Patent Publication Number: US-7581954-B2

Title: Firearms training simulator simulating the recoil of a conventional firearm

Description:
CROSS-REFERENCED TO RELATED APPLICATION 
   This application is a continuation-in-part of U.S. patent application Ser. No. 09/756,891, filed Jan. 9, 2001 now U.S. Pat. No. 6,820,608 entitled “Compressed Gas Powered Gun Simulating the Recoil of a Conventional Firearm.” 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This application relates to firearm training simulators. More specifically, the invention provides a firearms training simulator duplicating the recoil of a conventional firearm, and providing indicia of the path of a bullet if such a bullet had been fired from a conventional firearm. 
   2. Description of the Related Art 
   Firearms training for military personnel, law enforcement officers, and private citizens increasingly encompasses role playing and decision making in addition to marksmanship. Such training often includes competing against role players and/or responding to situations projected onto a screen in front of the trainee. Although self-healing screens exist, permitting the use of conventional firearms for such training, the use of such a system requires a location appropriate to the use of conventional firearms. Furthermore, such systems are expensive and can be unreliable. 
   To increase the number of locations where such training may be safely conducted, and to provide a safe means of force on force role playing, alternatives to conventional firearms have been developed. These alternatives include paintball, Simunitions, and the use of a laser to show the path a bullet would have taken had one been fired. Such alternatives, however, do not duplicate all of the characteristics of a conventional firearm, thereby limiting the extent to which the training will carry over to the use of conventional firearms. The characteristics of a firearm that should be duplicated include size, weight, grip configuration, trigger reach, trigger pull weight, type of sights, level of accuracy, method of reloading, method of operation, location and operation of controls, and recoil. 
   Of all of these characteristics, recoil is the most difficult to duplicate. The inability to get a trainee accustomed to the recoil generated by a conventional firearm is one of the greatest disadvantages in the use of various firearm training simulators. Recoil not only forces the shooter to require the sights after shooting, but also forces the shooter to adapt to a level of discomfort that is proportional to the energy of the cartridge for which the firearm is chambered. Recoil is significantly more difficult to control during full automatic fire than during semi-automatic fire, making the accurate simulation of both recoil and cyclic rate critical in ensuring that simulator training carries over to the use of actual firearms. 
   An example of a presently available firearms training simulator is disclosed in U.S. Pat. No. 5,857,854, issued to Y. Kwalwasser on Jan. 12, 1999, disclosing a recoil simulator for a weapon. The recoil simulator includes a barrel having a plug therein, with an air inlet opening disposed just behind the plug. A piston is reciprocally mounted within a cylinder inside the barrel, with either the piston or the cylinder being stationery, and the other component being attached to a bolt. Upon detection of the firing hammer operation by a sensor, compressed air is directed into the air inlet opening, thereby driving back the bolt against the spring to produce a felt recoil. In an alternative embodiment, the piston and reciprocating bolt may be located within a gas tube above the barrel. A laser generator may be provided at the muzzle end of the barrel. The level of recoil generated is adjusted by modifying the length of travel of the piston and bolt, or the cylinder and bolt, depending upon the embodiment used. 
   U.K. Patent Application Number 2 319 076 A, published on May 13, 1998, discloses a device for cycling a training gun. The device includes a cylinder that is inserted into the barrel of the gun. A piston is reciprocally mounted within the cylinder and is spring biased towards a forward position. Upon the firing of a gas cartridge, the application recites that compressed gas will flow through a bore within the piston into a chamber forward of the piston, thereby driving the piston rearward with sufficient force to cycle a semi-automatic firearm. However, the compressed gun would also apply forward pressure on the piston, making it unlikely that this device would work as described. 
   U.S. Pat. No. 2,023,497, issued to W. Trammel on Dec. 10, 1935, discloses a shooting training device having a spring biased plunger, which, upon pulling the trigger, impacts a movable butt plate within the shoulder stock to simulate recoil. A beam of light is projected from the barrel to show the path that would be followed by a bullet fired from the barrel. A mechanically driven projector may be used in conjunction with the training gun to project a spot of light on a screen to be used to the target, and optionally a second spot of light to show the correct lead distance. The use of a movable butt plate is unrealistic in that the shooter&#39;s hands cannot be used to control recoil. 
   U.S. Pat. No. 4,829,877, issued to J. E. Zerega on May 16, 1989, discloses an accessory for converting a small bore firearm into a theatrical stage prop. The device includes a barrel having a rearwardly spring biased mass therein, and a plurality of passages parallel to and surrounding the barrel. Upon the firing of a blank cartridge, the expanding gases push the spring biased mass forward, until the mass has reached a position where it no longer blocks the entrance to the passages surrounding the barrel. The expanding gases then travel though these passages, back into the barrel beyond the spring for the mass, and out the muzzle. The spring drives the mass rearward, thereby simulating recoil. This would result in a recoil that is delayed as compared to the recoil of an actual firearm, because the mass must first move forward against spring pressure before moving rearward. 
