Road milling machine

A road milling machine for milling a ground surface comprising:

• a machine frame;
• a milling drum housing supported from the machine frame such that an opening exists between the milling drum housing and the ground surface;
• a milling drum positioned in the milling drum housing and rotatable in a predetermined direction of rotation about an axis of rotation;
• a hold-down device to close the opening the hold-down device being configured such that a gap is defined between the milling drum and the hold-down device, and a distance between the axis of rotation and the hold-down device increases in the predetermined direction of rotation at least over a section of the gap;
• an actuator configured to raise and lower the hold-down device;
• and
• a sensor configured to detect a force acting on the hold-down device when the hold-down device encounters an obstacle;
• and
• a control unit configured such that the control unit generates a first control signal to raise the hold-down device when the force detected by the sensor is greater than a predetermined limit value, and a second control signal to lower the hold-down device when the force detected by the sensor is less than the predetermined limit value, so that the hold-down device rests on the ground surface with a predetermined contact force.

A road-milling machine, comprising:

• a machine frame;
• a milling drum supported from the machine frame and rotatable about an axis of rotation so that the drum cuts upward as the milling machine moves forward;
• a curved drum housing received about an upper part of the milling drum and defining an upper portion of a radial gap between the milling drum and the drum housing;
• a curved hold-down plate movably extending downward from the drum housing to close a forward opening between the drum housing and a ground surface and defining a lower portion of the radial gap between the milling drum and the hold-down plate;
• and
• wherein at least a part of the radial gap increases in the direction of rotation.