Patent Publication Number: US-9835403-B2

Title: Connector for toy gun

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to and the benefit of Korean Patent Application No. 2015-0183021, filed on Dec. 21, 2015 and Korean Patent Application No. 2016-0042936, filed on Apr. 7, 2016, the disclosure of which is incorporated herein by reference in its entirety. 
     BACKGROUND 
     1. Field of the Invention 
     The present invention relates to a connector for a toy gun, and more particularly, to a connector capable of controlling cocking of a toy gun, depending on whether or not a projectile remains in the toy gun. 
     2. Discussion of Related Art 
     As societies develop, people have come to enjoy diverse leisure activities for reasons such as health, hobbies, and the like, and leisure activity population is also gradually increasing. Among the diverse leisure activities, survival games are gradually growing in developed countries in terms of participating population as well as market size. In the case of such a survival game, mock allied forces and mock enemy forces play a survival game using a toy gun in a shape similar to a real gun and thereby promoting health, stress reduction, friendship, realistic military training, and the like. 
     Specifically, in the case of a conventional toy gun for a survival game, a projectile such as a BB pellet supplied from a magazine and positioned at front end of a cylinder is fired when a piston moved back in the cylinder suddenly thrusts forward by force of compressed air or a spring. 
     In the case of the conventional toy gun for a survival game described above, with the cylinder fixed, only the piston reciprocates forward and backward to fire the projectile. In addition, a rack gear portion is formed outside of the piston, a gear train connected to the rack gear portion by gear engagement is driven by an electric motor, and thereby the piston is automatically moved to a position (a moved back position) ready for firing. 
     Meanwhile, in the case of the conventional toy gun for a survival game described above, when damage occurs to a gear due to repetitive use impacts malfunction, etc., there arises a problem in which the whole piston assembly needs to be replaced because the piston and the rack gear portion are integrally formed. In addition, such a piston is formed of an expensive metal material, resulting in much of financial burden put on a user. 
     In addition, in the case of the conventional toy gun, a user cannot determine whether or not a projectile remains, and therefore a piston is unnecessarily reciprocated by cocking by a user even when there is no projectile. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to providing a connector for a toy gun capable of sensing whether or not a projectile remains in the toy gun. 
     In addition, the present invention is directed to providing a connector for a toy gun capable of controlling cocking of a toy gun, depending on whether or not a projectile remains in the toy gun. 
     The technical objectives of the present invention are not limited to the above objects, and other objectives not described herein may become apparent to those of ordinary skill in the art based on the following description. 
     According to an aspect of the present invention, there is provided a connector for a toy gun, including: a connector body coupled to the toy gun to be connected with an upper portion of a magazine when the magazine is inserted into the toy gun; a hole formed to pass through front end of the connector body and configured to accommodate a projectile provided by the magazine; a projectile fixing portion positioned on the connector body in which the hole is formed and configured to fix the projectile provided via the hole; a projectile sensing portion which senses whether or not a projectile remains in the hole; and a first protrusion interlocked with the projectile sensing portion to control a movement of a cylinder of the toy gun depending on whether or not a projectile remains in the hole. 
     According to another aspect of the present invention, there is provided a connector for a toy gun, including: a connector body coupled to the toy gun to be connected with an upper portion of a magazine when the magazine is inserted into the toy gun; a hole formed to pass through front end of the connector body and configured to accommodate a projectile provided by the magazine; a projectile fixing portion positioned on the connector body in which the hole is formed and configured to fix the projectile provided via the hole; a projectile sensing portion whose position changes in the connector body depending on whether or not a projectile remains in the hole; and a first protrusion allowed to rotate by the projectile sensing portion depending on whether or not a projectile remains in the hole and configured to rotate by pressure of a stopper which controls a movement of a cylinder in the toy gun. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objects, features and advantages of the present invention will become more apparent to those of ordinary skill in the art by describing in detail exemplary embodiments thereof with reference to the accompanying drawings, in which: 
         FIG. 1  is a schematic configuration view of a toy gun according to a first embodiment of the present invention; 
         FIG. 2  is a view illustrating a magazine and a connector according to the first embodiment of the present invention; 
         FIG. 3  is a detailed view illustrating a connector according to the first embodiment of the present invention; 
         FIGS. 4A and 4B  illustrate a connector of the first embodiment, in which there is a remaining projectile; 
         FIGS. 5A and 5B  illustrate a connector of the first embodiment, in which there is no projectile; 
         FIG. 6  is a detailed view illustrating a toy gun according to the first embodiment of the present invention; 
         FIGS. 7 and 8  are detailed views illustrating a cylinder assembly of a toy gun according to the first embodiment of the present invention; 
         FIG. 9  is a view illustrating a state in which a cylinder and a piston of a toy gun are moved back according to the first embodiment of the present invention; 
         FIG. 10  is a view illustrating a state in which a cylinder of a toy gun is moved forward (in a state ready to fire) according to the first embodiment of the present invention; 
         FIG. 11  is a view illustrating a process in which a piston of a toy gun moves forward according to the first embodiment of the present invention; 
         FIG. 12  is a diagram illustrating a driving control mechanism of a toy gun according to the first embodiment of the present invention; 
         FIG. 13  is a schematic configuration view of a toy gun according to a second embodiment of the present invention; 
         FIG. 14  is a view illustrating a magazine and a connector according to the second embodiment of the present invention; 
         FIG. 15  is a detailed view illustrating a connector according to the second embodiment of the present invention; 
         FIGS. 16A and 16B  illustrate a connector of the second embodiment in which there is a remaining projectile; and 
         FIGS. 17A and 17B  illustrate a connector of the second embodiment in which there is no projectile. 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     The objects, features, and advantages described above will become more apparent from the following detailed description of the embodiments of the present invention with reference to the accompanying drawings, and thereby those skilled in the art may easily implement the technical spirit of the present invention. In the following description, detailed descriptions of well-known technologies will be omitted where they may unnecessarily obscure the subject matters of the present invention. 
