Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02636939 2008-07-07
A Si:RFACF. ENGAGING TOOL INCLUDING HiGfi TENSILI; INSERTS
The present invention relates to surface engaging tools and, in panicular, to
the use of
high tensitc inserts which are braze welded to the tip ur contact edge of such
touls for
increasing their strength and lifespan making them particularly suitable for
use when
excavating extrentely hard rock.
BACKGRL)UNI] OF THE INVENrTION
The present inventor is the owner of a number af co-pending patent
appiications
including PCTIAU2006d0012I8 and AU20069D4612, relating to ripper boot
irnprovements,
for particular use witli bulldozers used to excavate hard rock to iocate
precious steutes such as
opal. In ptnicuiar, the inventor has been in volved in improving the wear
resistwtce of such
boots by using replaceable high teasile tips, improving their mounting meuns
within the boot,
as well as altering their angle of attack.
The inventor has realised that the use of high tensile tips such as tungsten
need not be
limited to ripper boots unly, and that such matcrial could be used in other
smail to large scale
surface engaging equipntent. A problem to date has been in attaching and
securing high
tensile material to the tip or alung the contact edge of such tools. As those
skilled in the art
would realise, surface engaging tools are typically made of steel and
therefore welding of any
material to a tip or end thereof w=ill cause weakening of the surrounding
tnetal, and under
heavy impact conditions, the tool becomes prone to fracture at these weak
spota. Tror this
reason, the use of welded on high tensile tips on such tools has not been
adapted in the wear
parts industry.
It is therefore an object of !he present invention to overcome this problem or
to at
least ptovide the public with a useful alternative.
It is a iurther object of the present invcntion to provide a surface engaging
tool
capable of engaging extremely hard grnund through use of at least one high
tensile insert
welded to a contact surf.ice thereof.
SUMMARY OF TI;L- INVENTIO\I
Therefore in one ti>rm of the Invention there is proposed a surface engaging
tool
comprising: 30 a rigid hKnly including at least one edge adapted to eontact
surface during use; and
at ieast one slot lining said contact edge; and
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a high tensilc insert adaptixl to be tixedly engaged within each slot to
thereby improve the
strCrtgth characteristics of the tool.
Preferably said insert includes at least a portion which is correspondingly
shaped with
said slot for engagement therewith.
In preference said insert is of a frusto-triangular shape including a head
which
prcxrudes a short distance outwardly fmm said contact edge.
Preferably said tool includes a plurality of inserts spaced apart equally
along the
cont.act edge of the tool.
Pneterablv each insert is braze welded into the slot.
In preference subsequent to wclding the inscrt into said slot, thc tool is
heut treated.
E'referably the toul is tempered until the required physical propenies of the
metal surratnding
the welded areas are regained.
Advantageously said high tensile material is tungsten metal.
In prefcrencG aaid tuul is in the form of a ripper baot of the type adapted to
be
mounted to a shank of a bulldozer or like equipment, said ripper bout
including a carrier
means adapted to connect said ripper boot to said shank.
Alternatively said tool is in the form of a bulldozer blade or a grader blade.
BRIEF DESCRZPTiON OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a pan of
this
specifeation, illustraic several implcmentuticros uf the invention and,
together with the
description, serve to explain the advantages and principles of the invention.
In tho drawings-
rigurt 1 illustrates a front perspective view of a ripper hoot including high
tensile
inserts aloug its contact edge, in accordance with the present inventioa:
FiguPe 2 illustrates an exploded perspective view of the ripper boot of Figure
l;
Figure 3 illustratcs a side cross sectional view of the ripper boot of Figure
l;
Figure 4 illustrates a front perspectivc view uf an altematc ripper boot
including high
tensile inserts aiong its contact cdge;
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Figure 5 illustrates a front perspective view of a grader blade including high
tensile
inserts along its contact edge; and
Figure 6 illustrates a front perspective view of a bulldozer blade inclttding
high tensile
inserts along its contact edge.
1)E,Sf'1tlPT1QN OF THE P'REFERR$D F.Nff3Oi)IIVIFNTS
The following detailcd description of the inventiun refers to the
accotnpanying
drawings. Aithough the de.criptiun includes exemplary embodiruents, other
embodiments
are poasible, and changes may be made to the embodiments described without
departing from
the spirit and scope of the invent~on. Wherey-er possible, the same referenco
nurnbcrs will bo
used throughout the drawings and the following deseription to refer to thc
sanie and likc pwrts.
The present invention relates to ground engaging tools 10 having high tensilc
inserts
12 welded along a contact edge 14 thereof. Reference to a "contact edge"
herein refers in
most cases to an edge of the tool which is the tirst to contact the ground or
surface.
Iigures 1-3 illustrate the invention when applied to ripper boots 10a, Figure
4
illustrates the invention when applied to an alternate ripper boot M. Figtue S
illustrates the
invcntion when applied to a grader blade lOc, and Figtue 6 illustrates ahG
invention when
applied to a bulldozer blade I Od. It is to be understood that the invention
could equally wcll
be applied to any other ground engaging tool, or any tool requiring high
tensile contacl edges.
