Abstract:
A fixture is provided for supporting load from weapons recoil, being mountable on a flat bed of a road vehicle disposed on ground. The flat bed can receive a weapons mount. The vehicle has longitudinal, lateral and vertical orientations. The fixture includes a box brace, a recoil platform, first and second brackets, first and second beams, first and second posts and a deck. The box brace extends in the lateral direction. The recoil platform is parallel to the brace. The first and second brackets extend from the platform in the longitudinal direction. The beams are disposable parallel to the brace. The beams are translatable in the lateral direction. The first and second posts extend in the vertical direction downward from respective the first and second beams. The deck can receive the weapons mount, and is disposable on the platform and the brackets. The posts are retractable for stowage and extendible for raising the flat bed above the ground.

Description:
STATEMENT OF GOVERNMENT INTEREST 
       [0001]    The invention described was made in the performance of official duties by one or more employees of the Department of the Navy, and thus, the invention herein may be manufactured, used or licensed by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor. 
     
    
     BACKGROUND 
       [0002]    The invention relates generally to vehicular support for a weapons platform. In particular, the invention relates to stands with retractable legs for shock absorption while firing. 
       SUMMARY 
       [0003]    Conventional vehicle supports for weapon systems yield disadvantages addressed by various exemplary embodiments of the present invention. In particular, various exemplary embodiments provide a fixture for supporting load from weapons recoil, being mountable on a flat bed of a road vehicle disposed on ground. The flat bed can receive a weapons mount. The vehicle has longitudinal, lateral and vertical orientations. 
         [0004]    In exemplary embodiments, the fixture includes a box brace, a recoil platform, first and second brackets, first and second beams, first and second posts and a deck. The box brace extends in the lateral direction. The recoil platform is parallel to the brace. The first and second brackets extend from the platform in the longitudinal direction. 
         [0005]    In exemplary embodiments, the beams are disposable parallel to the brace. The beams are translatable in the lateral direction. The first and second posts extend in the vertical direction downward from respective the first and second beams. The deck can receive the weapons mount, and is disposable on the platform and the brackets. The posts are retractable for stowage and extendible for raising the flat bed above the ground. Other various embodiments alternatively or additionally provide for stabilizing legs mounted to the deck. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    These and various other features and aspects of various exemplary embodiments will be readily understood with reference to the following detailed description taken in conjunction with the accompanying drawings, in which like or similar numbers are used throughout, and in which: 
           [0007]      FIGS. 1A and 1B  are perspective views of an exemplary platform-carrying truck; 
           [0008]      FIG. 2  is a first perspective view of a platform fixture; 
           [0009]      FIG. 3  is a second perspective view of the platform fixture; 
           [0010]      FIG. 4  is a detail perspective view of the fixture; 
           [0011]      FIG. 5  is a perspective view of an optional wheel mount; 
           [0012]      FIG. 6  is a perspective view of a fixture leg; 
           [0013]      FIG. 7  is a third perspective view of the platform fixture on the truck; 
           [0014]      FIG. 8  is an elevation view of the platform fixture on the truck; 
           [0015]      FIGS. 9A and 9B  are perspective views of the truck with a base; 
           [0016]      FIGS. 10A through 10D  are side elevation views of the truck and fixture; and 
           [0017]      FIGS. 11A and 11B  are rear elevation views of the truck and fixture. 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    In the following detailed description of exemplary embodiments of the invention, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific exemplary embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments may be utilized, and logical, mechanical, and other changes may be made without departing from the spirit or scope of the present invention. The following detailed description is therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims. 
         [0019]    The Naval Surface Warfare Center Dahlgren Division (NSWCDD) has been tasked by the Office of the Secretary of Defense (OSD) to determine the feasibility of integrating an Enhanced Mortar Targeting System (EMTAS) onto a wheeled tactical platform or truck vehicle. The vehicle&#39;s suspension supports the recoil of the EMTAS with minor or no modifications done to the vehicle, which has the capability to store 120 mm rounds and extra charges. The vehicle has the means to lift the EMTAS off the vehicle&#39;s flat bed and setting the vehicle on the ground if needed for firing operation. 
