Power shovel having improved front end assembly

Abstract

A power shovel comprising a support unit: a stiffleg operatively connected to the support unit for pivotal movement about a stiffleg pivot axis, the stiffleg comprising a pair of transversely spaced, longitudinally disposed side beams each having an I-shaped cross-sectional configuration including upper and lower flange portions and an interconnecting web portion, a cross-piece section interconnecting the side beam sections and a web section interconnecting the web portions of the side beam sections; a handle operatively connected to the stiffleg for pivotal movement about a handle pivot axis; a dipper mounted on the handle; a crowd system operatively connected to the handle for crowding and retracting the dipper; and a hoist system for hoisting and lowering the dipper comprising at least one upper fluid actuated rod and cylinder assembly operatively connected at a lower end thereof to the stiffleg and operatively connected at an upper end thereof to the handle on one side of the handle pivot axis, at least one lower fluid actuated rod and cylinder assembly operatively connected at a lower end thereof to the stiffleg and operatively connected at an upper end thereof to the handle on a side opposite to the operative connection of the upper end of the upper fluid actuated assembly and the handle, relative to the handle pivot axis, and apparatus for selectively supplying fluid under pressure to opposite ends of the fluid actuated assemblies to effect an extension and retraction of the rods of the fluid actuated assemblies to correspondingly effect a pivotal movement of the handle about the handle pivot axis.