Patent Publication Number: US-7712464-B2

Title: Valve for paint ball guns

Description:
BACKGROUND OF THE INVENTION 
   (1) Field of the Invention 
   The present invention relates to a paint ball gun, and more particularly, to a valve for a paint ball gun and the valve is operated with less force. 
   (2) Description of the Prior Art 
   A conventional paint ball gun generally includes a valve which includes a spring biasing a piston rod so as to seal passages to prevent the pressurized air from entering the barrel to shoot the paint balls when the trigger is not yet pulled. The piston rod includes a flange which is applied a force by the pressurized air so that when the trigger is pulled, the force that is used to move the piston rod has to overcome the combination force of the spring and the force from the pressurized air. In order to generate the sufficient force to move the piston rod, a significant amount of pressurized air is introduced to a space located at rear end of the driving member that pushes the piston rod. In other words, the pressurized air source has to dispense a certain amount of the pressurized therein to move the drive the driving member and this reduces the times of shooting. 
   The present invention intends to provide a valve for a paint ball gun and the valve includes a piston rod which has piston rings of different areas so that the piston rod can be moved with less force. 
   SUMMARY OF THE INVENTION 
   The present invention relates to a valve for paint ball guns and the valve comprises a case having a first chamber, a second chamber and a third chamber defined therein. An inlet communicating with the first chamber and an outlet communicating with the second chamber are respectively through a wall of the case. A first piston rod is a hollow and tubular member and received in the case. A first piston ring is mounted to the first piston rod and movable between a first position and a second position thereof. The first piston ring seals the communication between the first and second chambers when the first piston ring is in the first position. The first and second chambers are in communication with each other when the first piston ring is in the second position. A second position ring is connected to the first piston rod and separates the second and third chambers. A fourth chamber is defined in the first piston rod and communicates with the third chamber. 
   A second piston rod has a first end received in the first piston rod. An introduction hole is defined through a wall of the first piston rod and communicates with the fourth chamber. A third piston ring is connected to the second piston rod and located in the fourth chamber. The third piston ring is movable between a first position and a second position. The introduction hole is sealed by the third piston ring when the third piston ring is at the first position thereof. The introduction hole is opened by the third piston ring when the third piston ring is at the second position thereof. A driving member pushes a second end of the second piston rod to move the second piston rod from the first position to the second position thereof so that pressurized air in the first chamber enters into the fourth chamber and the third chamber via the introduction hole to move the first piston rod from the first position to the second position thereof. 
   The present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a preferred embodiment in accordance with the present invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a side cross sectional view of the valve of the present invention; 
       FIG. 2  is an exploded view to show the valve of the present invention; 
       FIG. 3  is a side cross sectional view of the valve of the present invention, wherein pressurized air is filled in the first chamber; 
       FIG. 4  is a side cross sectional view of the valve of the present invention, wherein pressurized air is filled in the first chamber, wherein the second piston rod is pushed and pressurized air releases from the outlet, and 
       FIG. 5  is a partial cross sectional view to show that the valve of the present invention is installed to a paint ball gun. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring to  FIGS. 1 ,  2  and  5 , the paint ball gun  1  comprises a barrel  3  and the valve  2  of the present invention is located below the barrel  1 . A handle is connected to the barrel  1  and a trigger (not shown) is connected to the handle so as to activate the valve  2 . The valve  2  introduces pressurized air into the barrel  3  to shoot the paint balls (not shown) in the barrel  3 . 
   The valve  2  for the paint ball gun  1  of the present invention comprises a case which includes two open ends and a first chamber  23 , a second chamber  24  and a third chamber  25  are defined in the case. A flange  22  extends inward from the inner periphery of the case. An inlet  20  and an outlet  21  are respectively through a wall of the case  2 . The inlet  20  communicates with the first chamber  23  and the outlet  21  communicates with the second chamber  24 . A sealing member (not numbered) is connected to a side of the flange  22  and located between the inlet  20  and the outlet  21 . 
   A hollow and tubular first piston rod  10  received in the case  2  and a first piston ring  101  is mounted to the first piston rod  10  and movable between a first position and a second position thereof. A second position ring  11  is connected to the first piston rod  10  and engaged with the inner periphery of the case so as to separate the second and third chambers  24 ,  25 . An area of the second piston ring  11  is larger than that of an end surface of the first piston rod  10 . The first piston ring  101  seals the communication between the first and second chambers  23 ,  24  when the first piston ring  101  is in the first position as shown in  FIG. 3 . The first and second chambers  23 ,  24  are in communication with each other when the first piston ring  101  is in the second position as shown in  FIG. 4 . 
   A fourth chamber  12  is defined in the first piston rod  10  and communicates with the third chamber  25  via an annular passage  60  defined between the inner periphery of the first piston rod  10  and a second piston rod  40  movably received in the first piston rod  10 . 
   The second piston rod  40  has a first end received in the first piston rod  10 . An introduction hole  14  is defined through a wall of the first piston rod  10  and communicates with the fourth chamber  12 . A third piston ring  42  is connected to the second piston rod  40  and located in the fourth chamber  12 . The third piston ring  42  is movable between a first position and a second position. The introduction hole  14  is sealed by the third piston ring  42  when the third piston ring  42  is at the first position thereof as shown in  FIG. 3 . The introduction hole  14  is opened by the third piston ring  42  when the third piston ring  42  is at the second position thereof as shown in  FIG. 4 . 
   An end cap  30  is engaged with and seals one of the two open ends. A spring  31  has one end contacting the end cap  30  and the other end of the spring  31  is mounted to the first piston rod  10  and biases the first piston ring  101 . A ring-shaped member  50  is engaged with the other open end of the case  2  and the second end of the second piston rod  40  extends through the ring-shaped member  50 . An annular passage  41  is defined between the second piston rod  40  and an inner periphery of the ring-shaped member  50 . A second spring  13  is located in the fourth chamber  12  and biased between the third piston ring  42  and a fourth piston ring  102  engaged with an end of the first piston rod  10 . 
   A driving member  4  is located corresponding to the second end of the second piston rod  40 . As shown in  FIG. 4 , when the user pulls the trigger (not shown), the driving member  4  pushes the second end of the second piston rod  40  to move the second piston rod  40  from the first position to the second position thereof so that pressurized air in the first chamber  23  enters into the fourth chamber  12  and the third chamber  25  via the introduction hole  14  to move the first piston rod  10  from the first position to the second position thereof. 
   An area of the first piston rod  10  is larger than that of an end surface of the second piston rod  40 , and an area of the second piston rod  40  in the fourth chamber  12  is 10% to 50% of an end surface of the first piston rod  10  in the first chamber  23 . Therefore, when the second piston rod  40  is pushed by the driving member  4 , the force from the driving member  4  overcomes the force of the second spring  13 , the first piston ring  101  is moved to open the first and second chambers  23 ,  24 , the pressurized air enters the second chamber  24  and goes through the outlet  21  and enters into the barrel  3  to shoot the paint ball in the barrel  3 . Some of the pressurized air enters the introduction hole  14  and goes through the annular passage  60  and enters into the third chamber  25 . The pressurized air applies to the second piston ring  11  and generates a force to overcome the force of the first spring  31  and the force applied to the end surface of the first piston rod  10 , so that the first piston rod  10  can quickly move from the first position to the second position. 
   After shooting, the remained pressurized air in the third chamber  25  releases from the annular passage  41 , the first and second springs  31 ,  13  push the first and second piston rods  10 ,  40  back to their original positions. 
   While we have shown and described the embodiment in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.