Patent Publication Number: US-9903684-B2

Title: High pressure air system for airsoft gun

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This Application claims the benefit of U.S. Provisional Patent Application Ser. No. 62/020,458, filed Jul. 3, 2014, and of U.S. Provisional Patent Application Ser. No. 62/048,590, filed Sep. 10, 2014. The content of both foregoing applications is incorporated herein by reference. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable 
     BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     The present invention pertains generally to airsoft guns and, more particularly, to a high pressure fluid mechanisms to be used in airsoft guns. 
     2. Description of the Related Art 
     Airsoft guns employ compressed air fire round plastic pellets or similar projectiles, usually ranging from 0.12 g to 0.48 g. Airsoft players often fire airsoft guns at other players during airsoft games and competitions. 
     Various “firing” mechanisms are known in the art for airsoft guns. For instance, U.S. Pat. No. 7,527,049, issued to Sheng, discloses a pneumatic pusher having a main body, a flow-guiding body, a moving body, and a delivery tube. The flow-guiding body includes a front tube with a smaller diameter and a rear tube with a larger diameter. The delivery tube is mounted on the front tube in such a way that the outer wall of the delivery tube and the inner wall of the main body define a return pressure chamber. A first gas-distributing channel extending from a first air outlet at one side of the main body leads directly to the inner side of the delivery tube. The side of the first air inlet of the main body communicates with a second gas-distributing channel. The second gas-distributing channel includes an exit located at one side of the return pressure chamber of the delivery tube. The air pressure provided through the second gas-distributing channel serves as cushioning force in pushing the delivery tube outwardly. 
     U.S. Pat. No. 8,453,633, issued to Tsai, discloses a spring-piston airsoft gun that includes a cylinder-and-piston assembly disposed in a barrel to force air through a muzzle end to make a shooting action, and a coil spring disposed to exert a biasing action to drive a piston head of the cylinder-and-piston assembly when changed from a compressed state to a released state. Front and rear anchor shanks are disposed for respectively mounting front and rear coil segments of the coil spring. A major shell and a minor ring are sleeved on the rear anchor shank to permit the coil spring to be sleeved thereon. The minor ring is in frictional contact with and angularly moveable relative to the major shell such that, when the coil spring is released to expand to the released state, the rear coil segment is tensed to drag the minor ring to angularly move therewith so as to minimize the frictional force therebetween. 
     U.S. Pat. No. 8,671,928, issued to Hague et al. and assigned to Polarstar Engineering &amp; Machine, discloses a pneumatic assembly for a projectile launching system includes a body defining a continuous bore. A nozzle is positioned within the bore adjacent a forward end and is moveable between a rearward position wherein the nozzle facilitates passage of a projectile through a projectile port and a forward position wherein the nozzle prevents passage of a projectile through the projectile port. The nozzle is biased to the forward position and configured for fluid actuation to the rearward position by activation of a first fluid control valve. A valve seat defines an accumulation chamber rearward of the nozzle. A firing valve member is moveable between a forward position wherein the firing valve member fluidly seals a passage through the valve seat and a rearward position wherein the passage is fluidly opened such that fluid in the accumulation chamber is free to flow through the passage and out of the nozzle. Example embodiments of this pneumatic assembly generally include a nozzle spring contained between the rear surface of the nozzle and the front surface of a center cylinder. 
     U.S. Patent Application Publication Number 2012/0216786, by Hadley and Calvin, teaches a soft impact projectile launcher including a launching mechanism that creates a burst of air or air pressure in order to launch a projectile. The launching mechanism includes an outer cylinder and a spring-loaded piston configured to generate the burst of air. The projectile launcher may also include a projectile reservoir and a loading member that positions projectiles for launching. The projectile launcher can launch projectiles that are made from a superabsorbent polymer and consist of mostly water. 
     U.S. Patent Application Publication Number 2013/0247893, by Yang, teaches an airsoft gun structure designed to shunt high-pressure air flow during shooting. Therefore, the shunted high-pressure air flow simulates recoils as real bolt-action, single-shot rifles. Also, the ammunition supply includes different cartridges to select one of the supply-type by the users and whether shell case ejection or not. When operates the airsoft gun, the realistic action is achieved to enhance the fun of shooting. Furthermore, the dual hop up system makes the flight path of bullets more stable without shift. Moreover, the safety gasification system could make the supplied amount of the output compressed high pressure air be almost constant to enhance security during operation. The devices disclosed in Yang include a hammer block spring or magazine spring attached to an inner surface of the back block in an inner barrel. 
