Airborne vehicle with wing extension and roll control

The invention is an airborne vehicle. In detail, the invention includes a main body having a longitudinal, lateral and vertical axis. A pair of wings are pivotally mounted to the main body that are movable about an axis of rotation from a retracted position to an extended position external of the main body along the lateral axis. A linkage assembly for controlling the position of the wings is mounted within the vehicle that includes a guide assembly having an open ended slot aligned with the longitudinal axis thereof. First and second links have their first ends pivotally connected to the wings at a position offset from the axis of rotation of the wings, and the second ends thereof pivotally coupled to each other. A pin is rotatably coupled to the second ends of the first and second links and is movable from a first position within the slot wherein the first and second links are at an acute angle to each other to a second position external of the open end of the slot wherein the first and second links are rotated to a greater angular relationship. A spring is incorporated for urging the first and second links to the greater angular relationship. A latch is incorporated for securing the first and second links in the greater angular relationship after the pin exits the open end of the slot. An actuator is used to move the pin from the first position to the second position and, additionally, along the lateral axis when the pin is in the second position.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The invention relates to the field of airborne vehicles and, in particular, 
to an airborne cruise missile having folded wings that are extended during 
flight and the actuation system therefore. 
2. Description of Related Art 
Modem cruise missiles, such as the Tomahawk, have retractable wings 
allowing internal storage within the bomb bay of the vehicle, typically 
mounted on rotary launchers therein. For example, U.S. Pat. No. 5,035,378 
"Variable Alignment Mechanism" by Joseph P. Spanovich discloses a system 
for extending the wings of a missile by means of a single actuator. The 
wings are pivotally mounted to the fuselage and are coupled to either side 
of a slidable member by means of connecting rods. The slide is guided 
along the longitudinal axis by means of a pin mounted thereto that rides 
in a slot. The actuator moves the member down the slot causing the wings 
to extend. The front end of the slot is expanded such that the pin can 
move slightly sideways so that any tolerance build-up in the mechanism can 
be absorbed insuring that the wings can be fully retracted. U.S. Pat. No. 
5,141,175 "Air Launched Munition Range Extension System And Method" by 
Gordon L. Harris discloses a screw mechanism for extending the wings. 
Japanese Patent No. 404297799 A "Guided Missile" by M. Akiguchi discloses 
a wing actuation system using a single actuator coupled to the wings by 
means of a gear drive system. United Kingdom Patent Application No. 
2154715A "Aerodynamic Mechanism For Missiles" by H. Hutter, et al. 
discloses a system wherein a single actuator operating a cable and pulley 
system is used to extend the wings. U.S. Pat. No. 5,192,037 
"Double-Pivoting Deployment System For Aerosurfaces" by William J. 
Moorefield discloses a system for deploying wings, stored backward along 
the fuselage in the vertical plane, by initially rotating the wings so 
they are horizontal and then extending the wings outward. U.S. Pat. No. 
3,861,627 "Foldable Control Flap Unit, Especially For Rockets" by Rainer 
Schoffl and U.S. Pat. No. 4,659,036 "Missile Control Surface Actuator 
System" by George T. Pinson. Both disclose rocket powered projectiles 
having folded fins that are automatically deployed during flight. U.S. 
Pat. No. 4,351,499 "Double Fabric, Self-Erecting Wing For Missile" by Inge 
Maudal, et al. discloses an extendible fabric covered fin for use on a 
missile. However, none of the above systems provides the ability to 
provide roll control using the same mechanism used for deploying the wings 
and/or fins. 
U.S. Pat. No. 4,029,270 "Mechanical Roll Rate Stabilizer For A Rolling 
Missile" by Byron M. Niemier discloses a gear drive assembly for rotating 
fins on a missile in opposite directions. Great Britain Patent 
Specification No. 790,540 "Improvements Relating To Missiles" by Frank 
Martin, et al. discloses a linkage system for providing both collective 
and counter rotation of airfoils for simultaneous pitch and roll control. 
