U.S. patent application number 11/726267 was filed with the patent office on 2008-01-03 for tooth and adaptor assembly.
This patent application is currently assigned to Amsco Cast Products (CANADA) Inc.. Invention is credited to Neil Douglas Bentley.
Application Number | 20080000114 11/726267 |
Document ID | / |
Family ID | 38834891 |
Filed Date | 2008-01-03 |
United States Patent
Application |
20080000114 |
Kind Code |
A1 |
Bentley; Neil Douglas |
January 3, 2008 |
Tooth and adaptor assembly
Abstract
A tooth and adaptor assembly for a dipper bucket includes an
adaptor having a rear portion for attaching to the dipper bucket, a
tooth capable of releasable attachment to the adaptor and a
retainer pin for securing the tooth to the adaptor. The adaptor
further includes a tapering intermediate portion that narrows to a
rectangular front portion. The adaptor further includes a planar
surface on a portion of its intermediate portion and a cavity on
the planar surface for receiving the retainer pin. The tooth has a
tip at its front end for digging and a socket at its rear end
configured to receive the front and intermediate portions of the
adaptor. A small opening on the rear end of the tooth aligns with
the cavity when the tooth is seated on the adaptor. The retainer
pin is urged outward of the cavity by a biasing element to engage
the small opening on the tooth so as to secure the tooth to the
adaptor.
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: |
38834891 |
Appl. No.: |
11/726267 |
Filed: |
March 21, 2007 |
Current U.S.
Class: |
37/457 |
Current CPC
Class: |
E02F 9/2858 20130101;
E02F 9/2866 20130101; E02F 9/2833 20130101 |
Class at
Publication: |
37/457 |
International
Class: |
E02F 9/28 20060101
E02F009/28 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 28, 2006 |
CA |
CA 2551312 |
Claims
1. An adaptor for releasably attaching a bucket tooth to an
excavation tool, the adaptor comprising: a) a rear portion adapted
for attaching to an excavation tool; b) a front portion adapted for
a sliding fit with a corresponding socket disposed on a bucket
tooth; c) an intermediate portion comprising an exterior surface
and a base adjacent to the rear portion, the intermediate portion
narrowing a cross-sectional area from the base to front portion; d)
a substantially planar surface disposed on a portion of the
exterior surface; and e) a passageway extending from the planar
surface at least partially into the adaptor, the passageway adapted
to receive a retainer pin for releasably attaching the bucket tooth
to the adaptor.
2. The adaptor as set forth in claim 1 wherein the excavation tool
is a tool selected from the group comprising a dipper bucket, a
front-end loader bucket, a mining shovel bucket, an excavator
bucket, a bucket wheel trencher, a chain trencher or a dredging
cutterhead.
3. The adaptor as set forth in claim 1 wherein the rear portion is
U-shaped and adapted to attach to a lip of an excavation tool.
4. The adaptor as set forth in claim 1 wherein the front portion
comprises a key having a substantially flat front end.
5. The adaptor as set forth in claim 1 wherein the front portion
comprises a key having a substantially flat front end and the flat
front end is disposed substantially perpendicular to a longitudinal
axis of the adaptor.
6. The adaptor as set forth in claim 1 wherein the front portion
comprises a key having a substantially flat front end and the key
has a cross-sectional area that is polygon-shaped.
7. The adaptor as set forth in claim 1 wherein the front portion
comprises a key having a substantially flat front end and the key
has a cross-sectional area in the form of a polygon selected from
the group comprising a triangle, a square, a rectangle, a rhombus,
a trapezoid, a pentagon, a hexagon, a heptagon or an octagon.
8. The adaptor as set forth in claim 1 wherein the front portion
comprises a key having a substantially flat front end and the key
has a cross-sectional area in the form of an ellipse.
9. The adaptor as set forth in claim 1 wherein the base is
substantially circular in cross-section.
10. The adaptor as set forth in claim 1 wherein the front portion
comprises a key having a substantially flat front end and the
intermediate portion is cone-shaped between the base and the
key.
11. The adaptor as set forth in claim 1 wherein the front portion
comprises a key having a substantially flat front end, the
intermediate portion is elliptical in cross-section and the key is
rectangular in cross-section.
12. The adaptor as set forth in claim 1 wherein the front portion
comprises a key having a substantially flat front end and the
substantially flat front end is disposed substantially
perpendicular to a longitudinal axis of the adaptor.
13. The adaptor as set forth in claim 1 wherein the front portion
comprises a key having a substantially flat front end and the
substantially flat front end comprises a planar surface that is
disposed substantially vertical relative to a longitudinal axis of
the adaptor.
14. The adaptor as set forth in claim 1 wherein the front portion
comprises a key having a substantially flat front end and the
substantially flat front end comprises a planar surface that is
disposed substantially in parallel with a longitudinal axis of the
adaptor.
15. The adaptor as set forth in claim 1 wherein the front portion
comprises a key having a substantially flat front end, the
substantially flat front comprises a planar surface and the
passageway is disposed substantially perpendicular to the planar
surface.
