U.S. patent application number 16/395365 was filed with the patent office on 2020-03-19 for rail re-profiling method and apparatus.
The applicant listed for this patent is GREENLEAF TECHNOLOGY CORPORATION. Invention is credited to Charles D. Grabowski, Donald R. Hughes.
Application Number | 20200087865 16/395365 |
Document ID | / |
Family ID | 51527634 |
Filed Date | 2020-03-19 |
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United States Patent
Application |
20200087865 |
Kind Code |
A1 |
Hughes; Donald R. ; et
al. |
March 19, 2020 |
RAIL RE-PROFILING METHOD AND APPARATUS
Abstract
A method of milling a profile of a railway rail comprises:
rotating a milling cutter including a plurality of face mounted
cutting inserts mounted about a periphery thereof, milling a
railway rail with cutting edges of the cutting inserts rotating in
a predetermined plane corresponding to at least a portion of a
desired rail profile while controlling the depth of cut of the
cutting inserts; traversing the railway rail with the milling
cutter while milling the railway rail and controlling the speed of
traverse of the milling cutter along the railway rail.
Inventors: |
Hughes; Donald R.;
(Meadville, PA) ; Grabowski; Charles D.;
(Corcoran, MN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GREENLEAF TECHNOLOGY CORPORATION |
Saegertown |
PA |
US |
|
|
Family ID: |
51527634 |
Appl. No.: |
16/395365 |
Filed: |
April 26, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14771413 |
Aug 28, 2015 |
10352001 |
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PCT/US14/26942 |
Mar 14, 2014 |
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16395365 |
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13841036 |
Mar 15, 2013 |
9617691 |
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14771413 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B23C 2210/0435 20130101;
B23C 2222/28 20130101; Y10T 407/1932 20150115; Y10T 409/3042
20150115; B23C 5/06 20130101; Y10T 409/303808 20150115; B23Q 9/0028
20130101; Y10T 409/307784 20150115; B23C 2210/0421 20130101; Y10T
409/306216 20150115; Y10T 407/1912 20150115; B23C 5/207 20130101;
Y10T 409/306384 20150115; E01B 31/13 20130101; Y10T 407/1908
20150115; B23C 2215/32 20130101; B23C 3/005 20130101; Y10T 407/1922
20150115; Y10T 409/307672 20150115; Y10T 409/30952 20150115; B23C
2210/0428 20130101; Y10T 409/308344 20150115 |
International
Class: |
E01B 31/13 20060101
E01B031/13; B23C 3/00 20060101 B23C003/00; B23C 5/06 20060101
B23C005/06; B23C 5/20 20060101 B23C005/20 |
Claims
1. A method of milling a profile of a railway rail comprising:
rotating a milling cutter including a plurality of face mounted
cutting inserts mounted about a periphery thereof; milling a
railway rail with cutting edges of the cutting inserts rotating in
a predetermined plane corresponding to at least a portion of a
desired rail profile while controlling the depth of cut of the
cutting inserts; traversing the railway rail with the milling
cutter while milling the railway rail; and controlling the speed of
traverse of the milling cutter along the railway rail.
2. The method of claim 1, comprising controlling the speed of
traverse of the milling cutter along the railway rail to speeds up
to 15 mph.
3. The method of claim 1, comprising controlling the speed of
traverse of the milling cutter along the railway rail to speeds
greater than 1 mph.
4. The method of claim 1, comprising controlling the speed of
traverse of the milling cutter along the railway rail to speeds
greater than 3 mph.
5. The method of claim 1, comprising controlling the speed of
traverse of the milling cutter along the railway rail to speeds
between less than 1 mph to 15 mph.
6. The method of claim 1, comprising controlling the depth of cut
of the cutting inserts to a depth no more than 0.040 inches.
7. The method of claim 1, comprising controlling the depth of cut
of the cutting inserts to a depth no more than about 0.010
inches.
8. The method of claim 1, comprising controlling the depth of cut
of the cutting inserts to a depth between 0.005 inches and 0.010
inches.
9. The method of claim 1, wherein milling the railway rail
comprises milling the railway rail using a conventional milling
orientation.
10. The method of claim 1, wherein milling the railway rail
comprises milling the railway rail using a climb milling
orientation.
11. The method of claim 1, further comprising: milling the railway
rail with a plurality of milling cutters, each milling cutter
including a plurality of face mounted cutting inserts mounted about
a periphery thereof, wherein cutting edges of the cutting inserts
of each milling cutter are rotated in a predetermined plane
corresponding to at least a portion of a desired rail profile.
12. The method of claim 1, further comprising controlling a width
of cut to about 0.625 inches or less.
13. The method of claim 1, wherein the milling cutter comprises one
of a bumper ring and a bumper plate.
14. The method of claim 1, wherein the cutting edge comprises an
actual cutting edge, and wherein the actual cutting edge
progressively moves along the edge as it wears.
