Shovel having a wristing dipper

Abstract

A rope shovel includes a wristing dipper arrangement. The shovel comprises a base, a boom extending from the base, the boom having a first end attached to the base and a second end remote from the base. The shovel further comprises a pulling mechanism mounted on the second end of the boom and a boom attachment pivotally mounted on the boom and attached to a dipper, the boom attachment including an actuator coupled to the dipper.

What is claimed is: 
     
         1 . A mining shovel comprising:
 a base including a hoist drum for paying out and reeling in a hoist rope;   a boom including a first end coupled to the base and a second end opposite the first end, the hoist rope extending over the second end of the boom;   a boom attachment movably coupled to the boom, the boom attachment rotatable relative to the boom about a first pivot location, the first member including a first end and a second end;   an excavating member including a first portion and a second portion, the excavating member defining a material discharging opening and a material receiving opening, the first portion pivotably coupled to the second end of the boom attachment, the second portion pivotably coupled to the first portion to selectively close the material discharging opening; and   a pivot actuator for moving the excavating member relative to the second end of the boom attachment, the pivot actuator including a first end coupled to the boom attachment.   
     
     
         2 . The shovel of  claim 1 , wherein the excavating member is coupled to the hoist rope passing over the second end of the boom. 
     
     
         3 . The shovel of  claim 2 , wherein the hoist rope exerts a tension force on the excavating member, thereby inducing a moment on the excavating member to rotate about the second end of the boom attachment in a first direction. 
     
     
         4 . The shovel of  claim 3 , wherein the pivot actuator is a hydraulic cylinder such that extension of the cylinder causes the excavating member to rotate about the second end of the boom attachment in the first direction. 
     
     
         5 . The shovel of  claim 3 , wherein the tension force acts on the excavating member at a first joint and the excavating member is pivotably coupled to the second end of the boom attachment at a wrist joint that is offset from the first joint. 
     
     
         6 . The shovel of  claim 5 , wherein operation of the pivot actuator changes the offset distance between the wrist joint and the first joint, thereby changing the moment induced by the tension force acting on the excavating member. 
     
     
         7 . The shovel of  claim 1 , wherein the first portion of the excavating member is pivotably coupled to the boom attachment at a wrist joint, and wherein the pivot actuator further includes a second end coupled to the excavating member at a second joint that is offset from the wrist joint. 
     
     
         8 . The shovel of  claim 1 , wherein the excavating member is a dipper, the first portion being a dipper body and the second portion being a dipper door. 
     
     
         9 . A mining shovel comprising:
 a boom including a first end and a second end opposite the first end;   a hoist rope extending substantially along the boom and passing over the second end of the boom;   a handle moveably coupled to the boom, the handle rotatable relative to the boom about a first pivot location, the handle including a first end and a second end;   an excavating member pivotably coupled to the second end of the handle at a wrist joint, the excavating member coupled to the hoist rope passing over the second end of the boom, the hoist rope exerting a tension force on the excavating member at a position that is offset from the wrist joint, the tension force inducing a moment on the excavating member to rotate the excavating member about the wrist joint in a first direction; and   an actuator including a first end coupled to the handle and a second end coupled to the bucket proximate a lower end of the excavating member, extension of the pivot actuator causing the excavating member to rotate about the wrist joint in the first direction.   
     
     
         10 . The shovel of  claim 9 , wherein the excavating member further includes a first portion and a second portion, the second portion having a pair of side walls and a lower wall extending between the side walls, the second portion defining a material receiving opening and a material discharging opening opposite the material receiving opening, the first portion being pivotably coupled to the first portion to selectively close the material discharging opening. 
     
     
         11 . The shovel of  claim 10 , wherein the excavating member further includes a plurality of teeth positioned along at least a portion of an edge of the lower wall proximate the material receiving opening. 
     
     
         12 . The shovel of  claim 8 , wherein extension of the pivot actuator changes an offset distance between the tension force and the wrist joint, thereby changing the moment induced by the tension force. 
     
     
         13 . The shovel of  claim 8 , wherein the excavating member is a dipper, the first portion being a dipper body and the second portion being a dipper door.