     BRIEF SUMMARY OF THE INVENTION 
     The present general inventive concept, in some of its many embodiments, encompasses a springless high pressure air cylinder to use in an airsoft gun or similar devices and systems. In some embodiments, the present general inventive concept encompasses a cylinder in which an imbalanced poppet valve directs and controls the axial motion of a piston. Some embodiments include a two-way solenoid valve. The solenoid valve controls the flow of air to drive a piston forward; air then pushes the piston back into place. 
     In some embodiments of the present general inventive concept, a springless high pressure air cylinder for use in an airsoft gun includes a cylinder frame body, a piston having a nozzle member and a piston base member, the piston base member moving within the cylinder frame body along an axis, the piston base member including a first piston head surface and a second piston head surface, the piston being capable of moving between a forward position and a back position, a solenoid valve to direct air to the piston base member, whereby air pressure on the first piston head surface moves the piston from the back position to the forward position, and an auxiliary line to direct air against the second piston head surface, whereby air pressure on the second piston head surface moves the piston from the forward position to the back position. 
     In some embodiments, the auxiliary line is a part of the cylinder frame body. In some embodiments, the auxiliary line is separate from the cylinder frame body. 
     In some embodiments, the solenoid valve is a two-way solenoid valve. 
     Some embodiments further encompass a baffle member interposed between said piston base member and said cylinder frame body. 
     In some embodiments of the present general inventive concept, a high pressure air cylinder-nozzle assembly includes a cylinder frame body, a piston having a nozzle member and a piston base member, the piston base member moving within the cylinder frame body, the piston being capable of moving between a forward position and a back position, the piston base member including a primary piston head surface and a secondary piston head surface, a solenoid valve to direct air to the piston base member at a location proximate the primary piston head surface, air pressure on the primary piston head surface moving the piston from the back position to the forward position, and a secondary air line to direct air against the secondary piston head surface, air pressure on the secondary piston head surface moving the piston from the forward position to the back position. 
     Certain embodiments are further characterized in that the high pressure air cylinder-nozzle assembly is used in an airsoft gun. 
     Certain embodiments are further characterized by a spring positioned within the cylinder frame body to assist in moving the piston from the forward position to the back position. 
     Certain embodiments are further characterized by a spring positioned within the cylinder frame body to assist in moving the piston from the back position to the forward position. 
     Certain embodiments are further characterized in that the secondary air line is a part of the cylinder frame body. 
     Certain embodiments are further characterized in that the solenoid valve is a two-way solenoid valve. 
     Some embodiments further encompass a baffle member interposed between said piston base member and said cylinder frame body. 
     Certain embodiments are further characterized in that said baffle member includes air slits air slits permitting passage of air from said secondary air line to said secondary piston head surface when said piston from is in the forward position. 
     Certain embodiments are further characterized in that the primary piston head surface and the secondary piston head surface are opposing surfaces of one piston member. 
     In some embodiments of the present general inventive concept, a high pressure cylinder for use in a gun includes a cylinder frame body, a piston having a nozzle member and a piston base member, the piston base member moving within the cylinder frame body along an axis, the piston base member including a first piston head surface and a second piston head surface, the piston being capable of moving between a forward position and a back position, a solenoid valve to direct a fluid to the piston base member, whereby fluid pressure on the first piston head surface moves the piston from the back position to the forward position, and an auxiliary fluid line to direct fluid against the second piston head surface, whereby fluid pressure on the second piston head surface moves the piston from the forward position to the back position. 
     In some embodiments, the auxiliary line is a part of the cylinder frame body. 
     In some embodiments, the solenoid valve is a two-way solenoid valve. 
     Some embodiments further encompass a baffle member interposed between said piston base member and said cylinder frame body. 
     In some embodiments, said baffle member includes air slits permitting passage of air from said secondary air line to said secondary piston head surface when said piston from is in the forward position. 
