GEOMETRIC PROFILE FOR IMPROVED MANUFACTURABILITY OF A GROUND ENGAGING TOOL

A wear member includes a first leg, a second leg, and a throat portion connecting the first leg to the second leg. The first leg defines a first leg thickness, and the throat portion defines a throat portion thickness disposed adjacent to the first leg thickness. A ratio of the throat portion thickness to the first leg thickness ranges from 1.1 to 1.2.

TECHNICAL FIELD

The present disclosure relates generally to the manufacturing process for producing a ground engaging tool. More specifically, the present disclosure relates to an improved geometric profile that enhances the manufacturability of a ground engaging tool.

BACKGROUND

Ground engaging tools, edge protectors, and shrouds, etc. (collectively may be referred to as wear members) are routinely used by machines in the earthmoving, mining, agricultural, and construction industries, etc. These components are typically manufactured from iron using a casting process as depicted inFIG.1. More specifically, shrouds50are shown inFIG.1that are produced using side risers (also referred to as feeders since they provide material to the cavity in order to compensate for shrinkage). The use of side risers limits the number of cavities in the mold, reducing the productivity of the manufacturing process.

FIG.2depicts what happens if the side risers are eliminated in an attempt to increase the productivity of the manufacturing process. Particularly, the risk for porosity is increased to an undesirable level, producing a shroud that may crack in use, etc. Also, the current manufacturing process only has about a 50% yield rate, a 28% rework rate, and a 22% scrap due in part to the use of the side risers.

U.S. Pat. No. 10,294,638B2 discloses a shroud that is configured to be attached to a work implement. The shroud may comprise a body defining a closed end, an open end, a first side surface and a second side surface. The first side surface and the second side surface span from the closed end to the open end. A working portion is disposed proximate the closed end, a first leg extends rearward from the working portion to the open end, and a second leg extends rearward from the working portion to the open end. The side surfaces also form the side surfaces of the legs. A throat portion connects the legs and working portion together. The first and second legs define a slot, the slot defining a direction of assembly onto a work implement and the body defines a Cartesian coordinate system wherein the X-axis is parallel with the direction of assembly. The working portion defines a ground engaging surface at the closed end that may comprise a convex arcuate portion intersecting with the X-axis, a first concave arcuate portion extending from the convex arcuate portion toward the first side surface, and a second concave arcuate portion extending from the convex arcuate portion toward the second side surface when the ground engaging surface is projected onto a X-Y plane along the Z-axis.

However, the ‘638 patent does not address the manufacturing process for making the shroud. Accordingly, a manufacturing process that increases productivity and yield rate is needed.

SUMMARY OF THE DISCLOSURE

A wear member that is configured to be attached to a work implement according to an embodiment of the present disclosure may comprise a first leg, a second leg, and a throat portion connecting the first leg to the second leg. The first leg may define a first leg thickness, and the throat portion may define a throat portion thickness disposed adjacent to the first leg thickness. A ratio of the throat portion thickness to the first leg thickness may range from 1.1 to 1.2.

A shroud that is configured to be attached to an edge of a work implement according to an embodiment of the present disclosure may comprise a top leg with a rear surface having a rear gate blemish, a bottom leg with a bottom surface having a bottom gate blemish, and a throat portion including a first beveled portion extending from the top leg, and a second beveled portion extending from the first beveled portion to the bottom leg. The top leg may define a first top leg thickness, and the first beveled portion may define a first beveled portion thickness that is greater than the top leg thickness.

A mold for casting a shroud according to an embodiment of the present disclosure may comprise a plurality of cavities, a sprue, and a feeder system connecting the sprue to the plurality of cavities. The feeder system includes a plurality of rear gates that are in fluid communication with the plurality of cavities, and the sprue.

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments of the disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. In some cases, a reference number will be indicated in this specification and the drawings will show the reference number followed by a letter for example, 100a, 100b or a prime indicator such as 100′, 100″ etc. It is to be understood that the use of letters or primes immediately after a reference number indicates that these features are similarly shaped and have similar function as is often the case when geometry is mirrored about a plane of symmetry. For ease of explanation in this specification, letters or primes will often not be included herein but may be shown in the drawings to indicate duplications of features discussed within this written specification.

