The present invention relates to toy guns. The invention more particularly, although not exclusively, relates to toy guns that exploit compressed gas such as air as a propellant for either a shot of liquid such as water, or a projectile such as a soft dart.
Briefly stated, a fluid switch for toy guns and toy guns exploiting the fluid switch are provided.
There is disclosed herein a fluid switch for a toy gun, comprising:
Preferably, the fluid switch further comprises a second seal thought which the shaft also extends through and seals against.
Preferably, the seals are O-rings.
Preferably, the inlet is transverse to the shaft and the outlet is parallel to the shaft.
Preferably, the inlet is parallel to the shaft and the outlet is transverse to the shaft.
Preferably, the recess is in the form of an annular groove surrounding the shaft.
There is further disclosed herein a toy gun comprising:
Preferably, the toy gun further comprises a priming pump to pressurise the fluid in the reservoir.
Preferably, the toy gun further comprises an exhaust port via which fluid can escape to atmosphere.
Preferably, the toy gun further comprises a nozzle valve to open the nozzle, the nozzle valve activated by the trigger.
Preferably, the toy gun further comprises an auxiliary charge store of variable volume for storing pressurised fluid until the nozzle valve is opened whereupon the volume contracts resiliently to expel the fluid via the nozzle.
Preferably, the auxiliary charge store comprises a bladder.
Preferably, the auxiliary charge store comprises a spring-loaded piston.
There is further disclosed herein a multi-shot toy gun comprising:
Preferably, the multi-shot toy gun further comprises a motor or wind-up gearbox acting upon or comprising at least part of said activation means to reciprocate the shaft so that the recess passes the seal repeatedly.
Preferred forms of the present invention will now be described by way of example with reference to the accompanying drawings, wherein:
In
A reservoir 11 is sealed by a cap via which water can be replenished. Extending upwardly into the reservoir 11 is a riser tube 18. The riser tube 18 extends almost to the top of the reservoir 11 so that its exit is above water level. The riser tube 18 is connected to a junction 17. A priming conduit 16 extends from the junction 17 to a primer 13. Primer 13 comprises a reciprocating handle 14 connected to a priming piston 15 which incorporates a one-way valve 43.
Also attached to the junction 17 is a fluid switch 20 activated by a trigger 19.
Located beneath the reservoir 11 is a double cylinder 12 comprising a small diameter hydraulic cylinder 25 and a large diameter pneumatic cylinder 23. A hydraulic piston 24 slides within the hydraulic cylinder 25 and is sealed against the internal cylinder wall 25 by an O-ring. Similarly, a pneumatic piston 22 slides within the pneumatic cylinder 23 and has an O-ring to seal against the internal cylinder wall of the pneumatic cylinder 23. Pistons 22 and 24 are fixed to one another by a rigid connecting rod 26. The surface area of the hydraulic piston 24 is smaller than the surface area of the pneumatic piston 22.
A firing conduit 21 extends between the fluid switch 20 and the pneumatic cylinder 23.
At the front of the hydraulic cylinder 25 there is a hydraulic firing chamber 30. A nozzle 31 extends from the hydraulic firing chamber 30 to open space.
Immediately behind the nozzle 31 is a nozzle valve 32 from which there extends a firing rod 28. The firing rod 28 is sealed through an aperture of the hydraulic firing chamber 30 and biased into the closed configuration by a nozzle valve return spring 33.
The firing rod 28 has a stopper 40 at its exposed tail end.
The fluid switch 20 comprises a manifold casing having extending longitudinally through it a manifold rod 34. Attached to the manifold rod 34 is a trigger 19. A trigger return spring 35 biases the trigger to the configuration depicted in
Attached to the trigger 19 is a pull rod 41 having at its distal end a catch 27 through which the firing rod 28 extends.
The manifold rod 34 is sealed into the manifold by a pair of O-rings 37 and 38. These O-rings are fixed with respect to the manifold casing and the manifold rod 34 slides with respect to the O-rings. The manifold rod 34 has a circumferential or annular recess 39.
The air gap between manifold 34 rod 34 and the fluid switch (manifold) casing forms the pneumatic exhaust port 36.
In the drawings, the letter “W” represents water or other hydraulic liquid and a letter “A” represents pneumatic gas such as air. For convenience, the words “water” and “air” are used.
In use, water is poured into the reservoir 11 and the cap seals the reservoir 11. The handle 14 of the priming pump 13 is reciprocated to build up pneumatic pressure in the priming conduit 16, junction 17, riser tube 18 and in the air above the water in the reservoir 11.
