Abstract:
A mobile aircraft launcher includes a towable, tiltable, wheeled trailer, a launch beam comprising a plurality of sections hinged to one another, an aircraft-engaging shuttle mounted on the launch beam, and a shuttle-moving drive arrangement mounted on the trailer. The launch beam is mounted on the trailer and is movable between a folded, transport condition, in which the beam sections are generally side-by-side, and a launch condition, in which the beam sections are colinear. In the colinear arrangement, a portion of the launch beam extends forward of the trailer, that portion being supportable entirely through the trailer.

Description:
The present invention relates to launchers for aircraft and, more particularly, to compact lightweight mobile aircraft launchers capable of quick setup. 
     BACKGROUND OF THE INVENTION 
     Mobile launchers are known for launching lightweight aircraft, especially unmanned aircraft, but have the drawback of being too large and heavy and too slow or difficult to set up for launch. 
     SUMMARY OF THE INVENTION 
     By the present invention, an exceptionally lightweight and compact mobile aircraft launcher comprises a trailer which can be towed by a lightweight vehicle, such as the Hgh Mobility Multipurpose Wheeled Vehicle (HMMWV). The launcher is capable of launching aircraft having weights of as much as 400 pounds or more. The launcher can be quickly and easily changed from a folded, transporting condition to a deployed, launching condition at a level attitude by one person. 
     The structure which gives the aircraft launcher of the present invention the foregoing advantages includes a launch beam having multiple beam sections hinged to one another. When deployed for launch, one beam section remains fixed to the trailer, while another beam section folds forward and two other beam sections fold rearward. Jacks provided at the leading and trailing ends of the trailer support the trailer and the launch beam at the proper attitudes for transport, deployment and launch. The jacks are retractable for transporting the trailer and are adjustable to move the trailer between the proper attitudes for deployment and the proper attitude for launch. Beam sections are secured on the trailer in their folded positions by stowage straps. 
     The jacks are adjustable in height to change the attitude at which they support the trailer and the launch beam. For deployment of the launch beam, the jacks are adjusted to support the launch beam in a horizontal attitude so that the beam sections can be pivoted about their hinges without gravity tending to make them swing or increasing the force needed to pivot them. After the beam sections have been pivoted to their colinear positions and locked there, the jacks are adjusted to support the launch beam in an inclined attitude (approximately 10 degrees) for launch. When the launch beam is in a horizontal attitude, the launch beam is no more than about 5 feet above a ground surface supporting the trailer so that the beam sections can be pivoted by a person standing on the ground surface. 
     An electrical power unit including gel cell batteries and a charging system is mounted on the trailer for powering an aircraft starter, providing ground power for the UAV and powering the trailer mounted hydraulic system. The trailer mounted hydraulic system consists of a fluid reservoir, control valves, a launch cylinder with integrated accumulator, a latch release cylinder, a nitrogen tank and an electrically driven hydraulic pump. Equipment for arresting a landing aircraft is releasably secured to the trailer, the arresting equipment including an arresting pendant to extend across a runway, energy absorbers to which ends of the pendant are connected, stakes to hold the absorbers in place, and a sledge hammer for driving and removing the stakes. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the aircraft launcher of the present invention in a launch position; 
     FIG. 2 is an enlarged perspective view of the aircraft launcher of FIG. 1 in a folded position; 
     FIG. 3 is an enlarged perspective view of a rearmost beam section of the aircraft launcher of FIG. 1; 
     FIG. 4 is an enlarged perspective view of a rear intermediate beam section of the aircraft launcher of FIG. 1; 
     FIG. 5 is an enlarged perspective view of a forward intermediate beam section of the aircraft launcher of FIG. 1; 
     FIG. 6 is a enlarged perspective view of a forwardmost beam section of the aircraft launcher of FIG. 1; 
     FIG. 7 is an enlarged perspective view of the aircraft-engaging shuttle of the aircraft launcher of FIG. 1; 
     FIG. 8 is an enlarged perspective view of the hydraulic-pneumatic assembly of the aircraft launcher of FIG. 1; 
     FIG. 9 is a side elevation of an alternate embodiment of the aircraft launcher of the present invention in a horizontal attitude; and 
     FIG. 10 is a top plan view of the aircraft launcher of FIG.  9 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     As can be seen from FIGS. 1 and 2, the mobile aircraft launcher according to the present invention, which is designated generally by the reference numeral  10 , comprises a trailer  12  towable by a lightweight vehicle, such as an HMMWV. The trailer  12  includes a trailer bed  14 , a single wheel axle  16 , and wheels  18  and tires  20  mounted at opposite ends of the axle. A conventional trailer hitch  22  extends from one end of a frame  24  supporting the trailer bed  14  for connection to a towing vehicle. 
