Patent ID: 9540779
Date: 2017-01-10
CPC Classifications: B60G,B62D,E01C

Claim:
1. A road milling machine for the treatment of a ground surface, comprising: a machine frame; a plurality of lifting columns configured to adjust a height of the machine frame, including at least first and second rear lifting columns, the first rear lifting column having a longitudinal axis; a plurality of ground engaging units, including first and second rear ground engaging units, the first and second rear ground engaging units arranged at lower ends of the first and second rear lifting columns, respectively, at least the first rear ground engaging unit including a travel drive; a working drum connected to the machine frame and rotatable about a drum axis of the working drum; a pivot arm connected to the first rear lifting column and pivotally connected to the machine frame to pivot about a pivotal axis parallel to the longitudinal axis of the first rear lifting column, such that the pivot arm transfers the first rear ground engaging unit between a first outer end position projecting laterally relative to the machine frame and a second inner end position; a steering assembly configured to adjust a steering angle of the first rear ground engaging unit; a controller configured to control operation of the travel drive and the steering assembly; and the first rear ground engaging unit and the pivot arm being configured such that there is no separate driving device for the pivot arm, and the travel drive of the first rear ground engaging unit provides a driving force for pivoting of the pivot arm and the first rear ground engaging unit between the first outer end position and the second inner end position with the first rear ground engaging unit being in permanent contact with the ground surface during pivoting.