Space saving wing stowage

A guided projectile includes a body and a deployable wing in which the deployable wing is coupled to and enclosed by the body. A linear distance from the leading edge to the trailing edge of the wing defines a chord line that, in the stowed position, forms an angle with a plane containing the chord line and extending parallel to a longitudinal dimension of the wing in a deployed position.

BACKGROUND

The present invention relates generally to deployable airfoils and, more specifically, to airfoils deployed from a guided munition mid-trajectory.

Conventional mortar systems include an explosive projectile fired from a smooth-bored tube along a ballistic trajectory. The range of the projectile is primarily determined by the firing angle and the magnitude of the propellant used to propel the projectile from the tube and secondarily determined by wind conditions, firing and target elevations, among other environmental conditions. Increasing the maximum effective range of the mortar system involves increasing the propellant to impart a greater initial velocity to the projectile exiting the tube. However, because of a need for mortar systems to be portable by one or more persons, increasing the propellant undesirably increases the weight of the mortar system. Increasing the propellant also imparts larger forces on the projectile that must be accounted for with stronger materials, which generally increase cost, or increased material sections, further increasing the weight of the mortar system. Furthermore, conventional mortar systems fire unguided projectiles with discrete propellant charges that combine with the initial firing angle to target a point of impact. Accordingly, delivering a projectile to a desired point of impact often involves firing multiple projectiles in which operators apply minor corrections to the initial firing angle between successively-fired projectiles.

Recent attempts to improve the range and accuracy of conventional mortar systems have led to the introduction of guided projectiles, which are equipped with at least one deployable flow control aid. For instance, some projectiles are equipped with two or more canards located forward of the projectile center of gravity and two or more tail fins or stabilizers at an aft end of the projectile. Various configurations of optical sensors, gps antennas, cameras, and/or accelerometers can be used to control the orientation of the canards to guide the projectile to the point of impact while the tail fins stabilize the projectile along the trajectory. Other guided projectiles deploy wings that extend radially from the projectile near the projectile center of gravity to extend the range of the projectile. For launching, these flow control aids can be stowed against an exterior surface of the projectile or, in some instances, are stowed within a casing of the projectile.

For instance, some guided projectiles stow each wing within the projectile body by rotating each wing about a pivot. However, because each wing rotates along a plane parallel to a meridional plane of the guided projectile (e.g. a horizontal plane), the wings extend into a volume used for the payload. Guided projectiles utilizing this type of stowed wing must reduce the payload volume to provide clearance for the wings in the stowed position or increase the overall size of the projectile to compensate of the lost payload volume. Reducing the payload volume decreases the explosive power of the guided projectile while the increased weight of the larger projectile reduces projectile range and portability. However, because munition manufacturers continue to increase the range and power of guided projectiles, a need exists for connecting flow guides to a projectile such that the stowed flow guide does not inordinately interfere with the payload volume or, in other words, minimizes interference with the payload volume.

SUMMARY

In one embodiment, a guided projectile includes a body and a deployable wing coupled to and enclosed by the body. The deployable wing includes a chord line defined by a linear distance from a leading edge to a trailing edge of the wing. In a stowed position, the chord line forms an angle with a plane containing the chord line and extending parallel to a longitudinal dimension of the wing in the deployed position. In a further embodiment, a pivot couples the deployable wing to the body in which a rotational axis of the pivot is inclined laterally outward from the body and longitudinally forward towards a nose of the projectile.

In another embodiment, a projectile includes a nose, a body, and a tail boom opposite the nose along a longitudinal axis of the body. The projectile further includes a plurality of stabilizers extending from a mount on the tail boom and a deployable wing coupled to the body at a pivot. Rotation about the pivot moves the deployable wing from a stowed position to a deployed position. In the stowed or deployed positions, the linear distance from a leading edge to a trailing edge of the deployable wing defines a chord line. In the deployed position, a reference plane is defined by the chord line and a longitudinal dimension of the wing. In the stowed position, the chord line of the deployable wing forms an acute angle with the reference plane. In a further embodiment, the projectile further includes a spherical bearing and a plurality of followers affixed to the body of the projectile, each follower received by a groove formed in the lug.

DETAILED DESCRIPTION

FIG.1is an isometric view of guided projectile10extending along longitudinal axis12, which is located along a geometric center of projectile10. For the purposes of explanation, the following disclosure refers to projectile coordinate system13having mutually orthogonal axes. The X-axis of projectile coordinate system13is collinear with longitudinal axis12. A meridional plane of projectile10is any plane containing longitudinal axis12and, therefore, the X-axis of projectile coordinate system13. The X-Y plane defines a vertical meridional plane of projectile10, and the X-Z plane defines a horizontal meridional plane. The terms “vertical” and “horizontal” are used to refer to a particular meridional plane of projectile10and are not intended to fix each plane in space globally, but instead, the vertical meridional plane is nominally oriented along a direction of lift imposed on the projectile while the horizontal meridional plane refers to a meridional plane perpendicular to the vertical meridional plane. Thus, the vertical and horizontal meridional planes, or any other meridional plane, are meant to be local to projectile10, moving and rotating in fixed relation with respect to projectile10.

Furthermore, “longitudinal”, “longitudinally”, and the like refer to a lengthwise dimension of a component. As used in reference to projectile10, the longitudinal dimension is aligned with the X-axis of projectile coordinate system13. The “lateral” dimension of a component extends away from or towards longitudinal axis12and includes movements or dimensions with a Z-component within projectile coordinate system13. When used in reference to projectile10, “radial”, “radially”, and the like refer to movements or dimensions extending radially from longitudinal axis12and, thus, have a Y-component, a Z-component, or both a Y-component and a Z-component within projectile coordinate system13.

Projectile10includes forward section14, body section16, and aft section18centrally disposed along longitudinal axis12. Generally, forward section14forms a leading surface of projectile10and contains components used to acquire targets and control projectile10to a point of impact. Body section16contains the projectile payload and, as will be discussed further below, may contain deployable flow guides. Aft section18stabilizes projectile10as it travels along a trajectory and may also contain a propellant charge used to propel projectile10from a launching platform. Projectile10has a center of gravity that is generally located at or proximate to longitudinal axis12.

Forward section14includes nose20, which may have a rounded, conical, or other contoured shape that transitions from leading edge point22to a cross sectional shape of body24. Body24is shown as cylindrical inFIG.1, although ovular, oblong, or other cross-sectional shapes are possible for body24. Within nose20, a fuse, a trigger, a timer, a camera, a global positioning antenna, a laser, a controller, and other sensors and devices can be installed to provide data to projectile10in order to pilot projectile10to a desired point of impact and detonate a payload contained within body section16using known methods.

Aft section18includes a cylindrical tail boom26and aft body27that tapers from the cross-section of body24and extends to tail fin mount28. Located at a downstream-most portion of aft section18, pivots30couple retractable tail fins or stabilizers32to tail fin mount28, allowing the longitudinal direction of each tail fin32to be parallel with longitudinal axis12in a retracted position and extending radially from longitudinal axis12in a deployed position. Aft section18may further include an obturator or gas seal (not shown) seated within groove34, which limits or prevents gases resulting from the propellant charge from bypassing projectile10when fired from a launching tube (not shown).

Disposed intermediate of forward section14and aft section18, body section16may include one or more deployable flow guides such as starboard canard36R and port canard36L (collectively canards36) as well as starboard wing38R and port wing38L (collectively wings38). In some embodiments, flow guides such as canards36and wings38may be deployed from within body24and through slots40and42, respectively.

Typically, canards36are disposed forward of the center of gravity of projectile10and aft of forward section14. Extending from a meridional plane of projectile10, canards36are capable of pivoting about respective longitudinal axes of each canard36to modify a trajectory of projectile10.

