Walking dragline excavator frames with torsion resistant tubular- web rail girders and other improvements

摘要

A walking dragline excavator construction wherein both of the frames have rail beams and wherein at least one of the rail beams comprises a continuous series of vertical tubular rail girders disposed in mutually load sharing relation and cooperating in load sharing relation with the reinforcing grid of the associated frame structure. Certain of the web plates in the reinforcing grid are oriented in a triangular pattern with apices of the triangles anchored within the rail beam. Bottom plate stiffeners are attached to the bottom plate of the base frame and also attached to certain of the web plates in the reinforcing grid within the base frame for transmitting soil pressure directly to the grid plates. The rail structures of the frames include a rail pad secured to an edge of the associated rail beam, and reentrant corner torsional shear transfer truss members are fixedly secured to the rail pad and to the rail beam and to the associated horizontal plate of the frame for transferring torsional shear directly from the plate and the rail pad into the rail beam. Horizontal stiffeners are rigidly secured to and between the rail beam of at least the base frame and certain of the reinforcing grid web plates within the frame.