Device for cleaning teeth

Claim 1

In a device for processing a surface of an object, such as for cleaning teeth, by directing water and a carrier gas containing an abrasive at said surface, said device including a nozzle having at least one water discharge aperture and a gas discharge aperture adjacent the water discharge aperture, said water discharge aperture being connected to a channel extending to means for connection to a source of water and said carrier gas discharge aperture being in communication with a carrier gas channel connectible to a source of gas containing the abrasive, the improvements comprising said carrier gas channel adjacent said gas discharge aperture terminating in a mixing chamber in communication with said gas discharge aperture, and an additional channel connectible to a source of abrasive-free gas discharging through an acceleration jet into said mixing chamber for discharge through said gas discharge aperture, said acceleration jet creating a flow of the abrasive-free gas in the mixing chamber toward the gas discharge aperture and creating a suction for entraining the carrier gas with the abrasive into the flow of the abrasive-free gas, said chamber having a configuration of a converging annular chamber with an axis disposed on the axis of the acceleration jet so that the abrasive-free gas being conveyed in said additional channel can be from a source having a higher acceleration energy in comparison to the carrier gas sio that the gas containing the abrasive is accelerated as it passes from said mixing chamber through said gas discharge aperture.