Note: Descriptions are shown in the official language in which they were submitted.
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RETAINING PIN ASSEMBLY
TECHNICAL FIELD
S A retaining pin assembly for detachably connecting a first member and a
second
member such as an adapter and a disposable wear part on a piece of
earthworking equipment.
BACKGROUND OF THE INVENTION
Earthworking equipment often utilizes disposable wear parts which are
connected to the earthworking equipment by way of an adapter and a retaining
mechanism.
Examples of such disposable wear parts include ripper shank (adapter)
protectors (including
ripper tips and shank shims), teeth and/or tips for bucket shovels, teeth
and/or tips for
excavation buckets, and any other disposable wear part which is attached to
the earthworking
equipment by means of a retaining mechanism.
Often the retaining mechanism is comprised of a retaining pin assembly such as
that described in U.S. Patent No. 4,823,486 (Diekevers et al) and U.S. Patent
No. 5,009,017
(Diekevers et al).
The retaining pin assembly described in Diekevers et al is comprised of a
grooved retaining pin and a keeper means. The keeper means is comprised of a
grooved
metallic washer and a resilient retaining ring. The keeper means is designed
to be placed within
a recess in the adapter and then detachably fixed to the retaining pin to
restrain axial movement
of the retaining pin relative to the metallic washer.
The retaining pin assembly in Diekevers et al must be assembled and
disassembled using tools including sledgehammers and punches which provide a
driving force.
During assembly, sufficient driving force must be provided to expand the
resilient retaining ring
within the groove in the metallic washer and to advance the retaining pin
until the resilient
retaining ring "springs inward" into place in the groove in the retaining pin.
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During disassembly, sufficient driving force must theoretically be provided to
shear the resilient retaining ring so that the retaining pin can be moved
axially relative to the
metallic washer. In practice, the forces required to cause pure shearing of
the retaining ring are
extreme, and typically the retaining ring is destroyed and/or the metallic
washer is fractured
during disassembly of the retaining pin assembly.
The disassembly of the retaining pin assembly in Diekevers et al is relatively
time consuming, labour intensive and dangerous. Two persons are typically
required, with one
person holding a punch so that it is aligned with the axis of the retaining
pin and the second
person striking the punch with a sledgehammer. There is a risk of injury to
the persons
involved due to being struck either by the sledgehammer or by debris which is
scattered during
the disassembly process.
In addition, the striking of the retaining pin, particularly during
disassembly of
the retaining pin mechanism, often damages the retaining pin so that it cannot
be reused.
Furthermore, all or a portion of the retaining ring may remain in the groove
on the retaining pin
after the retaining pin assembly is disassembled and may be difficult to
remove from the
groove, thus effectively rendering the retaining pin unusable. Even if the
retaining pin is not
damaged or rendered unusable, the resilient retaining ring must be replaced
after each use and
often the metallic washer must also be replaced.
There therefore remains a need for a retaining mechanism which can be
disassembled easily and safely and typically without the need for significant
driving forces and
for a retaining mechanism which includes components which can often be reused.
SUMMARY OF THE INVENTION
The present invention is a retaining mechanism for detachably connecting a
first
member and a second member. More particularly, the retaining mechanism is
comprised of a
retaining pin assembly.
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The retaining pin assembly is relatively easy to assemble and disassemble and
includes parts which may typically be reused. In normal use, the disassembly
of the retaining
pin assembly does not require shearing or other destruction of any of its
components. In a
preferred embodiment, the retaining pin assembly does, however, provide for a
backup
mechanism for disassembly of the retaining pin assembly, which backup
mechanism includes a
shear plane for shearing of one of the parts of the retaining pin assembly.
The first member and the second member may be comprised of any parts,
members or elements which must be detachably connected with each other. In
preferred
embodiments of the invention, the first and second members are comprised of
components of
earthworking equipment. More specifically, in preferred embodiments the first
member is
comprised of an adapter and the second member is comprised of a wear part such
as a tooth or a
tip for a piece of earthworking equipment.
As used herein, the word "diameter" is intended to refer to a transverse
dimension regardless of whether the dimension is circular or some other shape.
As a result, the
word "diameter" as used herein is intended to convey an indication of relative
size without
regard to the shape of the dimension in question.
In a first aspect, the invention is a retaining pin assembly for detachably
connecting a first member and a second member, the first member defining a
transverse bore
extending therethrough, the second member comprising a pair of sidewalls for
straddling the
first member to provide a member interface between the first member and each
of the sidewalls,
each of the sidewalls defining an aperture, wherein the apertures are
substantially axially
aligned with the transverse bore when the first member and the second member
are in a
connecting configuration, wherein one of the first member and the second
member defines a
recess, wherein the recess is adjacent to one of the member interfaces and is
in substantial axial
alignment with the transverse bore and the apertures when the first member and
the second
member are in the connecting configuration, the retaining pin assembly
comprising:
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(a) a retaining pin for insertion in the transverse bore such that a bore
interface is
provided between the retaining pin and the transverse bore;
(b) a retaining washer for positioning in the recess; and
(c) a fastener for fastening the retaining washer to the retaining pin.
