U.S. patent application number 12/465851 was filed with the patent office on 2009-11-19 for pocket protecting retainable cutter bit.
Invention is credited to Luis Miguel Porturas, Richard Wayne Watson.
Application Number | 20090284069 12/465851 |
Document ID | / |
Family ID | 41315482 |
Filed Date | 2009-11-19 |
United States Patent
Application |
20090284069 |
Kind Code |
A1 |
Watson; Richard Wayne ; et
al. |
November 19, 2009 |
Pocket Protecting Retainable Cutter Bit
Abstract
Pocket protecting retainable cutter bits used on various mining,
excavating, and foundation drilling tools and equipment are
disclosed. The invention includes a combination of one or more free
spinning wear rings axially mounted in recessed portions of the
cutter bit shank and a groove and snap ring retainer. The wear
rings are tapered on at least one end to assist in installation and
designed to compress as the cutter bits are installed into cutter
bit pockets. These wear rings are designed to protect the inside
surface of the pocket by acting as a barrier between the spinning
cutter bit and the stationary inside surface of the pocket. The
cutter bit shank is longer than the cutter bit pocket and when
installed passes through the pocket and extends past the axial
length of the pocket. A flange is included with the cutter bit to
protect the outer surface of the pocket.
Inventors: |
Watson; Richard Wayne;
(Lakeside, CA) ; Porturas; Luis Miguel; (Lakeside,
CA) |
Correspondence
Address: |
ERIC HANSCOM
7395 PORTAGE WAY
CARLSBAD
CA
92011
US
|
Family ID: |
41315482 |
Appl. No.: |
12/465851 |
Filed: |
May 14, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61054150 |
May 18, 2008 |
|
|
|
Current U.S.
Class: |
299/10 ;
299/104 |
Current CPC
Class: |
E21C 35/197
20130101 |
Class at
Publication: |
299/10 ;
299/104 |
International
Class: |
E21C 35/197 20060101
E21C035/197 |
Claims
1. A cutter bit comprising a relieved shank surface, a retaining
shoulder, and a split wear ring, where the split wear ring is
axially mounted to and substantially surrounds the relieved shank
surface, where the split wear ring has a resting outer diameter,
where the retaining shoulder has an outer diameter, where the
resting outer diameter of the split wear ring is greater than the
outer diameter of the retaining shoulder.
2. The cutter bit of claim 1, further comprising a snap ring shaft
and a snap ring groove, where the snap ring shaft has an outer
diameter, where the outer diameter of the snap ring shaft is less
than the outer diameter of the retaining shoulder.
3. The cutter bit of claim 1, further comprising a flange.
4. The cutter bit of claim 3, where the flange has an outer
diameter, where the outer diameter of the flange is greater than
the resting outer diameter of the split wear ring.
5. The cutter bit of claim 1, where the split wear ring comprises a
tapered edge, where the tapered edge is adjacent to the retaining
shoulder.
6. The cutter bit of claim 1, additionally comprising an additional
split wear ring.
7. A cutter bit system comprising a cutting bit and a pocket, where
the cutter bit comprises a relieved shank surface, a retaining
shoulder, and a split wear ring, where the split wear ring is
axially mounted to and substantially surrounds the relieved shank
surface, where the split wear ring has a resting outer diameter,
where the retaining shoulder has an outer diameter, where the
resting outer diameter of the split wear ring is greater than the
outer diameter of the retaining shoulder, where the split wear ring
can be compressed thereby reducing its outer diameter, where the
pocket has an inner surface, where the inner surface of the pocket
has a first inner diameter that is greater than the outer diameter
of the retaining shoulder of the cutter bit and less than the
resting outer diameter of the split wear ring.
8. The cutter bit system of claim 7, where the cutter bit relieved
shank surface, retaining shoulder, and split wear ring are secured
within the inner surface of the pocket.
