Motor-powered tool e.g. polishing tool, has working speed control circuit with speed setting device adjustable by user, position maintenance mechanism, and switch for fixed operating speed with at least two positions

摘要

The tool has a speed setting device adjustable by the user with a position maintenance mechanism and a switch for a fixed operating speed coupled to the speed setting device and with at least two positions. The first position causes fixed speed to be set by the speed setting device and the second position causes the fixed speed to be set to a preset speed The preset working speed is set by the tool manufacturer or by the user.