In the deployed position, wings38extend laterally outward from a proximal end coupled to body24to a distal end or cantilevered wing tip. The proximal end of each wing38can be aligned with or in close proximity to the center of gravity of the projectile. In this sense, wings38are in close proximity of the projectile center of gravity when the position of wings38relative to the center of gravity, canards36, and other flow guides, if included, prevents unintended rolling, pitching, or yawing of projectile10along its trajectory.

Like canards36, wings38can extend radially from body24along a meridional plane of projectile10. Alternatively, wings38can extend laterally from body24along a plane that is offset from the horizontal meridional plane of projectile10in the deployed position. For instance, wings38can be high-mounted or low-mounted. In a high-mounted configuration, wings38are offset from the horizontal meridional plane such that the projectile center of gravity is below deployed wings38. Wings38with a low-mounted configuration are offset from the horizontal meridional plane such that the projectile center of gravity is above deployed wings38.

As shown inFIG.1, wings38are high-mounted. Accordingly, wings38are offset from the horizontal meridional plane such that the center of gravity of projectile10is radially inward from wings38or towards longitudinal axis12. Furthermore, canards36, wings38, or both can be swept forward toward nose section14or swept backward toward tail section18to achieve the desired aerodynamic performance.

Wings38are aerodynamically shaped, forming an airfoil-shaped cross-section normal to the longitudinal dimension of each wing38. An airfoil-shaped wing includes curved upper and lower surfaces that extend from a leading edge to a trailing edge. The contours of the upper and lower surfaces provide lift in the direction of the upper surface as is known in the art. Additionally, wings38can have a cambered airfoil profile measured as the difference between leading edge and trailing edge metal angles or a neutral airfoil profile in which the leading edge metal angle equals the trailing edge metal angle. Moreover, wings38can be coupled to projectile10such that a chord line extending linearly from the leading edge to the trailing edge of the airfoil forms an angle of attack with a freestream direction of airflow in the deployed position. Alternatively, wings19can extend parallel to the horizontal meridional plane of projectile10.

In the stowed position, wings38are enclosed within body24such that chord line C of each wing38forms chord angle CA (seeFIG.2) with respective planes containing the chord line and extending parallel to a longitudinal dimension of respective wings38in the deployed position. That is to say, in the deployed position, a plane can be defined that contains the chord line of wing38R and extends parallel to a longitudinal direction of wing38R. In some embodiments, the plane can be defined as extending along the longitudinal dimension of wing38R in the deployed position and parallel to the horizontal meridional plane of projectile10. In still other embodiments, the plane can be defined as any plane parallel to the horizontal meridional plane. However defined, in the stowed position, the chord line of wing38R forms chord angle CA with the plane defined by wing38in the deployed position. If wings38are twisted such that chord lines of successive sections taken normal to the longitudinal dimension are not coplanar, the chord line at a particular section, for example the wing tip or the lug-end of the wing, can be used to define chord angle CA in the stowed position. In the deployed position, each wing38rotates about its proximal end and through slots42to the deployed position shown inFIG.1.

While projectile10, as depicted inFIG.1, is suitable for a portable mortar system, the general applicability of the present invention will be apparent to those skilled in the art. For instance, deployable wings38can be stowed within a missile, rocket body, or other vehicle.

FIG.2depicts a partial cross-section of projectile10taken along plane A-A normal to longitudinal axis12and positioned between canards36and wings38. Starboard wing38R and port wing38L are stowed inFIG.2. Longitudinal dimensions of starboard wing38R and port wing38L extend parallel to longitudinal axis12of projectile10. Chord lines C of each wing form angles CA with respective planes containing chord line C and extending parallel to a longitudinal direction of respective wings in the deployed position. For embodiments having wings38orientated horizontally in the deployed position, each wing38also forms chord angle CA with the horizontal meridional plane of projectile10. As a result of chord angle CA, starboard wing38R and port wing38L closely conform to an interior surface of body24and permit payload area48to be larger than payload area50, which is available when stowing wings horizontally (i.e., chord angle CA equal to 0 degrees) or when stowing both wings along a single plane.

FIGS.3A,3B,3C, and3Ddepict the deployment sequence of starboard wing38R as viewed from cross-sections of projectile10taken along plane A-A.FIG.3Adepicts starboard wing38R in a stowed position, andFIG.3Ddepicts starboard wing38R in a deployed position.FIGS.3B and3Cdepict starboard wing38R in partially deployed positions. Although the following discussion describes deployment of starboard wing38R and associated components, port wing38L includes the same components and functions in the same manner as starboard wing38R except that port wing38L is configured as the mirror image of starboard wing38R about the vertical meridional plane (i.e., plane X-Y of projectile coordinate system13).

The degree of wing deployment is described by the deployment angle measured between longitudinal axis12and a projection of leading edge44of each wing38onto the horizontal meridional plane. Accordingly, a wing with a leading edge parallel to longitudinal axis12has a deployment angle equal to 0 degrees, and a wing in the deployed position has a positive deployment angle. Wings38can have a maximum deployment angle less than 90 degrees for forward-swept wings or can have a maximum deployment angle greater than 90 degrees for backward-swept wings. Alternatively, leading edges44of wings38can extend perpendicularly with respect to longitudinal axis12, having a deployment angle equal to 90 degrees. In the embodiment depicted byFIG.3A, leading edge44of starboard wing38R forms a deployment angle approximately equal to 0 degrees. Furthermore, the deployment angle of starboard wing38R is approximately 4 degrees inFIG.3B, approximately 15 degrees inFIG.3C, and approximately 90 degrees inFIG.2D.

FIG.3Adepicts chord line C of starboard wing38R in further detail. As noted above, chord line C is the linear distance extending from leading edge44to trailing edge46of each wing38. In the stowed position, the chord angle is measured between chord line C and a plane containing chord line C and extending parallel to a longitudinal dimension of starboard wing38R in the deployed position. In the depicted case, chord line C also forms chord angle CA with the horizontal meridional plane. As depicted inFIG.3A, chord angle CA is acute, ranging between 0 degrees (i.e., parallel to the horizontal meridional plane of projectile10) and 90 degrees (i.e., perpendicular to the horizontal meridional plane of projectile10). The value of chord angle CA for a wing in the stowed position depends on a profile of an interior surface of body24and the length of chord line C. For example, a wider range of chord angles CA may be available for wings with relatively short chord lengths C since shorter chord lengths C can more easily fit within a given projectile body relative to larger chord lengths C.

To maximize payload volume48, wings38closely conform to the interior surface of body24. In other words, chord line C of wings38are angled to approximate a profile of the interior surface of body24such that leading edge44and trailing edge46of starboard wing38R are immediately adjacent to the interior surface of body24.

When wings38have a nonzero chord angle CA in the stowed position, cross-sectional area48is available for payload. By comparison, if wings38were deployed along a horizontal plane, cross-sectional area50, represented by dashed lines, would be available for payload since chord line C would extend parallel to the horizontal meridional plane. The payload volume, therefore, is defined by cross-sectional area48or cross-sectional area50projected along a length of body24. From this comparison, it is evident that additional cross-sectional area is available for payload when wings38are stowed with a nonzero chord angle CA.

Moreover, the shape of cross-sectional area48more-closely approximates a circular cross-section than cross-section50, which permits cross-sectional area48to detonate more efficiently than cross-sectional area50. Specifically, cross-section48includes circular arc48ajoined by linear side48bthat extends parallel to a side of keep-out region52required to store starboard wing38R within body24. While only one quadrant of cross-section48is depicted byFIG.3A, cross-section48is symmetrical about vertical and horizontal meridional planes of projectile10. Thus, cross-section48includes opposing circular arcs intersecting the horizontal meridional plane joined by opposing peaks formed by linear edges extending from opposing circular arcs and joined at an apex at the vertical meridional plane.

