US Patent 10029415 Print head nozzle for use with additive manufacturing system

A nozzle for printing three-dimensional parts with an additive manufacturing system, the nozzle comprising a nozzle body having an inlet end and a tip end offset longitudinally from the inlet end, a tip pipe for extruding a flowable material, an inner ring extending circumferentially around the tip pipe at the outlet end, an outer ring extending circumferentially around the inner ring, at least one annular recessed groove located circumferentially between the inner ring and the outer ring.