CROSS-REFERENCE TO RELATED APPLICATION(S)The present application derives priority from U.S. provisional application Ser. No. 61/467,098 filed 24 Mar. 2011.
BACKGROUND OF THE INVENTION(1) Field of the Invention
The present invention relates to paintball guns and, more particularly, to a paintball marker with a more efficient and reliable pneumatic bolt firing mechanism.
(2) Description of the Background
Paintball has become an extremely popular hobby and, for some, a profession. The guns used to fire the paintballs are referred to as “markers”. Paintball markers are pneumatic projectile launchers that fire encapsulated paintballs by releasing a burst of gas (typically CO2or compressed air)
Current paintball markers are very sophisticated devices comprising a reservoir of compressed gas connected to a regulator, and a trigger mechanism for actuating the regulator to discharge the gas, ejecting paintballs from the chamber through a barrel at between 280 and 300 feet per second. The barrel has a closed breech end leading to an open muzzle. A magazine of paintballs is typically mounted above the breech of the paintball marker, and the paintballs are fed into the firing position automatically. Such paintball markers typically utilize a reciprocating bolt that moves between a loading position that permits a paintball to drop into the breech, and a firing position in which the bolt moves toward the muzzle of the marker, covering the magazine outlet. Once in the firing position the bolt re-directs a charge of: compressed gas that propels the paintball out the muzzle.
There are a number of design factors that go into a well-designed firing mechanism. Efficiency is important since the capacity of the gas cylinders is limited. Thus, it is desirable to maximize the number of shots possible from a single cylinder. This in turn requires conservation of the gas used for each shot, plus efficient energy transfer from the released gas to the paintball projectile.
Conventional markers reduce the high pressure from the cylinder into a low-pressure charge for operating the bolt. Thus, the high pressure gas from the regulator is branched, one branch being reduced through a low pressure regulator (LPR). The low pressure conduit is used for operating the bolt, while the high pressure conduit ejects the paintball. Typically, the trigger is electronic and sends signals to one or more solenoids which in turn control application of the low pressure and/or high pressure to the bolt. A first signal to the solenoid(s) delivers the low pressure charge to the bolt for moving it from loading to firing position, and a second delivers a high pressure charge to the bolt, electing paintballs from the chamber through a barrel at between 280 and 300 feet per second.
The bolt typically comprises a hollow tubular member resident in the chamber of the gun body and slidable along a stationary valve piston. The bolt is the only moving component within the chamber, and slides between loading and firing position upon application of the low pressure (90-250 psi) charge. In conventional markers this low pressure charge is fed from the compressed gas cylinder through a low pressure regulator (LPR) proximate the cylinder, and from there to the rear of the bolt. This prolonged flow path is inefficient. Moreover, the high-pressure (300 psi) propellant charge enters the bolt generally perpendicular to its axis through a port or opening in the side of the bolt. This abrupt right-angle junction creates turbulence in the flow stream and deprives it of efficiency.
There have been efforts to improve the bolt configuration. For example, U.S. Pat. No. 6,474,326 discloses a bolt with flared angular ports that eliminate the “corner” formed at the intersection of the prior art perpendicular flow passages. The flared ports reduce turbulence in the propellant charge and minimize energy loss.
Other examples of paintball marker guns used in the field include Anderson, U.S. Pat. No. 5,515,838 (paintball gun with a passage for porting pressurized gas to a ball projectile); Lukas et al., U.S. Pat. No. 5,613,483 (a gas powered gun with a piston and cylinder assembly for ejecting projectiles from the gun) and Lotuaco, III, U.S. Pat. No. 6,065,460 (gas-powered paintball gun with two pressure regulators; one for supplying lower pressure for loading paintballs and one for high pressure for expelling the paintball from the barrel.)
There remains a need for an integrated bolt engine for a paintball gun that integrates the low pressure regulator (LPR) directly into the bolt, eliminating the inefficient low pressure flow path, conserving parts and improving reliability.
