BACKGROUND AND SUMMARY OF INVENTION:
[0001] This invention relates to a replaceable wear element and, more particularly, an element
for installation on the wearable part of a structure engageable with abrasive material.
[0002] This invention is an improvement of the arrangement shown in document EP-A-262856,
on which the precharacterizing part of claims 1,7 and 8 below are based. In that patent
document a pair of spaced apart transversely-aligned, convergent dovetails are employed
to provide a readily replaceable wear element which co-operates with a base on the
underside of an excavating bucket, scraper mold board, liner for an ore chute, or
the like. Such a wear element subject to wear may have to be replaced frequently,
a single base element outlasting a multiple of wear elements. The prior art assembly
of base and wear element is intended for installation in only one direction. This
does not serve the needs of operators in excavating, mining, etc. where reversibility
is required. The prior arrangements are not particularly convenient for use in certain
other applications whether or not reversibility is required.
[0003] The present invention is more particularly defined in the claims below. In some of
the embodiments of the invention the wear element is reversible. This makes possible
the utilization, for example, of a single wear element where previously two different
replacement elements had to be stored. For example, in the case of a bucket, it is
advantageous to provide a wear element that wraps around a corner and thus it is necessary
to have both right and left hand styles. Now, through use of the reversible elements
only a single replacement element is needed. This is a matter of some consequence
to operators because buckets are usually employed in primitive conditions and storage
facilities limited. Thus, anything that reduces the number of parts to be stored is
highly desirable.
[0004] Further, the four dovetail surfaces required some care in manufacture to develop
proper contact. Also, according to some of the embodiments described below there is
provided an arrangement of dovetail surfaces providing three contact areas. This results
in stability, fit and installation advantages.
BRIEF DESCRIPTION OF DRAWING:
[0005] The invention is described in conjunction with the accompanying drawing, in which
--
FIG. 1 is a perspective view of the prior art teaching of Patent EP-A-262 856;
FIG. 2 is a perspective, exploded view of the elements of the four point embodiment
of the instant invention;
FIG. 3 is a top plan view of the assembly of FIG. 4;
FIG. 4 is a fragmentary side elevational view of the inventive assembly as applied
to the corner of a bucket as would be seen along the sight line 4-4 applied to FIG.
3;
FIG. 5 is a perspective, exploded view of a modified form of the four point invention
with the assembled base element shown in dashed line;
FIG. 5A is a schematic representation of the showings in FIGS. 2 and 5 interrelated
to show corresponding dovetail segments;
FIG. 6 is a top plan view of a modified form of the invention seen in FIG. 5; and
FIG. 7 is a sectional view seen along the sight line 7-7 applied to FIG. 6;
FIG. 8 is a schematic top plan view of a series of wear assemblies to illustrate alternative
four point constructions;
FIG. 9 is a schematic top plan view of the construction of FIG. 2, illustrating disassembly;
FIG. 9A is a schematic top plan view of the construction of FIG. 6, illustrating disassembly
thereof;
FIG. 10 is a view similar to FIG. 8 but with the upper and lower sides transposed
approximately one-third period to illustrate the three-point construction;
FIG. 11 is a top plan view of the base element as would be developed by cutting along
the lines 11, 11 of FIG. 10;
FIG. 11A is a top plan view of the base element as would be developed by cutting along
the lines 11A, 11A of FIG. 10;
FIG. 13 is an end elevational view of the assembly of each of FIGS. 12 and 14;
FIG. 14 is a top plan view of a modified form of the three point invention;
FIG. 15 is an exploded top plan view of the three point inventive assembly;
FIGS. 16-18 are exploded top plan views of the FIG. 14 assembly in the process of
assembly;
FIG. 19 is a fragmentary side elevational view of a further modification of the three
point invention useful as a cutting edge for a mold board;
FIG. 20 is a fragmentary front elevational view of the assembly of FIG. 19; and
FIG. 21 is a fragmentary exploded plan view of the elements of FIGS. 19 and 20 showing
the mode of assembly.
DETAILED DESCRIPTION:
[0006] In the illustration given and with reference first to FIG. 1 which is entitled PRIOR
ART, the symbol A designates the base element as seen in Patent EP-A-262 856 and the
symbol B designates the wear element -- in this case a runner for the underside of
a dragline bucket. The arrow designated C shows the path through which the element
B is moved in being installed on the base element A, i.e., it is first moved upwardly
into general co-planar relation and thereafter slid rearwardly so as to engage the
two pairs of mating dovetails, D and E on element A and D' and E' on element B. The
two pairs of dovetail elements are separated by a notch F.
[0007] Now referring to FIG. 2, the numeral 10 designates generally a base element while
the numeral 11 designates generally the wear element. In the illustration given, the
base element 10 includes a generally plate-like body 12 which is relatively elongated
to provide end walls 13, 14 and sidewalls 15, 16. One body surface 17 is the inner
surface which normally would be secured to the wearable part of a structure such as
the corner portion 18 of a bucket (see FIG. 4) or other structure 318 (see FIG. 13).
The outer surface opposite to the attached surface 17 can-be seen only in FIG. 4 and
is designated 19 and constitutes the surface in confronting relation to the wear element
11.
[0008] The wear element 11 has corresponding body, walls and surface parts -- designated
by the same numerals, but with the addition of a prime ('). Thus, in FIG. 3, the body
of the wear element 11 is 12', the end walls 13' and 14' and the sidewalls 15' and
16'. The inner surface 17' (see FIG. 4) is the surface confronting the base element
10 while the outer surface 19' is the one engageable with abrasive material.
[0009] Still referring to the base element 10 of FIG. 2, it will be noted that the body
is equipped with integral transversely extending flanges as at 20, 21, 22 and 23 separated
by relatively longitudinally elongated notches 24 and 25. The extremities of the flanges
20-23 are shaped to provide divergent/convergent dovetail surfaces. In other words,
the surfaces are doubly sloped -- both in the top to bottom direction of the normal
dovetail and also sloped fore/aft to provide the divergence/convergence. The dovetail
surfaces employed herein are like those in the previously mentioned Patent EP-A-262
856 and express reference is hereby made to that patent for additional details of
structure and operation.
[0010] Illustrative of the dovetail surfaces is the outer wall or surface 26 of the flange
portion 22 in the base element 10 (see the central right hand portion of FIG. 2).
When the wear element 11 is moved into engagement with the base element 10 -- as illustrated
by the curved arrows 27 in FIG. 2 -- the flange 22 is received within the notch 28.