16. The adaptor as set forth in claim 1 wherein the passageway is
approximately rectangular in cross-section.
17. The adaptor as set forth in claim 1 wherein the passageway is
approximately square in cross-section.
18. The adaptor as set forth in claim 1 wherein the passageway
comprises rounded corners.
19. The adaptor as set forth in claim 1 wherein the passageway is
approximately circular in cross-section.
20. The adaptor as set forth in claim 1 wherein the base further
comprises at least one stabilizing lug adapted to mate with at
least one positioning slot disposed on the bucket tooth when the
bucket tooth is substantially seated on the adaptor.
21. A bucket tooth for releasably attaching to an adaptor attached
to an excavation tool, the bucket tooth comprising: a) a
longitudinal body comprising a front tip portion adapted for
excavating disposed on one end and a rear portion disposed on an
opposing end; b) a socket disposed on the rear portion, the socket
comprising a mouth, a side wall and an interior mating surface
adapted for a sliding fit onto an exterior surface of an adaptor;
c) a substantially planar surface disposed on a portion of the
interior mating surface; d) an aperture disposed on the planar
surface, the aperture adapted to substantially align with a
passageway disposed on the adaptor; and e) a catch disposed on the
planar surface between the mouth and the aperture, the catch
adapted to secure a retainer pin disposed in the passageway to the
aperture, the retainer pin comprising a biasing element adapted to
urge the retainer pin to engage the aperture when the tooth is
substantially seated on the adaptor thereby preventing the tooth
from being removed from the adaptor.
22. The bucket tooth as set forth in claim 21 wherein the
excavation tool is a tool selected from the group comprising a
dipper bucket, a front-end loader bucket, a mining shovel bucket,
an excavator bucket, a bucket wheel trencher, a chain trencher and
a dredging cutterhead.
23. The bucket tooth as set forth in claim 21 wherein the socket
narrows in cross-sectional area from the mouth to a bottom key-way
that substantially corresponds to a front portion of the
adaptor.
24. The bucket tooth as set forth in claim 21 wherein the socket
narrows in cross-sectional area from the mouth to a bottom key-way
and the bottom key-way comprises a bottom flat surface that is
substantially perpendicular to the longitudinal body.
25. The bucket tooth as set forth in claim 21 wherein the socket
narrows in cross-sectional area from the mouth to a bottom key-way
and the bottom key-way has a cross-sectional area that is
polygon-shaped in profile.
26. The bucket tooth as set forth in claim 25 wherein the polygon
is selected from the group comprising a triangle, a square,a
rectangle, a rhombus, a trapezoid, a pentagon, a hexagon, a
heptagon and an octagon.
27. The bucket tooth as set forth in claim 21 wherein the socket
narrows in cross-sectional area from the mouth to a bottom key-way
and the bottom key-way has a cross-sectional area that is
elliptically shaped in profile.
28. The bucket tooth as set forth in claim 21 wherein the socket
narrows in cross-sectional area from the mouth to a bottom key-way
and the bottom key-way has a cross-sectional area that is circular
in profile.
29. The bucket tooth as set forth in claim 21 wherein the socket
defines a cone-shaped opening as it narrows from the mouth to a
bottom key-way.
30. The bucket tooth as set forth in claim 29 wherein the
cone-shaped is elliptical in cross-section and the bottom key-way
is rectangular in cross-section.
31. The bucket tooth as set forth in claim 29 wherein the bottom
key-way comprises a bottom flat surface that is substantially
perpendicular to the longitudinal body.
32. The bucket tooth as set forth in claim 21 wherein the front
portion comprises a key having a substantially flat front end and
the substantially flat front end comprises a planar surface that is
disposed substantially vertical relative to a longitudinal axis of
the adaptor.
33. The bucket tooth as set forth in claim 21 wherein the front
portion comprises a key having a substantially flat front end, the
substantially flat front comprises a planar surface and the
passageway is disposed substantially perpendicular to the planar
surface.
34. The bucket tooth as set forth in claim 21 wherein the catch is
a ramp that compresses the biasing element of the retainer pin when
the retainer pin slides along the ramp as the tooth is seated onto
the adaptor until the retainer pin is urged into the aperture by
the biasing element thereby securing the tooth to the adaptor.
35. The bucket tooth as set forth in claim 34 wherein the aperture
is a frusto-conical opening.
36. The bucket tooth as set forth in claim 21 wherein the aperture
extends through the side wall to an exterior side of the
longitudinal body to provide communication to the retainer pin
whereby a tool can be inserted into the aperture and engage the
retainer pin to compress the biasing element and allow the retainer
pin to clear the catch thereby enabling the tooth to be removed
from the adaptor.
37. The bucket tooth as set forth in claim 21 wherein the socket
further comprises at least one positioning slot adapted to mate
with at least one stabilizing lug disposed on the adaptor when the
bucket tooth is substantially seated on the adaptor.