9. The cutter bit system of claim 7, where the cutter bit further
comprises a snap ring shaft and a snap ring groove, where the snap
ring shaft has an outer diameter, and where the inner surface of
the pocket has a second inner diameter that is less than the first
inner diameter, where the second inner diameter is greater than the
outer diameter of the snap ring shaft.
10. The cutter bit system of claim 9, where the cutter bit further
comprises a snap ring, where the snap ring secures the cutter bit
to the pocket.
11. The cutter bit system of claim 7, where the cutter bit further
comprises a flange, where the flange has an outer diameter, where
the outer diameter of the flange is greater than the resting outer
diameter of the split wear ring.
12. The cutter bit system of claim 11, where the outer diameter of
the flange is greater than the first inner diameter of the
pocket.
13. The cutter bit system of claim 7, where the split wear ring
comprises a tapered edge, where the tapered edge is adjacent to the
retaining shoulder.
14. A method of using a cutter bit comprising the steps of
obtaining a cutter bit, where the cutter bit comprises a relieved
shank surface, a retaining shoulder, a flange, and a split wear
ring, where the split wear ring is axially mounted to and
substantially surrounds the relieved shank surface, where the split
wear ring has a resting outer diameter, where the retaining
shoulder has an outer diameter, where the resting outer diameter of
the split wear ring is greater than the outer diameter of the
retaining shoulder, where the split wear ring can be compressed
thereby reducing its outer diameter, where the flange has an outer
diameter, inserting the relieved shank surface, retaining shoulder,
and split wear ring of the cutter bit into a pocket, where the
pocket is secured to a host tool, securing the cutter bit to the
pocket, using the host tool with the pocket and cutter bit to
dislodge and/or break apart material where the pocket has an inner
surface, where the inner surface of the pocket has a first inner
diameter that is greater than the outer diameter of the retaining
shoulder of the cutter bit and less than the resting outer diameter
of the split wear ring, where the outer diameter of the flange is
greater than the first inner diameter of the pocket.
15. The method of claim 14, where the insertion of the cutter bit
into the pocket causes the split wear ring to compress.
16. The method of claim 14, where the split wear ring has an inner
diameter, where the relieved shank surface has an outer diameter,
where the inner diameter of the split wear ring after insertion
into the pocket is greater than the outer diameter of the relieved
shank surface.
17. The method of claim 14, where the cutter bit rotates relative
to the pocket during use, and where the relieved shank surface
rotates relative to the split wear ring, thereby reducing the
wearing of the inner surface of the pocket from the rotation of the
cutter bit.
18. The method of claim 14, where the cutter bit further comprises
a snap ring shaft and a snap ring groove, where the snap ring
groove in conjunction with a snap ring secures the cutter bit to
the pocket.
19. The method of claim 14, where the split wear ring comprises a
tapered edge, where the tapered edge is adjacent to the retaining
shoulder, where the tapered edge aids in the insertion of the split
wear ring into the pocket.
20. The method of claim 14, further comprising the step of removing
the cutter bit from the pocket.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This Patent Application is a nonprovisional of U.S. Patent
Application No. 61/054,150 filed on May 18, 2008, the entirety of
which is hereby incorporated by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] This invention was not federally sponsored.
BACKGROUND OF THE INVENTION
Field of the invention
[0003] This invention relates to the general field of drilling, and
more specifically toward pocket protecting retainable cutter bits
used on various mining, excavating, and foundation drilling tools
and equipment. The goal of the current invention is to prevent the
common problems associated when using said equipment, specifically
the wear of cutter bit pockets and the loss of cutter bits. The
invention is a combination of one or more free spinning wear rings
axially mounted in recessed portions of the cutter bit shank and a
groove and snap ring retainer. The wear rings are designed to
compress as the cutter bits are installed into cutter bit pockets.
