PAINTBALL MARKER PNEUMATIC FIRING ASSEMBLY AND

METHOD

Field of the invention

The present invention relates to a pneumatic firing assembly for a paintball marker. However, it will be appreciated by those skilled in the art that the invention is not limited to this particular field, and can be applied to any application where the delivery of a fixed volume of fluid is required.

Background of the Invention

The sport of paintball involves competitors using compressed gas powered guns, known as markers, to fire gelatin capsules at other competitors. The marker harnesses the power of a compressed gas, such as carbon dioxide or compressed air, to launch the capsules. The capsules typically contain polyethylene glycol, water based liquids and dyes. When a competitor is hit by such a capsule, the capsule is intended to rupture so that the dye marks the person's clothes or equipment, indicating a hit and the elimination of that competitor from the game.

Existing paint ball markers fall into two general categories: stacked tube systems; and inline systems.

Stacked tube systems utilise two or more tubes which house reciprocating valves and other components. Linking pins are generally used to achieve interaction between the respective parts. Stacked tube systems advantageously permit high speed capsule firing, because the components included in the firing assembly are generally independent of each other, thereby minimising friction within the marker. However, a problem with stacked tube systems is that the multiple tube housings increase the overall size and hence portability of the assembled stacked tube marker. In contrast, inline systems use a single main bore for all pneumatic components.

However, whilst the size of the assembled inline marker is generally smaller, the maximum capsule firing speeds are generally lower than stacked systems as a result of the connectivity of the firing parts, the increased friction within the system and the pneumatic balancing which is required.

The pneumatic firing assembly, in particular the valves of a paintball marker effect the marker's operating characteristics such as the recoil of the marker after a capsule has been fired from the barrel, the amount of sound generated by the marker and the number of capsules that can be fired in a given interval of time.

Object of the Invention

It is the object of the present invention to overcome or at least ameliorate at least one of the above disadvantages, or at least to provide a useful alternative to existing paintball marker firing assemblies.

Summary of the Invention In a first aspect, the present invention provides a paintball marker firing assembly comprising: a longitudinally extending, hollow casing having a proximal end and a distal end, said casing having a first pneumatic port and a second pneumatic port; a hollow bolt mounted within said casing, said bolt being adapted =to longitudinally reciprocate between a loading position in which said bolt is closest to said proximal end, and a firing position in which said bolt is furthest from said proximal end, a firing chamber adjacent said proximal end, a dump valve located within said casing adjacent to said proximal end, said dump valve being adapted to longitudinally reciprocate between an open position closest to said proximal end, in which said dump valve is in fluid communication with said firing chamber, and a closed position furthest from said proximal end, said dump valve being biased towards said closed position; a longitudinally extending, hollow firing valve mounted within said bolt and said dump valve, said firing valve being in fluid communication with said firing chamber; and a reciprocation valve adapted to deliver a pneumatic charge to one of said first and second pneumatic ports, wherein, when said dump valve is in the open position, a first pneumatic charge applied to said dump valve passes therethrough and is directed to said firing chamber, a second pneumatic charge is applied to said first pneumatic port and urges said bolt to move toward said firing position and said dump valve to move toward said closed

position, when said bolt reaches said firing position it causes said firing valve to open, and release a volume of compressed fluid from the firing chamber to fire a paintball, and said reciprocation valve to switch said first pneumatic charge to said second pneumatic port to urge said bolt to move toward said loading position and abut said dump valve to urge said dump valve to return to said open position.

In a second aspect, the present invention provides a paintball marker firing assembly comprising: a longitudinally extending, hollow casing having a proximal end and a distal end, said casing having a first pneumatic port; a hollow bolt mounted within said casing, said bolt being adapted to longitudinally reciprocate between a loading position in which said bolt is closest to said proximal end, and a firing position in which said bolt is furthest from said proximal end, a firing chamber adjacent said proximal end, a dump valve located within said casing adjacent to said proximal end, said dump valve being adapted to longitudinally reciprocate between an open position closest to said proximal end, in which said dump valve is in fluid communication with said firing chamber, and a closed position furthest from said proximal end, said dump valve being biased towards said closed position; a longitudinally extending, hollow firing valve mounted within said bolt and said dump valve, said firing valve being in fluid communication with said firing chamber; and a reciprocation valve in fluid communication with said first pneumatic port, wherein, when said dump valve is in the open position, a first pneumatic charge applied to said dump valve passes therethrough and is directed to said firing chamber, biasing said bolt toward said firing position, and said reciprocation valve applies a second pneumatic charge to said first pneumatic port, such that a force urging the bolt to the loading position is greater than a force urging the bolt to the firing position, further wherein activation of said reciprocation valve terminates the second pneumatic charge applied to said first pneumatic port, permitting said bolt to move toward said firing position and said dump valve to move toward said closed position, when said bolt reaches said firing position it causes said firing valve to open, and release a volume of compressed fluid from the firing chamber to fire a paintball, and said

