Abstract:
The present invention provides a trigger assembly for a paintball marker utilizing compressed gas. The trigger assembly includes an air assist trigger mechanism further providing exhaust gas to a ram assembly for recocking the paintball marker.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   Not Applicable. 
   STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
   Not Applicable. 
   REFERENCE TO A MICROFICHE APPENDIX 
   Not Applicable. 
   RESERVATION OF RIGHTS 
   A portion of the disclosure of this patent document contains material which is subject to intellectual property rights such as but not limited to copyright, trademark, and/or trade dress protection. The owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure as it appears in the Patent and Trademark Office patent files or records but otherwise reserves all rights whatsoever. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to the field of paintball markers. In particular, the present invention relates specifically to a ram used for controlling the back block of a paintball marker. The ram provides pressure relief at the end of the ram&#39;s internal piston tube to reduce operating resistance and provide increased operating speed for the marker. 
   2. Description of the Known Art 
   The equipment used to fire paint balls are commonly referred to as paintball “markers”. Markers launch the paint balls by releasing a burst of compressed gas (typically CO2, N2, or air) into a barrel behind the paintball projectile. Projectile launchers operated by means of a supply of pressurized gas have been known for quite some time and have been used to fire a variety of projectiles including pellets and small balls. In more recent years, gas operated markers have been developed and designed specifically to fire paint balls. The paint balls typically may comprise a mixture of a liquid including ethylene glycol with the liquid being encased in a fragile gelatin casing designed to break apart upon striking a target. The liquid will then mark the target that has been hit. These types of markers have a variety of different uses. Earlier uses involved tree marking in forestry projects and animal marking in conservation or farming projects. For example, the markers were originally used to segregate livestock within a herd, assist in the counting of wild animals or for training of military or law enforcement personnel through simulation exercises. Likewise, these markers may be used by military and law enforcement personnel for crowd control. 
   Another very popular use for such markers is recreation in the game of “paintball”. In particular, paintball markers are used for “mock war games” in which participants dressed in protective gear attempt to hit other combatants with paint balls thereby marking them and eliminating them from the game. 
   As will be appreciated by those skilled in the art, a variety of different types of paint ball markers exist in the field using a variety of mechanisms for accomplishing their purpose of projecting paint balls. Patents disclosing information relevant to paintball markers include U.S. Pat. No. 3,788,298, issued to Hale on Jan. 29, 1974; U.S. Pat. No. 4,147,152, issued to Fisher et al. on Apr. 3, 1979; U.S. Pat. No. 4,531,503, issued to Shepard on Jul. 30, 1985; U.S. Pat. No. 5,462,042, issued to Greenwell on Oct. 31, 1995; U.S. Pat. No. 5,505,188, issued to Williams on Apr. 9, 1996; U.S. Pat. No. 5,515,838, issued to Anderson on May 14, 1996; U.S. Pat. No. 6,439,217, issued to Shih on Aug. 27, 2002; U.S. Pat. No. 6,553,983, issued to Li on Apr. 29, 2003; U.S. Pat. No. 6,561,176, issued to Fujimoto et al. on May 13, 2003; U.S. Pat. No. 6,578,566 issued to Hernandez on Jun. 17, 2003; U.S. Pat. No. 6,658,982 issued to Cherry on Dec. 9, 2003; U.S. Pat. No. 6,637,420, issued to Moritz on Oct. 28, 2003; and U.S. Pat. No. 6,715,480 issued to Dziob on Apr. 6, 2004. The entirety of each of these patents is hereby expressly incorporated by reference. 
   U.S. Pat. Nos. 3,788,298; 4,147,152; 4,531,503; and 5,505,188 are typical of paint ball markers wherein the hammer and/or bolt are in a single barrel. 
   U.S. Pat. Nos. 5,462,042; 5,515,838; 6,553,983; and 6,561,176 are typical of paintball markers wherein the marker body comprises two parallel tubular bores. The upper bore contains the bolt, while the lower bore contains the hammer. The bolt and hammer components are connected together, allowing their moving parts to move in concert. The bolt and hammer assembly is held in the reset position via a trigger sear, which catches the hammer portion of the assembly. In this position the breach is open and a paint ball is able to drop into position in front of the bolt. When the trigger is pulled the sear releases the hammer and a spring drives the hammer and bolt forward. As the bolt moves forward the hammer simultaneously moves forward to strike a poppet valve as the bolt closes on the chamber. The poppet valve releases a burst of high pressure gas into and through the bolt expelling the paint ball from the barrel. A bleed-off of the burst of high pressure gas then propels the hammer and bolt backwards. The hammer is then caught by the trigger sear and the marker is again in a reset configuration and ready to be fired again. 
