FIELD OF THE INVENTIONThe present invention pertains to a wear assembly for the digging edge of excavating equipment, and in particular, to an adapter which is mechanically attached to such excavating equipment.
BACKGROUND OF THE INVENTIONExcavating teeth and other wear members have long been mounted along the digging edge of buckets and other excavating equipment to break up the ground and enhance the digging operation. As can be appreciated, the wear members used along the digging edge are often placed in harsh working conditions and are thus subjected to a high degree of wearing.
In order to minimize the size of the part needing frequent replacement, excavating teeth are ordinarily formed as a plurality of integrally connected parts. An excavating tooth usually comprises an adapter, a point, and a lock pin for securing the point to the adapter. The adapter has a rear mounting end which is configured for attachment to the digging edge of an excavator and a forwardly projecting nose for mounting the point. The point is a tapered member provided with a forward earth-penetrating end and a rearwardly opening socket adapted to be received over the adapter nose. Although the points wear out more frequently, the adapters are also subjected to wearing and periodic replacement. As can be appreciated, the adapters must not only be capable of being firmly secured to the excavator to prevent undesired loss of the tooth during use, but it is desirable that they also be capable of being readily removed and installed by operators in the field.
A number of different approaches have been developed for securing wear members, such as adapters, to the digging edge of a bucket. U.S. Pat. No. 4,577,423 to Hahn provides an example of an adapter that is welded to the lip of a bucket. As to be expected, welding functions to securely attach the adapter to the bucket. However, the replacement of welded adapters is typically performed at a shop rather than in the field. The time and difficulty required to remove and install such welded adapters has proven to be a significant deterrent.
U.S. Pat. No. 4,267,653 to Hahn et al. describes an example of a mechanically attached adapter. As shown in this patent, mechanically attached adapters are frequently held to a bucket by the combination of a C-shaped clamp and a wedge. The wedge must be fit very tightly between the clamp and the adapter in order to securely hold the adapter to the bucket. Typically, the wedge is inserted into the assembly by repeated blows with a heavy sledge hammer. As can be appreciated, this is an onerous and time-consuming task for field workers, especially to achieve the final inch of movement needed to mount the assembly. Further, the wedge even when tightly inserted often becomes loose under heavy loading, which thus risks loss of the tooth. Finally, these assemblies require a hole to be formed in the bucket lip, which reduces the lip's strength and integrity.
U.S. Pat. No. 5,088,214 to Jones discloses another arrangement for mechanically attaching a wear member to the lip of a bucket. According to this construction, the wear member is matingly slipped over a T-shaped boss that has been welded to the bucket lip. A rigid locking block is fit within an opening defined in the top of the wear member to prevent undesired removal of the wear member from the lip. While this construction avoids the formation of a hole in the bucket lip, it is not suitable for use in attaching all types of wear members to any kind of bucket. For instance, larger buckets provided with beveled lips tend to generate large forces on an adapter which could in some circumstances cause instability in the mounting assembly. Further, the assembly lacks means for eliminating looseness that may exist between the wear member and the boss.
SUMMARY OF THE INVENTIONThe wear assembly of the present invention enables the wear member to be securely attached to the digging edge of an excavator without the need for welding of the wear member or, in the preferred construction, forming a hole in the excavator's edge. Moreover, the assembly has sufficient stability to amply support adapters on a bucket lip formed with a beveled ramp. Nevertheless, despite the durability of the wear assembly, the wear members can still be easily removed or installed when replacement of the member becomes necessary.
In accordance with one aspect of the invention, a wear assembly includes a wear member which releasably attaches to a boss that is fixed to an excavator. The wear member includes a leg which extends rearwardly over the front edge of the excavator. A T-shaped structure is formed along the inner side of the leg for attachment to the boss. The complementary T-shaped coupling structures of the wear member and the boss prevent dislodgement of the wear member under load. The wear member also has front and rear bearing surfaces for resisting the applied loads during use.
