Abstract:
A paintball gun preferably includes an adjustable, clamping feed tube. The feed tube can, for instance, include a lever for closing and opening a clamp, thereby tightening or loosening a receiving end of a feed tube to secure or release a hopper neck. The feed tube also preferably includes a finger adjustable nut for adjusting the size of the receiving end to accommodate differently sized hopper necks.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates generally to feed tubes for connecting paintball hoppers (or loaders) to a paintball gun, and more particularly to adjustable and clamping feed tubes for paintball guns.  
         [0003]     2. Description of Related Art  
         [0004]     Conventional feed tubes are typically attached to a paintball gun by screwing a threaded portion of the feed tube into a receiving hole arranged near the breech end of the paint ball gun. Feed tubes provide a connection between a paintball hopper (or loader) and the paintball gun to permit paintballs from the hopper to feed into the breech of the paintball gun for launching. Hoppers typically include a storage chamber, a lid, and a neck. The neck is typically a hollow tube that fits into a receiving end of the feed tube, located opposite the threaded portion of the feed tube. The hollow portion of the hopper neck must be large enough to accommodate a paintball, which is typically about 0.68 inches in diameter. Unfortunately, however, there is no universally accepted standard for the outside diameter of the hopper neck and there is therefore variation between different hopper models.  
         [0005]     More conventional feed tubes have included non-adjustable receiving ends, having a neck opening of a predetermined (fitted) size. Feed tubes with non-adjustable receiving ends rely on frictional engagement between the hopper and the feed tube to secure the hopper to the paintball gun. Although effective in situations where the hopper neck and feed tube opening have closely mating sizes, non-adjustable feed tubes often do not properly secure a hopper. If, for example, either the size of the hopper neck or the size of the fitted receiving end changes due to changes in temperature, the hopper may not be properly secured to the paintball gun. If the frictional engagement is not secure enough, the hopper neck may slip out of the fitted receiving end as a player moves or turns his paintball gun. Furthermore, hoppers are generally plastic, and thus the hopper flange may be easily damaged or worn out by repeated insertions and removals. Damage to the hopper neck negatively impacts its ability to properly engage with the fitted receiving end of the feed tube. And because many standards exist for hopper neck sizes, fitted receiving ends are incompatible with many hoppers.  
         [0006]     More recently, various manufacturers have introduced feed tubes having adjustable receiving ends. Feed tubes with adjustable receiving ends generally allow a hopper flange to attach to a receiving end more securely than do fitted receiving ends. This more secure, adjustable fit solves many of the problems associated with pre-sized receiving ends, including the problems described above. However, conventional feed tubes with adjustable receiving ends often require tools to adjust a receiving end to release or secure a hopper. The use of tools requires a user to spend more time removing and securing the hopper, such as when setting up or putting away their equipment, or when clearing a jammed firing chamber. Additionally, the user needs to carry tools that may get lost during game play. The requirement for tools for securing and releasing a hopper is therefore undesirable to a paintball user both because of the time requirements and because it requires the user to carry and risk dropping and losing the appropriate tools.  
         [0007]     Although feed tube designs have been introduced that do not require tools for adjustment, these do not typically provide as much clamping force as those that use tools. Twist-lock feed tube designs, for instance, where a user adjusts the size of the feed tube by twisting an outer portion of the feed tube, have become fairly common. The action required to tighten or release a twist-lock feed tube may also be time consuming depending on the number of turns required to adjust the tube to the appropriate size.  
         [0008]     The paintball gun industry is in need of an adjustable feed tube that can be quickly resized to accommodate hoppers designed to different standards while providing sufficient clamping force. Users desire the ability to quickly and securely accommodate hoppers of different neck sizes without the use of tools. Various aspects and embodiments of the present invention address these and other problems associated with conventional feed tube designs.  
       SUMMARY OF THE INVENTION  
       [0009]     According to one embodiment of the present invention, a clamping feed tube preferably comprises a clamping feed neck and a lever. Clamping pressure is preferably released when the lever is moved away from the feed neck and applied as the lever is moved toward the feed neck. This can be accomplished, for instance, by providing the lever with a rounded base in communication with a clamping surface. The rounded base is preferably disposed around a pivot point. The pivot point is preferably arranged through the lever to provide a narrow portion of the rounded base that gradually widens into a wider portion. The narrow portion is preferably in contact with the clamping surface when the lever is in a released (open) position, with the wider portion in contact with the clamping surface when the lever is in a clamped (closed) position. The lever is further preferably configured to remain biased in its open and closed positions until an operator applies force to the lever to move it to the opposite position. Operation of the lever preferably does not require the use of tools.  
