Abstract: An apparatus is provided for lightening of thin, flexible and shaped workpieces by removal machining of material from surfaces thereof, on a machining unit having a worktable and a counterthrust member which rests against a part of the surface of the workpiece opposed to the one on which said tool must work from time to time. The worktable includes a support member of the workpiece to be machined, and gripping mechanism which supports the workpiece during its machining independently of the support mechanism. The counterthrust mechanism includes a board movable according to several axes and carrying a plurality of supporting elements. The supporting elements can be individually translated or in groups between a draw-in position and an extended position to define a supporting plane depending on the shape of the surface of the workpiece against which the counterthrust mechanism rests. A method is also provided for mapping the workpiece surface.

Abstract: An apparatus for lightening of thin, flexible and shaped workpieces by removal machining of material from surfaces thereof, on a machining unit has a worktable and counterthrust means, which rest against a part of the surface of the workpiece opposed to the one on which said tool must work. The worktable includes supporting means of the workpiece to be machined, and gripping means designed to support the workpiece during its machining independently from said supporting means. The counterthrust means include a board movable according to several axes and carrying a plurality of supporting elements. The supporting elements can be individually translated or in groups between a draw-in position and an extended position to define a supporting plane depending on the shape of the surface of the workpiece against which the counterthrust means must rest. A method is also included for mapping the workpiece surface by means of the supporting elements.