However, neither provide for storing the airfoils in a retracted position 
for storage purposes prior to flight. U.S. Pat. No. 5,439,188 "Control 
System" by Herbert D. Depew, Jr., et al. uses a single set of opposed fins 
for both pitch and yaw control. The missile is spin stabilized during 
flight and the fins are adjusted during appropriate portions of each 
revolution to provide pitch and yaw control. The problem here is that it 
is only usable on a spin stabilized missile or the like. 
U.S. Pat. No. 3,921,937 "Projectile Or Rocket Preferably With Unfolded Tail 
Unit" by Alfred Voss, et al. discloses a system for deploying stored fins 
on a missile and providing roll and pitch control. However, a separate 
actuation system is used for both functions. U.S. Pat. No. 5,150,861 
"Variable Sweep Side Force Generator And Roll Control Device" by Edwin W. 
Merkel, et al. is of interest in that it discloses a missile having wings 
and a separate vertical fin that can be deployed from a stored position to 
variable positions of deployment for providing both side force and roll 
control. However, this system is simply a single airfoil deployment 
system. 
Thus it is a primary object of the subject invention to provide a wing 
extension system for an airborne vehicle. 
It is another primary object of the subject invention to provide a 
combination wing extension system and roll control system for an airborne 
vehicle. 
It is a further object of the subject invention to provide a combination 
wing extension system and roll control system for an airborne vehicle that 
uses only one actuator. 
It is a further object of the subject invention to provide a combination 
wing extension system and roll control system for an airborne vehicle 
where the roll control is provided by differentially varying the sweep 
angle of each wing. 
SUMMARY OF THE INVENTION 
The invention is an airborne vehicle and, in particular, a cruise missile. 
In detail, the invention includes a main body or fuselage having a 
longitudinal, lateral and vertical axis. The vehicle includes a pair of 
wings pivotally mounted to the main body that are movable about an axis of 
rotation from a retracted position to an extended position. A linkage 
assembly is provided for extending the wings and, after extension, for 
simultaneously increasing the sweep angle of one wing while decreasing the 
sweep angle of the opposite wing to provide roll control. 
In detail, the linkage assembly includes a guide rail having an open ended 
slot aligned with the longitudinal axis of the main body and mounted 
therein. First and second links have their first ends coupled to the wings 
at a position offset from the axis of rotation thereof. Preferably, the 
wings incorporate arms that provide the offset. The second ends of the 
links are pivotally coupled to each other. A pin is rotatably coupled to 
the second ends of the first and second links and which is movable from a 
first position within the slot, wherein the first and second links are at 
an acute angle to each other and the wings are in a retracted position to 
a second position external of the open end of the slot, wherein the first 
and second links are rotated to a greater angular relationship and the 
wings are in an extended position. Preferably, the greater angular 
relationship is slightly over 180 degrees. 
A latch assembly is coupled to the first and second links for securing them 
in the greater angular relationship after the pin exits the open end of 
the slot. An actuator is coupled to one of the links such that it can move 
the pin along the longitudinal axis from the first position, wherein the 
links are at the acute angle, to the second position, wherein the pin is 
free to the slot and the links are in the greater angular relationship. 
The actuator can, additionally, move the first and second links along the 
lateral axis such that the sweep of one wing is increased while the other 
is decreased. This, of course, will decrease the lift produced by the wing 
with the increased sweep and increase the lift from the wing having its 
sweep angle decreased providing the roll control. 
Preferably, the latch assembly is an over center style latch having a 
spring with its ends attached to the first and second links in proximity 
to the second ends of links, for urging the first and second links to the 
greater angular relationship from a point wherein the pin is in proximity 
to the open end of the slot to the pin's second position. The latch also 
includes a lug mounted on one of the links and a stop on the other which 
come in to contact with each other when the links reach the over center 
position, preventing further rotation there between. 