38. A retainer pin adapted for releasably attaching a bucket tooth
to an adaptor, the tooth comprising a socket having an interior
surface and adapted for sliding fit on to the adaptor, the retainer
pin comprising: a) a longitudinal body having first and second
ends, the body being adapted for insertion into a passageway
disposed on an adaptor; b) a biasing element disposed on the first
end; and c) the second end adapted to seat in an aperture disposed
on a socket interior surface of a bucket tooth when the retainer
pin is inserted first end first into the passageway of the adaptor
thereby retaining the tooth on the adaptor once the tooth is
substantially seated on the adaptor.
39. The retainer pin as set forth in claim 38 wherein the second
end is further adapted to slide along a ramped catch disposed on
the interior surface as the tooth is being seated on the adaptor
thereby compressing the biasing element until the second end passes
over the ramped catch and the biasing element urges the second end
towards the aperture when the tooth is substantially seated on the
adaptor.
40. The retainer pin as set forth in claim 38 wherein the body is
substantially rectangular in cross-section.
41. The retainer pin as set forth in claim 38 wherein the body is
substantially square in cross-section and further comprises rounded
out side corners.
42. The retainer pin as set forth in claim 38 wherein the body is
substantially circular in cross-section.
43. The retainer pin as set forth in claim 38 wherein the biasing
element is a spring.
44. The retainer pin as set forth in claim 38 wherein the biasing
element is an elastomer plug.
45. The retainer pin as set forth in claim 38 wherein the biasing
element comprises a first magnet disposed in the passageway and a
second magnet disposed on the first end, the magnets configured to
repel one another when the retainer pin is inserted into the
passageway, the magnets having sufficient magnetic field strength
to urge the second end towards the aperture when the tooth is
substantially seated on the adaptor.
46. A bucket tooth and adaptor assembly for an excavation tool, the
assembly comprising: a) an adaptor comprising: i) a rear portion
adapted for attaching to an excavation tool, ii) a front portion
adapted for a sliding fit with a corresponding socket disposed on a
bucket tooth, iii) 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, iv) a substantially planar first surface disposed on
a portion of the exterior surface, and v) a passageway extending
from the planar surface at least partially into the adaptor, the
passageway adapted to receive a retainer pin for releasably
attaching the bucket tooth to the adaptor; b) a bucket tooth
adapted to releasably attach to the adaptor, comprising: i) a
longitudinal body comprising a front tip portion adapted for
excavating disposed on one end and a rear portion disposed on an
opposing end, ii) a socket disposed on the rear portion, the socket
comprising a mouth, a side wall and an interior mating surface
adapted for sliding fit onto the adaptor, iii) a substantially
planar second surface disposed on a portion of the interior mating
surface adapted to line up with the planar first surface when the
tooth is substantially seated on the adaptor, iv) an aperture
disposed on the planar second surface, the aperture adapted to
substantially align with the passageway when the tooth is
substantially seated on the adaptor, and v) a catch disposed on the
planar second surface between the mouth and the aperture, the catch
adapted to urge a retainer pin disposed in the passageway to seat
into the aperture when the tooth is substantially seated on the
adaptor thereby preventing the tooth from being removed from the
adaptor; and c) a retainer pin, comprising: i) a longitudinal body
having first and second ends, the body adapted to be inserted into
the passageway, ii) a biasing element disposed on the first end,
the biasing element adapted to compress when the retainer pin is
inserted into the passageway and the tooth is being substantially
seated on the adaptor, and iii) the second end adapted to pass over
the catch and to seat in the aperture when the retainer pin is
inserted in the passageway and the tooth is being seated onto the
adaptor whereupon the biasing element urges the second end to seat
into the aperture once the tooth is substantially seated onto the
adaptor.
47. The assembly as set forth in claim 46 wherein the excavation
tool is a tool selected from the group comprising a dipper bucket,
a front-end loader bucket, a mining shovel bucket, an-excavator
bucket, a bucket wheel trencher, a chain trencher and a dredging
cutterhead.
48. The assembly as set forth in claim 46 wherein the rear portion
is U-shaped and adapted to attach to a lip of an excavation
tool.
49. The assembly as set forth in claim 46 wherein the front portion
comprises a key having a substantially flat front end.
50. The assembly as set forth in claim 49 wherein the flat front
end is substantially perpendicular to a longitudinal axis of the
adaptor.
51. The assembly as set forth in claim 49 wherein the key has a
cross-sectional area that is polygon-shaped in profile.
52. The assembly as set forth in claim 51 wherein the polygon is
selected from the group comprising a triangle, a square, a
rectangle, a rhombus, a trapezoid, a pentagon, a hexagon, a
heptagon and an octagon.
53. The assembly as set forth in claim 49 wherein the key has a
cross-sectional area that is elliptical in profile.
54. The assembly as set forth in claim 46 wherein the base is
substantially circular in cross-section.
55. The assembly as set forth in claim 54 wherein the intermediate
portion is cone-shaped as it narrows from the base to the key.
