Manual pumping device for air blast sprayer, has lower piston sliding towards bottom and compressing air when handle is pushed, and upper piston sliding towards top and compressing air when handle is pulled

摘要

The device has an upper piston and a lower piston (9, 10) sliding in a cylinder (1), and a tubular hollow rod (6) for controlling the displacement of the pistons. The hollow rod provides communication between the interior and exterior spaces of the cylinder so as to generate a pressure difference between the spaces. The lower piston slides towards the bottom and compresses the air when a handle (5) is pushed, and the upper piston slides towards the top and compresses the air when the handle is pulled. A spring is mounted on a support (7) provided between the pistons.