Patent ID: 7131557

Claim:
A toy water gun, comprising: a housing including a handle with a trigger and a water ejection nozzle located thereon; a water supply tank connected to the housing which can be filled with water; a water pressure chamber that includes at least one fixed wall, a first end wall, and a moveable wall which substantially sealingly engages the at least one fixed wall and is slidable away from the first end wall as water is pumped into the water pressure chamber and toward the first end wall as water is discharged; an air pressure chamber located on an opposite side of the moveable wall from the water pressure chamber that is pressurizable with compressed air to bias the moveable wall toward the first end wall; a pump and a selector valve assembly connected thereto which, in a first state, allows air to be pumped by the pump into the air pressure chamber for pressurizing the air pressure chamber with compressed air and, in a second state, places the pump in communication between the water supply tank and the water pressure chamber to allow water to be pumped by the pump from the supply tank to the water pressure chamber; and a release valve in fluid communication with the water pressure chamber so that actuation of the release valve allows a stream of water to be ejected from the nozzle due to the compressed air acting on the moveable wall.