Various embodiments of a wear member or a shroud are disclosed that may improve the manufacturing process and increase the yield rate without adversely affecting the strength of the wear member or the shroud. More specifically, the profile geometry of the wear member or the shroud may allow such an improvement in the manufacturing process.

FIG.3shows a machine100in the form of an excavator employing a bucket102to move dirt, rocks, etc. and that is propelled by a track system104and powered by an engine . A cab106is also provided to house an operator (not shown) for controlling the movement of the bucket via a stick and boom system108. The bucket and machine may take different forms in various embodiments of the present disclosure as explained in the following paragraph.

FIGS.4and5show that shrouds200, tips110, and adapters112may be attached to the front lip114of the bucket. The shrouds, tips, and adapters, etc. may be more generally characterized as “wear members” herein. It is also to be understood that other work implements other than buckets may employ wear members configured according to various embodiments of the present disclosure including shears, grapples, rippers, etc.

Looking now atFIGS.5and6, such wear members (e.g., shroud200) may comprise a first leg202, a second leg204, and a throat portion206that connects the first leg202to the second leg204. The first leg202may define a first leg thickness T202, while the throat portion206may define a throat portion thickness T206 disposed immediately adjacent to the first leg thickness T202 (e.g. closer to the first leg than the second leg). A ratio of the throat portion thickness T206 to the first leg thickness T202 may range from 1.1 to 1.2 in some embodiments of the present disclosure. This slightly increased thickness in the throat portion may alleviate flow hesitation during the casting process, allowing a rear gate302to be employed in the mold300(see alsoFIG.8) without increasing the risk of voids forming in the throat portion.

Consequently as depicted inFIGS.6and7, the first leg202may define a rear surface208with a rear gate blemish210. The first leg202may take the form of a top leg that is longer than the second leg204, which may take the form of a bottom leg that is shorter than the top leg. This may not be the case in other embodiments of the present disclosure. The second leg204may have a bottom surface212with a bottom gate blemish214that results from the top risers304shown inFIG.8.

Again, the wear member may be a shroud200, but not necessarily so. As best seen inFIG.6, the first leg202, the second leg204, and the throat portion206may define a first lateral side216, and a second lateral side218. The throat portion206may include a rib220that is spaced away from the first lateral side216, and the second lateral side218, forming a first notch222, and a second notch224. As best seen inFIG.7, the rib220at least partially defines the throat portion thickness T206. In other embodiments, the rib or added material extends completely to both lateral sides such that no notches are present, etc.

Referring toFIGS.6and7, an embodiment of a shroud may be more specifically described as comprising a top leg (e.g., see first leg202) with a rear surface208having a rear gate blemish210, and a bottom leg (e.g. see second leg204) with a bottom surface212having a bottom gate blemish.214The throat portion206may include a first beveled portion226that extends from the top leg, as well as a second beveled portion228that extends from the first beveled portion226at an oblique angle230(seeFIG.7) to the bottom leg. The top leg defines a first top leg thickness (e.g., see T202), and the first beveled portion defines a first beveled portion thickness (see throat portion thickness T206) that is greater than the top leg thickness. Moreover, the second beveled portion defines a second beveled portion thickness T228 that is greater than the first beveled portion thickness. As shown, the top leg thickness and the first beveled portion thickness are substantially constant, while the second beveled portion thickness varies. This may not be the case for other embodiments of the present disclosure.

As alluded to earlier herein with reference toFIG.6, the throat portion may define a first lateral surface, and a second lateral surface that may lack gate blemishes since the side gates may be eliminated. A protrusion (e.g., see rib220)may be spaced laterally away from the first lateral surface, and the second lateral surface, forming a first side recess (e.g., see first notch222) and a second side recess (e.g., see second notch224). As best understood with reference toFIG.7, the protrusion at least partially defines the first beveled portion thickness (e.g., see T206), and the second beveled portion thickness (e.g., see T228). This may not be the case for other embodiments of the present disclosure.

