Patent Publication Number: US-6701819-B1

Title: Apparatus for launching an object in a fluid environment

Description:
STATEMENT OF GOVERNMENT INTEREST 
     The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor. 
     CROSS REFERENCE TO OTHER PATENT APPLICATIONS 
     Not applicable. 
     BACKGROUND OF THE INVENTION 
     (1) Field of the Invention 
     The present invention generally relates to an apparatus for launching an object in a fluid environment. 
     (2) Description of the Prior Art 
     Devices and systems for launching objects, weapons or vehicles into the ocean or other fluid or liquid environments are known in the art. For example, such devices are used to launch or eject buoys at relatively deep depths from a submerged submarine. Some of these devices and systems for launching objects are described in U.S. Pat. Nos. 3,476,048, 3,516,380, 4,185,345 and 5,918,307. One particular well known prior art system uses gas generators to launch objects underwater. One such system is described in U.S. Pat. No. 5,981,307 entitled “Underwater Projectile Launcher”. U.S. Pat. No. 5,981,307 discloses that the launcher described therein can use any of the well known types of chemical energy storage—solid, liquid or gaseous propellants—for generating the gas required to launch the projectile. 
     Typically, many launching systems currently in operation utilize solid propellants. In such systems, the solid propellant is ignited and gas is generated from the burning propellant. This gas is used to effect the device launch. One significant problem with such systems is that the solid propellant is highly flammable and explosive and must be handled with great care. This problem creates additional cost and expense associated with handling and storage of the solid propellant, and significantly increases the time it takes to initiate and effect a safe and successful launch of an object. 
     What is needed is an apparatus for launching an object into a fluid environment that eliminates the aforementioned deficiencies of the prior art systems which utilize gas generation to launch an object into a fluid environment. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to an apparatus for launching an object into a fluid environment such as oceans, rivers, lakes, or any fluid or liquid contained within any man-made structure or made-made earthen works. In one embodiment, the apparatus comprises a tubular member having a forward muzzle end and an opposed rearward end. The tubular member has a longitudinally extending axis, an interior region for receiving an object to be launched, an exterior wall confronting the fluid environment and an interior wall. The apparatus further includes expellable members for closing the forward muzzle end and rearward end of the tubular member, at least one flood valve member located on a corresponding expellable member for enabling fluid confronting the exterior wall to flood the interior region so as to equalize forces on the interior and exterior walls of the tubular member, and an object contact member disposed within the interior region and movable along the longitudinally extending axis. The object contact member contacts and moves the object when a propelling force is applied to the object contact member. The apparatus further includes a propellant device for producing the propelling force. The device contains a gas generator and is configured to generate gas in controlled amounts that are sufficient to propel the object contact member in the direction of the forward muzzle end. The apparatus further includes a control device that controls the flood valve member, the expellable members and the propellant device in accordance with a predetermined timed sequence wherein the control device first controls the flood valve to allow fluid to flood the interior region. Thereafter, the control device causes the expellable members to be expelled from the forward muzzle end and rearward end. Thereafter, the control device controls the propellant device to release generated gas in successive bursts so as to produce a continuous propelling force that causes the object contact member to propel the object through the tubular member, out through the forward end muzzle and into the fluid surrounding the tubular member. The successive bursts of generated gas are preferably uniform, continuous and stable thereby resulting in a fully stable ejection of the object at a relatively high exit velocity. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The features of the invention are believed to be novel and the elements characteristic of the invention are set forth with particularity in the appended claims. The figures are for illustration purposes only and are not drawn to scale. The invention itself, however, both as to organization and method of operation, may best be understood by reference to the detailed description which follows taken in conjunction with the accompanying drawings in which: 
     FIG. 1 is a combination side-elevational view, partially in cross-section, and schematic diagram of the apparatus of the present invention; 
     FIG. 2 is a combination side-elevational view, partially in cross-section, and schematic diagram of one embodiment of the apparatus of the present invention; and 
     FIG. 3 is a view taken along line  3 — 3  in FIG.  2 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In describing the preferred embodiments of the present invention, reference will be made herein to FIGS. 1-3 of the drawings in which like numerals refer to like features of the invention. 
