U.S. patent application number 11/278163 was filed with the patent office on 2007-04-19 for tooth and adaptor assembly for a dipper bucket.
This patent application is currently assigned to Amsco Cast Products (Canada) Inc.. Invention is credited to Neil Douglas Bentley.
Application Number | 20070084094 11/278163 |
Document ID | / |
Family ID | 37913461 |
Filed Date | 2007-04-19 |
United States Patent
Application |
20070084094 |
Kind Code |
A1 |
Bentley; Neil Douglas |
April 19, 2007 |
Tooth and adaptor assembly for a dipper bucket
Abstract
A tooth and adaptor assembly is provided for a dipper bucket.
The assembly includes an adaptor having a rear portion for
attaching to a dipper bucket, a tooth capable of releasable
attachment to the adaptor and a retainer pin for securing the tooth
to the adaptor. The adaptor has a tapered intermediate portion that
narrows to a rectangular front portion and a planar surface on a
portion of its intermediate portion. A groove traverses the planar
surface, and extends perpendicular to the horizontal longitudinal
axis of the adaptor. The tooth has a tip at its front end for
digging and a socket at its rear end that is configured to receive
the front and intermediate portions of the adaptor. When the tooth
is coupled to the adaptor, an opening on the rear end of the tooth
aligns with the groove to define a passageway that terminates
within the socket of the tooth. The retainer pin is inserted into
the passageway to secure the tooth to the adaptor and complete the
assembly.
Inventors: |
Bentley; Neil Douglas;
(Edmonton, CA) |
Correspondence
Address: |
DENNIS T. GRIGGS
17950 PRESTON ROAD
SUITE 1000
DALLAS
TX
75252
US
|
Assignee: |
Amsco Cast Products (Canada)
Inc.
Edmonton
CA
|
Family ID: |
37913461 |
Appl. No.: |
11/278163 |
Filed: |
March 31, 2006 |
Current U.S.
Class: |
37/452 |
Current CPC
Class: |
E02F 9/2833 20130101;
E02F 9/2825 20130101; E02F 9/2841 20130101 |
Class at
Publication: |
037/452 |
International
Class: |
E02F 9/28 20060101
E02F009/28 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 14, 2005 |
CA |
2,523,513 |
Claims
1. A tooth and adaptor assembly for a dipper bucket, comprising: a)
an adaptor comprising: i) a rear portion adapted for attaching to a
dipper bucket; ii) a front portion having a substantially flat
front end, and iii) a tapered intermediate portion having an
exterior surface and a substantially circular base adjacent to said
rear portion, said intermediate portion narrowing in
cross-sectional area towards said front portion, said intermediate
portion further comprising a substantially planar surface on a
portion of its exterior surface and a groove traversing said planar
surface, said groove substantially perpendicular to a longitudinal
axis passing through the center of said front, intermediate and
rear portions; b) a tooth having a front tip portion adapted for
excavating and an enlarged rear portion having a top surface, said
enlarged rear portion forming a socket adapted to complement said
front and intermediate portions of said adaptor, said socket having
an entrance that is substantially circular to mate with the base of
said intermediate portion, a bottom with a substantially flat
surface to mate with the flat front end of said front portion and a
tapered interior wall surface narrowing from said entrance to said
bottom, a portion of said interior wall surface being substantially
planar to mate with the planar surface portion of said intermediate
portion whereby said tooth fits securely on said adaptor and
engages substantially the entire outer surface of said front and
intermediate portions of said adaptor, said tooth further
comprising an opening on said enlarged rear portion that
substantially aligns with said groove to define a passageway when
said tooth is substantially engaged with said adaptor; and c) a
retainer pin adapted to be inserted through said opening into said
passageway to secure said tooth to said adaptor.
2. The assembly as set forth in claim 1 wherein said bottom of said
socket and said front portion of said adaptor are rectangular in
cross-section and are adapted to couple together in sliding
fit.
3. The assembly as set forth in claim 1 wherein said enlarged rear
portion of said tooth further comprises a raised deflector
extending around at least a portion of said opening for deflecting
debris away from said passageway and retainer pin.
4. The assembly as set forth in claim 1 wherein said planar surface
portion of said intermediate portion is offset from a vertical axis
sloping inwardly from top to bottom on said intermediate
portion.
5. The assembly as set forth in claim 4 wherein said retainer pin
comprises a body conforming to the shape of said passageway and an
enlarged head with a bottom surface adapted to cover said opening
and mate with said top surface so as to prevent debris from
entering said passageway.
