Abstract:
A catapult for launching an aircraft is disclosed including a rail assembly having first and second ends. A support structure is provided for supporting the rail assembly above the ground at various upward angles. A container having an open end is releasably mounted on the first end of the rail assembly, the container for mounting the aircraft therein with a portion of the front end of the aircraft extending out of the open end. A device is provided for extracting the aircraft from the container and moving it from the first end to the second end of the rail assembly and release it when reaching the second end.

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The invention relates to the field of aircraft catapults and, in particular, to a portable catapult for micro or miniature aircraft. 
     Aircraft catapults are old in the art. In fact, a weight-activated catapult was used to launch the Wright brothers&#39; first aircraft. Everything from hydraulic to steam has been used to launch aircraft from aircraft carriers. However, most practical catapults are designed for use with aircraft having landing gear. If the aircraft has no landing gear attaching the catapult to the aircraft can prove difficult. However, if operated in areas where no landing field is available, such as in rugged mountain terrain, the landing gear would be useless for recovery and a parachute recovery system must used. 
     With small model aircraft, an inexpensive approach is to toss the aircraft into the air by hand. Another approach is a simple rod with a rubber band that is attached to a notch on the fuselage of the aircraft. However, these “catapults” have been used primarily with flat balsa wood “cutouts” type models weighing only a few ounces. With anything larger, such methods are unlikely to work because of handling difficulties. In addition, any catapult should allow for hand free operation so the operator&#39;s hands are free to operate a radio control console. Furthermore, any such catapult should be light in weight and collapsible for storage and carrying purposes. 
     Thus, it is a primary object of the invention to provide a catapult system for an aircraft that is simple to set up. 
     It is another primary object of the invention to provide a catapult system for an aircraft such that the aircraft remains protected until actual launch. 
     It is a further object of the invention to provide a catapult system for an aircraft that allows hands free operation so that the operator can use both hands to operate a remote control. 
     It is a still further object of the invention to provide a catapult system for an aircraft that is inexpensive to manufacture. 
     It is still another object of the invention to provide a catapult system for an aircraft that can be stored in a compact package. 
     SUMMARY OF THE INVENTION 
     The invention is an aircraft catapult assembly. In detail, the assembly includes a rail having first and second ends with a support system for supporting the rail above the ground at various upward angles. Preferably, this support system includes a pair of telescoping support members at the second end and a fitting at the first end having a stake for driving in the ground for locking the rail in place. An aircraft container having an open end is releasably mounted on the first end of the rail such that the leading edges of the wings of the aircraft extend out of the container. 
     An aircraft towing assembly is movably mounted on the rail, which is movable from the first end to the second end. An attachment device is used to releasably connect the wings of the aircraft to the aircraft towing assembly. Thus as the aircraft towing assembly is moved from the first to the second end of the rail, the aircraft is towed there along and released when the towing assembly reaches the second end. A stop member at the second end of the rail prevents the towing assembly from moving further. Preferably, this attachment device includes first and second wire loops mounted on the leading edge of the left and right wings of the aircraft and the towing assembly includes first and second hooks mounted thereon for releasably engaging these first and second wire loops. 
     A locking device is provided for releasably holding the towing assembly at the first end of the rail. The locking device includes a loop of rope having first and second ends, with the first end attached to the towing assembly. A cable operated release assembly is coupled to the fitting at the first end of the rail. This cable operated release assembly includes a pin having a first position in engagement with the second end of the loop of rope and a second position out of engagement therewith. A foot petal operated cable is coupled to the pin for moving the pin out of engagement with the loop of rope. 
     A pair of bungee cords are attached to the towing assembly and extend to the second end of the rail and about a pulley mounted at this point and extends partially back to the first end. A cord is attached to the bungee cord having a plurality of spaced apart knots thereon. The fitting at the first end of the rail includes a notch wherein the cord can be inserted and one of the knots will prevent the cord from moving. Thus, the cord can be used to apply a tension load to the bungee cords and the cord can be attached to the fitting by placing the cord in the notch. 
     Preferably, the rail is composed of a plurality of hollow interlocking segments and an elastic cord is mounted within the interlocking segments and attached to the first and second ends thereof for releasably holding the segments in the interlocking position. In addition, the telescoping supports on the second end of the rail are pivotally mounted thereto and thus they can be folded along the rail. In addition, the cable and foot petal can be disconnected from the fitting and the container can be removed. This allows the rail assembly to be folded into a compact shape for storage. 