Hydraulic pressure in the water of the reservoir rises accordingly. As the inlet valve 29 is a one-way valve, water has flowed from the reservoir 11 into the hydraulic firing chamber 30 and into the hydraulic cylinder 25 ahead of the hydraulic piston 24. The air trapped between piston 22 and conduit 21 will be vented to atmosphere through exhaust port 36 via the gap between the O-ring 37 and the annular recess 39 in the manifold rod 34. The nozzle valve 32 is closed and continued reciprocation of handle 14 builds up hydraulic and pneumatic pressure in the system.
When trigger 19 is activated, it moves past the position of
If the pneumatic pressure behind the piston 22 is say 50 psi, the ratio of the diameter of pistons 22 and 24 will produce a correspondingly increased hydraulic pressure in the water of hydraulic cylinder 25. Such pressure might be around 90 psi. The connecting rod applies an equal and opposite force between the pistons. As the movement is dynamic in nature, there will of course be some inefficiency due to slight frictional and leakage losses. The net force on the connecting rod 26 is to the left. As a result, both pistons 22 and 24 move in unison to the left to cause a rapid jet of water through the nozzle 31.
When the trigger 19 is released as shown in
The system then reverts to the configuration depicted in
The embodiment 100 depicted in
A delivery conduit 52 located internally of the reservoir 11 feeds from the bottom and delivers water to a fluid switch 20. The fluid switch 20 is similar to that described previously, but does not require an exhaust port. The fluid switch body houses a pair of O-ring seals 37 and 38 through which the manifold rod 34 extends and with which it seals. An annular recess 39 is provided and functions much in a manner as described previously.
Upon reciprocal pumping of handle 14, pressure builds up within the reservoir 11. Due to the position of the manifold rod 34, water is allowed to pass via the annular recess 39 into the hydraulic firing chamber 30 at which a nozzle 31 is provided. A nozzle valve 32 is connected directly to the manifold rod 34 and pulls back to open the nozzle upon activation of a trigger 19 and associated components 41, 27, 28 etc. Extending from and attached to the hydraulic firing chamber 30 (via a hose clamp or similar device) is a resilient charge store in the form of a flexible bladder 50 (typically of rubber or synthetic elastic material). This accepts an additional volume of water under pressure and expands as the priming pump is primed.
When the trigger 19 is pull back as shown in
In this embodiment, a connecting bar 62 extends between the manifold rod 34 and the firing rod 28. The connecting bar 62 is attached to the trigger 19 so as to move with it. A nut 40 upon the manifold rod 34 acts upon a spring 35 which is compressed against the connecting bar 62. As the trigger 19 is activated, it pulls back on the connecting bar 62 to act upon the firing rod 28 as the spring 35 compresses. Due to the force applied by the spring 35 to the nut 40, the manifold rod 34 draws back so that the annular recess 39 pulls behind the O-ring 37 to prevent backflow of water from the firing chamber 30 to the reservoir 11. Water is therefore ejected through the nozzle 31. Due to opening of the nozzle valve 32, the spring 61 pushes the piston 60 forward rapidly to cause a strong jet of water through the nozzle. Like the previous embodiment, air is used purely to charge the firing pressure. Air does not actually passes through the fluid switch 20.
Final embodiments are depicted in
The return spring 35 compresses between the body of the pressure switch 300 and a spring-stopper 63 to bias the manifold rod 34 to the right. The manifold inlet 42 is at the left and the exit is via a firing conduit 21 that extends downward to a firing chamber 72. The manifold rod 34 has an annular recess 39 which cooperates with O-ring seals 37 and 38 in the manner described. In the configuration depicted in
In the configuration depicted in
The above fluid switch is exploited in the embodiment of
The embodiment of
Each of the embodiments of
Each embodiment also exploits a barrel-advancing mechanism comprising parts 82 and 83 interact to rotate the barrel 81 so that darts can be successively fired.
It should be noted that in each of the described embodiments, very little force is needed to motivate the manifold rod 34 due to its small diameter. Despite the relatively high pressure of the stored charge of air, this small surface area translates to a small pressure-overcoming activation force.
It should further be appreciated that modifications and alterations obvious to those skilled in the art are not to be considered as beyond the scope of the present invention.
Number | Date | Country | Kind |
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12100860.3 | Jan 2012 | HK | national |