As best seen inFIG.6, the top leg defines at least a first retaining mechanism receiving aperture232. Also, a lifting eye234extends from the first beveled portion to the top leg. Other positions are possible or the lifting eye, and these features may be omitted in other embodiments of the present disclosure, etc.

The shroud that is shown is a center shroud as evidenced by its symmetry about its lateral midplane (or cross-sectioned plane ofFIG.7). However, the inventor has also simulated that the shroud could also be a left shroud or a right shroud that are asymmetrical about the lateral midplane (similar to what is shown inFIGS.19and21of U.S. Pat. No. 10,724,212B2, orFIGS.1,4and5of the present application).

Still referring toFIG.6, the protrusion defines a protrusion lateral width W220, and the throat portion defines a throat portion lateral width W206. A ratio of the protrusion lateral width to the throat portion lateral width may range from 0.5 to 0.9 in some embodiments of the present disclosure. Likewise, the rear gate blemish may define a rear gate blemish lateral width W210, and a ratio of the rear gate blemish lateral width to the throat portion lateral width W206 may be greater than 0.25. In some embodiments, this ratio may be greater than 0.35 (e.g., may be approximately 0.4 in some embodiments).

The configuration, ratios and dimensional ranges of any of the features of any of the embodiments discussed herein may be altered to be different than what has been explicitly discussed or shown depending on the application.

INDUSTRIAL APPLICABILITY

In practice, a wear member, or a shroud according to any embodiment described herein may be provided, sold, manufactured, and bought etc. as needed or desired in an aftermarket or OEM (original equipment manufacturer) context. For example, a wear member or a shroud may be used to retrofit a work implement already in the field or may be sold with a piece of equipment (e.g., a machine such as an excavator, a wheel loader, etc.) using that work implement at the first point of sale of the piece of equipment.

The wear member or shroud may be fabricated from iron, cast-iron, steel, or gray-cast iron or other suitable material that is durable, and that can be used in the casting process. The geometry of the wear member or shroud may be formed during the casting, and then may be rough machined and/or finish machined if necessary. Suitable machining processes may include milling, turning, electrical discharge machining, etc. The wear member may be separated from the top risers and the rear gates, forming a gate blemish that may be proud, recessed, or some combination of proud and recessed relative to the exterior surface of the wear member or shroud. The gate blemish may be removed by machining, etc.

FIGS.8and9show that the change in thickness of the throat portion allows the side gates to be eliminated and a single rear gate to be employed, allowing for more cavities, increasing the yield rate without increasing the risk for porosity.

More specificallyFIG.8illustrates a mold300for casting a shroud (or other wear member). The mold300may comprise a plurality of cavities306, a sprue308, and a feeder system310(may also be referred to as a spider or runner system) connecting the sprue to the plurality of cavities. A plurality of rear gates302that are in fluid communication with the plurality of cavities, and the sprue as well as top risers304are also shown.

In some embodiments, each of the plurality of cavities is connected to the feeder system by a single rear gate of the plurality of rear gates, and each of the plurality of cavities is in fluid communication with a top riser. This may not be the case for other embodiments of the present disclosure.

It is to be understood that the mold would actually be the negative image of the cast components (may also be referred to as a “shot”) shown inFIG.8.

It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments of the apparatus and methods of assembly as discussed herein without departing from the scope or spirit of the invention(s). Other embodiments of this disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the various embodiments disclosed herein. For example, some of the equipment may be constructed and function differently than what has been described herein and certain steps of any method may be omitted, performed in an order that is different than what has been specifically mentioned or in some cases performed simultaneously or in sub-steps. Furthermore, variations or modifications to certain aspects or features of various embodiments may be made to create further embodiments and features and aspects of various embodiments may be added to or substituted for other features or aspects of other embodiments in order to provide still further embodiments.