Note: Descriptions are shown in the official language in which they were submitted.
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A ripper boot including a male carrier and a replaceable female tooth
The present invention relates to an improved ripper boot and, in particular,
to a
ripper boot having a male carrier portion for engaging a replaceable female
tooth or
cap having a high tensile tip. The ripper boot of the present invention is
suitable for
use in a range of applications involving the ripping or cleaving of extremely
hard
material.
BACKGROUND OF THE INVENTION
The present inventor is the owner of a number of co-pending patent
applications relating to ripper boot improvements, including Australian
Letters Patent
No. 2006284527 relating to a ripper boot having a replaceable ripping tooth.
The
ripping tooth includes a shank having tapered sides adapted to be press fit
into a
correspondingly shaped cavity in the boot so that it is fixed during operation
for
improved performance and reduced wear and tear.
This invention is useful in any application where extremely hard and abrasive
rock is to be excavated, for example, in the extraction of precious stones
such as opal
typically achieved using a standard bulldozer ripper boot, or in heavier duty
operations which require excavators and the like. In each of these
environments, the
ripper boot teeth, loader bucket teeth, etc, need to be strong and wear
resistant enough
to work the hard rock. Conventional ripper boots tend to break, and apply
extremely
high loads on machinery.
Conventional ripper boots consist of predominantly two sections, a carrier
section for attachment to machinery, for example, to a bulldozer tyne or
loader bucket
shank, and a tooth section which is typically integrally associated with the
carrier
section via a weld. In the applicant's abovementioned patent, it is proposed
that the
tooth section be made replaceable. More particularly, the proposed tooth
section
includes a shank having tapered sides being fixable within a correspondingly
shaped
cavity associated with the carrier section by way of an interference fit.
Although very successful in its operation, the present Applicant has
recognised
the need for a still further improved replaceable tooth. There is a need for a
boot and
replaceable tooth combination which addresses issues such as particles
becoming
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clogged in the space between the tooth shank and the carrier cavity, and
difficulties in
removing the replaceable tooth after use. One reason this occurs is that the
gap
between the tooth head portion and the carrier section is adjacent the tip of
the boot
and is inclined to receive particles therein. In the case of the Applicant's
prior art
apparatus, because this gap is "upstream" of the taper locked walls, as the
ripper boot
moves through ground particles are inclined to enter between the walls via the
gap.
The result is that the tooth can become caked inside the socket to an extent
where it
can no longer be removed.
It is therefore an object of the present invention to overcome at least some
of
the aforementioned problems or to provide the public with a useful
alternative.
SUMMARY OF THE INVENTION
Therefore in one form of the invention there is proposed a ripper boot
characterised
by:
a carrier adapted for connection to a shank of a vehicle;
a locking tapered male projection associated with a tip of said carrier;
a replaceable ripping cap including a substantially conical outer shape
terminating in a tip of
high tensile material, said cap further including a locking tapered bore to
mate with said
locking tapered male projection such that said cap is non-rotatably secured on
said ripper boot
carrier by way of locking interference fit such that during use said
replaceable ripping cap
does not rotate and said locking interference fit prevents particulate matter
from entering
between walls of said cap and said male projection.
Preferably said locking tapered male projection is inwardly tapered such that
its cross
sectional dimension is less at the tip of the carrier, said locking tapered
bore having a
corresponding inward taper.
In preference said cap is removable from the male projection when said taper
lock is
broken.
In preference the cross section of the male projection and the cap bore is
square.
Alternatively the cross section of the male projection and the cap bore is
circular.
Preferably the carrier includes a central longitudinal axis.
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In preference said male projection and engaged cap extend along said
longitudinal
axis such that the angle of attack is greater than the angle of the surface
being worked.
Alternatively said male projection is constructed to extend at an angle
upwards from
said carrier longitudinal axis such that the angle of attack of the engaged
cap is substantially
parallel with the angle of the surface being worked.
Preferably said angle of attack is between zero and ninety degrees upwards
from the
longitudinal axis of the carrier.
