Abstract: A sweeping unit has a supporting frame and at least one motor-driven rotary brush which is rotationally mounted about an longitudinal axis thereof The supporting frame is provided with supporting wheels, and a distance of the wheels from the axis of the rotary brush is controlled by an adjusting device having at least one hydraulic adjusting cylinder and a control device. A supply cylinder is hydraulically connected to the at least one adjusting cylinder and has a piston, or other signalling component, connected to a metering device and/or distance measurement device. A signal from the metering and/or distance measurement device is connected to the control unit. A working area of the supply cylinder communicates hydraulically with the at least one adjusting cylinder and has a smaller cross-sectional surface area than that of the at least one adjusting cylinder. Alternatively, the piston of the supply cylinder is connected to a mechanical adjusting drive mechanism.

Abstract: A sweeping unit which can be affixed to a carrier vehicle or a trailer, comprising a supporting frame and at least one motor-driven rotary brush which is rotationally mounted around the longitudinal axis thereof. The supporting frame is provided with supporting wheels, whereby the vertical distance of said wheels from the axis of the rotary brush can be modified by means of an adjusting device comprising at least one adjusting member and a control unit. A sensor is provided for the detection of driving torque or the driving power of the rotary brush or an associated variable, whereby the signal from said sensor is switched to the control unit. The control unit determines the working position of the adjusting member corresponding to an optimum contact surface between the brush and the ground as a function of the contact position between the ground and the adjusting member, characterized by a sharp increase in said sensor signal when the rotary brush is lowered.