   Another form of marker using two parallel tubular bores is shown in U.S. Pat. No. 6,637,420 wherein the hammer and bolt operate independently of each other. One attribute which is extremely important to users of paint ball markers which are intended for such recreational war games, as well as those used for other purposes, is the rate at which the marker may be fired. Obviously, markers which are capable of increased firing rates offer the user a significant competitive advantage over his/her fellow combatants. One significant factor which influences the firing rate of any weapon is the type of hammer and bolt assembly. Paint ball markers typically may employ manual, semi-automatic and fully automatic firing arrangements. As is well known, manual firing arrangement requires appropriate manipulation of the trigger before successive projectiles are fired. In contrast, a semi-automatic firing arrangement enables a projectile to fired and reset each time the trigger is depressed, while an automatic firing arrangement will fire multiple projectiles each time the trigger is pulled and held. 
   In paint ball markers that are semi-automatic, a new projectile is automatically loaded into firing position immediately after launch of a preceding paint ball. Such paint ball markers typically utilize a reciprocating bolt. The bolt serves two primary functions. First, the bolt cycles between a loading position in which the outlet of the projectile magazine is uncovered permitting a paint ball to drop into a breech, or bolt chamber, of the paint ball marker, and then to a launch position in which the bolt moves toward the muzzle or barrel of the marker covering the magazine outlet. Second, when in the “launch” position, the bolt re-directs a charge of compressed gas released from a chamber in the marker to propel the paint ball out the muzzle end of the barrel toward a target. The expanding gas of the propellant charge transfers energy to the projectile, expelling it from the barrel of the marker. It is the efficiency of this energy transfer that ultimately determines what quantity, i.e., pressure of propellant charge required to propel a paint ball at a given velocity. 
   For an automatic or semiautomatic marker using this independent bolt to hammer configuration, a three-way valve is used to direct compressed gas through a ram to reset the marker to be ready for the next firing. The operational speed of the three way valve and the ram directly affect the operational speed of the paintball marker. Continuing in the operational sequence, the trigger is further pulled past release of a sear so that a timing rod acts through a mechanical assembly to direct gas through the three-way valve to the ram that pushes the hammer and bolt rearward to the reset position. During the rearward movement, the hammer compresses a spring until the hammer is retained by engagement of a trigger sear in preparation for a next firing. The timing rod is adjustably connected to a coupler at the three-way valve to achieve correct timing. The effective length of the timing rod is precise to assure that gas is released at only the appropriate time to reset the marker. If the timing rod is set improperly, the reset occurs at the wrong time relative to the firing sequence, or not at all, and the marker fails to operate. 
   Variances in friction between the hammer and its chamber wall, whether caused by wear, dirt or the like, affect the magnitude and duration of hammer pressurization required to fully reset it. If friction is low, the hammer moves quickly and smoothly and the relevant volume of gas in the hammer chamber expands rapidly. Such rapid expansion may detract from the pressure used to discharge the projectile and projectile velocity is reduced. On the other hand, if friction is higher, the hammer may move more slowly, the volume of gas in the hammer chamber expands slowly and the primary valve is retained open for a longer period of time. As a consequence, substantially full input pressure continues to be applied to the projectile, notwithstanding that it is well down the barrel. This decreases the consistency and predictability of projectile velocity and thus effects the “dynamics” of projectile discharge such that projectile velocity may not be the same from shot to shot. As a result, the marker may require a different aiming point for each shot—this is a very annoying problem for the user. 
   To understand this invention, operation of paintball markers in general must be understood.  FIG. 1  is presented to depict a paint ball maker  100  of the prior art. This prior art marker needs to be understood to aid in the description of the improved ram assembly as set forth in this invention. 
   As shown in  FIG. 1 , the basic marker  100  comprises a marker body  110  with an attached barrel  112 , trigger assembly  114 , and reset ram assembly  116 . The reset ram assembly  116  includes a three-way valve  117  which is controlled by the trigger  153 . A compressed gas supply, not shown, is connected to receiver  118  and regulator  119 . The receiver  119  directs compressed gas through first line  115  to the reset ram assembly  116  from the three-way valve  117  attached to the marker body  110 . A second line  113  is connected from the front of the valve  117  to the rear of the reset ram assembly  116 . With these connections, the three-way valve  117  controls the position of the valve ram  152  within the reset ram assembly  116 . The reset ram assembly  116  is connected by the valve ram  152  to the back block  142 . The back block  142  is connected to the bolt  140  and has a limited sliding connection with the hammer reset rod  146 . In this manner, the trigger controls the reset ram assembly  116  and the reset ram assembly  116  directly controls the position of the bolt  140  and influences the position of the hammer  128  through the valve ram  152 . 
