Note: Descriptions are shown in the official language in which they were submitted.
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TITLE: TOOTH AND ADAPTOR ASSEMBLY
INVENTOR: NEIL DOUGLAS BENTLEY
TECHNICAL FIELD:
[0001] The present disclosure relates to excavating equipment, more
particularly, to bucket tooth and adaptor assemblies for use on dipper
buckets.
BACKGROUND:
[0002] Excavation in construction and mining applications is carried out more
efficiently when ground-engaging penetration attachments, such as tooth and
adaptor assemblies, are securely mounted on the leading digging edge of the
excavation dipper bucket and/or excavation equipment. Usually, adaptors are
rigidly attached to the bucket by either welding or some form of mechanical
fastener.
[0003] This chisel-like tooth of the assembly reduces the initial contact mass
of the bucket edge moving into the material being excavated by focusing the
accumulated digging forces at the leading edges of the tooth thereby
maximizing the penetration efficiency of the excavating equipment. The
loosened material can then be freely loaded into the excavation bucket or
simply diverted around the assembly when materials are only being broken
up. Abrasive grinding, multi-directional stresses and shock loading at
exceedingly high levels can continuously and abruptly breach the integrity of
the tooth and adaptor assembly during any given excavation application.
[0004] Canadian Patent 1,243,059 and US Patent 4,481,728 represented the
first generation elliptical tooth and adaptor system. This system demonstrated
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the use of a three-piece system in mining applications. This system enabled
the user to replace the primary consumable tooth separate from the fixed
carrier adaptor. Any number of consumable teeth could then be readily fitted
to the adaptor and replaced as each became worn out. Although this tooth
and adaptor system is functional, it requires certain installation and removal
techniques that are not desirable to use in the field. Some of this assembly's
shortcomings include the use of an oversized locking pin that incorporates
compressive elastomeric material vulcanized between two rigid members of
the locking pin. Excessive force has to be applied by a sledgehammer to
sufficiently compress the pin to permit full insertion into a smaller hole
that
received the lock pin. Installation and removal of the locking pin is also
time
consuming and physically difficult, particularly if the head of the pin became
flattened (mushroom shaped) from repeated hammer blows. This arduous
practice of changing out worn teeth and installing new teeth has eventually
become a safety concern. This original design is no longer acceptable to
maintenance workers in certain mining applications. In addition, several other
features of this design eventually became a concern.
[0005] Another problem with this type of tooth and adaptor system is the
physical properties of the vulcanized elastomeric material used to keep the
locking pin functional and maintain the tooth fully on the adaptor.
Deterioration of the elastomeric material is a common occurrence thereby
making the locking pin non reusable. In addition, the structural design of
this
tooth and adaptor system restricted the possibility of establishing a locking
system that would better preserve this important component.
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[0006] The extreme flowing pressures (several tons) of excavated materials
beneath the shovel bucket tend to force this type of locking pin upward and
out of the locked position. Occasionally, these pins are actually forced out
completely and allow the tooth to fall off.
[0007] Other defects of this tooth and adaptor system include its design of an
aligning common-through hole located centrally in both mated structural
members when the tooth was fully fitted to the adaptor to accept the locking
pin. The loss of structural mass in the tooth sidewalls weakened the tooth
and, occasionally, will break when subjected to severe digging applications.
[0008] In addition, the elastomeric material incorporated in the retainer pin
is
exposed to the chemical effects of the ore (i.e. tarsand) and this contributes
to
the premature breakdown of this material diminishing its ability to lock the
tooth to the adaptor. If the tooth should break or the retainer lock pin
becomes loose and falls out, the tooth and adaptor can uncouple, leaving the
less wear-resistant adaptor male mating nose exposed to harsh wear from the
continuing excavation process. In addition, any uncoupled or stray teeth can
severely damage process equipment downstream.
[0009] It is, therefore, desirable to provide a tooth and adaptor assembly for
a
dipper bucket that overcomes the shortcomings of the prior art described
above.
SUMMARY:
[0010] A tooth and adaptor assembly for a dipper bucket is provided. In some
embodiments, the assembly can comprise an adaptor having a front portion,
an intermediate portion and a rear portion. The rear portion can be configured
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for attaching to a dipper bucket as well known to those skilled in the art.