These wear rings are designed to protect the inside surface of the
pocket by acting as a barrier between the spinning cutter bit and
the stationary inside surface of the pocket. The wear rings can be
made of wear resistant materials, preferably hardened metal,
although it is envisioned that hard plastic, graphite, composite
materials, and rubber could be used. These wear rings are split
lengthwise to allow them to compress when inserted into the cutter
bit pockets. The wear rings are tapered on at least one end to
assist alignment and installation into cutter bit pockets. The
cutter bit shank is longer than the cutter bit pocket and when
installed passes through the pocket and extends past the axial
length of the pocket. A radial snap ring groove is cut into the
exposed end of the cutter bit shank and when a snap ring is
installed provides a failsafe method of retention.
[0004] While digging and excavating has occurred throughout ancient
times, it was only in the early 1900s that Howard Hughes invented
the first carbide roller bits. These bits dramatically improved
production and have since undergone substantial improvements in
technology. While improvements have been made in the field of
cutting tools and equipment, a major problem has remained unsolved:
when using heavy equipment there is a massive amount of abrasion
and wear that occurs and most of the wear and subsequent damage
occurs at the cutter bits and the pockets that hold them in place.
Cutter bits are designed to spin inside the pockets that hold them
so both the cutter bits and the pockets will wear evenly as they
cut through dirt and rock. The problem is that while the cutter
bits spin they wear out the inside surface of the pockets that hold
them in place. Cutter bits are usually easy to replace when worn
out, but the pockets are difficult and time consuming to replace
because they are usually set at specific cutting angles and are
welded into place.
[0005] The prior art has several examples of attempts to resolve
the problem, including the inventions of U.S. Pat. No. 4,844,550 to
Beebe, U.S. Pat. Nos. 5,088,797 and 5,302,005 to O'Neill, and U.S.
Pat. No. 5,628,549 to Ritchey, et al. These patents attempt to
reduce wear, but in reality, mainly serve to hold the cutter bit
inside the pocket with spring loaded friction. Because the wear and
tear on the cutter bits is quite substantial, the use of prior art
devices have continued to result in high friction between the
cutter bit and the pocket thereby producing heat and mechanical
grinding between the cutter bit and pocket with a corresponding
loss of holding power. The prior art also contains cutter bits with
dual retainer systems. The main problem with these products is that
they do not protect both the inside and outside of the pocket. The
current invention solves this problem by providing a cutter bit
with a substantial flare, or flange, that protects both the inside
and the outside of the pocket.
[0006] These references have proven to be ineffective in numerous
situations as cutting tools experience normal use vibrations and
impacts. These vibrations and impacts often loosen the spring
loaded rings and compromise their holding power. Subsequently,
cutter bits frequently fall out of their pockets causing immediate
damage to the unprotected surfaces of host tools. Tool repairs and
loss of production are prevalent especially when excavating hard
and highly abrasive materials. The prior art also teaches loose
wear parts that need to be installed and removed before and after
installing and removing cutter bits. These extra steps require more
time and effort, and any replacement of a cutter bit also presents
the possibility of injury or death to the mechanic. The machines
that use cutter bits to bore into the ground are quite large and
powerful, and a standard augur can weigh several tons, thereby
creating an inherently dangerous situation whenever a worker is
called upon to replace a cutter bit or perform other maintenance on
the machine.
[0007] It is also noteworthy that by increasing the lifespan of a
cutter bit and reducing the number of serviceable parts, the
invention decreases the frequency and cost with which welders have
to work upon the machines. This is beneficial in several ways.
First, welding on a machine is an inherently dangerous activity.
The less frequently welding has to be done, the lower the risk of
injury and death. Second, qualified welders can be expensive. Thus,
a user of the invention will pay less than would a company using
the prior art cutter bits since less welding will be required.
Third, having a machine out of service can cost the company that
owns the machine several thousand dollars for each day of
inactivity. In remote locations where it is not feasible to weld,
the machine may have to be removed from the worksite and
transported to a more convenient location--all for a $50 cutter
pocket. Obviously it is highly beneficial to have machines stay out
on the job for longer periods of time, and having a cutter bit
which protects both the inside and outside of the pocket, is easily
replaced, and decreases the frequency with which the pockets need
to be replaced.