     Referring to FIG. 1, there is shown apparatus  10  of the present invention. Apparatus  10  generally comprises tubular member  12  which has forward muzzle end  14  and opposed rearward end  16 . Tubular member  12  has longitudinally extending axis  18  and interior region  20  for receiving object  22  (e.g. vehicle, torpedo, weapon, buoy, hydroplane, etc.) that is to be launched into the fluid environment surrounding apparatus  10 . Tubular member  12  can be made from any rigid material including metals, composites and plastics. As used herein, the term “fluid environment” includes oceans, rivers, lakes, or any body of fluid or liquid contained within any man-made structure or made-made earthen works. In one embodiment, tubular member  12  comprises a barrel. Such a barrel is described in U.S. Pat. No. 5,918,307. Apparatus  10  includes clamping device  23  that allows tubular member  12  to be attached to the hull of a vessel such as a ship, submarine or any other vessel or device that travels through such a fluid environment. In one embodiment, clamping device  23  is configured to allow tubular member  12  to be releasably attached to the vessel. Such a configuration enables tubular member  12  to be released from the vessel after object  22  is launched. 
     Referring to FIG. 1, tubular member  12  has interior wall  24  and exterior wall  26  confronting the fluid environment. Apparatus  10  includes a muzzle expellable member  28  and breech expellable member  30  for closing the forward muzzle end  14  and opposed rearward end  16  of tubular member  12 . 
     Referring to FIG. 1, apparatus  10  further comprises flood valve members  32  for enabling fluid external to tubular member  12  to flood interior region  20  in a controlled manner so as to minimize water hammer effects, especially at relatively deep depths. One flood valve member  32  is located on expellable member  28 . The other flood valve member  32  is located on expellable member  30 . Although the foregoing description is in terms of two flood valves  32 , it is to be understood that apparatus  10  can utilize just one flood valve  32  or more than two flood valves  32 . Flood valve or valves  32  can be positioned on tubular member  12  in an alternate embodiment. In a preferred embodiment, each flood valve  32  comprises an exploding valve that is exploded upon receipt of an electrical control signal. Once flood valve  32  explodes, fluid enters interior region  20 . 
     Apparatus  10  includes a plurality of exploding bolts  34  for attaching muzzle expellable member  28  to the forward muzzle end  14  and breech expellable member  30  to the opposed rearward end  16 . Exploding bolts  34  are exploded upon receipt of an electrical control signal. Explosion of bolts  32  propels expellable members  28  and  30  away from tubular member  12 . 
     Referring to FIG. 1, apparatus  10  further comprises object contact member  36  disposed within interior region  20  and movable along longitudinally extending axis  18 . Object contact member  36  contacts at contact surface  37  and moves object  22  when a propelling force is applied to the object contact member  36 . In one embodiment, object contact member  36  is generally cylindrical in shape and defines an interior space  38 . In a preferred embodiment, object contact member  36  comprises a sabot. 
     In an alternate embodiment of apparatus  10 , tubular member  12  includes a rail (not shown) that longitudinally extends within interior region  20 . In such an embodiment, object contact member  36  is movably mounted on the rail. 
     As shown in FIG. 1, apparatus  10  further includes propellant device  40  for producing a propelling force. Propellant device  40  is disposed within interior space  38  of object contact member  36 . Device  40  produces a propelling force that propels object contact member  36 . In accordance with the present invention, propellant device  40  is a plurality of chemical or hybrid gas generators and is configured to release generated gas via exit or exhaust opening  41  in controlled amounts that are sufficient to propel object contact member  36 . Device  40  includes an electrical interface  42  that is configured to receive an electrical control signal that effects generation of the gas. The propelling force resulting from the release of the gas propels object contact member  36  and object  22  in the direction indicated by arrow  43  and toward forward muzzle end  14 . Prior to the generation of gas from device  40 , object contact member  36  is positioned so that device  40  is located near opposed rearward end  16 . 
