston within the canister toward the open end thereof, and to turn rotary metering devices (e.g., augers) which are located at the open end of the canister and cooperatively engaged to respective ones of the rods. The advancing piston maintains consistent compression in the SM stack within the canister. Additionally, the rotary metering devices which are located in respective ones of the four corners of the canister at the aft end thereof control and thus meter how the SM is dispensed into the airstream behind the aircraft. In this regard, the rotary metering devices have external features that interleave with the stack of SM. As the metering devices turn, the interleaving features continuously release and engage the SM stack, thus controlling the distinct amount of SM released. If the canister's input is turned rapidly, more material will be dispensed than if the input is turned slowly. When stationary, the metering devices positively retain the SM stack within the canister.
The present invention is best understood by reference to the following detailed description when read in conjunction with the accompanying drawings.
These and other features of the present invention, will become more apparent upon reference to the drawings wherein:
Common reference numerals are used throughout the drawings and detailed description to indicate like elements.
Referring now to the drawings wherein the showings are for purposes of illustrating one exemplary embodiment of the present invention only, and not for purposes of limiting the same,
Referring now to
In addition to the housing 14 each canister 12 of the deployment device 10 comprises a plurality of (e.g., four) elongate drive members, and more particularly threaded rods 24 which extend within respective ones of the channels 22. The length of each of the rods 24 exceeds that of the housing 14 such that opposed end portions of each of the rods 24 normally protrude from respective ones of the forward and aft end 16,18 of the housing 14. As best seen in
As further seen in
Within the canister 12, the drive gears 28 and transmission gears 32a-32d are covered or shielded by a quadrangular (e.g., square) end plate 24 which is mounted to the base plate 26. The exterior surface features or contours of the end plate 34 mirror those of the base plate 26 such that the peripheral surface of the end plate 34 is substantially flush or continuous with the peripheral surface of the base plate 26 and hence the outer surface of the housing 14 when the end plate 34 is mounted to the base plate 26, as is shown in
Referring now to
As further seen in
As also seen in
Mounted to the support frame 36 of each canister 12 is a support plate 44 which, like the support frame 36, defines a circularly configured central opening which is positioned along the axis A. In this regard, when the support plate 44 is attached to the support frame 36, the central opening of the support plate 44, the central opening of the support frame 36, and the interior chamber 20, which are each of substantially equal diameter, are coaxially aligned with each other. In addition to the central opening, the support plate 46 also includes four apertures disposed in within respective ones of the four corner regions defined thereby, these apertures also rotatably accommodating the end portions of respective ones of the rods 24. As seen in
As seen in
Referring now to
As is apparent from the foregoing, the axial movement of the piston 50 of each canister 12 is dependent upon the concurrent rotation of the rods 24 thereof, which is itself dependent upon a rotary input force being applied to the rod 24 defining the drive input and including the slot 30. In the deployment device 10, a rotary input force is exerted upon those rods 24 of the two canisters 12 defining the drive inputs by a drive unit 56 which is attached to the end caps 48 of the side-by-side canisters 12. As seen in
In the deployment device 10 constructed in accordance with the present invention, each of the canisters 12 are advanced through a mainframe 68, with that end or face of each support frame 36 disposed furthest from the end cap 48 being abutted against one side or face of the mainframe 68, as best shown in
In the deployement device 10, each end cap 48 is maintained in its closed position by the cooperative engagement of the latch members 43 of the corresponding canister 12 to the springs 51 of the end cap 48. More particularly, when compressive pressure is applied to the end cap 48 at a level sufficient to overcome the biasing force exerted thereon by the corresponding biasing spring 71, the end cap 48 is pivoted from its open position (shown in
As indicated above, the concurrent rotation of the rods 24 facilitates the movement of the piston 50 within the interior chamber 20 of the corresponding canister 12 along the axis A. In the deployment device 10, the initial rotation of each of the rods 24 (and hence each of the latch members 43) at an initial interval of approximately 120° facilitates the removal of the resilient end portions of each spring 51 from within the notches 45 of the corresponding pair of latch members 43. As will be recognized by those of ordinary skill in the art, the disengagement of the springs 51 of the end cap 48 from the latch members 43 of the corresponding canister 12 allows the end cap 48 to “spring” from its closed position to its open position as a result of the biasing force exerted thereon by the corresponding biasing spring 71 and intervening hinge member 70. As will further be recognized by those of ordinary skill in the art, once the end cap 48 actuates to its open position, the return thereof to the closed position is effectuated by pushing the end cap 48 as needed to overcome the biasing force exerted by the biasing spring 71 and facilitate the reinsertion of the latch members 43 into respective ones of the openings 49, the latch members 43 thereafter being rotated as needed to facilitate the reinsertion of the resilient end portions of the springs 51 of the end cap 48 into respective ones of the notches 45 of the latch members 43.