         [0020]    The Mobile Modular Weapon Platform Fixture System (MMWPFS) constitutes a system in which all these components together work in conjunction in unison to absorb extremely high recoil forces generated by the weapon system and transmit them to the ground surface without causing damage to the vehicle, Conventional platforms for a weapon system are available for a specific military vehicle but cannot be utilized outside the vehicle, leading to operational damage to vehicles and platform structure. 
         [0021]      FIGS. 1A and 1B  show perspective views  100  of an exemplary vehicle assembly disposed on the ground  110  with a compass rose  120  that indicates longitudinal (x), lateral (y) and vertical (z) directions. The longitudinal directional points forward; the lateral direction points port and the vertical (or azimuth) direction points upward. The military vehicle  130  (e.g., truck) includes a cab  140  (for seating driver and/or passenger), a truck flat bed  150  and wheels  160 . In the assembly, the flat bed  150  includes the Mobile Modular Weapon Platform Fixture System (MMWPFS) or fixture  170 . 
         [0022]      FIG. 2  shows a perspective view  200  of the fixture  170  as deployed for positioning on the ground  110 . The stand  170  includes a deck  210  with hand rail  220 , and is supported by legs  230  and a stand  240 . The deck  210  includes a plurality of holes along the periphery and as a mesh on the surface to facilitate attachments of auxiliary equipment. A ladder  250  can be connected to enable personnel to climb from the ground  110  to the deck  210 . 
         [0023]      FIG. 3  shows a detail perspective view  300  of the fixture  210 . The stand  240  includes port and starboard lateral posts  310  and  320 , each of which connects to an extension beam: a fore beam  330  and an aft beam  340 . The stand  240  further includes an attachment plate  350  for mounting to the flat bed  150 . The stand  240  optionally includes detachable recoil wheel mounts  360  that attach to the posts  310  and  320  and enable repositioning the stand  240 . 
         [0024]      FIG. 4  shows a detail perspective view  400  of the fixture  170  with the stand  240 . A box beam brace  410  reinforces longitudinal stability against sudden forces from weapons firing. The extension beams  330  and  340  extend parallel and adjacent to the beam brace  410 . A horizontal plate  420  connects the beam brace  410  to a recoil box platform  430  with a damper  435  therebetween. The recoil platform  430  supports the deck  210 . A pair of longitudinal brackets  440  extend forward (i.e., perpendicular) from the recoil platform  430  to support a bottom plate  445 . An extendible slide rail  450  attaches to each bracket  440 . For the fixture  170  installed on the vehicle  130 , the box brace  410 , recoil box and damper  435  are longitudinally oriented parallel to the lateral (y) direction of the compass rose, and similarly the brackets  440  and rails  450  are longitudinally oriented parallel to the longitudinal (x) direction. 
         [0025]    Vertical plates  460 ,  465  and  470  separate the extension beams  330  and  340  from the beam brace  410 , with springs and dampers therebetween. For the fixture  170  connected to the vehicle  130 , these plates  350 ,  460 ,  465  and  470  are perpendicular to the (x) longitudinal direction. A mid-post  480  extends downward from the beam brace  410 , as the lateral posts  310  and  320  extend from their respective beams  330  and  340 . The posts  310 ,  320  and  480  engage the ground  110  by recoil shoes  490  and are lengthwise adjustable for vertical retraction and extension. The brace  410 , platform  430 , and beams  330  and  340  have rectangular cross-sections and are composed of steel. The plates  460 ,  465  and  470  also comprise steel, as do the posts  310 ,  320  and  480 . 
         [0026]      FIG. 5  shows a perspective view  500  of the wheel mount  360 . An annular trunk  510  is disposed around the post  310 . Lateral branches  520  extend radially from the trunk  510 . A stem  530  extends from each respective branch parallel to the trunk  510 . An axle  540  mounts to each stem  530 . A tire wheel  550  that can engage the ground  110  attaches to each axle  540 .  FIG. 6  shows a perspective view  600  of each leg  230 , which is adjustable in length. The leg  230  includes an upper portion  610  and a lower portion  620  that telescopes into or out of the upper portion  610 . The lower portion  620  terminates in a pad  630  that engages the ground  110 . The fixture  170  typically includes three legs  230  when deployed. While in transit by the vehicle  130 , the legs  230  can be stowed. 
