Method of and apparatus for truing cutter heads

An apparatus for radially truing cutting tools of the type comprising stick-type cutting blades releasably mounted in a cutter head, said apparatus comprising:

• a machine base,
• a tool support mounted on said machine base, said tool support comprising a tool spindle indexable about a tool axis,
• a probe support mounted on said machine base, said probe support being positionable with respect to said tool support along three mutually orthogonal axes,
• at least one probe mounted to said probe support, said at least one probe being angularly positionable on said probe support and movable in a first direction to define probe offset and in a second direction to define in/out feed motion,
• a blade stop mounted to said probe support, said blade stop being movable toward and away from said tool support along an axis.

A method of radially truing cutting tools of the type comprising stick-type cutting blades releasably positioned in a cutter head, said cutting blades having a cutting edge and a cutting side relief surface oriented at a relief angle, said method comprising:

• providing a truing apparatus comprising a measuring probe and a cutting tool spindle,
• mounting said cutting tool to said spindle,
• positioning said probe with respect to said cutting side surface of a cutting blade whereby said probe is adjacent said cutting side surface, said positioning comprising indexing said cutter by an amount to position said cutting edge adjacent said probe plus indexing said cutter by an additional amount equal to said predetermined relief angle to position said probe perpendicular to the lengthwise direction of said cutting side relief surface,
• probing said cutting side relief surface to determine a position reading,
• recording said position reading,
• comparing said recorded position with a predetermined position, and,
• (a) if said recorded position is within a pre-set tolerance range of said predetermined position,
• indexing said cutting tool to another cutting blade, or,
• (b) if said recorded position is outside of a pre-set tolerance range of said predetermined position,
• axially adjusting the position of said cutting blade in said cutter head by an amount to reposition said cutting side within said preset tolerance range.

A method of determining the position of at least one surface of a stick-type cutting blade projecting from a surface of a cutter head, said at least one cutting blade having a cutting edge, a cutting side relief surface oriented at a first relief angle, a clearance side relief surface oriented at a second relief angle, and a front rake face oriented at a rake angle, said method comprising:

• providing an apparatus comprising a cutter spindle and a measuring probe capable of movement in a first direction defining probe offset travel,
• mounting said cutter head to said spindle,
• positioning said probe with respect to a surface of said cutting blade whereby said surface is substantially parallel to said first direction,
• probing said surface to determine a position reading,
• recording the position of said surface.