Then, when the wear element 11 is moved in the direction of the arrow 29, the dovetail
surface 26 engages a mating surface 30 in the wear element 11. Normally, the elements
10, 11 are positioned as seen in FIG. 2 when the normal flow of abrasive material
is in the direction of the arrow 29 -- which tends to seat the dovetail surfaces 26,
30 more firmly against each other. More properly, such movement includes the seating
engagement of the dovetail surface 31 (the mirror image of the dovetail surface 30)
against the dovetail surface provided at the extremity of the flange 20; and in similar
fashion, the dovetail surface 32 on the wear element 11 is seated on the dovetail
surface 33 on the flange 23 of the base element 10 and, in like fashion, the dovetail
surface 34 is seated against the dovetail at the extremity of the flange 21 on the
base element 10.
[0011] We have found it advantageous to incline the surfaces 30, 31, 32 and 34 at an angle
of about 15° relative to the longitudinal center line 35 of the wear element 11. It
is to be understood that the mating dovetail surfaces as at 26, 33, etc. on the base
element are similarly inclined to the longitudinal center line (not shown) of the
base element 10. In some instances, we have found it to be further advantageous to
alter somewhat the angle included between the centerline and dovetail surfaces to
the range of about 10° to about 20° to insure better fits and easier release of the
wear element.
[0012] Also assisting in developing better fits are the provision of rails 11a (see FIG.
4) on the surface of the wear element confronting the base element 10. These also
can be seen in perspective in FIG. 1 adjacent the outstanding walls G and H and are
designated by the symbol I.
[0013] The operation described thus far is very much like that achieved through the practice
of the arrangement shown in EP-A-262 856. To obtain the advantageous reversibility
we provide additional dovetail surfaces as at 36, 37 just to the right of the transverse
centerline 40 in FIG. 2 and as at 38 and 39 at the left of the wear element 11. It
will also be noted that the dovetail surfaces are symmetrical about the transverse
center line 40 as they also are about the longitudinal center line 35. Therefore,
as the wear element 11 is rotated 180°, it would have the same appearance as that
shown in FIG. 2 but with the dovetail surface 39 now being in the place of the dovetail
surface 30, the dovetail surface 37 occupying the position of the dovetail surface
32, etc.
[0014] The dovetail surfaces in the wear element 11 are provided by outstanding wall portions
as at 41 and 42 in a fashion similar to that provided at G and H in FIG. 1 relative
to the prior art. More particularly, the surface remote from that being abraded is
equipped with transversely-spaced, integral outstanding portions which provide confronting
walls carrying the various dovetails. These confronting walls are mirror images and
spaced equally away from the longitudinal center line 35. These confronting walls
are equipped with two pairs of longitudinally spaced, substantially identical, transversely
aligned notches intermediate the ends of the wear element 11. For example, one pair
of notches is designated 28, 43 and the other pair 44, 45.
[0015] It will be seen that each notch is flanked at both longitudinal ends thereof by a
dovetail surface segment of the opposed or confronting wall providing the same --
with each of the segmental flanking surfaces being convergently related to its longitudinal
center line in proceeding away from its associated notch. This is illustrated by considering
the dovetail surfaces 30, 36 as the segments referred to in connection with the notch
28 and the center line 35. The same applies to the segments 32, 38 relative to the
notch 44, the segments 34, 39 relative to the notch 45 and the segments 31, 37 relative
to the notch 43.
[0016] The reversibility of the wear element 11 relative to the base element 10 not only
is advantageous in the case of left and right mountings as in FIG. 4 where the body
12' is extended transversely of the length of the dovetail along one sidewall to go
around a corner as at 12'' but also in the case of wear elements in general. Where
the wear elements are flat but subjected to abrasive forces in only one longitudinal
direction, wear normally occurs more at the lead portion than the trailing portion.
Therefore, switching the wear element end for end effectively extends the life thereof.
In the case of the right and left hand elements of the character seen in FIGS. 3 and
4, the reversible feature is especially advantageous because these normally are quite
extensive and ponderous, sometimes necessitating an integral eye as at 46 to lift
the same into position on the associated bucket 18.
[0017] An alternative arrangement can be seen in FIG. 5 which is advantageously employed
where the length of the wear element is a restriction. This is achieved in the wear
element 111 of FIG. 5 by the elimination of one pair of notches, utilizing only the
notches 128 and 143. As before in the case of the illustration of FIG. 2, the illustration
of FIG. 5 makes use of opposed or confronting walls 147 and 148 corresponding to walls
47, 48 of FIG. 2 which are again symmetrically related to the longitudinal center
line 135. These are provided by upstanding integral portions as at 141 and 142. Further,
and again as in the instance of the showing in FIG. 2, the confronting walls 147,
148 are symmetrical about the transverse center line here designated 140.
[0018] Again, there are four pairs of dovetail surfaces but here the arrangement is somewhat
different. The arrangement of the dovetail surfaces is the same in the respect that
flanking the notch 128 are the surfaces 136 and 130 much the same as the surfaces
36 and 30 flank the notch 28 in FIG. 2. Also in proceeding to the left, a further
dovetail surface or wall segment 132 extends to the left of the segment 136 just as
the surface 32 extends to the left of the surface 36 in FIG. 2. However, the segment
38 of FIG. 2 has been relocated from the left hand end to the right hand end as at
138 in FIG. 5. More particularly, the opposed sidewalls 147 and 148 are arranged in
two longitudinally spaced pairs of segments separated by a notch in each wall. Each
wall of each pair includes two angularly related wall segments with the wall segment
immediately adjacent the notch being convergently-related (in proceeding away from
the notch) to its transversely aligned wall segment (130 versus 131) with the wall
segment spaced from the notch being divergently related to its transversely aligned
wall segment (138 versus 139).
[0019] Common to both constructions is the fact that each notch is flanked at both longitudinal
ends by a segment of the confronting wall with each of the flanking segments being
convergently related to the longitudinal center line in proceeding away from the associated
notch. Further, each confronting wall remote from the notch has two additional segments
for cooperation with the flanking segments in reversibly mounting the body on the
base element 10, 110.
[0020] The notches and segments are constructed as having approximately the same length
with the first of the additional segments being spaced approximately two lengths from
a first of the flanking segments and the second of the additional segments being spaced
approximately two lengths from the second of the flanking segments with the first
flanking and additional segments being parallel and the second and additional segments
being parallel.
[0021] The foregoing can be appreciated from a consideration of FIG. 5A which is a schematic
top plan view of the showings in FIGS. 2 and 5 arranged to show corresponding elements,
viz., the notches 28 and 128 being aligned as are the segments 30, 130, the segments
32, 132 and the additional segments 36, 136. The additional segments previously referred
to include the segments 136 and 138 in the case of the schematic view of FIG. 5. The
segment 132 cooperates with, i.e., is parallel to, the segment 130 and is spaced two
lengths 1 therefrom. In the same fashion, the additional segment 138 is related to
the flanking segment 136. Thus it will be seen relative to the showing in FIG. 5 that
the additional segments are on opposite sides of the notch 128.