15. The method of claim 1, wherein one or more of the cutting
inserts comprises a substantially linear cutting edge.
16. The method of claim 1, wherein the cutting inserts comprise one
of uncoated C6 grade cemented carbide and coated C6 grade cemented
carbide.
17. The method of claim 1, wherein the milling cutter is positioned
in an offset orientation comprising a distance between 35% and 40%
of its diameter.
18. The method of claim 1, wherein the milling cutter comprises a
diameter between 8 inches and 16 inches.
19. An apparatus for milling at least a portion of a desired
profile on a railway rail in situ, the apparatus comprising: a
milling cutter including a cutter body comprising a cutter face,
wherein the milling cutter is rotatable about a rotation axis; and
a plurality of cutting inserts mounted around a periphery of the
cutter face, the plurality of cutting inserts each comprising a
cutting edge extending a distance from the cutter face to engage
and mill a profile segment on the railway rail, wherein the
rotation axis is substantially perpendicular to the plane of the
profile segment to be milled on the railway rail by the cutting
inserts.
20.-41. (canceled)
Description
BACKGROUND OF THE TECHNOLOGY
Field of the Technology
[0001] The present disclosure generally relates to equipment and
techniques for milling. The present disclosure more specifically
relates to equipment and techniques adapted for milling railway
rails.
Description of the Background of the Technology
[0002] Railways networks are in use throughout the world for
freight and transit alike. Over time, railway rails become worn and
irregularities may arise, especially along the railhead profiles.
Consequently, railways must be maintained by either replacing or
re-profiling worn or deformed rails. For example, rail re-profiling
may be undertaken to address common rail deformities such as rail
corrugation, which may comprise short to long wavelengths.
Corrugations are known to cause noise, vibrations, and premature
wheel wear Rail re-profiling may also be undertaken as part of a
regular maintenance schedule aimed at extending the operational
life of rails.
[0003] To minimize interference with rail traffic and to reduce
labor costs, it is often advantageous to re-profile worn rails in
situ. While in situ re-profiling may avoid extended offline
periods, present re-profiling strategies comprising planing,
grinding, and, more recently, peripheral milling are generally slow
and/or hazardous endeavors. For example, rail grinding may employ
one or more grinding wheels mounted to a rail grinding vehicle.
Rail grinding vehicles are known to produce significant quantities
of sparks during the grinding process, which may present a
significant fire hazard along the railway at its periphery
Conventional rail re-profiling vehicles also are known to produce
chatter and may be unable to produce desirable smooth and
continuous railhead profiles. Certain conventional rail milling
vehicles employ peripheral milling techniques to mill a
predetermined profile on the rails. While presenting less fire risk
than rail grinding vehicles, rail milling vehicles typically
advance along the railway slowly and may require that the railway
be taken out of service for an extended period. Rail milling
vehicles also may be unable to continuously mill rail. For example,
peripheral milling cutters used on such vehicles are designed to
form a specific railhead profile and, therefore, are unable to
adequately adapt to changing rail conditions such as variations in
the railhead profile, curves, or transitions (such as, for
example., railway grade crossings). Consequently, the conventional
rail milling process may be slowed in order to adjust or replace
milling cutters to match the rail profile variations, adapt to
changes in the condition of the rails, or address curves or
transitions. In some instances, large sections of railway must be
ignored or are inadequately milled due to variations or
transitions.
[0004] Given the foregoing drawbacks, it would be advantageous to
develop improved techniques for rail re-profiling.
SUMMARY
[0005] According to one aspect of the present disclosure, a method
of milling a profile of a railway rail comprises: rotating a
milling cutter including a plurality of face mounted cutting
inserts mounted about a periphery thereof; milling a railway rail
with cutting edges of the cutting inserts rotating in a
predetermined plane corresponding to at least a portion of a
desired rail profile while controlling the depth of cut of the
cutting inserts; traversing the railway rail with the milling
cutter while milling the railway rail, and controlling the speed of
traverse of the milling cutter along the railway rail.
[0006] According to certain non-limiting embodiments, the method
further comprises milling the railway rail with a plurality of
milling cutters, each milling cutter including a plurality of face
mounted cutting inserts mounted about a periphery thereof. In such
method, cutting edges of the cutting inserts of each milling cutter
are rotated in a predetermined plane corresponding to at least a
portion of a desired rail profile.