[0008] Thus there has existed a long-felt need for a cutter bit
that can protect both the inside and outside of the pocket, ensure
failsafe retention and be easy to install and replace. The current
invention provides such a solution by having a pocket-protecting
and retainable cutter bit that is easy to install and replace, the
goal of which is to prevent the common problems associated when
using excavating equipment, specifically the wear of cutter bit
pockets and the loss of cutter bits through its unique flange shape
and wear rings. The invention includes a combination of one or more
free spinning wear rings axially mounted in recessed portions of
the cutter bit shank and a snap ring retainer groove. The wear
rings are designed to compress as the cutter bits are installed
into cutter bit pockets. These wear rings are designed to protect
the inside surface of the pocket by acting as a barrier between the
spinning cutter bit and the stationary inside surface of the
pocket. The wear rings can be made of abrasion-resistant materials,
preferably hardened metal, oil impregnated bronze, or other
self-lubricating material. These wear rings are split lengthwise to
allow them to compress when inserted into the cutter bit pockets.
The wear rings are tapered on at least one end to assist alignment
and installation into cutter bit pockets. The cutter bit shank is
longer than the cutter bit pocket and when installed passes through
the pocket and extends past the axial length of the pocket. A
radial snap ring groove is cut into the exposed end of the cutter
bit shank and when a snap ring is installed provides a failsafe
method of retention.
SUMMARY OF THE INVENTION
[0009] It is a principal object of the invention to provide a new
pocket protecting, retainable cutter bit by which a cutter bit
manufacturer or consumer can extend the life and value of their
tooling and avoid costly and time consuming replacement of lost
cutter bits and worn cutter bit pockets. These cutter bits can be
made in many different shapes and sizes to protect the inside and
outside of the pocket depending on the material being cut and
excavated.
[0010] It is another object of the invention to reduce the need to
replace lost cutter bits by providing a failsafe retention
method.
[0011] It is an additional object of the invention that the cutter
bit will have the wear rings pre-installed on its shank to make it
easy to install and remove from pockets.
[0012] It is a further object of the invention that the cutter bit
will have one or more wear rings depending on the shape of the
pocket.
[0013] It is also an object of the invention that the wear rings
can be made in various shapes to protect more than one surface at a
time.
[0014] It is an additional object of the invention that the wear
rings be made of wear resistant materials such as hardened steel,
self lubricated oil impregnated bronze, or others that prevent wear
and reduce friction.
[0015] It is also an object of this invention that the wear rings
will be split lengthwise to allow their bodies to compress not only
for ease of manufacturing, but also to allow for the wear rings to
compress when installed in the pockets.
[0016] It is also an object of this invention to accommodate many
different tooth shapes and sizes in order to cut various types of
materials.
[0017] It is a further object of the invention to provide a cutter
bit that protects both the inside and outside of the pocket.
[0018] It is another object of this invention to provide a cutter
bit that does not require a separated wear sleeve; rather it is
self contained within the cutter bit and protects the pocket
without the use of a separate device such as a sleeve.
[0019] It is a final object of this invention to provide a cost
effective solution that is easy to manufacture and use in the
field.
[0020] The current invention provides a cutter bit that protects
and reduces wear of the inner and outer surfaces of the pocket. The
flange of the cutter bit protects the outer surfaces of the pocket
while the split wear ring of the cutter bit allows the cutter bit
to rotate within the pocket while reducing wear on the inner
surface of the pocket. Prior art teaches using multiple devices to
ineffectively reach the same goal, such as cutter bits with one or
more sleeves that are separately inserted into the pocket, whereby
the sleeves must also be replaced as they are worn down.