The
intermediate portion can extend between the front and rear portions and can
comprise a substantially circular base adjacent to the rear portion. In some
embodiments, the intermediate portion can taper or narrow in cross-section
from its base to the front portion. In some embodiments, the intermediate
portion can comprise an elliptical cross-section, and the front portion can
comprise a substantially flat front end. In some embodiments, at least one
sidewall of the intermediate portion can comprise a wedge portion extending
substantially perpendicular therefrom. In some embodiments, the adaptor can
further comprise at least one socket cavity disposed on the intermediate
portion configured to receive a leg extension disposed on the tooth, the leg
extension further comprising at least one inwardly pointing hook wherein a
retainer pin passageway is formed between the wedge portion and the at
least one inwardly pointing hook when the tooth is substantially seated on the
adaptor. When a retainer pin is inserted into the passageway, the bucket
tooth can be prevented from being removed from the adaptor.
[0011 ]The tooth can also comprise a front tip portion configured for
excavating and a rear portion extending from the front end. The rear portion
of the tooth can comprise a socket configured to accommodate the front and
intermediate portions of the adaptor in a coupled position. Specifically, the
socket can comprise an opening configured to mate with the base of the
intermediate portion and a bottom with a flat surface to mate with the front
portion of the adaptor. The socket can comprise an interior wall surface that
can be initially cylindrical at the entrance, and can then taper to the
bottom,
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the interior wall surface having a portion that is planar such that it can
mate
with the planar portion of the exterior surface of the intermediate portion of
the
adaptor.
[0012] In some embodiments, the adaptor front portion can comprise a
rectangular front end and enlarges in cross-section towards the substantially
circular base of the intermediate portion. The front and intermediate portions
can be configured to conform to an interior configuration of the tooth socket
so
as to prevent the tooth from rotating on the adaptor in the coupled position.
Accordingly, these additional mated-load bearing surfaces can keep the tooth
stable on the adaptor while a maintenance worker is changing out the tooth.
[0013] The complementary shapes of the front and intermediate portions of
the adaptor and the tooth socket can more effectively distribute the shock and
bearing loads throughout the assembly. The front and intermediate portions
can form multi-directional load-bearing surfaces so as to reduce the
possibility
of tooth and/or adaptor nose breakage.
[0014] Broadly stated, in some embodiments, an adaptor is provided for
releasably attaching a tooth to an excavation tool, said adaptor comprising: a
rear portion configured for attaching to an excavation tool; a front portion
configured for a sliding fit with a corresponding socket disposed on a tooth;
an
intermediate portion comprising an exterior surface and a base adjacent to the
rear portion, the intermediate portion narrowing in cross-sectional area from
the base to the front portion; a wedge portion extending from a sidewall
disposed on the intermediate portion; and a socket cavity disposed in the
sidewall near the wedge portion wherein a passageway is formed when a leg
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extension extending from the tooth is inserted into the socket cavity when the
tooth is seated on the adaptor, the passageway configured to receive a
retainer pin for releasably attaching the tooth to the adaptor.
[0015] Broadly stated, in some embodiments, a tooth is provided for
releasably attaching to an adaptor coupled to or mounted on an excavation
tool, the tooth comprising: a longitudinal body comprising a front tip portion
configured for excavating disposed on one end and a rear portion disposed on
an opposing end; a socket disposed on the rear portion, the socket
comprising a mouth, a side wall and an interior mating surface configured for
a sliding fit onto an exterior surface of an adaptor; and at least one leg
extension extending from the longitudinal body, the leg extension further
comprising at least one inwardly pointing hook.
[0016] Broadly stated, in some embodiments, a tooth and adaptor assembly is
provided for an excavation tool, the assembly comprising: an adaptor
comprising: a rear portion configured for attaching to an excavation tool, a
front portion configured for a sliding fit with a corresponding socket
disposed
on a tooth, an intermediate portion comprising an exterior surface and a base
adjacent to the rear portion, the intermediate portion narrowing in cross-
sectional area from the base to the front portion, a wedge portion extending
from a sidewall disposed on the intermediate portion, and a socket cavity
disposed in the sidewall near the wedge portion wherein a passageway is
formed when a leg extension extending from the tooth is inserted into the
socket cavity when the tooth is seated on the adaptor, the passageway
configured to receive a retainer pin for releasably attaching the tooth to the
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adaptor; and the tooth configured to releasably attach to the adaptor, the
tooth
comprising: a longitudinal body comprising a front tip portion configured for
excavating disposed on one end and a rear portion disposed on an opposing
end, a socket disposed on the rear portion, the socket comprising a mouth, a
side wall and an interior mating surface configured for a sliding fit onto an
exterior surface of an adaptor, and at least one leg extension extending from
the longitudinal body, the leg extension further comprising at least one
inwardly pointing hook.