[0022] Still referring to FIG. 5A and in the case of the schematic representation of FIG.
2, the flanking segments are 36 and 30 with the additional segments being 38 and 32.
It will be noted that the segment 38 is spaced two lengths from the segment 36 and
is parallel thereto while the segment 32 is spaced two lengths from the segment 30
and again is parallel thereto.
[0023] It may be easier to understand the bi-directional dovetail constructions and features
by noting that the variations are based on a repetitive pattern as seen in FIG. 8.
For instance, one gets the base/runner combination of FIG. 2 if the FIG. 8 showing
is cut along the section lines 2'-2' and 2''-2''. One gets the base/runner combination
of FIG. 5 if one cuts at 5'-5' and 5''-5''. One gets the base/runner combination of
FIG. 6 if one cuts at 6'-6'-6''-6''. In all cases one gets a base/runner combination
that is reversible. One can choose to cut where necessary to obtain specific objectives
such as an assembly with dovetails shifted towards the front, towards the rear, or
an assembly that is more compact when individual mounting is permissible (as opposed
to serial mounting).
[0024] In the case of the embodiment of FIG. 2, it is possible to arrange the wear elements
11 in a continuous series -- as in a wear runner for a dragline bucket, a lining for
an ore chute, etc., with the end of one wear element abutting the other -- and still
provide the necessary sliding movement for removal when the same are removed serially.
This is because the base 10 in FIG. 9 allows the wear element 11 to move the necessary
distance M forward to disengage without blocking its movement with any necessary placement
of dovetails of the base 10. However, to serially employ the embodiment of FIG. 5,
end projections are added as at 249 and 250 on the wear element 211 of FIGS. 6 and
7 for movement relative to the base element 210. FIG. 9A shows this version with end
projections and the movement M' needed to disengage dovetails and remove the wear
element.
Three Point Embodiment
[0025] First, it should be appreciated that FIG.8 on the four point embodiment shows a repeating
pattern for the base and wear elements which can be cut in any of a various number
of places and still be a useable base runner assembly. However, there are other ways
to cut the continuous segment. FIG. 10 shows the first step -- that of shifting one
outstanding wall 442 longitudinally relative to the other wall 441. This develops
an offset J not present in the four point embodiment.
[0026] FIGS. 10, 11 and 11A will be referred to later after the details of the three point
embodiment have been described. Now referring to FIG. 12 which illustrates the three-point
assembly of the instant invention, the numeral 310 designates generally a base element
while the numeral 311 designates generally the wear element. In the illustration given,
the base element 310 includes a generally plate-like body 312 which is relatively
elongated to provide end walls 313, 314 and sidewalls 315, 316. One body surface 317
(see FIG. 13) is the surface which normally would be secured to the wearable part
of a structure 18.
[0027] The surface opposite to the attached surface 317 can be seen only in FIG. 13 and
is designated 319 and constitutes the surface in confronting relation to the wearable
element 311. As in the case of FIG. 2, the body, wall and surface parts of the wear
element are designated by the same numerals as those of the base element but with
the addition of a prime ('), viz., 312'-317' and 319' or 412'-417' and 419'.
[0028] Still referring to the base element 310 of FIG. 12, it will be noted that the body
sidewall 315 is equipped with integral transversely extending flanges as at 322 and
323 separated by a relatively longitudinally elongated recess 324. The extremities
of the flanges 322, 323 are shaped to provide divergent/convergent dovetail surfaces.
[0029] Another flange 320 extends from the opposite body sidewall 316 and its extremity
is also shaped to provide a divergent/convergent dovetail surface. Flange 320 is transversely
aligned with the recess 324 -- so that flange 320 is intermediate the length of the
body 312 while the flanges 322, 323 are adjacent the ends thereof. An important difference
in the FIG. 12 showing from that of FIG. 2 is that there is only one flange extending
transversely from the sidewall 316. In other words, there is no counterpart for the
flange 21. Each of the flanges has an outer convergent/divergent dovetail surface.
[0030] Illustrative of the dovetail surfaces is the outer wall or surface 326 of the flange
portion 322 in the base element 310 or 410 (see also the upper right portions of FIGS.
14 and 15). The showing in FIGS. 14 and 15 differs from that of FIG. 12 in that the
recess 424 is much shorter than the recess 324, and the flange 420 is shorter than
the flange 320.
[0031] The embodiment of FIGS. 14 and 15 permits both the same and a different type of mounting
of the wear element 411 on the base element 410 from that illustrated in the prior
art of FIG. 1. There, the notch F is aligned with the dovetail E, the wearable element
B moved into engagement with the stationary base A and then moved rearwardly as indicated
by the arrow C. The normal material flow is from right to left in the FIG. 1 illustration.
[0032] For mounting of the wear element 411 on the base element 410 notches 428 and 443
can be employed just as notches 28, 43 are employed in FIG. 1. The description of
FIGS. 14, 15 applies also to FIG. 12 but certain reference numerals have been omitted
in FIG. 12 for clarity. The notches 428, 443 are provided in the outstanding sidewall
portions 441, 442, respectively -- see FIG. 15. These correspond in general to the
notch F in the outstanding wall portion G of the prior art of FIG. 1. By positioning
the wearable element 411 so that the notch 428 is aligned with the flange 422 and
the notch 443 is aligned with the rear end of the flange 420, the wear element 411
can be mounted on the base element 410. Thereafter the wearable element 411 is slid
rearwardly (to the left in FIG. 15) along centerline 435 so as to bring the various
dovetail surfaces into mating engagement. Again, we use the term rearwardly in the
context of the direction of normal material flow -- designated in FIG. 15 by the arrow
429. This results in increasing seating engagement between the dovetail surfaces on
the wear element 411 and the base element 410. In this engagement the dovetail surface
430 mates with the dovetail surface 426 on the base element 410. Further, the dovetail
surface 432 mates with the flange dovetail surface 433 and the dovetail surface 434
mates with the dovetail surface 451 on flange 420.
[0033] Also, the embodiment of FIGS. 14 and 15 can be employed to mount the wear element
411 on the base element 410 without utilizing notches as in the prior art as seen
in the following alternative.
ALTERNATIVE MOUNTING
[0034] This alternative action of mounting the wear element 411 on the stationary base element
410 is illustrated in the sequence of views FIGS. 16-18. In FIG. 16, for example,
it will be seen that the wear element 411 is oriented so as to have its longitudinal
center line 435a at a minor acute angle to the center line 435 of the base element
410.
