involving a rotating bowl, in which a ring zone of abrasive powder is formed by centrifugal force

Full Title

Machines or devices designed for polishing or abrading surfaces on work by means of tumbling apparatus or other apparatus in which the work and/or the abrasive material is loose; Accessories therefor (abrasive blasting machines B24C3/26) > involving other means for tumbling of work > involving a rotating bowl, in which a ring zone of abrasive powder is formed by centrifugal force