     In some embodiments, said primary piston head surface and said secondary piston head surface are opposing surfaces of one piston member. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above-mentioned and additional features of the invention will become more clearly understood from the following detailed description of the invention read together with the drawings in which: 
         FIG. 1  is a section view of a cylinder-nozzle assembly according to one example embodiment of the present general inventive concept, showing the piston and nozzle in the “back” position; 
         FIG. 2  is a second section view of the example embodiment cylinder-nozzle assembly shown in  FIG. 1 , showing piston and nozzle in the “forward” position; 
         FIG. 3  is a perspective view of a cylinder-nozzle assembly according to one example embodiment of the present general inventive concept; 
         FIG. 4  is an exploded view of the example embodiment shown in  FIG. 3 ; 
         FIG. 5  is a top-down view of the example embodiment shown in  FIGS. 3 and 4 , showing the section-line along which is taken the views of  FIGS. 6 and 7 ; 
         FIG. 6  is a section view of the example embodiment cylinder-nozzle assembly shown in  FIGS. 3-5 , showing piston and nozzle in the “back” position; 
         FIG. 7  is a second section view of the example embodiment cylinder-nozzle assembly shown in  FIGS. 3-6 , showing piston and nozzle in the “forward” position; and 
         FIG. 8  is a perspective view of another cylinder-nozzle assembly according to another example embodiment of the present general inventive concept, showing a cylinder-nozzle assembly with an off-set nozzle. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Disclosed herein are various example embodiments of a springless high pressure air cylinder to use in an airsoft gun or similar devices and systems. In some embodiments, the present general inventive concept encompasses a cylinder in which an imbalanced poppet valve directs and controls the axial motion of a piston. Some embodiments include a two-way solenoid valve. The solenoid valve controls the flow of air to drive a piston forward; air then pushes the piston back into place. 
     Turning to the figures,  FIG. 1  shows a cross-section view of one example embodiment of a cylinder-nozzle assembly according to the present general inventive concept. In  FIG. 1 , the cylinder-nozzle assembly  100  includes a cylinder frame body  110 , a piston  210 , and a solenoid  310 . A substantial portion of the piston  210  fits within the cylinder frame body  110  and moves within the cylinder frame body  110 . The piston  210  includes a nozzle  215  (which defines the central air channel  230 ) and a piston head portion  220 . 
       FIG. 1  shows the cylinder-nozzle assembly  100  with the piston  210  in a “back” or rest position. In the back position, the piston head portion  220  and part of the nozzle  215  fit within an interior volume  150  defined by the surrounding cylinder frame body  110 , and the piston head portion  220  of the piston  210  fits closely (but generally not in an air-tight fit) against and partially wraps around a central head member  325 . To move the piston  210 , high pressure air enters the assembly through an air input channel  115 , which feeds to a HPA compartment  120 . From the HPA compartment  120 , air passes through a solenoid input channel  125  into the solenoid  310 . Within the solenoid  310  is a valve, which is capable of switching between a closed state and an open state. When a trigger mechanism of the airsoft gun activates the solenoid  310 , the valve within the solenoid  310  switches into its open state, allowing the passage of air from the input channel through the solenoid  310  and into an antepiston compartment  320  defined by the cylinder frame body  110  and proximate to the piston head portion  220  of the piston  210 . 
     As air flows into the antepiston compartment  320 , the air pushes on a primary piston head surface  222 . Air pressure on the primary piston head surface  222  pushes the piston  210  forward within the cylinder frame body  110 , until the piston  210  is in a “forward” position, illustrated in  FIG. 2 . Once the piston  210  is in the forward position, air from the solenoid  310  passed into the antepiston compartment  320  is free to travel through the open space  245  between the piston head portion  220  and the central head member  325 ; from there the air passes through the central air channel  230  defined by the nozzle  215 . 
     With the piston  215  in the forward position, the valve within the solenoid  310  closes, and high pressure air being fed into the HPA compartment  120 , instead of flowing through the solenoid  310 , flows through an auxiliary tube  130  and auxiliary line  135  into a forward air feed tube, which feeds the air into a forward air compartment  145  within the cylinder frame body  110 . The air in the forward air compartment  145  exerts pressure on a secondary piston head surface  224 , and that pressure drives the piston  210  to return to the back position shown in  FIG. 1 . 
     In some embodiments of the present general inventive concept, the two piston surfaces are opposite sides of the same piston, with the center diameter of the two sides differing—thereby leading to a difference in the surface area of the two piston surfaces. 
