Winged vehicle with variable-sweep cantilevered wing mounted on a translating wing-support body

A winged vehicle includes an elongated fuselage, and a wing mechanism affixed to the fuselage. The wing mechanism has a wing-support-body track affixed to and extending lengthwise along the fuselage, a translating wing-support body engaged to and translatable along the wing-support-body track, and exactly two deployable cantilevered wings. Each deployable cantilevered wing has a wing pivot mounted to the translating wing-support body so that the deployable cantilevered wing is pivotable about the translating wing-support body. The two deployable cantilevered wings are each pivotable between a stowed position and a deployed position. An actuation mechanism is operable to controllably move the translating wing-support body along the wing-support-body track and to controllably move the two deployable cantilevered wings between the stowed position and the deployed position.

This invention relates to a winged vehicle wherein the wings are initially stowed and then are deployed when the winged vehicle is launched and, more particularly, to the deployment mechanism.

BACKGROUND OF THE INVENTION

Until recently, most bombs were of the unguided, gravity type. The bomb was aimed by the motion of the aircraft on which it was carried and which flew approximately over the target. The bomb was released from a location on the flight path estimated to cause the bomb to fall onto its target. After the bomb was dropped there was no control over its motion. The result was that the aircraft was exposed to defensive measures over the target for an extended period of time in a flight path that was required to be straight and level, and the accuracy of the bombing was always somewhat problematic.

Recent developments improved upon this type of earlier munition in important ways. Wings were affixed to the bomb so that it could be dropped at a distance from the target of many miles and would glide to its target. The bomber aircraft consequently had far less exposure to defensive measures. The glide bomb was also provided with movable control surfaces and a guidance system, typically based upon cooperation with a laser designator, an inertial navigation system, or the global positioning system. The guidance capability greatly improved the accuracy of the bombing and reduced collateral damage.

The flight distance of a glide bomb depends upon several factors, one of which is the length of the wings. Long, slender wings result in long glide distances. However, long, slender wings take up a great deal of space in the bomb deployment racks on the launching aircraft. It has therefore become an established practice to fold the wings to a folded position along the fuselage of the glide bomb for storage, and then to pivot the wings to an open, deployed position when the bomb is dropped.

However, even this approach is not fully satisfactory in that it does not permit optimal-length and optimal-performance wings to be used with many types of bombs. There is accordingly a need for an improved approach to glide bombs and other types of winged weapons such as some types of powered missiles, which further improves their aerodynamic performance. The present invention fulfills this need, and further provides related advantages.

SUMMARY OF THE INVENTION

The present invention provides a winged vehicle in which the wings are initially folded in a stowed position when the winged vehicle is carried on its launcher aircraft, and then are opened to a deployed position when the winged vehicle is separated from the launcher aircraft. The wings are longer than is possible with a conventional pivoting-wing design, improving the flight performance of the winged vehicle.

In accordance with the invention, a winged vehicle includes an elongated fuselage, and a wing mechanism affixed to the fuselage. The wing mechanism has a wing-support-body track affixed to and extending lengthwise along the fuselage, a translating wing-support body engaged to and translatable along the wing-support-body track, and exactly two deployable cantilevered wings. Each deployable cantilevered wing has a wing pivot mounted to the translating wing-support body so that the deployable cantilevered wing is pivotable about the translating wing-support body. The two deployable cantilevered wings are each pivotable between a stowed position and a deployed position. An actuation mechanism is operable to controllably move the translating wing-support body along the wing-support-body track and to controllably move the two deployable cantilevered wings between the stowed position and the deployed position.

Significantly, in the present approach there are exactly two deployable cantilevered wings. That is, both (i.e., all) of the deployable cantilevered wings are mounted to the wing-support body in a cantilevered fashion. There are no struts or other external bracing (sometimes called “aft wings”, depending upon their surface area) that deploy along with the deployable primary wings, as in U.S. Pat. No. 5,899,410. Such struts add weight and drag without providing a corresponding benefit in added lift. Additionally, such struts typically do not have their pivot points on the wing-support body, so that their center of lift does not move in the same manner as does the center of lift of the deployable wings.

