Spray arm assembly for dishwasher appliances

Abstract

Dishwasher appliances and spray arm assemblies for dishwasher appliances are provided. An assembly includes an indexing assembly disposed between a conduit and a plurality of spray arms. The indexing assembly includes a disk rotatable about an axis and movable along an axial direction between a first position and a second position, the disk defining an aperture and a channel and comprising a plurality of cams projecting into the channel. The indexing assembly further includes a biasing element configured to urge the disk into the first position, and a boss assembly, the boss assembly comprising a boss extending into the channel of the disk, the boss defining a plurality of guide elements. The guide elements and cams are configured to interact such that movement of the disk along the axial direction between the first position and the second position causes the disk to rotate about the axis.

What is claimed is: 
     
         1 . A dishwasher appliance, comprising:
 a tub that defines a wash chamber for receipt of articles for washing;   a spray arm assembly for directing a fluid flow into the wash chamber, the spray arm assembly comprising:
 a plurality of spray arms, the plurality of spray arms comprising a first spray arm and a second spray arm; 
 a conduit in fluid communication with the plurality of spray arms; 
 an indexing assembly disposed between the conduit and the plurality of spray arms, the indexing assembly operable to selectively flow fluid to the first spray arm and the second spray arm, the indexing assembly comprising:
 a disk rotatable about an axis and movable along an axial direction between a first position and a second position, the disk defining an aperture and a channel and comprising a plurality of cams projecting into the channel; 
 a biasing element configured to urge the disk into the first position; and 
 a boss assembly, the boss assembly comprising a boss extending into the channel of the disk, the boss defining a plurality of guide elements, wherein the guide elements and cams are configured to interact such that movement of the disk along the axial direction between the first position and the second position causes the disk to rotate about the axis. 
 
   
     
     
         2 . The dishwasher appliance of  claim 1 , wherein the disk is movable into the second position by fluid flowed through the inlet assembly and into contact with the disk. 
     
     
         3 . The dishwasher appliance of  claim 1 , wherein the aperture is aligned to flow fluid to one of the plurality of spray arms when the disc is in the second position. 
     
     
         4 . The dishwasher appliance of  claim 1 , wherein the boss defines a first recess into which a first end of the biasing element is received. 
     
     
         5 . The dishwasher appliance of  claim 1 , wherein the disk defines a second recess within the channel, and wherein a second end of the biasing element is received into the second recess. 
     
     
         6 . The dishwasher appliance of  claim 1 , wherein the boss is cylindrically-shaped and defines a circumferential direction and a radial direction, wherein the guide elements of the boss project along the radial direction and are spaced apart from each other along the circumferential direction. 
     
     
         7 . The dishwasher appliance of  claim 6 , wherein the guide elements each include a contact face positioned at a non-zero angle from the axial direction. 
     
     
         8 . The dishwasher appliance of  claim 1 , further comprising an inlet assembly disposed between and in fluid communication with the conduit and the plurality of spray arms. 
     
     
         9 . The dishwasher appliance of  claim 1 , wherein the biasing element comprises a needle bearing and a spring, the spring generally surrounding the needle bearing. 
     
     
         10 . The dishwasher appliance of  claim 1 , wherein the disk comprises a plurality of apertures and the plurality of spray arms comprises a plurality of first spray arms and a plurality of second spray arms. 
     
     
         11 . A spray arm assembly for a dishwasher appliance, comprising:
 a plurality of spray arms, the plurality of spray arms comprising a first spray arm and a second spray arm;   a conduit in fluid communication with the plurality of spray arms;   an indexing assembly disposed between the conduit and the plurality of spray arms, the indexing assembly operable to selectively flow fluid to the first spray arm and the second spray arm, the indexing assembly comprising:
 a disk rotatable about an axis and movable along an axial direction between a first position and a second position, the disk defining an aperture and a channel and comprising a plurality of cams projecting into the channel; 
 a biasing element configured to urge the disk into the first position; and 
 a boss assembly, the boss assembly comprising a boss extending into the channel of the disk, the boss defining a plurality of guide elements, wherein the guide elements and cams are configured to interact such that movement of the disk along the axial direction between the first position and the second position causes the disk to rotate about the axis. 
   
     
     
         12 . The spray arm assembly of  claim 11 , wherein the disk is movable into the second position by fluid flowed through the inlet assembly and into contact with the disk. 
     
     
         13 . The spray arm assembly of  claim 11 , wherein the aperture is aligned to flow fluid to one of the plurality of spray arms when the disc is in the second position. 
     
     
         14 . The spray arm assembly of  claim 11 , wherein the boss defines a first recess into which a first end of the biasing element is received. 
     
     
         15 . The spray arm assembly of  claim 11 , wherein the disk defines a second recess within the channel, and wherein a second end of the biasing element is received into the second recess. 
     
     
         16 . The spray arm assembly of  claim 11 , wherein the boss is cylindrically-shaped and defines a circumferential direction and a radial direction, wherein the guide elements of the boss project along the radial direction and are spaced apart from each other along the circumferential direction. 
     
     
         17 . The spray arm assembly of  claim 16 , wherein the guide elements each include a contact face positioned at a non-zero angle from the axial direction. 
     
     
         18 . The spray arm assembly of  claim 11 , further comprising an inlet assembly disposed between and in fluid communication with the conduit and the plurality of spray arms. 
     
     
         19 . The spray arm assembly of  claim 11 , wherein the biasing element comprises a needle bearing and a spring, the spring generally surrounding the needle bearing. 
     
     
         20 . The spray arm assembly of  claim 11 , wherein the disk comprises a plurality of apertures and the plurality of spray arms comprises a plurality of first spray arms and a plurality of second spray arms.