Dipper door trip assembly

Abstract

A dipper door trip assembly includes a dipper, a dipper door pivotally coupled to the dipper, a linkage assembly including a sliding latch bar disposed at least partially in the dipper door, and a latch keeper coupled to the dipper. The latch keeper includes a roller that engages and disengages the latch bar.

1 . A dipper door trip assembly comprising:
 a dipper;   a dipper door pivotally coupled to the dipper;   a linkage assembly including an elongate, sliding latch bar disposed at least partially in the dipper door, wherein the sliding latch bar is configured to slide linearly relative to the dipper door;   a latch keeper coupled to the dipper; and   a roller assembly configured to facilitate sliding of the latch bar as the latch bar slides linearly with respect to the dipper door, wherein at least a portion of the roller assembly is configured to be in direct contact with the latch bar when the latch bar slides through the latch keeper.   
     
     
         2 . The dipper door trip assembly of  claim 1 , wherein the roller assembly is fixed to the latch keeper, wherein the roller assembly includes a roller, and wherein the roller is configured to directly contact and roll across a surface of the latch bar as the latch bar slides through the latch keeper. 
     
     
         3 . The dipper door trip assembly of  claim 1 , wherein the roller assembly is a separate, replaceable component of the dipper door trip assembly. 
     
     
         4 . The dipper door trip assembly of  claim 1 , wherein the roller assembly includes a metal pin and roller journals, wherein the metal pin is a roller configured to rotate about the roller journals. 
     
     
         5 . The dipper door trip assembly of  claim 4 , wherein the roller journals are fastened to the latch keeper. 
     
     
         6 . The dipper door trip assembly of  claim 1 , further comprising a trip motor coupled to the linkage assembly. 
     
     
         7 . The dipper door trip assembly of  claim 6 , wherein the linkage assembly includes an upper link arm coupled to the trip motor, the upper link arm pivotally coupled to the dipper door at a pivot point. 
     
     
         8 . The dipper door trip assembly of  claim 7 , wherein the linkage assembly further includes a connecting rod coupled to the upper link arm. 
     
     
         9 . The dipper door trip assembly of  claim 1 , further comprising a latch bar housing disposed within the dipper door, wherein the latch bar housing is sized and shaped such that the latch bar is configured to slide linearly within the latch bar housing, wherein the latch bar housing includes an opening through which a portion of the latch bar is configured to extend linearly. 
     
     
         10 . A mining machine comprising:
 a boom;   a handle coupled to the boom; and   the dipper door trip assembly of  claim 1 , wherein the dipper is coupled to the handle.   
     
     
         11 . The mining machine of  claim 10 , further comprising tracks, a turntable coupled to the tracks, and a revolving frame coupled to the turntable, wherein the boom is coupled to the revolving frame. 
     
     
         12 . The dipper door trip assembly of  claim 1 , further comprising an insert coupled to the latch bar.