Abstract:
A restraining net launching device includes a planar restraining net which is tightly packed into a cylindrical shape having an outside portion. This restraining net, when planar or unfurled, includes a perimeter which is heavier than a remainder of the net. A launcher is provided in which the packed net is loaded, and from which the packed net is launched toward a target when desired. The launcher includes rifling which engages the outside portion of the packed net during launching. A source of propelling gas is used for propelling the tightly packed restraining net out of the launcher during launching. When the launching device is fired, the rifling of the launcher engages the outside portion of the packed restraining net to cause the tightly packed restraining net to rotate about the longitudinal axis and hence to unfurl after exiting the launcher with the heavier perimeter radially outermost.

Description:
FEDERAL RESEARCH STATEMENT 
   The inventions described herein may be manufactured, used and licensed by or for the U.S. Government for U.S. Government purposes. 

   BACKGROUND OF INVENTION 
   Law enforcement and military personnel have applications requiring the restraining of individuals and animals. A variety of devices have been developed over the years to ballistically deliver restraining nets. The key difference being the method used for unfurling and deploying the net in flight. For example, the net gun disclosed in U.S. Pat. No. 4,912,869 uses a plurality of barrels to launch projectiles with diverging flight paths to drag the net package to the target and deploy the net in flight. In the ballistically deployed restraining system disclosed in U.S. Pat. No. 5,988,036, a spreader charge and weights is used to spread the net in flight. 
   SUMMARY OF INVENTION 
   In accordance with the present invention, a restraining net ballistic launching device is provided which includes a planar restraining net which is tightly packed into a cylindrical shape having an outside portion. This restraining net, when planar or unfurled, includes a perimeter which is heavier than a remainder of the net. A launcher is provided in which the packed net is loaded, and from which the packed net is launched when desired. The launcher includes rifling which engages the outside portion of the packed net during launching. Finally, there is provided a source of propelling gas for propelling the tightly packed restraining net out of the launcher during launching. Thus, when the launching device is fired, the rifling of the launcher engages the outside portion of the packed restraining net to cause the tightly packed restraining net to rotate about the longitudinal axis and hence to unfurl after exiting the launcher with the heavier perimeter radially outermost. 
   In one preferred embodiment, the launcher includes an elongate launch cup in which the packed net is located. This launch cup includes a rear wall, an open front, an elongate barrel wall extending between the rear wall and the open front, and rifling along an interior surface of the barrel wall. In addition, a hollow extension projects from the rear wall of the launch cup. Then, in this preferred embodiment, the source of propelling gas is a muzzle to which the extension of the launch cup is attached for transferring a propelling gas formed in the muzzle into an area adjacent the rear wall of the launch cup. Preferably, the launcher also includes a gas seal member in the launch cup located between the packed net and the rear wall of the launch cup. 
   In another preferred embodiment, the launcher includes a gun barrel having a rifled bore and a rear breech. Received in this breech is a cartridge case in which the packed net is located. This cartridge case includes a rear wall and an open front. Then, in this preferred embodiment, the source of propelling gas is a charge provided in the cartridge case between the packed net and the rear wall. Preferably, the launcher also includes a gas seal member located between the packed net and the charge, and the cartridge case also includes a protective cap which covers the open front thereof. 
   In a further preferred embodiment, the launcher includes a gun barrel having a smooth bore and a rear breech. Received in this breech is a cartridge case in which the packed net is located. This cartridge case includes a rear wall, an open front, and rifling along an interior wall of the cartridge case between the rear wall and the open front. Then, in this preferred embodiment, the source of propelling gas is a charge provided in the cartridge case between the packed net and the rear wall. Preferably, the launcher also includes a gas seal member located between the packed net and the charge, and the cartridge case also includes a protective cap which covers the open front thereof. 
   It is an advantage of the present invention that a ballistically deployed restraining net is provided which is launched in a manner similar to other specialty projectiles. 
   It is also an advantage of the present invention that centrifugal forces created by rifling which engages the packed restraining net are used to cause the ballistically fired restraining net to unfurl in flight to a target. 
   It is a further advantage of the present invention that the spinning of the restraining net to unfurl it in flight provides a simple and economical mechanism to ballistically deploy a restraining net. 
   Other features and advantages of the present invention are stated in or apparent from detailed descriptions of presently preferred embodiments of the invention found hereinbelow. 

   
     BRIEF DESCRIPTION OF DRAWINGS 
       FIG. 1  is a cross-sectional side view of a restraining net launcher prior to firing in accordance with the present invention. 
