Patent Application
20170356166
This patent disclosure relates generally to ground-engaging tools and, more particularly to retaining systems for removably attaching the ground-engaging tools to various earth-working machines.
Earth-working machines, such as, for example, excavators, wheel loaders, hydraulic mining shovels, cable shovels, bulldozers, and draglines, are generally used for digging or ripping into the earth or rock and/or moving loosened work material from one place to another at a worksite. These earth-working machines include various earth-working implements, such as a bucket or a blade, for excavating, scooping, and moving the earthen work material. These implements may be subjected to extreme wear and/or damage from the impacts and abrasion experienced during the earth-working applications.
To facilitate penetration and removal of earthen materials, the earth-working implements may be equipped with ground-engaging tools such as teeth, edge protectors, and other cutting tools that are arranged where the ground-engaging tools will encounter the most damaging impacts and abrasion. Because the ground-engaging tools themselves are subject to wear and damage, they may be designed to be removable and replaceable with new tools as part of the maintenance of the earth-working implement. To enable removal and replacement of the ground-engaging tools, the tools typically include or may be designed with retainer systems that attach the tools to the earth-working implements.
For example, one type of retainer system is described in U.S. Pat. No. 9,074,350 (“the '350 patent”) assigned to the applicant of the present disclosure. The '350 patent describes a ground-engaging tool assembly in which a supporting adapter is permanently attached to the earth-working implement and a wear member, such as a ground-engaging tip, is releasably secured to the adapter via a locking mechanism. In particular, the ground-engaging tip has a cavity disposed therein that receives a correspondingly shaped portion of the adapter. When the adapter slides into the cavity, a lug post projecting from a lateral surface of the adapter can align and mate with a notch formed in the sidewall of the cavity. Assembled into the notch may be a rotatable collar-like retainer having a semi-circular latch collar and that can be accessed through an aperture or opening disposed in the cavity sidewall. To lock the adapter and ground-engaging tip together, the retainer can be turned using a ratchet tool or Allen wrench inserted through the aperture so the collar slides around the lug post thereby preventing the adapter from backing out of the cavity disposed in the ground-engaging tip. To release the components, the retainer can be turned back to its unlocked position freeing the lug post. Like the '350 patent, the present disclosure is directed to a releasable retainer system for attaching a ground-engaging tool to an earth-working implement.
The disclosure describes, in one aspect, a ground-engaging tool system including an adapter with an attachment structure for attachment to a work implement and a ground-engaging tip releasably connectable to the adapter. The adapter includes a support nose extends forward from the attachment structure and that has at least a first adapter surface with at least a first lug post projecting there from. The lug post is generally shaped as a frustum with an exterior side surface delineated by at least a smaller first radius and a larger second radius. To mate with the adapter, the ground-engaging tip includes a cavity disposed therein configured for receiving the support nose. A retainer is configured to be rotatably accommodated within a notch located inside the cavity. The retainer further includes a latch collar having a curved interior surface delineated by a latch collar radius that is generally equal in dimension to the second radius. The retainer can rotate around the lug post so that the curved interior surface and exterior side surface contact each other.
In another aspect, the disclosure describes a lug post projecting from an adapter and configured to latch and unlatch with a rotatable retainer having a curved interior surface on a ground-engaging tool. The lug post is shaped as a frustum and includes a base on the adapter and a truncated flat above the base. An exterior side surface extends between the base and the truncated flat and further forms a peripheral edge with the truncated flat. The peripheral edge has a first arc with a first center and a second arc with a second center, wherein the first and second centers are not coincident in location on the truncated flat.
In yet another aspect, the disclosure describes an adapter for a ground-engaging tool designed for releasable connection with a ground-engaging tip. The adapter includes an attachment structure configured to attach to a work implement and a support nose extending from the attachment structure. The support nose has a first adapter surface and a first lug post projecting from the first adapter surface. The lug post is generally shaped as a frustum with an exterior side surface and a truncated flat intersecting at a peripheral edge. The peripheral edge is delineated in part by at least a first radius originating from a first center on the truncated flat and a second radius originating from a second edge on the truncated flat, wherein the first center and the second center are not coincident in location on the truncated flat.
