Shroud anchor system

A wear protector system for shielding the leading edge of an earthmoving implement such as a loading bucket includes an arrangement of shrouds which cover the leading edge between the laterally spaced digger teeth. Each shroud has a nose portion that wraps around the leading edge and a rearwardly extending tail portion having an abutment surface that engages an undercut abutment surface of an anchor block that is welded to the bucket. The complementary abutment surfaces retain the tail portion from moving upwardly away from the bucket surface, whereas the shroud is retained from movement forwardly out of engagement with the lip by use of a cotter pin extending transversely through a passage that is formed partially in the tail of the shroud and partially in the anchor.

BACKGROUND OF THE INVENTION 
a) Field of the Invention 
This invention relates to a new or improved wear protector system, and in 
particular to a replaceable assembly for protecting from wear the leading 
edge of an earthmoving implement such as a drag line bucket, a face 
shovel, buckets for front-end loaders, excavators and the like. 
b) Description of the Prior Art 
It has long been recognized that measures must be taken to protect the 
leading edge of earthmoving implements against wear. Typically these 
leading edges include a series of laterally spaced hardened digging teeth, 
and the sections of the leading edge between these teeth, if not protected 
are subject to rapid wear as a result of the abrasive environment in which 
the implement typically operates. The problems resulting from this wear 
can be reduced through the use of wear parts or shrouds designed to shield 
the leading edge, but provision must be made for securing such shrouds to 
the implement in a manner that reliably fastens them during operation yet 
allows for their easy removal and replacement when they become worn. Such 
shrouds are required to have high resistance to impact and to abrasion 
wear and are made of steel alloys which provide these properties. However 
such materials are not compatible with normal weld procedures and 
therefore the shrouds cannot be welded directly to the implement, e.g. a 
bucket lip. Mechanical fastening systems involving the provisions of holes 
through the bucket lip are undesirable because of the weakening effect of 
such holes. Accordingly it is known to provide a mounting system 
incorporating a mounting block or boss of a weldable steel which is welded 
to the bucket lip and to provide a mechanical attachment means for 
anchoring the shroud to the block. Examples of such wear protection 
systems can be seen in U.S. Pat. No. 5,088,214 Jones and U.S. Pat. No. 
4,748,754 Schwappach. 
The present invention provides a wear protector system for shielding from 
wear a portion of a leading edge of an earthmoving implement, said system 
including; an anchor for fixed welded attachment to a surface of said 
implement at a predetermined location rearwardly of said leading edge, 
said anchor comprising a block having a bottom surface for attachment to 
said implement surface, an undercut transverse forward first abutment 
surface, and an upper surface; and a shroud having a U-shaped nose and a 
rearwardly extending tail, said tail defining a transverse rearwardly 
facing second abutment surface that is complementary to said first 
abutment surface, said anchor and said shroud being configured to 
interengage when said anchor is fixed to the implement at said location 
such that the nose of the shroud lies against and extends around said 
leading edge; said anchor and said shroud having respective complementary 
channels, which, when said anchor and shroud are interengaged, together 
define a transverse passageway through which a tapered cotter pin can be 
inserted to retain said shroud in engagement with said anchor and with the 
leading edge of the implement. The complementary channels are mutually 
offset in the front-to-rear direction so that the cotter pin when engaged 
will urge the shroud rearwardly with a wedging action. 
The first abutment surface is preferably undercut by being inclined 
rearwardly from top-to-bottom, the mating abutment surface on the shroud 
being similarly inclined, this undercut configuration being effective to 
prevent the tail of the shroud rising out of contact with the anchor. 
Additional pairs of abutment surfaces may be provided to reinforce this 
effect, and preferably each abutment surface comprises a pair of facets 
that are angled to opposite sides forwardly or rearwardly with respect of 
the transverse direction to provide a centering effect of the shroud 
relative to the anchor. 
The profile of the cotter pin is preferably tapered along its length so 
that it can be driven in to the transverse passageway to varying degrees, 
and thus the arrangement, together with the offset in the channels of the 
shroud and the anchor, is capable of taking up any clearance that may 
arise in the mounting system as a result of wear during extended periods 
of service. Preferably the passageway is tapered from opposite sides 
towards its central area so that the cotter pin can be driven in from 
either side. To prevent accidental dislodgement of the cotter pin, 
preferably it is of a length sufficient that its leading end extends 
completely through the passageway and can be swaged over, this deformation 
preventing accidental withdrawal.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIG. 1, the bucket 10 of an earthmoving machine has a leading 
edge 11 along which are spaced a series of digger teeth 12 projecting 
forwardly of the leading edge at regular intervals, each tooth being 
mounted on an adaptor 13 which in turn is secured to the bucket lip in 
known manner. The regions of the bucket lip between the teeth require 
protection since they would otherwise be subjected to rapid wear because 
of the abrasive environment of operation, and for this purpose in each 
position a shroud 14 is provided. 
The configuration of the shroud 14 is seen more clearly in FIGS. 2 and 3 
and comprises a curved nose portion 15 and a rearwardly extending tail 
portion 16, the shroud being of substantially uniform width throughout its 
length. As seen in FIGS. 1 and 3, the nose 15 of the shroud is configured 
to lie in contact with the leading edge 11 and to shield the upper and 
lower surfaces 17, 18 of the bucket in the vicinity of the leading edge. 
As seen in FIG. 3 the leading edge portion of the bucket is formed with a 
pair of shallow grooves 19 extending therearound, the inner sides of the 
nose 15 being formed with a pair of ribs 22 that are sized to fit into the 
grooves 19. 
