AU2007261483A1 - Steady stream water gun - Google Patents

Description

WO 2007/149374 PCT/US2007/014170 [00011 STEADY STREAM WATER GUN [00021 BACKGROUND [00031 The present invention is directed to a gun and more particularly, to a water gun having a more steady discharge stream of water. [00041 Toy water guns are known which utilize pressurized air or a pressurized bladder as the motive force for discharging water from the gun upon release of a nozzle valve. [0005] U.S. Patent 5,799,827 discloses a water gun having a tubular bladder arranged in a tubular holding member as the motive force for water discharge. A separate water tank is located on the gun which holds water at ambient pressure. A pump located on the gun is utilized to transfer water from the ambient pressure water tank into the bladder, expanding the bladder. Upon release of a nozzle valve using a trigger, water is ejected from the toy gun. [00061 U.S. Patent 5,878,914 discloses a similar toy water gun utilizing a water tank with water at ambient pressure, a pump and a balloon-shaped bladder located in a bladder chamber. Specialized valving means are provided to restrict air in the water reservoir from being pumped into the bladder. Water is released by pulling a trigger. An alternate type of pressure chamber is also described in which the pressure chamber is formed by a spring-loaded wall which can be compressed within a chamber. [00071 A drawback with these prior known types of arrangements is that it is difficult and costly to produce a tubular or balloon-shaped bladder economically and with the desired characteristics to provide for fluid discharge with a relatively constant pressure during the entire discharge operation. Costs are further increased by the complex construction and the requirement for a trigger mechanism and release valve. Additionally, it is often difficult for a user to pull the trigger and pump the water gun at the same time, resulting -1- WO 2007/149374 PCT/US2007/014170 in poor aim or an unintended drop-off in available pressure when shooting. However, functional triggers to release water from a water gun are provided in even the cheapest of water guns as they are generally expected by users. [0008] SUMMARY [00091 Briefly stated, the present invention provides a water gun that includes a main housing having a handle and a water ejection nozzle located thereon. A water supply tank is connected to the main housing which can be filled with water. A pump is located on the housing for pumping water from the supply tank and forcing the water into a water containment space in the pressure chamber housing having a wall defined by a piston in order to displace the piston against a biasing force of the spring. As soon as the pressure chamber receives pressurized water from the pump, it begins discharging the water through the ejection nozzle, allowing a steady stream of water to be immediately ejected from the water gun, even during pumping, without the need for the user to have the required dexterity to pull the trigger and pump at the same time. [00101 In another aspect of the invention, the nozzle is sized to be small enough that a stream of water can be ejected 20 feet or more when the pressure chamber has pressurized water therein. [0011] BRIEF DESCRIPTION OF THE DRAWINGS [0012] The foregoing summary, as well as the following detailed description of the preferred embodiment of the present invention will be better understood when read in conjunction with the appended drawings. For the purposes of illustrating the invention, there is shown in the drawings an embodiment which is currently preferred. It should be understood, however, that the invention is not limited to the precise arrangement shown. [0013] Figure 1 is a left side elevational view of a water gun in accordance with the present invention. -2- WO 2007/149374 PCT/US2007/014170 [6014 Figure 2 is a right side elevational view, partially in cross section, of the water gun shown in Figure 1 in which the water supply tank, pump, pressure chamber and nozzle are shown in detail. [0015] Figure 3 is schematic view showing the arrangement of the components of a water gun in accordance with the present invention. [00161 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [00171 Certain terminology is used in the following description for convenience only and is not considered limiting. The words "left", "right", "lower" and "upper" designate directions in the drawings to which reference is made. Additionally, the terms "a" and "one" are defined as including one or more of the referenced item unless specifically noted. [0018] Referring now to Figures 1 and 2, the water gun 10 in accordance with the present invention is shown. The water gun 10 includes a main housing, generally indicated as 12, having a handle 14 located thereon. A water supply tank 18 having an inlet 20 which can be filled with water at ambient pressure is connected to the housing 12. A screw-on or snap-on cap 22 is preferably provided on the supply tank 18. A pump 26 is connected to the housing and includes a pump handle 28 which can be moved back-and forth in order to draw water from the supply tank 18 via a conduit 30 into the pump 26, and to force water out of the pump 26 via a conduit 32 toward the pressure chamber 40. The pump handle 28 is preferably located generally on an opposite side of the housing from the handle 14. Pumps such as the pump 26 are generally known in the water gun art, and will therefore not be described in further detail. [0019] Preferably, a check valve 24 is located in or along the conduit 30 between the supply tank 18 and the pump 26 to prevent water from being forced back into the supply tank 18. A check valve 36 is located along the conduit 32 such that water cannot be forced backward from the pressure chamber 40 back to the pump 26. [0020] The pressure chamber 40' includes a pressure chamber housing 42, which is preferably cylindrical in form with a constant cross section, and -3- WO 2007/149374 PCT/US2007/014170 can be inexpensively made from a tube. A first end of the pressure chamber housing 42 is closed by an end wall 44, preferably formed as a separately attachable cap. A second end of the pressure chamber housing 42 is closed by a nozzle cap 46, which includes the nozzle 48 located at the front end thereof, which is preferably an integrally molded, one piece construction. The nozzle 48 preferably tapers from a larger open area at the end of the pressure chamber housing 42 to a smaller diameter nozzle opening. In a preferred embodiment, the pressure chamber housing 42 is a tube with a diameter of about 1.5 - 2 inches. The nozzle opening at the tip of the nozzle 48 preferably has a diameter of about 0.0625 - 0.125 inches. These sizes along with the selection of a piston spring (described below) with a sufficient spring constant are adapted to provide a strong, steady stream of water that is discharged from the nozzle to a distance of at least about 20 feet. However, the sizes can be varied to suit particular applications. [0021] A moveable piston 50 is displaceably located in the pressure chamber housing 42, and is biased toward the nozzle cap 46 by a spring 52, which preferably exerts a generally constant force on the piston 50. The piston 50 defines a movable wall that allows the water containment space in the pressure chamber 40 to increase or decrease. The front end of the piston 50 preferably includes a circumferential groove 54 in which an o-ring 56 or other seal is seated. The spring 52 can be a coil spring, as illustrated, an air spring, or any other suitable type of spring arrangement that has a sufficient k value to eject a water stream the desired distance. [00221 In use, water is pumped using the pump 26 from the supply reservoir 18 into the water containment space in the pressure chamber 40, forcing the piston 50 to be displaced against the force of the spring 52, while simultaneously shooting water from the nozzle. 48. Water is ejected from the nozzle 48 in a steady stream as the pump forces water into the pressure chamber 40 to expand the containment space and as the spring 52 forces the piston 50 back toward its neutral position when the pump is not being actuated, shrinking the containment space. Based on the relatively small -4- WO 2007/149374 PCT/US2007/014170 opening in the nozzle 48, a substantial reserve of pressurized water can be built up in the pressure chamber 40 during pumping. This provides a substantial amount of time for shooting water, which is held in a pressurized state in the pressure chamber 40, from the water gun 10. [0023] Those skilled in the art will recognize that the shape of the main housing 12 may be varied and that one or more pressure chambers 40 may be utilized in connection with the water gun 10 in accordance with the present invention. Preferably, the main housing 12 and supply tank 18 are made of molded plastic. [0024] Additionally, as shown in Figure 1, it is preferred that the main housing 12 includes a window 16 in proximity to the pressure chamber housing 42, and that the pressure chamber housing 42 is formed from a generally transparent polymeric material. A user can then observe the position of the piston 50 as well as possibly the spring 52, and therefore determine how much of a pressurized water charge remains in the pressure chamber 40. [00251 Referring now to Figure 3, a schematic diagram of a water gun 10 is shown. The pressurized water source 26' is not limited to the preferred hand pump 26 shown in Figures 1 and 2, which is used to draw water from the water supply tank 18 and force it into the pressure chamber 40. It is also possible to use other means for pressurizing the water, such as a battery operated on-board pump located on or in the housing 12, or to provide a connection to an external pressurized water source for charging the pressure chamber 40. [00261 In the preferred embodiment of the invention, no trigger or nozzle valve is provided, making the water gun simple and easy to -operate and allowing a user to continue to shoot water while pumping water into the pressure chamber 40. This allows more enjoyment for younger children and others With more limited dexterity who otherwise may become frustrated with trying to pull a trigger and pump the water gun at the same time, as required in the known prior art water guns. -5- WO 2007/149374 PCT/US2007/014170 [00271 While the preferred embodiment of the invention has been described in detail, the invention is not limited to the specific embodiments described above, which should be considered as merely exemplary. Further modifications and extensions of the present invention may be developed, and all such modifications are deemed to be within the scope of. the present invention as defined above and by the appended claims. -6-