   U.S. Pat. No. 2,708,319, issued to W. A. Tratsch, on May 17, 1955, discloses an air rifle recoil simulator. The recoil simulator includes a spring biased piston within the shoulder stock, and an air passage extending from a valve to a location in front of the piston. Upon pulling the trigger, compressed air pushes the piston rearward against the spring, thereby simulating recoil. The use of a movable butt plate is unrealistic in that the shooter&#39;s hands cannot be used to control recoil. 
   U.S. Pat. No. 4,380,437, issued to G. W. Yarborough, Jr., on Apr. 19, 1983, discloses a small weapon simulator. The simulator includes a laser beam for simulating the path of a bullet. A muzzle-rise module releases a downwardly directed jet of air from the forward portion of the gun to simulate muzzle-rise. Recoil is simulated through an air pressure driven piston pushing against the butt plate. A sound module having an audio speaker simulates the noise of a rifle firing a bullet. The use of a movable butt plate is unrealistic in that the shooter&#39;s hands cannot be used to control recoil. 
   U.S. Pat. No. 5,244,431, issued to B. M. D&#39;Andrade on Sep. 14, 1993, discloses a recoiling toy pistol. Upon the pulling of the trigger, a weight is pushed against a spring in one direction, and then is released to travel rearward under spring pressure, thereby simulating recoil. A weight moved by a single finger can hardly produce a realistic level of recoil. 
   U.S. Pat. No. 4,725,235, issued to J. E. Schoeder et al. on Feb. 16, 1988, discloses a marksmanship training apparatus. The apparatus includes a shoulder stock insert having a solenoid impacting a kick plate in response to trigger activation. The use of a movable butt plate is unrealistic in that the shooter&#39;s hands cannot be used to control recoil. 
   Accordingly, there is a need for a firearms training simulator duplicating the recoil of a conventional firearm. Additionally, there is a need for a firearms training simulator duplicating the full automatic cyclic rate of a conventional full automatic firearm. There is a further need to combine these characteristics into a firearms training simulator that may be used safely within a wide variety of locations, making training facilities easier and more economical to construct, lowering the cost of ammunition and training, reducing noise levels, and facilitating legal ownership. 
   SUMMARY OF THE INVENTION 
   The present invention provides a firearms training simulator providing a recoil similar to that of a gun firing a powder propelled projectile. The simulator may include a means for projecting a laser beam along the path of a bullet that would have been discharged from an actual firearm. The simulator also duplicates many other features of a conventional firearm, for example, the sights, the positioning of the controls, and method of operation. One preferred embodiment simulates the characteristics of an AR-15 or M-16 rifle, although the invention can easily be applied to simulate the characteristics of other conventional firearms. 
   The operation of a firearms training simulator of the present invention is controlled by a combination of the trigger assembly, bolt, buffer assembly, and valve. Preferred embodiments may be capable of semi-automatic fire and full automatic fire. Preferably, the cyclic rate of full automatic fire approximately duplicates the cyclic rate of a conventional automatic rifle. Alternatively two different full automatic cyclic rates may be provided. 
   The trigger assembly includes a trigger having a finger-engaging portion and a selector-engaging portion, a selector switch, a trigger bar, a sear trip, and a sear. The selector switch will preferably be cylindrical, having three bearing surfaces corresponding to safe, semi-automatic fire, and full automatic fire at a low cyclic rate, and a channel corresponding to full automatic fire at a high cyclic rate. These surfaces and channel of the selector bear against the selector engaging portion of the trigger, permitting little or no trigger movement if safe is selected, and increasing trigger movement for semi-automatic fire, low cyclic rate full automatic fire, and high cyclic rate full automatic fire, respectively. The sear is mounted on a sliding pivot, and is spring-biased towards a rearward position. The sear has a forward end for engaging the sear trip, and a rear end for engaging the bolt. The bolt preferably contains a floating mass, and reciprocates between a forward position and a rearward position. Although the bolt is spring-biased towards its forward position, the bolt will typically be held in its rearward position by the sear except during firing. 
   The valve assembly includes a reciprocating housing containing a stationary forward valve poppet, a sliding rear valve poppet, and a spring between the front and rear valve poppets. The spring pushes the rear valve poppet rearward, causing the rear poppet to bear against the housing, thereby closing the rear valve and pushing the housing rearward. Pushing the housing rearward causes the housing to bear against the front valve poppet, thereby closing the front valve. 