6. The assembly as set forth in claim 5 wherein said retainer pin
further comprises a biasing element that compresses into said
retainer pin as it is driven into said passageway, said biasing
element extending outwardly into a complementary recess when said
retainer pin is fully inserted in said passageway.
7. The assembly as set forth in claim 6 wherein said retainer pin
further comprises a magnet to urge said retainer pin downwardly in
a latched position within said passageway.
8. The assembly as set forth in claim 5 wherein said retainer pin
further comprises a prying element on said enlarged head for prying
said retainer pin out of said passageway.
9. The assembly as set forth in claim 5 wherein said retainer pin
further comprises at least one hole disposed through said body for
containing a lubricant.
10. The assembly as set forth in claim 1 wherein said passageway is
rectangular in cross section and is further configured to receive
said retainer pin therein.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to excavating equipment, and
more particularly to an adaptor and tooth assembly for a dipper
bucket.
BACKGROUND OF THE INVENTION
[0002] Excavation practice in construction and mining applications
is often most efficiently carried out when ground engaging,
penetration attachments (tooth and adaptor assemblies) are securely
mounted on the leading digging edge of the excavation dipper bucket
and/or excavation equipment. Usually, the adaptor(s) are rigidly
attached by either welding or some form of mechanical
fastener(s).
[0003] This chisel-like assembly reduces the initial contact mass
of the bucket edge moving into the material(s) being excavated by
focusing the accumulated digging forces at the leading tooth
point(s); thereby, maximizing the penetration efficiency of the
excavating equipment. The loosened material(s) can then be freely
loaded into the excavation bucket or diverted around the assembly
when only break-up excavation is the prime motive. Abrasive
grinding, multi-directional stresses and shock loading at
exceedingly high levels can continuously and abruptly assault the
integrity of the tooth and adaptor assembly during any given
excavation application.
[0004] Canadian Patent 1,243,059 and U.S. Pat. No. 4,481,728
represented the first generation elliptical tooth and adaptor
system. This system demonstrated the user 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.
[0005] Although the prior art disclosing the first generation
elliptical tooth and adaptor system was functional, this system
required certain installation and removal techniques that reduced
its use in the field. Some of the shortcomings of this prior art
include the use of an oversized locking pin that incorporated
compressive elastomeric material vulcanized between two rigid
members of the locking pin. Excessive force had 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 was also time consuming
and physically difficult, particularly if the head of the pin
became flattened (mushroom shaped) from repeated hammer blows. The
arduous practice of changing out worn teeth and installing new
teeth eventually became 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.
[0006] The first generation elliptical locking pin was dependent
upon the physical properties of the vulcanized elastomeric material
to carry out its required job of maintaining the tooth fully on the
adaptor. Deterioration of the elastomeric material was a common
occurrence and the structural design of this tooth and adaptor
system restricted the possibility of establishing a preferred
locking system not so depended on this component. This type of
locking pin was not reusable.
[0007] Extreme flowing pressures (several tons) of excavated
materials beneath the shovel bucket tended to force the original
style of lock pin upward and out of the locked position.
Occasionally, these pins would actually be forced completely out
and the tooth would fall off.
[0008] The first generation elliptical system was designed with an
aligning common through hole located centrally in both mated
structural members when the tooth was fully fitted to the adaptor.
The resulting aligned through holes formed an opening to accept the
locking pin. The loss of structural mass in the tooth sidewalls
weakened this component, and occasionally, the tooth would break
when subjected to severe digging applications.
[0009] The first generation elliptical system was designed with the
tooth not being completely stable while resting on the adaptor and
without the lock pin installed. If a maintenance worker
unintentionally bumped an unlocked tooth, it could easily slide
off, resulting in an injury to the worker.
[0010] Other prior art based on the above-noted system had gaps on
the assembled tooth and adaptor, and within and around the lock
pinholes. This condition can leave the mating fit surfaces of the
assembly, the lock pin bearing support surfaces and its related
structural members vulnerable to the extreme flowing pressures
(several tons) of excavated materials that are readily forced into
these gaps. The abrasive qualities of the ore, combined with any
movement between the assembled components during the excavation
process create an aggressive grinding effect that deteriorates
these important dimensional load-bearing surfaces. The resulting
wear can contribute to a "loose fit" condition affecting all three
assembled components. This condition is especially true when
certain "self-lubricated" and highly abrasive ores such as tar sand
are being excavated. These ores have the inherent ability to
quickly enter all gaps and internal aspects of the mated assembly.