The fastener may be comprised of any device, structure or mechanism which can
fasten the retaining washer to the retaining pin either removably or
permanently. For example,
the fastener may be comprised of one or more bolts, nuts, studs, rivets,
screws, welds or
adhesives. Preferably the fastener is comprised of a removable fastening
mechanism such as a
bolt, nut or screw.
Preferably the retaining pin is comprised of pin threads and the fastener is
comprised of complementary fastener threads so that the retaining washer is
fastened to the
retaining pin with a threaded connection. Alternatively, instead of a threaded
connection the
retaining pin and the fastener may be connected together by friction or by a
suitable latch
mechanism.
In one embodiment, the retaining pin defines a socket section with internal
threads and the fastener is comprised of a bolt with external threads. In a
second embodiment,
the retaining pin is comprised of a plug section with external threads and the
fastener is
comprised of a socket section with internal threads, in which case the
fastener is comprised of a
nut or other suitable device, structure or mechanism.
The retaining pin may be solid or hollow. Where the retaining pin defines the
socket section the retaining pin is preferably hollow, defining a longitudinal
bore extending
from a first end of the retaining pin to a second end of the retaining pin so
that debris in the
socket section of the retaining pin can be passed through the longitudinal
bore without
accumulating in the socket section. The longitudinal bore may be comprised of
the socket
section.
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The retaining pin assembly may be configured to be assembled into an
assembled configuration in which the retaining washer is fastened between the
retaining pin and
the fastener. In the assembled configuration, the retaining pin assembly has
an assembled
length. The assembled length is selected to be greater than a distance between
the member
interfaces when the first member and the second member are in the connecting
configuration.
The recess may be defined by either the first member or the second member.
The recess may also be defined partially by the first member and partially by
the second
member. In a preferred embodiment the recess is defined by the first member.
The retaining washer is designed to be placed in the recess to restrict the
axial
movement of the retaining pin when the retaining pin assembly is in the
assembled
configuration. As a result, the retaining washer is designed to have a
diameter which is greater
than the diameter of both the transverse bore and the aperture which is
adjacent to the recess
when the first member and the second member are in the connecting
configuration. The
retaining washer may be constructed of steel or of any other suitable
material.
The retaining pin assembly may be comprised of an integrated retainer
component which comprises the retaining washer and the fastener. The
integrated retainer
component may be comprised of a plurality of parts or components which are
fastened together
either temporarily or permanently. Preferably, however, the integrated
retainer component is
either comprised of a plurality of parts or components which are permanently
fastened together
by welding or other suitable means, or is constructed of a single piece of a
suitable material.
Where constructed of a single piece of material, the integrated retainer
component may be fabricated in any suitable manner, such as by machining from
a billet of
material, casting or forging. In some preferred embodiments, the integrated
retainer component
is forged.
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The use of the integrated retainer component may assist in simplifying the
manufacture and use of the retaining pin assembly by reducing the number of
parts which are
included in the retaining pin assembly. In addition, the use of the integrated
retainer component
may provide greater flexibility in configuring the retaining pin assembly.
However, the use of the integrated retainer component will for some
applications
of the invention require modification of the first member and/or the second
member to facilitate
assembly of the retaining pin assembly, since the fastener will typically be
designed to extend
across the member interface when the retaining washer is positioned in the
recess, thus
effectively preventing the retaining washer from being positioned in the
recess before the first
member and the second member are placed in the connecting configuration.
In one embodiment, the modification involves providing the second member
with a slot or a groove to accommodate the fastener and a groove to
accommodate the retaining
washer so that the retaining washer can be positioned in the recess after the
first member and
the second member are placed in the connecting configuration. In other
embodiments, the
modification may involve providing the second member with a slot or a groove
to
accommodate the fastener and providing the first member with a groove to
accommodate the
retaining washer. In yet other embodiments, the modification may involve
providing the
second member with a slot or groove to accommodate the fastener and providing
both the
second member and the first member with a groove to accommodate the retaining
washer.
The retaining washer may define a shear plane for shearing of the retaining
washer. The shear plane may be comprised of a portion of the retaining washer
which is
relatively more susceptible to shear failure than the remainder of the
retaining washer. This
susceptibility may be provided by constructing all or a portion of the
retaining washer of a
material having a relatively low shear strength, or may be provided by
constructing all or a
portion of the retaining washer so that it has a "shearable thickness" having
regard to the forces
which will be applied to the retaining washer.
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The purpose of the shear plane is to provide a mechanism for disassembly of
the
retaining pin assembly if either the fastener is designed to permanently
fasten the retaining
washer to the retaining pin or if for some reason the fastener cannot be
removed from the
retaining pin assembly during disassembly of the retaining pin assembly.
The shear plane is designed to be generally coincident with a plane which will
facilitate removal of the retaining pin from the transverse bore. For example,
the shear plane
may be generally coincident with either the diameter of the aperture which is
positioned
adjacent to the recess or with the diameter of the transverse bore. Preferably
the shear plane is
generally coincident with the smaller of these two diameters so that the
retaining pin can be
removed from the transverse bore from either side of the first member. If the
shear plane is
generally coincident with the diameter of the transverse bore, it is more
particularly preferably
generally coincident with the bore interface in order to provide for a clear
line of shear between
an axial driving force acting on either the retaining pin or the fastener and
a reaction force
1 S acting on the retaining washer.
Preferably the shear plane is provided by a region of shearable thickness or
an
overall shearable thickness of the retaining washer. In some embodiments the
shearable
thickness is provided as a groove in the retaining washer. Alternatively the
shearable thickness
may be provided as a region of shearable thickness in the retaining washer or
an overall
shearable thickness of the retaining washer.
