Patent Document

RELATED APPLICATIONS 
     This application claims benefit of U.S. Provisional Patent Application No. 60/372,273 filed Apr. 12, 2002, which is incorporated herein by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to paintball loaders and, more particularly, to a detection system for controlling ball feed in a paintball loader. 
     BACKGROUND OF THE INVENTION 
     Popularity and developments in the paintball industry have led to the demand for increased performance from paintball guns. Paintball gun users usually partake in paintball war games. A paintball war game is generally played between two teams of players that try to capture the opposing team&#39;s flag. Each flag is located at the team&#39;s home base. Such a game is played on a large field with opposing home bases at each end. The players are each armed with a paintball gun that shoots paintballs. Paintballs are gelatin-covered spherical capsules filled with paint. 
     During the game, the players of each team advance toward the opposing team&#39;s base in an to attempt to steal the opposing team&#39;s flag. The players must do so without first being eliminated from the game by being hit by a paintball shot by an opponent&#39;s gun. When a player is hit by a paintball the gelatin capsule ruptures and the paint is splashed onto the player. As a result the player is “marked” and is out of the game. 
     These war games have increased in popularity and sophistication resulting in more elaborate equipment. One such improvement is the use of semi-automatic and automatic paintball guns which allow for rapid firing of paintballs. As a result of the increased firing speed, a need has developed for increased storage capacity of paintballs in the paintball loaders that are mounted to the gun. Also, users demand faster feed rates as the guns continue to develop. 
     Paintball loaders typically include a housing that sits on an upper portion of a paintball gun and which is designed to hold a large quantity of paintballs. There is an outlet tube at the bottom of the housing through which the paintballs drop by the force of gravity. The paintballs pass into an inlet tube located in the upper portion of the gun. 
     In use, paintballs fall sequentially through the outlet tube into the inlet of the gun. The inlet tube directs each paintball into the firing chamber of the gun where the paintball is propelled outwardly from the gun by compressed air. Because existing paintball loaders rely on the force of gravity to feed the paintballs to the gun, they function properly to supply paintballs only if the gun and the loader are held in a substantially upright position. If, during a game, a player is forced to hold the gun sideways or upside down, the loader will not function properly. 
     Furthermore, it is not uncommon that, while feeding paintballs to the gun, the paintballs jam in the gun. In order to correct the problem, the player may shake the gun or strike the loader in order to dislodge the jammed paintball. This obviously places the player at risk during the game since the player is distracted by the need to adjust the equipment. 
     Currently there are on the market paintball loaders that utilize an optical sensor mounted within the loaders to detect the absence of a paintball in the infeed tube of a paintball gun. When the sensor detects that there is no paintball in the infeed tube of the paintball gun, a motor is activated which causes a paddle to force a paintball into the paintball gun. Other conventional paintball loaders utilize agitators having sound sensors to sense a gun firing event. In response to the sound of the gun firing, an electrical signal is sent to activate an agitator which moves a paintball into the feed tube. 
     While recent feed systems are an improvement over the prior feeders, the current feed systems are complicated and costly to manufacture. Such systems may also lead to jamming. 
     There is, therefore, a need for a feed mechanism for a feed system that simply and reliably feeds paintballs to a paintball gun at a high rate, while at the same time prevents or reduces the likelihood of paintball jams. There is also a need for a paintball loader which controls the feed motor so as to prolong battery life and reduce undesirable noise. 
     SUMMARY OF THE INVENTION 
     In one aspect, the present invention is a ball feed mechanism for use in a paintball loader. The ball feed mechanism includes a feeder for feeding paintballs. The feeder may be a drive cone, paddle wheel, or indexing belt, which has protrusions, recesses or paddles that convey or impel balls toward a feed neck. The feed mechanism also preferably includes a drive shaft which is concentric with the feeder. The feeder mounts on the drive shaft and is free to rotate about the drive shaft before engaging mechanical stops. The feeder is coupled to the drive shaft through a spring. The spring is configured to store potential energy which is used to rotate the feeder and, thus, drive the balls toward the feed neck. An electric motor is used to rotate the drive shaft to wind or compress the spring. 
     In operation the spring is normally compressed so that the spring energy is always available to impel balls toward the feed neck as required. The motor is energized as needed to restore the spring energy (e.g., through compression of the spring). Other resilient members, such as elastomers, may be used in place of the spring. 