SUMMARY OF THE INVENTIONIt is, therefore, a primary object of the present invention to provide a high-efficiency paintball marker with pneumatic firing mechanism comprising an integrated bolt engine including a hollow reciprocating bolt resident in the chamber of the gun body and slidable therein, a stationary valve piston inserted within the bolt for sealing said chamber, and a low pressure regulator (LPR) for reciprocating the bolt integrated directly into the bolt engine, and particularly into the valve piston.
It is another object to provide a marker capable of emptying a hopper full of paintballs with a standard (68 cubic inch) air tank and a standard (e.g., 4000 psi) fill to the tank, by minimizing both high and low pressure flow paths between cylinder and bolt as described above.
It is another object to admit both the high-pressure (300-400 psi) propellant charge and low pressure (90-250 psi) bolt-action charge radially in through multiple ports or openings in the side of the bolt to avoid perpendicular flow paths.
In accordance with the foregoing objects, a high-efficiency paintball marker is provided with a pneumatic firing mechanism comprising an integrated bolt engine with a hollow bolt and a stationary valve piston inserted within the bolt. A low pressure regulator (LPR) is integrated directly into the stationery valve piston for reducing the high pressure charge in order to move the bolt rapidly forwardly from a loading position towards its front shooting position, at which point the trigger causes high pressure gas to be released into the barrel through a high pressure gas passageway running through the center of the bolt.
The improved bolt engine employs fewer parts, is much simpler to manufacture, less prone to wear, and more reliable in operation. The net result is a high-efficiency tournament grade paintball marker that makes more efficient use of compressed gas, thereby allowing firing of more rounds per charge, and which is nevertheless simple in construction and easier to manufacture.
BRIEF DESCRIPTION OF THE DRAWINGSOther objects, features, and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments and certain modifications thereof when taken together with the accompanying drawings in which:
FIG. 1 is a perspective view of the paintball marker2 incorporating an integrated bolt engine according to the present invention.
FIG. 2 is a side view of the integrated bolt engine removed from main body10 (with the chamber in which it is inserted shown above in dotted lines).
FIG. 3 is a side cross-section of thevalve piston30 inclusive of the low pressure regulator (LPR) at left, andFIG. 4 is a perspective view.
FIG. 5 is a composite photo of the individual components of thebolt20FIG. 2.
FIG. 6 is a composite photo of the individual components of the LPR ofFIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)The present invention is an improved paintball marker with a high-efficiency and reliable pneumatic bolt firing mechanism. The paintball marker uses a high-pressure pneumatic charge from a conventional air tank. (3000-4000 psi) and a conventional high-pressure regulator (HPR) set to regulate to 300-400 psi for firing the paintball. A pneumatic bolt engine resident in the chamber reciprocates from a loading position in which a paintball is admitted from an external hopper into the chamber and a firing position. Reciprocation of the pneumatic bolt engine is driven by a low-pressure charge (90-120 psi). To get this from the HPR, the pneumatic bolt engine employs an integral low pressure regulator which internally regulates the higher-pressure (300-400 psi) charge into a low-pressure charge (90-120 psi) for self-actuation and loading. Once a paintball is loaded, manual or electronic trigger-actuation admits the high-pressure (300-400 psi) pneumatic charge into the bolt to expel the paintball.
The improved pneumatic bolt engine generally comprises a stationary valve piston affixed in the chamber, and a tubular bolt slidably mounted on the valve piston and movable for reciprocation within the chamber. In accordance with the present invention the low pressure regulator (LPR) is integrated directly into the valve piston, helping to minimize air flow paths. The tubular bolt is the only moving component within the chamber, and reciprocates between rear loading and forward firing positions upon application of the low pressure charge from the integral LPR. Once in the firing position the high pressure (300-400 psi) charge to the bolt ejects the paintball from the chamber through a barrel at between 280 and 300 feet per second. The valve piston does not move, but both charges are fed radially in through multiple ports opening in the side of the valve piston. This radial-flow design simplifieschamber13 manufacturing and makes more efficient use of: compressed gas, thereby allowing firing of more rounds per charge.