56. The assembly as set forth in claim 55 wherein the intermediate
portion is elliptical in cross-section and the key is rectangular
in cross-section.
57. The assembly as set forth in claim 56 wherein the key further
comprises a substantially flat front end that is substantially
perpendicular to a longitudinal axis of the adaptor.
58. The assembly as set forth in claim 46 wherein the planar
surface is substantially vertical.
59. The assembly as set forth in claim 58 wherein the planar
surface is substantially parallel to a longitudinal axis of the
adaptor.
60. The assembly as set forth in claim 59 wherein the passageway is
substantially perpendicular to the planar surface.
61. The assembly as set forth in claim 60 wherein the passageway is
approximately rectangular in cross-section.
62. The assembly as set forth in claim 61 wherein the passageway is
approximately square in cross-section.
63. The assembly as set forth in claim 62 wherein the passageway
comprises rounded corners.
64. The assembly as set forth in claim 60 wherein the passageway is
approximately circular in cross-section.
65. The assembly as set forth in claim 46 wherein the socket
narrows in cross-sectional area from the mouth to a bottom key-way
that substantially corresponds to the front portion of the
adaptor.
66. The assembly as set forth in claim 65 wherein the bottom
key-way comprises a bottom flat surface that is substantially
perpendicular to the longitudinal body.
67. The assembly as set forth in claim 66 wherein the
cross-sectional area of the bottom key-way is polygon-shaped.
68. The assembly as set forth in claim 67 wherein the polygon is
selected from the group comprising a triangle, a square, a
rectangle, a rhombus, a trapezoid, a pentagon, a hexagon, a
heptagon and an octagon.
69. The assembly as set forth in claim 66 wherein the
cross-sectional area of the bottom key-way is elliptical
shaped.
70. The assembly as set forth in claim 46 wherein the mouth is
substantially circular in cross-section.
71. The assembly as set forth in claim 65 wherein the socket
defines a cone-shaped opening as it narrows from the mouth to the
bottom key-way.
72. The assembly as set forth in claim 71 wherein the cone-shaped
opening is elliptical in cross-section and the bottom key-way is
rectangular in cross-section.
73. The assembly as set forth in claim 72 wherein the bottom
key-way comprises a bottom flat surface that is substantially
perpendicular to the longitudinal body.
74. The assembly as set forth in claim 46 wherein the planar
surface is substantially vertical.
75. The assembly as set forth in claim 74 wherein the planar
surface is substantially parallel to the longitudinal body.
76. The assembly as set forth in claim 46 wherein the catch is a
ramp that compresses the biasing element of the retainer pin when
the retainer pin slides along the ramp as the tooth is seated onto
the adaptor until the retainer pin is urged into the aperture by
the biasing element thereby securing the tooth to the adaptor.
77. The assembly as set forth in claim 76 wherein the aperture is a
frusto-conical opening.
78. The assembly as set forth in claim 77 wherein the aperture
extends through the side wall to an exterior side of the
longitudinal body to provide communication to the retainer pin
whereby a tool can be inserted into the aperture and engage the
retainer pin to compress the biasing element and allow the retainer
pin to clear the catch thereby enabling the tooth to be removed
from the adaptor.
79. The assembly as set forth in claim 46 wherein the second end of
the retainer pin body is further adapted to slide along a ramped
catch disposed on the interior surface as the tooth is being seated
on the adaptor thereby compressing the biasing element until the
second end passes over the ramped catch and the biasing element
urges the second end towards the aperture when the tooth is
substantially seated on the adaptor.
80. The assembly as set forth in claim 79 wherein the body is
substantially rectangular in cross-section.
81. The assembly as set forth in claim 80 wherein the body is
substantially square in cross-section and further comprises rounded
out side corners.
82. The assembly as set forth in claim 79 wherein the body is
substantially circular in cross-section.
83. The assembly as set forth in claim 46 wherein the biasing
element is a spring.
84. The assembly as set forth in claim 46 wherein the biasing
element is an elastomer plug.
85. The assembly as set forth in claim 46 wherein the biasing
element comprises a first magnet disposed in the passageway and a
second magnet disposed on the first end, the magnets configured to
repel one another when the retainer pin is inserted into the
passageway, the magnets having sufficient magnetic field strength
to urge the second end towards the aperture when the tooth is
substantially seated on the adaptor.
86. The assembly as set forth in claim 46 wherein the base of the
adaptor further comprises at least one stabilizing lug and the
socket of the tooth further comprises at least one positioning slot
whereby the at least one stabilizing lug is adapted to mate with
the at least one positioning slot when the tooth is substantially
seated on the adaptor.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to excavating equipment, more
particularly, to bucket tooth and adaptor assemblies for use on
dipper buckets.
[0003] 2. Description of the Related Art
[0004] 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.
[0005] A chisel-like tooth of the assembly reduces the initial
contact mass of the bucket edge moving into the material being
excavated by focussing 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, multidirectional 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.
