Vehicle wheel assembly with an emergency system for sudden tyre deflation

摘要

A vehicle wheel comprises a rim(1) and a pneumatic tyre(2) and is fitted with an emergency device for running on a deflated tyre. The device consists of a plastic foam(4) which when located in a pressurised tyre occupies a volume at least 10% less than the tyre inner chamber and expands to fill the chamber when a sudden tyre deflation occurs. Preferably the safety device consists of plastic beads, preferably polypropylene foam (PP) beads (4) inside a tubular cover (3) and sits as a ring on the rim (1). The emergency device (3,4) is located in the tyre (2) and mounted on the rim (1) in a pressure chamber at the normal tyre pressure and then transferred to an adjacent sluice in which the pressure is slowly reduced to atmospheric while the tyre pressure is maintained or controlled at the previous level. A further tyre, rim and emergency ring are meanwhile loaded into the empty pressure chamber from an inlet sluice.