Abstract:
A simulated land mine for use in a combat simulation or a simulated war game, comprising: a base frame with an opening facing upwards; an inner housing inserted into the base frame and including a first center hole formed vertically therethrough; a gas cylinder mounted in the first center hole and including a second center hole formed vertically therethrough, a gas chamber formed around the second center hole and a discharge aperture communicating the formers and being used for containing compressed gas; a valve mounted in the second center hole for sealing the discharge aperture; a receiving chamber formed at an upper part of the first center hole by the inner housing, the gas cylinder and the valve and being used to contain colored liquid or powder to be ejected; means for supporting the inner housing which enables the movement of the inner housing in relation to the base frame; and a means for actuating the valve to selectively open the discharge aperture to release the compressed gas from the gas chamber into the receiving chamber.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates generally to land mines, and more particularly to land mines for use in a combat simulation or a simulated war game. 
       BACKGROUND OF THE INVENTION 
       [0002]    Currently, to produce a scenario environment for a combat simulation or a simulated war game, simulated land mines are usually used. Such kind of simulated land mine generally involves a gas container containing compressed gas, a liquid container containing colored liquid, and a piercer for piercing the gas container. When the land mine is triggered, the piercer would pierce the gas container to release the compressed gas contained therein, and the released gas would force the colored liquid to eject from the liquid container. Thus, the individuals around the land mine would be marked by the colored liquid as being eliminated from the combat simulation or simulated war game. 
         [0003]    However, as the gas container could no longer contain compressed gas after being pierced, the gas container or even the whole land mine should be replaced. Thus, the cost for the combat simulation or simulated war game would be relatively higher. 
         [0004]    Besides, at the initial stage after the piercer pieces the gas container, the gas would leak out of the gas container slowly due to the existence of the piercer in the hole formed by the piercer on the gas container. Thus, the force of the gas ejecting the colored liquid is not large enough and the sound generated by the leakage of the gas is also not loud enough to generate a vivid explosion scene. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention mainly aims to provide a simulated land mine for use in a combat simulation or a simulated war game to overcome the above-mentioned drawbacks. 
         [0006]    The goal of the present invention is achieved by means of a simulated land mine for use in a combat simulation or a simulated war game, comprising: a base frame with an opening facing upwards; an inner housing inserted into the base frame through the opening and including a first center hole formed vertically therethrough; a gas cylinder mounted in the first center hole of the inner housing, which gas cylinder includes a second center hole formed vertically therethrough, a gas chamber formed around the second center hole and a discharge aperture communicating the gas chamber and the second center hole and being used for containing compressed gas; a valve mounted in the second center hole of the gas cylinder for sealing the discharge aperture; a receiving chamber formed at an upper part of the first center hole by the inner housing, the gas cylinder and the valve and being used to contain colored liquid or powder to be ejected; means for supporting the inner housing which enables the movement of the inner housing in relation to the base frame; and a means for actuating the valve to selectively open the discharge aperture to release the compressed gas from the gas chamber into the receiving chamber. 
         [0007]    The means for supporting the inner housing includes a bracket provided within the base frame and a first spring provided between the bracket and an inner bottom of the base frame for tending to push the bracket away from the inner bottom of the base frame, while the means for actuating the valve is a striker fixedly mounted on the inner bottom of the base frame, which striker extends upwards into a through hole formed at the center of the bracket to align with the valve. 
         [0008]    An advantage of the present invention is that the simulated land mine could be reused by just re-filling the gas chamber with compressed gas and re-filling the receiving chamber with colored liquid or powder, and no component in the land mine needs to be replaced for such reuse. 
         [0009]    Since the inner housing, the gas cylinder and the valve are all supported on the bracket, most of the weight of the land mine is distributed equally on the bracket. Therefore, even when the land mine is stepped on at a corner of the cover, the inner housing together with the gas cylinder and valve could be pressed downwards smoothly without any jam or failure. Thus, a further advantage of the present invention is that the simulated land mine could always be triggered smoothly without any failure. 