       FIG. 2  is a cross-sectional side view of the restraining net launcher of  FIG. 1  after initiation of firing. 
       FIG. 3  is a cross-sectional side view of the restraining net launcher of  FIG. 1  after firing as the restraining net moves along the launcher. 
       FIG. 4  is a cross-sectional side view of the restraining net launcher of  FIG. 1  just after exiting of the restraining net from the launcher. 
       FIG. 5  is a perspective rear, top and side view of the restraining net launching device using the restraining net launcher of  FIG. 1  further after exiting of the restraining net from the launcher, and the restraining net is also shown in broken lines as the restraining net unfurls during flight to the target. 
       FIG. 6  is a cross-sectional side view of a second embodiment of a restraining net launching device prior to firing in accordance with the present invention. 
       FIG. 7  is a cross-sectional side view of a third embodiment of a restraining net launching device prior to firing in accordance with the present invention and further with a longitudinal portion of the interior elements of the cartridge case shown cut away. 
   

   DETAILED DESCRIPTION 
   With reference now to the drawings in which like numerals represent like elements throughout the views, a first embodiment of a restraining net launching device  10  is schematically depicted in  FIG. 5 . Launching device includes a launcher  12  from which a planar restraining net  14  has just been deployed, with restraining net also shown unfurled in broken lines in  FIG. 5  as net  14  flies towards a target. As shown in  FIGS. 1–4 , which show various stages of the firing of launcher  12  as discussed below, restraining net  14  is initially tightly packed into a cylindrical shape and loaded into a launch cup  16  of launcher  12 . Launch cup  16  includes a rear wall  18 , an open front  20 , an elongate barrel wall  22  extending between rear wall  18  and open front  20 , and rifling  24  along an interior surface  26  of barrel wall  22  with which an outer portion  29  of packed net  14  is engaged or pressed against. 
   It will be appreciated that, when restraining net  14  is unfurled as depicted in broken lines in  FIG. 5 , restraining net  14  includes a perimeter  28  which is heavier than a remainder of restraining net  14 . In the embodiment depicted in  FIG. 5 , heavier perimeter  28  is provided by making the lines comprising perimeter  28  of a heavier gauge or diameter than lines of the remainder of restraining net  14 . This is satisfactory for a net which is made of connected lines as typical. However, is the net were made of some other material where this was not convenient or desired, perimeter  28  could be made heavier by the addition of weights, a separate border, or the like. Where weights are used, such weights should be made of a somewhat soft material so that impact of the weights with a target will not damage the target, such as rubber. It will also be appreciated that various materials can be used to make up net  14 , such as nylon or KEVLAR, so that with higher strength materials a smaller resulting packed net and hence launch cup  16  would be required. 
   Launch cup  16  also includes a hollow extension  30  projecting from rear wall  18 . Extension  30  is designed to connect to a source  32  of a propelling gas to transfer the gas into launch cup  16 . In this embodiment, the source  32  is a muzzle  34  of a gun as known in the art which is designed to ignite a propelling gas charge which travels up muzzle  34  and into extension  30 . An adapter mechanism as also known in the art is used to attach extension  30  to muzzle  34 , so that other devices besides launcher  10  requiring a ballistic charge can also be used with muzzle  34  as desired. 
   As shown in  FIGS. 1–4 , located between rear wall  18  of launch cup  16  and packed net  14  is a gas seal member  36 . Seal member  36  includes a peripheral flange  38  extending rearwardly from a main body  40  to ensure a good gas tight seal behind seal member  36  when the propelling gas is introduced into launch cup  16 . 
   In operation, launching device  10  functions in the following manner. It will be appreciated that launching device  10  is typically carried separate from muzzle  34  and is only attached thereto when firing of net  14  is desired, or at least in anticipation of the firing of net  14 . Thus, for convenience, launching device  10  is shown in  FIG. 1  in position on muzzle  34  ready for firing. In  FIG. 2 , source of gas  32  has just been ignited and a hot/expanding gas  42  is just entering into the volume behind gas seal member  36 . Due to the pressure of hot gas  42 , gas seal member  36  and packed net  14  are pushed along launch cup  16 , with the outer portions of flange  38  and packed net  14  engaging rifling  24  along interior surface  26  of launch cup  16 . Engagement of rifling  24  causes packed net  14  and seal member  36  to spin in the direction noted by the arrow in  FIG. 3 . Upon exiting launch cup  16 , seal member  36  separates from packed net  14  and packed net  14  begins to expand due to centrifugal force from the packed state. As net  14  flies forward and spins, heavier perimeter  28  causes net  14  to unfurl into its full expanded form as shown by the dashed lines in  FIG. 5  so that net  14  is in position to impact and immobilize a target (not shown). On the other hand, gas seal member  36  loses stability after exiting open front  20  and soon drops harmlessly to the ground. 