Now referring to the drawings, wherein like reference numbers refer to like elements, there is illustrated in
Referring to
To secure the adapter 112 to the base edge of the bucket or other work implement, the adapter has an attachment structure 120 with a first mounting leg 122 and a second mounting leg 124 projecting rearward with respect to the remainder of the adapter. The first and second mounting legs 122, 124 are arranged in a spaced apart or bifurcated manner so the legs define a recess 126 between them that can receive the base edge of the implement. With the first and second mounting legs 122, 124 positioned on opposite sides of the base edge received in the recess 126, the legs can be secured to the implement using any suitable method to hold the adapter 112 in place. For example, fasteners such a threaded bolts or rivets can used to fasten the first and second mounting legs 122, 124 to the base edge while in other embodiments, the first and second mounting legs may be welded to the edge. Hence, compared to the ground-engaging tip 114, the adapter 112 is relatively permanently secured on the work implement, although the disclosure contemplates that occasionally, though less frequently, the adapter itself may need to be removed and replaced. Additionally, in other embodiments, alternative attachment structures may be utilized such as structures comprising a single leg, inserts or sockets, or any other suitable attachment configuration known in the art.
To attach to the ground-engaging tip 114, the adapter 112 can include a block-like support nose 130 that extends forward of the attachment structure 120 and that may be shaped to mate with a corresponding feature on the tip. The shape of the support nose 130 can be provided by a plurality of adapter surfaces arranged to form the block-like structure. For example, in illustrated embodiment, the support nose 130 may have a tapered shape provided by a first inclined adapter surface 132 and a second inclined adapter surface 134 located below and opposite of the first inclined adapter surface, with the inclined adapter surfaces arranged at a sloping or converging angle with respect to each other and unite together at a blunted or rounded edge 135. The remainder of the block-like shape of the support nose 130 may be further delineated by a first lateral adapter side 136 and an oppositely located second lateral adapter side 138 that extend between the converging first and second inclined adapter surfaces 132, 134. In other embodiments, however, the support nose 130 can include any other suitable arrangement of adapter surfaces to provide a three dimensional structure. The adapter 112 may be made from any material suitable for the intended environment such as, for example, cast or machined steel or other metals.
To enable the ground-engaging tip 114 to penetrate material, the tip may also have a wedge-like or tapered shape provided by a first inclined tip surface 140 and a corresponding second inclined tip surface 142 arranged at a converging angle with respect to each other. The first and second inclined tip surfaces 140, 142 may intersect at a relatively sharp penetration edge 144 to complete the tooth-like appearance of the ground-engaging tip 114. The ground-engaging tip 114 may further include a first lateral tip side 146 and a spaced-apart second lateral tip side 148 that extend between and conform to the converging arrangement of the first and second inclined tip surfaces 140, 142. However, in other embodiments, the ground-engaging tip 114 may be configured in different shapes to perform different tasks associated with the work-implement.
Referring to
To enable the releasable mating of the adapter 112 and the ground engaging tip 114, the two components can be provided with or form together a retainer system 160 that allows the parts to be selectively locked and unlocked together. In a particular embodiment, the retainer system 160 may be configured to releasably engage with corresponding structures formed on the support nose 130, which may be in the form of one or more lug posts that project from the surface of the support nose. For example, a first lug post 162 may project normally from the first lateral adapter side 136 while a second lug post 164 projects in the opposite direction from the second lateral adapter side 138; however, in other embodiments, the lug posts may be present in different numbers and at different locations on the adapter 112. As described more fully below, the lug posts 162, 164 may have various configurations but are generally overall cylindrical or frustum-like in shape. The first and second lug posts 162, 164 can be integrally cast as part of the adapter 112 or may be made as separate items that are connected to the support nose 130 by, for example, threaded posts or the like.
