초록 ▼

The invention enables accurate control of particle flow with regard to feeding abrasive material to a surface. The unit does not employ a vibrator and may be used to remove undesired material from a surface. A particular application is in a dental air abrasion unit for both cleaning and cutting toot

The invention enables accurate control of particle flow with regard to feeding abrasive material to a surface. The unit does not employ a vibrator and may be used to remove undesired material from a surface. A particular application is in a dental air abrasion unit for both cleaning and cutting tooth surfaces. When used in an air abrasion dental instrument, the abrasive material is stored in a container which is separated from a mixing chamber by an orifice member. The flow of particles is electronically controlled by the differential in pressure in the container section above the particle level and the pressure below an orifice member in a mixing chamber. The resulting particle flow to the surface is substantially linear and less erratic than that of prior air abrasion instruments.

대표청구항 ▼

[ What is claimed is:] [1.] A particle feeding device comprising a container member adapted to hold abrasive particles, a mixing chamber in which a quantity of abrasive particles from said container member are combined with a carrier gas, anda substantially vibration-free pressure differential feed

[ What is claimed is:] [1.] A particle feeding device comprising a container member adapted to hold abrasive particles, a mixing chamber in which a quantity of abrasive particles from said container member are combined with a carrier gas, anda substantially vibration-free pressure differential feed system that enables the delivery of a substantially linear flow of abrasive particles over a range of carrier gas pressures, said substantially vibration-free pressure differential system including a first valve disposed above the particle level in the mixing chamber and a second valve disposed beneath said mixing chamber wherein flow of abrasive particles is caused by a discontinuous gas pressure differential between the container member holding the abrasive particles and the mixing chamber,said device further including a control mechanism which controls the rapid opening and closing of at least one of said first and second valves to create said discontinuous gas pressure differential.