reciprocation valve to deliver a third pneumatic charge to said first pneumatic port to urge said bolt to move toward said loading position and abut said dump valve to urge said dump valve to return to said open position.

A reciprocation stroke of the bolt is preferably longer than a reciprocation stroke of said dump valve.

The dump valve is preferably annular.

The dump valve is preferably pneumatically biased toward the closed position.

The dump valve is preferably spring biased toward the closed position, The reciprocation valve is preferably a solenoid valve.

The firing valve preferably includes one or more apertures adapted to permit fluid to pass from the centre of the firing valve to an inner surface of the bolt.

A distal end of the firing valve preferably includes a seal which fluidly seals against the inner surface of the bolt when the bolt is in the loading position, The bolt preferably has a region of reduced wall thickness defining an increase in the cross-sectional area of a hollow within the bolt when viewed in a plane extending perpendicular to a longitudinal axis of the casing, the region of reduced wall thickness permits fluid to pass between the bolt and the seal when the bolt is in the firing position.

In a third aspect, the present invention provides a method of operating a firing assembly of a paintball marker, said marker including a longitudinally extending, hollow casing having a proximal end and a distal end, said casing having first and second pneumatic ports, said method including the steps of: applying a first pneumatic charge to a dump valve located within said casing adjacent to said proximal end; passing said first pneumatic charge through said dump valve and directing it to a firing chamber adjacent said proximal end, applying a second pneumatic charge to said first pneumatic port to urge said bolt to move from a loading position, in which said bolt is closest to said proximal end, toward a firing position, in which said bolt is furthest from said proximal end;

biasing said dump valve away from said proximal end so that it moves with said bolt from an open position, closest to said proximal end, to a closed position, furthest from said proximal end; opening a firing valve mounted within said bolt and within said dump valve, when said bolt reaches said firing position, to release a volume of compressed fluid for firing a paintball; applying a third pneumatic charge to said second pneumatic port with a reciprocation valve to urge said bolt to move toward said loading position; and returning said bolt to said loading position and abutting said bolt with said dump valve to urge said dump valve to return to said open position.

In a fourth aspect, the present invention provides a method of operating a firing assembly of a paintball marker, said marker including a longitudinally extending, hollow casing having a proximal end and a distal end, said casing having a first pneumatic port, said method including the steps of: applying a first pneumatic charge to a dump valve located within said casing adjacent to said proximal end; passing said first pneumatic charge through said dump valve and directing it to firing chamber adjacent said proximal end; applying a second pneumatic charge to said first pneumatic port to bias said bolt toward a loading position, in which said bolt is closest to said proximal end, such that a force urging the bolt to the loading position is greater than a force urging the bolt to a firing position furthest from the proximal end; activating a reciprocation valve to terminate the second pneumatic charge, moving said bolt toward the firing position; biasing said dump valve away from said proximal end so that it moves with said bolt from an open position, closest to said proximal end, to a closed position, furthest from said proximal end; opening a firing valve mounted within said bolt and within said dump valve, when said bolt reaches said firing position, to release a volume of compressed fluid for firing a paintball;

applying a third pneumatic charge to said first pneumatic port with the reciprocation valve to urge said bolt to move toward said loading position; and returning said bolt to said loading position and abutting said bolt with said dump valve to urge said dump valve to return to said open position. The step of biasing the dump valve to reciprocate with the bolt from an open position to a closed position preferably includes applying a pneumatic load to the dump valve.