In another aspect of the present invention, the boss is formed with a first surface which lies against the excavator and a second surface which forms a T-shaped coupling structure for receiving a wear member. The boss further includes a front bearing face for bracing the wear member and a rear bearing face for abutting a lock member to prevent removal of the wear member. In the preferred construction, a clamp section is formed along the first surface to wrap about the front digging edge of the excavator.
In accordance with another aspect of the invention, an opening for receiving a lock is formed through the leg of the wear member. The opening has a generally T-shaped configuration with a stem portion and a cross portion. The stem portion extends longitudinally from the rear end of the leg to the lateral cross portion of the opening. The body of the lock sets between the rear end of the boss and the rear wall of the cross portion in order to prevent removal of the wear member from the boss. An adjustment assembly extends through the body to eliminate any looseness which may exist between the wear member and the boss.
In accordance with another aspect of the invention, a deflector can be fixed to the excavator at a position behind the wear member. The removal of a wear member from the boss can frequently be a difficult task due to the compaction of fines around the parts. However, a lock member with an adjustment assembly can be easily used with a deflector to slide the wear member forwardly from the boss.
BRIEF DESCRIPTION OF THE INVENTIONFIG. 1 is top plan view of a wear assembly in accordance with the present invention.
FIG. 2 is a side elevational view of the wear assembly.
FIG. 3 is a cross-sectional view taken along line3-3 inFIG. 2.
FIG. 4 is a perspective view of a boss in accordance with the present invention.
FIG. 5 is a top plan view of the boss.
FIG. 6 is a side elevational view of the boss.
FIG. 7 is a cross-sectional view of the boss taken along line7-7 inFIG. 6.
FIG. 8 is an rear elevational view of the boss.
FIG. 9 is a top plan view of an adapter in accordance with the present invention.
FIG. 10 is a side elevational view of the adapter.
FIG. 11 is a cross-sectional view of the adapter taken along line11-11 inFIG. 10.
FIG. 12 is a rear elevational view of the adapter.
FIG. 13 is a top plan view of an alternative adapter in accordance with the present invention.
FIG. 14 is a top plan view of a lock member in accordance with the present invention.
FIG. 15 is a side elevational view of the lock member.
FIG. 16 is a rear elevational view of the lock member.
FIG. 17 is a sectional view of an alternative lock member in accordance with the present invention.
FIG. 18 is a rear elevational view of the lock member partially inserted into an adapter assembly in accordance with the present invention.
FIG. 19 is a top plan view of another alternative adapter in accordance with the present invention.
FIG. 20 is a side elevational view of the other alternative adapter on the digging edge of an excavator.
FIG. 21 is a top plan view of a wear assembly in accordance with the present invention with the lock member positioned for effecting removal of the wear member.
DETAILED DESCRIPTION OF THE INVENTIONThe present invention pertains to a wear member, such as an adapter, which is mechanically attached to the digging edge of an excavator. While wear members in accordance with the present invention can be secured to a number of different excavators, the present application for illustration purposes discusses only the use of adapters secured to an excavating bucket. Further, operation of the equipment will cause the present wear assemblies to assume many different orientations. Nevertheless, for purposes of explanation, the components of the wear assemblies are at times described in regard to relative directions such as up and down. These directions should be understood with respect to the orientation of the wear assembly as shown inFIG. 2, unless stated otherwise.
Anadapter10 in accordance with the present invention is particularly designed for attachment to thefront lip12 of a bucket14 (FIG. 2). The lip includes an upper or insidesurface16, a lower oroutside surface17, afront edge face18, and abeveled ramp19 that interconnects insidesurface16 withfront edge face18.Adapter10 is secured tolip12 through the use of aboss24 and alock member26.