     To “arm” the catapult, the cord is pulled tight and locked in place by “hooking” one of the knots into the notch in the fitting. The support members at the second end of the rail are extended and the stake is driven into the ground. Thereafter, the carrying case with the aircraft installed therein is attached to the fitting at the first end of the rail. The wire loops are attached to the hooks on the towing assembly. At this point the aircraft is ready to launch. The operator presses on the foot petal causing the cable to retract, releasing the loop of rope. The towing assembly is then pulled down the rail. 
     As this occurs, the aircraft is pulled out of the carrying case and transported down the rail. When the towing assembly gets to the end of the rail at the second end and contacts the stop, the hooks automatically separate from the wire loops and the aircraft is catapulted into the air. The operator can thereafter start the motor and guide the aircraft by means of a radio control system. Of course the motor could be started prior to launch. 
     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. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side view of the catapult. 
     FIG. 2 is a partial perspective view of the rear end of the catapult. 
     FIG. 3 is a partial cross-section view of the rear end of the catapult show in FIG.  2 . 
     FIG. 4 is a partial top view of the catapult shown in FIG. 1 illustrating the front end of the catapult. 
     FIG. 5 is a side view of the catapult shown in FIG. 1 illustrating the front end of the catapult. 
     FIG. 6 is a partial perspective view of the front end of the catapult shown in FIG.  1 . 
     FIG. 7 is a partial top view of the catapult shown in FIG. 1 illustrating the aircraft and carrying case therefore mounted on the aircraft-towing member. 
     FIG. 8 is a side view of FIG.  6 . 
     FIG. 9 is a cross-section view of FIG. 8 taken along the line  8 — 8 . 
     FIG. 10 is a front view of the foot petal assembly used to release the aircraft. 
     FIG. 11 is a side view of the foot petal assembly shown in FIG. 10 partially broken away to show the interior thereof. 
     FIG. 12 is a top view of the foot petal assembly shown in FIG. 10 partially broke away to show the interior thereof. 
     FIG. 13 is a view of the catapult partially disassembled. 
     FIG. 14 is a view of the catapult in the stored condition. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIGS. 1-4, the catapult, generally designated by numeral  20  includes a rail assembly  22 , having a longitudinal axis  23 , composed of four interlocking sections,  24 ,  26 ,  28  and  30 . These four sections  24 - 30  are all hollow and square in cross-section. The section  24  includes a first end  32  and a second end  34  having a fitting  36  inserted therein; the details of this fitting  36  will be subsequently discussed. The section  26  includes a first end  38  and a second end  40  having a reduced cross-section that mates with the interior of the end  32  of the first section  24 . The intermediate section  28  also includes a first end  42  and a second reduced cross-section second end  44  that mates with the interior of the end  38  of section  26 . Finally, the section  30  includes a second end  45  having a member  46  installed therein, which will be subsequently discussed. The section  30  also includes a reduced cross-section end  48  that mates with the interior of the end  42  of the section  28 . A bungee cord  50  is mounted within the rail assembly  22  and is attached to the fittings  36  and  46  by means of hook  52 A and  52 B, respectively. Thus the sections  24 - 30  are held together under a “spring” load but can be separated and folded for storage purposes, which will be subsequently discussed. 
     An aircraft towing member  60  is slidably mounted to the rail assembly  22  by means of an integral bushing  62 . The towing member  60  includes a plate  64  mounted on top of the bushing ± 62  having a pair of thin vertical plates  66 A and  66 B spaced symmetrically on each side of the longitudinal axis  23  at a distance  68  from each other. The plat  64  can be bonded to the bushing  62  or joined by fasteners (not shown). Hooks  70 A and  70 B are mounted on top of the vertical plates  66 A and  66 B, respectively. The front end  72  of the bushing  62  includes stop members  74 A and  74 B incorporating resilient bumpers  76 . The top of the rear end  78  of the bushing  62  includes a flange  8 e having a hole  83 , which incorporates a loop of rope  84  therethrough. A pair of arms  85 A and  85 B extend from the front end  72  of the bushing  62  having a pin  86  mounted therebetween. 