[0021] The cutter bit of the current invention enables more
efficient maintenance of drilling tools. Instead of installing and
maintaining a cutter bit and a sleeve, the current invention only
requires the cutter bit. The cutter bit itself is easily installed
and replaced. The cutter bit shank is inserted into the pocket
until it protrudes through the other side and then is locked in
place using a snap-ring or other comparable means. Removal of the
cutter bit is just as easy, whereby a user can remove the cutter
bit by removing the snap-ring and then forcing the cutter bit out
of the pocket. In desolate areas where maintenance is difficult,
the current invention enables users to quickly, easily, and
efficiently replace cutter bits without separately maintaining
sleeves and while reducing wear on the pockets.
[0022] There has thus been outlined, rather broadly, the more
important features of the invention in order that the detailed
description thereof may be better understood, and in order that the
present contribution to the art may be better appreciated. There
are additional features of the invention that will be described
hereinafter and which will form the subject matter of the claims
appended hereto. The features listed herein and other features,
aspects and advantages of the present invention will become better
understood with reference to the following description and appended
claims. The accompanying drawings, which are incorporated in and
constitute part of this specification, illustrate embodiments of
the invention and, together with the description, serve to explain
the principles of the invention.
BRIEF DESCRIPTION OF THE FIGURES
[0023] FIG. 1 is a bottom perspective view of an auger, or host
tool, with a plurality of cutter bits retained in pockets according
to the current invention.
[0024] FIG. 2 is a side perspective view of a cutter bit according
to the current invention;
[0025] FIG. 3 is a top view thereof;
[0026] FIG. 4 is a side view thereof;
[0027] FIG. 5 is a bottom view thereof;
[0028] FIG. 6 is a far side view thereof;
[0029] FIG. 7 is a front view thereof; and
[0030] FIG. 8 is a rear view thereof.
[0031] FIG. 9 is a side view of the cutting bit retained inside of
a pocket.
[0032] FIG. 10 is a side view of another embodiment of invention
where there are two wear rings.
DETAILED DESCRIPTION OF THE FIGURES
[0033] Many aspects of the invention can be better understood with
references made to the drawings below. The components in the
drawings are not necessarily drawn to scale. Instead, emphasis is
placed upon clearly illustrating the components of the present
invention. Moreover, like reference numerals designate
corresponding parts through the several views in the drawings.
[0034] FIG. 1 is a bottom perspective view of a host tool with a
plurality of cutter bits retained in pockets according to the
current invention. Each cutter bit is secured to the host tool
inside of a pocket. The end of the cutter bit opposite of the
flanged tooth extends through the pocket and through to the other
side of the host tool, whereby the portion of the cutter bit that
extends beyond the other side of the host tool includes a snap ring
groove (not shown in this figure) to secure the cutter bit within
the pocket and to the host tool. As the host tool is rotated, the
cutting bits dislodge and break apart the material to be excavated.
Each cutting bit is allowed to rotate within its pocket thereby
causing the cutting bit to wear evenly.
[0035] FIG. 2 is a side perspective view of an embodiment of a
cutter bit according to the current invention. The cutter bit 20
includes a flanged tooth with a tooth 21 and a flange 27. As the
host tool is rotated, the tooth 21 of the cutting bit dislodges and
breaks apart the material to be excavated. The flange 27 of the
flanged tooth protects the front surface of the pocket as the
material is excavated. While a particular style of tooth of 21 is
shown in this and other figures, other styles and shapes are
possible and preferable depending on the material being excavated.
Thus, other style and shapes for the tooth 21 are possible without
departing from the scope of the current invention.
[0036] Next to the flange 27, there is a relieved shank surface 24
around which there is a split wear ring 25. The split wear ring 25
is axially mounted over and substantially surrounds the relieved
shank surface 24 between a retaining shoulder 23 and the flange 27
of the flanged tooth. The split wear ring 25 has a resting outer
diameter that is greater than the outer diameter of the retaining
shoulder 23. A resting outer diameter is the outer diameter of the
object while under no external forces. The pocket that holds the
cutting bit 20 and secures it to the host tool should have an inner
diameter that is slightly larger than the outer diameter of the
retaining shoulder 23, and slightly less than the resting outer
diameter of the split wear ring 25. There is a split in the split
wear ring that allows the ring to compress to a smaller diameter,
allowing it to be close-fitting within the inner wall of the
pocket. When the cutting bit 20 is secured within the pocket, the
split wear ring 25 is in constant contact with the inner surface or
wall of the pocket while the retaining shoulder 23 is not. This
allows the flanged tooth to rotate within the wear ring and prevent
wear on the inner surface of the pocket.
