Abstract: Machine for precision machining, with a rod for the determination of the ctical mean axis of a hole of cylindrical general contour. The present invention relates to a machine for precision machining, in particular for the grinding of valve seatings of heat engines, which is in accordance with the described in the European Patent EP-B-No. 0,022,796. According to the invention, the pilot rod (11) comprises various annular recesses (11a), in which various rings (13) which are resiliently deformable in the radial direction are respectively mounted. The invention is applicable to all types of machines for machining necessitating the presence of a pilot rod.

Abstract: The present invention concerns a tool holder spindle for a fine-grinding hine, in particular a machine for grinding the valve seats of heat engines.According to the invention, an antivibration device (50), which is separate from the cutting tool (4), is removably mounted on the free end of the spindle (1). This device comprises a sliding block (10) arranged on the opposite side to the cutting tool (4), relative to the axis of movement of the spindle (1), and this sliding block itself has a face (11) bearing against the surface (6) to be machined, which has already been roughed down but is still to be finished.