Referring firstly to Figures 1-3, the ripper bixk I Oa includes a carrier
section 16
which is hollm- and conformed to fit over a ripper boot tyne (not shown), and
a solid
engaging section 18 which includes a contact edge 14. Four slots 20 line the
edge 14 and un:
shapcd to receive high tensile inserts 12 which are preferably secured therein
by brnnze
welding so that they protrude slightly nutwandly from the contact edgc 14.
This is to ensurc
that the high tensilc material, prcfcrably tungsten, is the first material
that contacts the surface
to be broken up during operation of the boot. The result is a surfac:e
engaging tool of superior
strength characteristics and which may be used to rip through extremely hard
surfaces, for
example, such a tooi would be suitable in the ripping of hard sandstone.
According to the embodiments shown, each insert 12 is of a fnisto-triangular
shape
having a rectanguiar cross-sectiun along its height, the insett being welded
to Ute tool so that
the head of th.e frusto-triangle is directed outwardly. ft ls to he understood
that the shape of
the inserts are not to be limited to frusto-triangular. The shape of the
insert can be altered to
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suit the tool, or the application. For example, it may he that in some
environments, a rounded
or pointed head is mre suitabte.
'I'he carrier section 16 is typically held in place by utiiisation of a pair
of co-axially
aligned retaining holes 22 and 24 located in opposed side walls 26 and 28 of
the carrier
section 12 respectively. A retaining pin (not shown) is adapted to extend
through the holes 22
and 24 and through an aperture (not shown) associated with the available tyne.
It is to be
understood that the carrier 12 may he conformed to fit any available ripper
boot or loader
bucket shank, and that the present immttion is nnt intended to be limited to
only this form of
attachment.
Figure 4 illustrates an altemate ripper boot I Ob including substantially the
same
features as ripper boot 10a, except it is thinner and only accommodates two
inserts 12 at a tip
therrof. Figure 5 illustrates a conventional grader blade I Oc comprising a
longitudinal Wdy
26 that is curved along its height. The grader blade I Oc is typically
associawd with a powLred
machinc (not shown) which drivcs the blade, and includes a bottom edge 28
attached to the
body 26 by bolts 30, and used to gradc or level a ground surface. It is this
bottom edge 28 that
inclttdes a plurality of welded on high tensile inserts 12. A conventional
bulldozer blade I Od
is shown in 1~'ip re 6, and similarty, a plurality of high tensile inserts 12
lines the lower edge
32 of the blade lOd. The blade IUe in this ca4e comprises a longitudinal tray-
type body 34 for
storing the ground or rubble that has been ripped through contact with edge
32, also bolted to
the body 34 using bolts 36. Again, althaugh not shown, the blade l0d is
adapted to be moved
by a human-operated powered machine.
In order for the tools 10 to maintain their intended physical properties
at'ter welding,
they tnay need to be subjeoted to t'urther heat tn:atrncnt. Those skilled in
the att would realise
that welding the inserts 12 in place causes the surrounding metal to heat up
and thereby lose
some of its important physical properties which ettablc it to withstand strong
impact. FLrrther
heat lrratntenl.such as LGmpering is thereftxe required to prevent fracture of
the metal at weak
spots surrounding the welds. The preferred welding mcthod is brttze or bronze
welding which
involves the depositing of a filler metal 38 such as bronze into the joint
between the slot and
the insert.
In io far as the ditnensions of the insarts are concenied, it is cstitnated
that for ripper
boots, they shuuld be within the range of one fifteenth to one tenth the
length of the boot. For
example, for a ripper boot that is approximately 30cm long, the inserts should
be
approxintately 2-3cm. An inserr. that is 3cm long would have a+uidth of
approximately 4mm.
The number of inserts shuuld be prolxrrlionai to the desired .r=trength
characteristies of the
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tooi, In gencral, for a ripper buot having a contact edge of approximately 8em
for example,
four inserts could be used which are spaced apart by approximately (cm, as
shown in Figure
1.
The prrsent invention therefore provides fnr an improved tool of the type used
to
engage and penetrate hard surfaces, in particular hard surfaces which would
otherwise
damage or decrease the lifespan of conventional wear patis. The tool may be in
the f<nnt of a
ripper boot, a bulldozer blade, a grader blade, or other siniilar equipnient,
and achieves this by
having one or ntore higlr tensile inserts welded to a tip or along a first
contact edge there(if.
Those skilled in the art would reaGse the benefit of being able to inerease
thc efficicncy and
lifespan of wear parts bv including tungsten or high tensile material inserts,
particularly in the
mining industry in which wear parts ntay require replacement every few hours.
Furthermore,
less maintenance is required on the carrying tool during operation which means
that the
associated machinery does not need to idle so often, saving considerable tinie
and expense.
Further advantages and improvemcnts may very w=cll be niade to the present
inve-ntion without deviating from its scope. Although the invention has been
shown and
described in what is conceived to be the most practical and preferred
embodiment, it is
recognized that departures may be made therefrom within the scope and spirit
of the
invention, which is not to be linutod to the details disclosed herein but is
to be accorded the
full scope of the clai ms so as to embrace any and all equivalent devices and
apparatus.
In any claims that follow and in the summary of the invention, except w=hene
the context requires otherwise due to express lAaguagc or tx:cessary
implication, the
word "comprising" is used in the sense of "including", i.e. the features
specified may
be associuted with ftuther features in various embodiments of the invention,