     The feed mechanism includes an indexing mechanism which includes a sensor, for example, to determine the degree of tension or winding of the spring. In one embodiment, the indexing mechanism accomplishes this by using the sensors to detect rotational movement of the feeder and a drive mechanism (which includes the drive shaft). A controller is in communication with the sensors and determines the relative position of the feed mechanism to the drive mechanism for determining whether the spring requires winding. The relative position of the feeder and drive mechanism can be correlated with the degree of compression/tension of the spring. If the controller determines that the spring requires winding, a motor is activated, causing the drive mechanism to rotate. This, in turn, causes the spring to wind. 
     The feed mechanism may alternately include a tensionometer or a strain gauge in communication with a controller. These devices are used to determine the state of deflection of the spring. If the controller determines that additional deflection of the spring is required, the controller will actuate a motor which rotates the drive mechanism and the spindle. The rotation of the spindle, in turn, causes the spring to compress or tension. 
     The foregoing and other features of the invention and advantages of the present invention will become more apparent in light of the following detailed description of the preferred embodiments, as illustrated in the accompanying figures. As will be realized, the invention is capable of modifications in various respects, all without departing from the invention. Accordingly, the drawings and the description are to be regarded as illustrative in nature, and not as restrictive. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing summary, as well as the following detailed description of the invention, will be better understood when read in conjunction with the appended drawings. In the drawings: 
         FIG. 1  is a side elevational view of a rapid feed paintball loader constructed in accordance with the teachings of the present invention and operatively attached to a representative paintball gun illustrated in phantom; 
         FIG. 2  is an exploded upper isometric view of one embodiment of the loader according to the present invention; 
         FIG. 3  is an exploded lower isometric view of the embodiment of the loader shown in  FIG. 2 ; 
         FIG. 4  is a lower isometric view of the embodiment of the loader shown in  FIG. 3 ; 
         FIG. 5  is an exploded upper isometric view of a second embodiment of the loader according to the present invention; 
         FIG. 6  is a side view of the loader of  FIG. 5 ; 
         FIG. 7  is a top view of an alternate feeder according to the present invention; 
         FIG. 8  is a top view of yet another feeder according to the present invention; 
         FIG. 9  is a schematic of a controller according to the present invention. 
         FIG. 10  illustrates a pulley mechanism for driving the drive shaft in accordance with an alternate embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings wherein like numerals indicate like elements throughout, there is shown in  FIG. 1  a side elevational view of paintball loader  40  in accordance with the present invention and operatively attached to a representative paintball gun  20 , illustrated in phantom. The paintball gun  20 , includes a main body  22 , a compressed gas cylinder  24 , a front handgrip  26 , a barrel  28 , and a rear handgrip  30 . The paintball gun  20  also includes an inlet tube  32 , leading to a firing chamber (not shown) in the interior of the main body and a trigger  34 . The front handgrip  26  preferably extends downwardly from the barrel  28  and provides a grip. The compressed gas cylinder  24  is typically secured to a rear portion of the paintball gun  20 . The compressed gas cylinder normally contains CO 2 , NO 2  or air, although other gases may also be used. 
     In using the paintball gun  20 , trigger  34  is squeezed, thereby actuating the compressed gas cylinder to release controlled bursts of compressed gas. The bursts of gas are used to eject paintballs outwardly through the barrel  28 . The paintballs are continually fed by the paintball loader  40  through the inlet tube of the firing chamber. The paintball gun depicted in  FIG. 1  is an automatic paintball gun, however the gun may also be semi-automatic. 
     The paintball loader  40  comprises a paintball container  42  having a container wall  44  forming an interior area  46 . The container has an upper portion  48  and a lower portion  50 . An exit tube  52  leads from the lower portion of the container to an outlet opening  54 . The exit tube is positioned on top of the inlet tube  32  of the paintball gun  20 . A feed mechanism  100  (shown in  FIG. 2 ) is used to drive or urge the paintballs toward the exit tube and into the inlet tube  32 . 
       FIG. 2  is an exploded isometric view of one embodiment of the feed mechanism  100  according to the present invention. While a preferred feed mechanism  100  is shown, various other components may be substituted therefore for driving paintballs into the paintball gun  20 . The feed mechanism  100  includes a feeder  102  which drives or otherwise conveys paintballs into the exit tube  52 , and a drive mechanism  500 . 