FIGS.3B and3Cdepict starboard wing38R as it transitions from the stowed position depicted byFIG.3Ato the deployed position depicted byFIG.3D. In the deployed position, starboard wing38R extends parallel to the horizontal meridional plane. To facilitate the transition from the stowed position to the deployed position, each wing includes lug54that couples each wing38to respective mounts56, which extend from the interior surface of body24. Together, lug54and mount56form pivot58coupling a proximal end of starboard wing38R to body24.

In the following description, several pivot embodiments are described that can be used to permit wings38to move from a stowed position to a deployed position. Some of the embodiments are described with respect to starboard wing38R while others are described with respect to port wing38L. Whether described with respect to starboard wing38R or port wing38L, any of the following embodiments can be applied to the other of the starboard and port wings38. In doing so, certain features and or coordinate systems may be mirrored about a vertical meridional plane of projectile10(i.e., the X-Y plane of coordinate system13) as will be apparent from the description.

FIGS.4A and4Bare cross-sectional views taken through starboard wing38R, lug54, and mount56depicting additional features of pivot58. The cross-sectional plane ofFIG.4Ais parallel to plane A-A (seeFIG.1), and the cross-sectional plane ofFIG.4Bis perpendicular to plane A-A and extends along longitudinal axis12. As shown byFIGS.4A and4B, lug54and mount56have opposing parallel surfaces54A and56A, respectively, which are normal to pivot axis P and thus perpendicular to lateral projection PW and longitudinal projection PL of pivot axis P. As a result, lateral projection PW of pivot axis P forms angle PWA with the vertical meridional plane, and longitudinal projection PL of pivot axis P forms angle PLA with a plane perpendicular to the horizontal and vertical meridional planes.

When lateral projection angle PWA and longitudinal projection angle PLA are equal, the magnitude of angles PWA and PLA are equal to half of the selected chord angle CA of wings38in the stowed position. The resultant angle PA, as depicted byFIGS.4A and4B, inclines pivot axis P laterally outward from body24and longitudinally forward towards nose20to permit wings38to deploy from a stowed position with a nonzero chord angle to a neutral deployed position in which wings38extend parallel to a horizontal meridional plane. Furthermore, when pivot axis P is inclined laterally outward and longitudinally forward, wing tips60are disposed between lugs54(i.e., the proximal end of wing38R) and nose20in the stowed position, and rotate aft about pivot axis P towards tail section18to transition to the deployed position.

Alternatively, pivot axis P can be inclined laterally outward from body24and longitudinally aft towards tail section18to permit wing tips60to be disposed between lugs54and tail section18in the stowed position. Contrary to the prior embodiment, wings38in this embodiment rotate wing tips60forward about pivot axis P towards nose20to transition to the deployed position. The longitudinal projection angle PLA of this embodiment are angled towards tail section18, or in a direction opposite the longitudinal projection angle depicted byFIG.4B.

In other embodiments, lateral projection angle PWA can be greater than longitudinal projection angle PLA to provide improved deployment of wings38and to reduce a width of slots42. However, when lateral projection angle PWA is greater than longitudinal projection angle PLA, respective chord lines C of wings38form non-zero angles with the horizontal meridional plane of projection10in the deployed position and, thus, form non-zero angles of attack. The angle of attack of wings38can be counteracted by orientating lug54at an angle relative to chord line C when viewed from the wing tip towards the lug end of wing38. For instance, the angle of lug54relative to chord line C can be equal to one half of the difference between the lateral projection angle PWA and longitudinal projection angle PLA.

Lugs54can be coupled to mount56using any suitable method that results in an inclined pivot axis P as described above. In some embodiments, lug54is restrained between mount56and bushing62with fastener64. In this instance, bushing62includes collar66and flange68extending perpendicularly outward from collar66relative to pivot axis P. Collar66has a cylindrical exterior surface and bore that is concentric with pivot axis P. The collar bore forms a sliding or location fit with a cylindrical shaft of fastener64. Flange68has parallel surfaces68A and68B. Surface68B is opposed to and abuts surface54B of lug54, which is parallel to surface56A and extends along a side of lug54opposite surface56A. Surface68A forms a side of flange68that is opposite and parallel to abutting surface68B and bears directly against a head of fastener64or washer70disposed between surface68B and the head of fastener64. Fastener64may have external threads at an end opposite the fastener head to engage corresponding internal threads within a mating bore of mount56. With this arrangement, it is evident that a torque applied to fastener64about pivot axis P secures washer70, bushing62and lug54to mount56. To facilitate free rotation of wing38about pivot axis P, a length of collar66measured from and perpendicular to surface68B of bushing62is larger than a thickness of lug54measured between surfaces54A and54B. Thus, a clearance between wing lug54and opposing surfaces of mount56and bushing62permit free rotation of wing38about pivot axis P. Limiting this clearance or gap between flange68and mount56ensures aerodynamic performance of wings38and precise control of wings38during deployment.

Since pivot58permits wings38to rotate freely about pivot axis P, wings38are restrained in the stowed position using a mechanical latch (not shown) of known design. For instance, wings38can be restrained by a pin extending into a recess within respective tips of wings38, which can be retracted by a change in centrifugal force on wings38or by an electrical or pneumatic actuation means. With the mechanical latch, wings38can be restrained during an initial portion of the trajectory, being deployed only after projectile10is stabilized.

In another exemplary embodiment, pivot58A is depicted byFIGS.5A and5B, which are cross-sectional views taken through starboard wing38R, lug54, and mount56. As withFIGS.4A and4B, the cross-sectional plane ofFIG.5Ais parallel to plane A-A shown inFIG.1, and the cross-sectional plane ofFIG.5Bis perpendicular to plane A-A and extends along longitudinal axis12. Pivot58A functions in essentially the same manner as pivot58except for certain features of the pivot as described below.

Pivot58A includes lug54disposed between washer plate72and bushing74, and coupled to mount56via fastener75, which extends through respective bores of bushing74, lug54, washer plate72and into and a threaded hole of mount56. In a manner similar to pivot58, pivot58A permits starboard wing38R to transition from a stowed position within body24to a deployed position extending outward from body24by rotating about pivot axis P. Pivot axis P can be inclined laterally outward and longitudinally forward to permit wing tips60to be disposed between lugs54and nose20in the stowed position. Alternatively, pivot axis P can be inclined laterally outward from body24and longitudinally aft towards tail section18to permit wing tips60to be disposed between lugs54and tail section18in the stowed position. Accordingly, the magnitudes of lateral projection angle PWA and longitudinal projection angle PLA can be selected in the same manner as pivot58to achieve a stowed position for wings38R in which chord line C of wing38R forms chord angle CA as described with respect to pivot58.

In this embodiment, bushing74includes flange76extending outward from collar78. Collar78extends perpendicularly from flange76having a cylindrical exterior surface parallel to pivot axis P. Bore80extends through bushing74and is concentric to the cylindrical exterior surface of collar78. A centerline axis of bore80is aligned with and parallel to pivot axis P. Flange76extends from an end of collar78in a radially outward direction relative to the centerline axis of bore80and defines parallel surfaces76A and76B that are normal to pivot axis P and the centerline axis of bore80. At an end distal from flange76, collar78includes rabbet82defined by cylindrical surface82A and end face82B. Rabbet82is adapted to receive washer plate72. Moreover, bore80can include a counterbore or chamfer to accommodate a head of fastener75. In the embodiment shown inFIGS.5A and5B, fastener75is flat head machine screw. As such, the angled surface of the fastener head abuts a chamfered surface of bore80.

Washer plate72includes parallel surfaces72A and72B spaced apart to define a thickness of washer plate72. Washer bore84extends perpendicularly through washer plate72from surface72A to surface72B and is sized to accommodate cylindrical surface82A of rabbet82.

Mount56defines surface56A normal to pivot axis P and includes threaded hole86adapted to receive fastener75and counterbore88adapted to receive cylindrical surface82A of collar78.

