Abstract: A tool head having a first slide fitted with a tool holder as well as a second slide for eliminating the unbalance effect created by the off-centering of the first slide. An actuating device that can be actuated longitudinally that is able to control the radial displacement of the two slides. Each of these slides is provided with a pressing device for pressing the slide against an oblique support surface of the actuating device. The force exerted by each of the pressing devices is determined, so as to be greater than the centrifugal force exerted on each slide and in a direction opposed to that of the centrifugal force. This force is determined so that the resultant force of all forces exerted on each slide is constant.

Abstract: The device for displacing a platform includes two carriages driven, simultaneously or separately, on guiding rails oriented along an axis X. The two carriages carry a platform mounting slides engaged with slideways on the carriages. At least one of the slides of the platform carriage and at least one of the slideways of the carriage is oriented at an angle other than 90° relative to an axis X. The displacement along any direction of a plane comprised of the axes X and Z of a tool holder spindle or work piece spindle mounted on the platform can be obtained only by the relative or simultaneous moving of the two carriages on the guiding rails.