   Depicted in  FIG. 6  is a second embodiment of a launching device  50  in accordance with the present invention. In this embodiment, launching device  50  includes a launcher  52  which is formed by a gun barrel  54  having a bore  56  with rifling  57  therealong and a rear breech  58 . Conveniently, launcher  52  is a conventional launcher used for a variety of ballistically propelled devices as known in the art and typically launcher  52  is provided adjacent a common rifle barrel, but launcher  52  could also be a dedicated launcher as known in the art as well. Located in breech  58  of launcher  52  is a self-contained cartridge case  60 . Cartridge case  60  includes a rear wall  62 , an open front  64 , and an interior wall  66  extending between rear wall  62  and open front  64 . A packed net  70  similar to packed net  14  as described above is located inside of cartridge case  60 . 
   Located rearward of packed net  70  is a gas seal member  72  which in this embodiment is a flat disk. Behind gas seal member  72  is a charge  74  of a suitable propellant powder, which is ignited in the conventional manner by firing pin mechanism  75  engaging a primer  76  located in rear wall  62 . Preferably, to protect packed net  70  and to make cartridge case  60  self-sealed, a protective cap  78  made of plastic or the like is provided to cover and seal open front  64 . 
   In operation, launching device  50  functions in substantially the same manner as launching device  10  described above. In particular, after firing of launcher  52 , rifling  57  engages an outer portion of packed net  70  as packed net  70  exits cartridge case  60 . This causes packed net  70  to have a rotation as it exits gun barrel  54  and flies towards the target, and hence for packed net  70  to unfurl during flight due to centrifugal forces in the same manner as packed net  14  described above. It will be appreciated that protective cap  78  is pushed out of gun barrel  54  ahead of packed net  70  and flies harmlessly out of the way or breaks up due to its shape or composition, and likewise gas seal member  72  also loses stability and soon drops harmlessly to the ground. 
   Depicted in  FIG. 7  is a third embodiment of a launching device  80  in accordance with the present invention. In this embodiment, launching device  80  includes a launcher  82  which is formed by a gun barrel  84  having a smooth bore  86  and a rear breech  88 . Conveniently, launcher  82  is another conventional launcher used for a variety of self-propelled devices as known in the art and typically provided adjacent a common rifle barrel, but launcher  82  could be a dedicated launcher as well. Located in breech  88  is a self-contained cartridge case  90 . Cartridge case  90  includes a rear wall  92 , an open front  94 , and an interior wall  96  extending between rear wall  92  and open front  94 . It will be appreciated that one half of the elements inside of cartridge case  90  have been longitudinally cut away to better show interior wall  96 , and in particular that located along interior wall  96  from rear wall  92  (or at least adjacent thereto) to open front  94  is a rifling  98 . A packed net  100  similar to packed net  14  or packed net  70  as described above is located inside of cartridge case with the outside portion thereof in engagement with rifling  98 . 
   Located rearward of packed net  100  is a gas seal member  102  which in this embodiment is also a flat disk. Behind gas seal member  102  is a charge  104  of a suitable propellant powder, which is ignited in the conventional manner by firing pin mechanism  105  engaging a primer  106  located in rear wall  92 . Preferably, to protect packed net  100  and to make cartridge case  90  self-sealed, a protective cap  108  made of plastic or the like is provided to cover and seal open front  94 . 
   In operation, launching device  80  functions in substantially the same manner as launching devices  10  and  50  described above. In particular, at firing of launcher  82  (and of course prior thereto), rifling  98  engages an outer portion of packed net  100  as packed net  70  begins to move along and to exit cartridge case  90 . This causes packed net  100  to have a rotation as it exits open front  94 , which rotation is maintained as it moves along gun barrel  84  and flies towards the target. Hence, packed net  100  unfurls during flight in the same manner as packed nets  14  and  70  described above. It will be appreciated that, like protective cap  78 , protective cap  108  is pushed out of gun barrel  84  ahead of packed net  100  and flies harmessly out of the way or breaks up due to its shape or composition, and likewise gas seal member  102  also loses stability and soon drops harmlessly to the ground. 
   While the present invention has been described with respect to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that other variations and modifications can be effected within the scope and spirit of the invention.