US Patent 8646965 Concrete mixing drum fin structure

A mixing fin assembly adapted to mix and guide materials in a rotatable mixing drum of a type used in a transit concrete mixing vehicle includes a spiral mixing fin designed to extend transversely into the drum constructed of a lightweight, moldable polymeric material which is flexible and resistant to abrasion, the mixing fin includes a plurality of conjoined sections that are fit together, preferably utilizing fin locking tabs and mating fin locking sockets. A preferred way of mounting the mixing fin into mixing drums uses a spiral fin mount rail track adapted to be fixed to the interior surface of the mixing drum. A locking tab locks the upper part of the rail track into the fin structure.