   Before the trigger is pulled, the trigger is in its forwardmost position, the bolt is held to the rear by its engagement with the sear, and the sear, although spring-biased rearward, is pushed towards its forwardmost position by the bolt. Pulling the trigger causes the trigger bar to move rearward, pivoting the sear trip upward. The upward movement of the sear trip pushes upward on the forward end of the sear, causing the rearward end of the sear to move down. The bolt is then free to travel forward, where the bolt strikes the rear valve, thereby moving the rear valve relative to the housing and opening the rear valve. Air pressure between the O-ring on the bolt face and the O-ring on the rear of the valve housing causes the housing to move forward, thereby opening the forward valve. Opening the rear valve supplies air pressure to the bolt face, thereby causing the bolt to return to its rearward position. If semi-automatic fire is selected, the limited movement of the sear trip, combined with the rearward spring-bias on the sear, causes the sear to move backwards on its pivot to a position where the sear trip can no longer apply upward pressure to the forward portion of the sear. The rear portion of the sear therefore pivots upward. The bolt will be propelled rearward to a point slightly behind the position wherein it engages the sear. As the bolt returns forward, the sear, which is no longer held in place by the sear trip, will engage the bolt, preventing further forward movement. From this position of the components, the trigger must be released before it can be pulled to fire another shot. 
   If full automatic fire at a slow cyclic rate is selected, the trigger may be pulled slightly farther to the rear before it engages the selector, thereby causing the sear trip to pivot slightly higher. Whereas the upper bearing surface of the sear trip pushes the sear up to initially release the bolt, here, the lower end bearing surface of the sear trip pushes the sear up sufficiently so that, when the bolt catches the sear, there is only about 1/32 nd  inch of engagement between the sear and bolt. The floating mass bolt is thereby momentarily held in its rearward position by the sear, which cams forward off the sear trip as the forward motion of the bolt pushes the sear from its rearward position to its forward position. 
   If full automatic fire at a high cyclic rate is selected, the trigger is allowed to travel to its maximum rearward position. The sear trip is thereby pivoted upward to its maximum extent, causing the lower end bearing surface of the sear trip to push the sear completely out of the way of the bolt. Therefore, as soon as the spring behind the bolt driver overcomes the rearward momentum of the bolt, the bolt will simply return forward and again actuate the valve. 
   A compressed gas powered gun of the present invention uses a recoil buffer system for biasing the bolt forward, and for providing a recoil for the shooter in conjunction with the floating mass bolt. A preferred buffer system includes a floating mass bolt driver, and an air resistance bolt driver, with a spring disposed there between. This assembly is located in a tube within the air gun&#39;s shoulder stock, which is preferably a cylindrical tube. The buffer assembly may be oriented so that either the air resistance bolt driver or the floating mass bolt driver is positioned directly behind the bolt, with the other bolt driver placed at the rear of the stock. The forward bolt driver will thereby abut the rear of the bolt, pushing the bolt forward. 
   If the air resistance bolt driver is positioned directly behind the bolt, light recoil results. The air resistance bolt driver has less mass than the floating mass bolt driver, resulting in less mass reciprocating back and forth. Additionally, the air resistance bolt driver will trap air behind it as it reciprocates, thereby slowing travel of the reciprocating mass. Conversely, positioning the floating mass bolt driver behind the bolt results in heavier recoil, due to the increased reciprocating mass and the lack of the ability of the floating mass bolt driver to trap air. The shooter may therefore select the desired level of recoil to correspond with the recoil of the conventional firearm the shooter wishes to simulate. 
   Some preferred embodiments of the invention will include a laser emitter structured to emit a laser substantially parallel to the path of a bullet that would have been discharged from an actual firearm upon the pulling of the trigger of the simulator. Suitable laser emitters are presently available, but have not yet been combined with firearms training simulators providing the advantages of the present invention. One preferred laser emitter assembly includes a laser emitter housed within a front sight block disposed forward of the forward hand guards, and underneath the front sight. The electronics, battery, and switch for the laser emitter may be located within the handguards, wherein they are easily reached for service. One embodiment of the switch may be a roller switch structured to be actuated by a switching rod extending forward from the bolt. When the bolt moves forward in response to pulling the trigger, the switching rod engages the roller of the switch, thereby depressing the switch and actuating the laser. Another embodiment uses a proximity switch mounted in a location wherein a magnet may be brought into contact with it upon forward movement of the bolt. A preferred location is adjacent to the juncture between a barrel and upper receiver. A magnet affixed to the bolt is structured to be brought into proximity with the proximity switch when the bolt is in its forwardmost position, thereby causing the proximity switch to actuate the laser. 
   It is therefore an object of the present invention to provide a firearms training simulator simulating the recoil of a conventional firearm. 
   It is another object of the present invention to provide a firearms training simulator wherein the level of recoil provided to the shooter may be selected by the shooter. 
   It is a further object of the present invention to provide a firearms training simulator capable of simulating the operation of a conventional firearm. 
   It is another object of the present invention to provide a firearms training simulator capable of both semi-automatic and full automatic operation. 
