Abstract:
A lightweight, miniature torpedo has a contact and attachment assembly that is operable to hold the torpedo to a ship&#39;s hull in response to contact with the ship&#39;s hull, a chamber containing a plurality of flammable elements that are sequentially ignited and burn against the ship&#39;s hull at a combustion temperature that is higher than a melting temperature of the material of the ship&#39;s hull, and a propulsion and steering assembly that propels and directs the torpedo through water to the ship&#39;s hull. The torpedo is constructed with a size and weight that enables it to be carried by and launched from an unmanned aerial vehicle.

Description:
FIELD 
     The present invention relates to a miniature torpedo and more particularly, to a lightweight, miniature torpedo that can be carried by and launched from an unmanned aerial vehicle. 
     BACKGROUND 
     Typical anti-ship torpedos are too heavy and too large to be carried by and launched from an unmanned aerial vehicle (UAV). A typical torpedo is constructed using heavy plastique explosives. The amount and type of explosives employed in a typical torpedo add significantly to the torpedo&#39;s size and weight. As typical, small UAVs have a limited payload capacity, the size and weight of typical, larger torpedoes prohibit their use on smaller scale UAV platforms. 
     SUMMARY 
     The miniature torpedo of the present invention overcomes the size and weight disadvantages of conventional torpedoes that prevent them from being carried by and launched from smaller UAVs in addition to significantly increasing the torpedo payload capability of both larger UAVs and conventional manned anti-ship aircraft, and anti sub-surface ship aircraft. The miniature torpedo of the invention has an overall length of approximately 18.5 inches and approximate weight of less than 10 pounds. The miniature torpedo is therefore ideally suited for being carried by and launched from small UAVs while also increasing the torpedo carrying capacity of larger UAVs and conventional manned aircraft. 
     The miniature torpedo of the invention is basically comprised of a contact and attachment assembly, a chamber containing at least one or more flammable element(s), and an ignition assembly for example magnesium or a magnesium alloy. 
     The contact and attachment assembly attaches the torpedo to a ship&#39;s hull. 
     One or more flammable element(s) are moveable by a drive mechanism through the chamber and toward the ship&#39;s hull. 
     The ignition assembly ignites one or more flammable element(s) and releases the ignited element(s) from the chamber. 
     The drive mechanism positions the ignited element against the ship&#39;s hull where the high temperature heat of the burning element(s) melt a hole through the ship&#39;s hull. 
     The miniature torpedo also includes a propulsion and steering assembly that is operable to propel and steer the torpedo through water below the water line. 
     The miniature torpedo also includes a navigation and guidance assembly that controls the propulsion and steering assembly to direct the torpedo through the water toward the ship&#39;s hull. 
     The apparatus also includes a targeting sensor and guidance transducer assembly that intercepts information on a location of the ship&#39;s hull and communicates the information to the navigation and guidance assembly. The navigation and guidance assembly uses the communicated information to control the propulsion and steering assembly to direct the miniature torpedo through the water to the ship&#39;s hull. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further features of the invention are set forth in the following description of the invention and in the drawing figures. 
         FIG. 1  is an illustration of a side view of the apparatus of the invention. 
         FIG. 2  is a front view illustration of the contact and attachment assembly of the apparatus taken from the left side of the apparatus shown in  FIG. 1 . 
         FIG. 3  is a rear view illustration of the contact and attachment assembly shown in  FIG. 2 . 
         FIG. 4  is a side view illustration of the contact and attachment assembly along the line  4 - 4  shown in  FIG. 3 . 
         FIG. 5  is an illustration of the component parts of the hollow universal joint disassembled 
         FIG. 6  is an illustration of the component parts of the hollow universal joint disassembled and rotated 90 degrees from their positions shown in  FIG. 5 . 
         FIG. 7  is an illustration of the hollow universal joint component of the contact and attachment assembly removed from the assembly. 
         FIG. 8  is an illustration of the propulsion and steering assembly of the apparatus. 
         FIG. 8   a  is a side view illustration of a steering assembly fairing having a pivoting rudder removed from the propulsion and steering assembly of  FIG. 8 . 
         FIG. 9  is a rear view illustration of the propulsion and steering assembly taken from the right side of the assembly shown in  FIG. 8 . 
         FIG. 10  is a front view illustration of the propulsion and steering assembly taken from the left side of the assembly as shown in  FIG. 8 . 
         FIG. 11  is an illustration of an alternate embodiment of the torpedo apparatus that employs extended range fairings. 
         FIG. 12  is an illustration of a fairing of the apparatus shown in  FIG. 11  removed from the apparatus. 
         FIG. 13  is an illustration of the apparatus shown in  FIG. 11  with the extended range fairings deployed. 
