Abstract:
A valve, possibly for use in a paintball marker, has a longer threaded portion that insures a canister that engages the valve must undergo many twists to become unscrewed from the valve. Alternatively, the valve has an elongated threaded portion with gas bleed channels that extend along a substantial portion of the threading. Still alternatively, the valve may use visual markings along the length of the threaded portion to indicate to a user that the canister is being unscrewed.

Description:
[0001]    This application is a Continuation of U.S. patent application Ser. No. 11/600,285, filed Nov. 15, 2006, now U.S. Pat. No. 7,383,833, issued Jun. 10, 2008, which is a Continuation of U.S. patent application Ser. No. 11/485,067, filed Jul. 12, 2006, now U.S. Pat. No. 7,231,912, issued Jun. 19, 2007, which is a Continuation of U.S. patent application Ser. No. 11/001,716, filed Dec. 2, 2004, now U.S. Pat. No. 7,163,008, issued Jan. 16, 2007, which claims the benefit of U.S. Provisional Patent Application No. 60/604,762, filed Aug. 26, 2004, the entire contents of all of which are incorporated by reference as if fully set forth herein. 
     
    
     BACKGROUND 
       [0002]    In the sport of paintball, players use a paintball gun or “marker,” to fire ammunition (paintballs) that bursts upon impact. To generate the force necessary to burst the paintballs on impact, paintball markers drive the paintballs using compressed gas, usually Carbon Dioxide (CO2) or a Nitrogen/High Pressure Air (N2/HPA) mixture These gases are stored in compressed gas tanks, also referred to collectively as gas tanks, air tanks, air canisters, or canisters. 
         [0003]    The tank comprises, generally, a canister, and a valve closing off an open end of the canister. One end of the valve is designed to securely screw into the canister, usually by threaded engagement. Another end of the valve is threaded for engagement with a portion of, for example, a paintball marker, or a paintball marker accessory that is designed to receive the tank. 
         [0004]      FIG. 1  shows standard valve  10  used in threaded engagement with a canister (not shown), a burst disk assembly  15  that engages the valve through the hole  15   a  (shown in phantom), and a threaded portion  16  for engaging an air tank. Internally, the valve  10  comprises a depressor pin  20 , a depressor pin spring  22 , and a retainer plug  24 . The threaded portion  16 , may be provided with a vent hole  17  that releases pressure built up inside the valve to atmosphere. 
         [0005]    There are drawbacks of these prior art canister and valve combinations, especially as the canister begins unscrewing from the valve. During intentional or unintentional unscrewing, pressure from the compressed gas inside the canister presses against the valve and can unexpectedly separate the canister and valve as the engaged threads between the canister and valve decrease. The only known safety mechanism for the valve and canister interface is directed at pressure relief from inside the valve and is shown in prior art  FIG. 1 . 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention seeks to overcome the pressure release problem as the canister is unscrewed from the valve. To solve this problem, the invention shows at least six embodiments. The first shows a valve with a longer threaded portion that insures the canister must undergo many twists to become unscrewed from the valve. The second is a valve with an elongated threaded portion having gas bleed channels that extend along a substantial portion of the threading. The third is a standard threaded portion valve with the gas bleed channels. The fourth is a series of channels that extend along the threaded portion for short spans (usable with the standard or elongated threaded portion). The fifth uses visual markings along the length of the threaded portion to indicate to a user that the canister is being unscrewed. The sixth uses a canister with gas bleed channels formed on a threaded portion thereof. Several other variant embodiments of these three major embodiments are discussed below. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is a perspective view of a standard CO2 valve of the prior art. 
           [0008]      FIG. 2  is an exploded view of an elongated valve according to the present invention. 
           [0009]      FIG. 3  is an exploded view of an elongated valve according to a second embodiment of the present invention. 
           [0010]      FIG. 4  is a side elevation view of an elongated valve according to the second embodiment of the present invention. 
           [0011]      FIG. 5  is a perspective view of an elongated valve according to the second embodiment of the present invention. 
           [0012]      FIG. 6  is a top plan view of the elongated valve according to the second embodiment of the present invention. 
           [0013]      FIG. 7  is a sectional view of elongated valve according to the second embodiment of the present invention taken along line  7 - 7  in  FIG. 6 . 
           [0014]      FIGS. 8 and 9  show side views of a third alternate embodiment of the present invention. 
           [0015]      FIG. 10  shows an isometric view of a fourth alternate embodiment of the present invention. 
           [0016]      FIG. 11  shows an isometric view of a fifth alternate embodiment of the present invention. 
           [0017]      FIG. 12  shows an isometric view of a sixth embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0018]    As shown in  FIGS. 2-11 , a valve  30  generally comprises a threaded propellant interface portion  32 , a valve body  34 , a threaded portion  46 ,  146 ,  246 , and an axial hole  45  therethrough that runs between the interface portion  32  and the threaded portion  46 . A unified burst disk assembly  36  may also be provided, which screws into a threaded hole in the value  30 . Internally, the valve  30  comprises a depressor pin  40 , a depressor pin spring  42 , and a retainer plug  44 . 