   It is a further object of the present invention to provide a firearms training simulator wherein different cyclic rate of full automatic fire may be utilized. 
   It is another object of the present invention to provide a firearms training simulator including a laser emitter assembly structured to emit a laser substantially along the path of a bullet that would have been discharged from an actual firearm. 
   These and other objects of the present invention will become more apparent through the following description and drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a side view of a firearms training simulator according to the present invention. 
       FIG. 2  is a partially exploded side isometric view of a firearms training simulator according to the present invention. 
       FIG. 3  is a partially exploded view of an upper receiver for a firearms training simulator according to the present invention. 
       FIG. 4  is an exploded side isometric view of a bolt for a firearm training simulator according to the present invention. 
       FIG. 5  is a side view of a buffer assembly for a firearms training simulator according to the present invention. 
       FIG. 6  is a side cutaway view of a buffer assembly for a firearms training simulator according to the present invention, showing the components configured for low recoil. 
       FIG. 7  is a side cutaway view of a buffer assembly for a firearms training simulator according to the present invention, showing the components configured for high recoil. 
       FIG. 8  is a side view of a four position selector switch for a firearms training simulator according to the present invention. 
       FIG. 9  is a side view of a four position selector switch for a firearms training simulator according to the present invention, rotated 90° from the position of  FIG. 8 . 
       FIG. 10  is an exploded side isometric view of a valve assembly for a firearms training simulator according to the present invention. 
       FIG. 11  is a side cross-sectional view of a trigger assembly, valve assembly, and bolt of a firearms training simulator according to the present invention, showing the position of the components before the trigger is pulled. 
       FIG. 12  is a side cross-sectional view of a trigger assembly, valve assembly, and bolt of a firearms training simulator according to the present invention, showing the position of the components at the moment of firing. 
       FIG. 13  is a side cross-sectional view of a trigger assembly, valve assembly, and bolt of a firearms training simulator according to the present invention, showing the position of the parts after firing with the trigger still depressed during semi-automatic fire. 
       FIG. 14  is a side cross-sectional view of a trigger assembly, valve assembly, and bolt of a firearms training simulator according to the present invention, showing the position of the components after the bolt has returned and with the trigger still pulled during full automatic fire at a slow cyclic rate. 
       FIG. 15  is a side cross-sectional view of a trigger assembly, valve assembly, and bolt of a firearms training simulator according to the present invention, showing the position of the components with the bolt retracted and trigger depressed during full automatic fire at a high cyclic rate. 
       FIG. 16  is an exploded side isometric view of a valve assembly for a firearms training simulator according to the present invention. 
       FIG. 17  is a side isometric view of the electronic components of a laser simulator for a firearms training simulator. 
       FIG. 18  is a top view of the electronic components for a laser simulator for a firearms training simulator. 
       FIG. 19  is a side view of a roller switch for a laser simulator for a firearms training simulator according to the present invention. 
       FIG. 20  is a top view of a barrel assembly, the electronics for a laser simulator assembly, and a switch activation rod for a firearms training simulator according to the present invention. 
       FIG. 21  is a front view of a laser emitter for a firearms training simulator according to the present invention. 
       FIG. 22  is an isometric top view of a barrel assembly, and laser emitter electronics for a firearms training simulator of the present invention. 
       FIG. 23  is a top view of a proximity switch for a firearms training simulator of the present invention. 
       FIG. 24  is a bottom view of a proximity switch for a firearms training simulator according to the present invention. 
       FIG. 25  is a top view of the electronics for a laser emitter for a firearms training simulator according to the present invention. 
       FIG. 26  is a side view of a magnet for use with a proximity switch within a firearms training simulator of the present invention. 
   

   Like reference characters denote like elements throughout the drawings. 
   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The present invention provides a firearms training simulator that simulates the recoil of a conventional firearm. Referring to  FIGS. 1-2 , an embodiment of the firearms training simulator representing an AR-15 or M-16 rifle is illustrated. The firearm straining simulator  10  includes a receiver  12  which in the present embodiment includes a lower receiver  14  mated to an upper receiver  16 . Like a conventional M-16, the upper receiver  16  is pivotally secured to the lower receiver  14  by a screw or pin  18  passing through corresponding apertures  20 ,  22  within the upper receiver  16  and lower receiver  14 , respectively. A captive takedown pin  24  is secured within the rear portion of the lower receiver  14 , and is structured to fit within the aperture  26  defined within the rear portion of the upper receiver  16 . The lower receiver  14  also includes a pistol grip  28 , a trigger  30  disposed in front of the pistol grip  28 , and a selector  32  disposed above the pistol grip  28 . The lower receiver  14  further includes a compressed gas inlet fitting  34  structured to receive a compressed gas hose  36  leading to a compressed gas supply. Suitable compressed gas supplies are known to those skilled in the art of air guns, and therefore not described in detail herein. 