To accommodate the components of the retainer system 160 that engage the lug posts 162, 164, the ground-engaging tip 114 can have corresponding notches formed into the interior walls and exposed to the cavity 150. In the illustrated embodiment, the notches can include a first notch 170 disposed into the interior surface of the first lateral tip side 146 and a second notch 172 disposed in the interior surface of the oppositely arranged second lateral tip side 148. The first and second notches 170, 172 may be formed as depressions into the sides and may each define a generally curved interior surface 174. Moreover, the first and second notches 170, 172 are accessible from the rear of the ground engaging tip 114 proximate the opening of the cavity 150. Hence, when the support nose 130 is inserted into the cavity 150, the first and second lug posts 162, 164 can align with and be received into the respective first and second notches 170, 172. Moreover, the larger dimensioned first and second notches 170, 172 may connect with respective, smaller sized first and second lock apertures 176, 178 which are disposed through the corresponding first and second lateral tip sides 146, 148 such that the cavity 150 is accessible from the exterior of the ground-engagement tip 114.
To lock the first and second lug posts 162, 164 into the respective first and second notches 170, 172, the retainer system 160 can include a first retainer 180 and a second retainer 182. The first and second retainers 180, 182 are configured to seat within the respective first and second notches 170, 172 in a manner that enables the retainers to rotate about the respective lug posts. Referring to
To cause the retainers 180, 182 to rotate with respect to the retainer axis line 188, the circular cap 184 can include a tool engagement socket 194 formed on the side opposite the latch collar 186 that can receive or engage a tool such as an Allen wrench or socket driver. Referring back to
Referring still to
Referring to
In an embodiment, to cause the lug posts 162, 164 to assume a more oblong or elliptical shape, the radial center of specific portions of the truncated flat 204 may be shifted or offset along the reference diameter 219. For example, the peripheral edge 206 of the truncated flat 204 of may include a first arc 220 that has a first radius 222 equal in dimension to the reference radius 212 (i.e., Rref.=R1st) but which originates from a first center 224 that is eccentrically offset or shifted from the reference center 214 (i.e., Cref.≠C1st). Hence, the reference center 214 and the first center 224 may assume different positions along the reference diameter 219. When viewed in plan, the first arc 220 is therefore offset with respect to or sits within the reference circle 210. Likewise, the first arc 220 may have a middle point or first midpoint 226 that is aligned on the reference diameter 219 but that is offset from the first reference point 216 where the reference diameter intersects the reference circle 210. Further, the first arc 220 may extend or sweep in either direction of the first midpoint 226 for about 70° to 80° degrees. Hence, the first arc 220 may correspond to about 140° to about 160° of the peripheral edge 206 of the truncated flat 204.
The peripheral edge 206 of the truncated flat 204 can also include a second arc 230 that can be positioned diametrically opposite to the first arc 220 with respect to the reference diameter 219. The second arc 230 may be characterized by a second radius 232 that originates from a second center 234. To further vary the frustoconical shape, the second center 234 may be eccentrically shifted or offset with respect to both the reference center 214 of the reference circle 210 (i.e., C2nd≠Cref) and the first center 224 of the first arc 220 (C2nd≠C1st); hence, the reference center and the first and second centers are not coincident with each other. In accordance with this embodiment, the second center 234 may be located along the portion of the reference diameter 219 that extends from the reference center 214 in the opposite direction of the location of the first center 224. Hence, the first center 224 may be located closer to the second arc 230 while the second center 234 may be located closer to the first arc 220.
In addition, the dimension of the second radius 232 may be different from the dimension of the reference radius 212 (R1st>Rref.) and the first radius 222 (R1st>R2nd); for example, the second radius may be dimensionally greater than the equally sized reference radius and first radius. Hence, although the second center 234 is positioned further from the second reference point 218 than the reference center 214, the second arc 230 generated by the second radius 232 passes through the second reference point 218 due to the difference in radial dimensions. In other words, the reference circle 210 and the second arc 230 generated by second radius 232 overlap or are at least tangential proximate the second reference point 218. The second arc 230 may also include a second midpoint 238, which corresponds in position with the second reference point 218, and the second arc may extend or sweep in either angular direction approximately 45° to 55°. Hence, the second arc 230 may correspond to about 70° to about 90° of the peripheral edge 206 of the truncated flat 204.
