Patent Publication Number: US-2006011183-A1

Title: Gas distribution device with controlled pressure relief

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The invention relates generally to devices for distributing compressed gas from high pressure gas reservoirs, and more particularly to an arrangement for relieving pressure in such devices prior to disconnection of the high pressure gas reservoir.  
      2. Description of the Related Art  
      Gas powered projectile launching devices used in the game of paintball are well known. These gas powered devices (otherwise known as paintball markers) employ portable compressed gas cylinders to supply the necessary pneumatic power. The compressed gas is most commonly compressed air or compressed carbon dioxide. Increasing the amount of compressed gas that can be connected to a paintball player&#39;s marker has been the object of much development in the field of paintball markers.  
      One recent trend is toward the use of very high pressure compressed gas cylinders. These cylinders increase the quantity of available compressed gas by storing the gas at pressures in the range of 4,500 to 5,500 p.s.i. These very high-pressure gas storage cylinders typically include a first regulator built into the cylinder, which releases gas from the cylinder at a pressure of approximately 800 p.s.i. Gas at this pressure is fed through a distribution device and associated plumbing to a second regulator on the marker where the pressure is further reduced to a range of between 50 and 100 p.s.i. for use by the marker. The very high pressure storage cylinder typically includes a threaded coupling which is threadably received by the device for distributing pressurized gas from the cylinder to the regulator attached to the paintball marker. These distribution devices typically include a control knob attached to a threaded shaft that allows axial manipulation of a pin for depressing a valve pin on the compressed gas cylinder. When the compressed gas cylinder is threadably coupled to the gas distribution device, the control knob is rotated such that the pin is axially moved toward the gas cylinder. The pin depresses the cylinder valve pin and releases compressed gas from the cylinder into the distribution device which communicates with passages and tubes leading to the regulator of the paintball marker. When the cylinder valve pin is depressed, the internal passages of the distribution device and the tubes leading to the paintball marker are pressurized at approximately 800 p.s.i.  
      When the paintball marker is not being used, it is desirable to remove the compressed gas cylinder from the paintball marker so that it may be stored and/or refilled. Commonly, the compressed gas cylinder is not completely exhausted and therefore the gas distribution device and associated plumbing are filled with compressed gas at approximately 800 p.s.i. This is true even after the control knob has been rotated to withdraw the pin away from the compressed gas cylinder and release the valve pin of the cylinder shutting off flow from the cylinder to the gas distribution device and associated plumbing. The pressure in the distribution device and plumbing complicates removal of the compressed gas cylinder by exerting pressure on the threads of the cylinder/device coupling. This pressure increases the difficulty of the unthreading the cylinder from the coupling. Further, the compressed gas in the device and associated plumbing presents the hazard of explosive release of the cylinder from the coupling. Such explosive release can harm the user and/or damage the costly and fragile gas reservoir.  
      Thus, it is necessary to relieve pressure in the gas distribution device and associated plumbing prior to removal of the compressed gas cylinder. This has been accomplished by cycling the paintball marker several times after shutting off gas flow from the cylinder. As a safety feature, the coupling of the distribution device may be provided with a vent hole positioned to vent pressure from the distribution device before the threaded connection between the reservoir in the coupling is completely released. The vent prevents the explosive release of gas during removal of the reservoir from the coupling.  
      There is a need in the art for a gas distribution device that enhances the convenience and safety of removing a high-pressure gas reservoir from a paintball marker.  
     SUMMARY OF THE INVENTION  
      Briefly stated, the invention is a gas distribution device including an exhaust hole that is uncovered by backing off the control knob to bleed pressurized gas from the distribution device and the associated plumbing. The improved gas distribution device provides a simple, safe and convenient means of controlled pressure relief without cycling the marker or removing the compressed gas cylinder. According to aspects of the present invention, the distribution device includes a coupler configured to receive and mate with a compressed gas cylinder. The device defines a high-pressure chamber having at least one pressure port for distributing pressurized gas to the paintball marker or other pneumatic equipment. The device includes a control knob attached to a threaded shaft which is threadably engaged in an end of the device opposite the coupling. The shaft extends to a pin configured and positioned for depressing and releasing the valve pin of the compressed gas cylinder. Rotation of the control knob in a first direction moves the pin toward the cylinder to depress the valve pin and pressurize the system. Rotation of the control knob in a second direction withdraws the pin away from the cylinder, releasing the valve pin and shutting off gas flow.  
