Patent ID: 7585139

Claim:
A boring tool, comprising: a tool body having an end face and a groove at the end face; a tool carrier mounted below the groove in the tool body; an indexable insert holder disposed in the groove wherein the holder is releasably coupled to the tool carrier using a screw, wherein the holder provides for a coarse setting of a bore diameter for the boring tool; a rotatable setting member disposed on the tool body, for transversely displacing the tool carrier; and a drive mechanism for setting the boring diameter, the drive mechanism converts a rotation of the setting member into a displacement of the tool carrier and has a differential spindle which converts the rotation of the setting member into a fine displacement of the tool carrier, wherein the setting member has a drive spindle which is connected to the differential spindle, wherein the drive spindle and the differential spindle do not rotate about each other and wherein the drive spindle has a polygonal profile rod which engages in a polygonal hole of the differential spindle, wherein the differential spindle is operatively connected to a nut which is firmly connected to the tool body, and the drive spindle being rotatably mounted with a mounting disk on the nut, the mounting disk being firmly connected to the tool body.