In preference said angle of attack is between zero and ten degrees upwards
from the
longitudinal axis of the carrier.
Advantageously, and when applied to most standard dozers, the angle of attack
should be approximately six degrees upwards from the longitudinal axis of the
carrier.
Preferably the male projection and the cap include transverse channels
extending
there through which become co-axially aligned when the projection is engaged
within said
cap bore, to allow for insertion of a retaining pin.
In preference said high tensile tip is constructed at least partially of
tungsten metal.
In a further form of the invention said carrier includes two or more male
projections
adapted to engage two or more removeable caps.
In a still further form of the invention there is proposed a ripper boot
characterised
by:
a carrier including a male projection at a working end thereof;
a replaceable ripping cap including an associated socket;
said replaceable ripping cap being secured to said carrier by way of an
interference fit so that
during use said replaceable ripping cap does not rotate;
said interference fit prevents particulate matter from entering between walls
of said cap and
said associated socket;
said male projection has a tapered wall;
said cap has a tapered socket to mate with said tapered wall; and wherein:
said cap has a substantially conical outer shape and terminates in a tip
constructed at least
partially of high tensile material;
said cap and said carrier engage by a mating relationship between said socket
and said
correspondingly shaped male projection, said socket and male projection being
inwardly
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tapered to thereby establish a taper lock between the carrier and cap, said
cap being
removable from the carrier when said taper lock is broken.
Preferably said ripper boot further includes retaining means for retaining
said cap on
said carrier.
In preference said retaining means is in the form of a retaining pin, the
carrier
projection and cap including transverse channels extending there through which
become co-
axially aligned when the cap is fully engaged on said male projection, to
allow for insertion of
said retaining pin.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part
of this specification, illustrate several implementations of the invention
and, together
with the description, serve to explain the advantages and principles of the
invention.
In the drawings:
Figure 1 illustrates a rear view of a ripper boot in accordance with the
present
invention;
Figure 2 illustrates a front view of the ripper boot of Figure 1;
Figure 3 illustrates a top view of the ripper boot of Figure 1;
Figure 4 illustrates a side view of the ripper boot of Figure 1;
Figure 5 illustrates a side cross-sectional view of the ripper boot of Figure
1;
Figure 6 illustrates an exploded perspective view of the ripper boot of Figure
1;
Figure 7 illustrates a cross-sectional view of a ripper boot in accordance
with a
second embodiment of the present invention;
Figure 8 illustrates an exploded perspective view of the ripper boot of Figure
7;
Figure 9 illustrates a cross-sectional view of a ripper boot in accordance
with a
third embodiment of the present invention; and
Figure 10 illustrates an exploded perspective view of the ripper boot of
Figure 9.
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DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following detailed description of the invention refers to the accompanying
drawings. Although the description includes exemplary embodiments, other
embodiments are possible, and changes may be made to the embodiments described
5 without departing from the spirit and scope of the invention. Wherever
possible, the
same reference numbers will be used throughout the drawings and the following
description to refer to the same and like parts.
The present invention relates to an improved ripper boot according to three
different embodiments 10a, I Ob and I Oc. The ripper boot I Oa is illustrated
in Figures
1-6, ripper boot 10b in Figures 7-8, and ripper boot 10c in Figures 9-10. For
the
purpose of brevity, the first ripper boot 10a will be described in full detail
and any like
parts found in the other embodiments will not be described again and will be
referred
to using like numbers.
Figures 1-6 illustrate the ripper boot 10a of the present invention which
includes a carrier 14 and a replaceable ripping tooth or cap 16. In operation,
the
carrier 14 is placed over and conformed to fit with a ripper boot tyne of a
bulldozer
(not shown) or other earth moving machinery.
The carrier 14 is held in place by utilisation of a pair of oppositely
positioned
retaining holes 20 located in the rear hollow portion 22 of the carrier 14
which, in
conjunction with a retaining pin (not shown), is designed to attach the
carrier 14 of the
ripper boot 10a to the available tyne 18. It is to be understood that the
carrier 14 may
be conformed to fit any available ripper boot shank, and that any desired
attachment
means other than the retaining pin 24 and oppositely positioned retaining
holes 20
may be used.
