Cutting Insert Protrusion Design for Chip Discharge

The patent applies local quality by creating different projection structures at different locations on the rake face. Major protrusions are positioned closer to the end cutting edge with specific heights, while minor protrusions are positioned further away with different heights. This localized differentiation allows each region to perform its specific function: major protrusions handle initial chip deformation while minor protrusions manage chip discharge, preventing the uniform vulnerability seen in stepwise projection designs.

The patent applies preliminary action by positioning the minor protrusions further from the end cutting edge than the end portions of the major protrusions. This preliminary positioning ensures that during subsequent chamfering processes after grooving and cut-off, chips are properly managed by the minor protrusions even when the major protrusions have been damaged or worn from previous operations. The structure is pre-configured to maintain chip discharge capability throughout multiple process stages.

The patent resolves this contradiction by applying local quality through the minor protrusions positioned further from the cutting edge. These minor protrusions specifically handle chip discharge during cross-feed and chamfering operations, while the major protrusions handle primary chip deformation. This localized functional assignment protects the minor protrusions from the damaging chip collisions that would affect an auxiliary projection positioned between major stages.