Abstract:
The apparatus of the invention allows flight vehicle and/or guided munition wings and control surfaces to be secured in a retracted and locked position prior to the launch by a control surface retainer. An electro-mechanical differential control system preferably releases the control surface retainer, extends the control surfaces, and servo controls the control surfaces subsequent to launch. The invention also provides a method for guiding a flight vehicle and/or guided munition by releasing the flight vehicle&#39;s and/or guided munition&#39;s control surface from a control surface retainer, extending the flight vehicle&#39;s and/or guided munition&#39;s wing/control surface assembly using a wing/control surface actuation system, and controlling the flight vehicle&#39;s and/or guided munition&#39;s control surfaces using a wing/control surface actuation system.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to extendable and controllable wings and control surfaces on a flight vehicle and/or a guided munition. More particularly this invention relates to a device and method for pre-launch retainment and post-launch deployment of wings and control surfaces on a flight vehicle and/or a guided munition, as well as post-launch control of the flight vehicle&#39;s and/or the guided munition&#39;s control surfaces. 
     A significant disadvantage of conventional flight vehicles and guided munitions that deploy wings and control surfaces after launch is that they employ complicated or dangerous deployment techniques. Specifically, these techniques include hydraulics, pyrotechnics, compressed springs, and pneumatics generated from a pyrotechnic device. 
     One drawback associated with the use of pyrotechnics is that pyrotechnics have a limited shelf life and must be periodically replaced. 
     Another drawback with the use of pyrotechnics is that one is precluded from repeatedly testing the device due to the fact that pyrotechnics are limited to a one time use. 
     Yet another drawback of conventional flight vehicles and guided munitions is that control over the deployment of the wings and control surfaces is accomplished separately from the control over the control surfaces during flight. This involves more parts. Additional parts increase the risk of failure due to part malfunction and also increases the overall weight of the flight vehicle and/or guided munition. 
     Yet still another drawback of conventional flight vehicles and guided munitions is that flight failures have occurred due to non-uniform deployment of wings and control surfaces. 
     It therefore would be desirable to provide a flight vehicle and/or a guided munition wing/control surface deployment device that reduces the danger to personnel handling the device. 
     It would also be desirable to provide a flight vehicle and/or a guided munition wing/control surface deployment device that does not have a limited shelf life. 
     It would further be desirable to provide a flight vehicle and/or a guided munition wing/control surface deployment device that may be repeatedly tested without a single use limitation. 
     It would still further be desirable to provide a device that controls both the deployment of the wings and control surfaces and controls the control surfaces during flight. 
     It would yet still further be desirable to provide a system that ensures uniform deployment of a wings and control surfaces for a flight vehicle and/or a guided munition. 
     SUMMARY OF THE INVENTION 
     Therefore, it is an object of this invention to provide a flight vehicle and/or a guided munition wing/control surface deployment device that reduces the danger to personnel handling the device. 
     It is also an object of this invention to provide a flight vehicle and/or a guided munition wing/control surface deployment device that does not have a limited shelf life. 
     It is a further object of this invention to provide a flight vehicle and/or a guided munition wing/control surface deployment device that may be repeatedly tested without a single use limitation. 
     It is still further an object of this invention to provide a device that controls the deployment of the wings and control surfaces and also controls the control surfaces during flight. 
     It is a yet still further an object of this invention to provide a system that ensures uniform deployment of wings and control surfaces for a flight vehicle and/or a guided munition. 
     In accordance with this invention an apparatus including a control surface retainer system, a wing/control surface actuation system, and may include a uniform wing/control surface deployment system is provided. The control surface retainer system prevents the wings and/or control surfaces from extending prior to the launch of a flight vehicle. The wing/control surface actuation system releases the control surface retainer, extends the wing/control surface assembly locking the assembly into position at a predetermined angle, and servo controls the control surfaces to direct the flight vehicle and/or the guided munition to a target. The uniform wing/control surface deployment works in conjunction with the wing/control surface actuation system to ensure uniform deployment of the wing/control surface assemblies. 
