the instant invention agitators or lifters 56 58 each include a circular peripheral rim 60 and a circular gear 62 which extends circumferencially around the back side of the rim 60 agitators or lifters 56 58 are each rotatably mounted to the basket 40 by an agitator mount assembly 64 the agitator mount assembly 64 is shown and described in u s pat no 6 220 063 and is adapted to permit the agitators 56 58 to rotate about the axes identified by the numerals 116 118 respectively the individual structure of agitator 56 is shown in fig4 and of agitator 58 is shown in fig5 each agitator 56 58 includes a concave surface 66 fig2 which is presented inwardly toward the interior of the tub 40 fig2 at the center of the concave surface 66 is a central bulge 68 and commencing from this central bulge is a helical rib or baffle 70 each helical rib 70 includes a central starting point 72 which commences adjacent the rotational axes 116 118 fig2 respectively of agitators 56 58 the helical rib or baffle 70 progresses in an outward radial direction and also in a helical direction to an outer peripheral end 74 which is located adjacent the rim 60 of the agitators 56 58 each helical rib 70 includes a first wall 76 and a second wall 78 which are tapered toward one another and which join together at a helical ridge 80 as can be seen in fig2 the first wall 76 is inclined at a less steep angle of inclination than the.