Where the shearable thickness is provided by a groove, the groove preferably
generally coincides with the bore interface and the transverse bore.
Alternatively, the groove
could generally coincide with the diameter of the aperture which is positioned
adjacent to the
recess. Preferably the groove is an annular groove. The groove provides a
region of reduced
thickness in the retaining washer which is relatively more easy to shear than
the remainder of
the retaining washer.
The groove may be comprised of a profile which is either symmetrical or
asymmetrical. The profile may be comprised of any shape and depth. Exemplary
shapes
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include a cone, a parabola, a circle, a rectangle, a triangle and an ellipse,
which shapes may be
complete or truncated. In some preferred embodiments the shape of the profile
is comprised of
a truncated cone.
The retaining pin assembly is preferably designed so that the assembled
configuration and the assembled length of the retaining pin assembly are
defined during the
assembly of the retaining pin assembly. Any device, structure or mechanism
which is effective
to accomplish this objective may be utilized.
For example, the retaining pin may be comprised of a pin shoulder and the
fastener may be comprised of a complementary fastener shoulder, which
shoulders are
configured to engage each other to define the assembled configuration of the
retaining pin
assembly. In other words, the shoulders engage each other to limit the
movement of the
fastener relative to the retaining pin.
In one preferred embodiment, the bolt is comprised of a plug section, a head
section and a washer mounting section located between the plug section and the
head section.
In this preferred embodiment the fastener threads are located on the plug
section.
In this preferred embodiment, the retaining washer defines a washer bore and
the retaining pin
has an outer diameter. Preferably the diameter of the washer bore is less than
the outer
diameter of the retaining pin. Furthermore, in this preferred embodiment the
head section of
the bolt and the washer mounting section of the bolt each have a diameter.
Preferably the
diameter of the washer mounting section is less than the diameter of the
washer bore and
preferably the diameter of the washer bore is less than the diameter of the
head section. In this
preferred embodiment, the retaining pin and the bolt may be comprised of
complementary
shoulders such as a pin shoulder and a bolt shoulder which are configured to
engage each other
to define the assembled configuration of the retaining pin assembly.
Preferably the retaining pin is further comprised of a tool engagement surface
for
facilitating assembly and/or disassembly of the retaining pin assembly. In
some embodiments
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each of the retaining pin and the fastener are preferably comprised of a tool
engagement surface
for facilitating assembly and/or disassembly of the retaining pin assembly.
The tool
engagement surfaces may be comprised of any suitable surface or surfaces and
may be
comprised of external surfaces, internal surfaces or combinations thereof.
Where the fastener and the retaining pin are connected with a threaded
connection, the tool engagement surfaces may be comprised of suitable
engagement surfaces
for engaging a tool which is compatible with a threaded connection, such as a
wrench or a
screwdriver. For example, the tool engagement surfaces may be comprised of
external surfaces
such as hexagonal surfaces or square surfaces for engaging a tool such as a
socket, wrench or
pliers, or the tool engagement surfaces may be comprised of internal surfaces
for engaging a
tool such as an Allen wrench or a screwdriver.
Where the fastener and the retaining pin are connected with a threaded
connection and where the retaining pin assembly is comprised of the integrated
retainer
component, the tool engagement surface on the fastener may be substituted by
providing the
retaining washer with a recess engaging surface which is adapted to engage the
recess in order
to inhibit rotation of the integrated retainer component relative to the
recess. The recess
engaging surface may be comprised of any suitable surface, including a
hexagonal surface, a
square surface or some other "non-circular" shape which defines the periphery
of the retaining
washer.
Where the fastener and the retaining pin are connected with a different type
of
connection, the tool engagement surfaces may be comprised of any suitable
surface such as
necks or hooks for applying an appropriate force to the fastener and the
retaining pin.
Where tool engagement surfaces are provided on each of the retaining pin and
the fastener, the tool engagement surfaces are preferably located adjacent to
opposite ends of
the retaining pin assembly when it is in the assembled configuration, so that
one of the tool
engagement surfaces can be accessed from each end of the retaining pin
assembly.
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For example, where the retaining pin defines a socket section, the socket
section
of the retaining pin may be located adjacent to the first end of the retaining
pin, the tool
engagement surface on the retaining pin may be located adjacent to the second
end of the
retaining pin, and the tool engagement surface on the fastener may be located
on the head
section of the bolt.
Where a tool engagement surface is provided only on the retaining pin, the
tool
engagement surface is preferably located adjacent to one end of the retaining
pin assembly
when it is in the assembled configuration so that it can be accessed from an
end of the retaining
pin assembly.
BRIEF DESCRIPTION OF DRAWINGS
Embodiments of the invention will now be described with reference to the
accompanying drawings, in which:
Figure 1 is a side view of a replaceable tooth connected with an adapter on a
piece of earthworking equipment using a retaining pin assembly according to a
preferred
embodiment of the invention.
Figure 2 is a transverse partial section view of the retaining pin assembly of
Figure 1 taken along Section A - A from Figure 1.