[0006] Canadian Patent 1,243,059 and U.S. Pat. No. 4,481,728 are
exemplary of the first generation elliptical tooth and adaptor
system. This system demonstrated 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 for use in the field.
Some of this assembly's limitations include the use of an oversized
locking pin that incorporates compressive elastomeric material
vulcanized between two rigid members of the locking pin.
[0007] Excessive force has to be applied by a sledgehammer to
sufficiently compress the pin to permit full insertion into a
smaller hole that receives 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.
[0008] Another problem with this type of tooth and adaptor system
is the physical properties of the vulcanized elastomeric material
used in a lock pin to 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.
[0009] 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.
[0010] Other limitations 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.
[0011] Other systems include large gaps on the assembled tooth and
adaptor, and within and around the lock pinholes. This leaves 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 can deteriorate these important dimensional
load-bearing surfaces.
[0012] 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. In addition, the elastomeric material
incorporated in the retainer pin is exposed to the chemical effects
of the ore (i.e., tar sand) and this contributes to the premature
breakdown of this material diminishing its ability to lock the
tooth to the adaptor. 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.
[0013] It is, therefore, desirable to provide a tooth and adaptor
assembly for a dipper bucket that overcomes the limitations of the
conventional equipment described above.
BRIEF SUMMARY OF THE INVENTION
[0014] According to the preferred embodiment of this invention, a
tooth and adaptor assembly for a dipper bucket includes an adaptor
having a front portion, an intermediate portion and a rear portion.
The rear portion is adapted for attaching to a conventional dipper
bucket. 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. According to one
arrangement, the intermediate portion has an elliptical
cross-section and the front portion has a substantially flat front
end. According to another arrangement, a portion of the exterior
surface of the intermediate portion is substantially planar thereby
making the intermediate portion approximately D-shaped in cross
section. A cavity is disposed on the planar surface, this cavity
being transverse to a longitudinal axis passing through the
intermediate portion. The cavity can be circular, rectangular or
square in cross-section.
[0015] The preferred assembly also includes a tooth having a front
tip portion adapted for excavating and a rear portion extending
from the front end. The rear portion of the tooth includes 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 of
the adaptor. 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 planar portion of the exterior surface
of the intermediate portion of the adaptor.
[0016] The rear portion of the tooth also has a smaller opening,
which secures a retainer pin. The aperture is in alignment with the
adaptor passageway when the tooth is fully seated on the adaptor.
In the preferred embodiment, the aperture extends through the tooth
thereby providing communication from the outer tooth surface to the
passageway. The retainer pin is disposed in the adaptor passageway
to extend toward and engage the aperture in the tooth thereby
securing the tooth on the adaptor. The retainer pin can be
extracted from the smaller opening in the tooth by external
means.
[0017] In an alternative embodiment, the assembly utilizes a
compressible retainer pin to engage and disengage the tooth from
the adaptor. There is no bottom through-hole in the bottom of the
tooth to "drift" the retainer pin out in order to disassemble the
tooth from the adaptor. This prevents the entry of highly
pressurized compaction forces from beneath that can force the
typical base exposed retainer pin upward and out of their latched
position.
[0018] In yet another embodiment, the assembly includes a tooth, an
adaptor, a retainer pin and a biasing element. The tooth and
adaptor are configured such that the mated surfaces of the
assembled components minimize debris from entering the interstitial
space between the tooth and the adaptor when they are in a coupled
and latched position. Preferably, the retainer pin is a solid pin,
tapered at one end, having a square cross-section with rounded
corners. The biasing element can consist of an elastomeric plug
and/or a spring element that maintains outward pressure on the
retainer pin to promote locking engagement within the small hole of
the tooth. A ramp disposed in the socket between the mouth of the
socket and the small hole of the tooth compresses the biasing
element of the retainer pin as the tooth is seated onto the
adaptor. As the small hole of the tooth begins to align with the
adaptor cavity, the retainer pin passes over the crest of the ramp
and is urged forward by the biasing element to engage the small
hole thereby securing the tooth on the adaptor.
[0019] According to another arrangement, 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 a cavity 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. These
additional mated-load bearing surfaces help to keep the tooth
stable on the adaptor while a maintenance worker is changing out
the tooth. One or more stabilizing lugs protrude outward from the
adaptor thrust bearing surface that mate with positioning slot(s)
positioned on the thrust bearing surface of the tooth.
[0020] The complementary shapes of the front and intermediate
portions of the adaptor and the tooth socket more effectively
distribute the shock and bearing loads 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.
[0021] The retainer pin can be easily manipulated externally with a
simple tool, such as a drift punch, entered into the small hole of
the tooth to permit installation and removal of the tooth. The
configuration of the retainer pin prevents chemically active ore
from entering the adaptor cavity and having an adverse effect on an
elastomeric biasing element. Accordingly, the elastomeric material
and/or spring mechanism and retainer pin can be used over the
course of several tooth change outs, if necessary.
