Abstract:
The openings in the fabric ribs of a deployable wing made from fabric sail material is automatically closed by use of a zipper mounted adjacent each of the openings that is actuated by movement of the cross spars of the deployable wing which serves to prevent the airfoil surface to the wing to bulge and cause a drag to the deployable wing when in flight.

Description:
TECHNICAL FIELD 
     This invention relates to a glider and particularly of the deployable wing type and the mechanism for closing the access cut-out of the rib to allow the cross bar to translate so as to avoid protrusions in the airfoil of the sail of the wing when deployed. 
     BACKGROUND OF THE INVENTION 
     This invention constitutes an improvement over U.S. Pat. Nos. 5,474,257 and 5,878,979 granted on Dec. 12, 1995, to Fisher et al, entitled Deployable Wing and Mar. 9, 1999, to Fisher et al, entitled Method and Apparatus for Landing a Wing, respectively. The patentees of these two patents are the same joint inventors of the invention covered in the above-captioned patent application and this application and these two patents are commonly assigned and both patents are incorporated herein by reference. These patents relate to deployable wings that are designed to carry a payload remote from the an air dropoff and for details of its construction reference should be made thereto. Suffice it to say that the common subject matter relates to deployable wing that comprises internal structure that is folded in a compact package that is airlifted by aircraft to an approximate destination and thereafter released and through the advent of sequentially operated parachutes is caused to deploy into a wing that is formed from a lower and upper delta shaped sail that is bounded at the edges to form an airfoil shaped enclosure. An opening at the forward center of the wing admits air to internally to fill the pocket defined by the lower and upper sails and expand the airfoil of the glider. The internal structure includes divergent leading edge spars attached to a central keel and a pair of diametrically opposed cross spars that when stored are folded into a relatively in-line or parallel position and when deployed the leading edge spars and cross spars extend perpendicular to the keel to form essentially a delta wing. Typically, after the glider is dropped from the aircraft parachutes are deployed and causes a slider to translate which, in turn, causes the cross spars that are pivotally attached to a sliding mechanism and each of the leading edge spars to translate and move angularly relative to the keel. The ram air then causes the wing to inflate, and once the glider is fully deployed these parachutes are disengaged from the wing and the glider begins its forward flight to its guided destination. The mechanism for performing these functions are detailed in U.S. Pat. No. 5,474,257 and for further details reference should be made thereto. 
     An internal heavier fabric is sewn to the lower sail and forms a portion thereof and extends to the upper sail and is sewn to define a protective pocket for the leading edge spars. A plurality of ribs formed from fabric is sewn to the upper sail and lower sail and extends from the forward to the aft end of the internal fabric. These ribs are equally spaced and extend across the cross spar. Obviously, a slot is formed in the ribs to allow the transition of the cross spar from the stored position to the deployed position, The length of the slots is sufficient to allow the cross spars to move the distance required to deploy the wing. The slot is say, approximately 12 inches and in the heretofore designs the slot remained unaltered and, hence, opened. Although the opened slot is internal, the effect of this opening causes bulges in the airfoil on the upper and lower sails adjacent to these openings when the wing is extended due to the external and internal air pressure acting on the wing. These bulges or protrusion in the sail are a source of drag and adversely affect the efficiency of the wing. 
     The purpose of the present invention is to solve this bulging problem and hence, alleviate a condition on the airfoil that adversely impacts the flight thereof. We have found that by employing a zipper and the mechanism for causing the zipper to close and eliminate the slot the problem of the opened slot is alleviated or at least minimized. 
     SUMMARY OF THE INVENTION 
     An object of this invention is to provide an improved deployable wing by eliminating the slot that permits the cross spar to translate and deploy the leading edges and wing of the deployable wing. 
     A feature of this invention is to provide a plurality of closure material and zippers that are formed in the rib portion of the sail fabric at locations where the cross bar slides under the otherwise cutout of the ribs in the location where the bulging in the deployed airfoil occurs and mechanism to actuate the zipper to enclose the space that permits the passing of the cross bar when being deployed. 
     The foregoing and other features of the present invention will become more apparent from the following description and accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view, partly broken away, of the prior art deployable wing depicting the effect of the bulging when the wing is airborne and modified to incorporate this invention; 
     FIG. 2 is a diagrammatic view in schematic illustrating the details of this invention; and 
     FIG. 3 is a diagrammatic view in schematic illustrating the zippered panel of FIG. 2 in the non-deployed position. 
     FIG. 4 is a diagrammatic view in schematic of the embodiment depicted in FIG  1 . where the zippered panel is in the deployed position. 