Figure 3 is a partial section view and an end view of a retaining pin
according to
a preferred embodiment of the invention, including a longitudinal bore and a
square external
tool engagement surface.
Figure 4 is a partial section view and an end view of a retaining pin
according to
a preferred embodiment of the invention, including a longitudinal bore and a
hexagonal
external tool engagement surface.
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Figure 5 is a side view of a fastener according to a preferred embodiment of
the
invention, including a hexagonal external tool engagement surface.
Figure 6 is a side view of a fastener according to a preferred embodiment of
the
invention, including a square external tool engagement surface.
Figure 7 is a transverse section view of a retaining washer according to a
preferred embodiment of the invention, including a shear plane comprising a
groove with a
profile in the shape of a symmetrical truncated cone.
Figure 8 is a transverse section view of a retaining washer according to a
preferred embodiment of the invention, including a shear plane comprising a
groove with a
profile in the shape of an asymmetrical truncated cone.
Figure 9 is a transverse section view of a retaining washer according to a
preferred embodiment of the invention, including a shear plane comprising a
groove with a
profile in the shape of a symmetrical truncated parabola.
Figure 10 is a transverse section view of a retaining washer according to a
preferred embodiment of the invention, including a shear plane comprising a
groove with a
profile in the shape of an asymmetrical truncated parabola.
Figure 11 is a transverse section view of a retaining washer according to a
preferred embodiment of the invention, including a shear plane comprising a
groove with a
profile in the shape of a rectangle.
Figure 12 is a schematic representation of shear forces experienced by a
retaining washer according to a preferred embodiment of the invention as a
result of an axial
driving force being applied to either the retaining pin or to the fastener.
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Figure 13 is a side view and an end view of a solid retaining pin according to
a
preferred embodiment of the invention, including both a hexagonal external
tool engagement
surface and a hexagonal internal tool engagement surface.
S Figure 14 is a side view and an end view of a solid retaining pin according
to a
preferred embodiment of the invention, including both a square external tool
engagement
surface and a square internal tool engagement surface.
Figure 15 is a side view and an end view of an integrated retainer component
according to a preferred embodiment of the invention, including a hexagonal
external tool
engagement surface, a circular retaining washer and a shear plane comprising a
groove with a
profile in the shape of an asymmetrical truncated cone.
Figure 16 is a side view and an end view of an integrated retainer component
according to a preferred embodiment of the invention, including a hexagonal
external tool
engagement surface, a circular retaining washer and a shear plane comprising a
region of
shearable thickness in the retaining washer.
Figure 17 is a side view and an end view of an integrated retainer component
according to a preferred embodiment of the invention, including a hexagonal
retaining washer
and a shear plane comprising a region of shearable thickness in the retaining
washer.
Figure 18 is a side view and an end view of an integrated retainer component
according to a preferred embodiment of the invention, including a square
retaining washer and
a shear plane comprising a region of shearable thickness in the retaining
washer.
Figure 19 is a side view and an end view of an integrated retainer component
according to a preferred embodiment of the invention, including a hexagonal
external tool
engagement surface, a circular retaining washer and a shear plane comprising
an overall
shearable thickness of the retaining washer.
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Figure 20 is a side view and an end view of an integrated retainer component
according to a preferred embodiment of the invention, including a hexagonal
retaining washer
and a shear plane comprising an overall shearable thickness of the retaining
washer.
Figure 21 is a side view and an end view of an integrated retainer component
according to a preferred embodiment of the invention, including a square
retaining washer and
a shear plane comprising an overall shearable thickness of the retaining
washer.
Figure 22 is a side view of a first member and a second member which have
been modified to facilitate use of an integrated retainer component according
to a preferred
embodiment of the invention.
Figure 23 is a transverse partial section view of the first member and the
second
member of Figure 22 taken along Section C - C from Figure 22.
DETAILED DESCRIPTION
Preferred embodiments of the invention are depicted in Figure 1 to Figure 21.
Figure 1 to Figure 12 depict a first set of embodiments. Figure 13 to Figure
21 depict
components of a second set of embodiments. Figure 22 and Figure 23 depict
modifications to a
first member and a second member which have been made to accommodate the
embodiments
of the invention depicted in Figure 13 to Figure 21.
The embodiments depicted in Figure 1 to Figure 21 are intended only to provide
illustration of specific preferred applications of various features of the
invention. Many of the
features of the invention are applicable through a wide range of embodiments,
all within the
scope of the invention. In the Figures and in the description that follows,
common reference
numbers are used to describe elements which are common to the various
embodiments.
Referring to Figure 1, a retaining pin assembly (20) is shown in an assembled
configuration in which a first member consisting of an adapter (22) is in a
connecting
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configuration with a second member consisting of a tooth (24) for a piece of
earthworking
equipment (not shown).
Referring to Figure 2, the retaining pin assembly (20) is depicted in the
assembled configuration. The retaining pin assembly (20) includes a retaining
pin (26), a
retaining washer (28) and a fastener (30) for fastening the retaining washer
(28) to the retaining
pin (26).