     Another aspect of the invention includes a method for releasing a wing/control surface assembly from a retracted position, extending a wing/control surface assembly to a predetermined angle using a wing/control surface actuation system, and controlling a control surface to guide the flight vehicle and/or the guided munition to a target using the wing/control surface actuation system. 
     A further aspect of this invention may include a method for releasing a wing/control surface assembly from a retracted position, extending uniformly a plurality of wing/control surface assemblies to a predetermined angle using a plurality of wing/control surface actuation systems, and controlling a control surface to guide the flight vehicle and/or the guided munition to a target using the wing/control surface actuation system. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and other objects and advantages of the invention will be apparent upon consideration of the following detailed description, taken in conjunction with the accompanying drawings, in which like reference characters refer to like parts throughout: 
     FIG. 1 is a top view of a schematic diagram according to the invention where the flight vehicle and/or the guided munition control surface is in a stowed and locked position. 
     FIG. 2 is a side view of a schematic diagram according to the invention where the flight vehicle and/or the guided munition control surface is in a stowed and locked position. 
     FIG. 3 is an end view of a schematic diagram according to the invention where the flight vehicle and/or the guided munition control surface is in a stowed and locked position. 
     FIG. 4 is a side view of a schematic diagram according to the invention where the flight vehicle and/or the guided munition control surface is fully deployed. 
     FIG. 5 is a front isometric view of a schematic diagram according to the invention where the flight vehicle and/or the guided munition control surface is fully deployed. 
     FIG. 6 is a rear isometric view of a schematic diagram according to the invention where the flight vehicle and/or the guided munition control surface is fully deployed. 
     FIG. 7 is a perspective diagram according to the invention where the flight vehicle and/or the guided munition control surface assemblies are uniformly deployed. 
     FIG. 8 is a flow chart according to the invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     An apparatus according to the invention includes a control surface retainer system, a wing/control surface actuation system, and may include a uniform wing/control surface deployment system. The control surface retainer system preferably retains a wing/control surface assembly until launch. Then, after the launch, the wing/control surface actuation system preferably unlocks and deploys a wing/control surface assembly. The uniform wing/control surface deployment system controls the uniform deployment of a plurality of wing/control surface assemblies. Then, following deployment, the system moves the control surface with respect to the wing as part of a control surface servo control system. 
     The control surface retainer system locks the flight vehicle&#39;s and/or the guided munition&#39;s wing/control surface assembly in a retracted position prior to the launch of the flight vehicle and/or the guided munition. Subsequent to launch the wing/control surface actuation system uses a differential with one input and two outputs. The two differential outputs are as follows: 1) the output may cause the control surface to rotate about a rotation axis and 2) the output may cause the wing/control surface assembly to extend from the flight vehicle and/or the guided munition. Additionally, subsequent to launch, if a plurality of wing/control surface actuation systems cause a plurality of wing/control surface assemblies to be deployed, the uniform deployment system ensures that the wing/control surface assemblies are deployed uniformly with respect to one another. 
     In a preferred embodiment of the invention, this differential is implemented using two bevel gears. A first bevel gear provides a rotational force as an input to the wing/control surface actuation system. The second bevel gear, which is preferably meshed to, and positioned at a 90° angle to, the first bevel gear, has one of two possible responses, each of which correspond to one of the differential outputs listed above, to the input rotation provided by the first bevel gear. 
     One possible response is to cause the control surface to rotate about a substantially central longitudinal rotational axis of the control surface. The other possible response is to move in a rotational direction about a central longitudinal rotational axis of the first bevel gear and, thereby, to extend outward from the flight vehicle and/or guided munition. In general, the output is determined only when one of the possible outputs is restricted. Restriction of the outputs may be implemented according to design choices. 
