What is the principle behind the air pump itself?
A cylinder with a valve on the side; when the piston is pulled up, the valve opens for air intake, and when the piston moves down, the valve closes, so the air can only be pushed into the tire below.
The valve design is like mentioned before, with a plate hanging inside a hole.
The plate can be covered with a layer of soft rubber, making it cover more tightly and without gaps.
This is an air pump with just one tube, which doesn't save effort and requires a lot of force when pumping.
Metal tubes are easy to make, and it's also easy to make a hole in the side and install a valve.
The front end of the tube connected to the tire is not easy to design.
The opening must be connected to a metal block, making it easy to clamp.
He will never get the shape of the clamp wrong.
The metal block connects to a thin tube as an air outlet.
There is a thicker tube outside the thin tube.