Referring to Figure 2, the tooth (24) includes a pair of sidewalls (32) which
straddle the adapter (22) and provide a member interface (34) between the
adapter (22) and
each of the sidewalk (32). The adapter (22) includes a transverse bore (36)
and each of the
sidewalk (32) includes an aperture (38). A recess (40) is defined by the
adapter (22) adjacent
to one of the member interfaces (34). The transverse bore (36), the apertures
(38) and the
recess (40) are all substantially in axial alignment.
The retaining pin (26) is positioned in the transverse bore (36) such that a
bore
interface (42) is provided between the retaining pin (26) and the transverse
bore (36). The
retaining pin assembly (20) in the assembled configuration has an assembled
length (44). The
assembled length (44) is greater than the distance between the member
interfaces (34) so that
the retaining pin assembly (20) protrudes into each of the apertures (38),
thus preventing the
tooth (24) from separating from the adapter (22).
The retaining pin (26) has a first end (46) and a second end (48). Referring
to
Figure 3 and Figure 4, a socket section (50) of the retaining pin (22) is
provided adjacent to the
first end (46) of the retaining pin (26). The socket section (50) includes pin
threads (52) and a
pin shoulder (54). The socket section (50), including the pin threads (52) and
the pin shoulder
(54), are designed to be complementary with corresponding structures on the
fastener (30).
The retaining pin (26) preferably defines a longitudinal bore (56) and is
therefore
preferably hollow along its length in order to prevent the accumulation of
debris in the socket
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section (50), which debris could interfere with the assembly and disassembly
of the retaining
pin assembly (20). The longitudinal bore (56) includes the socket section
(50).
A tool engagement surface (58) is provided adjacent to the second end (48) of
the retaining pin (26). The tool engagement surface (58) facilitates gripping
of the retaining pin
(26) by a tool (not shown) during assembly and disassembly of the retaining
pin assembly (20).
Preferably the tool engagement surface (58) is designed to accommodate a
socket or a wrench
and is preferably comprised of either a square surface as in Figure 3 or a
hexagonal surface as in
Figure 4.
The purpose of the fastener (30) is to fasten the retaining washer (28) to the
retaining pin (26). The fastener (30) is preferably a removable fastener, but
the fastener (30)
could also permanently fasten the retaining washer (28) to the retaining pin
(26). If the fastener
(30) is a removable fastener, then a shearing mechanism such as described
below is optional. If
the fastener (30) is non-removable, then a shearing mechanism as described
below or some
other disassembly mechanism will be required.
In the embodiments of Figure 1 to Figure 21, the fastener (30) and the
retaining
pin (26) together provide a threaded connection so that the retaining pin (26)
is comprised of
the pin threads (52) and the fastener (30) is comprised of a bolt (60) having
complementary
fastener threads (62). The retaining pin assembly (20) may be designed so that
the pin threads
(52) are either external threads or internal threads.
In the embodiment of Figure 1 to Figure 12 where the retaining pin (26) is
comprised of the socket section (50), the pin threads (52) are internal
threads which line the
socket section (SO) and the fastener threads (62) are external threads.
Refernng to Figure 5 and Figure 6, the bolt (60) is comprised of a plug
section
(64), a head section (66) and a washer mounting section (68) which is between
the plug section
(64) and the head section (66). In addition, the fastener threads (62) are
comprised of external
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threads on the plug section (64) of the bolt (60) and the bolt (60) is further
comprised of a
fastener shoulder (70).
The pin threads (52) and the fastener threads (62) engage each other to
provide
the threaded connection between the bolt (60) and the retaining pin and the
pin shoulder (54)
and the fastener shoulder (70) engage each other to limit the travel of the
bolt (60) within the
retaining pin (26) and thus define the assembled configuration of the
retaining pin assembly
(20).
The head section (66) of the bolt (60) is provided with a tool engagement
surface
(72) so that the fastener (30) may be engaged by a tool (not shown).
Preferably the tool
engagement surface (58) on the retaining pin (26) is similar or identical to
the tool engagement
surface (72) on the fastener (30). For example, the tool engagement surface
(72) on the bolt
(60) may be comprised of a hexagonal surface as in Figure S or a square
surface as in Figure 6.
The retaining washer (28) is designed to be fastened to the retaining pin (26)
with the fastener (30). Referring to Figure 2, in the assembled configuration
of the embodiment
of Figure 1 to Figure 12 the retaining washer (28) is positioned on the washer
mounting section
(68) of the bolt (60) and is also positioned within the recess (40). More
particularly the
retaining washer (28) is held between the head section (66) of the bolt (60)
and the retaining pin
(26) when the bolt (60) and the retaining pin (26) are fastened together.
The purpose of the retaining washer (28) is to restrain axial movement of the
retaining pin (26) and thus prevent the tooth (24) from separating from the
adapter (22). As a
result, the retaining washer (28) should have a diameter which is adapted to
be greater than both
the diameter of the transverse bore (36) and the diameter of the aperture (38)
which is adjacent
to the recess (40) when the tooth (24) and the adapter (22) are in the
connecting configuration.
The retaining washer (28) defines a washer bore (74) so that the retaining
washer
(28) can be mounted on the washer mounting section (68) of the bolt (60). In
order that the
retaining washer (28) can remain in fixed axial position relative to the
retaining pin (26), the
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diameter of the washer bore (74) is preferably less than the outer diameter of
the retaining pin
(26) and the diameter of the washer bore (74) is also preferably less than the
diameter of the
head section (66) of the bolt (60).