         [0027]      FIG. 7  shows a perspective view  700  of the fixture  170  mounted to the flat bed  150  of the vehicle  130 . A pivotable mortar base  710  can be disposed on the deck  210 . The base  710  constitutes the turn table for the EMTAS.  FIG. 8  shows a side elevation view  800  of the fixture  170  mounted to the flat bed  150 . The compass rose  120  shows the orientation of the vehicle  130  facing to the right (and port away from the viewer). The legs  230  and stand  240  elevate the wheels  160  off the ground  110  and dispose the deck  210  a specified vertical distance (e.g., 73.93 inches) therefrom. The deck  210  slideably connects to the flat bed  150  by the brackets  440  and the recoil platform  430 . The legs  230  attach to the deck  210 , or alternatively to the bottom plate  445 , by hook brackets  810  that can connect and detach as needed. 
         [0028]      FIGS. 9A and 9B  show perspective views  900  (analogous to  FIG. 1B ) of the vehicle  130  with the stand  170 .  FIG. 9A  shows the deck  210  including the turn table base  710 .  FIG. 9B  shows such a weapon  910  mounted on a saddle  920  disposed on the base  710  that attaches to the deck  210 . The mortar  910  constitutes, for example, a Recoiling Mortar System RMS6-G or else an RMS 6-L.  FIGS. 10A ,  10 B,  10 C and  100  show side elevation views  1000  (analogous to  FIG. 8 ) of the vehicle  130  with the stand  170 . 
         [0029]      FIG. 10A  shows the fixture  170  attaching to the vehicle  130  with posts  310 ,  320  and  480  retracted for road transport.  FIG. 10B  shows the posts  310 ,  320  and  480  extended and the wheels  160  elevated above the ground  110 .  FIG. 10C  shows the legs  230  engaged between the stand  210  and the ground  110 , and the ladder  250  installed.  FIG. 10D  shows the vehicle  130  moving away (i.e., forward) from the fixture  170 , as deployed,  FIGS. 11A and 11B  show rear elevation views  1100  of the vehicle  130  and the fixture  170 , with the compass rose  120  showing the vehicle  130  facing forward away from the viewer.  FIG. 11A  shows the fixture  170  as stowed for road transport, with the posts  310 ,  320  and  480  retracted.  FIG. 11B  shows the fixture  170  deployed for shock absorption, with the beams  330  and  340  extended outward and the posts  310 ,  320  and  480  extended downward. 
         [0030]    The typical setup time when transporting and using the MMWPFS to fire the weapon (e.g., mortar  910 ) is reduced approximately by half (ground fire or attached to vehicle  130 ). Also the fixture  170  can be attached or carried on the rear of a government vehicle for quick transportation and operation for Forward Operating Base (FOB). In view  200 , each individual post  310 ,  320  and  480  can be operated manually using hand cranks and gears, or else hydraulically or with an electric motor. The deck  210  can be pushed in and retracted up by turning the winch on the vehicle  130  such as a jack. 
         [0031]    Conventionally, no currently fielded platforms enable a large weapon system to: 1) be easily transported on a variety of vehicles; 2) fire while being transported; and 3) fire from the ground  110  without major alterations. Conventional systems enable large weapon systems to be either ground fired or vehicle fired, but not both. The ground fired systems are also unable to be used while being transported. 
         [0032]    Exemplary embodiments enable the weapon system, e.g., mortar  910 , to be fired from the vehicle  130  during transport without dismounting. The deck  210  can be adjusted vertically by approximately 5 inches from the ground  110 . Whichever weapon system that is integrated adds approximately 4 feet to each of these values (6 feet from the ground  110  or 9 feet from the ground  110  when fired on the flat bed  150  of the vehicle  130 . When fired off the rear of the vehicle  130 , the fixture  170  is able to receive all the recoil force. Analysis was performed on the EMTAS and MMWPFS using the 5-ton truck (M1083) Family Medium Tactical Vehicle (FMTV) family. The RMS6-G Recoil Mortar (EMTAS) can be fired off the fixture or off the top of a flat bed  150  of the vehicle  130 . 