     The differential system according to the invention uses a first output to unlock the flight vehicle&#39;s and/or guided munition&#39;s control surface retainer and utilizes the second output to extend the flight vehicle&#39;s and/or guided munition&#39;s wing/control surface assembly to a predetermined fixed position, as will be explained in greater detail below. Once the wing/control surface assembly is deployed and positioned in the fixed position, the second output is restricted. Thereafter, the differential system returns to using the first output. At this point, the first output is no longer required to unlock the wing/control surface assembly. Rather, the first output can be utilized to act as a servo control over the flight vehicle&#39;s and/or guided munition&#39;s control surface to guide the flight vehicle and/or guided munition. 
     Additionally, if a plurality of wing/control surface actuation systems cause a plurality of wing/control surface assemblies to be deployed, these assemblies may be uniformly deployed using a uniform wing/control surface deployment system. 
     One embodiment of this uniform wing/control surface deployment system may include a mechanical link (e.g., arc bevel gears, spur gears, rubber tired wheel, and chain, etc.) between a plurality of wing/control surface assemblies. This mechanical link may include a plurality of arc bevel gears. Each bevel gear is fixed to a wing/control surface assembly and may be positioned at an angle greater than 0° and less than or equal to 180° with respect to one another. The exact angle between these gears will be determined by the number of wing/control surface assemblies actually deployed. 
     As each wing/control surface assembly deploys, these bevel gears rotate in the direction of the wing/control surface assembly deployment. As these gears rotate, they mesh with each other, thereby preventing each wing/control surface assembly from deploying asymmetrically. By controlling the rate at which each wing/control surface assembly may deploy, these gears cause the individual rotational forces to be added together, creating a total rotational force. 
     The total force generated is distributed equally among each of the wing/control surface assemblies, such that these assemblies are substantially uniformly deployed. 
     FIGS. 1-3 show a top, side, and end view of a schematic diagram of one embodiment of an apparatus  100  according to the invention. In these views, flight vehicle/guided munition wing/control surface assembly  104  is stowed and locked. The control surface retainer system includes stow notch  102  mounted in flight vehicle/guided munition frame  106 . The wing/control surface assembly preferably includes a stow tab  108  that corresponds to stow notch  102 . In this particular embodiment, a rotation of control surface  200  releases stow tab  108  from stow notch  102 , as will be explained. 
     Stow notch  102  is preferably fixed to frame  106 . Control surface  200  is preferably hinge-mounted by hinge  204  to wing  202 , and is rotatable about control surface rotation axis  300 . Additionally, stow tab  108  is integrated into control surface  200 . These FIGS. also show motor  110 , worm shaft  112 , worm wheel  114 , first bevel gear  116 , second bevel gear  118  and position reporting device  120 . Preferably, position reporting device  120  is located directly on fin shaft  140 . Position reporting device may also be located on the rear of motor  110 . 
     FIGS. 4-6 show additional views of apparatus  100 . In these views, wing/control surface assembly  104  is extended and deployed. These views more clearly illustrate the wing/control surface actuation system which provides the rotational force required by apparatus  100 . 
     The wing/control surface actuation system includes motor  110  that rotates worm shaft  112 . The rotation of worm shaft  112  causes worm  114  to rotate. Worm  114 , in turn, drives worm wheel  600 . Worm wheel  600  drives first bevel gear  116 . First bevel gear  116  rotates with worm wheel  600  and drives second bevel gear  118 . Second bevel gear  118  is preferably attached to wing/control surface assembly  104  by shaft  602 . The two different responses of second bevel gear  118  to the rotation of first bevel gear  116  will be explained below. 
     Apparatus  100  operates as follows. When the flight vehicle and/or guided munition is launched, the locked and stowed position of the control surface is reported by position reporting device  120  to a suitable control mechanism  150 —e.g., a microprocessor. The control commands motor  110  to rotate worm shaft  112 . Worm shaft  112  rotates worm  114  in the direction to unblock the wing. If worm  114  is a right hand worm, the direction will be as shown by the arrow in FIG.  1 . Worm  114  in turn drives worm wheel  600 . Worm wheel  600  then drives first bevel gear  116 , which meshes with second bevel gear  118 . 