Where the fastener (30) is a removable fastener, it is intended during normal
use
of the retaining pin assembly (20) that each of the retaining pin (26), the
retaining washer (28)
and the fastener (30) may be reused. Where the fastener (30) is a non-
removable fastener or
where the fastener (30) becomes stuck, it is either necessary or desirable
that a backup
disassembly mechanism be provided for the retaining pin assembly (20). The use
of this
backup disassembly mechanism may result in damage to or destruction of one or
more of the
parts of the retaining pin assembly (20).
In preferred embodiments of the invention, the backup disassembly mechanism
is provided by modifying the retaining washer (28) to provide a shearing
mechanism such that
the retaining washer (28) defines a shear plane (75) for shearing of the
retaining washer (28).
Referring to Figure 2 and to Figures 7 - 12, the shear plane (75) is
preferably
comprised of a groove (76) in the retaining washer (28) which provides a
region or area of the
retaining washer (28) which has a shearable thickness which is relatively easy
to shear upon the
application of an axial driving force to either the retaining pin (26) or to
the bolt (60).
In the embodiment of Figure 1 to Figure 12, the groove (76) is generally
coincident with the bore interface (42) and is thus an annular shaped groove.
This
configuration enables the retaining pin (26) to be removed from the transverse
bore (36) from
either side of the adapter (22). Alternatively, the groove (76) may be
coincident with the
diameter of the aperture (38) which is adjacent to the recess (40), in which
case it would be
possible only to remove the retaining pin (26) from the transverse bore (36)
in one direction.
In any event, the shearing mechanism must provide a shear eccentricity in
which
an applied shear force and the reaction shear force are applied on opposite
sides of the groove
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CA 02455314 2004-O1-19
(76). Refernng to Figure 12, an illustration is provided of shear eccentricity
resulting from the
application of an axial driving force to either the retaining pin (26) or to
the bolt (60).
The retaining washer (28) may be designed to shear at a particular applied
driving force by considering both the shape of the profile of the groove (76)
and the depth of
the groove (76). The shape of the profile of the groove (76) is preferably
also designed to
provide maximum tolerance to accommodate "play" or lateral movement of the
retaining pin
assembly (20) relative to the transverse bore (36). Referring to Figures 7 -
11, exemplary
shapes for the profile of the groove (76) are provided. In the embodiment as
depicted in Figure
2 and Figure 12 the shape of the profile of the groove (76) is comprised of a
symmetrical
truncated cone.
In operation, the retaining pin assembly (20) of the embodiments of Figure 1
to
Figure 12 may be assembled as follows. First, the retaining washer (28) is
positioned in the
recess (40). Second, the tooth (24) and the adapter (22) are positioned in the
connecting
configuration so that the transverse bore (36) and the apertures (38) are in
substantial
alignment. Third, one of the retaining pin (26) and the fastener (30) is
inserted in the transverse
bore (36). Fourth, the other of the retaining pin (26) and the fastener (30)
is inserted in the
transverse bore (36) and the fastener (30) is connected with the retaining pin
(26) to fasten the
retaining washer (28) to the retaining pin (26). The fastener (30) is
connected with the retaining
pin (26) by making up the threaded connection between the bolt (60) and the
retaining pin (26).
Where the retaining pin (26) is hollow, debris which is present in the socket
section (50) of the retaining pin (26) will be forced by the bolt (60) through
the longitudinal
bore (56) of the retaining pin (26) during assembly of the retaining pin
assembly (20) so that the
debris does not interfere with the assembly of the retaining pin assembly
(20).
In operation, the retaining pin assembly (20) of the embodiments of Figure 1
to
Figure 12 may be disassembled as follows. First, the fastener (30) is
disconnected from the
retaining pin (26). The fastener (30) is disconnected from the retaining pin
(26) by breaking
down the threaded connection between the bolt (60) and the retaining pin (26).
Alternatively,
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CA 02455314 2004-O1-19
an axial driving force may be applied to the retaining pin (26) or to the bolt
(60) to shear the
retaining washer (28). Second, the retaining pin (26) is removed from the
transverse bore (36).
Third, the tooth (24) is separated from the adapter (22). Fourth, the
retaining washer (28) is
removed from the recess (40).
The retaining pin (26) and the bolt (60) are preferably reused unless they are
damaged. The retaining washer (28) may either be discarded or reused,
depending upon
whether it has been sheared during disassembly of the retaining pin assembly
(20).
Where, as described above with respect to Figure 1 to Figure 12, the retaining
pin assembly (20) includes the retaining pin (26), the retaining washer (28)
and the fastener (30)
as separate parts, the retaining pin assembly (20) may be used with little or
no modification of
the adapter (22) and/or the tooth (24). Typically, the only modification which
may be required
is the machining, casting or forging of the recess (40) in the adapter (22)
and/or the tooth (24),
if the recess (40) is not already provided.
Figure 13 to Figure 21 depict components of a second set of embodiments of the
retaining pin assembly (20) and depict variations in features of the retaining
pin assembly (20)
which may be applicable to other embodiments of the invention, including the
embodiments of
Figure 1 to Figure 12.