     A variety of feeders  102  can be used in the present invention, including an impeller, drive cone, paddle wheel, carrier or other device which can direct or otherwise urge paintballs from the loader into the exit tube  52 . One preferred feeder  102  is shown in the figures and includes a housing  103  with a plurality of fins  104  which preferably extend in a radial direction from the housing  103 . While the fins  104  are shown as being straight, other shapes can be used as will be discussed below. The feeder  102  also preferably includes flanges  105  that extend between adjacent fins  104 . As should be apparent from the drawings, the housing, fins and flanges can be made as a single injection molded part. While fins are shown, it is also contemplated that the feeder may include recesses within which the paintballs sit as they are shuttled toward the exit tube. 
     A cylindrical opening  106  is formed in the center of the housing  103  for receiving a fastener  130 . The fastener  130  is used to engage or mount the feeder  102  to a drive shaft or spindle  108  of the drive mechanism  500 . More particularly, the fastener  130  extends through the opening  106  and threads into a hole formed in the top of the drive shaft  108 . 
     Referring now to  FIG. 3 , the bottom of the feeder  102  is shown in more detail. The housing  103  includes a first flange  124  which is attached to and projects downward from the housing  103 . In the illustrated embodiment, the first flange  124  is formed integral with the housing  103 . The first flange  124  is designed to engage with a first end of a spring  116  as will be better understood hereafter. 
     As shown in  FIGS. 3 and 4 , the drive mechanism  500  includes a spring housing  112  which is disposed about the drive shaft  108  and is positioned so as to be below the feeder  102 . The spring housing  112  includes an outer wall  113  and a bottom wall  115 . An inner wall  117  is formed about a central opening  119 . The drive shaft  108  is designed to pass through the central opening  119  and engage with the spring housing  112  such that rotation of the drive shaft  108  produces concomitant rotation of the spring housing  112 . In the illustrated embodiment, a portion of the drive shaft  108  is shown non-cylindrical in shape and the opening  119  is formed with a mating non-cylindrical shape. A spring clip  132  or similar fastener is preferably used to restrain vertical movement of the spring housing  112  on the drive shaft  108 . This is more clearly illustrated in  FIG. 4  which shows the spring housing  112  mounted to the drive shaft  108 . 
     A second flange  120  is attached to or, more preferably, formed integral with the spring housing  112 . The second flange  120  is configured to engage with a send end of the spring  116 . 
     The inner wall  117  and outer wall  113  define a spring chamber  114  within the spring housing  112 . A spring or other biasing member  116  is located within the spring chamber  114 . Although a spring is shown in the figures, it should be readily apparent that other biasing members, such as elastomers, could instead be used. The spring  116  is preferably a torsion spring. A first leg  150  on the first end of the spring  116  is adapted to engage with the first flange  124  on the feeder  102 . A second leg  152  on the second end of the spring is adapted to engage with the second flange  120  on the spring housing  112 . As such, the spring  116  is mounted so as to bias the feeder  102  against rotation relative to the spring housing  112 . In other words, rotation of the spring housing  112  relative to the feeder  102  produces deflection or winding of the spring  116 . When the spring is rotated in the direction which produces winding of the spring, the rotation creates a restoring force (potential energy) in the spring which attempts to counter-rotate the spring housing  112  relative to the feeder  102 . As should be readily apparent, if the feeder  102  is unrestrained, rotation of the spring housing will produce concomitant rotation of the feeder  102 . It is only when there is something which inhibits rotation of the feeder  102  (such as paint balls already in the exit tube) that the spring housing  112  will wind the spring  116 . 
       FIG. 4  illustrates the assembled feeder  102 , spring housing  112 , and the drive shaft  108 . The drive shaft  108  projects downward from the spring housing  112  and is adapted to engage with a drive member or gear that is part of the drive mechanism  500 . 