         [0010]     According to another embodiment of the present invention, an adjustable feed tube preferably comprises an adjustable feed neck and a finger adjustable nut. The finger adjustable nut is preferably turned to adjust the size of a receiving opening of the feed tube. This can be accomplished, for instance, by threading the nut onto a bolt arranged through openings on opposing tabs. The tabs may be arranged on opposite ends of a gap formed between opposite sides of the feed neck. Adjustment of the finger adjustable nut preferably widens or narrows the gap between the tabs and thereby adjusts the size of the receiving opening of the feed tube. Operation of the finger adjustable nut preferably does not require the use of tools.  
         [0011]     According to still another embodiment of the present invention, a clamping feed tube preferably comprises a clamping feed neck, a finger adjustable nut, and a lever. The finger adjustable nut is preferably connected to the lever to permit adjustment of the size of a receiving opening of the feed tube. Clamping pressure is preferably released when the lever is moved away from the feed neck and applied as the lever is moved toward the feed neck. This can be accomplished for instance, by providing the clamping feed neck with a gap arranged between opposing tabs. The finger adjustable nut is preferably arranged on a threaded end of a bolt disposed through openings in the tabs. Adjustment of the finger adjustable nut preferably adjusts the size of the gap and hence the size of the receiving opening.  
         [0012]     The lever preferably comprises a rounded end disposed around a pivot point on an end of bolt opposite the threaded end. The rounded end of the lever preferably includes a narrow portion that gradually extends into a wider portion. The narrow portion is preferably in contact with the clamping surface when the lever is in an open position, with the wider portion in contact with the clamping surface when the lever is in a closed position. The lever preferably remains biased in its open and closed positions until a user applies force to the lever to move it to the opposite position. A textured gripping surface may also be provided on the inside surface of the clamping feed neck to grip the outside of a hopper neck.  
         [0013]     This embodiment is particularly useful because of the combination of the finger adjustable nut and lever. The lever operated clamp can be used to release clamping pressure and permit the finger adjustable nut to be readily operated while the clamp is in the open position. This makes the finger adjustable nut easy to adjust even when a user&#39;s fingers are slippery with paint. This thereby permits easy clamping and release of the feed tube without the use of tools, even with slippery hands. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]     The foregoing and additional objects, features, and advantages of the present invention will become more readily apparent from the following detailed description of preferred embodiments thereof, made with reference to the accompanying figures, in which:  
         [0015]      FIG. 1  is a perspective view of an adjustable, clamping feed tube according to a preferred embodiment of the present invention, shown with a clamp in a closed position;  
         [0016]      FIG. 2  is a perspective view of the adjustable, clamping feed tube of  FIG. 1 , shown with the clamp in an open position;  
         [0017]      FIG. 3  is a top plan view of the adjustable, clamping feed tube of  FIG. 1 ;  
         [0018]      FIG. 4  is a top plan view of the adjustable, clamping feed tube of  FIG. 1 , shown with the clamp in an open position;  
         [0019]      FIG. 5  is a bottom plan view of the adjustable, clamping feed tube of  FIG. 1 ;  
         [0020]      FIG. 6  is a perspective view of a clamping member of the feed tube of  FIG. 1 ;  
         [0021]      FIG. 7  is a perspective view of a feed neck of the feed tube of  FIG. 1 ;  
         [0022]      FIG. 8  is a perspective view of a bolt, nut, pin, and bushing assembly of the feed tube of  FIG. 1 ;  
         [0023]      FIG. 9  is a perspective view of a bolt, bushing, and pin assembly of the feed tube of  FIG. 1 ; and  
         [0024]      FIG. 10  is a perspective view of a bolt, nut, pin, bushing, and lever assembly of the feed tube of  FIG. 1 .  
     
    
     DETAILED DESCRIPTION  
       [0025]      FIG. 1  is a perspective view of an adjustable, clamping feed tube  10  according to a preferred embodiment of the present invention, showing a clamp  13   a  in the closed position.  FIG. 2  is a perspective view of the adjustable, clamping feed tube  10  of  FIG. 1 , showing the clamp  13   a  in an open position.  FIGS. 3-5  are various views of the feed tube  10  of  FIG. 1 , illustrating the clamp  13   a  in both open and closed positions.  FIGS. 6-10  are perspective views of various components of the adjustable, clamping feed tube  10  of  FIG. 1 , giving a more detailed understanding of various principles of the present invention.  
         [0026]     Referring to  FIGS. 1-10 , the adjustable, clamping feed tube  10  includes a threaded portion  11  that provides a threaded engagement with a paintball gun (not shown). A receiving end  12  is located opposite the threaded portion  11  to receive a hopper neck (not shown). An opening in the receiving end  12  can be quickly enlarged by opening a clamping member  13   a . The clamp  13   a  is preferably opened by moving the lever  15  away from the feed tube  10 . A lever is preferable because it allows for a consistent clamping force and because it is easy to operate without tools, even with slippery, paint covered hands.  