[0022] According to one aspect of the invention, an adaptor for
releasably attaching a bucket tooth to an excavation tool includes
a rear portion adapted for attaching to an excavation tool; a front
portion adapted for a sliding fit with a corresponding socket
disposed on a bucket 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 front portion; a substantially planar surface disposed on a
portion of the exterior surface; and a passageway extending from
the planar surface at least partially into the adaptor, the
passageway being adapted to receive a retainer pin for releasably
attaching the bucket tooth to the adaptor.
[0023] According to another aspect of the invention, a bucket tooth
for releasably attaching an adaptor to an excavation tool includes
a longitudinal body that has a front tip portion adapted for
excavating disposed on one end and a rear portion disposed on an
opposing end; a socket disposed on the rear portion, the socket
having a mouth, a side wall and an interior mating surface adapted
for a sliding fit onto an exterior surface of an adaptor; a
substantially planar surface disposed on a portion of the interior
mating surface; an aperture disposed on the planar surface, the
aperture being adapted to substantially align with a passageway
disposed on the adaptor; and a catch disposed on the planar surface
between the mouth and the aperture, the catch being adapted to
secure a retainer pin disposed in the passageway to the aperture,
the retainer pin including a biasing element adapted to urge the
retainer pin to engage the aperture when the tooth is substantially
seated on the adaptor thereby preventing the tooth from being
removed from the adaptor.
[0024] According to yet another aspect of the invention, a retainer
pin is adapted for releasably attaching a bucket tooth to an
adaptor, the tooth including a socket having an interior surface
and adapted for sliding fit on to the adaptor, a longitudinal body
having first and second ends, the body being adapted to be inserted
into a passageway disposed on an adaptor; a biasing element
disposed on the first end; and the second end adapted to seat in an
aperture disposed on a socket interior surface of a bucket tooth
when the retainer pin is inserted first end first into the
passageway of the adaptor thereby retaining the tooth on the
adaptor once the tooth is substantially seated on the adaptor.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0025] FIG. 1 is a perspective view depicting a tooth uncoupled
from an adaptor that is mounted to a dipper bucket.
[0026] FIG. 2 is a perspective view depicting a tooth being seated
on an adaptor.
[0027] FIG. 3 is a side elevational view depicting the tooth and
adaptor assembly of FIG. 1 with the tooth seated on the
adaptor.
[0028] FIG. 4 is a top plan view depicting the tooth and adaptor
assembly of FIG. 1 with the tooth seated on the adaptor.
[0029] FIG. 5 is a side elevational view depicting the tooth and
adaptor assembly of FIG. 1 with the tooth uncoupled from the
adaptor.
[0030] FIG. 6 is a top plan view depicting the tooth and adaptor
assembly of FIG. 1 with the tooth uncoupled from the adaptor.
[0031] FIG. 7 is a left side elevational cross-section view
depicting a tooth of FIG. 4 as shown along section lines
VII-VII.
[0032] FIG. 7A is a left side elevational cross-section view
depicting the tooth of FIG. 7 with a slot for a stabilizing
lug.
[0033] FIG. 8 is a right side elevational cross-section view
depicting the tooth of FIG. 4 shown along section lines
VIII-VIII.
[0034] FIG. 9 is a top plan cross-sectional view depicting the
tooth of FIG. 3 as shown along section lines IX-IX.
[0035] FIG. 10 is a left side elevational view depicting the
adaptor of FIG. 1.
[0036] FIG. 10A is a left side elevation view depicting the adaptor
of FIG. 10 with a stabilizing lug.
[0037] FIG. 11 is a top plan view depicting the adaptor of FIG.
1.
[0038] FIG. 11A is a top plan view depicting the adaptor of FIG. 11
with a stabilizing lug.
[0039] FIG. 12 is a side elevational view depicting a retainer pin
for use with the tooth and adaptor assembly of FIG. 1.
[0040] FIG. 13 is a top cross sectional plan view depicting the
tooth and adaptor assembly of FIG. 3 as shown along section lines
XIII-XIII.
[0041] FIG. 13A is a top cross sectional plan view displaying an
alternate embodiment of the retainer pin.
[0042] FIG. 14 is an end elevational cross-section view depicting
the tooth and adaptor assembly of FIG. 4 as shown along section
lines XIV-XIV.
[0043] FIG. 15 is a perspective view depicting a backhoe with a
dipper bucket.
[0044] FIG. 16 is an elevational side view depicting an excavator
with a dipper bucket.
[0045] FIG. 17 is an elevational side view depicting a front-end
loader with a mining bucket.
[0046] FIG. 18 is a perspective view depicting a bucket-wheel
trencher excavator with a plurality of toothed buckets.
[0047] FIG. 19 is a perspective view depicting a trencher with a
chain equipped with a plurality of tooth and adaptor
assemblies.
[0048] FIG. 20 is an elevational side view depicting a cutting head
for a dredging excavator.
