Trigger Sprayers are extremely simple to design and rely on only a few elements to achieve their goal of spraying liquid through the bottle. When the trigger lever is pulled with a few fingers, a small pump is activated. The pump draws fluid from the bottle’s reservoir through a plastic tube. The liquid is forced through a narrow barrel and out of a small hole to a spray valve.
When the trigger is pulled, a small spring in the shroud compresses the fluid. The piston compresses the spring during trigger firing, and when it is released, it is pushed back out of the gasket. As the piston moves back and forth, it pushes the cylinder out, contributing to the pump cycle.
As a result of this extraction motion, the cylinder shrinks, forcing the fluid out in a one-way flow. The motion allows the process to continue without interruption as soon as the trigger is released. Design variations vary from pump to pump and delivery system to delivery system.