   The upper receiver  16  is structured to receive a reciprocating bolt therein, as will be described in detail below. The upper receiver  16  is further structured to receive a charging handle  38  directly above the bolt, and structured to retract the bolt upon itself being retracted. The top of the upper receiver  16  includes a means for securing a rear sight thereon, with a preferred means being a universal sight rail  40  such as a Weaver rail. The illustrated rear sight  42  is a conventional carrying handle sight having an adjustable aperture sight mechanism  44  mounted thereon. It will be apparent to those skilled in the art that other conventional rear sights, such as folding aperture rear sights, telescopic sights, and/or illuminated dot sights or combinations thereof may be mounted to the sight rail  40 . A forward assist assembly  45  is defined within the upper receiver  16 , thereby facilitating any desired training drills utilizing a forward assist. The forward assist  45  is identical to that of a conventional AR-15 or M-16 rifle, and is therefore not further described. 
   A shoulder stock  46  is secured to the lower receiver  14 . The illustrated embodiment of a shoulder stock  46  is a collapsible, telescoping shoulder stock having a buffer tube  48  upon which a sliding shoulder piece  50  is slidably mounted, with the shoulder piece  50  being structured to be locked in place on the buffer tube by the adjustment lever  52 . 
   A barrel assembly  54  is mounted to the front portion of the upper receiver  16 . The barrel assembly  54  includes a barrel  56  which is directly secured to the upper receiver  16 . An upper handguard  58  and lower handguard  60  are secured between the nosecap  62  at their forward end and a lock ring  64  that is slidably mounted on a barrel nut assembly, which is not shown and well known to those skilled in the art. A front sight block  66  is disposed around the barrel  56  in front of the nosecap  62 . The illustrated front sight block  66  includes a top Weaver rail  68 , right side Weaver rail  70 , lower Weaver rail  72 , and left side Weaver rail  74  ( FIG. 16 ). In the illustrated embodiment, a front sight  76  is detachably mounted to the top Weaver rail  68 , and includes a post type front sight therein (not shown and well known in the art). Alternative front sights include folding front sights, or the front sight  76  may be omitted entirely if an optical or illuminated dot sight is selected. The remaining Weaver rails  70 ,  72 ,  74  may, if desired, be used to attach items such as flashlights, laser sights, bipods and/or sling swivels to the firearms training simulator  10  to bring the configuration of the firearms training simulator  10  as close as possible to the actual rifle being used by the trainee. The illustrated embodiment of the firearms training simulator  10  also includes a flash hider  78  at the muzzle end of the barrel  56 , thereby further conforming the configuration of the firearms training simulator  10  to that of an actual rifle. 
   Referring to  FIGS. 3 and 4 , the bolt  80  is slidably mounted within the channel  82  defined within the upper receiver  16 . The bolt  80  includes a tubular body  84  having a floating mass therein. A preferred floating mass includes a plurality of weights  86  separated by cushions  88 . Although 3 weights  86  are illustrated, a different number may be selected. A spring  90  for biasing the weights  86  forward is disposed between the rearmost weight  86  and an end cap  92  structured to be secured to the back end  94  of the bolt  80 . A slot  96  for receiving an O-ring  98  is defined in a forward portion  100  of the bolt  80 . Referring briefly to  FIG. 11 , the bolt  80  includes a forward gas receiving surface  102  across its entire forward face, and defines a centrally located valve actuation projection  104  on the gas receiving surface  102 . A bolt key  106  is secured to the top of the bolt  80 , in the illustrated embodiments by a pair of screws  108  passing through the apertures  110  within the bolt key  106 , and being secured within the apertures  112  defined within the body  84  of the bolt  80 . A switch actuation rod  114  may be secured to the bolt key  106  so that it extends forward of and substantially parallel to the bolt  80 , in the illustrated embodiment by the screw  116  passing through the aperture  118  defined within the bolt key  106 , and into another aperture within the rear portion  120  of the switch actuation rod  114 . A spacer  95  may be disposed in front of the forwardmost weight  86  to limit the travel of the weights  86  to that which is desired. 
   Referring to  FIGS. 5-7 , a buffer system  122  is illustrated. A preferred buffer system  122  includes an air piston bolt driver  124 , a floating mass bolt driver  126  having a floating mass  128  therein, and a spring  130  disposed therebetween. The air piston bolt driver may be made of two pieces: a forward portion  132  and a rear portion  134 . The buffer system  122  is located directly behind the bolt  80 , and is housed within the buffer tube  48 . Depending on the length of the buffer tube  48 , the forward portion  132  of the air resistance bolt driver  124  may either be attached or removed from the rear portion  134  of the air piston bolt driver  124 . 
