Abstract: A system (1?) formed of a wheel comprising a rim (3?) equipped with an inflation valve (4?), a tire (2?) mounted on said rim of said wheel, and an airtight cellular foam insert (5?) placed inside the volume defined by the internal wall of the tire (2?) and the rim of the wheel (3?). The foam insert (5?) is disposed in a first compartment (A), in communication with the atmosphere via a duct (44?, 46?), and isolated from the rest of the space inside the tire casing by a device (302?) ensuring the airtight seal between the wall of said first compartment (A) and an element of the internal wall of the rim or the casing, in such a way as to form a second airtight compartment (B) communicating with the inflation valve (4?) and inflated to tire utilisation pressure. The duct for providing communication with the atmosphere (44?, 46?) is equipped with a closing device (45?) which adopts the closed position during travel and is capable of being brought into the open position between two travel phases.

Abstract: The present invention relates to a limited slip differential of the general type wherein when one of the driving wheels begins to slip or loses traction driving power is transmitted to the wheel retaining traction. The unique features of this invention involve utilizing engine input torque as the force for progressively actuating a clutch to couple differential elements to direct power to a driving wheel having traction; constantly sensing the differences between the engine input torque and the resistive torques of the driving wheels; and limiting the resistive torque of the driving wheels which can act in opposition to the clutch-applying force of the engine input torque to the differential.