     Extending downward from the lower surface of the feeder  102  is at least one and, more preferably, a plurality of spaced apart upper indexing teeth  160 . The upper indexing teeth  160  are preferably spaced in a circular pattern about the bottom of the feeder  102 . As will be discussed below, the upper indexing teeth  160  are used in combination with a sensor to determine the rotational position of the feeder  102 . The indexing teeth  160  are preferably formed integral with or attached to the feeder  102 . While indexing teeth are shown in the illustrated embodiment, other indexing members, such as reflectors, markers, recesses, etc, may be used. 
     Referring back to  FIGS. 2 and 3 , one embodiment of the drive member  508  is shown. In this embodiment, the drive member  508  is a drive gear includes a plurality of spaced apart gear teeth  503  formed about the periphery of the drive gear  508 . The teeth  503  of the drive gear  508  are adapted to engage with mating teeth on a second gear connected to a motor  99 . While the drive member  508  in the illustrated embodiment is a gear, other types of conventional drive members can be used to produce controlled rotation, such as a pulley mechanism or stepper motor. A pulley mechanism is shown in FIG.  10 . The pulley  508  is engaged to the motor  95  through a belt  99 . 
     The drive member  508  also includes at least one and, more preferably, a plurality of lower indexing members  510  formed on the drive gear  508  and preferably on its lower surface. As with the upper indexing teeth  160 , the lower indexing members  510  are used to determine the position of the drive gear  508  and, thus, the spring housing  112 . While the indexing members are shown as protrusions in the illustrated embodiment, other indexing members, such as teeth, reflectors, markers, recesses, etc, may be used. 
     The feed mechanism  100  also includes a first indexing sensor positioned below and preferably adjacent to the lower surface of the feeder  102 . The first indexing sensor  504  is located so as to be able to detect or otherwise sense the upper indexing teeth  160 . More particularly, as the feeder  102  rotates around its central axis, the sensor  504  detects the upper indexing teeth  160  as they pass the sensor. The number of passing teeth  160  that is sensed (e.g., over a prescribed period) is used to determine the rotational motion of the feeder  102 . As should be readily apparent, the more upper indexing teeth  160  that are formed on the feeder  102 , the more accurate the position of the feeder  102  can be determined. A signal is sent from the sensor indicative of the sensed number of passing teeth. Alternatively, the sensor  504  may be a ratcheting mechanism that supplies the controller with a signal after the ratchet has rotated a predetermined number of times or amount. 
     A second indexing sensor  506  is mounted adjacent to the drive gear  508  so as to be able to detect the passing of the lower indexing members  510 . The rotational motion of the drive gear  508  and, thus, the spring housing  112 , is determined by counting the number of passing lower indexing members  510 . A signal is sent from the sensor indicative of the sensed number of passing teeth. While the illustrated embodiment depicts the sensor and indexing members as being mounted to the drive gear, it should be readily understood that the sensor can be mounted so as to detect rotational motion of the drive shaft. 
     Referring to  FIG. 9 , the first indexing sensor  504  and second indexing sensor  506  are in communication with a controller  900 , such as a computer or microprocessor (not shown). The controller  900  determines the position of the feeder  102  relative to the drive gear  508  and evaluates whether the spring  116  requires tensioning (winding) or deflection. If the controller  900  determines that the spring  116  requires tensioning, the controller will actuate a motor  950  which is engaged with the drive gear  508  to rotate the drive gear  508  a desired amount. The engagement is preferably through a drive system  960 , such as a gear that meshes with the teeth  503  on the drive gear  508 . Rotation of the drive gear  508 , in turn, rotates the drive shaft  108  and, thus, the spring housing  112 . The rotation of the spring housing  112  relative to the feeder  102  causes the spring  116  to wind, preferably until the second flange  120  meets the first flange  124 . 
     During operation, as the feeder  102  advances the paint balls into the gun, the first sensor  504  counts the number of upper indexing teeth  160  that have passed and provides a signal to the controller. The second sensor  506 , likewise, counts the number of lower indexing members  510  that have passed and provides a signal indicative thereof to the controller. It is envisioned that, during firing, the drive gear  508  may not necessarily be moving. Instead, only after the controller  900  detects that the positional location of the feeder  102  relative to the drive gear  508  correlates to a spring that needs “rewinding” would the controller  900  send a signal to the motor  950  to rotate the drive gear  508 . For example, the system may be set such that only after half of the paintballs are dispensed that can be held by the feeder is the motor activated to rotate the drive gear  508 . 
