How Bicycle Foot Powered Air Pumps Work

In this video we will be going over a physics and engineering analysis of a bicycle foot pump. The bicycle foot pump is used to take in air at the inlet and move it to the outlet while allowing for pressure to build up in the device that is hooked into the outlet which is commonly a bicycle tire.
The foot pump consisits of a pressure gauge which measures the pressure after the outlet
A piston that move up and down inside the piston chamber to move air either through the inlet or through the outlet.
2 check valves one at the inlet and one at the outlet which allow the fluid which in this case is air one direction and does not let it flow the opposite direction. The direction of flow is indicated by the arrow in the symbol.
And a spring that allows for potential energy to be stored on exhaust stroke and kinetic energy to be released on the intake stroke.
On the intake stroke or when the piston chamber volume is expanding. The inlet check valve allows for air to flow through which allows the piston chamber to be filled with air. During the intake stroke the outlet check valve remains closed. I would like to comment on the genius of putting the check valve on the piston which allows for the check valve to be in an inclosed environment. This avoids contamination of the check valve.
During the exhaust stroke the piston is fully compressed and air is pushed out of the piston chamber and through the outlet check valve. The inlet check valve remains closed while the outlet check valve is open. The air through the outlet goes to the device you are trying to fill and the pressure difference between atmospheric pressure and the outlet pressure is measured at the pressure indicator.
When the pump is not in motion both the inlet and the outlet check valves are closed. This allows for pressure to be maintained at the outlet and keep contaminants from entering at the inlet.
For this particular bicycle pump it is foot operated and acts as a second class lever when going through the exhaust stroke. This means that the fulcrum is on one side of lever arm and resistance or load is at the middle which is the piston being compressed and spring being compressed to store potential energy and the effort on the opposite end which is the force from users foot compressing the bicycle pump.
On the intake stroke the the class of lever changes to a third class lever. The fulcrum remains at the same location. The effort is now the spring which changes the potential energy to kinetic energy to raise the lever arm. The load now is the resistance from the piston intaking air.
Disclaimer
These videos are intended for educational purposes only (students trying to pass a class) If you design or build something based off of these videos you do so at your own risk. I am not a professional engineer and this should not be considered engineering advice. Consult an engineer if you feel you may put someone at risk.

[@erniemiller1953]

I was hoping for more information how the check valves work.

[@keshavgupta7604]

From where to get spares or get it repaired

[@i_am_great6344]

Which gas get inside oxygen nitrogen or carbon dioxide ???

[@VAM_Physics_and_Engineering]

it is what ever the atmospheres air mixture is at the point of entry. Assuming you are pumping up something in the open atmosphere.