The step of opening the firing valve preferably includes passing a fluid from a central region of the dump valve, to an inner surface of the bolt, the fluid subsequently passes through a passage defined by a region of reduced wall thickness of the bolt to a paintball chamber.

Brief Description of the Drawings Preferred embodiments of the present invention will be described by way of example only, with reference to the accompanying drawings in which:

Fig. 1 is a schematic cross sectional diagram of a paintball marker showing the firing assembly;

Fig. 2A is a sectional firing sequence diagram according to a first embodiment in a loading position;

Fig. 2B is a sectional firing sequence diagram of the first embodiment with the dump valve closed;

Fig. 2C is a sectional firing sequence diagram of the first embodiment showing the bolt partially extended; Fig. 2D is a sectional firing sequence diagram of the first embodiment showing the bolt fully extended to a firing position;

Fig. 2E is a sectional firing sequence diagram of the first embodiment showing the bolt returning to the loading position;

Fig. 3 is a sectional view of a firing system according to the first embodiment in a loading position; and

Fig. 4 is a sectional view of a firing system according to a second embodiment in a loading position.

Detailed Description of the Preferred Embodiments

Fig. 1 shows a first embodiment of a paintball marker firing assembly 20 installed within a paintball marker 22. The assembly 20 includes a longitudinally extending, hollow casing 24 which has a proximal end 26 and a distal end 28. The casing

24 is formed from a number of sub casings or kegs which are connected to each other to define the outer casing shell and the hollow internal space 29.

The casing 24 has a first pneumatic port 30 and a second pneumatic port 32, which each provide a fluid passage from the outside of the casing 24 to its hollow interior.

A hollow bolt 40 is mounted within the casing 24. The bolt 40 is adapted to longitudinally reciprocate between a loading position (as depicted in Fig. 2A) in which the bolt 40 is closest to the proximal end 26 of the casing 24, and a firing position (as depicted in Fig. 2D) in which the bolt 40 is furthest from the proximal end 26. The bolt 40 has a hollow central region 42. The bolt 40 has a region of reduced wall thickness 44 defining a local increase in the cross-sectional area of the internal bore of the bolt 24 when viewed in a plane extending perpendicular to a longitudinal axis X of the casing 24.

The firing assembly 20 includes an annular dump valve 50 located within the casing 24 adjacent to the proximal end 26. The dump valve 50 is adapted to longitudinally reciprocate between an open position closest to the proximal end 26 (as depicted in Fig.

2A), and a closed position furthest from the proximal end (as depicted in Fig. 2B). In the embodiment shown in the drawings, the dump valve 50 is pneumatically biased towards the closed position. In an alternative embodiment not shown in the drawings, a spring, magnet or another suitable biasing means is used to bias the dump valve 50 towards the closed position.

Two dump valve ports 52, 54 are formed in the casing 24. The dump valve ports

52, 54 are in fluid communication with each other when the dump valve 50 is in the open position, by virtue of channel 56 formed in the dump valve 50. In contrast, the dump valve ports 52, 54 are isolated relative to each other when the dump valve 50 is in the closed position. The dump valve port 54 which is closest to the proximal end 26 is in fluid

communication with a firing chamber 90, located adjacent to the proximal end of the bolt 40.

The dump valve 50 includes a shoulder 58 formed on a circumferential surface of the dump valve, between two regions of different radial wall thickness. The firing assembly 20 includes a longitudinally extending hollow firing valve

60 mounted within the bolt 40. The firing valve 60 is in the form of a hollow, longitudinally extending rod, and the firing valve 60 is longitudinally fixed relative to the casing 24. The firing valve is fixed by a circlip, a screw thread or another suitable engagement to prevent the firing valve 60 from moving in the longitudinal direction. The firing valve 60 includes one or more apertures 62 in the form of airflow slots

62 which are adapted to permit fluid to pass from the centre of the firing valve 60 to a cavity or space 64 located between an outer surface of the firing valve 60 and an inner surface of said bolt 40. A distal end of the firing valve 60 has a radially formed seal, in the form of a rubber O-ring 61, which fluidly seals against the inner surface of the bolt 40 when the bolt 40 is in the positions shown in Figs. 2A to 2C.