         FIG. 14  is an additional illustration of an alternate embodiment of the miniature torpedo apparatus that utilizes a high capacity helical housing for containment of a larger volume of flammable element(s). The helical housing embodiment provides for increased lethality of the miniature torpedo. 
     
    
    
     DESCRIPTION 
       FIG. 1  is an illustration of a side view of the miniature torpedo apparatus of the invention  12  showing some of the parts in partial cross-section. The construction of the apparatus  12  to be described is, for the most part, symmetrical around a center axis  14  of the apparatus. The apparatus  12  has an overall axial length from a forward end  16  to a rearward end  18  of the apparatus of approximately 18.5 inches. The component parts of the apparatus  12  are constructed of materials that provide the apparatus  12  with sufficient structural strength for its intended purpose and with the apparatus having an approximate weight of less than 10 pounds. Component parts constructed of specific materials will be identified. 
     The miniature torpedo  12  is basically comprised of a contact and attachment assembly  22  at the forward end  16  of the apparatus, a chamber  24  operatively connected to the contact and attachment assembly  22  and extending rearwardly thereof, and a propulsion and steering assembly  26  operatively connected to the chamber  24  at the rearward end  18  of the apparatus. 
     Referring to  FIGS. 1-4 , a major component part of the contact and attachment assembly  22  is an annular permanent magnet assembly  32 . The magnet assembly  32  comprises one or more substantially flat permanent magnets, annular forward surface  34  and an opposite, substantially flat, annular rearward surface  36 . The magnet assembly surface  34  has a cylindrical interior surface  38  surrounding a center bore through the magnet assembly  32  and a cylindrical exterior surface  42 . The two cylindrical surfaces  38 ,  42  extend axially between the magnet assembly  32  forward  34  and rearward  36  surfaces. The magnet assembly forward surface  34  is positioned to attach the miniature torpedo  12  to the hull of a ship when the surface makes contact with the hull. The flux field of the magnet assembly surface  34  in addition to the 90 degree, rotational flexibility of the hollow universal joint or u-joint assembly  92 , has a sufficient adherence and conformal hydrodynamics to hold the apparatus  12  to a ship&#39;s hull even when the ship is underway through water. 
     Four or more guidance transducer assemblies  44  are secured to the magnet exterior surface  42  at equal circumferentially spaced positions. The transducer assemblies  44  are positioned or oriented parallel with the apparatus center axis  14 . Sonic signal receiving surfaces  46  of the assemblies  44  face forwardly of the apparatus. The guidance transducer assemblies  44  function as target sensors. 
     A sonic navigation guidance assembly  48  is secured to the magnet assembly&#39;s rearward surface  36 . The sonic navigation guidance assembly  48  communicates with and receives signals from the guidance transducer assemblies  44 . 
     A control system  52 , for example, a central processing unit (CPU)  52  is secured to the magnet assembly rearward surface  36 . The CPU communicates with the guidance transducer assemblies  44  and the sonic navigation guidance assembly  48  and controls the operations of these assemblies. The CPU also communicates with the propulsion and steering assembly  26  and controls the operation of this assembly. 
     A power source  54  is also secured to the magnet rearward surface  36 , and, or alongside chamber  24 . The power source  54  is comprised of one or more batteries and communicates with the guidance transducer assemblies  44 , the sonic navigation guidance assembly  48 , the CPU  52  and the propulsion and steering assembly  26  and provides power to all these components. 
     A pair of tethers  114  connects to contact release mechanisms  56 , and are secured to the magnet assembly  32  at diametrically opposite sides of the magnet assembly exterior surface  42 . Each mechanism  56  has a cylindrical housing  58  that is connected to a base  62 . Each base  62  is secured to the magnet assembly&#39;s rearward surface  36 . The cylindrical housings  58  are positioned at diametrically opposite sides of the magnet assembly&#39;s exterior surface  42  with center axes of the cylindrical housings being aligned parallel with the apparatus center axis  14 . A plunger  64  is mounted in each cylindrical housing  58  for axial reciprocating movements forwardly and rearwardly through the housing. Each plunger  64  has a forward contact end  66  and an axially opposite hook end  68 . Springs  72  in the cylindrical housings  54  bias the plungers  64  forwardly to their positions shown in  FIGS. 1 and 4 . 
     A retention and ignition assembly  74  is secured to the magnet assembly  32  at the center of the magnet forward surface  34 . The retention and ignition assembly  74  is formed as a flat strip that extends radially across the magnet assembly center bore and then axially across opposite sides of the magnet assembly&#39;s cylindrical interior surface  38 . The strip  74  is constructed of a material that will ignite and burn when supplied with an electric current, for example magnesium or a magnesium alloy. The strip  74  is connected in communication with the power source  52  through the CPU  54  and its ignition is controlled by the CPU. 