[0035] Then in FIG. 17, the wear element 411 is moved rearwardly onto the base element 410
in the direction of the arrow 429 and also the direction of normal material flow.
Then the wear element 411 is rotated (clockwise as shown in FIG. 17) to bring the
center lines 435a, 435 into alignment so that seating engagement of the various dovetail
surfaces can be effected by further movement of the wear element 411 to the left as
indicated in FIG. 18 along the center lines 435, 435a.
[0036] The dovetail surfaces on the base element 410 can be seen most clearly at the left
hand end of FIG. 18. There, the numeral 433 designates the dovetail surface on the
flange 423 -- the flange 423 being identical to the flange 323 of FIG. 12, and the
flange 422 carrying the surface 426 is identical to the flange 322. Projecting from
the opposite sidewall 416 is the flange 420 which, at its extremity, carries the dovetail
surface 451.
[0037] Cooperating with these surfaces are confronting surfaces on the wear element 411.
In the outstanding wall portion 441 -- see the right hand side of FIG. 15 -- the surface
430 engages the surface 426, the surface 432 engages the surface 433 and the surface
434 engages the surface 451. So the first wall 447 has a pair of longitudinally spaced
apart dovetail surfaces 430, 432 which are inclined at a positive angle to the center
line 435 (see FIG. 15). The second of the opposing walls, 448 has a single dovetail
surface 434 which is inclined at a negative or reverse angle to the center line 435
and is positioned intermediate the adjacent ends of the pair of dovetail surfaces,
430, 432 on the first opposing wall 447.
[0038] In FIG. 12, by providing the longer recess 324 (versus the shorter recess 424 of
FIG. 14) and the longer flange 320 (versus the flange 420) we are able to make the
dovetail surface 351 approximately equal to the sum of the dovetail surfaces 326,
333. In contrast, the dovetail surface 451 in FIG. 15 is approximately the same longitudinal
extent as each of the pair of surfaces 426, 433. The equalization of the single dovetail
surface with the pair of dovetail surfaces (FIG. 12) makes possible somewhat greater
holding power.
Reversibility
[0039] For the purpose of enabling the wear element 311, 411 to be mounted with either end
positioned forwardly, the opposing walls 447, 448 are arranged to have the same contour
when they are rotated 180°.
[0040] To achieve the dovetail surface engagement upon reverse positioning of the wear element
311, 411, three additional dovetail surfaces are provided. For example, the dovetail
surface 436 (see FIG. 15) corresponds to the dovetail surface 434 and the pair of
surfaces 439 and 437 correspond to the surfaces 430, 432.
[0041] It will be noted that the dovetail surfaces 430, 432 and the reverse-operation corresponding
surfaces 437, 439 are adjacent the ends of the generally plate-like body 412' (see
FIG. 15) constituting the wear element 411 (or, for that matter, the wear element
311). Also, irrespective of whether either end is positioned first, the pair of dovetail
surfaces 430, 432 or 437, 439 has a dovetail surface positioned immediately forward
of a notch 428, 443, as the case may be. Also, the notch 443 is immediately rearward
of the dovetail surface 434 when one front wall is positioned forwardly and, when
the element 411 is rotated 180°, the single dovetail surface 436 is immediately forward
of the notch 428.
Mold Board Attachment
[0042] The invention finds advantageous application to wear elements in earth working such
as the mold board 518 of FIGS. 19-21. There, it is most desirable to provide a sharp
bottom cutting edge and this is achieved by installing on moldboard 518 a plurality
of wearable elements in side-by-side relation as at 511 in FIG. 20. Again, the wear
element 511 has side and end walls and top and bottom surfaces -- designations omitted
for clarity.
[0043] For this purpose, the mold board 518 is equipped with a plurality of base elements
510 in horizontal side-by-side relation. Again, each base element 510 includes a generally
plate-like body 512 (see FIG. 21) which is generally elongated to provide end walls,
sidewalls, and top and bottom surfaces as in the previous embodiments of the invention.
One base element sidewall 515 (positioned upwardly in FIG. 21) has generally the contour
of the previously-described embodiments, viz., convergent/divergent dovetail surfaces
526 and 533 separated by a notch 524 (see FIGS. 20 and 21). However, the other sidewall
surface 516 is not dovetailed but has a planar wall which merely confronts an interior
shoulder 552 on the wear element 511. The other dovetail engagement of the wear element
is achieved with the moldboard 518 as at 553 -- see the lower portion of FIG. 19.
[0044] The connection of the wear element 511 to the base element-equipped moldboard 518
can be best appreciated from a consideration of FIG. 21 -- particularly, the perspective
view of the wear element 511 shown in the process of installation along the line 529
which is parallel to the longitudinal centerline 535.
[0045] First as seen in the lower left portion of FIG. 19, the moldboard has a beveled bottom
edge as at 554 which is parallel to the ground and which may be equipped with bolted
on cutting edges. This edge 554, effect, provides a dovetail surface which mates with
the straight dovetail surface 548 provided on the wear element 511 -- see the lower
right portion of the separated element in FIG. 21. In other words, the dovetail-providing
surface 548 is not divergent/convergent as in the other embodiments of the invention.
However, the wear element has outstanding wall portions as at 541 and 542. The wall
portion 541 has a wall 547 which is equipped with the divergent/convergent surfaces
530, 532 separated by the notch 528 -- as in the previous embodiments. The walls 548,
554 extend parallel to the longitudinal centerline of the wear elements 511.
[0046] By longitudinal centerline, reference is again to the direction of movement of the
wear element when it is installed. This is illustrated by the arrow segment designated
529 in FIG. 21. Depending upon the object of the designer, the longer dimension of
the wear element may be either in the direction of movement for installation or transverse
thereto.
[0047] For installation, the flange-like outstanding wall portion 542 at the bottom of the
wear element 511 is hooked under the moldboard bottom wall 554 with the notch 528
aligned with the dovetail surface 533. The wearable element 511 is then pivoted to
place the dovetail surface 533 in the notch 528 and thereafter the wear element 511
is slid to the right (as depicted in FIG. 21). When the wear elements 511 are assembled
side-by-side, they serve to lock each other with the most outboard wear elements being
locked in place by bolts or welds. Because of the dovetails being in only one of the
upstanding walls, the dovetail angles do not have to be at the same convergence/divergence
which relieves the need for exact tolerances.