Lug54defines parallel surfaces54A and54B that are spaced to define a lug thickness. Lug bore90is cylindrical and extends through lug54from surface54A to surface54B. Lug bore90may include a chamfer to provide clearance to a fillet of bushing74between flange76and collar78.

As assembled and shown inFIGS.5A and5B, washer plate surface72A abuts mount surface56A, and washer plate surface72B abuts rabbet end face82B. The head of fastener75engages surfaces of the bushing bore chamfer and thereby develops a clamping force through bushing collar78, washer plate72, and mount56. Alignment of mount56, washer plate72, and bushing74is provided by cylindrical surface82A of rabbet82, which is adapted to engage mount counterbore surface88and washer plate bore84. The relative dimensions between cylindrical surface82A and mount hole counterbore88as well as between cylindrical surface82A and washer plate bore84can be selected to provide a locational clearance fit, a locational transition fit, or a locational interference fit as defined by American National Standard Institute (ANSI) B4.1-1967.

With this assembly, the perpendicular distance between flange surface76B and rabbet face82B, or distance D, can be greater than or equal to lug thickness T to provide clearance between lug54and respective components of pivot58A. Furthermore, the diameters of lug bore90and the exterior cylindrical collar surface can be selected to provide a locational clearance fit, a locational transition fit, or a locational interference fit as is known in the art. Using this assembly, starboard wing38R is coupled to body24at pivot58A, and can be stowed within body24of projectile10with a non-zero chord angle CA while deploying to a different chord angle orientation.

The foregoing embodiments rely on angled planar surfaces of the wing lug abutting corresponding components of the pivot, or planar contact, to guide the wing from an angled stowed position to a deployed position. While the angled orientation of these planar surfaces permit the wing to transition from an angled stowed position to a deployed position, the motion between the stowed and deployed positions cannot deviate from the path defined by pivot axis P and planar surfaces of mount56and lug54. In order to provide a greater amount of control over the motion of the wing from the stowed position to the deployed position, cam followers fixed to the body of the projectile in conjunction with a cam groove and spherical bearing surface can be used to define an orientation of the wing along the deployment path. Alternatively, cam followers fixed to the wing lug can be used in conjunction with a spherical bearing surface and cam grooves on the projectile body or mount to define the orientation of the wing along the deployment path. Pivot58B, as described below, is an exemplary embodiment utilizing cam followers affixed to the projectile body. Although, it will be understood that the same techniques are applicable to embodiments have cam followers fixed in space with respect to the wing lug.

Pivot58B utilizes point contacts provided by cam followers affixed to the projectile body and paired with a spherical bearing to guide the orientation of wings38from the stowed position to the deployed position.FIG.6Ais an isometric view showing a sectional plane cutting through pivot58B that looks upward towards wings38and aftwards towards tail section18(seeFIG.1).FIG.6Bis a forward-looking isometric view showing a sectional plane cutting through projectile10along a position aft of pivots58B. To illustrate both deployed and stowed wing positions,FIGS.6A and6Bdepict starboard wing38R in the stowed position, having the tip of starboard wing38R in the forward stowed position between lug100and nose20(not shown inFIG.6A) and depict port wing38L is in the deployed position extending away from body24. While the following describes pivot58B with respect to starboard wing38R, the pivot for port wing38L will be functionally identical to the pivot described for starboard wing38R except that certain features will be mirrored with respect to the vertical plane of projectile10(i.e., the X-Y plane of coordinate system13).

As with the above described embodiments, starboard wing38R extends in a longitudinal dimension from lug100to a wing tip (not shown) and along chord line C (not shown) defined as the linear distance from the leading edge to the trailing edge of starboard wing38R. Lug100is disposed between bushing102and washer plate104and is secured to mount56via fastener106. Lug100defines parallel surfaces100A and100B, which can be recessed into lug100as shown or can form upper and lower surfaces of lug100generally corresponding to the upper and lower surfaces, respectively, of starboard wing38R. Lug100includes bore108having a centerline that extends perpendicularly through lug100from surface100A to surface100B. The walls of bore108are contoured to define a spherical bearing surface.

Bushing102includes flange110extending outward from an end of collar112. Surfaces110A and110B of flange110are parallel to each other, and each of surfaces110A and110B is normal to a centerline axis of collar112. Collar112extends perpendicularly from flange110along its centerline axis. At an end of collar112distal from flange110, collar112includes rabbet114defined by cylindrical face114A and end face114B. The exterior surface of collar112forms a spherical bearing surface adapted to mate with the spherical bearing surface of lug bore108. Together the spherical bearing surfaces of lug bore108and collar112form spherical bearing115. Bore116extends through flange110and collar112of bushing102along the centerline axis of collar112. Like bore80, bore116can be cylindrical, and an end of bore116can include a counterbore or chamfer to accommodate a head of fastener106.

Washer plate104includes parallel surfaces104A and104B spaced apart to define a washer plate thickness. Washer plate bore118extends perpendicularly through washer plate104from surface104A to surface104B and is sized to accommodate cylindrical surface114A of rabbet114.

Mount56has the same features as described with respect to the previously described embodiments (e.g., as shown inFIGS.5A and5B). However, in this embodiment, surface56A abuts washer plate surface104A and receives cylindrical surface114A of rabbet114in counterbore88.

As assembled, washer plate surface104A abuts mount surface56A, and washer plate surface104B abuts rabbet end face114B. The head of fastener106engages chamfered surfaces of bore116and thereby develops a clamping force through bushing collar112, washer plate104, and mount56. Alignment of mount56, washer plate104, and bushing102is provided by cylindrical rabbet surface114A adapted to engage counterbore surface88and washer plate bore118. The relative dimensions between cylindrical surface114A and mount hole counterbore88as well as between cylindrical surface114A and washer plate bore118can be selected to provide a locational clearance fit, a locational transition fit, or a locational interference fit in the same way as the embodiment depicted byFIGS.5A and5B. To allow spherical bearing115freedom of rotational movement, bushing collar112and lug100are sized such that distance D is larger than lug thickness T in which distance D is the perpendicular distance measured between washer plate surface104B and bushing flange surface110B, and lug thickness T is the perpendicular distance between lug surfaces100A and100B. With this arrangement, clearance exists between lug surface100A and washer plate surface104B and between lug surface100B and flange surface110B.

Spherical bearing115couples lug100, and therefore, wing38R to body24at mount56. Translational movements of lug100relative to body24are restrained by the spherical bearing interface while rotational movements are permitted. In order to better understand these rotational movements and how each are restrained, pivot coordinate system120, defined by mutually orthogonal axes, can be defined for starboard wing38R. The X-axis of pivot coordinate system120is collinear with pivot axis P, which in turn may be angled as described previously with respect to other embodiments. The Z-axis of pivot coordinate system120extends parallel to a longitudinal dimension of wing38R towards wing tip60of starboard wing38R. The Y-axis of pivot coordinate system120extends parallel to chord line C of wing38R, or in other words, extends along the chordwise dimension of starboard wing38R. While coordinate system120, as shown inFIG.6A, is offset from lug100for clarity, the origin of coordinate system120can be located anywhere along pivot axis P. When pivot axis P is angled radially outward and axially forward and wing38R is in the stowed position, the Z-axis of pivot coordinate system120extends towards nose20of projectile in a downward direction (i.e., towards longitudinal axis12with wings in a high-mount configuration), and the Y-axis of pivot coordinate system120extends laterally outward in a downward direction. Additionally, pivot coordinate system120is local to starboard wing38R and, thus, remains stationary relative to starboard wing38R as wing38R rotates from the stowed position to the deployed position.

Using pivot coordinate system120, the spherical bearing formed by lug bore108and collar112permits rotation about pivot axis P, or the X-axis of pivot coordinate system120, as well as the Y-axis and the Z-axis of pivot coordinate system120. To restrain the Y-axis and Z-axis rotations, at least two cam followers are used in conjunction with a cam groove formed in a peripheral side face of lug100in the manner described below.