The ripper boot carrier 14 also includes a substantially solid portion 26 at
its
front. This solid portion 26 provides mass and assists in the ripping process
to some
degree, and also provides a male projection 28 which in the embodiment shown
is
shaped substantially like a four-sided pyramid having a sawn-off apex. The
base of
the male projection 28 is of a lesser dimension to that of the solid portion,
and so an
inward shoulder is defined there around. The inward shoulder includes a kink
on two
opposed sides, however, this is not essential to achieving engagement between
the
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two members but rather for facilitating assembly as will be explained in more
detail
below.
The replaceable ripping tooth 16 is made up of a head portion 30 and a female
body 32. Primarily, the female body 32 provides a female socket or bore 34.
The bore
34 includes longitudinal walls that taper outwardly and which are conformed to
fit
over the male projection 28 of the carrier 14.
The projection 28 of the carrier 14 is thus correspondingly shaped with the
female socket 34 of the tooth 16, and allows the projection 28 to be fixedly
secured
within the female socket 34 by way of an interference fit, otherwise known as
a taper
lock. As those skilled in the art would realise, an interference fit is
extremely strong
and will not permit any rotation of the replaceable ripping tooth 16, even if
say the
side walls had a circular cross section. In preference, the socket 34 is cast
so as to
ensure that its internal dimensions correspond with those of the male
projection 28.
One of the benefits of the present invention is that the taper locked walls
are
less inclined to receive small particles of rock, including clay fines, which
are a
known cause of irrevocably locking the male and female portions together. This
is
because the engaging walls are located "upstream" of the gap between the
carrier and
the tooth sections, that is, inside the ripping tooth as opposed to inside the
carrier 14.
Because of the forward cleaving action of the boot 10, and the configuration
of the
tooth 16, it is unlikely that fines will enter the gap between the base of the
tooth body
32 and the solid portion 26 of the carrier 14 and then travel forwards between
the
taper locked side walls. Thus, even after extensive use, the tooth 16 should
still be
easily removable and replaceable, without having to remove the carrier 14 from
the
dozer.
Once the tooth is fixed onto the projection 28, the head portion 30 extends
longitudinally outwards from the boot. The head portion 30 of the tooth is
designed
as a conical structure which does not to extend too far outwards from the
carrier 14 so
as to ensure it is not damaged or broken off during the ripping process. The
head
portion 30 can be made of high tensile strength material, such as tungsten for
example. A high tensile tip ensures that even the hardest rock may be
penetrated and
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that problems associated with existing ripper boot tips which become easily
worn are
minimised.
It is to be understood that the ripper boot 10 of the present invention is not
limited in its use and may be used in association with a wide variety of
machinery
including small to large bulldozer rippers, end cutting bits on dozer blades,
dragline
buckets, bucket dredges, excavators, and loader bucket teeth. In some of these
larger
operations, the present invention becomes particularly effective because of
the labour
and cost involved in the need to replace such heavy pieces of equipment from
the
machinery, and instead just having to replace an easily removeable, lighter
weight
cap.
In cases where the tooth may become prone to rust, for example in
applications where the tolerances between the tooth and the projection are not
required to be so tight, it is envisaged that the projection 26 and/or tooth
16 can be
coated with a suitable rust-proof coating.
In order to ensure that the replaceable ripping tooth 16 is always fixed
within
the carrier 14 during use, a secondary locking means may also be used,
preferably in
the form of a retaining pin 36. The ripper boot 10 embodied in Figures 1-6
includes
such a retaining pin 36. The projection 28 includes a groove 38 extending
transversely
across a lower side thereof such that when it is fully inserted into socket
34, the
groove 38 becomes co-axially aligned with an aperture 40 which extends
transversely
through the body 32 of the tooth 16. Once aligned, the retaining pin 36 may
simply be
inserted through the aligned holes to lock the tooth in place.