     First Embodiment 
     Hereinafter, a toy gun will be described in detail according to a first embodiment of the present invention and with reference to the accompanying drawings. 
     Referring to  FIG. 1 , a toy gun  100  according to the first embodiment of the present invention includes a magazine  20 , a connector  30 , a toy gun main body  110  having a cartridge chamber into which a projectile  10  supplied from the connector  30  is individually loaded, a cylinder assembly  120 , a piston  130 , and a driving control mechanism  200 . 
     As illustrated in  FIG. 2 , as an example, the magazine  20  includes a magazine body  21 , a storage space  22 , a feed tube  23 , a feed wheel  24 , a protrusion  25 , an elastic body  26 , an outlet  27 , and an insertion port  28 . 
     The magazine body  21  is formed in a size and shape that allows detachable installation on the toy gun  100 , and the storage space  22  is a space for storing the projectile  10 . In addition, the feed tube  23  is disposed inside the magazine body  21  and is formed in a tube shape to move the projectile  10  upward. The feed wheel  24  is disposed at a lower portion inside the magazine body  21 , and the protrusion  25  is formed in a sawtooth shape on a perimeter of the feed wheel  24  so that the projectile  10  is individually supported. The projectiles  10  are supplied to the feed tube  23  by rotation of the feed wheel  24 . In addition, the elastic body  26  is disposed inside the feed wheel  24  and is formed as a clockwork spring to provide elasticity for rotating the feed wheel  24 . The outlet  27  is formed at an upper portion of the magazine body  21  to discharge the projectile  10  to the outside, and the insertion port  28  also is formed at the upper portion of the magazine body  21  and is configured to be openable and closable for replenishing the projectile  10  into the storage space  22 . 
     As illustrated in  FIG. 3 , the connector  30  includes a connector body  31 , a hole  32 , a projectile fixing portion  33 , a projectile sensing portion  34 , a first protrusion  35 , a second protrusion  36 , and a cylindrical entrance  37 . The connector  30  may be fixed inside the toy gun main body  110  or inserted into the toy gun main body  110  along with the magazine  20  when the magazine  20  is inserted into the toy gun main body  110 . The present embodiment describes the connector  30  fixed inside the toy gun main body  110 . 
     When the magazine  20  is inserted into the toy gun main body  110 , the connector body  31  is coupled to the toy gun main body  110  to be connected to an upper portion of the magazine  20 . 
     The hole  32  is formed to pass through front end of the connector body  31  and configured to accommodate the projectile  10  provided by the magazine  20 . The hole  32  has a greater diameter than the projectile  10  so that the projectile  10  may pass therethrough. 
     The projectile fixing portion  33  is formed on the connector body  31  at which the hole  32  is formed and includes right and left side walls  33   a  for fixing the projectile  10  provided via the hole  32  and an aisle  33   b  between the right and left side walls  33   a  so that the projectile  10  moves to the cartridge chamber by pressure from the cylinder assembly  120 . Each of the right and left side walls  33   a  includes grooves  33   c  which may accommodate and fix the projectile  10  at inside surfaces thereof. 
     The projectile sensing portion  34  is for sensing whether or not a projectile  10  remains in the magazine  20  and the hole  32  and includes a plate  34   a  inserted into the connector body  31  and a spring  34   b  which pushes the plate  34   a  toward the hole  32 . When there is no projectile in the hole  32 , the plate  34   a  is inserted into the hole  32  through a side surface of the hole  32 , and conversely when there is a remaining projectile  10  in the hole  32 , the plate  34   a  is positioned outside of the hole  32  because the plate  34   a  is not allowed to be inserted into the hole  32  due to a remaining projectile  10 . Therefore, whether or not a projectile remains in the hole  32  may be determined depending on a position of the plate  34   a . In addition, front end of the plate  34   a  is formed to have a slope so that a lower surface is longer than an upper surface for easily pushing up the remaining projectile  10  toward projectile fixing portion  33 . The projectile sensing portion  34  is positioned between the hole  32  and the first protrusion  35 . 