The actuation mechanism may be of any operable type and may include any operable type of drive. Examples of operable drives include an electromechanical actuator, a pneumatic actuator, a gas actuator, or a spring actuator. There may be one, two, or more individual actuators (also termed drives or drive motors). Typically, there is either one actuator whose operation controls both the linear movement of the wing-support body and, through gearing or other linkage, the pivoting movement of the wings; or two actuators, one driving the linear movement of the wing-support body and the other the pivoting movement of the wings. In one preferred approach using exactly one actuator, the deployable cantilevered wings pivot about their respective wing pivots in mechanical linkage with a movement of the translating wing-support body. This movement may be accomplished, for example, by a leadscrew drive that controllably moves the translating wing-support body, and a gear structure that pivots the deployable cantilevered wings responsive to the movement of the translating wing-support body. Thus, in one form, an actuation mechanism operable to controllably move the translating wing-support body along the wing-support-body track comprises a leadscrew operable between the fuselage and the translating wing-support body, an electromechanical drive motor that turns the leadscrew, and a pivot mechanism whose turning produces a pivoting movement of the deployable cantilevered wings about their respective wing pivots relative to the translating wing-support body.

In another embodiment, the movement of the wing-support body and the deployment of the wings may be separately driven, by two independently operating actuators. In this case, a first drive is stationary and drives the wing-support body, and a second drive is supported on the wing-support body and moves the wings between the stowed and deployed positions.

The winged vehicle may further include an attachment structure that attaches the winged vehicle to a launcher. The winged vehicle may also have a movable guidance surface and a warhead. The winged vehicle may be unpowered or it may have a propulsion system.

In a preferred design, the fuselage has a nose and a tail, and the first position of the wing-support body is closer to the nose than is the second position. That is, as the deployable cantilevered wings deploy, the wing-support body slides rearwardly along the wing-support-body track. When the deployable cantilevered wings are folded to their stowed position, they lie along or near to the fuselage. Because the wing-support body is in its forward-most first position, there is sufficient length along the fuselage for the deployable cantilevered wings to be long yet not extend beyond the tail of the fuselage and not be interfered with by other structure such as the movable guidance surfaces or antennas that may be present. However, it would not be satisfactory for the wing-support body to remain in this forward-most first position when the deployable wings were deployed to their open positions, as the center of aerodynamic lift would be so far forward of the center-of-gravity that the winged vehicle would not be readily flyable in a stable manner. The wing-support body and thence the pivot point of the deployable cantilevered wings is therefore translated rearwardly as the deployable wings deploy, to the second position where the center of gravity and the center of aerodynamic lift are satisfactorily positioned for flight. The result is that the winged vehicle has a greater range due to the longer deployable cantilevered wings, yet is still readily stowed in available weapons bays and on available launchers.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1–4depict a first embodiment of a winged vehicle20having an elongated fuselage22with a direction of elongation24, a nose26, and a tail28. Extending from the fuselage22at a location near the tail28are four optional, but preferably present, movable guidance surfaces30extending outwardly from the fuselage. The optional movable guidance surfaces30are moved by actuators (not visible in the drawings) inside the fuselage22responsive to commands from an optional controller32that senses the position of the winged vehicle20in relation to its target and guides the winged vehicle20toward its target by movements of movements of the guidance surfaces30. The controller32may optionally include other consistent features found in winged vehicles and known in the art, such as radar or infrared seekers, inertial or GPS guidance units, laser guidance units, transceivers, and communications uplinks and downlinks. A warhead (not visible in the drawings) typically occupies a major portion of the interior of the fuselage. The winged vehicle20ofFIGS. 1–4is a glide bomb, and has no internal propulsion system. On an upper side34of the fuselage22is an attachment structure36that detachably attaches the winged vehicle20to a launcher (not shown) such as an aircraft that carries the winged vehicle20prior to launch. In the illustrated embodiment, the attachment structure36is a pair of conventional attachment lugs that interface with the launcher, but other attachment structures may be used as well.