FIG. 1 is a perspective view of a paintball marker2 according to an embodiment of the present invention. The paintball marker2 includes amain body10 with a pistol-handle grip54 and pivotingtrigger56 attached to thehandle grip54. Themain body10 includes a cylindricalinterior chamber13 screw-threaded at the leading end for attachment of atubular muzzle92. Abarrel assembly94 is attached to themuzzle92, and paint balls are discharged from internal to thechamber13 through themuzzle92 andbarrel assembly94. A conventional compressedgas cylinder55 is attached to the bottom of thehandle grip54 through aregulated gas inlet52, in a known manner, for introduction of compressed gas fromcylinder55 into thechamber13 ofmain body10. Thecompressed gas cylinder55 is a conventional gas cylinder or storage tank coupled to thegas inlet52 as a source of pressurized gas (air or CO2). Theregulated gas inlet52 incorporates any of a variety of commercial regulator assemblies suitable for decreasing the pressure of air fromcompressed gas cylinder55 from between 3000-4000 psi to between 300-400 psi (firing pressure).Regulated gas inlet52 feeds the gas intohandle54 for powering the paint ball marker. A suitable regulatedgas inlet52 may comprise a conventional ASA (Air Source Adapter) Regulator with safety-vented air source connector, preferably using standardized bottle threading. The SEM Company produces a line of suitable ASA adapters. The preferred gas inlet regulator should be adjustable to provide an approximate 300-400 PSI output. Regulator adjustment may be accomplished by turning a setscrew located on the bottom of the regulator, and a variety of commercially-available paintball regulators are well-suited for these specifications (such as the Bulldog™ 0-900 psi adjustable regulator).
Internally, the compressed gas is fed through thebody10 as will be described to the integrated bolt engine of the present invention, which is seated in thechamber13. The integrated bolt engine in combination with the trigger serves as a firing mechanism to both load and expel the paintballs. The integrated bolt engine incorporates its own integral LPR (as will be described) to provide the low pressure gas charge (approx. 90-250 psi) for reciprocating the bolt between its loading and firing positions. When in the loading position, a paintball is fed fromhopper65 into thechamber13 through aport12.Hopper65 may be any conventional paintball feeder or hopper. With a paintball loaded the bolt is moved to the firing position, and the integrated bolt engine (under trigger control supplies the high pressure (300-400 psi) charge to expel the paintball throughmuzzle92 andbarrel assembly94.
The integrated bolt engine enclosed inchamber13 extends coaxially withbarrel90 and is offset from the compressedgas cylinder55 attached to the distal end of thehandle54. In the illustrated embodiment thecompressed gas cylinder55 runs parallel to thebarrel90, though alternatively it may extend downwardly. The regulated high pressure airflow supplying both the high-pressure gas charge and low-pressure gas charge passes directly upward through a conduit in thehandle54 and is selectively ported radially to the integrated bolt engine.
Thetrigger56 is pivotally attached to thehandle grip54 behind a conventional trigger guard, and a forward stabilizing handle57 protrudes downward in advance of the trigger guard.
The pivotingtrigger56 may activate a manual valve or a programmable electronic controller circuit. Preferably, a commercially-available electronic controller circuit is used. Such circuits may be pre-programmed to output one or a sequence of firing control signals that range from single-shot (semi-automatic) mode, to fully-automatic burst modes for firing a user-selectable number of paintballs machine-gun style.
FIG. 2 is a side view of the integrated bolt engine removed frommain body10 with thechamber13 in which it is inserted shown above in dotted lines. Thechamber13 is a cylindrical bore with a screw-threaded exit at the rear of thebody10. Afluid passage60 approaches thechamber13 perpendicularly from the bottom of thehandle54 and flares out beneath thechamber13, entering the chamber at two spacedports61,63. Anelectronic solenoid valve64 resides in thefluid passage60 betweenports61,63 for selectively permitting flow toport63. Where a manual trigger is employed,electronic solenoid valve64 may be replaced with a mechanical valve. Theelectronic solenoid valve64 is electrically connected to the electronic controller and is thereby controlled by the control signals in accordance with thetrigger56 action.