     The first protrusion  35  is inserted into rear end of the connector body  31  to be vertically rotatable about a first rotating shaft  35   a  and is provided with rotating force by a spring  35   b  positioned thereunder. The first protrusion  35  is interlocked with the projectile sensing portion  34  to rotate depending on whether or not a projectile remains in the hole  32 , and the first protrusion  35  controls a movement of a cylinder  121  of the toy gun  100  by the rotation. For example, when there is a remaining projectile  10  in the hole  32  as illustrated in  FIGS. 4A and 4B , the plate  34   a  lays down and fixes the first protrusion  35 . Accordingly, the first protrusion  35  allows the cylinder  121  to pass the connector  30  and move toward the projectile fixing portion  33 . Conversely, when there is no projectile in the hole  32  as illustrated in  FIGS. 5A and 5B , the plate  34   a  and the first protrusion  35  become spaced apart from each other as the plate  34   a  moves toward the hole  32 , and thereby the first protrusion  35  rotates upward. That is, the first protrusion  35  is allowed to rotate by the plate  34   a  and rotates by the spring  35   b . Therefore, the first protrusion  35  blocks the cylinder  121  from moving toward the projectile fixing portion  33 . Here, although the first protrusion  35  itself may be formed to control movement of the cylinder  121  by vertical rotation, the first protrusion  35  controls the movement of the cylinder  121  in the present embodiment by vertically moving a stopper  300  that is to be described below. 
     The second protrusion  36  is formed at a side surface of the plate  34   a  to be rotatable about a second rotating shaft  36   a  and is formed to be interlocked with the projectile sensing portion  34  to protrude from a surface of the connector body  31  depending on whether or not a projectile remains in the hole  32 . For example, when there is a remaining projectile  10  in the hole  32  as illustrated in  FIGS. 4A and 4B , the plate  34   a  lays down and fixes the second protrusion  36 , and accordingly, the second protrusion  36  remains inserted in the connector body  31 . In addition, while a remaining projectile  10  in the hole  32  moves toward the projectile fixing portion  33 , the second protrusion  36  remains inserted in the connector body  31  due to pressure of a lower portion of the cylinder  121 . Conversely, when there is no projectile in the hole  32  as illustrated in  FIGS. 5A and 5B , the second protrusion  36  protrudes from the surface of the connector body  31 , as the plate  34   a  moves toward the hole  32 . After this, when the cylinder  121  moves toward the projectile fixing portion  33 , the second protrusion  36  is inserted into the connector body  31  again due to the pressure of a lower portion of the cylinder  121 , and the plate  34   a  escapes out of the hole  32  by rotation of the second protrusion  36 . 
     The cylindrical entrance  37  is formed under the hole  32  to connect the outlet  27  of the magazine  20  and the hole  32 . The cylindrical entrance  37  is formed to be provided with the projectile  10  from the outlet  27  of the magazine  20  and has a greater diameter than the projectile  10  so that the projectile  10  passes therethrough. 
     The toy gun main body  110  includes a barrel portion  111 , a handgrip  113  connected to a lower portion of the barrel portion  111 , and a cartridge chamber  115  provided at front end of the barrel portion  111 . The cylinder assembly  120  and the piston  130  are installed to reciprocate in the barrel portion  111 . 
     A power supply unit  210  and a driving motor  220  of the driving control mechanism  200  may be built in the handgrip  113 . 
     A projectile  10  (may be a BB pellet or a combined BB pellet and pellet-shell) is individually supplied and loaded into the cartridge chamber  115 . The cartridge chamber  115  is formed to receive the projectile  10  from the projectile fixing portion  33 . The magazine  20  is coupled to the toy gun main body  110  through a magazine coupling portion  117 . 
     The projectile  10  may include a configuration of a normal BB pellet combined to front end of a pellet-shell and also include only a normal BB pellet. The projectile  10  passes the outlet  27  of the magazine  20  and is individually supplied to the cartridge chamber  115  via the projectile fixing portion  33 . 
     The cylinder assembly  120  is formed to reciprocate in the barrel portion  111 . As illustrated in  FIG. 6 , the cylinder assembly  120  includes the cylinder  121 , a rack gear portion  123  detachably installed at the cylinder  121 , and a guide portion  124 . 
     As illustrated in  FIGS. 7 and 8 , the cylinder  121  includes a cylinder body  121   a  in a cylindrical shape, a cylinder head  122  inserted into front end of the cylinder body  121   a , a spring  121   b  positioned between the cylinder body  121   a  and the cylinder head  122  to space the cylinder head  122  from the cylinder body  121   a , a nozzle  121   c  inserted into the cylinder head  122  to pass through the cylinder head  122 , and a stopper  121   d  for preventing separation between the cylinder body  121   a  and the cylinder head  122 . 
