Concrete mixing drum fin structure

A mixing fin assembly adapted to mix and guide materials contained in a rotatable mixing drum of a type used in a transit concrete vehicle mixing system, the assembly comprising:

• (a) a spiral mixing fin designed to extend transversely into a drum mixing space and constructed of a lightweight moldable polymeric material which is flexible and resistant to abrasion, wherein the spiral mixing fin includes:
• a first fin section having an end that defines a fin locking tab;
• and
• a second fin section having an end that defines a mating locking socket shaped to receive the fin locking tab,
• wherein the fin locking tab and the mating locking socket extend along a helical axis of the first fin section and the second fin section;
• (b) wherein said spiral mixing fin is adapted to be attached to an interior surface of a composite polymeric mixing drum by inclusion as an integral part of a composite drum shell.

A mixing fin assembly, comprising:

• (a) a spiral mixing fin designed to extend into a drum mixing space and constructed of a lightweight moldable polymeric material which is flexible and resistant to abrasion, wherein the spiral mixing fin includes:
• a first fin section including a track locking socket and having an end that defines a fin locking tab;
• and
• a second fin section including a track locking socket and having an end that defines a mating locking socket shaped to receive the fin locking tab,
• wherein the fin locking tab and the mating locking socket extend along a helical axis of the first fin section and the second fin section;
• and
• (b) a spiral fin mount rail track including a top rim locking tab, wherein the spiral fin mount rail track is adapted to be fixed to an interior surface of a mixing drum and anchor the spiral mixing fin;
• (c) wherein the track locking sockets of the first fin section and the second fin section are shaped to accommodate the top rim locking tab thereby interlocking the spiral mixing fin with the spiral fin mount rail track.