     These figures merely serve to further clarify and illustrate the present invention and are not intended to limit the scope thereof. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now in specific detail to the drawings, with like reference numerals identifying similar or identical elements, FIG. 1 illustrates a perspective view, partially broken away, of one embodiment of the deployable wing  10  of the present application. As illustrated in FIG. 1, wing  10  includes a fabric sail  12  defining a leading edge  14  and a trailing edge  16 . Fabric sail  12  preferably includes an upper section  12   a  substantially joined along its perimeter to a lower section (not shown) and a plurality of fabric ribs (not shown) connected to the upper and lower sections of the fabric sail. Joining the upper and lower sections forms an envelope which can be filled with air through a ram air intake  20  preferably located at the foremost point of the wing. In the present embodiment fabric sail  12  further includes an integral cover sheet  13  comprising a first section  13   a  and a second section  13   b , each of which is disposed along the leading edge of wing  10  as shown in FIG.  1 . First and second sections  13   a,    13   b  each further include complimentary zipper members  15   a,    15   b  which matingly engage in a conventional manner to contain fabric sail  12  within the integral cover as described hereinbelow. In the present embodiment cover  13  is preferably made of DACRON fabric while zipper members  15   a,    15   b  are of a sufficiently high strength and durability to operate under deployment conditions, although other materials may be utilized depending upon the design configurations of the wing. 
     With continued reference to FIG. 1, wing  10  further includes an internal structure comprising two leading edge spars (not shown), two cross-spars  22   a,    22   b,  a keel  24 , a kingpost  26  and a control device, such as elevon struts  28   a,    28   b.  The leading edge spars are pivotally attached at one end between faceplates  17   a  and  17   b  to form foremost point  21 . Pivotally connected the leading edge spars at a second end thereof are elevon struts  28   a,    28   b.  Keel  24  is mounted at a first end between faceplates  17   a  and  17   b , and is mounted at an opposite end between rear plate members  27   a  and  27   b  and is disposed between the leading edge spars. Cross spars  22   a,    22   b  each include an outboard end which is pivotally attached to a corresponding leading edge spar and further include inboard ends, opposite the outboard ends, which are pivotally attached to keel  24 , preferably via a common slider  80 . Kingpost  26  is also preferably mounted to keel  24  via the common slider. When erected, kingpost  26  extends substantially perpendicular to keel  24 , through an opening in fabric sail  12 , to provide an upper attachment point for wires  31   a,    31   b  which support the wing on landing and when the wing experiences negative loads or inverted flight. In the present embodiment kingpost  26  is pivotally attached to slider  32  such that linear movement of the slider in the direction of arrow “A” causes kingpost  26  to erect through the fabric sail, substantially perpendicular to the keel. 
     The leading edge spars and cross spars are preferably pivotally mounted such that in a closed or pre-deployed position the leading edge spars and cross spars  22   a,    22   b  rest substantially parallel to keel  24 . In the closed position the common slider is preferably disposed adjacent the foremost point and kingpost  26  is preferably disposed adjacent and substantially parallel to keel  24 , beneath fabric sail  12 . In the closed position complimentary zipper members  15   a,    15   b  are matingly engaged in a conventional manner to contain fabric sail  12  within the integral cover. Preferably, the leading edge spars, cross spars, keel, elevon struts, kingpost and wing tips  29   a,    29   b  are all substantially disposed within fabric sail  12  in the closed position. 
     The length of each leading edge spar is dependent upon the desired size of wing  10 , which is only limited by practical considerations: size once folded, desired cruise speed, weight of the payload, etc. Once opened, or deployed, the leading edge spars form an angle therebetween. The size of the angle depends upon aerodynamic considerations including aspect ratio, yaw stability, and deployment simplicity, among others. Typically, the angle ranges from about 90° to about 150° with about 105° to about 110° preferred due to simplicity of the deployment mechanism geometry. Angles greater than about 150° result in more complex, and therefore less desirable, mechanical/structural geometry and decreasing yaw stability, while angles less than about 90∠ result in decreasing glide ratio. Yaw stability is where wing sweep allows the wing to tend to maintain its flight directly into the wind, commonly known as maintaining the yaw heading. As the wing yaws, the windward wing tends to drag more than the leeward wing, thereby correcting for the yaw. 
     Cross spars  22   a,    22   b  provide structural integrity to the wing  10  by providing strength to the leading edge spars to ensure that in the deployed position the leading spars remain in the open position with the appropriate angle therebetween. The distance between the attachment point of the outboard ends to their respective leading edge spars and the inboard ends to the keel determine the length of cross spars  22   a,    22   b.    