     The cylinder  121  is formed to reciprocate (moving backward and moving forward) in the toy gun main body  110  to be ready for firing, and no structure (for example, a side surface guider for the cylinder.) exists between left and right side surfaces of the cylinder  121  and left and right inside surfaces of the toy gun main body  110  so that the left and right side surfaces of the cylinder  121  face the left and right inside surfaces of the toy gun main body  110  at the closest possible distance. In this case, a sense of reality may be increased because a user may feel and visually check the reciprocating actions of the cylinder  121  like a real gun. In addition, capacity of the cylinder  121  may be maximized and thus amount of compressed air generated by the cylinder  121  may be maximized because no other structure exists, such as a side surface guider. 
     The spring  121   b  provides elasticity that pushes the cylinder head  122  from the cylinder body  121   a , thereby mitigating a physical impact occurring when the cylinder  121  moves forward and collides with the toy gun main body  110 . In addition, when the cylinder  121  moves backward due to recoil after the collision, the spring  121   b  pushes the cylinder head  122  forward, and thereby the seal of the cartridge chamber  115  may be maintained. 
     Since the nozzle  121   c  has a smaller diameter than the spring  121   b , the nozzle  121   c  is inserted not only into the cylinder head  122  but also into the spring  121   b . In addition, a front end portion of the nozzle  121   c  protrudes forward from the cylinder head  122  to discharge high pressure air, and rear end of the nozzle  121   c  is inserted into front end of the cylinder body  121   a.    
     The stopper  121   d  passes through a hole formed at one side surface of the cylinder body  121   a  and inserted into a groove formed at a side surface of the cylinder head  122  corresponding to the one side surface of the cylinder body  121   a.    
     The rack gear portion  123  is formed under the cylinder  121  with a length corresponding to the length of the cylinder body  121   a . Unlike the cylinder body  121   a , the rack gear portion  123  may be formed of a nonmetal material or may also be formed of a metal material. 
     The rack gear portion  123  includes a rack gear tooth  123   c  formed at a lower surface and in a length direction of the rack gear portion  123 . In addition, the rack gear portion  123  includes a contact surface  123   a  in contact with a first sensor  281  of a sensing unit  280  and a groove  123   b  formed in a length direction of the rack gear portion  123  not to be in contact with the first sensor  281 . The contact surface  123   a  and the groove  123   b  are positioned at a lower surface of the rack gear portion  123  and next to the rack gear tooth  123   c.    
     The rack gear portion  123  is separately provided by the cylinder body  121   a  and is formed to be assembled and separated by a bolt or the like so that the rack gear portion  123  may be replaced with a new one in the case that the rack gear tooth  123   c  of the rack gear portion  123  does not work normally due to damage or breakage when used for a long time. That is, only the rack gear portion  123  may be replaced unlike the conventional method in which the whole expensive cylinder assembly  120  needs to be replaced and thereby having an advantage of reducing cost. Specifically, since the cylinder body  121   a  normally is made of expensive brass to prevent deformation while maintaining certain solidity and to reduce weight, the configuration provided with the separate rack gear portion  123  to be coupled instead of integrally manufacturing the rack gear and the expensive cylinder body  121   a  provides an advantage of not only reducing an financial burden for a user but also reducing waste of resources. 
     In addition, the rack gear portion  123  guides the reciprocating action of the cylinder assembly  120  in the toy gun main body  110  without contact between the surfaces of the cylinder  121  and the inside surfaces of the toy gun main body  110 . Since the rack gear portion  123  does not bring the surfaces of the cylinder  121  into contact with the inside surfaces of the toy gun main body  110 , the rack gear portion  123  can reduce the frictional resistance of the cylinder assembly  120 . 
     The guide portion  124  is formed on the cylinder body  121   a  and stably guides the reciprocating action of the cylinder assembly  120  along with the rack gear portion  123 . A return spring  125  is connected to the guide portion  124  to return the cylinder assembly  120  to an initial position from a state in which the cylinder assembly  120  is moved back. The guide portion  124  may be made of a nonmetal material such as a plastic or the like or may also be made of a metal material. 
     The piston  130  is installed to reciprocate in the cylinder body  121   a , moves backward along with the cylinder  121  when the cylinder  121  moves backward as illustrated in  FIG. 9 , and is locked by a locking member  250  of the driving control mechanism  200  to maintain a state ready to fire. After this, only the cylinder assembly  120  separately moves forward as illustrated in  FIG. 10 . 
     A locking portion  131  coupled to and locked by the locking member  250  of the driving control mechanism  200  is formed at an outer side of the piston  130 . The locking portion  131  may be variously implemented in a shape of a hooked jaw, a hole, or the like. Therefore, with the piston  130  is completely moved back to be in a state ready to fire, the locking portion  131  is hooked by a locking protrusion  251  of the locking member  250  to maintain the state ready to fire. In addition, when the locking is released by the locking member  250 , the piston  130  enters the cylinder  121  by an elastic force of a main spring  140  installed at rear of the piston  130 , and thereby compressed air at high pressure is provided to the nozzle  121   c  to fire the projectile  10 . Here, the main spring  140  is installed at the rear of the piston  130  inside the barrel portion  111 , is compressed by the piston  130  moving backward, launches the piston  130  into the cylinder body  121   a  by the elastic force when a lock by the locking member  250  is released, and thereby the projectile  10  may be fired using the air at high pressure. 