The bolt engine includes astationary valve piston30 affixed in thechamber13, atubular bolt20 slidably mounted on thevalve piston30 and movable within thechamber13, and a low pressure regulator (LPR)66 integrated directly into thevalve piston30. Thebolt20 is the only moving component, sliding between rear loading position (shown) and forward firing position undersolenoid valve64 control.
Solenoid64 selectively switches open closed to admit a charge of high pressure compressed gas throughport63 directly through thebolt20 and into the chamber to fire a paintball. The same high pressure compressed gas is always applied throughport61 to the back of thevalve piston30, but this flow path is regulated (as described below) down to a low-pressure charge of approx. 90-250 psi. If high pressure compressed gas is applied throughport63 it overcomes the low pressure charge and the bolt remains stationery. However, after the high pressure charge fromport63 is dispersed, the low-pressure charge actuates the internal bolt engine, thereby movingbolt20 from the loading position shown (in which a paintball is gravity fed into the chamber in advance of the bolt engine) to a ready-to-fire position in which the paintball is moved into the breech ofchamber13, immediately and automatically followed by another high-pressure gas charge released through thebolt20 and into thebarrel assembly90 of the gun. Thus, the high-pressure charge counterbalances the low pressure charge. Each pull of thetrigger56 expels the paintball and switches off thesolenoid64 and the high-pressure gas feed. The high-pressure charge dissipates leaving the low-pressure charge to move thebolt20 back to its loading position (shown) in which another paintball is gravity fed into thechamber13. As soon as thebolt20 regains its home position the control signal causes thesolenoid64 to selectively admit high pressure compressed gas to the internal bolt engine, re-pressurizing the bolt engine.
Pulling thetrigger56 immediately switches off the high-pressure as feed, allowing the low pressure gas feed to thereby movebolt20 from the loading position shown to the ready-to-fire position in which the paintball is moved into the breech, and followed by release of the accumulated high-pressure gas charge through the bolt and into thebarrel assembly90 of the gun.
To accomplish the foregoing in accordance with the present invention, the bolt engine includes a low pressure regulator (LPR)66 integrated directly into thevalve piston30. Thefluid passage60 enters the chamber at two spacedports61,63, and each port preferably comprises a radial array of four porting holes equally angularly spaced to provide vents intochamber13.Port61 provides the gas supply to theLPR66, whileport63 selectively provides the high pressure gas supply. TheLPR66 provides a source of low-pressure compressed gas (approx. 90-250 psi) for moving thebolt20 within thechamber13, from the loading to ready-to-fire positions in accordance with the firing cycle described above.
Thestationery valve piston30 is threaded into thechamber13 of the marker body by screw-threads32 and resides substantially within thechamber13. A threaded distal neck protrudes, and acap40 is secured by screw-threads33 to the threaded distal neck. Thecap40 is part of theLPR66 and allows adjustment of the pressure of the low-pressure compressed gas.
When theslidable bolt20 resides against the rear of thechamber13 as shown, it seals against anannular collar31. In this configuration the firing mechanism is considered a “closed bolt” which allows a paintball to drop into thechamber13 just in advance of thebolt20. The high pressure charge remains applied throughfluid passage60 to bothports61,63 when theslidable bolt20 is closed and thetrigger56 is not pulled, thereby pressurizing thebolt20.
When thetrigger56 is pulled it switchessolenoid64 off, which cuts off the high pressure charge throughport63 and effectively switches to the low pressure charge (90-750 psi) of compressed gas fromLPR66 up through an annular array oflow pressure ports38, which vent to thechamber13 throughports36. Thus, upon squeezingtrigger56, this low-pressure charge drives thebolt20 forward, feeding the ball into the breech ofchamber13. Immediately upon reaching its full extension to the ready-to-fire position, the high pressure charge (300-400 psi) of: compressed gas is expelled through an annular array ofdistal lets81 at the end ofbolt20. The paintball fires. The entire process repeats itself when thetrigger56 is depressed again manually or automatically if the controller circuit is set to a burst firing mode. A key improvement in the foregoing is the integration of theLPR66 into thevalve piston30 leaving just a single moving component (bolt20) that slides withinchamber13.