As shown in Fig. 1, a reciprocation valve defined by solenoid valve 70 is housed in the marker 22. The solenoid valve 70 is located adjacent to the first pneumatic port 30 and the second pneumatic port 32, and the solenoid valve 70 is adapted to selectively control the flow of fluid between the first and second ports 30, 32. The solenoid valve 70 is a spool consisting of 3 or more seals. The spool is permitted to slide in a valve body with cross drilled holes. The spool can be positioned to direct air to the first pneumatic port 30, whilst closing and exhausting the second pneumatic port 32. Sliding the spool to another position will permit the input to be directed to the second pneumatic port 32 whilst closing and exhausting the first pneumatic port 30. The solenoid valve 70 is a five way port, because it has 1 input, 2 outputs, and each output has one exhaust (5 ports total). The spool is moved either directly or indirectly, by an electro magnetic coil electrically operated by a pilot valve.

The marker 22 includes a paintball feed tube 80 for inputting paintballs 82. The marker 22 also has a grip frame 84 with a trigger. The marker 22 further includes a compressed gas supply 86 and a compressed gas regulator 88. The flow of compressed gas from the gas supply 86 is split into two separate flows.

The first flow is directed through the dump valve 50 to a cavity 90 located adjacent the proximal end of the housing 24. This cavity 90 provides the pneumatic charge used to fire the paintball. The second flow is directed into the solenoid valve 70. The second flow is adapted to enter the first pneumatic port 30 and the second pneumatic port 32, for reciprocating the bolt 40 between the loading position (Fig. 2A) and the firing position (Fig. 2D) and back to the leading position.

The operation of the firing assembly 20 and marker 20 will now be described. A paintball capsule 82 is initially supplied to the feed tube 80 from a storage hopper (not shown) mounted vertically above the feed tube 80. The paintball capsule 82 is fed under the effects of gravity into the feed tube 80.

The paintball sits in front of the firing assembly 20, adjacent to the distal end 28 of the housing 24. The firing assembly 20 is initially configured as shown in Fig. 2A. At the start of a firing cycle, the solenoid valve 70 initially applies a pneumatic charge to the second pneumatic port 32, which urges the bolt 40 to rest in the loading position. The dump valve 50 is open, so a pneumatic charge passes therethrough, and that charge enters the chamber 90, and is stored there for subsequently firing the paintball 82. The dump valve 50 is pneumatically biased away from the proximal end of the assembly 20.

The pneumatic charge urging the bolt 40 to the loading position (closest to the proximal end) is larger than the biasing urging the dump valve 50 away from the proximal end, such that the bolt 40 remains in equilibrium in the loading position, and the dump valve 50 remains open.

The charge applied to the dump valve inlet 52 is continuously applied to the inlet 52 at all stages of the firing cycle.

When a user pulls the trigger, the solenoid valve 70 switches the compressed gas charge from the second pneumatic port 32, to the first pneumatic port 30, and accordingly, the equilibrium is broken.

The compressed gas delivered through the first pneumatic port 30 applies a force to a cavity 43 formed between the casing 24 and the bolt 40. The force causes the bolt 40 to move along a stroke away from the proximal end 26 of the casing 24, to the position shown in Fig. 2B. As the dump valve 50 is biased away from the proximal end 26, the dump valve 50 also moves in the same direction as the bolt 40. In the position shown in

Fig. 2B, the dump valve 50 is fully displaced toward the distal end and comes into abutment with an annular wall 92 of the casing 24. The wall 92 prevents further displacement of the dump valve towards the distal end 28. The dump valve is now closed, such that any compressed gas applied to dump valve port 52 is not permitted to exit from dump valve port 54, and the charge of air contained within the chamber 90 is trapped.

The bolt 40 continues to move away from the proximal end 26 of the casing 24 as shown in Fig. 2C. During this stroke the end 45 of the bolt 40 closes the paintball feed tube 80.