For example, pivot58B can include cam follower122and cam follower124(seeFIG.6B) restrained within cam groove126formed in peripheral side surface125of lug100. Peripheral side surface125extends between and joins lug surfaces100A and100B and forms a radially outer peripheral surface of lug100relative to pivot axis P (and the X-axis of pivot coordinate system120). In this example, cam follower122is positioned along the Y-axis of pivot coordinate system120, and cam follower124is positioned along the Z-axis of pivot coordinate system120, each with the wing in the stowed position. Each of cam followers122and124is fixed relative to body24by a recess formed by body24or by a separate mount affixed to body24. For instance, cam follower122is restrained relative to body24via follower mount128, and cam follower124is restrained relative to body24via a recess within body24itself (not shown). With this arrangement, cam followers122and124remain stationary as starboard wing38R pivots from the stowed position to the deployed position. Moreover, cam followers122and124working in conjunction with cam groove126restrain rotation of wing38R about the Y-axis and the Z-axis of pivot coordinate system120. While cam followers122and124are positioned along the Y-axis and the Z-axis, respectively of pivot axis120in the stowed position, other positions could be used so long as cam followers122and124are not positioned along the same axis (i.e., cam followers122and124are noncollinear). Furthermore, as shown, cam follower122is angularly spaced from cam follower124by 90 degrees. Although, cam followers122and124can be angularly spaced by more than or less than 90 degrees.

Cam groove126defines upper guiding surface126A, lower guiding surface126B, and base surface126C. Guiding surfaces126A and126B are spaced from each other to accommodate a diameter or thickness of cam followers122and124. Base surface126C joins upper guiding surface126A to lower guiding surface126B to complete cam groove126. The groove thickness measured between upper guide surface126A and lower guide surface126B is sized to form a sliding or location fit with each of cam followers122and124. Base surface126C is offset into lug100a distance from the peripheral surface to provide clearance to each of cam followers122and124. With this arrangement, cam followers122and124slide within groove126as starboard wing38R pivots from the stowed position to the deployed position.

To mimic the deployment path of pivots58and58A, guiding surfaces126A and126B of cam groove126would extend parallel to surfaces100A and100B for the entire length of groove126. In this arrangement, however, cam follower122slides along a first portion of groove126while cam follower124slides along a second portion of groove126, each portion of groove126having a stowed position and a deployed position for each cam follower. If the deployment angle is 90 degrees and if cam follower122is spaced from cam follower124by 90 degrees, the deployed position of cam follower122along groove126corresponds to the stowed position of cam follower124along groove126.

Guiding surfaces126A and126B can deviate upward (i.e., in a positive X-axis direction of pivot axis120) or downward (i.e., in a negative X-axis direction of pivot axis120), starboard wing38R will deviate from the path followed by a planar contact pivot. For instance, when guiding surfaces126A and126B deviate upward or downward along a portion of groove126corresponding to cam follower122, starboard wing38R rotates about the Z-axis of pivot coordinate system120in the stowed position. Similarly, when guiding surfaces126A and126B deviate upward or downward along a portion of groove126corresponding to pin124, starboard wing38R rotates about Y-axis of pivot coordinate system120in the stowed position. Depending on the deployment angle of starboard wing38R, the deviations of guide surfaces126A and126B can produce: 1) rotation about the longitudinal dimension of the wing (i.e., the Z-axis of pivot coordinate system120), 2) tilt of the wing such that the wing tip is displaced along the X-axis of pivot coordinate system120relative to lug100, or 3) a combination of longitudinal rotation and wing tilt, each defined as a function of deployment angle.

FIG.6Cdepicts lug100of starboard wing38R with cam groove126, andFIG.6Dis a developed view of cam groove126employed on starboard wing38R inFIGS.6A-6C. With continued reference toFIGS.6C and6D, cam follower122slides within cam groove126between location A and location B defining first portion130of groove126. Cam follower124slides within groove126between location B and location C defining second portion132of groove126. In first portion130, surfaces126A and126B deviate downward (i.e., towards lug surface100B) relative to grooves lines parallel to surfaces100A and100B represented by dashed lines134. This region coincides with location A, or the stowed position of follower122. As a result, starboard wing38R forms chord angle CA in the stowed position such that leading and trailing edges44and46of starboard wing38R are immediately adjacent to an inner surface of body24as disclosed in prior embodiments. Second portion132remains parallel to lug surfaces100A and100B to produce a deployment path similar to planar contact embodiments of pivot58. Using this profile for cam groove126, first portion130of groove126can maintain a larger chord angle CA than would otherwise be possible with planar contact pivots by having surfaces126A and126B deviate downward relative to dashed lines134. Accordingly, starboard wing38R can be stored with chord angle CA and be deployed to a horizontal orientation (i.e., a chord line parallel to a horizontal plane of projectile10). Additionally, deployment of starboard wing38R can maintain a higher chord angle CA than would otherwise by possible over an initial portion of the deployment path to facilitate deployment of wing38R through slot42(seeFIG.1). For example, pivot58B can deploy wing38R along a path that maintains a constant chord angle CA or that changes at a lesser rate relative to an intermediate portion of the deployment path over an initial portion of the deployment path corresponding to wing38R passing through slot42to facilitate smaller slot geometry than would be possible with planar contact pivots.

However, other cam groove profiles can be selected for other purposes. In each case, the shape or contour of cam groove126can be defined by selecting a desired chord angle CA as a function of deployment angle. For a given orientation of pivot axis P and fixed locations of followers122and124, control points of cam groove126can define a smooth and continuous curve corresponding to each desired chord angle CA and deployment angle point. Surfaces126A and126B conform to the control point curve, each being spaced therefrom to define the groove thickness.

In another exemplary embodiment depicted byFIG.7A, pivot58C utilizes point contact along cam grooves formed within lug surfaces100A and100B paired with a spherical bearing to guide the orientation of wings38from the stowed position to the deployed position.FIG.7Ais an isometric view showing a sectional plane intersecting port wing38L, lug100, washer plate102, bushing104, and fastener106, which include the same features described with respect to the embodiment depicted byFIGS.6A-6Dwith certain exceptions and/or additions. For instance, instead of restraining rotational moments about spherical bearing115with groove126and cam followers122and124alone, lug100can alternatively or additionally include one or more grooves136formed by a recess within surface100A and one or more grooves138formed by a recess within surface100B. As with the previously described cam-guided pivot embodiment, thickness T of lug100is less than distance D between bushing flange surface110B and washer plate surface104B to form gaps between lug surfaces100A and100B and washer plate104and bushing flange110, respectively.

Like starboard wing38R, rotational movements of port wing38L are understood in reference to pivot coordinate system135defined by three mutually orthogonal axes. Pivot coordinate system135is like coordinate system120defined for starboard wing38R. However, pivot coordinate system135is local to port wing38L. The X-axis of coordinate system135is collinear with pivot axis P of wing38L. The Z-axis extends parallel to a longitudinal dimension of port wing38L. The Y-axis extends parallel to chord line C, or a chord-wise direction, of wing38L and, in the deployed position shown byFIG.7A, extends in an axial direction towards trailing edge46of port wing38L.

Each of grooves136and138follows an arc about the centerline axis of lug bore108that is aligned with the X-axis of pivot coordinate system135. The depth of each groove136is measured as the perpendicular distance from lug surface100A to the bottom-most point of groove136at a particular position along the arc length of groove136. Similarly, the depth of each groove138is measured as the perpendicular distance from lug surface100B to the bottom-most point of groove138at a particular position along the arc length of groove138. The depth of grooves136and138varies along respective arc lengths to vary the orientation of port wing38L as wing38L moves from the stowed position to the deployed position.

In the embodiment depicted byFIG.7A, washer plate104retains four pins140(only two pins140are shown) equally-spaced about the centerline axis of washer plate bore118and the X-axis of pivot coordinate system135. Because four pins140are used and the deployment angle is at least 90-degrees in the disclosed embodiment, pins140form two pairs of 180-degree-spaced pins, each pair of pins140disposed along a different common radius. This arrangement retains independent control of each of the four pins140. Otherwise, if all four pins140are disposed along a common radius, the stowed position of one of the pins would dictate the deployed position of an adjacent pin140since portions of groove136corresponding to each pin140would overlap. This would also be true for different numbers of pins with corresponding deployment angle ranges (e.g., three pins with at least a 120-degree deployment sweep or five pins with at least 72-degree deployment sweep). Bushing106retains another four equally-space pins142(only three pins142are shown). Pins142also form two pairs of 180-degree-spaced pins, each pair disposed along a different common radius relative to the centerline axis of bushing bore116. Each of pins140and pins142have a cylindrical shape terminating with a hemispherical free end adapted to engage one of the grooves136and138in lug surfaces100A and100B.

While four pins140and four pins142are used in the present embodiment, a lessor or greater number of pins140and142could be used. For instance, embodiments using two of each of pins140and142rely on spherical bearing115to establish the orientation of wing38L. However, since manufacturing tolerances of spherical bearing115may permit undesirable deviations from the intended deployment path, arrangements of at least three pins140and at least three pins142can be used to define the chord angle CA of wing38L along the deployment path. While spherical bearing115couples lug100of port wing38L to mount56, the orientation of wing38L along the deployment path can be limited by pins140and142for which tighter manufacturing tolerances are more-easily obtained. Increasing the number of pins140and pins142, such as depicted byFIG.7A, reduces the difference in restraining moment arm associated with a rotational moment applied about an axis intersecting pins140and pins142and a rotational moment applied about an axis extending between pins140and pins142. Accordingly, increasing the number of pins140and pins142improves stability of pivot58C.

The profiles of each of cam grooves136and138can be determined using method200as follows. First, the desired chord angle CA is selected as a function of deployment angle in step202. The chord angle CA to deployment angle relationship can be defined using a polynomial equation in some embodiments. In other embodiments, this relationship can be defined using discrete control points along the deployment path. For example, Table 1 illustrates a set of control points defining the deployment path of port wing38L in which, for each deployment angle, a given chord angle CA has been selected. In the example shown by Table 1, the chord angle CA remains constant or decreases at a lesser rate through initial and final portions of the deployment path relative to an intermediate portion of the deployment path. During the initial portion of the deployment path, maintaining chord angle CA within a relatively narrower range permits slots42through projectile body24to be narrower than a planar contact pivot. Moreover, maintaining chord angle CA within a relatively narrow range at the final portion of the deployment path allows for variation in the assembly or manufacturing of pivot58C without unduly affecting the aerodynamic performance of projectile10.

TABLE 1Control Points for Example Deployment PathAngle of WingDeploymentChord Angle CA02010183010456603751900

In step204, an orientation of pivot axis P can be determined based on the desired stowed and deployed positions of port wing38. In a manner similar to the planar contact pivot embodiments (e.g., pivots58and58A), the orientation of pivot axis P is defined by lateral projection angle PWA of pivot axis P and by longitudinal projection angle PLA of pivot axis P. When lateral projection angle PWA equals longitudinal projection angle PLA, the magnitude of each of angles PWA and PLA equals half the selected chord angle CA in the stowed position. Arrangements with equal projection angles PWA and PLA also deploy to a neutral wing position (i.e., zero chord angle CA) at a 90-degree deployment angle sweep. Moreover, it can be seen that different combinations of lateral projection angle PWA, longitudinal projection angle PLA, and total deployment angle sweep will result in different chord angles CA in the stowed and deployed positions, which can be tailored to a particular application.

At step206, a set of cam follower locations are selected. The set of cam followers includes at least two pins140and two pins142, if spherical bearing115is used to define a third restraint location. If the orientation of wing38L is to be restrained without relying on spherical bearing, the set of cam follower positions includes at least three pins140and at least three pins142. In the example shown byFIGS.7A and7B, four pins140and four pins142are selected, but more pins140and142could be used. It is beneficial to select equal numbers of pins140and pins142so that each of pins140can engage one of cam grooves136opposite one of pins142to minimize bending within lug100associated with offsetting pins142between adjacent pins140. Furthermore, the location of each cam follower corresponds to a free end of the cam follower. In the embodiment depicted byFIGS.7A and7B, the location of each cam follower is fixed relative to mount56and defined using X, Y, Z coordinates in a coordinate system fixed with respect to mount56. The origin of the mount coordinate system has an origin on pivot axis P, a Y-Z plane coincident with and aligned with one of lug surfaces100A and100B, and an X-axis extending away from the lug surface along pivot axis P. For instance, coordinate system150is associated with lug surface100A having XYZ axes aligned with coordinate system135when wing38L is in the stowed position. Since port wing38L is depicted in the deployed position, coordinate system150, as depicted inFIG.7B, has an origin that is offset from the origin of coordinate system135for explanatory purposes only. As port wing38L deploys, coordinate system150remains fixed relative to mount56while coordinate system135remains fixed relative to port wing38L resulting in the relative orientations of coordinate systems135and150depicted inFIG.7B.

where:X, Y, and Z are the X, Y, and Z coordinates in mount coordinate system150X″, Y″, and Z″ are the X, Y, and Z coordinates in pivot coordinate system135θ is the wing deployment angle (i.e., rotation about the X-axis), andϕ is the chord angle CA (i.e., rotation about

As a result, the transformed cam follower locations are defined as a function of the desired chord angle CA and deployment angle established in step202and define a groove path for each cam follower. Subsequently, grooves136and138are defined in lug surfaces100A and100B according to respective groove paths (e.g., grooves136shown inFIG.7B) in step210.

While planar contact pivots58and58A permit wings38to be stowed with a nonzero chord angle CA, pivots58B and58C additionally allow the deployment path of wings38to be tailored to minimize a size of slots14. Additionally, a deployment path defined by pivots58B and58C can be tailored to control the path of the wing tip during deployment. In some embodiments, it may be undesirable for the wing tip to exceed a threshold vertical displacement with respect to the lug as the wing moves from the stowed position to the deployed position. For example, some projectiles may include multiple sets of wings38, one set above the horizontal meridional plane and one set below the horizontal meridional plane. In these circumstances, the upper set of wings may interfere with the lower set of wings during deployment if the wing tip paths of each set intersect. To alleviate wing tip interference, the wing tip path can be established by selected desired chord angle CA values as a function of deployment angle that satisfy the wing tip path limit for a given length of wing.

FIG.9is a graph illustrating the wing tip paths A and B for wing38L equipped with a planar contact pivot (e.g., pivot58or pivot58A) and a cam-guided pivot (e.g., pivot58B or58C), respectively, the cam-guided pivot having a cam groove path tailored to reduce the maximum vertical displacement magnitude of the wing tip during deployment. For example, groove path126associated with pivot58B or grooves136and138associated with pivot58C can be configured to reduce maximum vertical displacement magnitude of wing tip60as described byFIG.9. The ordinate axis ofFIG.9indicates horizontal displacement of the wing tip relative to the stowed position that increases in the aftward direction along longitudinal axis12of projectile10towards tail section18. The abscissa axis ofFIG.9indicates vertical displacement of wing tip60relative to a horizontal wing orientation or level orientation in the stowed position. In embodiments having a high-mounted wing configuration, negative vertical wing tip displacement indicates wing tip displacement towards longitudinal axis12of projectile10.

Path A illustrates an exemplary wing tip path for a wing having a planar contact pivot. In this example, the stowed chord angle CA is 20 degrees and the deployed chord angle is 0 degrees, as provided by Table 1 above. Pivot axis P associated with the above stowed and deployed chord angles has longitudinal projection angle PLA equal to 10 degrees and lateral projection angle PWA equal to 10 degrees. For a given wing length equal to 400 millimeters, the wing tip sweeps through a path that exceeds 40 millimeters below the stowed position as shown by Path A.

Path B illustrates another exemplary wing tip path having the same stowed and deployed positions as the wing of Path A except, instead of using a planar contact pivot, this wing utilizes cam-guided pivot58C that has a wing tip path associated with desired chord angles defined according to Table 1 above. Using this arrangement, the wing tip path does not exceed 35 millimeters below the stowed position as the wing moves from the stowed position to the deployed position.

Discussion of Possible Embodiments

A projectile according to an exemplary embodiment of this disclosure, among other possible things includes a body and a deployable wing coupled to the body and enclosed by the body in a stowed position. A linear distance from a leading edge to a trailing edge of the wing defines a chord line. In the stowed position, the chord line forms an angle with a plane containing the chord line and extending parallel to a parallel direction of the deployable wing in the deployed position.

A further embodiment of the foregoing projectile, wherein the deployable wing can be coupled to the body at a pivot.

A further embodiment of any of the foregoing projectiles that include a pivot, wherein rotation of the deployable wing about the pivot can move the deployable wing from the stowed position to the deployed position.

A further embodiment of any of the foregoing projectiles that includes a pivot, wherein a longitudinal plane can extend along a longitudinal axis of the body, and wherein a lateral plane can extend transversely to the body perpendicularly to the longitudinal plane, and wherein the pivot can define a rotational axis having a first projection in the lateral plane forming a first angle with respect to the longitudinal plane and a second projection in the longitudinal plane forming a second angle with respect to the lateral plane.

A further embodiment of any of the foregoing projectiles that includes a pivot, wherein the wing can extend from a proximal end to a distal end, and wherein the proximal end is coupled to the body at the pivot.

A further embodiment of any of the foregoing projectiles, wherein the body can include 1) a nose, 2) a tail opposite the nose along the longitudinal axis of the body, and 3) a plurality of stabilizers extending from the tail.

A further embodiment of any of the foregoing projectiles having a proximal end of the deployable wing coupled to the body at a pivot, wherein the distal end of the deployable wing in the stowed position can be between the proximal end and a nose of the body A further embodiment of any of the foregoing projectiles having a proximal end of the deployable wing coupled to the body at a pivot, wherein the distal end of the deployable wing in the stowed position can be between the proximal end and a tail of the body.

A further embodiment of any of the foregoing projectiles having a pivot defining a rotational axis, wherein the rotational axis can be angled laterally outward from the body and longitudinally forward towards a nose of the body.

A further embodiment of any of the foregoing projectiles having a pivot defining a rotational axis, wherein the rotational axis can be angled laterally outward from the body and longitudinally aft towards a tail of the body.

A further embodiment of any of the foregoing projectiles can further include a lug at a proximal end of the airfoil that defines a first planar surface normal to a rotational axis of a pivot coupling the wing to the body.

A further embodiment of any of the foregoing projectiles can further include a mount extending from an interior surface of the body that defines a second planar surface normal to a rotational axis of a pivot coupling the wing to the body.

A further embodiment of any of the foregoing projectiles that include a lug defining a first planar surface and a mount defining a second planar surface, wherein the pivot includes a shaft extending through aligned bores in the lug and the mount.

A further embodiment of any of the foregoing projectiles can further include a bushing.

A further embodiment of any of the foregoing projectiles that include a bushing, wherein the bushing can include a collar extending through a bore of the lug and along a shaft.

A further embodiment of any of the foregoing projectiles that include a bushing, wherein the bushing can include a flange extending perpendicularly from a collar of the bushing.

A further embodiment of any of the foregoing projectiles that includes a bushing with a flange, wherein the lug can be disposed between the flange and the mount, and wherein a gap defined between the flange and the mount is greater than a thickness of the lug between the flange and the mount.

A further embodiment of any of the foregoing projectiles that includes a bushing, wherein the shaft is a shank of a threaded fastener securing the busing to the mount and retaining the lug of the airfoil between the bushing and the mount.

A further embodiment of any of the foregoing projectiles, wherein the chord angle can be at least 5 degrees.

A further embodiment of any of the foregoing projectiles, wherein the chord angle can be at least 10 degrees.

A further embodiment of any of the foregoing projectiles, wherein the body can define a slot through which the airfoil extends in the deployed position.

A further embodiment of any of the foregoing projectiles that includes a body defining a slot, wherein the slot can be tapered along a longitudinal direction of the body and in a direction moving away from a pivot coupling the wing to the body.

A projectile according to another exemplary embodiment of this disclosure, among other possible things includes a body and a deployable wing coupled to the body. In a stowed position of the wing, the body encloses the wing. In a deployed position, the wing extends outward from the body.

A further embodiment of the foregoing projectile, wherein the wing can be coupled to the body at a pivot defining an axis of rotation.

A further embodiment of any of the foregoing projectiles that include a pivot, wherein the axis of rotation can be angled laterally outward from the body and longitudinally forward towards a nose of the body.

A further embodiment of any of the foregoing projectiles that include a pivot, wherein the axis of rotation can be angled laterally outward from the body and longitudinally aft towards a tail of the body.

A further embodiment of any of the foregoing projectiles, wherein the wing can be offset from a meridional plane of the projectile.

A further embodiment of any of the foregoing projectiles that include a pivot, wherein a lateral projection of the axis of rotation forms a first angle and a longitudinal projection of the axis of rotation forms a second angle that is equal to the first angle.

A further embodiment of any of the foregoing projectiles that include a pivot, wherein a lateral projection of the axis of rotation forms a first angle and a longitudinal projection of the axis of rotation forms a second angle that is less than the first angle.

A further embodiment of any of the foregoing projectiles that include a pivot, wherein the airfoil can include a lug interfacing with the pivot.

A further embodiment of any of the foregoing projectiles that include a pivot and a lug, wherein the lug can form an angle with a chord line of the airfoil.

A further embodiment of any of the foregoing projectiles that include a pivot and a lug, wherein the lug can be parallel to a chord line of the airfoil.

A projectile according to another exemplary embodiment of this disclosure, among other possible things includes a body and a deployable wing coupled to the body. In a stowed position of the wing, the body encloses the wing. In a deployed position, the wing extends outward from the body. The wing couples to the body at a pivot defining an axis of rotation. Rotation of the wing about the axis of rotation translates the wing from the stowed position to the deployed position. A lateral projection of the axis of rotation forms a first angle that is equal to a second angle formed by a longitudinal projection of the axis of rotation. The sum of the first and second angles equals a chord angle formed by a chord line of the wing with a meridional plane of the projectile in the stowed position.

A projectile according to another exemplary embodiment of this disclosure, among other possible things includes a body and a deployable wing coupled to the body. In a stowed position of the wing, the body encloses the wing. In a deployed position, the wing extends outward from the body. The wing couples to the body at a pivot defining an axis of rotation. Rotation of the wing about the axis of rotation translates the wing from the stowed position to the deployed position. A lateral projection of the axis of rotation forms a first angle that is greater than a second angle formed by a longitudinal projection of the axis of rotation. The sum of the first and second angles equals a chord angle formed by a chord line of the wing with a meridional plane of the projectile in the stowed position. The wing includes a lug interfacing with the pivot that forms a lug angle with the chord line.

A projectile according to another exemplary embodiment of this disclosure, among other possible things includes a body and a deployable wing coupled to the body. In a stowed position of the wing, the body encloses the wing. In a deployed position, the wing extends outward from the body. The wing couples to the body at a pivot defining an axis of rotation. Rotation of the wing about the axis of rotation translates the wing from the stowed position to the deployed position. A lateral projection of the axis of rotation forms a first angle that is less than a second angle formed by a longitudinal projection of the axis of rotation. The sum of the first and second angles equals a chord angle formed by a chord line of the wing with a meridional plane of the projectile in the stowed position. The wing includes a lug interfacing with the pivot that forms a lug angle with the chord line.

