A laundry treating appliance is a common household device for treating articles in accordance with a treating cycle, and includes clothes washing machines and clothes dryers. A clothes washing machine cleans loads of articles, such as clothing and other fabric items, in accordance with a preprogrammed wash cycle.
For automatic washers, there are three primary sources of cleaning action: mechanical action, chemical action, and thermal action. All other things being equal, any change in one or more of these actions requires a corresponding offsetting change in the other actions to obtain the same degree of cleaning effectiveness.
Automatic washing machines can generally be categorized as horizontal axis machines or vertical axis machines. Horizontal axis machines are sometimes referred to as “front loaders” and comprise a perforated drum located within an imperforate tub, with the drum rotating about a generally horizontal axis, although the axis can be canted relative to the horizontal.
Vertical axis and horizontal axis machines differ in the manner in which they impart mechanical energy to the laundry. Vertical axis machines tend to use an impeller or agitator that directly impacts the laundry to impart mechanical energy. Horizontal axis machines impart mechanical energy primarily by the tumbling of the articles in the drum as the drum rotates.
The different manners for imparting mechanical energy results in different operational consequences. One consequence is that horizontal axis machines impart much less mechanical energy to the laundry than vertical axis machines. Another of which is that it is practical to determine the amount of mechanical energy imparted in a vertical axis machine and impractical to determine in a horizontal axis machine. The direct contact of the impeller/agitator to the laundry to impart the mechanical energy in a vertical axis machine as compared to the tumbling of the laundry in a horizontal axis machines provides for direct sensing through the forces of the impeller/agitator as a means for determining the imparted mechanical action forces, which is not possible with the horizontal axis machines.