     A cylindrical housing  82  extends into the magnet assembly&#39;s center bore and is secured to the magnet assembly interior surface  38  and to a portion of the magnet rearward surface  36 . The cylindrical housing  82  is shown in  FIGS. 1 and 5 . The cylindrical housing  82  has a smaller cylindrical portion  84  that is fit into and secured to the cylindrical interior surface  38  of the magnet assembly  32 . A larger cylindrical portion  86  of the housing  82  is secured to the magnet assembly rearward surface  36  and projects rearwardly as it intersects retaining ring  102 . The cylindrical housing  82  is constructed of a high heat resistant material, for example a ceramic material. 
     A hollow universal joint or hollow u-joint assembly  92  is secured inside the large portion  86  of the cylindrical housing  82 . The hollow u-joint assembly  92  is comprised of a cylindrical forward portion  94  and a cylindrical rearward portion  96 . The joint forward portion  94  has a bearing ring  98  secured to its exterior surface. The bearing ring  98  interfaces the interior surface of the large portion  86  of the cylindrical housing  82 , thereby operatively connecting the hollow u-joint assembly  92  to the contact and attachment assembly  22 . A retaining ring  102  is press-fit into the large portion  86  of the cylindrical housing  82  to secure the hollow u-joint forward portion  94  to the housing  82 . The bearing ring  98  allows the hollow u-joint assembly  92  to rotate freely about the apparatus center axis  14  relative to the contact and attachment assembly  22 . The retaining ring  102  prevents the u-joint assembly  92  from moving axially relative to the contact and attachment assembly  22 . Referring to  FIGS. 5 ,  6  and  7 , the hollow u-joint assembly forward portion  94  has a pair of rearwardly projecting flanges  104  on diametrically opposite sides of the forward portion. Each of the flanges  104  has a pivot post  106  projecting radially outwardly from the flange. The hollow u-joint assembly rearward portion  96  also has a pair of flanges  108  that project forwardly on diametrically opposite sides of the rearward portion  96 . Each of these flanges  108  has a pivot post hole  112 . As seen in  FIG. 5 , the pivot post  106  of the u-joint forward portion  94  engage in the pivot post holes  112  of the u-joint rearward portion  96  forming a pivoting connection between the two portions that allows the two portions to pivot to a 90 degree angle. 
     Together, the bearing ring  98  and the joint assembly between the joint forward portion  94  and the joint rearward portion  96  form a hollow universal joint between the contact and attachment assembly  22  and the joint rearward portion  96  that enables the joint rearward portion  96  to rotate freely around the center axis  14  of the apparatus  12  and allows the joint rearward portion  96  to move through a 180 degree arc relative to the contact and attachment assembly  22 . 
     A pair of tethers  114  are secured to diametrically opposite sides of the joint assembly rearward portion  96 . The tethers  114  are shown in the drawing figures as small link chains. However, other equivalent flexible cords could be substituted for the link chains. The tethers extend from the joint assembly rearward portion  96  to the plunger hook ends  68  of the harness contact release mechanisms  56 . The springs  72  of the harness contact release mechanisms  56  pull the tethers  114  tight as they extend between the harness contact release mechanisms  56  and the joint assembly rearward portion  96 . In this manner, the tethers  114  hold the joint rearward hollow u-joint assembly  96  in a position relative to the contact and attachment assembly  22  shown in  FIG. 1  and prevent the hollow u-joint assembly rearward portion  96  from pivoting relative to the contact and attachment assembly. 
     The tubular chamber  24  is operatively connected between the contact and attachment assembly  22  and the propulsion and steering assembly  26 . The chamber  24  has a cylindrical exterior surface  116  and a cylindrical interior surface  118 . The chamber  24  has a straight length that extends forward  122  between rearward u-joint assembly  96  and axially opposite rearward end  124  of the chamber. The chamber forward end  122  is open and extends into the joint assembly rearward portion  96  and is secured thereto, thereby operatively connecting the chamber  24  to the contact and attachment assembly  22 . The chamber rearward end  124  is closed and is secured to the propulsion and steering assembly  26 . The chamber  24  has an interior diameter dimension that is substantially the same as that of the joint assembly rearward portion  96 , the hollow u-joint assembly forward portion  94  and the small portion  86  of the cylindrical housing  82 . Thus, there is a continuous interior bore that extends through the chamber  24  from the chamber rearward end  124 , through the joint assembly  92  and through the permanent magnet assembly  32 . 