A wing mechanism38is affixed to the fuselage22, in this case to the upper side34of the fuselage22. Equivalently for the present purposes, the wing mechanism38may be affixed to the lower side of the fuselage or to structure within the fuselage. The wing mechanism38includes a wing-support-body track40affixed to and extending lengthwise along the fuselage22parallel to the direction of elongation24. A wing-support body42is engaged to and translatable along the wing-support-body track40in a sliding movement parallel to the direction of elongation24. A pair of (i.e., exactly two) deployable cantilevered wings44are pivotably affixed by respective pivots46to the wing-support body42. As used herein, “cantilever” and “cantilevered” refers to a form of wing construction in which no external bracing is used. That is, each cantilevered wing44is supported only from a position near its inboard end, and specifically from the pivots46. There is no external bracing (which may be variously called a strut or an aft wing or the like) as in the designs described and illustrated in U.S. Pat. No. 5,899,410. Such external bracing is necessary to the deployment mechanism in the '410 patent, but it adds weight and drag without providing a corresponding benefit in added lift. Additionally, pivoting external bracing typically does not have its pivot points on the wing-support body, so that the center of lift does not move in the same manner as it does for the deployable cantilevered wings. The use of the cantilevered-wing design of the present approach provides a significant weight and aerodynamic advantage over externally braced designs.

Each of the deployable cantilevered wings44is movable between (1) a stowed position illustrated inFIG. 1wherein the deployable cantilevered wings44lie relatively close to the fuselage22when the wing-support body42is in a first position48along the wing-support-body track40, and (2) a deployed position illustrated inFIG. 4wherein the deployable cantilevered wings44are deployed to extend relatively outwardly from the fuselage22when the wing-support body42is in a second position50along the wing-support-body track40. In the illustrated embodiment, the first position48is closer to the nose26than is the second position50, so that the wing-support body42moves rearwardly as the deployable cantilevered wings44deploy from the closed position to the open position. The deployable cantilevered wings44preferably move symmetrically relative to the fuselage22. The extent of movement between the first position48and the second position50is indicated by dimension52inFIG. 4.

In other embodiments, the deployable cantilevered wings44may extend straight outwardly from the fuselage or be forwardly swept in the open position, as distinct from the rearwardly swept deployable cantilevered wings shown inFIG. 4. In yet other embodiments, the wing-support body may move forwardly as the deployable cantilevered wings deploy from the closed to the open position. All of these embodiments are accomplished with changes to the direction and extent of movement of the wing-support body42.

An actuation mechanism54is operable to move the two deployable cantilevered wings44from the stowed position ofFIG. 1to the deployed position ofFIG. 4. The actuation mechanism54may be of any operable type.FIGS. 5–6illustrate one preferred form of the actuation mechanism54. In this actuation mechanism54, there is a single drive motor that drives the wing-support body42along the wing-support-body track40parallel to the direction of elongation24. The deployable cantilevered wings44pivot about their respective pivots46responsive to and in mechanical linkage with this movement of the wing-support body42, so that only a single drive motor is required to accomplish both the movement of the wing-support body42and the pivoting motion of the cantilevered wings44. This actuation mechanism54allows the cantilevered wings44to be controllably deployed by various amounts from a highly swept configuration to a widely extended, low-sweep configuration in which the cantilevered wings44each extend at or near 90 degrees to the fuselage22. The forward-aft position of the wing-support body42is appropriately adjusted for the entire range of sweep configurations so that the center of lift stays appropriately positioned relative to the center of gravity of the winged vehicle20.