[0048] A variety of dovetail arrangements are possible while still following the basic teaching
of the invention. Focusing on the wear element and, more particularly, the outstanding
wall portions 41, 42 of FIG. 8 or 441, 442 of FIG. 10, this teaching includes the
provision in one wall portion for a pair of spaced apart dovetail surfaces 30, 32
(FIG. 8) or 430, 432 (FIG. 10). These are advantageously arranged at a positive angle
to the longitudinal centerlines 35, 435, respectively. On the other side of the longitudinal
centerline, the second wall portion 42, 442 is equipped with a surface 37, 434, respectively,
that confronts the dovetail surfaces in the first wall portion 41, 441. This surface
37, 434 is positioned intermediate the spaced apart surfaces 30, 32 or 430, 432.
[0049] As just pointed out with reference to the mold board attachment (FIGS. 19-21) this
confronting surface may be a bevel or straight dovetail surface 548. When the confronting
surface 434 is arranged at a negative angle with respect to the centerline 435 of
FIG. 10, it provides the third surface of the three point embodiment (see FIG. 15
also).
[0050] By flanking the surface 434 with surfaces 437, 439 which are arranged at a positive
angle relative to the centerline 435 and providing the counterpart negative angle
surface 436 between the surfaces 430, 432, reversibility is achieved.
[0051] This three point repeating configuration can be adjusted to obtain stackability,
viz., serial mounting as in FIGS. 9 and 9A. This is achieved by elongating the base
element as at 610 in FIG. 10 and adding partial notches 649, 650, 666, 667. The resulting
base element is seen in FIG. 11A and reflects the three-point construction.
[0052] Cutting the repeating pattern to develop the base element 710 (see the left hand
portion of FIG. 10) permits the achievement of the four point embodiment. This wear
element 711 is seen in FIG. 10 and corresponds generally to the showing of the wear
element 211 of FIG. 6. However, the notches in opposing walls are not aligned, but
offset. In FIG. 6, there is a zero offset while in FIG. 11 the offset is 1/3 a period.
A period is the distance between any two similar or corresponding points, i.e., between
the centers of two adjacent notches, the peaks of adjacent dovetails, etc. This can
be appreciated from the symbol J applied to the left hand portion of FIG. 10 and this
may extend up to 1/2 a period.
[0053] This offset J can be controlled depending upon situation and function desired. This
repeating pattern can then be cut at an opportune place to provide a base/wear element
combination that is both stackable and reversible as well as providing three point,
four point and multiple point contact.
1. A replaceable wear element (11, 111, 211, 311, 411, 711) for installation on the wearable
part (18) of a structure engageable with abrasive material comprising:
a unitary generally rectangular plate-like body (12', 412') having end walls (13',
14', 313', 314', 413', 414'), sidewalls (15', 16', 315', 316', 415', 416') and top
and bottom surfaces (17', 19', 317', 319', 417', 419'), one of said surfaces (19',
319', 419') being adapted to engage said abrasive material,
the other (17', 317', 417') of said top and bottom surfaces being adapted to be positioned
in confronting relation to said wearable part by movement generally along its longitudinal
centerline (35, 135, 435),
said other surface (17', 317', 417') adjacent both sidewalls (15', 16', 315', 316',
415', 416') being equipped with transversely-spaced, integral outstanding portions
(41, 42, 141, 142, 441, 442) providing a central slot with opposing walls (47, 48,
147, 148, 447, 448),
a first set of dovetail surfaces (30, 32, 34, 130, 132, 134, 430, 432, 434) including
a pair of longitudinally spaced apart dovetail surfaces (30, 32, 130, 132, 430, 432)
inclined at a positive angle to said centerline (35, 135, 435) on a first of said
opposing walls (47, 147, 447) and at least one dovetail surface (34, 134, 434) inclined
at a negative angle to said centerline (35, 135, 435) on the second (48, 148, 448)
of said opposing walls, said first set of dovetail surfaces cooperating to receive
and securely engage complimentary surfaces of a cooperating element (10, 110, 210,
310, 410, 710) fixed to said wearable part (18) due to relative movement of said wear
element in a first longitudinal direction,
characterized by a second set of dovetail surfaces (36, 37, 39, 136, 137, 139,
436, 437, 439) including at least one dovetail surface (36, 136, 436) inclined at
a negative angle to said centerline (35, 135, 435) on said first opposing wall (47,
147, 447) and a pair of longitudinally spaced apart dovetail surfaces (37, 39, 137,
139, 437, 439) inclined at a positive angle to said centerline (35, 135, 435) on the
second opposing wall (48, 148, 448), said second set of dovetail surfaces cooperating
to receive and securely engage complimentary surfaces of the cooperating element (10,
110, 210, 310, 410, 710) due to relative movement in a second longitudinal direction.
2. A replaceable wear element (11, 111, 211, 311, 411, 711) in accordance with claim
1 wherein each said opposing wall (47, 48, 147, 148, 447, 448) includes at least one
notch (28, 43, 128, 143, 428, 443) for allowing access of said cooperating element
(10, 110, 210, 310, 410, 710) between said opposing walls (47, 48, 147, 148, 447,
448).
3. A replaceable wear element (11, 111, 211, 311, 411, 711) in accordance with claim
2 wherein each notch (28, 43, 128, 143, 428, 443) is flanked at both of its longitudinal
ends by one of said dovetail surfaces (30, 31, 36, 37, 130, 131, 136, 137, 430, 431,
436, 437), each said dovetail surface associated with a notch converges toward said
centerline (35, 135, 435) as said dovetail surface extends away from said notch.
4. A replaceable wear element (11, 111, 211, 711) in accordance with claim 1 wherein
said first set of dovetail surfaces includes a pair of spaced apart dovetail surfaces
(31, 34, 131, 134) inclined at a negative angle to said centerline (35, 135) on said
second opposing wall (48, 148) and said second set of dovetail surfaces includes a
pair of spaced apart dovetail surfaces (36, 38, 136, 138) inclined at a negative angle
to said centerline (35, 135) on said first opposing wall (47, 147).
5. A replaceable wear element (311, 411) in accordance with claim 1 wherein said dovetail
surface (434) inclined at a negative angle to said centerline (435) on said second
opposing wall (448) is positioned longitudinally between said pair of dovetail surfaces
(430, 432) inclined at a positive angle to said centerline (435) on said first opposing
wall (447).
6. A replaceable wear element (311, 411) in accordance with claim 5 wherein said dovetail
surface (436) inclined at a negative angle to said centerline (435) on said first
opposing wall (447) is positioned longitudinally between said pair of dovetail surfaces
(437, 439) inclined at a positive angle to said centerline (435) on said second opposing
wall (448).