   The bolt  140  controls the loading of the paintball projectile  122  into the firing chamber  124 . A paint ball projectile magazine  120  is mounted to the marker body  110  to supply paint ball projectiles  122 . When the bolt  140  is in the rearward bolt loading position the paintball falls into the bolt chamber  124 . The bolt  140  is then moved into the firing position as shown in  FIG. 1 . 
   The bolt  140  includes forward passage  141  which is sealed from passage  132  in the rearward or reset position. The bolt  140  may include appropriate o-ring seals, not numbered, to effectively create a piston effect to the bolt  140  as it reciprocates in the bolt chamber  124 . When the bolt  140  is then moved into the firing position, the bottom opening of the forward passage  141  will be in alignment with passage  132  thereby directing compressed gas into chamber  124  to expel the paint ball  122 . Now that bolt  140  movement is understood for chambering a paintball projectile  122 , the release of the pressurized gas and reset of the marker will be understood through the motion of the hammer  128 . 
   Parallel to the bolt chamber  124  is a hammer chamber  126  in which the prior art version of a hammer  128  is shown in the reset position  129  from which the hammer  128  reciprocates. A propellant storage chamber  130  receives compressed gas from the receiver  118  and regulator  119  via conduits, not shown, to supply compressed gas for propelling the paintball  122 . The compressed gas in the storage chamber  130  is held back by the poppet valve  136  which is opened by movement of the exhaust valve pin  134 . Once the valve  136  is opened, compressed gas travels through firing gas supply passage  132  and the bolt passage  141  into the bolt chamber  124  for discharging the paintball projectile  122 . The firing valve  136  is normally held closed by firing valve spring  138 . 
   Just as the back block  142  affects the position of the bolt  140  in the bolt chamber  124 , the back block influences the position of the hammer  128  via the sliding connection of the reset rod  146  with the back block  142 . In this prior art version  100  the reset rod  146  is fixably attached to the hammer  128  and has a sliding connection with the back block  142 . When the hammer  128  is released, the pressure of spring  145  moves the hammer  128  forward and the reset rod  146  slides in the back block  142 . An artificial limit may be imposed on the forward movement of the hammer  128  by limiting the movement with the flange  144  of the reset rod  146  striking the back block  142 . 
   During the reset phase, the back block  142  normally returns the bolt  140  and contacts the flange  144  on the reset rod  146  to return the attached hammer  128  to the reset position shown in  FIG. 1  by compressing spring  145  to the position as shown. The back block  142  and bolt  140  will then return to the firing position. This leaves the reset rod  146  extended. 
   When the three way valve  117  is in a first position, compressed gas is directed through the first ram connection  115  to the front side  101  of the internal piston  102  of the ram  116 . This causes the internal piston of the ram  116  to move rearward and creates a pressure on the back side  103  of the internal piston  102 . This back pressure causes compressed gas to form which travels back to the three way valve  117  through the second ram connection  113  to be exhausted through the exhaust port  104  in the three way valve  117 . A similar situation occurs for the second side  103  of the ram  116 , creating an exhaust gas passing out of the exhaust port  105  on the first side of the valve  117 . This creation of additional pressures on the opposite side of the ram  116  from the incoming gas causes a resistance which is made even greater by the resistance of reversing the gas flow through the supply lines  113 ,  115  and the three way valve  117 . This resistance causes a reduction in the speed at which the ram  116  may operate for the given pressures that are used in the marker  100 . Thus, an improved design is needed to overcome this problem. 
   Thus, it may be seen that the prior art is very limited in their teaching and utilization, and an improved paintball marker is needed to overcome these limitations. 
   SUMMARY OF THE INVENTION 
   The present invention is directed to an improved paintball marker utilizing compressed gas. The paintball marker features an improved trigger assembly with an air assist trigger mechanism and a gas operated ram apparatus for use with compressed gas. Of note is the construction of the ram apparatus within the trigger assembly. 
   The ram is placed below the sear assembly and adapted to motivate the sear to engage the hammer. The ram includes a housing defining a central aperture encasing an internal piston coupled to an external connection. Within the central aperture, the internal piston defines a first side chamber and a second side chamber. The internal piston is movably sealed within the central aperture such that introduction of the compressed gas to the first side chamber creates movement in a first direction that results in second end compression resistance. This resistance biases the ram member further biasing the sear mechanism to engage the hammer. The remaining resistance is exhausted through a second end exhaust. 
   Objects and advantages of the present invention include direct venting of exhaust gases, reduced ram resistance, increased ram operating speed, increased operating speed for the paintball marker, and the elimination of return airflow resistance. These and other objects and advantages of the present invention, along with features of novelty appurtenant thereto, will appear or become apparent by reviewing the following detailed description of the invention. 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     In the following drawings, which form a part of the specification and which are to be construed in conjunction therewith, like reference numerals have been employed throughout wherever possible to indicate like parts in the various views: 
       FIG. 1  displays a schematic view of the prior art paintball marker. 