     The member  46  mounted to the end  45  of the section  30  of the rail assembly  22  includes a plug portion  88  extending within the section  30  and bonded thereto and has a first end  90  having a partially threaded hole  92  in which the hook  52 B is threadably engaged therewith. The plug portion  88  includes a notch  94 . The end  96  of the plug portion  88  includes a hole  98 . A thumbscrew  100  is installed in a second threaded hole  102  that intersects the hole  98 . A vertical plate  104  extends upward from the side of the end  96  of the plug portion  88  and is connected to a horizontal plate  106  that extends over the plug portion forward of the notch  94 . A half of a loop and hook type fastener  107  is mounted to the top of the horizontal plate  106 . A vertical member  110  extends downward from the plug member  88  and has a sharpened end  112 , which acts as a spike for driving into the ground. A flange portion  114  extends at a right angle to the vertical member  110  that incorporates a notch  116 . Due to the complex shape of the member  46 , it is best made from a metal casting. 
     Still referring to FIGS. 1-4 and additionally to FIGS. 4-6, the fitting  36  includes a plug portion  120  that extends into the end  34  of the section  24  of the rail assembly  22  and is bonded thereto. The hook  52  is attached to the plug portion  120 . A shoulder  122  on the fitting  36  abuts the end  34  of the section  24 . The fitting  36  includes a slot  124  and flanged end  126  having a notch  127 . A hole  128  extends through the sides of the fitting in the region of the slot  124 . A stop member  135  for the bushing  62  is rotatably mounted on the bolt outside of the fitting  36 . Forked members  136 A and  136 B having bolt holes  138  through which the bolt  130  extends rotatably, mount the stop member to the fitting  36 . The forked members  136 A and  136 B are joined by a flange  140  that includes a notch  142 . 
     Thus the stop member  135  can be rotated over the section  24  of the rail assembly  22  such that section  24  fits into the notch  142  and the flange  140  extends perpendicular or at right angles to the section  24  of the rail assembly  22 . As will be subsequently discussed, in this position it can stop the aircraft towing member  60  as it is pulled down the rail assembly  22  and the stop members  74 A and  74 B contact the flange  135 . It is believed that the fitting  36  and stop member  135  would best be manufactured as a casting, because of their complex shapes. 
     Also rotatably mounted to the bolt  130  are telescoping supports  146 A and  146 B, typical of those found on camera tripod supports. The supports  146 A and  146 B include end fittings  148  bent at an acute angle  149  having holes  150  for engaging the bolt  130  there through. The telescoping supports  146 A and  146 B include locking devices  152  for setting the length and pads  154  for contact with the ground. Such supports are old in the art and need not be discussed in further detail. Mounted on either side of the end fittings  148  are rubber bushings  156 A and  156 B. These bushings  156 A and  156 B allow the supports  146 A and  146 B to be collapsed about the rail assembly  22  for storage purposes. A cable  158  is attached between the supports  146 A and  146 B to limit separation from each other. 
     Referring to FIGS. 1-9, the aircraft  160  is initially mounted with a two part carrying case  162 , the main portion  163 A supporting the airplane and the cover  163 B. The main portion  163 A of the case  162  incorporates a second half of a hook and loop type fastener  164 . The aircraft  160  is a flying wing design having a longitudinal axis  165 , wings  166 A and  166 B, rudders  170 A and  170 B, elevons  172 A and  172 B, a front end mounting a motor  174  for driving a propeller  176 . Wire loops  178 A and  178 B are installed in the leading edge of the wings  166 A and  166 B spaced apart a distance  180  equal to the distance  68  of the vertical plates  66 A and  66 B the aircraft  160  is supported by a plurality of foam pads  181  within the main portion  163 A of the carrying case  162  such that the aircraft can be easily withdrawn. 
     A pair of bungee cords  184 A and  184 B are tied to the pin  86  at the end  72  of the bushing  62  and at their second end  185 A and  185 B tied to a cord  186 . The cord  186  includes a series of knots  188  spaced along its length. The bungee cords  184 A and  184 B extend down the rail assembly  22 , over the pulley  134  and back along the underside of the rail assembly. 