     The rotation of second bevel gear  118 , which is attached to wing/control surface assembly  104  by shaft  602 , rotates the stow tab  108  out of stow notch  102 . This output of the differential is selected because the alternative option of the differential output—i.e., to lift second bevel gear  118  and rotate it [together with wing/control surface apparatus  104 ] about first bevel gear axis  130  in order to accommodate the rotation of first bevel gear  116  is not available. This option is not available because the leading edge of control surface  200  is restrained from moving in a direction having a component of motion perpendicular to axis  300  by stow notch  102 . Thus, the first response from the differential to the rotation of first bevel gear  116  is to rotate control surface  200  about axis  300 . 
     Preferably substantially simultaneously to stow tab  108  clearing stow notch  102 , the trailing edge of control surface  200  strikes guide block  302 , preventing further rotation of control surface  200  about axis  300 . 
     Because the first output response—i.e., to rotate control surface  200  about axis  300 —is not available, then the second output response—i.e., to cause second bevel gear  118  to rotate about axis  130 , and, thereby, to deploy or extend the wing/control surface assembly—is carried out. This occurs when the trailing edge of control surface  200  is stopped from rotating by guide block  302 . It is important to note that if both of the output options would have been available—i.e., non-restricted—the result of the input would have been substantially indeterminate. 
     When wing/control surface assembly  104  moves to a predetermined angle, spring-loaded pin  500  locks wing/control surface assembly  104  into place via pin hole  504 . Once wing/control surface assembly  104  is locked into position, extension of the wing/control surface assembly from the flight vehicle and/or guided munition is restricted. Thus, the second output of the differential is no longer available. 
     But, at this point, the trailing edge of control surface  200  has cleared guide block  302  and can move freely with respect to guide block  302  and wing  202 . Thus, the output of the differential returns to the first output response which preferably causes rotation of control surface  200  about control surface axis  300 . This rotation can be utilized by control mechanism  150  to direct motor  110  to control control surface  200  such as to guide the flight vehicle and/or guided munition. One purpose of controlling control surface  200  is to guide the flight vehicle and/or guided munition. This control may be implemented by utilizing control surface position information from position reporting device  120  and target information provided by an external source. 
     FIG. 7 shows a perspective diagram of one embodiment according to the invention. This view illustrates one embodiment of the uniform wing/control surface deployment system. The uniform wing/control surface deployment system, in this illustrative example, includes arc bevel gears  700 ,  710 ,  720 , and  730 . Furthermore, in this illustration, wing/control surface assemblies  705 ,  715 ,  725 , and  735  are also shown. Arc bevel gear  700  is preferably fixed to  705 , arc bevel gear  710  is preferably fixed to  715 , arc bevel gear  720  is preferably fixed to  725 , arc bevel gear  730  is preferably fixed to  735 . In this particular embodiment arc bevel gears  700 ,  710 ,  720 , and  730  are at 90° angles with respect to one another. 
     As wing/control surface assemblies  705 ,  715 ,  725 , and  735  deploy, arc bevel gear  700 ,  710 ,  720 , and  730  mesh at a point tangent to one another&#39;s adjacent gear, e.g. gear  700  meshes to gear  710  and  730  at tangent points  770  and  780 . Thus, wing/control surface assemblies  705 ,  715 ,  725 , and  735  are forced to deploy uniformly. 
     FIG. 8 shows a flow chart  800  of the operation of an apparatus according to the invention. Box  810  shows the pre-launch restraining of the wing/control surface assembly. Box  820  shows the launch. Box  830  shows the wing/control surface actuation system unlocking the wing/control surface assembly from the locked position. Box  840  shows the preferably post-launch extension of the wing/control surface assembly by the wing/control surface actuation system. Box  850  shows the wing/control surface actuation system locking the wing/control surface assembly in its proper position. Box  860  shows the wing/control surface actuation system servo controlling the control surface in order to guide the flight vehicle and/or guided munition. 
     Thus, an extendable and controllable flight vehicle and/or guided munition wing/control surface actuation system is provided. Persons skilled in the art will appreciate that the present invention can be practiced by other than the described embodiments, which are presented for purposes of illustration rather than of limitation, and the present invention is limited only by the claims which follow.