     A spring drive mechanism  128  is positioned in the chamber  24  at the chamber rearward end  124 . The spring drive mechanism  128  is illustrated in the drawing figures as a coil spring. Other equivalent spring drive mechanisms could be employed instead of the coil spring. The spring drive mechanism  128  is shown in a compressed condition in  FIG. 1 . In its uncompressed condition the spring drive mechanism  128  extends completely through the continuous interior bore defined through the chamber  24 , the hollow u-joint assembly  92  and the magnet assembly  32 . 
     A plurality of flammable elements  132  are contained in the chamber  24 , the hollow u-joint assembly  92  and the cylindrical housing  82 . Adjacent flammable elements  132  are linked together, for example by a short cord (not shown). The spring drive mechanism  128  urges the flammable elements  132  toward the forward end  16  of the miniature torpedo apparatus  12  where a forward end of the elements  132  engages against and is retained by the retention and ignition assembly  74 . Each of the flammable elements  132  has a spherical configuration that can be driven and moved easily through the chamber  24 , the hollow u-joint assembly  92  and the cylindrical housing  82  by the spring drive mechanism  128 . Each of the elements  132  is constructed of a flammable material such as magnesium or a magnesium alloy that can be easily ignited and will oxidize when ignited and burn at a combustion temperature that is sufficiently high to melt through a metal ship&#39;s hull. 
     The propulsion and steering assembly  26  is operable to drive the apparatus  12  through water to a targeted ship&#39;s hull. The assembly  26  is connected in communication with the CPU  52  and operates in response to signals received from the CPU. The assembly  26  includes a pair of electric motors  134  that each drive propellers  136  in rotation. The assembly  26  also includes a pair of pivoting rudders  138  that steer the apparatus  12  through the water in response to signals received from the CPU  52 . 
       FIGS. 11-13  show an alternative embodiment of the apparatus in which a pair of extended range fairings  142  have been added to the apparatus. The fairings  142  are attached to diametrically opposite sides of the chamber  24  by pivoting connections  144 . As shown in  FIG. 11 , the fairings  142  are initially positioned extending along the opposite sides of the chamber  24  when the apparatus is carried by a UAV and launched by the UAV. Once in the water and below the water level, the fairings  142  are deployed to their positions shown in  FIG. 13  where the fairings can increase the range of the miniature torpedo apparatus  12  as it travels through water. 
     An additional alternate embodiment of the apparatus is shown in  FIG. 14 . In this embodiment, the straight tubular chamber  24  is replaced with a helical tubular chamber  148 . The helical tubular chamber  148  increases the number of flammable elements  132  that can be carried by the apparatus. The operation of the embodiment shown in  FIG. 14  is substantially the same as that of the embodiment shown in  FIG. 1  to be described. 
     The apparatus  12  is designed to be carried by a UAV to the general geographic area of a ship detected by a remote acoustic sensor. The apparatus  12  is designed to be effective against both surface ships and sub-surface ships. Following detection of the ship by the remote acoustic sensor, a UAV carrying the apparatus  12  will launch or deploy the apparatus  12  in the general geographic area of the detected ship. A small parachute attached to the apparatus  12  will allow it to slowly fall from the UAV to the water surface. Once in the water, the CPU  52  will control the apparatus  12  to release the parachute, target the ship hull with the guidance transducer assemblies  44  and travel to the targeted hull using the sonic navigation guidance assembly  48  and the propulsion and steering assembly  26 . 
     When the targeted ship hull is reached, the apparatus  12  will attach to the metal of the ship hull by the permanent magnet assembly  32 . Attachment of the magnet assembly  32  to the ship hull depresses the plungers  64  of the harness contact release mechanism  56  causing the tethers  114  to disengage from the plunger hook ends  68  and freeing the hollow u-joint assembly rearward portion  96  to rotate and pivot relative to the contact and attachment assembly  22 . This allows the chamber  24  of the apparatus to rotate around the apparatus center axis  14  and pivot up to 90 degrees to conform the chamber  24  to the hydrodynamic forces of a moving ship hull. The releasing of the harness contact release mechanism  56  also causes the CPU  52  to concurrently trigger the electrical ignition of the retention and ignition assembly  74 . This in turn ignites and releases the forward most of the flammable elements  132  to be moved forwardly by the drive mechanism  128  and engage against the ship hull. Once ignited, the combustion temperature of the flammable element  132  will cause the area of the ship&#39;s hull engaged by the element to melt and will bore through the hull of the targeted ship. As the combustion of one flammable element  132  is completed it ignites the next in line flammable element which is then pressed against the melting area of the ship hull by the drive mechanism  128 . This continues until the burning flammable elements  132  bore a hole through the ship hull. 
     As various modifications could be made in the construction of the apparatus herein described and illustrated and its method of use without departing from the scope of the invention, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. Thus, the breadth and scope of the present invention should not be limited by any of the above described exemplary embodiments, but should be defined only in accordance with the following claims appended hereto and their equivalents.