Patent ID: 8002065

Claim:
In a tractor-trailer combination including (i) a semitrailer tractor having (a) a front axle and (b) at least one drive axle having a predefined nominal axle load, (ii) a semitrailer having (c) a first axle and (d) at least one second axle, and (iii) an axle load adjusting device, including an axle center height drive for said first axle adapted to change a drive-axle axle load acting on said drive axle by adjustment of a center height of said first axle, said axle load adjusting device being adapted to automatically switch into a starting assistance mode in which a second-axle axle load acting on said at least one second axle is increased to a starting-assistance axle load that is less than a predefined maximum axle load, an axle center height controller adapted to automatically sense actuation of an off-road starting sensing device, and to increase said second-axle axle load to an off-road starting axle load that is greater than said predefined maximum axle load when said off-road starting sensing device is actuated.