PROCEDE ET DISPOSITIF D'INTRODUCTION DE BARRES PROFILEES DANS DES TOURS

摘要

A screw machine has a headstock provided with an openable and closable chuck rotatable at high speed and having a throughgoing aperture of cross-sectional shape complementary to that of a bar to be machined in the screw machine. A feed apparatus for this machine comprises means for detecting the rotational speed of the chuck and for generating a speed output when the rotational speed lies within a predetermined range. In addition, a pusher is provided which only advances the bar into the aperture of the chuck after generation of the output. This pusher is engageable with an abutment that is only displaced out of its way when the speed output is generated. Furthermore the apparatus generates a position output when the bar is properly in place and has a timer which withdraws the bar from the chuck if within a predetermined time limit after generation of the speed output the position output is not generated, indicating that the apparatus is unable to load the bar.