Additionally, the slot includes a pair of side walls and the side wall 
adjacent to the link to which the actuator is coupled to is longer in 
length then the opposite side wall, and further includes an end at the 
opening that includes a radius. This is desirable because when the pin 
exits the open end of the slot, the over center latch assembly is not 
latched at this point. Having the one side wall with the longer length and 
radius will insure that drag forces on the opposite side wing that are 
transmitted via the link coupled directly thereto will not retard or 
prevent the links from reaching the over center position. The only effect 
will be a slight movement of the wings from a symmetrical position until 
the spring forces the latch to the over center position and wing position 
fully controlled by the actuator. Of course, a one way clutch installed 
between the second ends of the links will prevent a decrease in angular 
relationship between the links. However, by proper sizing of the spring, 
the links will be assured of reaching the over center position with or 
without the side wall extension. 
Thus upon initial release of the vehicle from the wing or bomb bay of an 
aircraft, the actuator initially causes the wings to extend. Once the over 
center position is reached, the actuator is used to simultaneously 
increase the sweep of one wing while decreasing the sweep of the other 
wing to provide roll control. Because the vehicle is released from an 
aircraft at speed, roll control by such means is immediately effective. It 
is believed that this method of roll control would not be effective at the 
initial low speeds of a normal ground takeoff, unless the vehicle were 
launched at high speeds by a booster rocket or the like. 
The novel features which are believed to be characteristic of the 
invention, both as to its organization and method of operation, together 
with further objects and advantages thereof, will be better understood 
from the following description in connection with the accompanying 
drawings in which the presently preferred embodiment of the invention is 
illustrated by way of example. It is to be expressly understood, however, 
that the drawings are for purposes of illustration and description only 
and are not intended as a definition of the limits of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIGS. 1 and 2, the vehicle, generally indicated by numeral 10, 
is depicted, for purposes of illustration, as an air launched cruise 
missile. The vehicle 10 includes a fuselage or main body 12 having a 
longitudinal axis 14A, a vertical axis 14B and a lateral axis 14C, with a 
nose 16 and tail 18, and a top mounted air intake 20. The underside 22 of 
the vehicle is in the shape of a shallow "V" having surfaces 22A and 22B 
at an acute angle 24 to the lateral axis 14C. A pair of wings 26 and 28 
are pivotally mounted to the bottom surfaces 22A and 22B. The wings 26 and 
28 are rotatable from a stored position shown in dotted lines and 
indicated by 26A and 28A to the fully extended positons shown in solid 
lines at a sweep angle 30A and 30B. Thus the angle 24 is also the dihedral 
angle of the wings 26 and 28. 
Furthermore, as will be subsequently discussed, the wing sweep angles 30A 
and 30B can be varied such that one is increased as the other is decreased 
also indicated in dotted lines and numerals 26B and 28B. The vehicle, 
includes V tails 32 and 34 that prior to launch are in stored positions 
indicated in dotted lines and numerals 32A and 34A. The wings 26 and 28 
have pivot pins 35 and 36 with pivot axis 38 and 40 supported by bearing 
assemblies 42 and 44 located on the bottom surfaces 22A and 22B. The pins 
34 and 36 have crank arms 46 and 48, respectively, attached thereto. 
Still referring to FIGS. 1 and 2, and additionally to FIGS. 3 and 4, a 
guide track 50 is mounted within the main body 12 having a closed end 52 
and an open end 54, a bottom wall 56, side walls 58 and 60, and finally 
upper lips 62 and 64 forming a slot 66 having a length 67. A pin 68 is 
slidably mounted within the slot by means of a bearing 70 attached to its 
bottom end and has a top end that extends out the top of the track 50. A 
pair of links 72 and 74 are coupled by their first ends 76 and 78 to the 
arms 46 and 48 by means of bearing assemblies 80. The second or opposite 
ends 82 and 84 are rotatably coupled to the top end of the pin 68. The 
physical positioning of the pivot axis 38 and 40 of the wings 26 and 28, 
and the track 50, cause the links 72 and 74 to be at an acute angle 88 to 
each other when the wings are in the retracted position. An actuator 90 is 
mounted within the main body 12 that includes a piston rod 92 that is 
coupled to the crank arm 48. 