If the retainer lock pin does become 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.
[0011] It is, therefore, desirable to have a tooth and adaptor
assembly for a dipper bucket that overcomes the shortcomings of the
prior art described above.
SUMMARY OF THE INVENTION
[0012] The present invention is a tooth and adaptor assembly for a
dipper bucket. In a representative embodiment, the assembly
comprises an adaptor having a front portion, an intermediate
portion and a rear portion. The rear portion is adapted for
attaching to a dipper bucket as well known to those skilled in the
art. The intermediate portion extends between the front and rear
portions and has a substantially circular base adjacent to the rear
portion. The intermediate portion tapers or narrows in
cross-section from its base to the front portion. Preferably, the
intermediate portion has an elliptical cross-section. The front
portion has a substantially flat front end. The exterior surface of
the intermediate portion has a portion of its surface that is
substantially planar thereby making the intermediate portion
roughly D-shaped in cross-section. A groove is disposed along the
planar surface, the groove being perpendicular to a longitudinal
axis passing through the center of the front, intermediate and rear
portions. Preferably, the groove is rectangular in
cross-section.
[0013] The assembly also comprises a tooth having a front tip
portion adapted for excavating and an enlarged rear portion
extending from the front end. The enlarged rear portion comprises a
top surface and a socket configured to accommodate the front and
intermediate portions of the adaptor in a coupled position.
Specifically, the socket has an opening adapted to mate with the
base of the intermediate portion and a bottom with a flat surface
to mate with the front portion. The socket has an interior wall
surface that is initially cylindrical at the entrance and then
tapers to the bottom, the interior wall surface having a portion
that is planar such that it mates with the exterior surface of the
intermediate portion of the adaptor. The enlarged rear portion of
the tooth also has an opening, which is offset to one side on the
top surface. The opening is in alignment with the adaptor groove
when the tooth is fully seated on the adaptor thereby defining a
passageway that extends from the top surface and terminates within
the entrance of the tooth socket. A retainer pin inserted into the
passageway and driven downwardly towards a "home" latched position
secures the tooth on the adaptor. The retainer pin can be removed
by urging it upwardly out of the passageway.
[0014] Accordingly, the present invention relates to an assembly of
three interlocking components--a tooth, an adaptor and retainer
pin. The present invention may be characterized by the elements as
set forth below.
[0015] In one embodiment, the present invention utilizes an offset,
substantially vertical retainer pin whereby installation and
removal of the retainer pin is performed from the top surface of
the tooth. There is no bottom through-hole necessary in the bottom
of the tooth to "drift" the retainer pin out in order to
disassemble the tooth from the adaptor. This design prevents entry
of highly pressurized compaction forces from beneath that can force
the typical base exposed retainer pin(s) upward and out of their
latched position.
[0016] In another embodiment, the present invention provides an
enclosed assembly comprising three components including a tooth, an
adaptor and a retainer pin. The components are configured in such a
way that the mated surfaces of the assembled components minimize
debris from entering certain areas of the coupled and latched tooth
and adaptor assembly. In another representative embodiment, the
retainer pin has an enlarged head with a bottom surface having a
beveled seating collar completely around and beneath the head. The
head is adapted to cover the entirety of the retainer pin opening
and to mate with the tooth top surface so as to prevent debris from
entering the passageway. The head of the retainer pin does have
some exposure to falling excavated debris that can assist in
maintaining the retainer pin in its "home" latched position.
[0017] In another representative embodiment, the adaptor front
portion has a rectangular front end and enlarges in cross-section
towards the substantially circular base of the intermediate
portion. The intermediate portion incorporates a 3/4 round
cylindrical shank having a flat side surface containing the groove,
which is formed thereon. The front and intermediate portions are
adapted 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, the tooth remains stable on the
adaptor while the maintenance worker is performing the tooth
change-out. The possibility of the unlatched tooth sliding off the
adaptor is virtually eliminated and this makes for safer working
conditions.
[0018] In view of the complementary shapes of the front and
intermediate portions of the adaptor and the tooth socket, the
shock and bearing loads are more effectively distributed throughout
the assembly. The front and intermediate portions form
multi-directional load-bearing surfaces so as to reduce the
possibility of tooth and/or adaptor nose breakage. The cylindrical
shank also complements the overall load carrying capabilities of
the assembly and the physical mass of the shank more than
compensates for the loss of structural material given up to the
groove that forms the passageway for the retainer pin.