It is to be understood that the groove 38 need not extend all the way through
the projection, but may for example only extend halfway, in which case the
locking
pin 36 would be half of the length shown, and an aperture 40 would only need
to be
present through one face of the tooth body 32.
It is envisaged that an interference fit is adequate in maintaining the tooth
fixed within the socket, but a secondary locking means such as the locking pin
may be
used if required. The pin may be of the compressible type whereby prior to
insertion,
its cross section must be compressed so that following insertion it expands to
provide
a tighter fit.
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As mentioned earlier, the carrier includes a shoulder with a kink on only two
opposed walls adapted to act as a locating means and receive correspondingly
shaped
walls of the cap. The skilled addressee would realise that this will assist
the assembler
in placing the cap over the male projection in the correct orientation and
ensuring the
apertures line up. In the embodiment shown, the apertures 38 in the cap are in
the
extended walls which are received in the kinks. It is to be understood that
the present
invention does not require any means of orientation assistance for placement
of the
cap over the male projection, and that if one is used, it need not necessarily
be limited
to that shown in the embodiment and described herein.
Removal of the ripping tooth 16 from the carrier 12 may be accomplished by
simply breaking the taper lock between the engaging walls using any suitable
prying
tool.
It is to be understood that the configuration of the ripping tooth 16 may
vary.
In this case, the head 30 is a conical head, however, it could equally well be
a conical-
type head having a double inward taper rather than just a single taper angle.
Furthermore, as mentioned earlier, the cross-sectional shape of the projection
28 and
socket 34 need not be square but may be any other shape such as triangular or
circular, provided an interference fit is still achievable.
The second embodiment of the invention is illustrated in Figures 7-8 and
relates to a ripper boot 10b which has the same interference fit tooth 16 as
described
above, but which includes an alternate angle of attack. In having an upwardly
angled
solid portion 26 and projection 28, those skilled in the art will appreciate
that the
ripping tooth 16 once fitted onto the projection will also be angled with
respect to the
carrier 14.
The angle of the solid portion 26 is shown in the drawings to be quite
substantial for the purpose of clarity, however, through experimentation it
has been
found that an angle of approximately 6 degrees from the longitudinal axis of
the
carrier body is optimal. At this angle, the outer surface of the ripping tooth
becomes
aligned approximately parallel with the layers of rock being cleaved. These
layers are
typically, but not always, parallel with the ground surface. Existing ripper
boots,
including ripper boot 10a, may be modified to include the features of ripper
boot 10b.
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It has been found that when the tooth is positioned at this angle, the boot
may
cleave through the ground more efficiently than hitherto known ripper boot
arrangements resulting in benefits such as reduced chatter, reduced wear and
tear on
the tooth, and reduced load on the bulldozer. It is to be understood that the
angle at
which the solid portion 26 and projection 28 extend with respect to the
carrier 14 may
be made to vary depending on the required operation.
A raised angle of attack could equally well be achieved by having a solid
portion 26 and projection 28 extending longitudinally with respect to the
carrier 12, as
was the case in the ripper boot 10a of the first embodiment, but with socket
34 cast at
a predetermined angle inside the tooth 16 so that the ripping tooth 16 may
extend
outwards therefrom at that angle.
Figures 9-10 illustrate a ripper boot 10c according to a third aspect of the
invention. Rather than having a single socket arrangement, the tooth 50
includes two
sockets for receiving two projections of the carrier 14. There are two head
portions 52
and 54 associated with the tooth 50. Such a configuration may be suitable in a
number
of different applications including in excavator loader buckets which require
a
plurality of teeth for their operation. For example, a single loader bucket
may include
a single shank portion (not shown) for attachment thereto of a single carrier
section
having a plurality of associated tooth sections. As already mentioned, the
present
invention is not intended to be limited to any one of these configurations.
Further advantages and improvements may very well be made to the present
invention 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 limited to the details
disclosed herein but
is to be accorded the full scope of the claims so as to embrace any and all
equivalent
devices and apparatus.