         [0033]    A Dynamic Finite Element Analysis (FEA) has been performed on the M1083 truck to determine whether the vehicle&#39;s frame and suspension system could withstand the EMTAS or RMS 6L (120 mm Mortar) 40 metric ton recoil forces when fired off the top of the flat bed  150 . The analysis showed that the recoil forces are so strong that the frame structure would be damaged when fired. Some sort of reinforcement would be necessary underneath the weapon system in order to transmit the forces directly to the ground  110  without depending on the vehicle&#39;s structure. Also the reaction of the recoil forces is so rapid that the suspension system cannot react on time and the shocks of the system would bottom out and suffer severe damage. A static Finite Element Analysis (FEA) was performed on the MMWPFS using the Structural Steel (ASTM-A36) series steel, and the results were acceptable. The fixture  170  can withstand approximately 40 metric tons of recoil forces. 
         [0034]    Human system integration provides the hand rail  220  to reduce personnel hazard from falling off the deck  210  and the ladder  250  to enable an operator to climb onto the deck  210  or the flat bed  150 . The deck  210  has several hole mounts in order to accommodate any rail or weapon system that could withstand the recoil forces when fired therefrom (e.g., 81 mm, 120 mm Mortar, 2.75 rocket motor 19/7 tube launcher, Small UAV Drone, or else a base as a lookout tower by using armor instead of the hand rail  220 ). 
         [0035]    The recoil platform  430  provides spring action to absorb some of the recoil forces transmitted from the weapon (in x, y and z) motion that are then reduced through recoil containment plates  460 ,  465  and  470 , which are designed to reduce the recoil forces of the weapon  910  as these forces are transmitted to the ground  110 . Within and between these plates  460 ,  465  and  470 , this recoil containment constitutes an array of part working together in unison (e.g., springs, shock absorbers, rubber mounts, etc.) to absorb that vibrational energy. The pair of extendable beams  330  and  340 , splaying in the lateral (y) direction, assist to stabilize the vehicle  130  and the fixture  170  when firing the mortar weapon  910 . 
         [0036]    A triplet of vertically adjustable recoil posts (i.e., one center  480  and two adjacent  310  and  320 ) level the MMWPFS system. These posts  310 ,  320  and  480  are adjustable to different heights to act as a strong column in transmitting all the recoil forces to the ground  110 . Three recoil shoes  490  receive the recoil forces from the posts  310 ,  320  and  480  and distribute those forces to the ground  110 . The three sets of retractable stabilizer legs  230  and their pads  630  to engage the ground  110  provide stability for the MMWPFS and the vehicle  130  in the longitudinal (x) and lateral (y) directions when the mortar  910  is fired. 
         [0037]    A universal mount  710  on the deck  210  with little or no modification made to attach and transport the MMWPFS with a Marine (MTVR), Army (FMTV), or Air force vehicle (tri-service). The removable recoil legs  230  are used to move the vehicle  130  (short distance), and the MMWPFS on a level ground  110  without a vehicle  130  for easy installation when attaching to vehicle  130  or to row on to the vehicle platform. The Mobile Modular Weapon Platform System is intended to provide a stand for integration with an existing military vehicle that would enable the operation of a weapon system directly from or off from the vehicle, as well as withstand the weight, and recoil farces of the weapon without damage to platform, weapon system and vehicle structure. 
         [0038]    The principal feature of the Mobile Modular Weapon Platform System is the ability to utilize the mass of the top carriage to help moderate double recoil forces. Two recoil systems are involved the primary system of the gun, which is directly affected by the dynamic of the round and the secondary system of the top carriage that controls the impetus of the primary system. This fixture  170  has the flexibility of being used while mounted directly to varieties of military vehicle  130  and also independently. The fixture  170  can withstand the weight and recoil forces in order to prevent damage to the deck. 
         [0039]    While certain features of the embodiments of the invention have been illustrated as described herein, many modifications, substitutions, changes and equivalents will now occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the embodiments.