(under subclass 76.3) Subject matter wherein the means for conveying comprises more than one rotary helical blade.
(1) Note. There may be a single feeder with plural screws or plural feeders each of which has a screw.
SEE OR SEARCH THIS CLASS, SUBCLASS:
156.2, for a similar feed means for materials other than rubber or heavy plastic in which material is fed into a mixing chamber by a plurality of screw conveyors.