[0037] It should be noted when viewing this figure that should even
one of the many cutter bits fail, the entire machine will be shut
down until the cutter bit is replaced. If it is determined that the
pocket holding the cutter bit has been damaged to the extent that
it has to be replaced, a welder must be brought in to fix the
pocket. Thus, it should be seen that a cutter bit that not only
resists wear better than the prior art, but also protects the
pockets in a far superior manner to the prior art is an extremely
significant improvement in the field. Statistics show that a cutter
bit with a wear ring will last three to five times as long as a
prior art cutter bit, and that a pocket into which only cutter bits
with wear rings have been inserted will last approximately ten
times as long as a pocket that has held prior art cutter bits.
Since the average cutter bit costs around $25, and a pocket costs
around $50 plus at least $250 in labor costs to replace, it should
be obvious that the cost savings alone will be substantial.
[0038] The relieved shank surface 24 rotates against the inner
surface of the split wear ring 25, and thus causes wear against
these two surfaces instead of the inner surface of the pocket. To
aid in the installation of the cutting bit 20 into the pocket, the
split wear ring 25 includes a tapered side 26, which is located on
the side closest to the retaining shoulder 23. As the cutter bit 20
is inserted into the pocket, the tapered side 26 of the split wear
ring 25 comes in contact with the face of the pocket and causes the
split wear ring 25 to compress slightly, thereby allowing the split
wear ring 25 and the remaining portion of the cutter bit 20 to fit
within the pocket up to the flange 27.
[0039] Continuing along the cutter bit 10 and after the retaining
shoulder, there is a snap ring shaft 28 that leads to the snap ring
groove 22. The snap ring grove 22 is designed to extend beyond the
opposing side of the pocket and host tool. This allows a snap ring
to attach around the snap-ring groove 22 to secure the cutter bit
20 within the pocket and to the host tool. While a snap ring groove
22 with a snap ring is a failsafe and preferable method for
retaining the cutter bit within the pocket, other means of securing
the cutter bit within the pocket are possible without departing
from the contemplated scope of the current invention.
[0040] FIG. 3 is a top view of the cutter bit; FIG. 4 is a side
view thereof; FIG. 5 is a bottom view thereof; and FIG. 6 is a far
side view thereof.
[0041] FIG. 7 is a front view of the cutter bit clearly showing the
different diameters of the flange 27 and tooth 21. FIG. 8 is a rear
view of the cutter bit. The flange 27 is clearly shown as well as
the diameters of the split wear ring 25, retaining shoulder 23, and
snap ring shaft 28. As shown in this figure, the resting outer
diameter of the split wear ring 25 is greater than the outer
diameter of the retaining shoulder 23.