     Referring to FIGS.  3  and  10 - 12 , a foot petal operated cable release assembly  190  is provided and includes a foot petal assembly  191  having a flexible cable  192  movably mounted within a cable carrier  193 . The end  194  of the cable carrier  193  is inserted into the hole  98  of plug portion  88  and is secured therein by the thumbscrew  100 . The end of the cable  192  terminates in a rigid rod  196  that has the closed loop of rope  84  thereabout and extends into hole  92 . Thus aircraft-towing member  60  can be held in place at the first end of the rail assembly  22 . 
     The foot petal assembly  192  includes an open toped container  200  having a front wall  202 . The front wall  202  includes a hole  204  therethrough for receiving the end  206  of the cable carrier  193 . A thumbscrew  208  mounted in threaded hole  210  is in communication with hole  204 . Thus the cable carrier  194  can be secured to the container  200 . A pair of lugs  212  extend upward from the front wall  202  having holes  214 . A lever arm  216  includes a pair of lugs  218  also having holes  220  therethrough. Fasteners  221  secure the lever arm  216  to the container  200 . A beam  224  is pivotally attached by its first end  226  to the lever arm  216  by means of a fastener assembly  228 , with the second end  229  ending in a curved surface in contact with the bottom of the container  200 . A spring  230  is attached to the front wall  202  and beam  224  biasing the beam toward the front wall. A stop member  232  mounted to the container floor limits forward movement. 
     The end  233  of the cable  192  extends through a hole  234  in the beam  224  and is secured thereto by means of a retainer  238  clamped about the end securing it thereto. A pair of arms  240 A and  240 B are pivotally mounted to the underside of the container  200 , which can be extended to provide support so that any tendency to tip over is eliminated when the foot petal assembly is actuated. Referring to FIGS. 1-4, it can be seen when the operator steps on the lever are  216 , the beam  224  will move away from the front wall pulling the cable  192 . This of course will remove the pin  196  from the hole  92  releasing the loop of rope  84 . 
     Referring to FIGS. 1-12, to “arm” the catapult  20 , the cord  186  is pulled tight and locked in place by “hooking” one of the knots  188  into the notch  116  in the flange portion  114  of the vertical member  110 . The supports  146 A and  146 B are extended so that the front end of the assembly  20  is raised and the sharpened end  112  of the vertical member  110  is driven into the ground. 
     Thereafter, the main portion  163 A of the carrying case  162  with the aircraft  160  installed therein is placed on the flat plate  64  of the aircraft towing member  60  such that the second half  164  of the hook and loop fastener is joined to the first half  107  locking it to the fitting  46 . The wire loops  178 A and  178 B are attached to the hooks  70 A and  70 B on the vertical plates  66 A and  66 B. At this point the aircraft  160  is ready to launch. The operator (not shown) presses on the foot petal causing the cable  192  to retract, releasing the rope  84 . The towing member  60  is then pulled down the rail assembly  22 . 
     As this Occurs, the aircraft  160  is pulled out of the main portion  163 A of the carrying case  162  and it rides on the flat plate  64  from the first end to the second end of the rail assembly  22 . When the stop members  74 A and  74 B hit the stop plane  135 , the hooks  70 A and  70 B automatically separate from the wire loops  178 A and  178 B and the aircraft is catapulted off the plate  64  and into the air. The resilient bumpers  76  cushion the impact. The operator can thereafter start the motor and guide the aircraft via a radio control system (not shown). The use of the foot petal operated release system  190  allows both hands to be used to operate the radio controls. Of courses, the motor could be started prior to launch. 
     To store the catapult  20 , the main portion  163 A carrying case  162  is removed from the towing member  60 , the aircraft  160  is installed and the cover  163 B placed thereover. The cable carrier  193  is disconnected from the member  46  and the bungee cords  184 A and  184 B are disconnected from the member  36 . Referring to FIGS. 13 and 14, the segments  24 ,  26 ,  28  and  30  of the rail assembly  22  are then disconnected and folded. Thereafter, the bungee cords and cord  186  can be wrapped around the fully folded rail assembly. 
     The advantage of the subject catapult system is that it is simple to set up and operate. The aircraft essentially remains protected in a carrying case until launched. Furthermore, the use of a foot petal operated release system frees both hands of the operator. The launch force can be easily adjusted by varying the amount of tension in the bungee cords. In addition, the initial trajectory of the aircraft can be varied. It also folds up into a compact package for storage. Finally, it is inexpensive to manufacture. 
     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.