Patent ID: 8113592

Claim:
A road construction machine, comprising: a machine frame; a working drum supported from the machine frame for working a ground surface or traffic surface; a plurality of ground engaging supports for supporting the construction machine on the ground surface or traffic surface; a plurality of lifting columns, each one of the lifting columns being connected between the machine frame and one of the ground engaging supports, each one of the lifting columns including two telescoping hollow cylinders and at least one piston-cylinder unit located within the telescoping hollow cylinders for adjusting a height of the lifting column so that each one of the lifting columns is individually adjustable in height relative to the machine frame, each lifting column having a lifting position corresponding to a position of one of the two telescoping hollow cylinders relative to the other of the two telescoping hollow cylinders; a plurality of lifting position measuring devices, each lifting position measuring device being coupled with elements of one of the lifting columns, which elements are capable of being displaced relative to one another in accordance with the lifting position of the lifting column in such a manner that a path signal pertaining to the lifting position of the lifting column is continuously detectable by the measuring device; and a controller operably connected to the lifting position measuring devices to receive the path signals from the lifting position measuring devices, the controller being operable to regulate the lifting positions of the lifting columns in response to the path signals detected by the lifting position measuring devices.