DETAILED DESCRIPTION OF THE INVENTION
[0049] Referring to FIGS. 1 and 2, a representative embodiment of
the present invention is shown. The tooth/adaptor assembly 10
broadly consists of excavation tooth 12, adaptor 14, retainer pin
16, and biasing element 17. Adaptor 14 comprises elongated U-shaped
member 15 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 forced outwardly
from the adaptor cavity 20 by the biasing element 17 to fit snugly
into aperture 21 on tooth 12. 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 inserting a
tool, such as a drift punch or similarly shaped device, into
aperture 21 to engage pin 16 and compress biasing element 17. This
causes pin 16 to disengage from aperture 21 on tooth 12 thereby
allowing tooth 12 to be removed from adaptor 14.
[0050] 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 tip 22 designed for excavating. As more clearly shown in
FIG. 13, tooth 12 is secured to adaptor 14 with retainer pin 16
seated in cavity and engaging aperture 21. 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 23
that is generally circular in cross-section, intermediate
elliptical tapered cone portion 24 and front block portion 35.
[0051] One side of the base 23 and intermediate portions 23 and 24
have a flat surface 25 that gives the base portion 23 and
intermediate portion 24 a generally D-shaped or 3/4 round
cross-section. The flat surface 25 has a planar axis that can be
positioned substantially vertical on adaptor 14, although other
configurations can be used. Retainer pin cavity 20 on flat surface
25 can be transverse to longitudinal axis 11 of assembly 10. To
couple tooth 12 and adaptor 14 together, tooth 12 comprises socket
26 that receives front, intermediate and base portions 35, 24 and
23 of adaptor 14. When tooth 12 is seated on adaptor 14, thrust
bearing surface 27 of tooth 12 contacts thrust bearing surface 31
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.
[0052] Moreover, when tooth 12 is seated on adaptor 14, aperture 21
aligns with cavity 20 to provide a substantially continuous
passageway 28 for receiving retainer pin 16. Front portion 35 is a
key adapted to prevent tooth 12 from rotating on adaptor 14 when
fully seated on adaptor 14. In the embodiment described herein,
front portion 35 has a rectangular cross-section. The cross-section
of front portion 35 can be of any suitable cross-sectional shape
that will prevent tooth 12 from rotating on adaptor 14 when fully
seated on adaptor 14. Examples of suitable polygon shapes for front
portion 35 include triangle, square, rhombus, trapezoid, pentagon,
hexagon, heptagon and octagon. Front portion 35 can also be
elliptical in cross-section in addition to any other curved
cross-section that will prevent tooth 12 from rotating on adaptor
14.
[0053] 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 is intersected by a socket-opening 26 that has a
substantially circular interior load bearing surface 29 to match
base 23 of adaptor 14. Relief cavity 33 is a relief groove that
separates load surface 29 from elliptical cone surface 30. Relief
cavity 33 is relatively circular in shape and offers additional
relief clearance for adaptor transition zone edges 32 on tooth 12
when tooth 12 is fully seated on adaptor 14.
[0054] Sidewalls 34a to 34d and primary thrust bearing surface 39
of key-way 52 provide an opening to receive front block 35 of
adaptor 14 in a sliding fit. In one embodiment, front block 35 of
adaptor 14 and key-way 52 are rectangular in cross section. The
cross-section of key-way 52 can be of any suitable cross-sectional
shape that will prevent tooth 12 from rotating on adaptor 14 when
fully seated on adaptor 14. Examples of suitable polygon shapes for
key-way 52 include triangle, square, rhombus, trapezoid, pentagon,
hexagon, heptagon and octagon. Key-way 52 can also be elliptical in
cross-section in addition to any other curved cross-section that
will prevent tooth 12 from rotating on adaptor 14 so long as
key-way 52 and front portion 35 are complementary in shape and
fit.
[0055] Cone surface 30 and circular base 29 further comprises flat
surface 38 that give this intermediate portion of socket 26 a
generally D-shaped or 3/4 round cross-section. Ramp 60 leads from
thrust bearing surface 27 in socket 26 towards ramp crest 62 that
is adjacent to aperture 21. In one embodiment, aperture 21 is
tapered, or frusto-conical, in shape and configuration.
[0056] Referring to FIGS. 10 and 11, side and top views of adaptor
14 are shown, respectively. Adaptor 14 comprises of adaptor base
23, which is generally circular, elliptical body 24 and front block
35. Front block 35 is, preferably, rectangular and comprises of
sidewalls 36a to 36d and primary thrust surface 37. Elliptical body
24 tapers from transition 32 to front block 35. Flat surface 25 is
disposed on elliptical body 24 and adaptor base 23. Retainer pin
cavity 20 is disposed on flat surface 25 and is generally
transverse to the horizontal axis of adaptor 14. Retainer pin
cavity 20 aligns with aperture 21 of tooth 12 when tooth 12 is
fully seated onto adaptor 14. Front block 35 is adapted for a
sliding fit with the bottom of tooth socket 26 which is defined by
sidewalls 36a to 36d and thrust bearing surface 37. In one
embodiment, adaptor front block 35 can have a generally rectangular
cross section, with flat front mating surface 37 having a width
that is greater than its height, that is, top and bottom mating
surfaces 36a and 36c are wider than flat side mating surfaces 36b
and 36d.