Claims (10)

1. A water gun, comprising: a main housing; a supply tank connected to the main housing;. a pressure chamber connected to the main housing, including a pressure chamber housing with a spring loaded piston located therein; a pump for drawing water from the supply tank and forcing the water into a water containment space in the pressure chamber housing to displace the piston against a biasing force of the spring; and a nozzle in direct, uninterruptible communication with the pressure chamber to discharge water from the water gun.

2. The water gun of claim 1, wherein the pressure chamber comprises a cylindrical tube with a first closed end cap and a second end cap that includes the nozzle, and one end of the spring rests against the first end cap.

3. The water gun of claim 2, wherein the second end cap and the nozzle are integrally molded in one piece.

4. The water gun of claim 2, wherein the cylindrical tube is made of a clear polymeric material, and a window is provided in the main housing so that a position of the piston in the pressure chamber is externally observable by a user.

5. The water gun of claim 2, wherein the cylindrical tube has a diameter from about 1.5 inches to 2 inches, and the nozzle has an opening with a diameter of about 0.062 to about 0.125 inches. -7- WO 2007/149374 PCT/US2007/014170

6. The water gun of claim 1, wherein a first check valve is located between the water supply tank and the pump, and a second check valve is located between the pump and the pressure chamber.

7. The water gun of claim 1, wherein an interior of the pressure chamber with the pressurized water is in direct uninterruptible communication with the nozzle for ejecting water.

8. The water gun of claim 1, wherein the pump is battery powered.

9. The water gun of claim 1, wherein the pump is manually actuateable.

10. A method of operating a water gun, comprising: providing a water gun, a main housing, a supply tank connected to the main housing, a pressure chamber connected to the main housing, including .a pressure chamber housing with a spring loaded piston located therein, a pump for drawing water from the supply tank and forcing the water into the pressure chamber housing to displace the piston against -a biasing force of the spring, and a nozzle in direct, uninterrupted communication with a containment space of the pressure chamber, to discharge water from the water gun; a user holding the housing with a first hand and actuating the pump with a second hand; simultaneously ejecting water from the nozzle and displacing the spring loaded piston in the pressure chamber with pressurized water from the pump to create a pressurized water reservoir; and continuing to eject water from the nozzle of the water gun after ceasing to actuate the pump. -8-