The tail 16 of the shroud has a rear end that is formed by two angled 
facets 23 which together have a wide angle V-shape configuration and which 
are angled slightly rearwardly from top-to-bottom. 
The underside of the tail 16 is recessed from the rear end forwardly to a 
front pair of rearwardly directed facets 24 which are likewise rearwardly 
inclined downwardly, and which together define a forwardly directed Wide 
V-configuration. 
Between the rear facets 23 and the front facets 24, the underside of the 
tail is formed by a generally flat horizontal surface 25. The acute angle 
corner region between the facets 24 and the surface 25 is enlarged by a 
parallel bore 26 designed to prevent debris from accumulating in this 
corner. 
A transverse groove 27 opens upwardly from the surface 25 and extends 
horizontally across the tail. This groove is of generally rectangular 
profile and tapers in width more or less uniformly from its opposite ends 
towards the center. 
An anchor block 28 has a chamfered undercut 29 extending across its lower 
edge at the rear and part way forwardly along both sides, and may be 
affixed to the surface 17 of the bucket by a weld bead applied along the 
length of this chamfer. In the forward portion of the block 28 there is a 
vertical through hole 30 through which a weld bead 31 may be applied to 
further attach the anchor to the surface 17. 
The configuration of the anchor 28 is complementary to that of the tail 16 
of the shroud and is shown most clearly in FIG. 4. Thus the forward part 
of the anchor has a V-shaped configuration formed by two angled facets 32 
which are inclined slightly rearwardly from top-to-bottom. A rear pair of 
angled facets 33 are likewise angled rearwardly from top-to-bottom and are 
arranged in a rearwardly pointing V-shape configuration. Between the pairs 
of facets 32 and 33 the anchor 28 has a horizontal top surface 34 from 
which opens a transverse channel 35 of generally rectangular profile, the 
channel tapering in width from its opposite ends towards its central 
region, as clearly seen in FIG. 3. 
In the assembled position, with the anchor block 28 welded to the upper 
surface 17 of the bucket 10 at a predetermined location and spacing 
rearwardly from the lip 11, the shroud 14 can be positioned over the lip 
11 as indicated in FIG. 1 and in intimate contact therewith, in which 
position the shroud tail portion 16 interengages with the anchor block 28 
as is clearly shown in FIG. 2. In this interengaged position the 
complementary facet pairs 24, 32 and 23, 33 of the shroud and anchor block 
respectively are in intimate abutting contact. In this configuration the 
rectangular grooves 27 and 35 are in confronting relationship and provide 
a through passage extending transversely between the shroud and the anchor 
block. As seen in FIG. 1, this passage is located rearwardly of the tooth 
adaptors 13, and accordingly is accessible for the insertion of a tapered 
cotter pin 36 into the passageway from either end. 
As will be clear from FIG. 2, in the engaged position of the shroud 14 on 
the anchor block 18, the confronting grooves 27, 35 are not in precise 
register, but rather are relatively offset in the front-to-rear direction 
of the shroud: specifically the shroud groove 27 is forwardly offset with 
respect to the anchor groove 35. In the engaged position a tapered cotter 
pin 35 can be inserted into the passageway defined by the confronting 
grooves 27, 35 and driven into wedging engagement therewith. As seen in 
FIG. 2, the upper part of the pin engages against the rear side of the 
shroud groove 27 and the lower part of the pin engages against the front 
side of the anchor groove 35 so that driving insertion of the cotter pin 
36 has the effect of pressing the shroud rearwardly and the confronting 
pairs of facets, and likewise the nose 15 of the shroud and the leading 
edge 11 of the bucket, into intimate engagement. The compressive forces 
caused by the wedge between the shroud and, the anchor block also act on 
the undercut complementary abutment surfaces in combination with the 
anchor and lip surface to produce a compressive joint. Thus, even should 
some degree of wear occur between these confronting facets, this can be 
taken up through the wedging action created by the cotter pin 36. The 
bores 26, and similar bores 37 between the facets 33 and the horizontal 
surface 34 of the anchor 28, allows for the escape of debris which 
otherwise might impair the intimate engagement of the confronting facets. 
Once the cotter pin 36 has been fully inserted, its thin nose portion 38 
can be swaged over to lie against the sides of the shroud 14 and anchor 
block 28 (these being of the same width) to prevent inadvertent loosening 
and withdrawal of the cotter pin. In the engaged position it will be 
evident that the shroud is securely held in contact with the region of the 
bucket surrounding the leading edge 11. The cotter pin 36 prevents forward 
movement of the shroud 14 relative to the anchor 28, whereas the undercut 
configuration of the confronting facets maintains the tail portion 16 of 
the shroud against any tendency towards upwards displacement. 
The pairs of angled abutment facets provide large bearing areas for 
absorbing thrust forces between the shroud and the anchor providing a 
means for transmitting shock and other loads from the shroud to the lip 
portion of the bucket 10. The forward or rearward lateral inclination of 
these facets also provides lateral stabilization of the shroud 14 relative 
to the bucket 10 without the need for additional locks or secondary 
engagement surfaces. This lateral stabilization is enhanced by the 
rib/groove 20, 19 interengagement between the nose of the shroud and the 
leading edge region of the bucket. The large areas of the interengaging 
facets have the effect of reducing compressive stress loads which in turn 
should reduce possible deformation and wear. However if wear does occur, 
the mounting arrangement allows for intermittent adjustment since such 
wear can be taken up simply by driving the cotter pin 36 further into its 
passageway.