     The cylinder assembly  120  with the configuration described above moves forward by spring restoring force of the return spring  125  when the rack gear tooth  123   c  is separated from a cam gear  230  with the cylinder assembly  120  is moved back along with the piston  130 . In addition, the projectile  10  supplied to the cartridge chamber  115  may be positioned in front of the cylinder head  122  when the cylinder assembly  120  is moved backward. 
     As illustrated in  FIGS. 1 and 12 , the driving control mechanism  200  includes a driving unit  201 , the power supply unit  210 , the driving motor  220 , the sensing unit  280 , a control unit  286 , and a stopper  300 . 
     The driving unit  201  includes the cam gear  230 , a gear train  240 , the locking member  250 , a release lever  260 , a trigger  270 , etc. The cam gear  230  includes a gear tooth  231   a  formed at a portion of an outer circumference of the cam gear  230  to selectively engage with the rack gear tooth  123   c  of the rack gear portion  123  to move the cylinder  121  backward using power generated by the driving motor  220 . 
     In addition, as illustrated in  FIG. 6 , the cam gear  230  includes a cam gear body  231 , a cam portion  232  eccentrically installed at the rotating center of the cam gear body  231 , and a driven gear  233  which receives power from the gear train  240 . The cam gear  230  with the configuration described above rotates by receiving the power of the driving motor  220  via the gear train  240 . In the state of  FIG. 6 , the gear tooth  231   a  is connected and interlocked with the rack gear tooth  123   c  when the cam gear  230  makes one rotation, and thereby the cylinder assembly  120  moves backward along with the piston  130 . Here, it is preferable that the number of the gear tooth  231   a  be the same as the number of the rack gear tooth  123   c  so that the backward movement of the cylinder  121  is completed by the one rotation of the cam gear  230 . 
     When the cylinder assembly  120  and the piston  130  are completely moved back, the piston  130  is hooked by the locking member  250  to maintain being moved back (a state ready to fire), and the cylinder assembly  120  moves forward by an elastic restoring force of the return spring  125  when the gear tooth  231   a  of the cam gear  230  and the rack gear tooth  123   c  become separated. 
     The gear train  240  is for decelerating power of a driving gear  221  installed at the shaft of the driving motor  220  and transferring the power to the driven gear  233  of the cam gear  230 , and since diverse examples are available and the present invention is not limited by technical configurations of the gear train, detailed descriptions thereof will be omitted. 
     One end of the locking member  250  is rotatably installed in the toy gun main body  110  and the other end is connected to the release lever  260  to be interlocked. The locking member  250  described above includes the locking protrusion  251  coupled and locked to the locking portion  131  of the piston  130  moved back, as illustrated in  FIG. 9 . 
     As an example, the release lever  260  is rotatably installed in the toy gun main body  110  and includes an interlocking bar  261  which extends in one direction from the center of rotation and is connected to the other end of the locking member  250  and an interference bar  262  which extends in a direction opposite the interlocking bar  261  from the center of rotation. The interference bar  262  is a portion interfered by the cam portion  232  when the cam gear  230  rotates, and when the cam portion  232  moves from the state of  FIG. 10  to the state of  FIG. 11 , the interference bar  262  rotates by the cam portion  232  to be the state of  FIG. 11 . Then, the release lever  260  rotates, the locking member  250  connected to the release lever  260  also rotates in conjunction therewith, the locking protrusion  251  is separated from the piston  130 , and thereby the piston  130  may be launched. Although not shown in the drawings, the interference bar  262  may be formed in a shape extending toward an upper portion of the sensing unit  280 , the interference bar  262  moves toward the upper portion of the sensing unit  280  when cocking the toy gun, and the movement of the interference bar  262  may be detectable by the sensing unit  280 . Here, the term “cocking” refers to a movement of the piston  130  into the cylinder  121  to fire the projectile  10 . 
     The trigger  270  is installed so that a portion thereof is exposed outward from the toy gun main body  110  and is rotatably installed. By pulling the trigger  270 , the sensing unit  280  senses the signal and the projectile  10  is fired. 
     The power supply unit  210  includes a battery installed inside the toy gun main body  110 , and either a rechargeable battery or a normal battery may be used for the battery. 
     The driving motor  220  may be installed inside the handgrip  113  of the toy gun main body  110  and operates by receiving power from the power supply unit  210 . 
     The sensing unit  280  includes the first sensor  281  for sensing a position of the cylinder  121 , a second sensor  282  for sensing motion of pulling the trigger, and a third sensor  283  for sensing the number of times firing occurred. 
