Dipper handle assembly for a power shovel

Abstract

An improved yoke for a dipper handle assembly used on a power shovel is provided. The yoke is constructed at least in part of a transition portion and associated lugs that are manufactured of a forged material as opposed to castings. Accordingly, the yoke is less prone to failure and easy to repair in the field.

Description

[0001]This application is a continuation of U.S. patent application Ser. No. 16 / 743,802, filed Jan. 15, 2020, now issued as U.S. Pat. No. 10,865,541 on Dec. 15, 2020, which in turn claims the benefit of U.S. Provisional Patent Application No. 62 / 798,199, filed Jan. 29, 2019, both of which are incorporated by reference herein in their entireties.FIELD OF THE INVENTION[0002]Embodiments of the present invention are generally concerned with dipper handle assemblies used by power shovels. More specifically, an improved dipper handle yoke is disclosed.BACKGROUND OF THE INVENTION[0003]Power shovels, which are also known as stripping shovels, front shovels, electric mining shovels, or rope shovels, are common in the mining industry. FIG. 1 shows an example of a power shovel 1 manufactured by Caterpillar® as their Model 7495. The dipper 2, i.e. the shovel, is supported at an upper and by cables 6 operatively interconnect to a boom assembly 10. The boom assembly 10 is configured to selectivel...

AI Technical Summary

Benefits of technology

[0008]It is one aspect of some embodiments of the present invention to provide a yoke comprised of a forged transition portion and forged lugs interconnected by a plurality of plates. One advantage of this configuration is that the grain structure of the forged components can be precisely controlled to provide increased tensile strength and fatigue resistance. Those of ordinary skill in the art will appreciate yoke transition portions are traditionally cast because they possess areas of varying thicknesses and of complex shapes, which makes the component difficult to forge. Counter to conventional wisdom, embodiments of the present invention replace the previously-cast components with forgings to eliminate material defects inherent to casting processes. Accordingly, a yoke having a stronger transition portion is provided, wherein material grain structure is selectively controlled to coincide with the direction of typical yoke bending loads. Providing a yoke with forged components facilitates repair as preheat requirements are reduced and, thus, weldability is improved.

[0009]It is another aspect of some embodiments of the present invention to provide a yoke that can be used for hydraulic and rope crowd power shovels. More specifically, the yoke of one embodiment designed for rope crowd applications is configured to receive a forged insert that allows the yoke to be used with hydraulic crowding power shovels. The insert includes a bore for interfacing with an end of the hydraulic cylinder. One end of the insert abuts a shoulder provided within the yoke, wherein an opposite end is welded to an inner surface of the yoke. Because the insert is forged from the same material as the yoke, a continuous welding procedure can be employed that can be performed robotically. The insert provides a simple yet effective means of connecting the hydraulic cylinder while adding stiffness to a necked-down portion of the transition portion. An interference fit between the insert and the transition also resists fatigue caused by cyclical loading.

[0010]Plates form the remainder of the transition portion. Lugs for connecting to a dipper, which are manufactured as forgings rather than castings, are welded to the plates. The lugs experience significant stress and providing superior mechanical properties of forgings translates into increased fatigue life of the handle assembly, which minimizes costly crack repair castings require.

Problems solved by technology

Those of ordinary skill in the art will appreciate yoke transition portions are traditionally cast because they possess areas of varying thicknesses and of complex shapes, which makes the component difficult to forge.

Further, the above-described embodiments, aspects, objectives, and configurations are neither complete nor exhaustive.

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