         [0010]    Another advantage of the present invention is that the force generated by rapid discharge of the compressed gas is large enough to eject the sufficient colored liquid or powder from the receiving chamber to generate a vivid explosion scene. 
         [0011]    A still another advantage of the present invention is that the rapid discharge of the compressed gas also generate a loud sound to produce a further vivid explosion scene. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    The embodiments of the present invention will be described in detail with reference to the accompanying drawings. The figures are for illustration purposes only and are not drawn to scale, in which, 
           [0013]      FIG. 1  is a cross section view of an embodiment of a simulated land mine according to the present invention; and 
           [0014]      FIG. 2  is a cross section view of a base housing of the simulated land mine of  FIG. 1 ; 
           [0015]      FIG. 3  is a cross section view of an inner housing and a cover of the simulated land mine of  FIG. 1 ; 
           [0016]      FIG. 4  is a cross section view of a gas cylinder of the simulated land mine of  FIG. 1 ; 
           [0017]      FIG. 5  is a explosive view of a valve of the simulated land mine of  FIG. 1 ; and 
           [0018]      FIG. 6  is a cross section view of the simulated land mine of  FIG. 1  during the operation. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0019]    With reference to  FIGS. 1-2 , the reference numeral  1  generally denotes the simulated land mine of the present invention. The simulated land mine  1  comprises a base frame  2  with an opening  21  facing upwards and an inner housing  5  inserted into the base frame  2  through the opening  21 . The inner housing  5  is supported on a bracket  3  provided within the base frame  2 . Between the bracket  3  and an inner bottom of the base frame  2 , a first spring  4  is provided which tends to push the bracket  3  away from the inner bottom of the base frame  2 . With the support of the bracket  3  and first spring  4 , the inner housing  5  is movable in relation to the base frame  2  by pressing or releasing the inner housing  5 . 
         [0020]    Particularly, as shown in  FIG. 3 , the inner housing  5  comprises a first center hole  51  formed vertically therethrough. A cover  6  with a plurality of discharge openings  61  is provided at the top of the inner housing  5  to cover the first center hole  51 . To retain the downward movement of the inner housing  5  with respect to the base frame  2 , a safety pin  10  may be inserted into a wall of the inner housing  5  through the cover  6  and press against the tip of the base frame  2 . After removing the safety pin  10 , the inner housing  5  could move freely with respect to the base frame  2 . 
         [0021]    As shown in  FIGS. 1 and 4 , a gas cylinder  7  is mounted in the first center hole  51  of the inner housing  5 . Preferably, the gas cylinder  7  is mounted in such a manner that the bottom of the gas cylinder  7  is also supported on the bracket  3 . 
         [0022]    The gas cylinder  7  includes a second center hole  71  formed vertically therethrough, and a gas chamber  72  formed around the second center hole  71  and spaced from the center second hole  71  by a spacer  74 . A discharge aperture  73  is formed at an upper part of the spacer  74  for communicating the gas chamber  72  and the second center hole  71 . Preferably, the discharge aperture  73  is a circular aperture formed around the second center hole  71 . A step section  75  is formed on an inner surface of the spacer  74  at a lower part thereof, in which the inner diameter of the second center hole  71  at the step section  75  is slightly smaller than that above this section. An upper circular projection  76  extends inward towards the center of the second center hole  71  above the discharge aperture  73 . At the bottom of the second center hole  71 , a plurality radially spaced apart lower projections  77  are formed around the second center hole  71 . Preferably, the lower projections connect with each other to form a circular projection. A charge valve  78  could be provided in the gas cylinder  7  for charging the gas chamber  72  with compressed gas when the discharge aperture  73  is closed. Any charge valve well known in the art could be used in the present invention, and the detailed description thereof is omitted. The compressed gas could be compressed air or other inert gases or the mixture thereof. 