     Referring to FIGS. 2 and 3, in one embodiment, gas generator device  40  comprises a plurality of chemical gas generators  44  wherein each gas generator  44  can generate a predetermined amount of gas that is emitted from exit or exhaust opening  45  of each device  44 . Gas generators  44  can be chemical gas generators or hybrid gas generators incorporating a chemical gas generator with compressed gas. Compressed gas, in standard packaging, does not have sufficient energy density to effect a launch. Each generator  44  includes an electrical interface  46  for receiving an electrical control signal that effects generation of the gas in the corresponding gas generator device  44 . As shown in FIG. 2, exit  45  of each device  44  faces breech expellable member  30 . Referring to FIG. 3, in a preferred embodiment, the plurality of gas generators  44  are symmetrically arranged. In one embodiment, each gas generator  44  comprises a canister containing a gas generating compound or a gas generating compound and a compressed gas as is well known in the art of automobile airbag inflation devices. For the purpose of simplicity, wires  48  are not, shown in FIG.  3 . 
     Referring to FIG. 1, apparatus  10  further comprises control device  47 . Control device  47  is preferably located on board the vessel, ship or other device to which tubular member  12  is attached. Control device  47  contains electrical circuitry and electronic components that generate electrical signals that are transferred by wires  48  to explosive bolts  34 , explosive flood valves  32 , and interface  42  of device  40 . Control device  47  is configured so the electrical signals are generated in a predetermined order and are separated by a predetermined time duration. In such a configuration, control device  47  first produces electrical signals that cause explosive valves  32  to is flood interior region  20  so as to equalize the pressures on interior wall  24  and exterior wall  26  of the tubular member  12 . After a predetermined amount of time has elapsed which is sufficient to allow interior region  20  to completely flood, control device  47  outputs electrical signals that cause explosion of explosive bolts  34  so as to expel expellable members  28  and  30  from forward muzzle end  14  and opposed rearward end  16 , respectively. After a predetermined amount of time has elapsed which is sufficient to allow expellable members  28  and  30  to fall away from tubular member  12 , control device  47  outputs electrical signals to interface  46  of device  40  to enable device  40  to generate gas in successive bursts so as to produce a continuous propelling force that is applied to object contact member  36 . As a result, object contact member  36  propels object  22  through tubular member  12  and out through forward muzzle end  14 . If device  40  is comprised of the plurality of gas generators  44  as shown in FIGS. 2 and 3, then wires  48  are connected to each electrical interface  46  of each gas generator  44 . In such a configuration, control device  44  generates electrical signals in a predetermined timed sequence so that each gas generator  44  generates gas in accordance with the predetermined timed sequence. In one embodiment, the predetermined timed sequence effects generation of gas from each gas generator  44  in a sequential order. 
     The gas generators  44  produce sufficient thrust to create a continuous, even, and stable ejection force during the entire launch of object  22  and causes object  22  to have a relatively high exit velocity as it exits tubular member  12 . Since expellable member  30  is expelled from tubular member  12  before the compressed gas is released, the full thrust produced by the released gas is utilized to accelerate object  22  during launch without any thrust being used to overcome sea pressure. Thus, the plurality of gas generators  44  located within interior space  38  of object contact member  36  in conjunction with the predetermined time sequence in which each generator  44  generates its gas results in a full-power stroke ejection of object  22 . 
     If control device  47  is located on board the vessel or ship, then clamping means  23  is configured to include an electrical interface that is electrically connected to wires  48 . 
     The present invention provides many other benefits and advantages. Specifically, apparatus  10  reduces the danger associated with explosive solid and liquid propellants. Furthermore, the design of apparatus  10  is relatively less complex than prior art systems and, therefore, can be implemented at relatively lower costs and with commercially available components. Additionally, apparatus  10  provides a consistent, continuous and even propelling force that is applied to the object during the entire launch process thereby resulting in a full-stroke ejection of the object. Apparatus  10  also provides for relatively high exit velocity of the object as it leaves tubular member  12 . Apparatus  10  eliminates any impact related to varying sea pressures (or ship depths). 
     Although foregoing description is in terms of apparatus  10  being used in a fluid environment, it is to be understood that apparatus  10  can be used in gaseous environment wherein object  22  is launched in the gaseous environment. 
     While the present invention has been particularly described, in conjunction with a specific preferred embodiment, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. It is therefore contemplated that the appended claims will embrace any such alternatives, modifications and variations as falling within the true scope and spirit of the present invention.