         [0019]    A valve  30  according to a first embodiment of the present invention further comprises an elongated threaded portion  46  comprising a plurality of threads for securely engaging an air tank canister. The standard size valve  10  threaded portion  46  is preferably around ¾ inches long, as opposed to the longer threaded portion  46  in  FIGS. 2-7 , which is preferably 1.5 inches long. The elongated male threaded portion  46  engages the female threaded canister  50  over a longer distance, which means that removing the canister  50  takes longer. This longer duration for unscrewing the canister  50  minimizes the chance of fully removing the canister by accident. Even after a significant number of revolutions (turns) of a canister  50  with respect to the valve  30 , there will still be a number of engaged threads securing the valve  30  to the canister  50 . 
         [0020]      FIGS. 3-7  show a second embodiment of the invention used with the valve with the longer threaded portion. The valve  30  in  FIGS. 3-7  has a gas bleed channel  48  that extend to a terminal end  46   a  of the threaded portion  46  that provides an audible signal when the valve begins to unscrew from the canister  50 . This audible signal is from the compressed gas escaping from the canister  50  through the channel  48 . Further, this gas release, if not corrected quickly (by tightening the canister to the valve), will drain the compressed gas from the canister, and minimize the chance of unscrewing the canister  50  under pressure. 
         [0021]    The valve  30  comprises at least one gas bleed channel  48  along at least a portion of the length of the threaded portion  46 . The gas bleed channel  48  formed along a portion of the length of the elongated threaded portion  46 , indented below the upper edge  56  of the threads  47 . The gas bleed channel  48  may narrower adjacent the valve body  34 , as shown. Preferably at least two gas bleed slots are formed on opposite sides of the threaded portion  46 , as shown in  FIGS. 6 and 7 , although a plurality of gas bleed channel  48  may be provided. With multiple channels  48 , an even number of gas bleed channels  48  are formed in pairs on opposite sides of the threaded portion  46 . This opposed channel position allows compressed air to escape from the canister  25  evenly instead of only along one side of the threaded portion  46 , which might cock the canister  50  or release a lot of compressed gas through a single small channel  48  and separate the canister  50  from the valve  30 . 
         [0022]    In use, should the valve  30  begin to separate from an air tank canister  50  the upper portion of the gas bleed channel  48  will initially be exposed. As shown in  FIG. 7 , the channel  48  provides an escape for compressed gas in the canister  50  to follow the path indicated by the arrows. Escaping compressed gas should be audible and provide a warning that the valve  30  has begun to separate from the canister  50 . In the event that the marker user does not hear the escaping gas, the releasing gas will eventually depressurize the canister  50 , and minimize the chance of the canister  50  dislodging from the valve  30  under pressure. 
         [0023]      FIGS. 8 and 9  show a third embodiment using a standard size valve  130  with the bleed channel  148 , as opposed to the valve  30  with the longer threaded portion  46  shown in  FIGS. 2-7 . The advantage of the standard size valve  130  used with the gas bleed channel  148  is that it fits within all standard size valve accessories, including packaging, canisters, and other products that depend on valve size. 
         [0024]      FIG. 10  shows a fourth embodiment of the invention in which the valve has one or preferably several channels  248  located at different locations along the threaded portion  46 . These channels  248  serve the same purpose as the slots  48 ,  148 , in that they release air from the canister  50 . The channels  248  are preferably located at different positions around the circumference and along the length (distance from the terminal end  149  of the threaded portion  146 ) of the threaded portion  46 ,  146 , and optimally located so that pairs of the channels  248  are positioned on opposite sides of the threaded portion  146 . The channels  248  are preferably located so that at least one pair of channels  248  allows air to pass through from the canister through a channel  248  to the atmosphere at each position of the canister  50  as it is unscrewed. The advantage of the channels  248  is that they interrupt the threaded portion  46 ,  146  less than the longer channels  48 ,  148 . Further, multiple channels  248  will not likely all become blocked and rendered useless at once, whereas, if the channel  48 ,  148  becomes blocked, it is ineffective for releasing the compressed gas. 
         [0025]    In the fifth embodiment shown in  FIG. 11 , the elongated threaded portion  46  may be marked with a visible indicator  60 . For example, the threaded portion  46  may be colored in contrast to the valve body and/or canister, such that once a user sees the color “red”, by way of example, it is a visible indicator that the valve is coming away from the canister. In addition, should a color indicator be employed, the appearance of a contrasting color when the threads  18  become visible will provide a visual indicator as well. The use of different color bands  60 ,  62  along the threaded portion  46  could indicate the canister is becoming screwed, that is, when slightly unscrewed, the user sees yellow threads, further unscrewing shows orange threads, and the final threads engaging the canister  50  could be red. These indicators could all be color-coded to indicate the amount that the canister has been unscrewed, as discussed above. Further, although the channel  48  is shown as having the indicator  60  thereon, the indicator  60  could be marked on the threads  47  themselves, or on both the threads  47  and the channel  48 . 
         [0026]    The sixth embodiment shown in  FIG. 11  shows a canister  50  with channels  348  formed therein. This canister  50  would engage a standard or elongated threaded portion of a valve, and give an audible signal and release gas during unscrewing of the canister. 
         [0027]    The valve can be made of metal, plastic, ceramic or other suitable materials. Furthermore, the valve can be manufactured by casting, machining, injection molding, etc. The gas bleed slot can be formed during the casting or molding step as part of the mold. Alternatively, the gas bleed slot can be formed after casting by machining. 
         [0028]    The present invention is not limited to particular canisters, and the valve described herein may be used with any canister, such as those used in connection with fire extinguishers, propellant gas tanks, and the like. It is understood that the present invention is not limited to the particular embodiments shown and described herein, but that various changes and modifications may be made without departing from the scope and spirit of the invention.