     FIG. 6  illustrates the buffer assembly  122  configured for low recoil. The air piston bolt driver  124  is located directly behind the bolt  80 , so that it will reciprocate along with the bolt  80 . The air resistance bolt driver  124  has a low mass as compared to the floating mass bolt driver  126 , and will also trap air behind it as it reciprocates, thereby reducing the level of recoil felt by a shooter by reducing the total reciprocating mass of the bolt  80  and bolt driver  124 , and also through increased air resistance. If greater recoil is desired, the configuration of  FIG. 7 , wherein the floating mass bolt driver  126  is located behind the bolt  80 , may be selected. The high mass of the floating mass bolt driver  126  as compared with the air piston bolt driver  124 , combined with the inability of the floating mass bolt driver to trap air behind it, increases the level of recoil felt by a shooter by increasing the total mass of the bolt  80  and the bolt driver  126  that reciprocates back and forth. Additionally, the floating mass within both the bolt  80  and bolt driver  126  will continue to move rearward once the bolt  80  and floating mass bolt driver  126  have reached their maximum rearward position, further enhancing the sensation of recoil experienced by the shooter. Referring back to  FIGS. 1 to 2 , the configuration of the buffer system  122  may be easily changed by driving the pin  24  to the right, and then pivoting the upper receiver  16  with respect to the lower receiver  14  around the screw or pin  18 . The spring  130  and bolt drivers  124 ,  126  may then be removed from the buffer tube  48  and repositioned as desired. 
   Referring to  FIGS. 11 to 15 , the trigger assembly  136 , bolt  80 , and valve assembly  138  are illustrated. The trigger  30  is pivotally secured within the lower receiver  14  at pivot  140 , and is biased toward its forward position by the trigger return spring  142 . The trigger  136  includes a finger engaging portion  144 , and a selector engaging portion  146 . The selector engaging portion  146  is structured to abut a selector  32  when the trigger  30  is pulled rearward. The selector  32  is best illustrated in  FIGS. 8-9 . The selector  32  includes an actuator  148  for permitting the shooter to rotate the selector  32  as explained below, and a trigger engaging portion  150 . The trigger engaging portion  150  includes a first surface  152 , corresponding to safe. A second surface  154  of the trigger engaging portion  54  corresponds to semi-automatic fire. A third surface  156  of the trigger engaging portion  54  corresponds to full automatic fire at a slow cyclic rate. This surface  156  is different from selectors used in firearms in that it is cut to a different geometry to be used as a cam stop for the trigger as opposed to a surface that controls disconnectors. It is therefore sufficiently different that it cannot be used in a firearm. Lastly, the trigger engaging portion  54  defines a channel  158  corresponding to full automatic fire at a high cyclic rate. Referring back to  FIGS. 11 to 15 , the trigger  30  is pivotally secured to one end of a trigger bar  160 , with the other end of the trigger bar  160  secured to a sear trip  162 . The sear trip  162  includes a sear engaging end  164 , having an upper radius surface  166  and a lower radius surface  168 . The sear  170  is pivotally secured within the lower receiver  14  by a sliding pivot  172 . The sear  170  includes a front end  174 ; structured to engage the sear trip  162 , and a back end  176 , structured to mate with a notch  178  defined within the bolt  80 . A spring  180  biases the sear rearward, and the front end  174  downward. 
   Referring to  FIGS. 10 to 15 , the valve assembly  138  is illustrated. The valve assembly  138  includes a valve body  182  having a forward valve  184  and rear valve  186  therein, with the forward valve  184  and rear valve  186  being separated and biased away from each other by the spring  188 . In the illustrated embodiment, the forward valve  184  and rear valve  186  each include a stop  190 , with a plunger  192  extending outwardly therefrom. A seal  194  is retained on the stop  190  by the plunger  192 . A forward bushing  196  is retained within the forward portion of the valve body  182  by a retaining ring  198 . The forward bushing  196  defines a circumferential groove  200  for securing the O-ring  202  therein. Likewise, a rear bushing  204  is secured within the rear portion of the valve body  182  by a retaining ring  206 . The rear bushing  204  defines a circumferential groove  208  for securing an O-ring  210  therein. A preferred valve assembly  138  is a captive assembly, which in the illustrated embodiment includes a housing  212  fitting over the body  182 , with the body  182  secured within the housing  212  by a pin  214  fitting within the hole  216  defined within the housing  212 . The valve assembly  138  is therefore secured together by the interaction of the retaining ring  206  and the valve body  182  at its back end, and by the interaction of the retaining ring  198  and the housing  212  at its forward end. A compressed gas inlet fitting  218  is secured within the housing  212 , and is in communication with a source of compressed gas. 