     A launch beam  26  comprising a plurality of beam sections  28 ,  29 ,  30  and  31  is mounted above the trailer bed  14  by a plurality of supports  36  and  38 . The beam sections  28 - 31  include a rearmost beam section  28 , a rear intermediate beam section  29 , a forward intermediate beam section  30  and a forwardmost beam section  31 . “Forward” and “rearward” as used herein are with respect to direction of launch of the aircraft. They are opposite of the terms “forward” and “rearward” with respect to the direction of the trailer  12  when the trailer is being towed. The forward intermediate beam section  30  is secured to the beam supports  36  and  38 . The other beam sections  28 ,  29  and  31  are not secured directly to the beam supports  36  and  38 , but rather are connected to one another by hinge connections. More specifically, the forwardmost beam section  31  is connected by a hinge  40  to a forward end of the forward intermediate beam section  30 ; the rear intermediate beam section  30  is connected by a hinge  40  to the rear end of the forward intermediate beam section  29 ; and the rearmost beam section is connected by a hinge  40  to the rear end of the rear intermediate beam section  29 . Each of the hinges  40  is arranged such that the beam sections  28 - 31  pivot about generally vertical hinge axes. Over-the-center latch devices  42  of a conventional type are provided at the hinge connections to secure the launch beam sections in a colinear arrangement defining the rectilinear launch beam. The beam sections  28 - 31  are shown in greater detail in FIGS. 3-6. 
     The launch beam  26  defines a slot  44  in its upper surface to receive a shuttle  46  for movement along the launch beam, the shuttle having wheels  47  (FIG. 7) captured between horizontal flanges of the launch beam. The shuttle  46  is connected to a cable  48  extending around sheaves  50  in a conventional revving manner, an opposite end of the cable  48  being attached to a 5 to 1 cable revving system assembly. Sliding sleeves of the revving system are connected to a hydraulic cylinder assembly  82 , which provides the driving force for the shuttle. The shuttle  46  supports the fuselage of the aircraft and engages under and behind the wings to catapult the aircraft forward under the power of a hydraulic/pneumatic assembly  52 . 
     Two front jacks  54  (one of which is shown) are secured to the front end of the trailer  12  at opposite corners, the jacks being pivotally connected to the trailer at the top of the jacks and being movable between a deployed position, as in (FIG.  2 ), in which the jacks contact a ground surface, and a retracted, or stowed, position, in which the jacks are clear of the ground surface. A rear jack  56 , pivotally connected to the trailer at a rear end of the trailer, is shown stowed in FIGS. 1 and 2. The front jacks  54  and the rear jack  56 , which are all of a conventional type, are all adjustable for height, so that the trailer  12  can be tilted and supported about the single wheel axle  16 . 
     Adjustable launch beam jacks  58  are mounted at the rear of the launch beam  26  and are moveable between a stowed position, as in FIG. 3, and a deployed position, as in FIG. 1, in which the launch beam jacks support the launch beam in its inclined, launch position. A forward support strut  60  and a rearward support strut  62  extend from brackets  64  secured on the trailer  12  to, respectively, brackets  66  and  68  (FIG. 3) secured to the launch beam  26 , where the struts are releasably connected by, for example, pins (with detent balls) extending through aligned apertures. In the transport condition of the launcher  10 , the support struts  60  and  62  are positioned in two of the beam sections  28 - 31 , in the slot  44 . 
     A shuttle brake strap  70  of conventional design has one end secured in a brake strap tension mechanism  71  (FIG. 4) anchored to the launch beam  26 , the shuttle brake strap being guided by guides  72  and pulleys  73  (FIGS. 4 and 6) and extending across the path of the shuttle  46  near the forward end of the launch beam to decelerate and stop the shuttle  46  after the launch of the aircraft. 