[0019] The tooth and adaptor assembly of the present invention
provides additional thrust-load bearing capacity with respect to
forward directional movement of the assembly mounted on the
excavation bucket and/or equipment. In particular, the present
invention minimizes the amount of displacement that can occur
between the tooth and the adaptor thereby reducing undesirable
movement of the retainer pin within the passageway.
[0020] It is an object of the present invention to provide a tooth
and adaptor assembly for a dipper bucket that is easily serviced.
The tooth and adaptor assembly may be disassembled and reassembled
with ease, without the need for excessive force applied by
sledgehammers or the like. The retainer pin may be moderately
tapped into the passageway formed when the tooth is fully seated on
the adaptor to the "home" latched position with an ordinary machine
hammer. A typical pry bar, or a similar tool, can easily remove the
retainer lock-pin from its "home" latched position. One of the
advantages of the retainer pin of the present invention is that it
is not dependent on an elastomeric material to supports its primary
function of keeping latched and maintaining the coupled position of
the tooth on the adaptor. Accordingly, the retainer pin may be
reused over the course of several tooth change outs, if
necessary.
[0021] Broadly stated, one aspect of the present invention is a
tooth and adaptor assembly for a dipper bucket, comprising: an
adaptor comprising a rear portion adapted for attaching to a dipper
bucket, a front portion having a substantially flat front end, and
a tapered intermediate portion having an exterior surface and a
substantially circular base adjacent to said rear portion, said
intermediate portion narrowing in cross-sectional area towards said
front portion, said intermediate portion further comprising a
substantially planar surface on a portion of its exterior surface
and a groove traversing said planar surface, said groove
substantially perpendicular to a longitudinal axis passing through
the center of said front, intermediate and rear portions; a tooth
having a front tip portion adapted for excavating and an enlarged
rear portion having a top surface, said enlarged rear portion
forming a socket adapted to complement said front and intermediate
portions of said adaptor, said socket having an entrance that is
substantially circular to mate with the base of said intermediate
portion, a bottom with a substantially flat surface to mate with
the flat front end of said front portion and a tapered interior
wall surface narrowing from said entrance to said bottom, a portion
of said interior wall surface being substantially planar to mate
with the planar surface portion of said intermediate portion
whereby said tooth fits securely on said adaptor and engages
substantially the entire outer surface of said front and
intermediate portions of said adaptor, said tooth further
comprising an opening on said enlarged rear portion that
substantially aligns with said groove to define a passageway when
said tooth is substantially engaged with said adaptor; and a
retainer pin adapted to be inserted through said opening into said
passageway to secure said tooth to said adaptor.
[0022] Other objects, features and advantages of the present
invention will become clear from the following detailed
description, when read in associated with the drawings and the
appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a perspective view of an embodiment of the present
invention showing the tooth uncoupled from the adaptor that is
mounted to a dipper bucket.
[0024] FIG. 2 is a perspective view of an embodiment of the present
invention showing the tooth being seated on the adaptor and secured
with the retainer pin.
[0025] FIG. 3 is a side elevational view of an embodiment of the
present invention showing the tooth coupled to the adaptor and
secured with the retainer pin.
[0026] FIG. 4 is a top plan view of an embodiment of the present
invention showing the tooth coupled to the adaptor and secured with
the retainer pin.
[0027] FIG. 5 is a side elevational view of an embodiment of the
present invention showing the tooth and the adaptor in an uncoupled
position.
[0028] FIG. 6 is a top plan view of an embodiment of the present
invention showing the tooth and the adaptor in an uncoupled
position.
[0029] FIG. 7 is a side elevational cross-section view of the tooth
in accordance with an embodiment of the present invention shown
along sections lines A-A.
[0030] FIG. 8 is a side elevational cross-section view of the tooth
in accordance with an embodiment of the present invention shown
along section lines B-B.
[0031] FIG. 9 is a top plan cross-sectional view of the tooth in
accordance with an embodiment of the present invention shown along
section lines C-C.
[0032] FIG. 10 is a side elevational view of the adaptor in
accordance with an embodiment of the present invention.
[0033] FIG. 11 is a top plan view of the adaptor in accordance with
an embodiment of the present invention.