         [0023]    As shown in  FIG. 1 , the present invention further comprises a valve  8  provided within the second center hole  71  of the gas cylinder  7  for selectively closing the discharge aperture  73 . Therefore, the inner housing  5 , the gas cylinder  7  and the top of the valve  8  form a receiving chamber  11  at an upper part of the first center hole  51 . The receiving chamber  11  is used to contain colored liquid or powder to be ejected from the land mine when the latter is triggered. To enlarge the volume of the receiving chamber, the upper part of the first center hole  51  could have a shape of inverted cone, and preferably the upper part of second center hole  71  of the gas cylinder  7  could also have a shape of inverted cone. 
         [0024]      FIG. 5  illustrates the valve  8  of the present invention in detail. The valve  8  includes a valve body  81  with a blind hole  811  formed at the center of the valve body from the lower side thereof, a valve core  82  partially received in the blind hole  811 , and a second spring  83  provided between the valve body  81  and valve core  82  and tending to separate them from each other. 
         [0025]    A circular protrusion  812  is formed around an outer surface of the valve body  81  at an upper part thereof. The upper end surface of the circular protrusion  812  presses against the circular projection  76  of the gas cylinder  7 , while the diameter and thickness of the circular protrusion  812  are sized to cover the discharge aperture  73  to seal the latter. To seal the discharge aperture  73  tightly, a pair of O-rings  813  may be provided on the valve body  81  above and below the discharge aperture respectively. 
         [0026]    A plurality of radially spaced apart receiving holes  814  are formed through a side wall of the valve body  81  at the lower part thereof. A ball  84  is provided within each of receiving holes  813 . The diameter of the ball  84  is slightly smaller than the inner diameter of its respective receiving hole  814 , but is slightly larger than the distance from the inner surface of the side wall of the valve body to the inner surface of the spacer  74 . The ball could be made of metals, rigid plastics, ceramics, alloys or any other rigid materials. 
         [0027]    The valve core  82  comprises an upper flange  821  and a lower flange  822  formed at an upper and a lower part thereof respectively. The diameter of the upper flange  821  is slightly smaller that that of the blind hole  811  of the valve body  81  to enable the upper flange to be movable freely therein. The lower flange  822  is received on the projections  77  formed at the bottom the second center hole  71 , to support the whole valve  8  within the second center hole. In this case, the second spring  83  push the valve body  81  upwards to enable the upper end surface of the circular protrusion  812  to press against the circular projection  76  of the gas cylinder  7  tightly. At the same time, the upper flange  822  of the valve core  82  presses against the balls  84  received in the receiving holes  814 , and the valve body  81  is thus fixed to the gas cylinder  7  by the force generated from the contact of the balls  84  and the spacer  74 , and the discharge aperture  73  is sealed by the circular protrusion  812  of the valve  8 . Preferably, a discharge hole  823  could be formed in the valve core  82  for discharging gas, liquid or powder entering into the blind hole. 
         [0028]    Return to  FIGS. 1 and 2 , in order to actuate the valve  8  to release the discharge aperture  73  of the gas cylinder  7 , a striker  9  is fixedly mounted on the inner bottom of the base frame  2 . The striker  9  extends upwards into a through hole  31  formed at the center of the bracket  3 , to align with the bottom of the valve core  82 . The tip of the striker  9  is slightly below or flushes with the top surface of the bracket  3 . 
         [0029]    Preferably, a plurality of radially spaced apart projections  32  may extend inward towards the center of the though hole  31  at the lower part of the latter, while a flange  91  may be formed at the upper part of the striker  9 . Therefore, the flange  91  of the striker  9  presses against the projections  32  of the bracket  3 , to limit the distance the bracket  3  is pushed away from the inner bottom of the base frame  2  by the first spring  4 . Preferably, the projections  32  may connect with each other to form a circular projection. 
         [0030]    The operation of the simulated land mine of the present invention is described in detail with reference to  FIG. 6 . 