As best seen in
The completely assembled deployment device 10 as shown in
Having thus described the structural attributes of the deployment device 10, one particular mode of operation will now be discussed. Each canister 12 of the deployment device 10 is prepared by loading a stack of SM foils 21 into the interior chamber 20 thereof. As explained above, each canister 12, after being filled or loaded with the SM foils 21, is factory sealed to prevent oxidation or contamination. Individual canisters 12 may be stored for prolonged periods, then assembled into the deployment device 10 when needed. Each of the SM foils 21 has a generally round or circular shape, and is stacked into the interior chamber 20 of each canister 12 aft of the piston 50.
When the deployment device 10, including the side-by-side canisters 12, is operatively positioned on an aircraft, the use of the deployment device 10 is initiated by activating the drive unit 56 in a manner facilitating the pivotal movement of one or both of the end caps 48 from the closed position to the open position. As indicated above, each end cap 48 is moved from the closed position to the open position by initiating the rotation of the rods 24 of the corresponding canister 12 in an amount sufficient to facilitate the disengagement or release of the springs 51 of the end cap 48 from with the notches 45 of the latch members 43 attached to the rods 24. Such release or disengagement allows the biasing force exerted upon the end cap 48 by the corresponding biasing spring 71 via the intervening hinge member 70 to facilitate the pivotal movement of the end cap 48 to its open position. The rotation of the rods 24 of each canister 12 is facilitated by the application of a rotary input force to that rod 24 of the canister 12 which defines the drive input thereof. As indicated above, such input force is supplied by the drive unit 56 which is mechanically coupled to those rods 24 of the canisters 12 which define the drive inputs.
When the rod 24 of the canister 12 defining the drive input is rotated, the rotary motion is transmitted to the remaining three rods 24 via the transmission gears 32a-32d in the above-described manner. As also explained above, the concurrent rotation of all four threaded rods 24 at an initial increment of approximately 120° facilitates the movement of the end cap 48 of the canister 12 from its closed position to its open position. The continued rotation of all four threaded rods 24 after the opening of the end cap 48 facilitates the advancement of the piston 50 from its original position adjacent the forward end 16 of the housing 16 toward the aft end 18 thereof. The rotation of the rods 24 also facilitates the concurrent rotation of the rotary metering devices 38 cooperatively engaged thereto. The advancing piston 50 maintains constant compression in the stack of SM foils 21 previously loaded into the interior chamber 20 of the canister 12. Advantageously, the rotary metering devices 38 control and thus meter how the SM foils 21 are dispensed into the air stream behind the aircraft. More particularly, the blades 42 of the rotary metering devices 38 which protrude into the central opening of the support frame 36 of the canister 12 as described above interleave with the stack of SM foils 21. As a result, as the rotary metering devices 38 rotate, the interleaving features defined by the blades 42 thereof continuously release and engage the stack of SM foils 21, and effectively control the distinct amount of SM foils 21 released from the canister 12. If the rod 24 defining the drive input of the canister 12 is turned rapidly, more of the SM foils 21 will be dispensed then if such rod 24 is turned slowly. When the rods 24 are stationary, the rotary metering devices 38 function to positively retain the stack of SM foils 21. Thus, the rotary metering devices 38 effectively function as displacement control devices, with every turn of the rod 24 defining the drive input facilitating the release of a discreet amount of the SM foils 21 from the canister 12.
As indicated above, a diametrically opposed pair of the rotary metering devices 38 rotate in a first (clockwise) direction, with the rotary metering devices 38 of the remaining diametrically opposed pair rotating in a second (counter-clockwise) direction. Importantly, these differing rotational directions effectively prevent the rotary metering devices 38 from actually rotating the stack of SM foils 21 as they rotate, which could otherwise occur if all four rotary metering devices 38 rotate in the same direction. As shown in
Referring now to
As previously explained, when the rotary metering devices 38 are included in the deployment device 10, a first diametrically opposed pair of such rotary metering devices 38 are preferably rotated in a different rotational direction than the remaining diametrically opposed so as to prevent the rotary metering devices 38 from actually rotating the stack of SM foils 21. However, if the alternately configured rotary metering devices 38a are integrated into the deployment device 10, the need to rotate one diametrically opposed pair of the rotary metering devices 38a in a first direction while rotating the remaining diametrically opposed pair in a second, opposite direction to prevent rotation of the stack of SM foils 21 is effectively eliminated due to the above-described structural attributes of the rotary metering devices 38a. More particularly, such differing rotational directions are not needed since the blade members 42a, 43a of each rotary metering device 38a have no helix angle. Therefore, even if the SM foils 21 of the corresponding stack do rotate, there is no effect on metering. Those of ordinary skill in the art will recognize that further alternate embodiments of the rotary metering devices are contemplated to be within the spirit and scope of the present invention.
The initial loading of the stackable SM foils 21 into the interior chamber 20 of the canister 12 is made easier by the absence of any jack screw extending directly along the axis A of the interior chamber 20. Additionally, the dispensation of the SM 21 foils from the canister 12 is assisted by the guide tabs 46 of the corresponding support plate 44.
This disclosure provides exemplary embodiments of the present invention. The scope of the present invention is not limited by these exemplary embodiments. Numerous variations, whether explicitly provided for by the specification or implied by the specification, such as variations in structure, dimension, type of material and manufacturing process, may be implemented by one skilled in the art in view of this disclosure.