     The first sensor  281  is positioned on a moving path of the rack gear portion  123  and senses the position of the cylinder  121  by being in contact with the rack gear portion  123 . When the first sensor  281  comes in contact with the contact surface  123   a  positioned behind the groove  123   b , the control unit  286  determines that the cylinder  121  starts to move backward and the cartridge chamber  115  is open. After this, since the first sensor  281  is inserted into the groove  123   b  during the backward movement of the cylinder  121 , the first sensor  281  is not in contact with the rack gear portion  123  and thereby the control unit  286  determines that the cylinder  121  is in a process of moving backward. In addition, when the first sensor  281  is not in contact with the rack gear portion  123  after the first sensor  281  comes in contact with the contact surface  123   a  positioned in front of the groove  123   b , the control unit  286  determines that the cylinder  121  completed the backward movement. That is, the control unit  286  may determine the position of the cylinder  121  and whether or not the backward movement of the cylinder  121  is completed depending on whether or not the first sensor  281  is in contact with the rack gear portion  123 . In the same manner, the control unit  286  may determine the position of the cylinder  121  and whether or not a forward movement of the cylinder  121  is completed by using the first sensor  281  when the cylinder  121  moves forward. 
     In addition, the control unit  286  controls power supplied to the driving unit  201  depending on the position and the completion state of the backward and forward movement of the cylinder  121 , that is, depending on whether or not the cylinder  121  has returned back to the initial position. For example, when the cylinder  121  stops during the movement before completing the backward and forward movement, the control unit  286  controls the power supply unit  210  to cut the power supplied to the driving unit  201 . When the cam gear  230  rotates again in a state in which the cylinder  121  has not returned back to the initial position, the cylinder  121  collides with rear end of the toy gun main body  110 , the cam gear  230  and the rack gear portion  123  continue to engage and run even though the cylinder  121  cannot move backward any more, and thereby the cylinder  121 , the cam gear  230 , the rack gear portion  123 , and the like may be damaged. For the reason described above, the control unit  286  controls the power supply unit  210  to cut the power supplied to the driving unit  201 . 
     The second sensor  282  is for sensing motion of pulling the trigger  270  by being in contact with the trigger  270 . It is preferable that the second sensor  282  be installed on a control board inside the toy gun main body  110  and be a switching sensor which generates on/off switching signal. 
     The third sensor  283  may sense a release motion of the locking members  250  and occurrence of the cocking by being in contact with the interference bar  262 , and the control unit  286  may count the number of the cocking occurred using the third sensor  283  and store the number of the cocking occurred in a memory (not shown). The third sensor  283  is used for sensing the number of times cocking actually occurred (the number of forward movements of the cylinder). 
     In addition, although not illustrated in the drawings, a fourth sensor for sensing loading and unloading of the magazine  20  may be further included. 
     The control unit  286  not only controls an operation of the driving motor  220  according to each sensed signal from first to third sensors  281 ,  282 ,  283  and the fourth sensor but also controls the power supply unit  210  to selectively cut or allow a power supply to the driving motor  220 . 
     The stopper  300  is formed on a movement path of the cylinder  121  in the barrel portion  111  to block the forward movement of the cylinder  121  by controlling by the first protrusion  35 . For example, when there is no projectile in the hole  32 , the stopper  300  moves upward due to pressure of the first protrusion  35  to block the movement of the cylinder  121  toward the projectile fixing portion  33 , and when there is a remaining projectile  10  in the hole  32 , the stopper  300  moves downward to allow the movement of the cylinder  121  toward the projectile fixing portion  33  because the pressure of the first protrusion  35  is released. 
     Hereinafter, an operation of the toy gun with the configuration described above according to the first embodiment of the present invention will be described in detail. 
     To prepare for firing, the control unit  286  controls the power supply unit  210 , the driving motor  220 , the driving unit  201 , etc. to reciprocate the cylinder  121  (moving backward to moving forward) in the toy gun main body  110 . First, the rack gear portion  123  and the cam gear  230  engage to move the cylinder  121  backward while the cam gear  230  makes one rotation. Here, the piston  130  moves backward along with the cylinder  121 . 
     After this, when the cylinder assembly  120  and the piston  130  completely move back as illustrated in  FIG. 9 , the piston  130  is fixed by the locking member  250  in the state of being moved back, and the cylinder  121  moves forward by the return spring  125  as the rack gear portion  123  and the cam gear  230  are separated, as illustrated in  FIG. 10 . Here, when there is no projectile in the hole  32 , the plate  34   a  and the first protrusion  35  are spaced apart from each other as the plate  34   a  moves toward the hole  32 , and thereby the first protrusion  35  rotates upward. Accordingly, the first protrusion  35  blocks the cylinder  121  from moving toward the projectile fixing portion  33 . Conversely, when there is a remaining projectile  10  in the hole  32 , the first protrusion  35  allows the cylinder  121  to pass the connector  30  and move toward the projectile fixing portion  33  because the plate  34   a  lays down and fixes the first protrusion  35 . 
