Patent ID: 7497151

Claim:
Method of machining mechanical workpieces, in particular of machining the braking surfaces ( 2 , 3 ) of a brake disc ( 1 ) for vehicles, the brake disc ( 1 ) of the type that comprises a plurality of radial passages ( 4 ) defined in the thickness of the disc ( 1 ) included between opposed surfaces ( 2 , 3 ), the method comprising the steps of loading the workpiece onto a work station ( 8 ) and clamping the workpiece in a median reference plane (A) between the opposed braking surfaces ( 2 , 3 ), as well as defining the excess material thickness to be removed from each of the said surfaces, with respect to the positioning co-ordinates of the said plane in relation to a system of working axes of the station, to achieve a balanced, centered division of excess metal removed from the said surfaces ( 2 , 3 ), characterized in that it further comprises the following steps: preliminarily loading and clamping the workpiece on a handling device ( 7 ) operatively controlled by the work station ( 8 ) for the machining of the workpiece, the workpiece being gripped on the handling device ( 7 ) in the region of said median plane (A) and being clamped on the handling device ( 7 ) by engagement of respective gripping components of the handling device ( 7 ) in at least some of the said radial passages ( 4 ), the median plane (A) between the surfaces ( 2 , 3 ) being defined as a result of the positioning of the gripping components in the said passages ( 4 ), bringing said handling device ( 7 ) towards a workpiece-holder chuck ( 10 ) of the work station ( 8 ) with subsequent measurement of the positioning co-ordinates of the said median plane (A) in relation to the system of working axes, and clamping the workpiece on the chuck ( 10 ) of the work station and releasing the handling device ( 7 ) to allow both of the opposed workpiece surfaces ( 2 , 3 ) to be machined in the said work station ( 8 ) by removal of the preselected excess material thicknesses calculated in relation to the positioning co-ordinates of the said plane (A).