     In the folded position shown in FIG. 2, the beam sections  28 - 31  are shown in a folded, side-by-side arrangement in which opposite ends of each beam section lie in substantially the same vertical planes as the opposite ends of each of the other beam sections. As a result, the overall length of the launcher  10  in the folded position is minimized. As can best be seen from FIGS. 1 and 8, tie-down supports  74  extend horizontally and transversely across the trailer  12  to support the beam sections  28 ,  29  and  31  in their folded positions. Straps,  76  such as conventional cargo straps, are secured to the forward intermediate beam section  30  to maintain the other beam sections in their folded positions. The trailer lunette  22  extends beyond the ends of the beam sections  28 - 31  and all other portions of the launcher  10  to facilitate connection of the launcher  10  to a towing vehicle. 
     It can be seen from FIG. 8 that the hydraulic/pneumatic assembly  52  includes a tank  78  for compressed nitrogen or other gas connected by a pipe  80  to an actuator/accumulator  82  which contains a piston to provide a driving force for the cable  48  pulling the shuttle. The hydraulic/pneumatic assembly  52  is mounted on the trailer bed  14  among the beam supports  36  and  38  and under the tie down supports  74 . When the launch beam  26  has been deployed and the aircraft positioned on shuttle  46 , the shuttle is held at the rear of the launch beam by a release mechanism. In this condition, hydraulic oil is pumped into the actuator/accumulator  82  to tension the cable  48 . This action causes the separator piston in the actuator/accumulator to move to energize the gas stored in tank  78 . In order to launch the aircraft, the shuttle release mechanism  84  is actuated. 
     Although no showing is made for the embodiment of FIGS. 1-8 of the launch beam in an extended position at a horizontal attitude, such a showing is made in FIG. 9 for an alternative preferred embodiment. The alternate preferred embodiment shown in FIGS. 9 and 10 may show additional details not indicated in FIGS. 1-8. The extended position at horizontal attitude and the details in FIGS. 1-8 are the same as those shown in FIGS. 9 and 10, unless they are specifically indicated to be different in FIGS. 1-8. The most significant difference between the embodiment of FIGS. 1 and 8 and the embodiment of FIGS. 9 and 10 is that the launch beam  26 ′ of the embodiments of FIGS. 9 and 10 is perforated to further decrease the weight of the launcher  10 ′. 
     In moving the launcher  10  from a folded, transport position, such as that shown in FIG. 2, to an extended position, such as that shown in FIG. 9, the front jacks  54  and the rear jack  56  front jacks are deployed and adjusted to orient the beam sections  28 - 31  at a horizontal attitude. In the horizontal attitude, the beam sections  28 - 31  are no more than about five feet above the ground surface supporting the trailer  12 . The horizontal attitude and the height limitation of about five feet facilitate the movement of the beam sections between the folded position and the extended position. Limiting the height of the beam sections in the horizontal attitude makes it relatively easy for one person to pivot the beam sections about their pivot axes while standing on the ground. The horizontal attitude eliminates the tendency of the beam sections to swing about their pivot axes under the influence of gravity. Such a tendency is a danger where the beam sections are inclined at the time of folding or extending, especially in view of their significant weight. The beam sections and most other parts of the launcher are ordinarily made of aluminum and steel. 
     Additional equipment is mounted on the trailer  12  to make the launcher  10  self-sufficient for launching and retrieving operations. The additional equipment includes energy absorbers  86  releasably secured to the trailer  12  by any of a number of conventional arrangements. As can be seen from FIGS. 1 and 2, the energy absorbers  86  include housings defining horizontal apertures. Pins extending horizontally from a bracket mounted on the trailer  12  are received in the horizontal apertures of the absorber housings. The pins have transverse openings at their outer ends, and ball-detent pins  88  attached to the trailer by lanyards  90  are releasably received in the transverse openings. A pendant for extending across a runway is held in a container on the trailer  12 , and stakes  94  and a sledgehammer  96 , best seen in FIG. 10, are releasably secured to the trailer by resilient straps, or other conventional arrangements. 
     It will be apparent to those skilled in the art and it is contemplated that variations and/or changes in the embodiments illustrated and described herein may be made without departure from the present invention. Accordingly, it is intended that the foregoing description is illustrative only, not limiting, and that the true spirit and scope of the present invention will be determined by the appended claims.