The use of the embodiments depicted in Figure 1 to Figure 21 may require
modification of either or both of the adapter (22) and the tooth (24). One
example of such
modification is depicted in Figure 22.
Refernng to Figure 13 and Figure 14, the retaining pin (26) is solid and is
comprised of a plug section (78). The plug section (78) is located at the
first end (46) of the
retaining pin (26).
The retaining pin (26) also comprises the tool engagement surface (58), which
is
located adjacent to the second end (48) of the retaining pin (26). In Figure
13 the tool
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CA 02455314 2004-O1-19
engagement surface (58) is comprised of both an external hexagonal surface for
engaging a
socket or wrench and an internal hexagonal surface for engaging an Allen
wrench or similar
tool. In Figure 14 the tool engagement surface (58) is comprised of both an
external square
surface for engaging a socket or wrench and an internal square surface for
engaging a
screwdriver, wrench or similar tool. It is not necessary to include both
external and internal
tool engagement surfaces (58) on the retaining pin (26), but there may be
advantages to doing
so.
The plug section (78) of the retaining pin (26) includes pin threads (52)
which
are external threads. The plug section (78) of the retaining pin (26) also
comprises the pin
shoulder (54).
Referring to Figure 15 to Figure 21, various embodiments of an integrated
retainer component (80) are depicted. The integrated retainer component (80)
is preferably
forged from a single piece of a suitable material such as steel. The
integrated retainer
component (80) comprises both the retaining washer (28) and the fastener (30).
The fastener
(30) in Figure 15 to Figure 21 is comprised of a nut (82) which is compatible
with the plug
section (78) of the retaining pin (26). The nut (82) includes fastener threads
(62). The fastener
threads (62) are internal threads which are complementary with the pin threads
(52). The
fastener (30) is further comprised of the fastener shoulder (70) which is
configured to engage
the pin shoulder (54) on the retaining pin (26).
Alternatively, if the retaining pin (26) defines a socket section (50) as in
the
embodiments of Figure 1 to Figure 12, the fastener (30) of the integrated
retainer component
(80) may be comprised of a bolt, screw or other suitable externally threaded
component. In
either case, the retaining washer (28) defines the washer bore (74).
As depicted in Figure 15, Figure 16 and Figure 19, the retaining washer (28)
has
a peripheral shape which is round, resulting in the possibility that the
integrated retainer
component (80) may be capable of rotation relative to the recess (40) when the
retaining pin
assembly (20) is in the assembled configuration. Consequently, the integrated
retainer
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CA 02455314 2004-O1-19
component (80) of Figure 15, Figure 16 and Figure 19 preferably comprises the
tool
engagement surface (72) so that the fastener (30) can be engaged by a tool
(not shown). Where
the fastener (30) is a nut (82) or similar device as in Figure 15 to Figure
21, the tool
engagement surface (72) is preferably an external surface so that the internal
fastener threads
(62) can be accommodated.
As depicted in Figure 17, Figure 18, Figure 20 and Figure 21, the retaining
washer (28) is comprised of a recess engaging surface (84) which is adapted to
engage the
recess (40) in order to inhibit rotation of the integrated retainer component
(80) relative to the
recess (40). In Figure 17 and Figure 20 the recess engaging surface (84) is a
hexagonal surface.
In Figure 18 and Figure 21 the recess engaging surface (84) is a square
surface. In the
embodiments of integrated retainer component (80) depicted in Figure 17,
Figure 18, Figure 20
and Figure 21 the recess (40) is configured to be complementary with the
recess engaging
surface (84).
The retaining washer (28) in each of the embodiments of the integrated
retainer
component (80) depicted in Figure 15 to Figure 21 is comprised of the shear
plane (75) which
will facilitate shearing of the retaining washer (28) in the event that the
fastener (30) cannot be
disconnected from the retaining pin (26) during disassembly of the retaining
pin assembly (20).
In Figure 15 the shear plane (75) is comprised of the groove (76) in the
retaining
washer which provides a region of shearable thickness in the retaining washer
(28). As
depicted in Figure 15 the groove (76) is adapted to be generally coincident
with the bore
interface (42) when the retaining pin assembly (20) is in the assembled
configuration and
includes a profile having the shape of an asymmetrical truncated cone.
In Figure 16, Figure 17 and Figure 18 the shear plane (75) is comprised of a
region of shearable thickness which is not in the configuration of a groove
but is instead a
circular area of reduced thickness formed in the retaining washer (28). The
region of shearable
thickness as depicted in Figure 16, Figure 17 and Figure 18 is adapted to
overlap with the bore
interface (42) when the retaining pin assembly (20) is in the assembled
configuration.
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CA 02455314 2004-O1-19
In Figure 19, Figure 20 and Figure 21 the shear plane (75) is comprised of an
overall shearable thickness of the retaining washer (28) so that the retaining
washer (28) is
relatively thin.
The use of the integrated retainer component (80) which combines the retaining
washer (28) and the fastener (30) into a single component may require some
modification to be
made to either or both of the adapter (22) and the tooth (24) to facilitate
assembly of the
retaining pin assembly (20). The reason for this is that the fastener (30)
will typically be
designed to extend outward from the adapter (22) past the member interface
(34) when the
retaining pin assembly (20) is in the assembled configuration.
