Abstract: A mining machine includes a base, a boom, a member, and a dipper. The base includes a frame portion that is rotatable relative to the support surface about a machine axis. The boom includes a first end coupled to the base, a second end opposite the first end, and a sheave coupled to the second end of the boom. A first distance is defined between the machine axis and the second end of the boom. The member is movably coupled to the boom about a pivot point that is positioned substantially between the first end and the second end of the boom. A second distance is defined between the machine axis and the pivot point. A ratio of the second distance to the first distance is between 27% and 43%. The dipper is coupled to an end of the member and is supported by a hoist rope.

Abstract: A crowd rope take-up mechanism is mounted on the end of a shovel handle remote from the dipper bracket. The mechanism includes a cylinder with external screw threads engaged by a nut wheel. The cylinder mounts a sheave that received a loop of the crowd rope. A worm gear engages gear teeth on the outside of the nut wheel. The cylinder is restrained against rotation and the nut wheel is captured longitudinally so that rotation of the worm gear by a power wrench is translated into longitudinal movement of the cylinder and sheave. The worm gear is locked against rotation by a removable plug.

Abstract: A power shovel comprises a boom which is supported on an undercarriage and can be lifted and lowered. A hydraulically operated shovel mechanism is mounted at a front end of the boom before pivoting about a horizontal axis. The shoveling mechanism carries a pivotable shovel and at least one cable pulley. A cable hoisting gear engaged with the boom is operable to move the boom. A cable of the cable hoisting gear is trained or reeved on the cable pulley of the shoveling mechanism so that the shoveling mechanism can be moved by the hoisting gear with movement of the boom.