Abstract: The insert (2) is placed on the reception surface (10) of the interchangeable support (9). A simple movement of the piston (35) towards the right in the barrel (7) of the headstock (1) drives the cam (32) so that the lever (13) pivots and moves, introducing its nose (15) into the bore (27) of the insert, the nose drawing the insert rearwards, which is then pressed against the vertical face (11) of the support, the insert also being pressed against the horizontal face (10) of the support under the effect of the locking shoe (13), which makes it possible to fix the insert in an exactly determined position. The measuring device (12) determines this position by means of a position sensor (20) and controls the grinding operations.

Abstract: An apparatus is provided for checking the shape of a part having a portion which is a cylinder of revolution around an axis and a reference end face. The apparatus includes a base and a support arrangement mounted on the base for receiving the cylinder portion and comprising two V-shaped pieces. A positioning arrangement is provided for positioning the part axially with respect to the reference end face. A mechanism is provided for driving the part in rotation about the axis. The positioning arrangement comprises a rectilinear portion with an hemispheric end providing an abutment for the end face. The rectilinear portion is mounted slidingly on the base along a direction which forms, with respect to the axis, an angle corresponding to the half of the angle of the V-shaped pieces. An adjustment means is provided for adjusting the position of the rectilinear portion in a manner which maintains the abutment point of the hemispheric end with the end face on the axis.