     The control unit  286  determines the position of the cylinder  121  and whether or not the backward and forward movement of the cylinder  121  is completed using the first sensor  281  while the cylinder  121  moves backward and forward. When the backward and forward movement of the cylinder  121  is not completed, the control unit  286  cuts power supplied to the driving unit  201  to prevent the cam gear  230  from rotating again. 
     In addition, even when a user pulls the trigger  270  before the cylinder  121  is not completely returned back to the initial position, the control unit  286  controls the locking member  250  to prevent the piston  130  from moving forward. 
     Conversely, when the cylinder  121  returns normally back to the initial position, the control unit  286  supplies power again to maintain a state ready to fire, and when a user pulls the trigger  270  in this state, the control unit  286  drives the driving motor  220  based on a switching signal of the second sensor  282 . Next, the cam gear  230  further rotates to make the cam portion  232  rotate the release lever  260 , and the piston  130  hooked by the locking member  250  interlocked with the interference bar  262  rotating as illustrated in  FIG. 11  is strongly launched by elastic force of the main spring  140 . In addition, the projectile  10  loaded into the cartridge chamber at front end of the cylinder assembly  120  is fired by the high pressure of air generated when the piston  130  rapidly returns back to the inside of the cylinder body  121   a.    
     As described above, the cam gear  230  is controlled to make one rotation, and an operation of firing one shot of the projectile  10  is performed by the one rotation of the cam gear  230 . 
     According to the toy gun of the embodiment of the present invention described above, since the cylinder assembly  120  is formed to perform the operation of moving backward and returning back along with the piston  130 , the projectile  10  is supplied to the space of the cartridge chamber  115  generated by the backward movement of the cylinder assembly  120 , and the projectile  10  is loaded as the cylinder assembly  120  returns back. However, since the connector  30  blocks the movement of the cylinder  121  when there is no projectile, unnecessary movement of the cylinder  121  may be prevented, and a user may be informed that there is no projectile. 
     In addition, a recoil force as is generated when a real gun is fired may be implemented through the operation of the cylinder assembly  120  that repeatedly moves backward and forward, that is, through the recoil generated when the cylinder assembly  120  returns back, and thereby providing a user with a sense of reality when firing. 
     Second Embodiment 
     As illustrated in  FIGS. 13 and 14 , a toy gun according to the second embodiment of the present invention has the same configuration and operation as the toy gun of the first embodiment except a connector  40  and a stopper  400 . 
     As illustrated in  FIG. 15 , the connector  40  of the second embodiment includes a connector body  41 , a hole  42 , a projectile fixing portion  43 , a projectile sensing portion  44 , a first protrusion  45 , a second protrusion  46 , and a cylindrical entrance  47 . The connector  40  may be fixed inside a toy gun main body  110  or may be inserted into the toy gun main body  110  along with a magazine  20  when the magazine  20  is inserted into the toy gun main body  110 . 
     The connector body  41 , the hole  42 , the projectile fixing portion  43 , the projectile sensing portion  44 , the second protrusion  46  and the cylindrical entrance  47  are the same as those in the first embodiment, but the first protrusion  45  is different from that in the first embodiment. 
     The first protrusion  45  is inserted into rear end of the connector body  41  to be vertically rotatable about a first rotating shaft  45   d . The first protrusion  45  is allowed to rotate by the projectile sensing portion  44  depending on whether or not a projectile remains in the hole  42 . In other words, the first protrusion  45  is fixed or allowed to rotate depending on a position of the projectile sensing portion  44 . In addition, when the first protrusion  45  is allowed to rotate by the projectile sensing portion  44 , the first protrusion  45  rotates by pressure of the stopper  400  which controls movement of a cylinder  121  in a toy gun  100 . 
     The first protrusion  45  includes a front end portion  45   a  in contact with rear end of the projectile sensing portion  44 , a rear end portion  45   b  pressed by the stopper  400 , and a rotating shaft  45   c  positioned between the front end portion  45   a  and the rear end portion  45   b  depending on whether or not a projectile remains in the hole  42 . A lower surface of the front end portion  45   a  is in contact with rear end of a plate  44   a , and a lower surface of the rear end portion  45   b  is pressed by the stopper  400 . In addition, the rear end portion  45   b  includes a slope in which a lower surface is formed to be longer than an upper surface, and the slope is formed so that the cylinder  121  easily passes above the connector  40 . 
     The first protrusion  45  is interlocked with the projectile sensing portion  44  to rotate, depending on whether or not a projectile remains in the hole  42 , and controls movement of the cylinder  121  by the rotation. For example, when there is a remaining projectile  10  in the hole  42  as illustrated in  FIGS. 16A and 16B , rear end of the plate  44   a  fixes the front end portion  45   a  not to rotate downward. Therefore, the rear end portion  45   b  blocks the stopper  400  from moving upward. Accordingly, the stopper  400  allows the cylinder  121  to pass the connector  40  and move toward the projectile fixing portion  43 . 
