US Patent 8479791 Automatic tire inflation system

This is an invention for a system and method of automatically inflating the wheels of a vehicle during driving operation. When air pressure in a wheel of the vehicle decreases below a pre-determined limit, a solenoid device is activated to extend a kick-rod. As the wheel rotates, a pump mounted on the wheel strikes the kick-rod of the solenoid device, thereby causing air to be injected into the wheel. The automatic tire inflation system works by employing the mechanical energy of the rotating wheel to drive the pump upon contact with the solenoid device.