Boss24 is generally a J-shaped member with a pair oflegs28,29 which wrap around the lip of bucket14 (FIGS. 4-8).Upper leg28 has abody32 and alateral flange34 which together form a T-shaped structure along the top of the leg. The rear end ofleg28 forms a substantially flat,vertical wall36 which functions toabut lock member26 as discussed below; althoughwall36 could have a concave or convex shape. Theinner surface38 ofleg28 includes arear segment40 which preferably lies againstinside surface16 and afront segment41 which lies againstbeveled ramp19. Nonetheless, in some circumstances,leg28 may be fixed to the outside surface of the excavating equipment.
In the preferred construction,weld beads44 are secured along at least portions of the rear andfront segments40,41 to fixedly attach the boss to the bucket lip (FIG. 4). At least onehole46 is preferably provided throughupper leg28 to define an additional area for welding the boss to the bucket (FIGS. 5 and 6). A pair ofholes46a,46b (or other arrangements) could alternatively be formed if desired. For illustration purposes, this arrangement of holes has been shown in the perspective view of the boss (FIG. 4). Since the boss is substantially enveloped by the adapter, as described below, wearing of the boss is minimized. As a result, the boss requires only infrequent replacement. Welding of the boss to the lip is therefore not a significant deterrent to the operators in the field, unlike the welding of adapters which need frequent replacement. Alternatively, the boss can be fixed to the lip of the bucket by other means, such as bolting or being integrally cast with the lip construction. Also, particularly with cast bosses,lower leg29 can be omitted.
To form the T-shaped construction,body32 ofboss24 is narrower thanflange34. The lower portion ofleg28, however, again widens at the front end of the boss to form with leg29 aclamping section48. In the preferred construction, the width of clampingsection48 has substantially the same width asadapter10. Clampingsection48 includes atop brace49 andlower leg29 intersected to form a generally V-shape configuration. The widened clamping section provides increased support for holding the boss to the bucket, and enhanced support in resisting loads imposed on the adapter. Further,lower leg29 is short and positioned close toadapter10 so as to limit the exposure and wearing of the member. Although not illustrated,lower leg29 is in the preferred construction welded to outside surface27. The front ofboss24 is shaped to define abearing face52 that matingly abutsadapter10 as discussed below. Due to the connection ofbody32 withflange34 and with clampingsection48, bearingface52 has a generally I-shaped configuration (FIG. 4).
Adapter10 includes arearwardly extending leg54 and a forwardly projecting nose56 (FIGS. 1-3 and9-12).Nose56 is preferably formed as disclosed in U.S. Pat. No. 4,965,945 to Emrich, which is hereby incorporated by reference. Nevertheless, many other nose structures could be used as desired. In use, the socket defined in the point (not shown) is matingly received over the nose. In the illustrated embodiment, a lock pin (not shown) is passed alongshoulder57 to secure the point (not shown) to the adapter.
Adapter10 includes only asingle leg54 which preferably extends along the inside surface of the bucket. Ordinarily, the outside leg of atypical bifurcated adapter experiences much more wearing than the inside leg. By eliminating the need for a leg along the outside of the bucket, the adapters of the present invention generally enjoy a longer usable life. Nonetheless, in some circumstances,leg54 can be secured along the outside surface of the excavating equipment.Leg54 has aninner surface58 and anouter surface59. A T-shapedslot62 opens along theinner surface58 to matingly engage with the T-shaped configuration defined along the top of boss24 (FIGS. 3,11,12 and18). To installadapter10 on a bucket, the adapter is slid rearwardly ontoboss24 such thatslot62 is received over and aroundflange34. As an alternative, in certain circumstances, the T-shaped structures of the boss and the adapter may be formed as rail segments with spaced apart gaps therebetween as disclosed in U.S. Pat. No. 5,241,765 to Jones et al., which is hereby incorporated by reference. As discussed in this patent, the use of segments enables the wear member to be installed and removed with minimum longitudinal sliding of the adapter along the boss.