     Alternately, the controller  900  can continuously monitor the movement of the feeder  102  and the drive gear  508 . Any movement of the feeder  102  relative to the drive gear  508  can result in the motor rotating the drive gear  508  to rewind the spring. Thus, the gun will always be set to feed the maximum number of balls possible using the feeder. 
     The controller  900  may also be programmed to rotate the drive gear  508  a prescribed distance to wind the spring, thus preventing overwinding. The lower indexing members  510  can be tracked through the second sensor  506  to stop the rotation of the drive gear  508  when desired. For example, the controller may be programmed to tension the spring a sufficient amount to feed 10 paintballs into the gun before needing to be rewound. Upon firing of the gun, tension of the spring will feed the 10 paintballs into the exit tube. The controller determines the number of balls to be fed from the data provided by the first indexing sensor  504 . 
     Alternatively, the present invention may utilize only one sensor to detect the movement of the impeller. A motor, such as a stepper motor, can be used to incrementally wind the spring for every detected movement of the impeller. For example, if the spring has a tension sufficient to feed 10 paintballs, for every ball that the sensor detects as being fed by the feeder, the motor will wind the spring by {fraction (1/10)} th  of the complete rotation. 
     It is also contemplated that the controller may be used to detect whether there are any paintballs in the exit tube. If the controller  900  determines that there are no paintballs in the tube, that would indicate that the spring is in an unwound condition. Thus, the controller  900  would activate the motor  950  and rewind the spring. 
     An alternate embodiment of the sensor mechanism is shown in FIG.  5 . In this embodiment, the first sensor includes a first emitter  602  and a first receiver  604 . The first emitter  602  provides a beam that is reflected by reflectors placed around the periphery of the underside of feed cone  102 . The reflected signal is detected by receiver  604 . Although depicted separately for clarity, the emitter  602  and receiver  604  may be housed in the same unit. The beam may be an infrared (IR) beam. Likewise a second emitter  606  and a second receiver  608  are provided in lieu of second indexing sensor  506 . The second emitter  606  provides a beam that is reflected by reflectors placed around the periphery of the top or underside of drive gear  508 . The reflected beam is detected by second receiver  608 . The emitter  606  and receiver  608  may be housed in the same unit, or mounted separate as shown. The first and second emitters/receivers are in communication with the controller  900 .  FIG. 6  illustrates the assembled unit of FIG.  5 . 
     It is also contemplated that the sensing mechanism may instead include a tensionometer or strain gauge  93  (shown in dashed lines in  FIG. 2 ) to determine the tension of the spring. The strain gauge would be in communication with the controller. If the tension in the spring falls below a preselected limit, the controller will actuate the motor which rotates the drive mechanism that in turn rotates the spindle, thereby tensioning the spring. 
     Referring to  FIGS. 7 and 8 , alternate feeder arrangements are shown. More particularly,  FIG. 7  illustrates a feeder  200  which includes two fins  202 . The fins are spaced 180 degrees apart, thus permitting a plurality of balls  206  to be located between adjacent fins  202 .  FIG. 8  illustrates a feeder with a plurality of curved fins  302 , each one designed to cup an individual paintball  206 . Those skilled in the art would be readily capable of substituting alternate design configurations for the feeder in order to effect sufficient feeding of the desired number of paint balls. 
     The present invention provides a novel system for feeding paintballs from a container. The use of a two sensors permits controlled feeding which is not possible with conventional feeders. The controller in the present invention can be adjusted to minimize use of the motor, thereby conserving battery power. The controller can also be used to accurately track the amount of balls dispensed. 
     Furthermore, the controller in the present invention can also be controlled so as to vary the tension and pressure applied to the ball supply. The feed mechanism can include a user input mechanism, such as a dial or pushbuttons, which permits the user to adjust when the drive mechanism re-winds the spring. 
     While the potential energy caused by the spring has been described as resulting from winding the spring, it should be readily apparent that a compression spring can be used, in which case the winding of the spring should be understood to refer to a compression of the spring to build up a restoring force or potential energy. 
     The present invention may be embodied in other specific forms without departing from the spirit thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification, as indicating the scope of the invention. 
     Although preferred embodiments of the sensors have been described and shown in the drawings, those skilled in the art will understand how features from the two embodiments may be combined and interchanged.

Technology Category: f