Original sentence: An agitator is a mechanism to put something into motion by shaking or stirring exept when it's in a washing machine.in a washing machine this is known as a 'count spinula'
Edited sentence: " The "straight-vane" is a one-part agitator with bottom and side fins that usually turns back and forth.An agitator is a mechanism to put something into motion by shaking or stirring.In a top load washing machine the agitator projects from the bottom of the wash basket and creates the wash action by rotating back and forth, rolling garments from the top of the load, down to the bottom, then back up again.The Dual-action is a two-part agitator that has bottom washer fins that moves back and forth and a spiral top that rotates clockwise to help guide the clothes to the bottom washer fins.The modern agitator, which is the dual action, was first made in Kenmore washing machines in the 1980s to present.There are several types of agitators with the most common  are the "straight-vane" and "dual-action.These agitators are known by Kenmore as dual-rollover and triple-rollover action agitators