[0057] Referring to FIGS. 7A, 10A and 11A, another embodiment of
tooth 12 and adaptor 14 are shown. As illustrated in FIGS. 10A and
11A, adaptor 14 further comprises at least one stabilizing lug 66
extending away from base portion 23 and bearing thrust surface 31.
In this embodiment, stabilizing lug 66 fits into positioning slot
67 located on tooth 12, as shown in FIG. 7A, to further stabilize
tooth 12 when tooth 12 is substantially seated on adaptor 14.
[0058] A side view of retainer pin 16 is shown in FIG. 12. Retainer
pin 16 comprises main body 40, O-ring groove 41, tapered tip 42 and
biasing element 17. Referring to FIGS. 13 and 13A, pin tip 42 is
tapered in one embodiment to ensure firm engagement into aperture
21 to prevent debris from entering cavity 20. This uniform
metal-to-metal surface contact is maintained by the outward
compression, as described below, that encloses passageway 28 and
the interior of assembly 10. Positioned firstly within the adaptor
retainer pin hole 20 is biasing element 17 which urges the retainer
pin 16 outward to insert retainer pin tip 42 into aperture 21,
thereby securing the tooth 12 firmly on the adaptor 14. In one
embodiment, biasing element 17 can be made of corrosion resistant
spring material.
[0059] In FIG. 13, front cross-sectional views of assembly 10 are
shown with spring mechanism 17 and retainer pin 16 housed in the
adaptor retainer pin cavity 20. The coupling of tooth 12 onto
adaptor 14 forces tapered tip 42 of retainer pin 16 to travel up
ramp 60 thereby compressing biasing element 17. As tapered tip 42
passes over ramp crest 62, biasing element 17 urges tapered tip 42
into aperture 21 when tooth 12 is fully coupled to adaptor 14.
[0060] In another embodiment, biasing element can be a resilient
elastomeric plug made of rubber, polyurethane or any other suitable
elastomer material as known to those skilled in the art that can
provide the force required to urge retainer pin 16 toward and
engage aperture 21 on tooth 12 when tooth 12 is seated on adaptor
14. In another embodiment, as shown in FIG. 13A, biasing element 17
can be a pair of magnets 48 and 50 placed in cavity 20 such that
magnets 48 and 50 repel one another. In this manner, the magnetic
force that causes magnets 48 and 50 to repel one another urges
retainer pin 16 toward aperture 21 and engage it thereby retaining
tooth 12 on adaptor 14. To retract retainer pin 16 from aperture
21, a simple tool is inserted into aperture 21 and inward force is
applied to move retainer pin 16 back onto biasing element 17
thereby disengaging retainer pin 16 from aperture 21 so that tooth
12 can be removed from adaptor 14. Retainer pin 16 is of a rigid
construction and may be manufactured from steel or alloys having
suitable strength, wear and corrosion resistant properties.
[0061] Referring to FIG. 14, a cross-sectional rear view of tooth
12 seated on adaptor 14 is shown. Flat surface 38 of tooth 12
aligns and mates with flat surface 25 of adaptor 14. Cavity 20
aligns with aperture 21 to form passageway 28. Adaptor 14 is sized
to provide a close fit with socket 26 of tooth 12. With tooth 12
and adaptor 14 configured in this manner, tooth 12 is prevented
from rotating on adaptor 14.
[0062] The embodiments shown herein are related to tooth and
adaptor assemblies for use with dipper buckets. However, it should
be obvious to those skilled in the art that the tooth and adaptor
assemblies described herein can be used on a variety of heavy
equipment and excavating tools. As an example, tooth and adaptor
assemblies can be used on backhoes 70 (FIG. 15) and excavators 72
(FIG. 16) in addition to mining shovel buckets or front-end loader
buckets 74 (FIG. 17).
[0063] Other types of excavating tools include bucket wheel and
chain trenchers. Bucket wheel trenchers are large diameter wheels
having a plurality of buckets spaced about the circumference of the
wheel. Each bucket, in turn, has a number of teeth and adaptor
assembles. Bucket wheels are typically used in open-pit mining
operations and to excavate pipeline trenches. An example of such a
bucket wheel 76 is shown in FIG. 18. Chain trenchers are a
different type of excavating tool as they comprise an endless chain
having a plurality of tooth and adaptor assemblies attached around
the chain not unlike a chainsaw. Trenchers are used to cut trenches
in the ground. An example of such a trencher 78 is shown in FIG.
19. Yet another example of excavating tools that use tooth and
adaptor assemblies are cutterheads as used on dredging equipment.
These cutterheads are rotary cutting devices and have the teeth and
adaptor assemblies disposed about the semispherical surface of the
cutterhead such that they are pointed in the direction of
cutterhead rotation. An example of a cutterhead 80 is shown in FIG.
20.
[0064] 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 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 scope of the invention is defined and limited
only by the claims that follow.
* * * * *