   In use, the front rear valve  184  will be stationary. The unit formed by the housing  212  and body  182  reciprocates between a forward position and a rearward position, with the seal  194  of the forward valve  184  bearing against the bushing  196  to close the front valve  184  when the body  182 /housing  212  are in their rearward position, and with the seal  194  being separated from the bushing  196  when the housing  212  and body  182  are in their forward position. The rear valve  186  reciprocates within the body  182 . In the rearward position of the valve  186 , the seal  194  is pressed against the bushing  204 , closing the rear valve  186 . When the rear valve  186  moves forward, the seal  194  is separated from the bushing  204 , thereby opening the rear valve. 
   Referring to  FIG. 16 , the barrel assembly  54  is illustrated in greater detail. The various components of the laser emitter assembly are located within the barrel assembly  54 . Many components of a preferred laser emitter assembly are available from Laser Shot, located in Stafford, Tex. Referring to  FIGS. 16 to 18 , the laser emitter assembly includes a circuit board  220 , a battery box  222 , a switch  224 , and a laser emitter  226 . The laser emitter  226  is preferably housed within the front sight block  66 , and is oriented to emit a laser beam substantially parallel to the barrel  56 . The remaining components are housed between the upper handguard  58  and lower handguard  60 , where they are well protected and easily serviced by retracting the lock ring  64 , and removing the handguards  58 ,  60 . The circuit board  220  and battery box  222  are mounted directly to the barrel  56 . A pair of wires  228  supply the circuit board  220  with electrical power from the batteries contained within the battery box  222 . A pair of wires  223  ( FIG. 25 ) carries electrical power from the circuit board  220  to the laser emitter  226 . A switch  224  is also mounted to the barrel  56 , in the illustrated embodiment by being secured to a front clamp  230 , which is itself secured to the barrel  56 . The switch  224  is best illustrated in  FIG. 19 . The illustrated embodiment of the switch  224  is a roller switch, having a body  232  with a switch on  234  extending therefrom. A roller  236  is rotatably mounted at the end of the switch on  234 . A button  238  protrudes from the switch body  232 , abutting the switch on  234 , so that depressing the switch on  234  also depresses the button  238 . The body  232  of the switch  224  is electrically connected to the circuit board  220  by the wires  240 . 
   The barrel assembly  54  also includes a rear clamp  242 , having a barrel aperture  244  for securing the clamp  242  around the barrel  56 , and a switch activation rod guide aperture  246  structured to receive and guide the switch activation rod  114  as it reciprocates with the bolt, so that the switch activation rod  114  will engage the roller  236  and depress the switch on  234  when the bolt  80  is in its forward position, as illustrated in  FIG. 20 . The circuit board  220  is structured to transmit a momentary electrical current to the laser emitter  226 , thereby causing the laser emitter  226  to emit a laser beam of brief duration, in a manner that is well known to those skilled in the art. 
   An alternative switching mechanism is illustrated in  FIGS. 22 to 26 . The remainder of the laser emitter assembly within these figures uses the same circuit board  220 , battery box  222 , and laser emitter  226  as the previously described embodiments. However, the roller switch  224  has been replaced with a proximity switch  248  mounted adjacent to the breach end  250  of the barrel  56 , and passing through the lock ring  64  into the upper receiver  16 . The bolt key  106  has a magnet  252  secured within the aperture  118 , where it replaces the switch activation rod  114 . When the bolt  80  is in its forward position, the magnet  252  is brought sufficiently close to the proximity switch  248  to trip the proximity switch  248 . 
   To use the firearms training simulator  10 , a supply of compressed gas is connected to the fitting  34 . The gas selected may either be compressed air, or any compressed gas commonly used for air guns, for example, carbon dioxide. Compressed air will be supplied to the fitting tube  218  of the valve assembly  138 , between the forward valve  184  and rear valve  186 . Before firing, the trigger mechanism  136 , valve assembly  138 , and bolt  80  are in the positions illustrated in  FIG. 11 . The bolt  80 , although biased forward by pressure from the spring  130 , is held in its rear position by the rear end  176  of the sear  170  engaging the notch  178 . Pressure from the spring  180  holds the sear  170  in this position. Forward pressure from the bolt  80  against the sear  70  pushes the sear towards its forwardmost position on the sliding pivot  172 . The trigger spring  142  holds the trigger  30  in its forwardmost position. The selector  32  may be rotated to the appropriate position, corresponding to safe, semi-automatic, or full automatic at a low or high cyclic rate. 