      A feature of the present invention relates to an unthreaded portion of the bore in which the actuator travels. The shaft of the actuator is provided with a circumferential groove and a seal compressed between the shaft and the inside surface of the unthreaded portion of the bore. The exhaust hole communicates with the actuator travel portion of the bore at an axial position selected to facilitate venting of gas from the device after the valve pin of the compressed gas cylinder has been released. The control knob is rotated in the second direction to release the valve pin and shut off flow of gas from the reservoir. To vent the system the user simply continues rotating the control knob in the second direction until the seal on the shaft axially uncovers the exhaust hole. Pressurized gas from the distribution device and associated plumbing is released in a controlled manner through the exhaust hole. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  illustrates a pneumatically operated device for launching a projectile operatively connected to a gas distribution device according to aspects of the present invention in an “on” or pressurized condition;  
       FIG. 2  is the pneumatically operated device for launching a projectile and gas distribution device of  FIG. 1  illustrated in the “vented” position; and  
       FIG. 3  is the gas distribution device of  FIGS. 1 and 2  illustrated in the “off” but not vented position. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
      A gas distribution device  10  according the aspects of the present invention comprises a body  12  having first and second ends  14 ,  16  and defining a bore. The bore includes a gas source receiving portion or coupling  18  for removably engaging a compressed gas cylinder  20 . A high pressure portion  22  of the bore communicates with the coupling  18  and includes at least one high pressure port  24  for distributing pressurized gas to the paintball marker  30 . An actuator travel portion  26  of the bore communicates with the high-pressure chamber  22  and extends between the chamber and the second end  16  of the body  12 . In the illustrated embodiment, the actuator travel portion  26  includes a threaded portion  27  and an unthreaded portion  28 . An actuator  32  extends from a control knob  34  to a pin  36 . The control knob  34  and pin  36  are connected to a shaft  38  that is at least partially threaded for engagement with the threaded portion  27  of the actuator travel bore  26 . In the illustrated embodiment, the shaft  38  is provided with a circumferential groove  40  in which is lodged a seal  42 . The seal  42  is compressed between the shaft  38  and the unthreaded portion  28  of the actuator travel bore  26  to prevent gaseous communication between the high-pressure chamber  22  and the exhaust hole  44 . The exhaust hole  44  is axially positioned such that when the actuator  32  is in the position shown in  FIG. 1 , the seal  42  is between the pressurized portions ( 22 ,  24 ,  28 ) of the gas distribution device  10  and the exhaust hole  44 . Counter rotation of the control knob  34  withdraws the pin  36  of the actuator away from the gas cylinder to release the valve pin  46  of the gas cylinder  20  and shut off flow of pressurized gas as shown in  FIG. 3 . In  FIG. 3 , the flow of pressurized gas from the reservoir is shut off, but the pressurized portions ( 22 ,  24 ,  28 ) of the gas distribution device  10  and associated plumbing have not yet been vented.  FIG. 2  illustrates the actuator  32  in the vent position. The vent position is achieved by counter rotation of the control knob  32  from the “off” position shown in  FIG. 3 . The vent position permits a controlled release of pressure from the gas distribution device  10  and associated plumbing without cycling the paintball marker  30  or removing the compressed gas cylinder  20 .  
       FIGS. 1 and 2  illustrate a basic use environment for a gas distribution device  10  according to aspects of the present invention. A paintball marker  20  is schematically shown. The paintball marker  20  employs compressed gas and electro-pneumatic or mechanical valves (not shown) to propel a paintball  48  out of a barrel  50 . The type of marker and its function do not form any part of the present invention. The paintball marker  20  is typically equipped with an on board regulator  52  which reduces the pressure of gas fed to the marker to a level compatible with the internal mechanism of the marker. Plumbing, usually in the form of tubing  54  extends between the gas distribution device  10  and the regulator  52  of the paintball marker. The tubing  54  is connected to a high-pressure port  24  of the gas distribution device. A compressed gas cylinder  20  is partially shown in  FIGS. 1 and 2 . The compressed gas cylinder  20  typically includes an internal regulator  56  for limiting the pressure of gas released from the cylinder. The cylinder  20  also includes a valve  58  with a valve pin  46  which when releases gas from the cylinder when depressed. As seen in  FIGS. 1 and 2  the coupler  18  of the gas distribution device is configured to threadably mate with the gas cylinder  20 . The coupling end  60  of the cylinder includes a circumferential groove and seal  62 .  
      While a preferred embodiment of the foregoing invention has been set forth for purposes of illustration, the foregoing description should not be deemed a limitation of the invention herein. Accordingly, various modifications, adaptations, and alternatives may occur to one skilled in the art without departing from the spirit and the scope of the present invention.