An over center latch assembly 93 is incorporated that comprises a lug 94 
mounted on the link 72 in proximity to the second end 74 and stop member 
96 on the second end 84 of the link 74. The links 72 and 74 also have 
protrusions 98 and 100 that extend upward and to one side therefrom also 
in proximity to the second ends 76 and 78 and a spring 102 connected 
between the two protrusions biases the two links 72 and 74 toward each 
other. The acute angle 88 is maintained because the wings 26 and 28 are in 
the retracted position and can not move further. 
Still referring to FIGS. 1 through 4 and, additionally, to FIGS. 5 though 
8, after the vehicle 10 has been dropped from an aircraft, the actuator 90 
is signaled to retract rod 92. This causes the arm 46 to rotate clockwise 
extending wing 26. The second ends 76 and 78 of the links 72 and 74 and 
pin 68 are pulled down the slot 66 causing the angle therebetween to 
increase (FIG. 5). This causes link 74, coupled to arm 48, to 
simultaneously counter clockwise rotate wing 28 to the extended position 
in unison with the wing 26. As the pin 68 moves further down the slot 66 
the angle between the two links 72 and 74 continues to increase and, prior 
to pin exiting the slot, protrusions 98 and 100 move to the opposite side 
of the pin and the spring 102 now tends to cause the links to continue to 
angularly move apart (FIG. 6). 
Because the angular position of the links 72 and 74 are not over center at 
the point the pin 68 leaves the slot 66 (FIG. 7), aerodynamic drag on the 
wing 28 will tend to drive the links away from the over center position. 
However, proper sizing of the spring 102 will insure that the links 72 and 
74 are "pulled" to the over center position. Additionally, this drag force 
tending to retard the links 72 and 74 from reaching the over center 
position can be mitigated by providing an extension 105 to the side wall 
58 incorporating a well rounded radius 106 at its end. Thus as the wing 28 
tends to force the links toward the wing 26, the extension 105 allows the 
actuator 90 to resist this motion and allows the spring 102 to force the 
links 72 and 74 into the over center position at an angle 104, slightly 
over 180 degrees apart (FIG. 8). The lug 96 contacts the stop 96 and no 
further angular change between the links 72 and 74 can occur. 
Of course, a one way clutch 108 incorporated between the second ends 78 and 
80-(as shown in dotted lines and numeral 108 in FIG. 3) would prevent any 
reverse motion of the links. In fact, even if the links 72 and 74 did not 
reach the over center position, they would still be locked in place so 
that the actuator could still move the wings to provide roll control. 
However, once the over center position is reached, the actuator 90 can be 
used to adjust the wing sweep angle 30A and 30B by modulating the position 
of the piston rod 92. As illustrated in FIG. 9, the system is designed so 
that the arms 46 and 48 are angled toward each other at an acute angle 109 
when the wings 24 and 26 are in the extended position. This insures that 
the wing being retracted (as illustrated, wing 26) is moved a greater 
number of degrees to a sweep angle indicated by numeral 30A' than the wing 
28 being extended which is moved to a sweep angle 30B', providing more 
effective roll control. Such differential displacement of the wings 
reduces cross-coupling effects in pitch and yaw. The effect of the inward 
angled arms 46 and 48 is illustrated in FIG. 10. 
Thus it can be seen that the invention allows the use of only one actuator 
to both extend the wings and provide roll control by modulating the sweep 
angle thereof. While modulating sweep angle at low takeoff and climb 
speeds would normally not provide sufficient roll control, at the launch 
velocity of the vehicle from an aircraft at 350 miles per hour or better 
sufficient roll control can be obtained. Of course, if the vehicle were 
boosted off the ground by a solid propellant rocket or the like, 
sufficient speed would be reached before roll control was required. 
While the invention has been described with reference to a particular 
embodiment, it should be understood that the embodiment is merely 
illustrative as there are numerous variations and modifications which may 
be made by those skilled in the art. Thus, the invention is to be 
construed as being limited only by the spirit and scope of the appended 
claims. 
INDUSTRIAL APPLICABILITY 
The invention has applicability to the aircraft industry.