Variable-Pitch Milling Cutter for Chatter Damping

The patent applies asymmetry by implementing unequal pitch angles between adjacent cutting edges. Specifically, the pitch angle between two directly adjacent cutting edges differs from the pitch angle between other adjacent cutting edges. This asymmetric distribution creates aperiodic excitation frequencies that effectively dampen chatter vibrations without requiring an increased number of cutting edges, thereby avoiding the increased passive forces and tool deflection that would otherwise occur.

The patent implements asymmetry in the helix angle distribution across different cutting edges. At least one cutting edge has a first helix angle while another cutting edge has a second helix angle that differs from the first. This asymmetric helix angle configuration allows each cutting edge to engage the workpiece at different angles, creating aperiodic excitation that dampens chatter vibrations without requiring uniformly high helix angles that would increase passive forces and tool deflection.

The patent applies asymmetry by varying the helix angle across different cutting edges rather than using a uniform high helix angle. This asymmetric distribution allows the cutting edges to engage the workpiece with different axial force components, creating aperiodic excitation that dampens chatter while the overall axial force remains controlled. The varied helix angles prevent the cumulative axial pull-out force that would result from all edges having high helix angles.

The patent implements asymmetry in cutting edge geometry (unequal pitch angles and varied helix angles) to reduce the axial component of cutting forces. This reduction in axial pull-out force means that conventional clamping can maintain both adequate tool security and high chuck concentricity, as the asymmetric geometry prevents the generation of excessive axial forces that would compromise concentricity when countered by strong clamping.