7. A replaceable wear element (511) for installation on the wearable part (518) of a
structure engageable with abrasive material comprising:
a unitary plate-like body having end walls, sidewalls, and top and bottom surfaces,
onc of said surfaces being adapted to engage said abrasive material,
the other of said top and bottom surfaces being adapted to be positioned in confronting
relation to said wearable part by movement generally along its longitudinal centerline
(535),
said other surface adjacent both sidewalls being equipped with transversely-spaced,
integral outstanding portions (541, 542) providing a central slot with opposing walls
(547, 548),
a first (547) of said opposing walls having a pair of longitudinally spaced apart
dovetail surfaces (530, 532) inclined at a positive angle to said centerline (535),
characterized by the second (548) of said opposing walls having a dovetail surface
(548) generally parallel to said centerline and extending entirely across said second
opposing wall.
8. A replaceable wear element (311, 411) for installation on the wearable part (18) of
a structure engageable with abrasive material comprising:
a unitary generally rectangular plate-like body (312', 412') having end walls (313',
413', 314', 414'), sidewalls (315', 415', 316', 416') and top and bottom surfaces
(317', 417', 319', 419'), one of said surfaces (319', 419') being adapted to engage
said abrasive material,
the other (317', 417') of said top and bottom surfaces being adapted to be positioned
in confronting relation to said wearable part by movement generally along its longitudinal
centerline (335, 435),
said other surface (317', 417') adjacent both sidewalls (315', 415', 316', 416') being
equipped with transversely-spaced, integral outstanding portions (441, 442) providing
a central slot with opposing walls (447, 448),
a first (447) of said opposing walls having a pair of longitudinally spaced apart
dovetail surfaces (430, 432) inclined at a positive angle to said centerline (435),
characterized by the second (448) of said opposing walls having a dovetail surface
(434) inclined at a negative angle to said centerline and being generally positioned
intermediate the inner ends of said first opposing wall pair of dovetail surfaces
(430, 432) to thereby permit a cooperating element to be inserted obliquely in the
end of the groove and then straightened to cooperate with said dovetail surfaces.
1. Auswechselbares Verschleißelement (11, 111, 211, 311, 411, 711) zur Installation an
dem Verschleißteil (18) einer Konstruktion, die mit einem Abrasionsmaterial eingreifen
kann, wobei das Element folgendes umfaßt:
einen unitären, allgemein rechteckigen, plattenartigen Körper (12', 412') mit Endwänden
(13', 14', 313', 314', 413', 414'), Seitenwänden (15', 16', 315', 316', 415', 416')
und oberen und unteren Oberflächen (17', 19', 317', 319', 417', 419'), wobei eine
der Oberflächen (19', 319', 419') dazu geeignet ist, mit dem Abrasionsmaterial einzugreifen,
wobei die andere Oberfläche (17', 317', 417') der oberen und unteren Oberflächen durch
eine Bewegung allgemein entlang ihrer longitudinalen Mittellinie (35, 135, 435) gegenüber
dem Verschleißteil positioniert werden kann,
wobei die genannte andere Oberfläche (17', 317', 417') neben beiden Seitenwänden (15',
16', 315', 316', 415', 416') mit transversal beabstandeten, integralen, hervorstehenden
Teilstücken (41, 42, 141, 142, 441, 442) ausgestattet ist, die einen zentralen Schlitz
mit entgegengesetzten Wänden (47, 48, 147, 148, 447, 448) vorsehen;
eine erste Gruppe schwalbenschwanzförmiger Oberflächen (30, 32, 34, 130, 132, 134,
430, 432, 434) mit einem Paar longitudinal beabstandeter schwalbenschwanzförmiger
Oberflächen (30, 32, 130, 132, 430, 432), die in einem positiven Winkel zu der Mittellinie
(35, 135, 435) auf einer ersten der entgegengesetzten Wände (47, 147, 447) geneigt
sind, und mit mindestens einer schwalbenschwanzförmigen Oberfläche (34, 134, 434),
die in einem negativen Winkel zu der Mittellinie (35, 135, 434) auf der zweiten (48,
148, 448) der entgegengesetzten Wände geneigt ist, wobei die erste Gruppe schwalbenschwanzförmiger
Oberflächen so zusammenwirkt, daß sie zusammenpassende Oberflächen eines zusammenwirkenden
Elements (10, 110, 210, 310, 410, 710) empfangen und mit diesem fest eingreifen, und
zwar aufgrund der relativen Bewegung des Verschleißelements in eine erste Längsrichtung,
wobei das zusammenwirkende Element an dem Verschleißteil (18) befestigt ist;
gekennzeichnet durch eine zweite Gruppe schwalbenschwanzförmiger Oberflächen (36,
37, 39, 136, 137, 139, 436, 437, 439) mit mindestens einer schwalbenschwanzförmigen
Oberfläche (36, 136, 436), die in einem negativen Winkel zu der Mittellinie (35, 135,
435) auf der ersten entgegengesetzten Wand (47, 147, 447) geneigt ist, und mit einem
Paar longitudinal beabstandeter schwalbenschwanzförmiger Oberflächen (37, 39, 137,
139, 437, 439), die in einem positiven Winkel zu der Mittellinie (35, 135, 435) auf
der zweiten entgegengesetzten Wand (48, 148, 448) geneigt sind, wobei die zweite Gruppe
schwalbenschwanzförmiger Oberflächen so zusammenwirkt, daß sie durch die relative
Bewegung in eine zweite Längsrichtung zusammenwirkende Oberflächen des zusammenwirkenden
Elements (10, 110, 210, 310, 410, 710) empfangen und fest mit diesen eingreifen.
2. Auswechselbares Verschleißelement (11, 111, 211, 311, 411, 711) nach Anspruch 1, wobei
jede entgegengesetzte Wand (47, 48, 147, 148, 447, 448) mindestens eine Kerbe (28,
43, 128, 143, 428, 443) aufweist, um einen Zugang des zusammenwirkenden Elements (10,
110, 210, 310, 410, 710) zwischen den entgegengesetzten Wänden (47, 48, 147, 148,
447, 448) zu ermöglichen.
3. Auswechselbares Verschleißelement (11, 111, 211, 311, 411, 711) nach Anspruch 2, wobei
jede Kerbe (28, 42, 128, 143, 428, 443) an beiden Längsenden durch eine der schwalbenschwanzförmigen
Oberflächen (30, 31, 36, 37, 130, 131, 136, 137, 430, 431, 436, 437) flankiert wird,
wobei jede einer Kerbe zugeordnete schwalbenschwanzförmige Oberfläche in Richtung
der Mittellinie (35, 135, 435) konvergiert, wobei sich die schwalbenschwanzförmige
Oberfläche von der Kerbe weg erstreckt.