[0042] FIG. 9 is a side view of the cutter bit retained inside of a
pocket. The pocket 30 itself is welded inside of the host tool (not
shown in this figure). The pocket preferably has two inner
diameters, a larger inner diameter closer to the tooth of the
cutting bit and a smaller inner diameter further away from the
tooth of the cutting bit. The tooth 21 extends beyond the pocket 30
and is used to dislodge and break apart the material that is to be
excavated. The flange 27 has an outer diameter that is greater than
the proximate inner diameter of the pocket 30 thereby extending
over and protecting at least a portion of the outer surface of the
pocket 30. The split wear ring 25 is secured between the flange 27
and the retaining shoulder 23 on the cutter bit 20. As shown in
this figure, the split wear ring 25 is in close contact with the
inner surface of the pocket 30. While the outer diameter of the
split wear ring 25 is compressed slightly from its resting diameter
to fit within the pocket 30, the inner diameter of the split wear
ring 25 should still be greater than the outer diameter of the
relieved shank surface (not clearly visible in this figure). This
allows for the cutter bit to rotate within the pocket walls 30 and
split wear ring 25, whereby the split wear ring 25 acts as a buffer
between the relieved shank surface and the inner surface of the
pocket 30. The retaining shoulder 23 should have a diameter that is
less than the inner diameter at the location of the inner surface
of the pocket 30 when the cutter bit 20 is secured to the pocket
30. However, because of the shape of the pocket, the retaining
shoulder 23 may nonetheless come in contact with the inner surface
of the pocket 30 from time to time as the cutter bit 20 moves
within the pocket. The outer diameter of the snap ring shaft 28
should also be less than the diameter of the inner surface of the
pocket 30 at that location. While it is preferable that the snap
ring shaft 28 not come in contact with the inner surface of the
pocket 30, it may nonetheless occur during normal operation.
Continuing along the cutter bit 20, after the snap ring shaft 28,
there is the snap ring groove 22 with a snap ring 29 in place. The
snap ring 29 secures around the snap ring groove 22 and has an
outer diameter that is greater than the opening diameter of the
pocket adjacent to it. This configuration prevents the cutter bit
from sliding out of the pocket during normal use. This is a
fail-safe method for retaining the cutter bit to the host tool.
[0043] The split wear ring enables the efficient use of the cutter
bit while reducing the wear on the pocket. The split wear ring
moves relatively little, if at all, in relation to the inner
surface of the pocket. However, the remaining portion of the
cutting bit, including the tooth and relieved shank surface, are
allowed to rotate. This results in a tooth that is worn down more
evenly during use. The relieved shank surface and the split wear
ring will wear down as well, but they wear down at a much lower
rate in most cases than the tooth portion. Most importantly, there
is a significant reduction in wear of the inner surface of the
pocket as the majority of the friction from the rotating cutter bit
occurs between the relieved shank surface and split wear ring.
Therefore, the current invention enables users of the disclosed
cutter bit to easily and effectively have rotating cutter bits that
wear evenly and replace easily while reducing the need to replace
and/or repair the pocket of the host tool.
[0044] FIG. 10 is a side view of another embodiment of invention
where there are two wear rings. This embodiment is very similar to
that of the single wear ring cutter bits illustrated and described
in the other figures, except that in this embodiment there is a
second wear ring 25 that fits over the snap ring shaft 28.
[0045] Installation and removal of the cutter bit is a relatively
easy process that can be performed in the field. To install the
cutter bit into a pocket, the shank of the cutter bit is inserted
into the pocket. As the cutter bit is pressed into the pocket, the
tapered edges of the split wear ring engage the outer surface of
the pocket. This causes the split wear ring to compress slightly as
the cutter bit continues into the pocket. Once the cutter bit is
fully inserted into the pocket, the flange protects the outer
surface of the pocket and the shank with the snap-ring shaft
extends beyond the other side of the pocket. A snap-ring is then
secured to the snap-ring shaft to prevent the cutter bit from
becoming dislodged from the pocket. When the cutter bit needs to be
replaced, the snap-ring is removed and the cutter bit is forced
from the pocket. This can be achieved by applying force to the end
of the shank that extends axially through the pocket until the
cutter bit is removed from the pocket.
[0046] It should be understood that while the preferred embodiments
of the invention are described in some detail herein, the present
disclosure is made by way of example only and that variations and
changes thereto are possible without departing from the subject
matter coming within the scope of the following claims, and a
reasonable equivalency thereof, which claims I regard as my
invention.
[0047] All of the material in this patent document is subject to
copyright protection under the copyright laws of the United States
and other countries. The copyright owner has no objection to the
facsimile reproduction by anyone of the patent document or the
patent disclosure, as it appears in official governmental records
but, otherwise, all other copyright rights whatsoever are
reserved.
* * * * *