A result of the foregoing arrangement is that only portions of the peripheral edge 206 of the truncated flat 204 overlap the circumference of the reference circle 210 while others do not. Another result is the dimensional length of the second arc 230 is larger than the dimensional length of the first arc 220 and of the reference circle 210 for a given angle or angular sweep. In other words, because the second radius 232 is larger than the first radius 222, the length of the second arc 230 covered by a 60° sweep of the second radius will be larger than the length of the first arc 220 covered by the same 60° sweep of the first radius. In effect, having a portion of the peripheral edge 206 and the exterior surface 200 associated with it correspond to the second arc 230 and second radius 232 increases the surface area of the lug posts 162, 164 in that region. As described below, this is beneficial when the lug posts engage with the retainers.
To transition the peripheral edge 206 between the first arc 220 and the second arc 230, the lug posts 162, 164 may be formed with a first beveled flat 240 and a second beveled flat 242 that generally follows with the tapered angle of the exterior surface 200 between the peripheral edge 206 and the base 202. The first and second beveled flats 240, 242 cause the peripheral edge 206 of the truncated flat 204 to assume the appearance of a straight line 244 in the transition regions. In an embodiment, an end point of the vertical line 244, and thus the location of the first and second beveled flats 240, 242, can be determined by drawing a reference line 246 from the first center 224 at an approximately 90° angle with respect to reference diameter 219, i.e. vertically downwards in
Referring to
It may be appreciated that a possible advantage of placing the exterior surface 200 of the lug posts 162, 164 in contact with the curved interior surface 190 of the retainers 180, 182 along the arc of contact 250, as opposed to a tangential point, is that a significant amount of friction may be created between the components. That friction may resist relative rotation between the retainers 180, 182 and the lug posts 162, 164, thereby assisting in holding the retainers 180, 182 in the locked position and prevent them from unintentionally rotating to the unlocked position. Another possible advantage is that curved interior surface 190 and the exterior side surface 200 may initially conform in shape along the arc of contact 250 when, for example, new ground-engaging tips are installed. Hence, there is less wear and abrasion than would occur if contact between the retainers 180, 182 and lugs posts 162, 164 occurred at a single point of contact. In such instances, the single point of contact is required to wear down to better distribute the abutting forces between the retainers 180, 182 and lugs posts 162, 164, a process referred to as “seating.” In other words, the lugs posts 162, 164 in accordance with the disclosure are pre-seated with the retainers 180, 182.
To unlock the components, the operator may begin rotating the retainers 180, 182 with respect to the lug posts 162, 164 in the counterclockwise direction as illustrated in
As shown in
When the retainers 180, 182 have been rotated 180° from the locked position shown in
It will be appreciated that the foregoing description provides examples of the disclosed system and technique. However, it is contemplated that other implementations of the disclosure may differ in detail from the foregoing examples. All references to the disclosure or examples thereof are intended to reference the particular example being discussed at that point and are not intended to imply any limitation as to the scope of the disclosure more generally. All language of distinction and disparagement with respect to certain features is intended to indicate a lack of preference for those features, but not to exclude such from the scope of the disclosure entirely unless otherwise indicated.
Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context.
The use of the terms “a” and “an” and “the” and “at least one” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The use of the term “at least one” followed by a list of one or more items (for example, “at least one of A and B”) is to be construed to mean one item selected from the listed items (A or B) or any combination of two or more of the listed items (A and B), unless otherwise indicated herein or clearly contradicted by context.
Accordingly, this disclosure includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the disclosure unless otherwise indicated herein or otherwise clearly contradicted by context.
