System PAX

Attempts have been made for a long time to create damage-resistant tires to a degree that allows the continuation of driving despite the failure. Such a solution would make it possible to eliminate the spare wheel, heavy, which takes up valuable space in the trunk and requires physical strength and certain skills from the driver when replacing it. It would be necessary to unify and standardize such elements by individual producers, like a tire and a rim, that is, creating a coherent, unified concept. The ideas so far did not meet this condition, or by interfering too deeply with the design of the wheel, or essentially a half-measure, such as e.g.. preparations introduced through the valve and sealing the tires after inflating to the desired pressure. A chance for a breakthrough may be the one developed by Michelin, and developed and introduced into serial production in cooperation with Pirelli (tires for sports vehicles) i Goodyearem/Dunlopem (EMT manufacturing technology and a patent for a tire pressure monitoring device) a system called PAX.
CONSTRUCTION AND PRINCIPLE OF OPERATION
The idea behind the PAX system is to mount the tire on the rim in this way, that it acts as a mechanical lock, protecting the foot from slipping. Thus, the basic requirement is fulfilled, placed on such solutions, allowing you to maintain control of the vehicle and continue the journey despite "catching a flat tire". The flat rim has a special design, it is indeed uniform, but its outer seat diameter is different from its inner diameter. This allows installation in the center of a flexible polyurethane insert, on which the tire remains after the air has escaped from it due to a puncture. During normal operation, the load on the vehicle causes the lock to self-tighten. After damage and pressure drop, even to zero, insert, on which the rim rests then slightly lowers the rolling resistance and makes it possible to continue driving the distance up to 200 km and below speed 80 km / h, at full load. The pressure sensor informs the driver about the condition of the tires, which, on the one hand, allows for early failure detection, and on the other – in the event of its occurrence – to inform the user about the situation and go to the website, who will repair. The PAX system works so well, that you may not even feel the change in the car's behavior, but for safety reasons it is necessary to reduce the speed.
The PAX system gives designers considerable freedom in shaping the useful space of the vehicle, by reducing the diameter of the complete circle. On the other hand, inside the rim there is more space for installing more effective brakes. There are no obstacles to using tires of different sizes on the front and rear axles. Limited (even Fr. 20%) rolling resistance reduces fuel consumption and energy losses due to tire heating, which indirectly protects the environment and extends the life of the tires.