         [0027]     The clamping member  13   a  is preferably formed having, cylindrical tube-like structure with a gap  22  arranged between two opposing tabs  24   a ,  24   b . The clamping member  13   a  further preferably includes a lip  26  arranged on an upper end. The opposing tabs  24   a ,  24   b , preferably each include an opening for receiving a bolt  16 .  
         [0028]     The clamping member  13   a  is preferably arranged around a feed neck  13   b . The feed neck  13   b  preferably comprises an upper receiving portion  30  for receiving a hopper and a lower attachment portion  32  for attaching to a paintball gun. The upper receiving portion  30  is preferably formed as a cylindrical tube  30   a  having a plurality of longitudinal slits  30   b  formed therein to permit flexing of the tube  30   a  and thereby also permitting resizing of the opening in the receiving portion  30 . The attachment portion  32  preferably includes the threaded section  11 .  
         [0029]     The finger adjustable nut  14  is preferably arranged on a threaded end  16   b  of a bolt  16  disposed through openings in the tabs  24   a ,  24   b . Adjustment of the finger adjustable nut  14  preferably adjusts the size of the gap  22  and hence the size of the opening in the receiving portion  30 .  
         [0030]     The lever  15  preferably comprises a rounded end  15   a  disposed around a pivot point  19  located on an end of bolt  16   a  opposite the threaded end  16   b . A bushing  17  is preferably disposed between the rounded end  15   a  of the lever  15  and the tab  24   a . The rounded end  15   a  of the lever  15  preferably includes a narrow portion  15   c  that gradually expands into a wider portion  15   d . The narrow portion  15   c  is preferably in contact with the tab  24   a  when the lever  15  is in an open position, with the wider portion  15   d  in contact with the tab  24   a  when the lever  15  is in a closed position. Accordingly, as the lever  15  is moved from an open to a closed position, the rounded portion  15   a  of the lever  15  applies force against the tab  24   a , reducing the size of the gap  22  and applying a clamping force on the feed neck  13   b  through the clamping member  13   a.    
         [0031]     The lever  15  preferably remains biased in its open and closed positions until a user applies force to the lever  15  to move it to the opposite position. The lever  15  is preferably curved to rest flush with the outer surface of the clamping member  13   a . A retaining member  20  can be provided on the outer wall of the clamping member  13   a  to prevent the lever from rotating about the axis of the bolt  16  and nut  14  (i.e. threading), which in turn prevents possible increase or decrease in clamping force.  
         [0032]     The lever  15  preferably includes a gripping end  15   b  bent outwardly from the clamping member  13   a  to permit easy gripping and operation of the lever  15 . A textured gripping surface  34  may also be provided on the inside surface of the clamping feed neck  13   b  to grip the outside of a hopper neck.  
         [0033]     After the clamp  13   a  has been opened, the size of the opening in the receiving end  12  can be further adjusted, preferably by turning the finger adjustable nut  14 . Adjustment of the opening size may be useful to adapt the feed tube  10  to securely receive a hopper with a larger or smaller hopper neck. The finger adjustable nut  14  may, for instance, be tightened to secure a hopper with a smaller neck and loosened to accept a hopper with a larger neck. The finger adjustable nut  14  also preferably includes an Allen wrench socket  14   a  to permit adjustment with an Allen wrench, if desired.  
         [0034]     In operation, the lever  15  is preferably moved outwardly from the feed tube  10  to enlarge the opening in the receiving end  12 . The finger adjustable nut  14  is preferably adjusted to cause the opening in the receiving end to approximately match the outside diameter of a desired hopper neck. After (or before) the finger adjustable nut  14  has been adjusted to accommodate the hopper neck, the hopper is inserted into the opening in the receiving end  12 . The clamp  13   a  is then closed via operation of the lever  15  (e.g., by pushing the lever  15  towards the feed tube  10 ), to secure the hopper in the feed tube  10 , and hence to the paintball gun.  
         [0035]     Various alternative embodiments of the present invention are also contemplated. For instance, one embodiment may include a lever-operated clamp without the use of a finger-adjustable nut. Yet another embodiment may comprise the use of a finger-adjustable nut without the use of a lever-operated clamp. Still other variations on the concepts disclosed herein will be apparent to those skilled in the art.  
         [0036]     Having described and illustrated the principles of the invention in a preferred and various alternative embodiments thereof, it should be apparent that the invention can be modified in arrangement and detail without departing from such principles. All such modifications and variations come within the spirit and scope of the following claims.