4. Auswechselbares Verschleißelement (11, 111, 211, 711) nach Anspruch 1, wobei die genannte
erste Gruppe schwalbenschwanzförmiger Oberflächen ein Paar beabstandeter schwalbenschwanzförmiger
Oberflächen (31, 34, 131, 134) umfaßt, die in einem negativen Winkel zu der Mittellinie
(35, 135) auf der zweiten entgegengesetzten Wand (48, 148) geneigt sind, und wobei
die genannte zweite Gruppe schwalbenschwanzförmiger Oberflächen ein Paar beabstandeter
schwalbenschwanzförmiger Oberflächen (36, 38, 136, 138) umfaßt, die in einem negativen
Winkel zu der Mittellinie (35, 135) auf der ersten entgegengesetzten Wand (47, 147)
geneigt sind.
5. Auswechselbares Verschleißelement (311, 411) nach Anspruch 1, wobei die genannte schwalbenschwanzförmige
Oberfläche (434), die in einem negativen Winkel zu der Mittellinie (45) auf der zweiten
entgegengesetzten Wand (448) geneigt ist, longitudinal zwischen dem Paar schwalbenschwanzförmiger
Oberflächen (430, 432) positioniert ist, die in einem positiven Winkel zu der Mittellinie
(435) auf der ersten entgegengesetzten Wand (447) geneigt sind.
6. Auswechselbares Verschleißelement (311, 411) nach Anspruch 5, wobei die genannte schwalbenschwanzförmige
Oberfläche (436), die in einem negativen Winkel zu der Mittellinie (435) auf der ersten
entgegengesetzten Wand (447) geneigt ist, longitudinal zwischen dem Paar schwalbenschwanzförmiger
Oberflächen (437, 439) positioniert ist, die in einem positiven Winkel zu der Mittellinie
(435) auf der zweiten entgegengesetzten Wand (448) geneigt sind.
7. Auswechselbares Verschleißelement (511) zur Installation an einem Verschleißteil (518)
einer Konstruktion, die mit einem Abrasionsmaterial eingreifen kann, wobei das Element
folgendes umfaßt:
einen unitären, plattenartigen Körper mit Endwänden, Seitenwänden und oberen und unteren
Oberflächen, wobei eine der Oberflächen mit dem Abrastionsmaterial eingreifen kann,
wobei die andere Oberfläche der genannten oberen und unteren Oberflächen durch eine
Bewegung allgemein entlang der longitudinalen Mittellinie (535) gegenüber dem Verschleißteil
positioniert werden kann,
wobei die genannte andere Oberfläche neben beiden Seitenwänden mit transversal beabstandeten,
integralen, hervorstehenden Teilstücken (531, 542) ausgestattet ist, die einen zentralen
Schlitz mit entgegengesetzten Seitenwänden (547, 548) vorsehen,
wobei eine erste (547) der entgegengesetzten Wände ein Paar longitudinal beabstandeter
schwalbenschwanzförmiger Oberflächen (530, 532) aufeist, die in einem positiven Winkel
zu der Mittellinie (535) geneigt sind,
dadurch gekennzeichnet, daß die zweite (548) der genannten entgegengesetzten Wände
eine schwalbenschwanzförmige Oberfläche (548) aufweist, die allgemein parallel zu
der Mittellinie ist und die sich vollständig über die zweite entgegengesetzte Wand
erstreckt.
8. Auswechselbares Verschleißelement (311, 411) zur Installation an einem Verschleißteil
(18) einer Konstruktion, die mit Abrasionsmaterial eingreift, wobei das Element folgendes
umfaßt:
einen unitären, allgemein rechteckigen, plattenartigen Körper (312', 412') mit Endwänden
(313', 413', 314', 414'), Seitenwänden (315', 415', 316', 416') und oberen und unteren
Oberflächen (317', 417', 319', 419'), wobei eine der Oberflächen (319', 419') mit
dem Abrastionsmaterial eingreifen kann,
wobei die andere Oberfläche (317', 417') der genannten oberen und unteren Oberflächen
durch eine Bewegung allgemein entlang der longitudinalen Mittellinie (335, 435) gegenüber
dem Verschleißteil positioniert werden kann,
wobei die genannte andere Oberfläche (317', 417') neben beiden Seitenwänden (315',
415', 316', 416') mit transversal beabstandeten, integralen, hervorstehenden Teilstücken
(441, 442) ausgestattet ist, die einen zentralen Schlitz mit entgegengesetzten Seitenwänden
(447, 448) vorsehen,
wobei eine erste (447) der entgegengesetzten Wände ein Paar longitudinal beabstandeter
schwalbenschwanzförmiger Oberflächen (430, 432) aufweist, die in einem positiven Winkel
zu der Mittellinie (435) geneigt sind,
dadurch gekennzeichnet, daß die zweite (448) der genannten entgegengesetzten Wände
eine schwalbenschwanzförmige Oberfläche (434) aufweist, die in einem negativen Winkel
zu der Mittellinie geneigt ist und die allgemein zwischen den inneren Enden des ersten
entgegengesetzten Wandpaares schwalbenschwanzförmiger Oberflächen (430, 432) positioniert
ist, so daß ein zusammenwirkendes Element in dem Ende der Rille schief eingeführt
und danach geradegerichtet werden kann, um mit den schwalbenschwanzförmigen Oberflächen
zusammenzuwirken.
1. Elément d'usure remplaçable (11, 111, 211, 311, 411, 711) destiné à être monté sur
la partie (18) sujette à l'usure d'une structure qui peut être mise en contact avec
une matière abrasive, comprenant :
un corps unitaire, en forme de plaque, sensiblement rectangulaire (12', 412') ayant
des parois d'extrémité (13', 14', 313', 314', 413', 414'), des parois latérales (15',
16', 315', 316', 415', 416') et des surfaces supérieure et inférieure (17', 19', 317',
319', 417, '419'), une desdites surfaces (19', 319', 419') étant adaptée pour entrer
en contact avec la matière abrasive,
l'autre (17', 317', 417') desdites surfaces supérieure et inférieure étant adaptée
pour être positionnée en regard de ladite partie sujette à usure par un mouvement
dirigé généralement le long de son axe longitudinal (35, 135, 435),
ladite autre surface (17', 317', 417') adjacente aux deux parois latérales (15', 16',
315', 316', 415', 416') étant équipée de parties saillantes venues de matière, espacées
transversalement (41, 42, 141, 142, 441, 442) qui ménagent une fente centrale ayant
des parois opposées (47, 48, 147, 148, 447, 448),
un premier jeu de surfaces de queue d'aronde (30, 32, 34, 130, 132, 134, 430, 432,
434) comprenant une paire de surfaces de queue d'aronde (30, 32, 130, 132, 430, 432)
espacées longitudinalement, inclinées d'un angle positif par rapport audit axe (35,
135, 435) sur l'une desdites parois opposées (47, 147, 447) et au moins une surface
de queue d'aronde (34, 134, 434) inclinée d'un angle négatif par rapport audit axe
(35, 135, 435) sur la deuxième (48, 148, 448) desdites parois opposées, ledit premier
jeu de surfaces de queue d'aronde coopérant pour recevoir et attaquer solidement des
surfaces complémentaires d'un élément coopérant (10, 110, 210, 310, 410, 710) qui
est fixé à ladite partie sujette à l'usure (18) sous l'effet du mouvement relatif
dudit élément d'usure dans une première direction longitudinale,
caractérisé par un deuxième jeu de surfaces de queue d'aronde (36, 37, 39, 136,
137, 139, 436, 437, 439) comprenant au moins une surface de queue d'aronde (36, 136,
436) inclinée d'un angle négatif par rapport audit axe (35, 135, 435) sur ladite première
paroi opposée (47, 147, 447), et une paire de surfaces de queue d'aronde espacées
(37, 39, 137, 139, 437, 439) inclinées d'un angle positif par rapport audit axe (35,
135, 435) sur la deuxième paroi opposée (48, 148, 448), ledit deuxième jeu de surfaces
de queue d'aronde coopérant pour recevoir et attaquer solidement des surfaces complémentaires
de l'élément coopérant (10, 110, 210, 310, 410, 710) sous l'effet du mouvement relatif
dans une deuxième direction.
