Portable power tool, e.g. circular saw, with spindle lock for tool changing - has socket spanner with spigot that passes through bore of clamping screw and spindle and automatically locks spindle by entering locking hole on pitch circle of motor cooling fan

摘要

The socket spanner (21) for tightening or releasing the tool clamping screw (17) has a spigot (25) that passes through a central bore (29) of the screw and spindle and enters one of several locking holes (31) on a pitch circle of the motor cooling fan (8). In this position, the spanner simultaneously engages the locking hole and clamping screw. The fan is on the motor shaft (7), which is offset from the machine spindle by the centre distance of the final drive gear pair (10, 11). Thus, when the spigot of the spanner enters a locking hole (31), the spindle is automatically locked against rotation. USE/ADVANTAGE - Simple, low-cost design of power tool permits convenient one-handed operation.