Chuck for roller-cutting and winding machine

A core chuck for a web-winding machine, the core chuck comprising:

• a drive shaft extending along an axis and having an outer periphery of polygonal shape seen axially;
• a hub having a central hole with a polygonal shape substantially complementary to the shaft and fittable with limited clearance over the shaft, whereby the shaft and hub can move angularly limitedly relative to each other;
• a plurality of outwardly directed faces on the hub;
• respective jaws bearing on the faces, the faces being angled such that relative rotation between the hub and the jaws radially displaces the jaws;
• a retaining screw extending along an axis of rotation of the shaft through the hub and having a threaded shank seatable in the shaft and a head engageable axially in one direction with the hub, whereby the screw can axially retain the hub on the shaft;
• and
• a cover disk axially fixed on the hub and formed on the axis with a hole of smaller diameter than the head of the screw, the screw head being captured axially between the disk and the hub, whereby when the screw is unscrewed from the shaft its head bears on the cover disk and pushes the hub off the shaft.