When the bolt 40 reaches the end of its stroke to the firing position shown in Fig. 2D, the firing valve opens. Accordingly, compressed gas trapped within the cavity 90 is forced under pressure through the centre of the firing valve 60 from the proximal end 26 towards the distal end 28. The compressed gas passes through the apertures 62 into the cavity 64 located between the outer surface of the firing valve 60 and the inner surface of the bolt 40. .. The compressed gas then enters the region of reduced wall thickness of the bolt 40 and passes around the end of the firing valve 60. At this point, the paint ball 82 is blocking the fluid flow path, thereby preventing the compressed gas from exiting the barrel of the marker 22. Accordingly, the increase of pressure behind the paint ball 82 causes the paint ball 82 to be fired from the barrel at high velocity. After a given period of time, the solenoid valve 70 is electrically actuated to switches between the first pneumatic port 30 and the second pneumatic port 32. The compressed gas is then directed into the second pneumatic port 32 causing the bolt 40 to reciprocate along a return stroke towards the proximal end, as shown in Fig. 2E. As the bolt 40 nears the end of the return stroke, the proximal end of the bolt 40 abuts the shoulder 58 within the dump valve 50. The return force provided by the bolt 40 is larger than the biasing force urging the dump valve 50 towards the distal end 28. Accordingly, the dump valve 50 moves with the bolt 40 back to the start position shown in Fig. 2A, and the dump valve 50 is accordingly reopened. The reopening of the dump valve 50 permits the chamber 90 to be recharged for firing a subsequent paint ball 82. The reciprocation stroke of the bolt 40 is longer than the reciprocation stroke of the dump valve. As a result, the dump valve 50 advantageously is not required to travel

along the full stroke of the bolt 40. The reduced stroke of the dump valve 50 minimises the mass of the reciprocating parts, reducing the recoil and noise levels produced by the marker 20. The reduced reciprocation stroke of the dump valve 50 also enables the firing assembly to fire paintballs 82 at an increased rate. A second embodiment of the firing system 100 is shown in Fig. 3. The second embodiment will now be described, with like reference numerals being used to indicate similar features. In this embodiment, the output line 102 of the dump valve 50 is in fluid communication with the hollow, proximal end of the firing valve 60. Accordingly, when the dump valve 50 is open, the compressed gas may pass through the dump valve 50 and enter the trailing end 26 of the firing valve 60, for charging the chamber 90. The compressed gas is then permitted to travel towards the distal end of the assembly 100 and pass through the apertures 62 to the cavity between the outer surface of the firing valve 60 and the inner wall of the bolt 40. The bolt 40 has a radial step 104 which defines a change in wall thickness of the bolt, and the radial step acts as a pneumatic actuation surface. ₌

In the second embodiment 100, there is a single pneumatic port 120 in the casing 24, which is in fluid communication with the bolt.

The operation of the second embodiment 100 will now be described. At the start of a reciprocation cycle, the dump valve 50 is open, and the bolt 40 is in the loading position. Compressed gas is applied to the input of the dump valve 50. The compressed gas passes through the dump valve 50 into the dump valve output line 102, and into the firing chamber 90 adjacent to the proximal end of the hollow firing valve 60. The increased internal pressure within the firing valve 60 applies a pneumatic force upon the radial step 104 which biases the bolt 40 towards the firing position. The dump valve 50 is also pneumatically biased away from the proximal end.

A pneumatic force is also applied to the pneumatic port 120, to urge the bolt 40 to stay in the loading position. Accordingly, the force acting upon the radial step 104 is opposite in direction to the force acting upon the pneumatic port 120. The pneumatic force urging the bolt 40 toward the proximal end is greater than the pneumatic force urging away from the proximal end. Accordingly, the bolt 40 remains static in the loading position.

In this embodiment, the solenoid 70 is a 3 port type valve, having a spool, but with only two seals. The inlet flow applied to the solenoid valve 70 is applied to the pneumatic port 120.

In an alternative embodiment not shown in the drawings, the reciprocation valve 70 is biased to the loading position by a magnet or a spring.

When the user of the marker 22 pulls the trigger of the grip frame 84, the solenoid valve 70 ceases to apply, or switches the compressed gas away from the pneumatic port 120, such that the static equilibrium is broken.

The forces acting on the bolt 40 to move towards the firing position become greater that the force holding the bolt 40 at rest. Accordingly, the bolt 40 reciprocates toward the firing position in the manner described above with regard to the first embodiment, and the paintball 82 is fired as already described.

After a given period of time, the solenoid valve 70 subsequently reapplies a pneumatic force to the pneumatic port 120 to the return the bolt 40 to the loading position and the dump valve 50 to the open position at the start of the firing cycle.

Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms.