Patent ID: 6902362

Claim:
A machine tool with at least one working unit comprising a mounting slide and a spindle mounting head, said unit extending principally longitudinally along an axis and driven, in a direction (V) parallel to said axis and to a fixed slideway by at least one linear electric motor, the working unit being connected to counterweight means, the counterweight means comprising means for compensating for the weight of the unit, wherein the counterweight means comprises an elastic element for returning the unit at least in the direction (V), the elastic return element acting in conjunction with the compensating means, the elastic return element comprising a piston and a cylinder inside which there is defined a first balancing chamber, the compensating means comprising a second balancing chamber acting as a counterbalancing chamber to the first balancing chamber, the compensating means comprising a circuit for feeding and controlling a fluid under pressure into the second balancing chamber and the circuit also comprising a proportional valve for regulating the pressure of the fluid inside the second balancing chamber.