         [0031]    At first, the land mine of the present invention is set in the ground with the gas chamber  72  filled with compressed gas and the receiving chamber  11  filled with the colored liquid or powder. Then, the safety pin  10  is removed from the land mine to allow the movement of the inner housing  5  with respect to the base frame  2 . When a participant in the combat simulation or simulated war game steps on the cover  6  of the land mine (as indicated by arrow A in the  FIG. 6 ), the inner housing  5  would be pressed and moved downwards together with the bracket  2  with respect to the base frame  2  against the first spring  4 , thus, the gas cylinder  7  attached to the inner housing  5  and the valve  8  supported on the gas cylinder  7  would also be moved downwards together with inner housing  5 . 
         [0032]    As shown in  FIG. 6 , as the inner housing  5 , the gas cylinder  7  and the valve  8  are all supported on the bracket  2 , most of the weight of the land mine is distributed equally on the bracket  2 . Therefore, even when the land mine is stepped on at a corner of the cover  6 , the inner housing  5  together with the gas cylinder  7  and valve  8  could be pressed downwards smoothly without any jam or failure. 
         [0033]    At this time, the striker  9  protrudes from the through hole  31  of the bracket  3  to contact the valve core  82  of the valve  8 , thus the valve core  82  is prevent from further moving downwards. Subsequently, with the further downward movement of the valve body  81  together with the gas cylinder  8 , the valve core  82  is pushed upwards with respect to the valve body  81 , and the upper flange  822  thereof would move across the balls  84  of the valve  8  and release the pressure applied on the balls  84 . With the release of the pressure on the balls  84 , the force generated by the contact of the balls and spacer  74  is lowered or even disappears, and then the valve body  81  could not be tightly attached to the gas cylinder  7  any longer. 
         [0034]    Consequently, the pressure applied on the valve body  81  by the compressed gas in the gas chamber  72  forces the valve body  81  to move downwards rapidly against the second spring  83 , thus the discharge aperture  73  is opened. When the balls  84  is further moved downwards by the valve body  81  to reach the step section  75  of the spacer  74 , they would be moved inwards into the receiving hole  814 . Thus, the valve body  81  would be further moved downwards to open the discharge aperture  73  completely. Then, the compressed gas is discharged rapidly from the gas chamber  72  through the discharge aperture  73 , and the rapid discharge of compressed gas eject the colored liquid or powder contained in the receiving chamber  11  through the discharge openings  61  of the cover  6  (as indicated by the arrow B in the  FIG. 6 ) and generate loud sound at the same time. The participants around the land mine would be stained by the ejected liquid or powder as being eliminated from the combat simulation or simulated war game. 
         [0035]    After the cover  6  is released and the air pressure within the gas chamber  72  is balanced to the external air pressure with the discharge of the compressed gas, the bracket  3  is pushed upwards by the first spring  4  to move away from the inner bottom of the base frame  2 . Thus, the inner housing  5  supported on the bracket  3  as well as the gas cylinder  7  and valve  8  would be also moved upwards by the bracket  3 . Subsequently, the valve core  82  separates from the striker  9 , thus the second spring  83  of the valve  8  forces the valve body  81  and valve core  82  to move away from each other. Thus, the lower flange  823  of the valve core  82  is pushed upwards to press against the projections  77  and be supported on the latter, while valve body  81  is pushed upwards to press against the circular projection  76  of the gas cylinder  7  to seal the discharge aperture  73 . At the same time, the upper flange  822  of the valve core  82  moves downwards onto the balls  84  and press the balls  84  tightly against the spacer  74  of the gas cylinder  7 . 
         [0036]    After the gas chamber  72  is re-charged with compressed gas and the receiving chamber is re-filled with colored liquid or powder, the simulated land mine of the present invention could be reused without replacement of any components thereof. 
         [0037]    Although the description of the present invention is made with reference to the preferred embodiments, the present invention is not limited to these embodiments. Various modifications and changes can be made to the invention by those skilled in the art without departing from the spirit and scopes of the present invention.