     Conversely, when there is no projectile in the hole  42  as illustrated in  FIGS. 17A and 17B , the plate  44   a  and the front end portion  45   a  are spaced apart from each other, as the plate  44   a  moves toward the hole  42 , and thereby the front end portion  45   a  is allowed to rotate downward about the rotating shaft  45   c . Therefore, the rear end portion  45   b  allows the stopper  400  to move upward. Accordingly, the stopper  400  blocks the cylinder  121  from moving toward the projectile fixing portion  43 . Here, although the rear end portion  45   b  itself may be formed to control the movement of the cylinder  121  by vertically rotating about the rotating shaft  45   c , the rear end portion  45   b  controls the movement of the cylinder  121  by allowing the stopper  400  to move upward in the present embodiment. 
     The stopper  400  is formed on a movement path of the cylinder  121  in a barrel portion  111  to block a forward movement of the cylinder  121  according to controlling by the first protrusion  45 . For example, when there is no projectile in the hole  42 , rotation of the first protrusion  45  is allowed, the stopper  400  moves upward due to elasticity of a spring  410  positioned thereunder, and thereby the stopper  400  blocks the cylinder  121  from moving toward the projectile fixing portion  43 . Conversely, when there is a remaining projectile  10  in the hole  42 , the first protrusion  45  is fixed, and thus the stopper  400  does not move upward but is fixed. Therefore, the stopper  400  allows the cylinder  121  to move toward the projectile fixing portion  43 . 
     Hereinafter, an operation of the toy gun with the configuration described above according to the second embodiment of the present invention will be described in detail. 
     To prepare for firing, the control unit  286  controls the power supply unit  210 , the driving motor  220 , the driving unit  201 , etc. to reciprocates the cylinder  121  (moving backward to moving forward) in the toy gun main body  110 . First, the rack gear portion  123  and the cam gear  230  engage to move the cylinder  121  backward while the cam gear  230  makes one rotation. Here, the piston  130  moves backward along with the cylinder  121 . 
     After this, when the cylinder assembly  120  and the piston  130  completely move back as illustrated in  FIG. 9 , the piston  130  is fixed by the locking member  250  in a state of being moved back, and the cylinder  121  moves forward by the return spring  125  as the rack gear portion  123  and the cam gear  230  are separated, as illustrated in  FIG. 10 . However, at this point, when there is no projectile in the hole  42 , the plate  44   a  and the first protrusion  45  are spaced apart from each other as the plate  44   a  moves toward the hole  42 , and thereby the front end portion  45   a  is allowed to rotate downward about the rotating shaft  45   c . Therefore, the rear end portion  45   b  allows the stopper  400  to move upward. Accordingly, the stopper  400  blocks the cylinder  121  from moving toward the projectile fixing portion  43 . Conversely, when there is a remaining projectile  10  in the hole  42 , the movement of the stopper  400  is blocked because the plate  44   a  fixes the first protrusion  45 . Therefore, the stopper  400  allows the cylinder  121  to move toward the projectile fixing portion  43 . 
     The control unit  286  determines the position of the cylinder  121  and whether or not the backward and forward movement of the cylinder  121  is completed using the first sensor  281  while the cylinder  121  moves backward and forward. When the backward and forward movement of the cylinder  121  is not completed, the control unit  286  cuts power supplied to the driving unit  201  to prevent the cam gear  230  from rotating again. 
     In addition, even when a user pulls the trigger  270  before the cylinder is not completely returned back to the initial position, the control unit  286  controls the locking member  250  to prevent the piston  130  from moving forward. 
     Conversely, when the cylinder  121  returns normally back to the initial position, the control unit  286  supplies power again to maintain a state ready to fire, and when a user pulls the trigger  270  in this state, the control unit  286  drives the driving motor  220  based on a switching signal of the second sensor  282 . Next, the cam gear  230  further rotates to make the cam portion  232  rotate a release lever  260 , and the piston  130  hooked by the locking member  250  interlocked with the interference bar  262  rotating as illustrated in  FIG. 11  is strongly launched by elastic force of the main spring  140 . In addition, the projectile  10  loaded into the cartridge chamber at front end of the cylinder assembly  120  is fired by high pressure of air generated when the piston  130  rapidly returns back to the inside of the cylinder body  121   a.    
     The connector for a toy gun according to the present invention can sense and informs a user whether or not a projectile provided by the magazine remains. 
     In addition, the connector for a toy gun according to the present invention can control cocking of the toy gun depending on whether or not a projectile provided by the magazine remains. 
     Although exemplary embodiments to describe the principle of the present invention are illustrated and described as above, the present invention is not limited to the configurations and operations as are illustrated and described herein. Rather, it should be understood by those skilled in the art that various changes and modifications may be made therein without departing from the scope and the technical spirit of the invention.