     FIG. 12  depicts the location of the parts when the trigger is pulled. Trigger  30  has been pulled rearward until the selector engaging portion  146  engages the surface  154 ,  156 , or channel  158  of the selector  32 . The trigger bar  160  has moved rearward, thereby pivoting the end  164  of the sear trip  162  upward so that the radiused surface  166  pushes the sear&#39;s forward end  174  upward, thereby pivoting the sear&#39;s back end  176  downward, releasing the bolt  80  to travel forward. When the bolt  80  reaches its forwardmost position, air pressure between the bolt  80  and valve body  182  causes the valve body  182  to move forward, thereby opening the forward valve  184 . At the same time, the bolt  80  strikes the plunger  192  of the rear valve  186 , thereby moving the rear valve  186  forward to open the rear valve  186 , thereby releasing compressed air to the bolt  80 . At the same time, depending upon the embodiment selected, either the switch activation rod  114  has engaged and depressed the roller  236  of the switch on  234 , thereby tripping the switch  224 , or alternatively the magnet  252  has been brought into proximity with the proximity switch  248 , thereby triggering the circuit board  220  to signal the laser emitter  226  to emit a laser. The bolt  80  is then pushed to its rearward position by the compressed air released from the rear valve  186 , as the pressure from the compressed air overcomes the bias of the spring  130 . 
     FIG. 13  depicts the location of the components after firing a shot in semi-automatic mode, with the trigger still depressed. The spring  180  has pulled the sear  170  to the rear, where the end  174  slips off the radiused surface  166 , permitting the sear to rotate so that the rear end  176  rotates upward. The bolt  80  is retracted to a position slightly behind the point where the notch  178  engages the sear  170 . As the bolt  80  returns forward under pressure from the spring  130 , the notch  178  and sear  176  engage each other, thereby arresting forward travel of the bolt  80 . At this point, releasing the trigger  30  is necessary to fire another shot. 
     FIG. 14  depicts the position of the parts when the firearms training stimulator  10  is discharged in full automatic mode at a slow rate of fire. In this mode of operation, the selector  32  is rotated so that the surface  156  engages the selector engaging portion  146  of the trigger  30 . The trigger  30  is thereby permitted to move back farther than in semi-automatic mode, wherein the surface  154  was engaged. As before, gas pressure forces the bolt  80  back to a position slightly behind the point wherein it engages the sear  170 . The sear trip  162  is thereby rotated slightly higher, so that the lower radius  168  pushes upward on the front end  174  of the sear  170 . The sear  170  is pulled towards its rearmost position on the sliding pivot  172  by the spring  180 , and is thereby also pulled so that the rear end  176  of the sear  170  is rotated upward. As the bolt  80  returns forward under pressure from spring  130 , about 1/32 inch of the rear end  176  of the sear  170  catches the notch  178  of the bolt  80 . The floating mass  86 , which at this point will be located in the rear portion of the bolt  80 , has slowed the bolt  80  sufficiently so that it will momentarily catch on the sear  170 . When the bolt  80  engages the sear  170 , forward pressure applied to the sear  170  by the bolt  80  will cause the sear  170  to cam off the radiused surface  166  as it moves towards its forwardmost position on a sliding pivot  172 , rotating the sear  170  out of the path of the bolt  80 . The bolt  80  is then free to travel forward to discharge another shot. 
     FIG. 15  depicts the location of the parts if full automatic fire at a high cyclic rate is selected. The selector  32  is rotated so that the selector engaging portion  146  of the trigger  30  corresponds to the channel  158  within the selector  32 , permitting the trigger  30  to travel to its maximum rearward position. The sear trip  162  is thereby rotated to its maximum upward position, thereby rotating the sear  170  completely out of the way of the bolt  80 . When the bolt  80  travels rearward sufficiently for the spring  130  to overcome the air pressure from the valve  186 , there is nothing to impede the forward motion of the bolt  80 . This results in a maximum cyclic rate. 
   A typical cyclic rate for full automatic fire with a low cyclic rate is approximately 600 rounds per minute. A typical cyclic rate for full automatic fire at a high cyclic rate is approximately 900 rounds per minute, approximately simulating the cyclic rate of an M-16 rifle. 
   If desired, the lower receiver assembly  14  and components therein of the firearm training simulator  10  of the present invention may be mated with an upper receiver assembly and barrel assembly of an air gun as disclosed in U.S. patent application Ser. No. 09/756,891, from which this application is a continuation-in-part. The trainee therefore has the option of training using either a laser simulator or an air gun merely by mounting the appropriate upper receiver and barrel assembly on the same lower receiver assembly. The upper and lower receiver assemblies  14 ,  16 , may be detached from one another by first driving the takedown pin  24  to its rightmost position, and then removing the screw or pin  18 . Those skilled in the art will recognize that this is the same method of removing the upper assembly from the lower assembly of a conventional M-16 or AR-15 rifle. 
   The firearms training simulator therefore simulates the recoil, cyclic rate, configuration, controls, and mode of operation of the firearm for which it is intended to be used to train a shooter. The training simulator therefore provides the opportunity to conduct decision-making training scenarios projected on a screen, with the safety and reduced facilities cost of using a laser instead of live ammunition, while duplicating a sufficient number of the characteristics of a conventional firearm so that the training will effectively carry over to a conventional firearm. 
   While a specific embodiment of the invention has been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the invention which is to be given the full breadth of the appended claims and any and all equivalence thereof.