Patent ID: 6837709

Claim:
A nozzle piece for a head portion of a handpiece of a dental abrasive blasting apparatus, comprising: an inner discharge nozzle for discharging a mixture of a gaseous carrier medium and an abrasive dental powder as supplied by an associated first supply duct of a gripping member which is connected at an end with a head portion of the handpiece, a concentrically arranged outer discharge nozzle for discharging a fluid as supplied by an associated second supply duct of said gripping member, said inner and outer discharge nozzles having inner and outer discharge openings of a common central axis which by definition is inclined with respect to a longitudinal axis of the handpiece under a discharge angle in the range of 60° or more, said gripping member being provided with a closed and thusly curved surface that the first and second discharge openings of the inner and outer discharge nozzles are located close to a visual plane which is in common with the longitudinal axis of the handpiece whereby the first and second supply ducts extend in parallel along the gripping member and under an inclination angle with respect to the longitudinal axis of the handpiece which differs from 90°, said supply ducts defining axial crossing points with the common central axis of the first and second discharge openings of the inner and outer discharge nozzles which are located outside of said visual plane; wherein the first supply duct of the gripping member is provided with a slanted transition in respect to the associated inner discharge nozzle resulting in a low loss directional diversion of the supplied mixture of a gaseous carrier medium and a dental powder towards the discharge opening of the inner discharge nozzle; and wherein said slanted transition is formed by a slanted cut of the distal end of the discharge tube which is inserted into the inner bore defining the inner discharge nozzle and which protrudes with its distal end into the associated first supply duct.