Agitator with finned agitator blade end

An agitator, comprising:

• a hub for attachment to an agitator shaft;
• at least two agitator blades connected to the hub and extending in a radial direction for rotation about an axis, said agitator blades being angled in relation to the axis, each said agitator blade having a free end;
• and
• a fin provided in an area of the free end of the agitator blade and extending in a substantial parallel relationship to a direction of the axis away from the agitator shaft,
• wherein the agitator blade has the shape of a tetragon which is defined by
• a first side which forms a continuation of an attachment area of the agitator blade to the agitator shaft,
• a second side which extends at an angle of about 90° from an attachment-area-distal end of the first side to define the free end of the agitator blade,
• a third side which adjoins the second side and extends at an angle of greater than 90°, and
• a fourth side which adjoins the third side and extends at an angle of greater than 90°, said fourth side ending at the attachment area at a distance to the hub and positioned in opposition to an attachment area side which is extended by the first side of the tetragon.