Built-in spanner for changing circular saw blades - has sliding bolt engaging and locking spindle while co-axial sleeve engages and loosens clamping nut

摘要

The outer flange (4) and blade (3) are clamped by a nut (5) screwed on the spindle (2), which has a tongue (10) machined on the end. The nut (5) is held captive on the flange by a grub screw (8) but can rotate relative to it. On the face of the nut are radial grooves (9). Aligned with the spindle axis is a stepped bolt (12) having a cross-slot (11) on its end face and sliding in a tubular housing (16) which is welded to the machine frame. The bolt is held against rotation by key (18) and tensioned way from the spindle by the spring (15). The sleeve (20) can rotate and slide on bolt (12) against the pressure of spring (22), and has radial torque arms (29). On the end face of the sleeve is a tongue (23) which can engage with the radial grooves (9) on the nut face.