2. Elément d'usure remplaçable (11, 111, 211, 311, 411, 711) selon la revendication 1,
dans lequel chacune desdites parois opposées (47, 48, 147, 148, 447, 448) comprend
au moins une encoche (28, 43, 128, 143, 428, 443) destinée à permettre audit élément
coopérant (10, 110, 210, 310, 410, 710) de venir se placer entre lesdites parois opposées
(47, 48, 147, 148, 447, 448).
3. Elément d'usure remplaçable (11, 111, 211, 311, 411, 711) selon la revendication 2,
dans lequel chaque encoche (28, 43, 128, 143, 428, 443) est encadrée, à ses deux extrémités
longitudinales, par une desdites surfaces de queue d'aronde (30, 31, 36, 37, 130,
131, 136, 137, 430, 431, 436, 437), chacune desdites surfaces de queue d'aronde associée
à une encoche converge vers ledit axe (35, 135, 435) lorsque ladite surface de queue
d'aronde s'éloigne de ladite encoche.
4. Elément d'usure remplaçable (11, 111, 211, 711) selon la revendication 1, dans lequel
ledit premier jeu de surfaces de queue d'aronde comprend une paire de surfaces de
queue d'aronde (31, 34, 131, 134), inclinées d'un angle négatif par rapport audit
axe (35, 135) sur ladite deuxième paroi opposée (48, 148) et ledit deuxième jeu de
surfaces de queue d'aronde comprend une paire de surfaces de queue d'aronde espacées
(36, 38, 136, 138) inclinées d'un angle négatif par rapport audit axe (35, 135) sur
l'autre paroi opposée (47, 147).
5. Elément d'usure remplaçable (311, 411) selon la revendication 1, dans lequel ladite
surface de queue d'aronde (434) inclinée d'un angle négatif par rapport audit axe
(435) sur ladite deuxième paroi opposée (448) est positionné longitudinalement entre
ladite paire de surfaces de queue d'aronde (430, 432) inclinées d'un angle positif
par rapport audit axe (435) sur ladite première paroi opposée (447).
6. Elément d'usure remplaçable (311, 411) selon la revendication 5, dans lequel ladite
surface de queue d'aronde (436) inclinée d'un angle négatif par rapport audit axe
(435) sur ladite première paroi opposée (447) est positionnée longitudinalement entre
ladite paire de surfaces de queue d'aronde (437, 439) inclinées d'un angle positif
par rapport audit axe (435) sur ladite deuxième paroi opposée (448).
7. Elément d'usure remplaçable (511) destiné à être monté sur la partie (518) sujette
à l'usure d'une structure qui peut être mise en contact avec une matière abrasive,
comprenant :
un corps unitaire, en forme de plaque, sensiblement rectangulaire ayant des parois
d'extrémité, des parois latérales et des surfaces supérieure et inférieure, une desdites
surfaces étant adaptée pour entrer en contact avec ladite matière abrasive,
l'autre desdites surfaces supérieure et inférieure étant adaptée pour être positionnée
en regard de ladite partie sujette à usure par un mouvement dirigé généralement le
long de son axe longitudinal (535),
ladite autre surface adjacente aux deux parois latérales étant équipée de parties
saillantes venues de matière, espacées transversalement (541, 542) qui ménagent une
fente centrale ayant des parois opposées (547, 548),
une première (547) desdites parois opposées ayant une paire de surfaces de queue d'aronde
(530, 532) espacées longitudinalement d'un angle positif par rapport audit axe (535),
caractérisé en ce que la deuxième (548) desdites parois opposées présente une
surface de queue d'aronde (548) sensiblement parallèle audit axe et qui s'étend entièrement
en travers de ladite deuxième paroi opposée.
8. Elément d'usure remplaçable (311, 411) destiné à être monté sur la partie (18) sujette
à l'usure d'une structure qui peut être mise en contact avec une matière abrasive,
comprenant :
un corps unitaire, en forme de plaque, sensiblement rectangulaire (312', 412') ayant
des parois d'extrémité (313', 413', 314', 414'), des parois latérales (315', 415',
316', 416') et des surfaces supérieure et inférieure (317', 417, 319', 419'), une
desdites surfaces (319', 419') étant adaptée pour entrer en contact avec ladite matière
abrasive,
l'autre (317', 417') desdites surfaces supérieure et inférieure étant adaptée pour
être positionnée en regard de ladite partie sujette à usure par un mouvement dirigé
généralement le long de son axe longitudinal (335, 435),
ladite autre surface (317', 417') adjacente aux deux parois latérales (315', 415',
316', 416') étant équipée de parties saillantes venues de matière, espacées transversalement
(441, 442) qui ménagent une fente centrale ayant des parois opposées (447, 448),
une première (447) desdites parois opposées ayant une paire de surfaces de queue d'aronde
(430, 432) inclinées d'un angle positif par rapport audit axe (435),
caractérisé en ce que la deuxième (448) desdites parois opposées possède une surface
de queue d'aronde (434) inclinée d'un angle négatif par rapport audit axe et positionnée
sensiblement entre les extrémités intérieures de ladite paire de surfaces de queue
d'aronde (430, 432) de la première paroi opposée, pour permettre ainsi d'insérer obliquement
l'élément coopérant dans l'extrémité de la gorge puis de la redresser pour qu'elle
coopère avec lesdites surfaces de queue d'aronde.