Washing machine agitator having helical rib and method for using same

Abstract

A washing machine includes a washing machine cabinet. A wash basket is mounted within the washing machine cabinet. A first agitator is mounted in the basket for rotation about a first agitator axis that extends in a direction different from the rotational axis of the wash basket. First agitator includes a first helical rib thereon for engaging and agitating the materials to be washed within the wash basket. A second agitator with a second helical rib may also be contained within the wash basket.

What is claimed is:  
     
         1 . A washing machine comprising: 
 a washing machine cabinet;    a wash basket mounted within the washing machine cabinet for rotation about a wash basket axis, the wash basket having an access opening for placing materials to be washed within the wash basket;    a first agitator mounted in the basket for rotation about a first agitator axis that extends in a direction different from the wash basket axis;    the first agitator having a first helical rib thereon for engaging and agitating the materials to be washed within the wash basket when the first agitator is rotating about the first agitator axis.    
     
     
         2 . A washing machine according to  claim 1  comprising a second agitator mounted within the basket for rotation about a second agitator axis extending in a direction different from the wash basket axis and the first agitator axis, the second agitator having a second helical rib thereon for engaging and agitating the materials to be washed within the wash basket when the second agitator is rotating about the second agitator axis.  
     
     
         3 . A washing machine according to  claim 2  wherein the first and second agitators each include a concave surface and the first and second helical ribs protrude from the concave surfaces of the first and second agitators respectively.  
     
     
         4 . A washing machine according to  claim 3  wherein an agitator drive mechanism is connected to the first and second agitators for driving the first and second agitators in opposite rotational directions.  
     
     
         5 . A washing machine according to  claim 4  wherein the first and second helical ribs extend in first and second helical directions that are opposite to one another.  
     
     
         6 . A washing machine according to  claim 5  wherein each of the first and second helical ribs commence adjacent the first and second agitator axes respectively and extend in an outward radial helical direction therefrom.  
     
     
         7 . A washing machine according to  claim 6  wherein the basket includes a concave interior surface and each of the first and second agitators includes a convex surface opposite from the concave surface thereof, the convex surfaces of the first and second agitators facing toward the concave interior surface of the basket.  
     
     
         8 . A washing machine according to  claim 1  wherein the first agitator is circular in shape and includes an outer rim, at least one wedge shaped member being on the agitator adjacent the outer rim for facilitating turnover of fabrics being washed.  
     
     
         9 . An appliance agitator comprising: 
 an agitator member having a concave surface, an opposite convex surface, and a peripheral edge;    a helical rib protruding from the concave surface and extending in an outward radial helical direction from a central starting point to an outer end point adjacent the peripheral edge of the agitator member.    
     
     
         10 . An appliance agitator according to  claim 9  wherein the peripheral edge extends approximately in a circle.  
     
     
         11 . An appliance agitator according to  claim 9  wherein the starting point of the helical rib is at the approximate center of the circle.  
     
     
         12 . An appliance agitator according to  claim 9  and further comprising at least one wedge shaped member on the agitator member adjacent the peripheral edge thereof for facilitating turnover of the fabrics being washed.  
     
     
         13 . A washing machine comprising: 
 a cabinet;    a washing basket mounted within the cabinet for rotation about a basket axis, the washing basket having a basket cavity and concave interior surface facing toward the basket cavity;    a first agitator having a concave surface, an opposite convex surface, and a peripheral edge,    the convex surface facing toward the concave interior surface of the washing basket and the concave surface of the first agitator facing toward the basket cavity;    the first agitator being mounted for rotation relative to the washing basket about a first agitator axis;    a first helical rib protruding from the concave surface of the first agitator, the first helical rib commencing at an inner location and progressing in a helical direction and an outward radial direction therefrom.    
     
     
         14 . A washing machine according to  claim 13  and further comprising a second agitator within the basket cavity having a concave surface facing the basket cavity, a convex surface facing the concave surface of the washing basket, and a peripheral edge, the second agitator being mounted for rotation relative to the washing basket about a second agitator axis, a second helical rib protruding from the concave surface of the second agitator.  
     
     
         15 . A washing machine according to  claim 14  wherein the second helical rib commences at an inner location and progresses in a helical direction and an outward radial direction therefrom.  
     
     
         16 . A method for operating a washing machine having a basket for containing the fabrics to be washed, and first and second agitators mounted within the basket for rotation about first and second agitator axes respectively, the method comprising: 
 rotating the first and second agitators about the first and second agitator axes respectively;    lifting the fabrics being washed with first and second helical ribs on the first and second agitators during rotation of the first and second agitators about the first and second agitator axes respectively;    dropping the fabrics from the first and second helical ribs after the first and second helical ribs lift the fabrics whereby the fabrics will turn over and fall within the basket.    
     
     
         17 . A method according to  claim 16  and further comprising rotating the first agitator in one direction about the first agitator axis and rotating the second agitator about the second agitator axis in a second direction opposite from the first direction.  
     
     
         18 . A method according to  claim 17  and further comprising reversing the rotational direction of the first and second agitators.  
     
     
         19 . A method according to  claim 17  wherein the first and second helical ribs each include first and second side walls angling toward one another and being joined together at an elongated helical rib, the first side wall having a first angle of inclination and the second side wall having a second angle of inclination that is steeper than the first angle of inclination, the method further comprising rotating the first and second helical ribs about the first and second agitator axes, respectively in a rotational direction that causes the first side walls of the first and second helical ribs to engage and lift the fabrics.  
     
     
         20 . A method according to  claim 19  and further comprising reversing the rotational directions of the first and second helical ribs so that the second side walls of the first and second helical ribs engage and lift the fabrics.