Secure Mounting of Excavation Equipment Teeth

Abstract

A replaceable wear point of excavating equipment, such as a tooth of an excavator bucket, is mounted on the bucket's nose piece using a conventional fastener arrangement plus an adhesive, preferably epoxy, injected into the tooth pocket to fill a gap between the nose piece and the tooth pocket. For injecting the epoxy, a hole is preferably formed through the tooth to communicate into the bottom of the tooth pocket. The injected epoxy preferably squeezes out of the tooth pocket opening and is smoothed to form an epoxy fillet along the junction of the tooth and the nose piece. The epoxy fills gaps, holds the tooth tight against wiggling on the nose piece, and seals out grit and water, to prevent or reduce interior wear of the tooth pocket and the nose piece, and to prevent or delay the tooth from falling off the nose piece.

Description

FIELD OF THE INVENTION[0001]The present invention relates to a method, an arrangement and a combination of components for securely mounting replaceable ground-engaging wear points, called teeth herein, of ground-engaging tools of excavating equipment.[0002]BACKGROUND INFORMATION[0003]Excavating equipment is used in various industries, such as mining, quarrying, dredging, road building, landscaping, commercial and residential building construction, and various other construction industries, for digging holes, trenches, tunnels, etc., for breaking-up, loosening and removing soil, gravel, rocks, ore, coal and other ground materials, and for loading such materials into further earth moving equipment. Such excavating equipment includes hydraulic excavators, backhoes, bucket loaders, skid-steer loaders, bucket and rotary dredgers, earth boring drills, excavation drag lines, cable shovels, face shovels, clam shell buckets, ground rippers and the like. All of such equipment includes a groun...

AI Technical Summary

Benefits of technology

The invention provides a method, arrangement, and components for securely mounting a replaceable ground-engaging wear point or tooth on a powered ground-engaging tool such as a bucket of excavating equipment. The method involves filling the existing gaps between the nose piece and the interior of the tooth pocket with an adhesive, such as a thermosetting epoxy adhesive, to prevent the penetration of grit particles and water. The epoxy hardens and adhesively bonds the tooth onto the nose piece, in addition to the mechanical connection provided by the tooth fastening arrangement. The method is easy to perform in the field, requires minimal downtime of the excavating equipment, and can be used to refurbish loose worn teeth. The invention also provides an improved method for injecting epoxy into the tooth pocket to securely mount the tooth and prevent wiggling or looseness of the tooth.

Problems solved by technology

These teeth are subject to extreme wear, due to digging, scraping and prying in soil, gravel, rocks, broken concrete, and other coarse, abrasive, hard materials.

While these fastener arrangements are intended to hold the tooth on the nose piece and transfer digging forces from the tooth into the nose piece (in addition to the force-transferring contact of the nose piece in the tooth pocket), there are always remaining gaps between the tooth and the nose piece in the tooth pocket, and the tooth is always slightly loose on the nose piece.

This is true especially after the tooth has been in use for digging, resulting in wear and looseness of the tooth.

However, whenever the tooth can wiggle or move back and forth on the nose piece, this causes chafing wear of both the nose piece and the interior surfaces of the tooth pocket.

As a result, the fit of the tooth becomes ever looser on the nose piece, which causes the wear to progress even more rapidly.

Furthermore, when the teeth and bucket (or other ground-engaging tool) are digging in sand, soil or gravel, small abrasive particles of the ground material easily enter the gaps between the tooth and the nose piece in the tooth pocket, and these particles further abrasively accelerate the wear of the nose piece and the tooth pocket.

The interior wear becomes especially significant when digging in loose sandy or gritty soil, because the sand or grit gets into the gaps between the nose piece and the interior of the tooth pocket and causes significant interior wear, while the exterior wear of the tooth is less in such soil than in hard rocky gravel or broken rock.

Still further, water penetrates into the gaps between the nose piece and the tooth in the tooth pocket, and causes rapid rusting corrosion of the worn metal of the nose piece and the tooth in the pocket.

Finally, the tooth can become so loose that the fastener arrangement can no longer hold it, for example because the elastic or resilient range of the keeper device does not extend as far as the wear has progressed, so that the keeper loses its resilient keeping function.

The fastener pin then falls out and the tooth falls off the nose piece during a digging operation, whereby the tooth is generally lost in the soil or other ground material.

During each week of full time digging operation, an excavation contractor operating several excavation machines may need to replace several teeth that have been lost or that have excessive interior wear and looseness, so that the costs of replacing lost or worn teeth can become substantial.

This is especially problematic when a tooth has become loose and / or has fallen off the nose piece even though the exterior dimensions and configuration of the tooth are still within a serviceable range.

Furthermore, if the nose piece becomes significantly worn, then the nose piece itself should also be replaced, which involves a significant replacement part cost and also significant labor costs.

The nose piece especially becomes rapidly worn if digging continues after a tooth is lost.

But many teeth that have only about 50% exterior wear are now typically being discarded and replaced with new teeth, simply because of looseness of the tooth on the nose piece due to the interior wear of those parts.

If operated further, such loose teeth often fall off anyway if they are not replaced.

For example, it has been observed that teeth fall off and are lost after as little as about 400 hours of operation, due to interior wear and looseness of the tooth on the nose piece.

For the above reasons, excavation contractors and other excavation equipment operators are suffering significant additional costs in replacing teeth that have been lost due to falling off, or that have become too loose on the nose piece due to interior wear, even though the exterior of the tooth would still have provided additional service life.

Those approaches, however, do not resolve or even address the above mentioned problems of interior tooth pocket and nose piece wear, looseness of the tooth and penetration by grit and water.

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