As can be appreciated,flange34 prevents movement of the adapter upward and away frominside surface16 ofbucket14. While themarginal edges64 ofinner surface58 generally follow the contour ofbucket lip12, the marginal edges do not have any significant engagement with the lip. In the preferred construction, agap66 is formed between most of themarginal edges64 ofadapter10 andbucket14 to permit sufficient space for the placement ofweld beads44.
A bearingface68 is positioned at the front end ofslot62 to abut against bearingface52 at the front of boss24 (FIGS. 2 and 10). In the preferred construction, bearing faces52,68 are oriented to be substantially perpendicular to theaxis70 ofnose56. With this arrangement, the magnitude of the moment forces to be resisted by the bearing surfaces can be minimized. Nevertheless, the angular orientation of bearingsurfaces52,68 could be varied considerably depending upon the desired application. Further, bearing faces52,68 both preferably extend belownose56 in order to better resist downwardly applied forces on the front of the point. Moreover, this downward extension of the bearing surfaces forms a front covering forclamp section48 ofboss24 which, in turn, reduces wearing of the boss. Finally, though bearing faces52,68 are generally planar, they could also be concave or convex in shape.
Anopening76 is provided inleg54 to extend fromouter surface59 toinner surface58 and communicate with slot62 (FIGS. 1 and 9).Opening76 is positioned nearrear end78 ofleg54, and rearward of rear bearing face36 ofboss24 whenadapter10 is assembled on the boss. In the preferred embodiment, opening76 has a generally T-shaped configuration which includes astem portion88 and across portion89. The cross portion is defined by a pair of opposing front andrear walls80,81 and a pair ofside walls82,83.Stem portion88 extends longitudinally betweencross portion89 andrear wall78. As discussed more fully below,stem portion88 provides clearance for theadjustment assembly92 oflock member26.Front wall80 of opening76 also preferably includes acentral recess94 to provide clearance for the front of the adjustment assembly as needed.
One of theside walls82 of the cross portion of opening76 defines akeeper96 to cooperate with alatch98 for releasably retaininglock member26 in the opening (FIGS. 12 and 18).Keeper96 is preferably formed by atab101 which overlies arecess103 adapted to receivelatch98. Theother side wall83 ofopening76 has an arcuated configuration which conforms with the arc of a circle to form a pivot support for inserting and removing the lock.Leg54 includes aspace105 belowside wall83 for receiving oneend107 oflock member26 as described below.
Lock member26 functions to preventadapter10 from being slid axially offboss24.Lock member26 has a rigid block-shapedbody108 defined by afront wall109, arear wall110, afirst end wall111, and a second end wall112 (FIGS. 14-16).Body108 oflock26 is received intocross portion89 of opening76 such that itsfront wall109 opposesrear wall36 ofboss24, and itsrear wall110 opposesrear wall81 of adapter10 (FIG. 1). This engagement structure effectively prevents the adapter from being moved forwardly along the boss.
Lock member26 further includes a latch98 (FIGS. 14,16 and18).Latch98 preferably includes arigid tang126 and anelastomeric member128.Latch98 is mounted within anopening130 inend wall111 such thattang126 projects outward therefrom. To facilitate removal of the lock from opening76, agroove131 is preferably defined inlock26 along the top ofend wall111 to enable a tool (e.g., a screw driver) to engage ashoulder133 ontang126 and retractlatch98 from keeper96 (FIGS. 15 and 16).Second end wall112 includes anarcuate depression132 which is adapted to matingly engage thearcuated end wall83, and enablelock member26 to pivotally swing into and out ofopening76. Whenlock member26 is inserted into opening76end portion107 is fit intospace105 to provide a larger abutting area (FIG. 18).
