Patent ID: 8554434

Claim:
A method of automatically actuating a lockup clutch of a hydrodynamic torque converter in a self-propelling working machine such that when the lockup clutch is actuated in an engaging direction, the lockup clutch engages and thereby connects a drive input of the hydrodynamic torque converter to a drive output of the hydrodynamic torque converter to facilitate direct drive therebetween, and when both a service brake is actuated and the working machine is traveling downhill, the lockup clutch is actuated in a disengaging direction, the method comprising the steps of: using a device for recognizing when the working machine is traveling downhill to detect when the working machine is traveling downhill; actuating the lockup clutch in the engaging direction when the service brake is actuated, and maintaining engagement of the lockup clutch only if the device for recognizing when the working machine is traveling downhill detects that the working machine is traveling downhill so as to facilitate retarding of the working machine by means of both the service brake and the engine brake.