Self-locking screw for attaching saw-blade to mandrel, has set of contact surfaces, screw head provided with slots into which balls engage during tightening of screw, and pressure spring safely twisted against lock unit

摘要

The screw has a set of contact surfaces arranged over partial areas of the screw. The contact surfaces, a pressure spring, and a lock unit are provided in the screw. A locking disk is provided with associated slots (5a, 5b) in to which two balls are firmly inserted. A screw head (1) is provided with slots in to which the balls engage during tightening of the screw. The pressure spring can be safely twisted against the lock unit. An independent claim is also included for a self-locking fastening arrangement with a self-locking screw.