Lock26 further includes anadjustment assembly92 for eliminating any looseness that may exist between the adapter and the boss (FIGS. 14-16). In the preferred construction,adjustment assembly92 includes a threadedbore116 that extends throughlock member26 to receive a threadedplug118.Plug118 includesflats122 on its rear end to facilitate engagement with a wrench or the like and afront bearing face124. In use, plug118 is advanced throughbore116 until bearingface124 engagesrear wall36 ofboss24 andrear wall110 oflock member92 abutsrear wall81 ofopening76.Plug118 is preferably not tightened beyond engagement of the abutting walls to avoid unnecessary loading of theplug118. Moreover, since the plug is only loaded with compressive forces, the assembly has considerable durability and strength. As the adapter and boss wear, looseness may develop between the two parts. To eliminate this looseness, plug118 is advanced forwardly untilfront face124 ofplug118 again abutsrear wall36 ofboss24 andrear wall110 abutsrear wall81 ofopening76.
Alternatively, plug118 can be replaced with anadjustment assembly92a which relies upon fluid pressure to eliminate any existing looseness in the assembly (FIG. 17). More specifically, in this embodiment, lock member26a includes acylindrical cavity134 in lieu of threadedbore116. Apiston136 is slidably received incavity134 for movement toward and away fromrear wall36 ofboss24. A retainingring138 is threadedly attached incavity134 to form a stop against whichannular shoulder140 ofpiston136 engages upon maximum extension. Arear wall142 closes the cavity on its rear end and supportsgrease fitting144. Grease fitting144 is preferably set in a recess143 for protection. Grease or other fluid is fed intocavity134 to drivepiston136 forward. Acoil spring145 is received aroundpiston136 to retract the piston when the grease is drawn out ofcavity134.
The use of alock member26,26a with anadjustment assembly92,92a can also be used with other adapter constructions. For instance, with repositioning of the grease fitting, lock26a could be set in an opening of anadapter10′ without a stem portion (FIG. 13). As another example, the wear assembly can include anadapter170 and aboss171 which attaches to a bucket172 (FIGS. 19 and 20). The bucket lip174 includes generally parallel inside and outsidesurfaces176,177, and a roundedfront edge178.
Adapter170 includes a pair oflegs182,183 which extend along insidesurface176 and outsidesurface177, respectively, and a nose186 (FIGS. 19 and 20). Althoughnose186 preferably has the same construction asnose56 ofadapter10, it is shown with a nose in accordance with U.S. Pat. No. RE33042, incorporated herein by reference, to illustrate that different noses can be used.Top leg182 has alower surface189 that lies againstinside surface176 of lip174. A T-shapedslot191 opens inlower surface189 to receive a complementary T-shapedboss171. The rear end ofleg182 includes anopening195 which has the same construction asopening76.
A deflector201 (FIGS. 1-2 and21) is preferably secured toinside surface16 of bucket14 (or alternatively bucket172).Deflector201 is preferably a U-shaped member provided with aforward bracing surface203; although other structural members could be used. The deflector is used to ease the removal ofadapter10 in the field. In particular, lock26 (or26a) is removed from opening76, reversed, and set within thegap205 defined betweenrear end78 ofadapter10 and bracingsurface203 ofdeflector201. Theplug118 is then advanced so that itsbearing face124 pushes againstdeflector201 to movelock member26 forwardly into engagement withrear end78 ofadapter10. Continued advancement ofplug118 then functions to pushadapter10 fromboss24. Alternatively, other expansion devices (e.g., a turnbuckle) could be used with the deflector in lieu oflock26.
While use of a lock with an adjustment assembly is desired, it is not essential to the present invention. Theadapters10,170 can be amply secured toboss24,171 by a rigid lock without an adjustment assembly (not shown) that simply prevents forward movement of the adapter. Under these conditions, the lock member and corresponding opening would be essentially the same as discussed in U.S. Pat. No. 5,088,214 to Jones, which is hereby incorporated by reference. An example of such anadapter10′ is shown inFIG. 13. Nevertheless, a lock without an adjustment assembly could still be used inopenings76,195.
The above-discussion concerns the preferred embodiments of the present invention. Various other embodiments as well as many changes and alterations may be made without departing from the spirit and broader aspects of the invention as defined in the claims.