BRIEF DESCRIPTION OF THE DRAWINGS:
[0017] Figure 1 is a perspective view depicting a tooth uncoupled from an
adaptor that is mounted to a dipper bucket.
[0018] Figure 2 is a perspective view depicting a tooth being seated on an
adaptor mounted to a dipper bucket.
[0019] Figure 3 is a side elevation view depicting the tooth and adaptor
assembly of Figure 1 with the tooth seated on the adaptor.
[0020] Figure 4 is a top plan view depicting the tooth and adaptor assembly of
Figure 3.
[0021] Figure 5 is a side elevation view depicting the tooth and adaptor
assembly of Figure 1 with the tooth uncoupled from the adaptor.
[0022] Figure 6 is a top plan view depicting the tooth and adaptor assembly of
Figure 5.
[0023] Figure 7 is a left side elevation view depicting the tooth and adaptor
assembly of Figure 3 showing the internal features of the coupled tooth and
adaptor in cross-hatch lines.
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[0024] Figure 8 is a top plan view depicting the tooth and adaptor assembly of
Figure 7.
[0025] Figure 9 is a close-up top plan view depicting the tooth and adaptor
assembly of Figure 8.
[0026] Figure 10 is a side elevation view depicting a retainer pin for use
with
the tooth and adaptor assembly of Figure 1.
[0027] Figure 11 is a cross-section side elevation view depicting a nut for
use
with the retainer pin of Figure 10.
[0028] Figure 12 is a cross-section front elevation view depicting the tooth
and
adaptor assembly of Figure 3 along section lines X1-X1.
[0029] Figure 13 is a cross-section front elevation view depicting the tooth
and
adaptor assembly of Figure 12 with a retainer pin installed.
[0030] Figure 14 is a cross-section front elevation view depicting the tooth
and
adaptor assembly of Figure 13 with a nut threaded to the retainer pin.
[0031) Figure 15 is a cross-section front elevation view depicting an
alternate
embodiment of the tooth and adaptor assembly of Figure 12.
DETAILED DESCRIPTION OF EMBODIMENTS:
[0032] Referring to Figures 1 and 2, an embodiment of a tooth and adaptor
assembly is shown. In some embodiments, tooth/adaptor assembly 5 can
comprise of excavation tooth 2, adaptor 3, retainer pin 1 and retainer pin nut
4. Adaptor 3 can comprise elongated U-shaped member 6 that can attach to
dipper bucket 7 on bucket lip 8, as well known to those skilled in the art.
Tooth 2 can be seated onto adaptor 3 and secured by retainer pin 1 that can
be installed into a retainer pin passageway formed when tooth 2 is seated on
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adaptor 3, and held in place by nut 4. Tooth 2 can be designed to bear the
brunt of the wearing forces caused by excavating and will wear out over time.
As tooth 2 wears out to the point that it is no longer serviceable, tooth 2
can
be removed from adaptor 3 by unthreading retainer pin 1 from retainer pin nut
4. Retainer pin 1 can then be removed from retainer pin passageway 9, as
illustrated in Figure 4. Tooth 2 can then be removed from adaptor 3.
[0033] Referring to Figures 3 and 4, side and top views of assembly 5 is
shown with tooth 2 fully seated on adaptor 3. In some embodiments, tooth 2
can comprise pointed tip 10 designed for excavating. As more clearly shown
in Figures 13 and 14, tooth 2 can be secured to adaptor 3 with retainer pin 1
seated in retainer pin passageway 9, and threaded into retainer pin nut 4.
