Patent ID: 6884070

Claim:
A powder reservoir for a dental abrasive blasting apparatus which is connected with a handpiece having a nozzle arrangement at a tip portion for discharging a jet stream of a mixture of compressed air and abrasive powder particles which is supplied from a mixing chamber that is arranged below a discharge opening of the powder reservoir, comprising: a discharge valve having a closure body which is biased towards a closing position of the discharge opening of the powder reservoir for blocking discharge of powder particles into the mixing chamber, and driving means associated with the closure body of the discharge valve for moving the closure body into a pulsed opening position alternately with respect to its closing position in which the powder particles are discharged from the powder reservoir for being mixed with a stream of compressed air which is passed through the mixing chamber at a position underneath of the discharge opening whereby a pulse frequency of the driving means which is associated with the closure body of the discharge valve is chosen such as to determine a desired dosage for the mixture of the powder particles with the compressed air, wherein the pulse frequency of the driving means is controlled in a range between 0.5 and 100 Hz at pulse width between 0 and 100%.