| 摘要 |
<p>The invention provides a mandrel comprising a shaft (1) the forward end of which has the shape of a forward pointing truncated cone (7), an expanding sleeve (15) constituted by a ring provided with longitudinal slits designed to slide over said conical forward end (7), and a piston (8) which is guided in a cylindrical bore provided along the axis of the mandrel shaft (1), from which it projects forwards, with the sliding of said piston (8) driving said sleeve (15) so as to control the gripping or the releasing on said mandrel of a workpiece to be machined. According to the invention, the forward end of the piston (8) has the shape of a rearward pointing truncated cone (12), and the inner wall of the sleeve (15) has the shape of two successive truncated cones (17, 18) orientated mirror image fashion, with the apex angle of the forward cone (18) of the sleeve (15), which is capable of mating with said cone (12) of the piston, being greater than the apex angle of the rear cone (17) of the sleeve (15), which is capable of mating with said cone (7) of the shaft (1).Application to the gripping of workpieces having a cylindrical or conical bore.</p> |