[0034] Referring to Figures 5 and 6, side and top views of assembly 5 is
shown with tooth 2 uncoupled from adaptor 3. In some embodiments, adaptor
3 can comprise elliptical base portion 11 that can transition from elongated U-
shaped member 6 to intermediate circular tapered cone portion 12 and from
block portion 15. In some embodiments, block portion 15 can be rectangular
in cross-section, although other cross-sectional shapes can be used as well
known to those skilled in the art. In some embodiments, tapered cone portion
12 can comprise lug socket cavities 13 and 14, disposed on either side of
tapered cone portion 12. In some embodiments, lug socket cavities 13 and
14 can be a continuation of opposing planar surfaces 25 and 26 disposed on
the sides of tapered cone portion 12. In some embodiments, tooth 2 can
comprise opposing sidewall leg extensions 19 and 20 extending therefrom,
each comprising hooks 19a and 19b, and 20a and 20b, respectively, forming
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a groove therebetween. To couple tooth 2 to adaptor 3, tooth 2 can comprise
socket 16 that is configured to receive front block portion 15, tapered cone
portion 12 and elliptical base portion 11. Wedge portions 32 and 33 disposed
on planar surfaces 25 and 26, respectively, can be configured to slide in the
grooves defined by the hooks disposed on leg extensions 19 and 20. Load
forces passing from adaptor 3 to tooth 2, and from tooth 2 back to adaptor 3,
can be transmitted via the uniform mated surfaces disposed on tooth 2 and
adaptor 3. In some embodiments, when tooth 2 is substantially seated on
adaptor 3, retainer pin passageway 9 can be formed to provide a substantially
vertical and continuous passageway for receiving retainer pin 1, as
illustrated
in Figures 8 and 9.
[0035] Referring to Figures 7 and 8, Figure 7 illustrates an internal cross-
section view of tooth 2 coupled on adaptor 3. Figure 8 illustrates an internal
cross-section top view of tooth 2 coupled on adaptor 3.
[0036] Tooth sidewalls 17a to 17d (in some embodiments, socket 16 can
comprise a rectangular cross-section, with each sidewall disposed therein
labelled as 17a through d, respectively) and primary thrust bearing surface 18
can provide an opening to receive front block 15 of adaptor 3 in a sliding
fit.
In some embodiments, tooth socket 16 can comprise tapered, elliptical and
planar surfaces configured to substantially and uniformly mate to elliptical
base portion 11, tapered cone portion 12 and front block 15. Tooth sidewall
leg extensions 19 and 20 can uniformly seat into socket cavities 13 and 14,
respectively, in a sliding fit.
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[0037] Figure 9 illustrates an enlarged top view of one embodiment of tooth
and adaptor assembly 5, wherein retainer pin passageway 9 is formed when
tooth 2 is fully seated on adaptor 3. In some embodiments, top surface 27 of
passageway 9 can be formed by the combination of tooth sidewall leg
extension 20, stepland 24 and leg hook 20a, as shown in Figures 9 and 12.
[0038] Referring to Figure 10, one embodiment of retainer pin 1 is shown. In
some embodiments, retainer pin 1 can comprise cylindrical body 22 with
flanged head bolt head 21 disposed at an upper end thereof, and threaded
end 23 disposed at a lower end thereof. Referring to Figure 11, a cross-
section view of one embodiment of threaded nut 4 is shown.
[0039] Referring to Figures 12 to 14, a cross-section view of tooth and
adaptor
assembly 5, as shown in Figure 3, is illustrated. In Figure 12, retainer pin 1
is
shown about to be inserted in passageway 9. In Figure 13, retainer pin 1 is
inserted in passageway 9, wherein retainer pin 1 is adjacent to hooks 20a and
20b of leg extension 20 and positioned behind wedge portion 32, as shown in
Figure 9. In this configuration, retainer pin 1 prevents tooth 2 from being
removed from adaptor 3. In Figure 14, retainer pin nut 4 is shown threaded
onto threaded end 23 of retainer pin 1 to secure it to tooth and adaptor
assembly 5.
[0040] In Figure 15, an alternate embodiment of tooth 2 is shown seated on
adaptor 3. In this embodiment, tooth 2 can comprise threaded hole 34
integrated therein to receive threaded end 23 of retainer pin 1.
[0041] Although a few preferred embodiments have been shown and
described, it will be appreciated by those skilled in the art that various
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changes and modifications might be made without departing from the scope
of the invention. The terms and expressions used in the preceding
specification have been used herein as terms of description and not of
limitation, and there is no intention in the use of such terms and expressions
of excluding equivalents of the features shown and described or portions
thereof, it being recognized that the invention is defined and limited only by
the claims that follow.
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