US Patent 7934847 Power tool with light unit

A power tool includes a motor as a drive power source, a body housing the motor and having an end output unit for chucking an end tool, a handle grip connected to the body; and a light unit disposed to one of the handle grip and the body, and having a light-emitting element for providing illumination near the end tool. The light unit comprises switch means for switching the light-emitting element on and off, and an off circuit for automatically turning the light-emitting element off at a predetermined time after the light-emitting element turns on.