     Some further example embodiments of the present general inventive concept include assemblies in which a spring positioned within the cylinder frame body assists in returning the piston to the back position. This spring, then, supplements the motive force of the air supplied by the auxiliary line. Some further example embodiments of the present general inventive concept include assemblies in which a spring positioned within the cylinder frame body assists in returning the piston to the forward position. This spring, then, supplements the motive force of the air supplied by the auxiliary line 
     In some embodiments, the cylinder-nozzle assembly is designed to fit into an existing gear box. In some embodiments, the cylinder-nozzle assembly is designed to operate as a stand-alone unit to fit into an airsoft gun or other similar device or system. 
       FIGS. 3-7  illustrate one example embodiment of a cylinder-nozzle assembly according to the present general inventive concept. As shown in the perspective view in  FIG. 3 , and in the exploded view of the same embodiment in  FIG. 4 , the assembly  400  includes a frame body  410 , a piston  510  with nozzle  515  and piston base  520 , and a solenoid  610 . In the illustrated example embodiment, as shown in the cross-sectional view in  FIG. 6 , a substantial portion of the piston  510  fits within the cylinder frame body  410  and moves within the cylinder frame body  410 . The piston  510  includes a nozzle  515  (which defines a central air channel  530 ) and a piston base  520 . As shown in the exploded view of  FIG. 4  and in the cross-sectional views in  FIGS. 6 and 7 , a baffle member  540  fits over the piston base  520 ; the piston base  520  moves within the volume enclosed by the baffle member  540 , and the baffle member  540  includes an aperture permitting through-passage by the nozzle  515 . In some embodiments, the baffle member  540  includes one or more air slits  542  proximate the aperture and the nozzle  515 . 
     The cross-sectional view of  FIG. 6  shows the cylinder-nozzle assembly  400  with the piston  510  in a “back” or rest position. In the back position, the piston base  520  sits within the baffle member  540  and the cylinder frame body  410  positioned towards the solenoid  610 . The piston base  520  fits closely (but generally not in an air-tight fit) against and partially wraps around a central head member  625  of the solenoid  610 . 
     To move the piston  510 , high pressure air enters the assembly through an air input channel to a HPA compartment  415 . From the HPA compartment  415 , air passes through a solenoid input channel  425  into the solenoid  610 . Within the solenoid  610  is a valve, which is capable of switching between a closed state and an open state. When a trigger mechanism of the airsoft gun activates the solenoid  610 , the valve within the solenoid  610  switches into its open state, allowing the passage of air from the input channel through the solenoid  610  and into an antepiston compartment defined by the cylinder frame body  110  and proximate to both the central head member  625  and to the piston base  520 . As air flows into the antepiston compartment, the air pushes on a primary piston head surface. Air pressure on the primary piston head surface pushes the piston base  520  forward within the cylinder frame body  410  and baffle member  540 , until the piston  510  is in a “forward” position, illustrated in the cross-sectional view in  FIG. 7 . Once the piston  510  is in the forward position, air from the solenoid  610  passed into the antepiston compartment is free to travel through the open space between the piston base  520  and the central head member  325 ; from there the air passes through the central air channel  530  defined by the nozzle  515 . 
     With the piston  510  in the forward position, the valve within the solenoid  610  closes, and high pressure air being fed into the HPA compartment  415 , instead of flowing through the solenoid  610 , flows through a secondary air line  435 , which feeds the air into a forward air compartment within the cylinder frame body  410 . The air in the forward air compartment exerts pressure on a secondary piston head surface, and that pressure drives the piston  510  to return to the back position shown in  FIG. 6 . In some example embodiments, the air slits  542  in the baffle member  540  permit the passage of air from the secondary air line to the secondary piston head surface. In some embodiments, the primary piston head surface and the secondary piston head surface are opposing surfaces of one piston member. In some embodiments, the two piston surfaces are opposite sides of the same piston, with the center diameter of the two sides differing—thereby leading to a difference in the surface area of the two piston surfaces. 
     In the example embodiments illustrated thus far, the nozzle is substantially centered with respect to the cylinder frame body. However, other configurations are contemplated by the present general inventive concept. For example,  FIG. 8  shows a perspective view of a cylinder-nozzle assembly  405  with an off-set nozzle  516 . Other variations and configurations will be apparent to those of skill in the art and are also within the scope of the present general inventive concept. 
     While the present invention has been illustrated by description of several embodiments and while the illustrative embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and methods, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of applicant&#39;s general inventive concept.