More specifically in the design for the actuation mechanism54as shown inFIGS. 5–6, a leadscrew drive56includes a leadscrew58that engages a leadscrew follower60fixed to the wing-support body42, and a single electromechanical drive motor62that rotationally drives the leadscrew58. The leadscrew58and the drive motor62are both mounted within the fuselage22of the winged vehicle20. As the leadscrew58turns, the follower60causes the wing-support body42to move along the wing-support-body track40parallel to the direction of elongation24according to the direction of rotation of the leadscrew58. The deployable cantilevered wings44are mounted to the wing-support body42by the respective pivots46(but no struts), and travel along the direction of elongation24as the leadscrew turns58.

In the embodiment ofFIGS. 4–5, the deployable cantilevered wings44are pivoted between the folded and deployed positions by a gear structure64, although other operable deployment mechanisms may be used. In the illustrated embodiment, the gear structure pivots the deployable cantilevered wings44responsive to the movement of the wing-support body42, without the need for a separate drive motor in addition to the drive motor62. Each of the deployable cantilevered wings44has a set of wing teeth66along the periphery68of a base thereof. The wing teeth66of the two deployable cantilevered wings44engage each other, so that the pivoting of the two deployable cantilevered wings44occurs together in a coordinated fashion, to the same deployment angle (i.e., sweep angle) relative to the direction of elongation24. A spur gear70, which serves as a pivot gear, engages the wing teeth66of one of the two deployable cantilevered wings44, so that the turning of the spur gear70causes the engaged deployable cantilevered wing44to pivot on its pivot46. The engagement of the wing teeth66between that first-driven deployable cantilevered wing44and the second deployable cantilevered wing44causes that second deployable cantilevered wing to turn on its pivot46by an identical amount.

The spur gear70is mounted on a shaft72to turn with a pinion gear74. The shaft72is mounted with a bearing76to the wing-support body42and therefore moves with it. The pinion gear74engages a rack78that is stationary in the fuselage22and extends parallel to the axis direction of elongation24. As the wing-support body42moves when driven by the leadscrew drive56, the engagement between the pinion gear74and the rack78causes the shaft72and thence the spur gear70to turn. The turning of the spur gear70causes the deployable cantilevered wings44to pivot about their respective pivots46, so as to move toward the folded position or toward the deployed positions, depending upon the direction that the leadscrew58turns. The leadscrew58is not directly geared to the spur gear70. Instead, the turning of the leadscrew58indirectly causes the spur gear70(i.e., the pivot gear) to turn, deploying the cantilevered wings44.

Other operable types of drives for the actuation mechanism54may be used, such as a pneumatic actuator or a gas actuator having a cylinder linked to the wing-support body42, or a spring actuator. The actuator58may accomplish the movement of the deployable cantilevered wings44by operating upon any portion of the structure formed between the wing-support body42and the deployable cantilevered wings44.

As may be seen by an inspection ofFIG. 4, if the wing-support body42were fixed in the second position50, the ends of the deployable cantilevered wings44would contact the movable guidance surfaces30as the deployable cantilevered wings44folded from the closed toward the open position, or would extend past the tail28and possibly interfere with the structure of the launching aircraft or other weapons positioned behind the winged vehicle20. By positioning the wing-support body42in the first position48ofFIG. 1when the deployable cantilevered wings44are folded and stowed, the deployable cantilevered wings44may be made longer than would be otherwise possible and still not interfere with the movable guidance surfaces30or extend past the tail28in the stowed position, adding to the lift and range of the winged vehicle20. For this reason, the first position48is desirably located as close to the nose26as possible, consistent with the other requirements of the winged vehicle20. When the deployable cantilevered wings44deploy and the wing-support body42moves to the second position50ofFIG. 4, the center of the lifting force of the deployable cantilevered wings44(i.e., the center of lift) is properly positioned along the length of the winged vehicle20for the proper positioning of the aerodynamic forces and the center of gravity of the winged vehicle20.