A projectile according to another exemplary embodiment of this disclosure includes, among other possible things, a nose, a body, and a tail boom opposite the nose along a longitudinal axis of the body. The projectile further includes a plurality of stabilizers extending from a mount on the tail boom and a deployable wing coupled to the body at a pivot. Rotation of the deployable wing about the pivot moves the deployable wing from a stowed position to a deployed position. In the stowed or deployed positions, the linear distance from a leading edge to a trailing edge of the deployable wing defines a chord line. In the deployed position, the chord line and a longitudinal dimension of the deployable wing define a reference plane. In the stowed position, the deployable wing is enclosed within the body, and the chord line forms an acute angle with the reference plane.

A further embodiment of the foregoing projectile, wherein a longitudinal plane can extend along the longitudinal axis of the body and a lateral plane can extend transversely to the body and perpendicularly to the longitudinal plane.

A further embodiment of any of the foregoing projectiles, wherein the pivot can define a rotational axis having a first projection in the lateral plane forming a first acute angle with respect to the longitudinal plane.

A further embodiment of any of the foregoing projectiles, wherein the pivot can define a rotational axis having a second projection in the longitudinal plane forming a second acute angle with respect to the lateral plane.

A further embodiment of any of the foregoing projectiles, wherein the deployable wing can extend from a proximal end to a distal end in which the proximal end is coupled to the body at the pivot.

A further embodiment of any of the foregoing projectiles, wherein the distal end of the deployable wing in the stowed position can be between the proximal end of the deployable wing and the nose of the body.

A further embodiment of any of the foregoing projectiles, wherein the distal end of the deployable wing in the stowed position can be between the proximal end of the deployable wing and the tail boom.

A further embodiment of any of the foregoing projectiles, wherein the rotational axis can be angled laterally outward from the body and longitudinally forward towards the nose.

A further embodiment of any of the foregoing projectiles, wherein the rotational axis can be angled laterally outward from the body and longitudinally aft towards the tail boom.

A further embodiment of any of the foregoing projectiles, wherein the projectile can include a lug at the proximal end of the deployable wing that defines a first planar surface normal to the rotational axis.

A further embodiment of any of the foregoing projectiles, wherein the projectile can include a mount extending from an interior surface of the body that defines a second planar surface normal to the rotational axis and opposing the first planar surface.

A further embodiment of any of the foregoing projectiles, wherein the pivot can include a shaft extending through aligned bores in the lug and the mount.

A further embodiment of any of the foregoing projectiles, wherein the pivot can include a bushing.

A further embodiment of any of the foregoing projectiles, wherein the bushing can include a collar extending within the bore of the lug and along the shaft.

A further embodiment of any of the foregoing projectiles, wherein the bushing can include a flange extending perpendicularly from the collar such that the lug is disposed between the flange and the mount.

A further embodiment of any of the foregoing projectiles, wherein a gap defined between the flange and the mount can be greater than a thickness of the lug between the flange and the mount.

A further embodiment of any of the foregoing projectiles, wherein the shaft can be a shank of a threaded fastener securing the bushing to the mount and retaining the lug of the deployable wing between the bushing and the mount.

A further embodiment of any of the foregoing projectiles, wherein the body can define a slot through which the deployable wing extends in the deployed position.

A further embodiment of any of the foregoing projectiles, wherein the slot can be tapered along the longitudinal axis of the body and in a direction moving away from the pivot.

A further embodiment of any of the foregoing projectiles, where the projectile can further include a deployable flow guide coupled to the body at a flow guide pivot.

A further embodiment of any of the foregoing projectiles, wherein the deployable flow guide can be disposed between the deployable wing and the nose.

A projectile according to another exemplary embodiment of this disclosure includes, among other possible things, a nose, a body, and a tail boom opposite the nose along a longitudinal axis of the body. The projectile further includes a plurality of stabilizers extending from a mount on the tail boom, a deployable wing coupled to the body at a pivot, and a mount extending from an interior surface of the body. The deployable wing extends longitudinally from a proximal end to a distal end and extends laterally from a leading edge to a trailing edge. The deployable wing includes a lug at the proximal end of the deployable wing, a lug bore extending through the lug, and a chord line defined by a linear distance from the leading edge to the trailing edge. The deployable wing is configured to rotate about a rotational axis of the pivot from a stowed position to a deployed position. The pivot includes a washer plate disposed between the lug and the mount, a collar extending through the lug bore, a flange extending perpendicularly from the collar, and a rabbet adapted to receive the washer plate. A longitudinal plane extends along a longitudinal axis of the body. A lateral plane extends transversely to the body and perpendicularly to the longitudinal plane. The rotational axis of the pivot forms a first projection in the lateral plane forming a first acute angle with respect to the longitudinal plane and a second projection in the longitudinal plane forming a second acute angle with respect to the lateral plane. In the stowed position, the chord line forms an acute angle with the lateral plane of the projectile.

A further embodiment of the foregoing projectile, wherein the projectile can further include a plurality of followers affixed to the body of the projectile.

A further embodiment of any of the foregoing projectiles, wherein the lug is disposed between the flange of the bushing and the washer plate.

A further embodiment of any of the foregoing projectiles, wherein the projectile can further include a spherical bearing formed by the lug bore engaging an exterior surface of the collar.

A further embodiment of any of the foregoing projectiles, wherein a linear distance measured perpendicularly between opposing surfaces of the washer plate and the flange can be greater than a thickness of the lug.

A further embodiment of any of the foregoing projectiles, wherein each of the plurality of followers can be received in a groove formed within a peripheral surface of the lug radially outward from the lug bore.

A further embodiment of any of the foregoing projectiles, wherein the projectile can further include a first follower engaging the groove at a location that is aligned with the longitudinal axis of the deployable wing in the stowed position.

A further embodiment of any of the foregoing projectiles, wherein the projectile can further include a second follower that is angularly spaced from the first follower about the axis of rotation.

A further embodiment of any of the foregoing projectiles, wherein the first follower can be noncollinear with the second follower.

A further embodiment of any of the foregoing projectiles, wherein the groove can include a first portion bounded by positions of the first follower in the stowed and deployed positions.

A further embodiment of any of the foregoing projectiles, wherein the entirety of the first portion of the groove can extend parallel to a surface of the lug.

A further embodiment of any of the foregoing projectiles, wherein the groove can includes a second portion bounded by positions of the second follower in the stowed and deployed positions.

A further embodiment of any of the foregoing projectiles, wherein the second portion can have at least a segment that extends obliquely to the surface of the lug.

A further embodiment of any of the foregoing projectiles, wherein the projectile can further include a first plurality of followers affixed to the washer plate.

A further embodiment of any of the foregoing projectiles, wherein the projectile can further include a second plurality of followers affixed to the flange.

A further embodiment of any of the foregoing projectiles, wherein each of the first plurality of followers can be received in one or more first grooves formed within a first planar surface of the lug.

A further embodiment of any of the foregoing projectiles, wherein each of the second plurality of followers can be received in one or more second grooves formed within a second planar surface of the lug opposite the first planar surface.

A further embodiment of any of the foregoing projectiles, wherein a first depth of the one or more first grooves can vary along an arc length of the one or more first grooves.

A further embodiment of any of the foregoing projectiles, wherein a second depth of the one or more second grooves can vary along an arc length of the one or more second grooves.

A further embodiment of any of the foregoing projectiles, wherein the one or more first grooves can include at least two first grooves defined along different radii with respect to the lug bore.

A further embodiment of any of the foregoing projectiles, wherein the one or more second grooves can include at least two second grooves defined along different radii with respect to the lug bore.

A further embodiment of any of the foregoing projectiles, wherein the first plurality of followers can include at least three first followers.

A further embodiment of any of the foregoing projectiles, wherein the second plurality of followers can include at least three second followers.