The structural configuration necessary for operation of thebolt20 andvalve piston30 will now be described. Theslidable bolt20 andvalve piston30 are fitted together end to end to form a contiguous in-line assembly, thevalve piston30 remaining stationery and stoppering the rear ofchamber13.
FIG. 3 is a side cross-section of thevalve piston30, inclusive ofLPR66, andFIG. 4 is a perspective view of just thevalve piston30.
Thevalve piston30 includes acentral passage34 in communication withfront ports36,38 and39. Thepassage34 ends but thepiston30 continues along areduced diameter neck35 to aplug37. Theplug37 is encircled by an O-ring43 and forms a seal that seats against and sealschamber13. When seated, theplug34 prevents the release of high-pressure compressed gas from thechamber13. The pressure of the compressed gas on theplug34 keeps thevalve piston30 in a closed position, with theplug34 securely seated. Three additional O-ring seals43 are disposed along the rear length ofvalve piston30 to seal against the interior of thechamber13. These include O-ring seals43 on opposing sides offront port39 that seal off compressed gas and force it intofront port39 ofvalve piston30 and intocentral passage34, thereby allowing it to escape throughport36 into thebolt20. The surface of thepiston30 around theport36 is slightly concave about anannular trough47 to allow free flow of the escaping air. TheLPR66 is inserted into the open rearward end ofvalve piston30 and is contained therein byadjustable cap40. TheLPR66 provides a source of low-pressure the compressed gas(approx. 90-250 psi) for moving thebolt20 within thechamber13, from the ready-to-fire position through the firing cycle described above. TheLPR66 is essentially a spring-loaded variable-pressure valve assembly for which cap40 provides the adjustable-pressure bias to set the valve pressure, as described below.
FIG. 5 is a composite photo of the individual components of thebolt20 ofFIG. 2. Thebolt20 is preferably of two piece tubular construction, comprising a vented forward portion (FIG. 5B) screw-threaded into a maincylindrical body24 as seen inFIG. 5A, threaded to ajet nozzle tip22 as seen inFIG. 5B. Thejet nozzle tip22 screws into themain body24 directinglet nozzles81 forward toward the breech/paintball. The main cylindrical body4 is defined by two annular channels containing O-rings43 as shown, for sealing against the walls ofchamber13.
FIG. 6 is a composite photo of the individual components of theLPR66 spring-loaded variable-pressure valve assembly ofFIG. 2 which is inserted into thevalve piston30. TheLPR66 includes a Shrader-type spring-loadedvalve core78 inserted and affixed in position inside thestationery valve piston30 within its internal cavity. Increasing bias on the distally-protruding stem ofvalve core78 increasingly opens it. Apiston72 embraces the distally-protruding stem ofvalve78 and is depressable there against to openvalve78.Piston72 is likewise defined as an annular member having an internal cavity and external flange defined by a channel for seating an O-ring75. Thepiston72 is spring pre-biased into the stem ofvalve78 by aspring73 mounted behind theadjustment cap40, and bearing there against on awasher76. Tightening thecap40 compresses thespring73 andpiston72 against thevalve78 and decreases the valve opening pressure (and vice versa), thereby adjusting the low pressure supply to bolt20 to within a range of from 90-220 psi.
The foregoing configuration is simple and easy to manufacture, and yet highly efficient. Whereas conventional paintball markers may yield 300-400 shots per canister of compressed gas, the foregoing configuration has been shown to yield 1300-1400 shots. This is a critical statistic in tournament play where it is desirable to minimize the need for carrying and changing air canisters.
Having now fully set forth the preferred embodiment and certain modifications of the concept underlying the present invention, various other embodiments as well as certain variations and modifications of the embodiments herein shown and described will obviously occur to those skilled in the art upon becoming familiar with said underlying concept. It is to be understood, therefore, that the invention may be practiced otherwise than as specifically set forth in the appended claims.