Stephen G Brush, Harold Gruen, John D Peterson, Charles H Piltzecker: Power feeder mechanism having means for moving powder to a gas carrier. Avco Corporation Cincinnati OH, Charles M Hogan, Abraham Ogman, February 23, 1971: US3565296 (1 worldwide citation)

The disclosure shows a feeder for powdered metals, or the like, which are used in flame-spraying systems. Powdered metal is placed in a rotating, sealed drum. Pressurized gas is fed through a carburetor into the drum. A metered amount of material is entrained in gas entering an upwardly facing port. ...