Water gun
Wolff's June 30, 1896 patent,[2][3] the oldest known reference to a squirt gun is dated thirty-five years prior, with General William T. Sherman's 1861 quote regarding the effort to quell secession: "Why, you might as well attempt to put out the flames of a burning house with a squirt-gun.
"[4] For several years in the United States and Canada, import regulations and domestic laws have required squirt guns to be made of clear or tinted transparent plastic to make them harder to mistake for actual firearms.
[1] This design has inherent limitations regarding the amount of pressure that one can achieve (fully dependent on the user's hand gripping strength) as well as the need to refill after each shot.
Many early small water guns used the same trigger based pumping mechanism used for spray bottles.
With the aid of two check valves, often using small ball bearings, fluid is drawn into the pump from a reservoir, then forced out the nozzle upon squeezing the trigger.
Increasing pump volume would require more user effort to push the fluid out, making larger designs impractical.
Stream performance was often not improved, but the motor removed the need to pump, which made the toys popular.
[citation needed] The air pressurized reservoir was introduced by the Cosmic Liquidator but made famous by the Super Soaker brand of water guns.
As well, unlike the methods noted above, this air pressure system allows production of a uniform, continuous stream of water.
Akin to pre-pressurizing the Separate Pressure Chamber water guns, the split air/water pressure chamber takes this one step further by preventing the accidental, undesired release of the pre-pressurized air by keeping it separated from the water by a sliding piston divider.
The Waterball series has a spring-based catapult mechanisms for launching balls of water out of its nozzle.
[12] Additionally, the Super Soaker Quick Blast employs a spring-based firing chamber to propel its stream forward.
[13] Peristaltic pump systems have also been used in some water guns models, most notably the original Shield Blaster water guns by Mattel In this system, a rotary pump is used to move rollers along a compressible piece of tubing.
True continuous streams cannot be produced since the physical presence of the rollers means there will be partial gaps in the flow.
In (A), pushing the trigger (1) expels the cylinder's contents through the nozzle; releasing it refills it from the reservoir (2).
In (B), pumping the piston (3) forces air into the reservoir (4), increasing its pressure; opening the valve (5) expels the reservoir's contents.
In (C), pulling out the piston (6) draws in water from the unpressurised reservoir (7), whereas pushing it in pressurises the firing chamber (8); triggering the valve (9) expels the chamber's contents.
In (D), the firing chamber is replaced with an elastic bladder (8a) which exerts more uniform pressure on the water.