[0034] FIG. 12 is a front elevational view of the retainer pin in
accordance with an embodiment of the present invention.
[0035] FIG. 13 is a right side elevational view of the retainer pin
in accordance with an embodiment of the present invention.
[0036] FIG. 14 is a front elevational cross-section view of an
embodiment of the present invention shown along section lines
D-D.
[0037] FIG. 15 a front elevational cross-section view of the
retainer pin in accordance with an embodiment of the present
invention as shown within section line E.
DETAILED DESCRIPTION OF THE INVENTION
[0038] Referring to FIGS. 1 and 2, a representative embodiment of
the present invention is shown. Tooth/adaptor assembly 10 broadly
consists of excavation tooth 12, adaptor 14 and retainer pin 16.
Adaptor 14 comprises an elongated U-shaped member that attaches to
dipper bucket 18 on bucket lip 19 as well known to those skilled in
the art. Tooth 12 is seated onto adaptor 14 and secured by retainer
pin 16 that is inserted through opening 20 to fit snugly into
groove 22. Tooth 12 is designed to bear the brunt of the wearing
forces caused by excavating and will wear out over time. As tooth
12 wears out to the point that it is no longer serviceable, tooth
12 can be removed from adaptor 14 by extracting retainer pin 16
from opening 20 and sliding tooth 12 off of adaptor 14 so that a
new tooth 12 may be installed.
[0039] Referring to FIGS. 3 and 4, side and top views of assembly
10 is shown with tooth 12 fully seated on adaptor 14. Tooth 12 has
a pointed top 24 designed for excavating is shown secured to
adaptor 14 with retainer pin 16 seated in opening 20. In a
preferred embodiment, tooth 12 comprises a raised deflector 26 that
is positioned at least partially around opening 20. Deflector 26
is, preferably, L-shaped and acts to prevent debris from thrusting
directly against the top of retainer pin 16 during excavation
operations.
[0040] Referring to FIGS. 5 and 6, side and top views of assembly
10 is shown with tooth 12 uncoupled from adaptor 14. Adaptor 14
comprises base portion 28 that is generally circular in
cross-section, intermediate elliptical tapered cone portion 38 and
front block portion 59. Disposed on a side of base and intermediate
portions 28 and 38 is flat surface 32 that gives base portion 28
and intermediate portion 38 a generally D-shaped or 3/4 round
cross-section. Flat surface 32 has a planar axis that is tilted
off-vertical as it slopes inwardly from top to bottom on adaptor
14. Traversing across flat surface 32 is groove 22 that is,
preferably, substantially perpendicular to longitudinal axis 11 of
assembly 10. To couple tooth 12 and adaptor 14 together, tooth 12
comprises socket 34 that receives front, intermediate and base
portions 59, 38 and 28 of adaptor 14. When tooth 12 is seated on
adaptor 14, thrust bearing surface 36 of tooth 12 contacts thrust
bearing surface 30 of adaptor 14. Load forces passing from adaptor
14 to tooth 12 and from tooth 12 back to adaptor 14 are transmitted
via these uniform mated fit surfaces. Furthermore, when tooth 12 is
seated on adaptor 14, opening 20 aligns with groove 22 to provide a
substantially continuous passageway 21 for receiving retainer pin
16.
[0041] In FIGS. 7 and 8, side cross-sectional views of tooth 12 are
shown. FIG. 9 illustrates a top plan cross-sectional view of tooth
12. Tooth 12 comprises socket-opening 34 that has a substantially
circular interior load bearing surface 40 to match base 28 of
adaptor 14. Transition cavity 46 is a relief groove that separates
load surface 40 from elliptical cone surface 42. Transition cavity
44 is another relief groove that separates elliptical cone surface
42 from block sidewalls 50a to 50d. Relief cavities 44 and 46 are
relatively rectangular in shape and offers additional relief
clearance for adaptor transition zone edges 37 and 39 on tooth 12
when it is fully seated on adaptor 14.