As a result, where the integrated retainer component (80) is provided, the
assembly of the retaining pin assembly (20) will require that the adapter (22)
and the tooth (24)
be placed in the connecting configuration before the retaining washer (28) is
positioned in the
recess (40). This in turn will require that a structure or mechanism be
provided to enable the
retaining washer (28) to be positioned in the recess (40) when the adapter
(22) and the tooth
(24) are in the connecting configuration. Any suitable structure or mechanism
may be utilized
which facilitates both the assembly and disassembly of the retaining pin
assembly (20) and
which facilitates the functioning of the retaining pin assembly (20) while it
is assembled.
Referring to Figure 22 and Figure 23, a preferred modification to the adapter
(22) and the tooth (24) is depicted. A groove (86) is provided in an interior
surface (92) of the
tooth (24) which extends from an open end (88) of the tooth (24) to the
aperture (38). The
groove (86) accommodates the fastener (30) during assembly of the retaining
pin assembly (20).
The groove (86) is preferably sized to be only slightly wider than the
diameter of the fastener
(30).
A corresponding groove (90) is provided along an exterior surface (93) of the
adapter (22). The groove (90) accommodates the retaining washer (28) during
assembly of the
retaining pin assembly (20). Alternatively, the groove (90) could be provided
along the interior
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CA 02455314 2004-O1-19
surface (92) of the tooth (24) or alternatively the adapter (22) and the tooth
(24) could be
designed to provide sufficient clearance between them to accommodate the
retaining washer
(28) without providing the groove (90). Where provided, the groove (90) is
preferably sized to
be only slightly wider than the diameter of the retaining washer (28).
Instead of the groove (86), the tooth (24) could be provided with a slot (not
shown) extending through the tooth (24) for accommodating the fastener (30).
In addition,
instead of providing the groove (90) for accommodating the retaining washer
(28) in one of the
interior surface (92) of the tooth (24) and the exterior surface (93) of the
adapter (22), the
groove (90) may be provided in both the interior surface (92) of the tooth
(24) and the exterior
surface (93) of the adapter (22).
The groove (86) or slot (not shown) for accommodating the fastener (30) and
the
groove (90) for accommodating the retaining washer (28) may be configured in
any manner
1 S which facilitates moving the retaining washer (28) into position in the
recess (40).
Referring to Figure 22, the groove (86) and the groove (90) are, however,
preferably configured to approach and encounter the aperture (38) in a
straight line in order to
simplify the task of moving the retaining washer (28) into position in the
recess (40).
As a result, in the embodiment depicted in Figure 22, the groove (86) and the
groove (90) extend in a straight line from the open end (88) of the tooth (24)
to the aperture
(38), but alternative conf gurations are possible. As one alternative
configuration, the groove
(86) and the groove (90) may extend in a straight line from a bottom end (94)
of the tooth (24)
to the aperture (38), but this configuration will require further modification
of the tooth (24) to
provide an aperture (not shown) to facilitate insertion of the retaining
washer (28) into the tooth
(24). As a second alternative configuration, the groove (86) and the groove
(90) may extend in
an L-shape (or some other shape) from the open end (88) of the tooth (24) to
the aperture (38),
but this configuration may complicate the task of moving the retaining washer
(28) into
position in the recess (40)
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CA 02455314 2004-O1-19
In operation, the retaining pin assembly (20) of the embodiments of Figure 13
to
Figure 21 may be assembled as follows in relation to the adapter (22) and the
tooth (24) of
Figure 22 and Figure 23. First, the tooth (24) and the adapter (22) are
positioned in the
connecting configuration so that the transverse bore (36) and the apertures
(38) are in
substantial alignment. Second, the integrated retainer component (80) is
inserted in the groove
(86) and groove (90) and moved to the aperture (38). Third, the retaining pin
(26) is inserted in
the transverse bore (36) and the fastener (30) is connected with the retaining
pin (26) to fasten
the retaining washer (28) to the retaining pin (26). The fastener (30) is
connected with the
retaining pin (26) by making up the threaded connection between the nut (82)
and the retaining
pin (26).
In operation, the retaining pin assembly (20) of the embodiments of Figure 13
to
Figure 21 may be disassembled as follows in relation to the adapter (22) and
the tooth (24) of
Figure 22 and Figure 23. First, the retaining pin (26) is disconnected from
the fastener (30) by
breaking down the threaded connection between the nut (82) and the retaining
pin (26).
Alternatively, an axial driving force may be applied to the retaining pin (26)
or to the nut (82) to
shear the retaining washer (28). Second, the retaining pin (26) is removed
from the transverse
bore (36). Third, if it has not been necessary to shear the retaining washer
(28), the retaining
washer (28) is removed from the recess (40) and the integrated retainer
component (80) is
moved along the groove (86) and the groove (90) and removed from the open end
(88) of the
tooth (24). Alternatively, if it has been necessary to shear the retaining
washer (28), the
fastener (30) may be removed by passing it through the aperture (38), leaving
the retaining
washer (28) positioned in the recess (40). Fourth, the tooth (24) is separated
from the adapter
(22).
The retaining pin (26) is preferably reused unless it is damaged. The
integrated
retainer component (80) may either be discarded or reused, depending upon
whether the
retaining washer (28) has been sheared during disassembly of the retaining pin
assembly (20).
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