The present drive system for opening the cantilevered wings44permits the two cantilevered wings to be coplanar upon opening, as depicted inFIG. 7, or to have a dihedral upon opening, as illustrated inFIG. 8. The coplanar-opening embodiment ofFIG. 7is achieved by providing the spur gear70in a rectangular form with the spur-gear teeth82parallel to each other. The spur-gear shaft72and the wing pivots46are parallel to each other. The dihedral-opening embodiment ofFIG. 8is achieved by providing the wing teeth66and/or the spur gear70in a beveled form, by angularly offsetting the spur-gear shaft72and the wing pivots46by the angle of the bevel and thence the angle A of the dihedral, and by driving the movement with a flexible shaft.

FIG. 9illustrates a second embodiment of the winged vehicle20, wherein elements common with the embodiments ofFIGS. 1–6are assigned the same reference numerals, and the prior discussion is incorporated. In the embodiment ofFIG. 9, there is additionally a propulsion system80. In this case, the propulsion system is in the form of a small solid rocket motor, but it may be a jet engine or other operable propulsion system. The winged vehicle20in this case may be a guided missile or a guided bomb that has a propulsive assist. A different drive motor configuration is used, with the drive motor being a pneumatic actuation mechanism with a cylinder and extendable drive piston that engages the wing-support body42, and which as illustrated is positioned forward of the wing-support body42. The nose26is also of a more aerodynamic shape than the generally hemispherical nose ofFIGS. 1–4. These variations may be used singly or together, and in any operably combination with the features of theFIGS. 1–8embodiments.

In the embodiments ofFIGS. 1–6and9, a single drive motor62is used both to drive the wing-support body42along the tracks40, and also to open and close the wings44via the rack-and-pinion mechanism. This approach uses only a single drive motor to reduce weight, but it also limits the relation of the sweep of the wings44(i.e., how far the wings have opened from the fully stowed position toward the fully deployed position) and the forward-aft position of the wing-support body42to a preselected relation. If it is desired to have the ability to set the wing sweep independently of the forward-aft position of the wing-support body42, the movement of these two components may be decoupled so that they are separately movable.

FIG. 10illustrates another embodiment of the wing mechanism38that achieves this decoupled movement. InFIG. 10, elements common with the embodiments ofFIGS. 1–9are assigned the same reference numerals, and the prior discussion is incorporated. In the approach ofFIG. 10, the actuation mechanism54includes two drives, a first drive that moves the wing-support body along the wing-support-body track, and a second drive that controllably moves the two deployable cantilevered wings between the stowed position and the deployed position. In the illustrated embodiment, a first drive motor90drives the wing-support body42in the fore-aft direction parallel to the direction of elongation24, by driving a first leadscrew92engaging a first leadscrew follower94on the wing-support body42. A second drive motor96is supported on and rides on the wing-support body42, along with the wings44affixed to the wing-support body42by the pivots46. The second drive motor96drives a second leadscrew98that engages a second leadscrew follower100. (Other types of drives may be used as well, such as pneumatic drives, gas drives, or spring drives. The two drives may be of the same or different types.) A pair of bell crank arms102extend from the second leadscrew follower100to a respective off-pivot attachment104on each of the wings44. As the second leadscrew follower100moves parallel to the direction of elongation24, it opens or closes the two wings44in a coordinated fashion. The two drive motors90are operated independently of each other, so that the wings44may be opened independently of the movement of the center of lift parallel to the direction of elongation24by movement of the wing-support body42. The controller32(FIG. 3) controls the two drive motors90and96independently of each other. This independent operation allows more control of the aerodynamics of the winged vehicle20than the single-motor approach ofFIGS. 1–6and9, at a cost of greater weight. These approach ofFIG. 10may be used with other compatible features of theFIGS. 1–9embodiments. In an alternative form, the structure ofFIG. 10may be used with a single drive motor, and the wing support body42and bell crank arms102linked together by a gear or other linkage. The relative rate of movement of the wing support body42and the opening of the wings44is then established by the gear ratio of the linkage gear.