[0042] Referring to FIG. 9, sidewalls 50a to 50d and primary thrust
bearing surface 48 provide an opening to receive front block 59 of
adaptor 14 in a sliding fit. Preferably, front block 59 and the
opening defined by sidewalls 50a to 50d are rectangular. Cone
surface 42 and circular base 40 further comprises flat surface 52
that gives this intermediate portion of socket 34 a generally
D-shaped or 3/4 round cross-section. Groove 54 traverses planar
surface 52 and is generally perpendicular to the horizontal axis of
tooth 12. Groove 54 comprises sidewalls 55a to 55c and aligns with
groove 22 on tooth 12 to provide the substantially continuous
passageway 21 for receiving retainer pin 16. Sidewall 55a serves as
a flat bearing surface to accept moderate thrust loads from
retainer pin 16 during excavation operations. At the bottom of
groove 54 is mitre surface 56 that marks the end of passageway 21.
In a representative embodiment of the present invention, passageway
21 is rectangular in cross-section.
[0043] Referring to FIGS. 10 and 11, side and top views of adaptor
14 are shown, respectively. Adaptor 14 comprises of adaptor base
28, which is generally circular, elliptical body 38 and front block
59. Front block 59 is preferably, rectangular and comprises of
sidewalls 60a to 60d and primary thrust surface 58. Elliptical body
38 tapers from transition 37 to transition 39. Offset flat surface
32 is disposed on elliptical body 38 and adaptor base 28. Groove 22
is disposed on flat surface 32 and is generally perpendicular to
the horizontal axis of adaptor 14. Groove 22 aligns with groove 54
of tooth 12 when tooth 12 is fully seated onto adaptor 14. Front
block 59 is adapted for a sliding fit with the bottom of socket 34
which is defined by sidewalls 50a to 50d and thrust bearing surface
48. Preferably, adaptor front block 59 has a generally rectangular
cross section, with flat front mating surface 58 having a width
that is greater than its height, that is, top and bottom mating
surfaces 60a and 60c wider than flat side mating surface 60b and
60d.
[0044] Front and side views of retainer pin 16 are shown in FIGS.
12 and 13. Retainer pin 16 comprises sidewalls 64a and 64d, bottom
mitre surface 68, pin head 62 and lift lug 66. In a representative
embodiment, pin head 16 has a bottom surface adapted to cover the
entirety of opening 20 and mate with the top surface of tooth 12 so
as to prevent debris from entering passageway 21. In a
representative embodiment, pin head 62 further comprises of
bevelled edges 76 that uniformly mate with the edges of opening 20.
This uniform metal-to-metal surface contact is maintained by the
downward magnetic pull, as described below, that encloses
passageway 21 and the interior of assembly 10. Positioned on bottom
surface 68 is magnet 70. Magnet 70 urges retainer pin 16 into
passageway 21 as magnet 70 is attracted to groove bottom surface
56. To further keep retainer pin 16 within passageway 21, sidewall
64d further comprises spring-loaded plunger 72 that latches into
complementary recess 78 in passageway 21. In a representative
embodiment of the present invention, plunger 72 is a setscrew.
Lubrication holes 74 disposed transversely through the body of
retainer pin 16 retain lubricant that reduces wear from potential
thrust loads applied to retainer pin 16 during excavation
operations. To remove retainer pin 16 from passageway 21, a pry bar
or tool is used to pry up on lift lug 66 on pin head 62. Retainer
pin 16 is of a rigid construction and may be manufactured from
steel or alloys having suitable strength and wear properties.
[0045] In FIGS. 14 and 15, front cross-sectional views of assembly
10 are shown. When retainer pin 16 is inserted into passageway 21,
plunger 72 compresses into the body of retainer pin 16 and bottom
surface 68 and magnet 70 contact bottom surface 56 in socket 34.
Once retainer pin 16 is fully inserted into passageway, plunger 72
extends into recess 78 defined by the transition between adaptor
base 28 and load bearing surface 40 of tooth 12. Accordingly,
retainer pin 16 is held in position by magnet 70 contacting bottom
surface 56 and plunger 72 extending into recess 78. The downward
magnetic pull derived from magnet 70 assists in keeping retaining
pin 16 fully seated and stabilized in passageway 21. Retainer pin
16 is marginally smaller than opening 20 and is readily received in
sliding fit within passageway 21. Passageway 21 permits full
insertion of retainer pin 16 therein and bottom mitre surface 68
bottoms out on groove bottom surface 56. All internal surfaces of
passageway 21 can transfer varying thrust loads via retainer lock
pin external sidewalls 64a to 64d while retainer pin 16 securely
maintains the fully coupled position of tooth 12 on adaptor 14
during excavation operations.
[0046] Although a few preferred embodiments have been shown and
described, it will be appreciated by those skilled in the art that
various 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 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
* * * * *