     With continued reference to FIG. 1, keel  24  similarly provides structural integrity to wing  10  by ensuing that the wing  10  opens to and maintains its full length from the leading edge  14  to the trailing edge  16 , commonly known as the wing&#39;s chordwise length. The length of the keel  24  is substantially equivalent to the chordwise length of the wing at the root (very center line) which, as with the leading edge spars&#39; length, is determined on a practical basis with aeronautical considerations effecting the ultimate size. Keel  24  also connects payload  50  to wing  10  via mounting member  42   
     The present embodiment also includes elevon struts  28   a,    28   b  which are each connected to a motor or fluid actuator  30   a,    30   b,  the actuators being located externally of fabric sail  12  and mounted to the leading edge spars. The motor or actuator is conventional in design and operates to deflect or rotate each elevon struts  28   a,    28   b  independently, out of the plane of the sail, thereby controlling the flight of the wing. By rotating the elevon struts, wing tips  29   a,    29   b  are twisted up or down relative to the leading edge. This helical twisting of the sail results in an aerodynamic force sufficient to pitch or roll the wing. Rotating or deflecting the elevon struts in unison generates an aerodynamic force substantially behind the pressure center of the wing which is located at the point about 55% down the keel from the foremost point  16 , thereby forming a moment force about the pressure center which is used for pitch control of the wing. By rotating or deflecting the elevon struts  28   a,    28   b  singularly or in opposite directions, aerodynamic forces at the wing tips  29   a  and  29   b  can be controlled in magnitude and direction, up or down. For example, if the elevon strut  28   a  is rotated up while elevon strut  28   b  is rotated down, a downward force is generated on tip  29   a  and an upward force on tip  29   b,  resulting in a roll or turn in the direction of strut  28   a.    
     These elevon struts  28   a,    28   b , or other control devices, can be operated with any conventional motor capable of generating sufficient torque to overcome the aerodynamic forces at a speed sufficient for control response. Factors important in determining the required torque include wing area, wing loading, aspect ratio, and elevon strut length, among others. A wing having a 30 foot wing span, for example, with a sail area of about 190 ft 2  and a 700 lb load requires about 40 to about 80 ft lb torque while a 15 ft wing span wing with an area of 45 ft 2  and a 90 lb load needs about 15 to about 25 ft lb torque for control. 
     In the present embodiment the length of kingpost  26  is approximately 4 ft. which, as with the keel&#39;s and leading edge spars&#39; length, is determined on a practical basis with aeronautical considerations effecting the ultimate size. In addition to providing an upper attachment point for wires  31   a, b  as described above, kingpost  26  also provides support for strap  32  which is attached at one end between front plate members  33   a,    33   b,  extends over the kingpost and is attached at an opposite end between rear plate members  27   a,    27   b.  Strap  32  is of a sufficient length such that when the strap extends over the kingpost and is strapped between plate members  33   a,    33   b  and  27   a,    27   b,  there is enough slack present in the strap to allow the strap to be pulled free of the kingpost when parachutes  44  deploy. 
     Attached to strap  32  at approximately its midpoint, in the present embodiment, is parachute attachment line  34 . The point at which line  34  attaches to strap  32  is the point at which the wing  10  with cargo pod, or payload  50  will hang substantially horizontal beneath the parachutes without excessive rotation or pitching. Likewise, the length of strap  32  is length at which the payload will hang substantially horizontal beneath the parachutes. Attachment of line  34  to strap  32  is achieved in the present embodiment through loops which are sewn onto strap  32  and line  34  and which are connected by a clevis fitting, though any conventional method of attachment which will allow for parachute deployment may be utilized. Attachment line  34  is joined at an opposite end to parachute deployment system  40  and includes a second line  34   a  which branches from the attachment line  34  and attaches to a secondary release mechanism disposed within mounting block  38 . Mounting block  38  is connected to wing mounting member  36  which is mounted to both keel  24  and payload pod  0 , the mounting member thereby attaching the payload to the wing. The secondary release mechanism  39  provides controlled release of a parachute deployment system  40  which is described in greater detail below. The present embodiment may include a platform  94  mounted to the underside of cargo pod  50  which aids in the mounting of the wing in the aircraft and in the landing thereof. An antenna  49  may also be carried on the fore end of the wing  10  for the radio control navigation. 
     The cutout  13  in rib  11  adjacent the cross tube spar  25   a  serves to allow the cross tube spar to move axially rearward when the wing is being deployed. As mentioned above, in this area of the airfoil the forces internally of the wing caused the airfoil to bulge creating a drag on the flight of the wing. The invention obviates this problem by adding material  15  to this area of the cutout that complements the cut out portion. A male toothed portion  21  and female toothed portion  23  of the zipper  19  serve to close this cutout when the wing is deployed. This is accomplished by tying the zipper handle  31  of the zipper  19  to the cross tube spar  25   a  with a cord or string so that when the cross tube spar  25   a  is deployed the zipper will close in a conventional manner. By closing the cutout, it was observed that the bulges in the airfoil of the wing were eliminated when the wing was deployed and airborne. Obviously, each of the cutouts for each of the ribs accommodating the motion of the cross tube spar  25   a  will include a similar zippered fabric insert. 
     The operation of the zippered fabric insert is best demonstrated in FIG. 3 and 4 diagrammatically showing the spar moved from one position to the other and the added material with the zippered edge being activated by the movement of the cross tube spar  25   a . As noted in FIG. 4 when the wing is completely deployed the cord  33  attached to the cross tube spar  25   a  and the zipper closure has caused the zipper to substantially close the cutout portion of rib  11  and essentially tie the top sail  12   a  to the bottom sail  12   b  through the rib  11 . 
     Although this invention has been shown and described with respect to detailed embodiments thereof, it will be appreciated and understood by those skilled in the art that various changes in form and detail thereof may be made without departing from the spirit and scope of the claimed invention.