       FIG. 2  displays a schematic view of the left side of the new trigger assembly. 
       FIG. 3  displays an exploded view of the trigger assembly. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 2  is a schematic drawing of the trigger assembly  100  showing the air assist trigger assembly  200 , the ram assembly  300 , the secondary regulator  400 , and the sear assembly  500 .  FIG. 3  is an exploded view of the trigger assembly  100  showing the placement of the air assist trigger  200 , the ram assembly  300 , the secondary regulator  400  and the sear assembly  500  within the trigger frame  110 . 
   During operation of the paintball marker, the pressurized gas system (not shown) releases high pressure gas to the primary regulator (not shown) and low pressure gas to the secondary regulator  400 . The high pressure gas, approximately 450 psi, is utilized to fire the paintball from the breech. The low pressure gas, approximately 90 to 120 psi, is utilized by the air assist trigger assembly  200  and the ram assembly  300 . 
   The air assist trigger assembly  200  is located above the trigger  112 . In an alternative embodiment, shown in  FIGS. 2 and 3 , the trigger  112  is connected to the air assist assembly  200 . The air assist assembly  200  features a mechanical three-way valve  201 . As shown in  FIGS. 2 and 3 , the three-way valve  201  is a modified electronic Humphreys valve (HEB10A3-GL-D7). For the present invention, the three-way valve  201  has been stripped of its electronic elements to function as a mechanical valve. The three-way valve assembly  201  is closed in its resting state. Upon movement of the trigger  112 , the valve assembly  201  is motivated to open to allow the flow of low pressure gas to flow within the valve  201  through the valve intake port  206 . The trigger  112  features a motivating member  114  protruding from the trigger arm  113 . When the trigger  112  is pressed backward to fire a paintball, the motivating member  114  is pushed upward to bias a spring button  202  of the air assist assembly  200 . The spring button  202  is pushed upward into the air assist assembly  200  to open the three-way valve  203 . The internal piston  222  of the three-way valve  201  moves in an extending direction. Upon forward movement of the trigger  112 , the spring button  202  is released downward, thus closing the three-way valve  203 . The low pressure gas is then released through an exhaust system  213 , releasing low pressure gas to motivate the ram assembly. The internal piston  222  is then allowed to return to its resting position. 
   The ram assembly  300  is located below the sear assembly  500  within the trigger frame  110 . The ram assembly  300  features a housing  301  with a central aperture  302 , an internal piston  303 , a first side chamber  304 , a second side chamber  306 , a first side valve  310 , and a sear engaging assembly  305 . Upon exhaust from the air assist assembly  200 , the ram assembly  300  receives low pressure gas via a first gas input  311  of the first side valve  310 . 
   The housing  301  of the ram assembly  300  form a central aperture  302  with an internal piston  303  dividing the central aperture  302  into a first side chamber  304  and a second side chamber  306 . The internal piston  303  is sealed to the wall of the internal aperture  302  by a piston seal  324 . 
   The introduction of the compressed gas to the first gas input  311  of the first side valve  310  results in movement of the internal piston  303  towards the second end of the ram assembly  300  which we call a second direction movement  342 . Because the piston  303  is sealed to the wall of the housing  301 , this results in the initial formation of a slight second side chamber compression resistance  344 . The second side chamber  306  houses the sear engaging assembly  305 , and upon the presence of second side chamber compression  344 , the sear lever  307  of the sear engaging assembly  305  biased. The sear lever  307 , as shown in  FIG. 2 , is an S-shaped lever with a first leg  308  and a second leg  309 . Upon compression within the second side chamber  306 , the first leg  308  is motivated forward toward the front of the second side chamber  306  and the front of the trigger assembly. This forward movement of the first leg  308  motivates the second leg  309  downward biasing a spring  316  of the sear engaging assembly  305 . With the second leg  309  biased downward, the lower leg  503  of the sear  501  is allowed to move rearward to rest above the second leg  309  of the sear lever  307 . This rearward movement, in turn, motivates the upper leg  504  of the sear  501  upward, engaging the hammer of the paintball marker. The second side chamber exhaust  346  is adapted to release the remaining resistance  344 . Upon return movement of the sear  501  directly after firing of the paintball marker, the sear lever  307  is returned to its original upward position by means of the spring  316 . 
   From the foregoing, it will be seen that this invention well adapted to obtain all the ends and objects herein set forth, together with other advantages which are inherent to the structure. It will also be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims. Many possible embodiments may be made of the invention without departing from the scope thereof. Therefore, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.