[0007] According to an additional aspect of the present disclosure,
an apparatus for milling at least a portion of a desired profile on
a railway rail in situ comprises: a milling cutter including a
cuter body comprising a cutter face, wherein the milling cutter is
rotatable about a rotation axis: and a plurality of cutting inserts
mounted around a periphery of the cutter face. Each of the
plurality of cutting inserts comprises a cutting edge extending a
distance from the cutter face to engage and mill a profile segment
on the railway rail. The rotation axis is substantially
perpendicular to the plane of the profile segment to be milled on
the railway rail by the cutting inserts
[0008] According to certain non-limiting embodiments, the apparatus
further comprises a plurality of milling cutters, each milling
cutter including a cutter body rotatable about a rotation axis and
a cutter face. A plurality of cutting inserts are mounted around a
periphery of the cutter face of each of the plurality of milling
cutters, and each of the plurality of cutting inserts comprises a
cutting edge extending a distance from the cutter face to engage a
railway rail and mill a segment of a desired profile on the railway
rail
[0009] According to certain non-limiting embodiments, the apparatus
may comprise a rail vehicle on which are mounted the plurality of
milling cutters. In certain embodiments, the plurality of milling
cutters are individually mounted to respective spindles, and each
of the plurality of milling cutters is individually positionable
about a railway rail to mill a plurality of segments of a desired
profile on the railway rail.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The various embodiments of methods and apparatuses described
herein may be better understood by considering the following
description in conjunction with the accompanying drawings.
[0011] FIG. 1A is a perspective view of a milling cutter according
to various embodiments disclosed herein;
[0012] FIG. 1B schematically illustrates a milling cutter
positioned to engage and mill a railway rail according to various
embodiments described herein;
[0013] FIG. 2 schematically illustrates certain features of a
milling cutter according to various embodiments described
herein;
[0014] FIG 3 is a table providing various parameters used to
evaluate certain milling cutter configurations as described
herein;
[0015] FIG. 4 presents photographs of a milling insert used in
certain testing conducted according to parameters listed in the
table of FIG. 3;
[0016] FIGS. 5A-5C schematically illustrate features of a milling
cutter according to various embodiments described herein;
[0017] FIGS. 6A-6C illustrate certain components of a milling
cutter according to various embodiments described herein;
[0018] FIG 7 is a semi-schematic view illustrating features of a
milling insert according to various embodiments described
herein;
[0019] FIG. 8 illustrates the application of a conventional milling
orientation and a climb milling orientation to the milling of
railway rails according to various embodiments described
herein,
[0020] FIG. 9 is a photographic depiction of a milling cutter
milling a railway rail according to various embodiments described
herein;
[0021] FIG. 10 is a photographic depiction of a milling cutter
milling a railway rail according to various embodiments described
herein;
[0022] FIG. 11 is a table providing various parameters used in
evaluating certain milling cutters configurations as described
herein;
[0023] FIG. 12A schematically illustrates a milling cutter
contacting a railway rail in an angled orientation according to
various embodiments described herein;
[0024] FIG. 12B illustrates various angled orientations of a
milling cutter relative to a railway rail according to various
embodiments described herein,
[0025] FIG. 13A is a table providing various parameters used in
evaluating certain configurations of milling cutters as described
herein;
[0026] FIG. 13B is a photographic depiction of cutting inserts used
in testing described herein;
[0027] FIG. 14A is a table providing various parameters used in
evaluating certain milling cutter configurations as described
herein;
[0028] FIG. 14B is a photographic depiction of a rail re-profiled
in testing described herein;
[0029] FIG. 15 is a table providing various parameters used in
evaluating certain configurations of milling cutters as described
herein;
[0030] FIG. 16 provides photograph depictions of various cutting
inserts used in testing described herein;
[0031] FIGS. 17A-17C schematically illustrate certain features of a
milling cutter according to various embodiments described
herein;
[0032] FIG. 18A is a table providing various parameters used in
evaluating certain configurations of milling cutters as described
herein;
[0033] FIG. 18B is a photograph c depiction of a test carriage
including two milling cutters that was used in testing described
herein;
[0034] FIGS. 19A-C provide photographic depictions of various
cutting inserts used in testing described herein:
[0035] FIGS. 20A and 20B schematically illustrate certain features
of a milling cutter according to various embodiments described
herein;
[0036] FIG. 21 schematically illustrates an arrangement of a
plurality of milling cutters orientated about a railway rail to
each define a separate portion or region of the rail profile
according to various embodiments described herein;
[0037] FIG. 22 schematically illustrates aspects of a non-limiting
embodiment of a method of milling segments of a desired profile on
a railway rail as the milling cutter traverses the railway rail;
and
[0038] FIG. 23 is a photographic depiction of a railway rail
including a milled segment (facet) formed by a non-limiting method
according to the present disclosure.
DETAILED DESCRIPTION OF CERTAIN NON-LIMITING EMBODIMENTS
[0039] The present disclosure describes various embodiments of
apparatuses, milling cutters, milling inserts, and milling methods
for re-profiling railway rails. In one embodiment: a milling cutter
according to the present disclosure comprises a plurality of
cutting inserts. The cutting inserts may be positioned in one or
more orientations proximate to a railway rail to be re-profiled. In
certain forms, the milling cutter comprises a cutter body
configured to retain a plurality of cutting inserts, for example,
indexable cutting inserts, thereon. The milling cutter may traverse
the railway rail while rotating about a central axis. Each of the
plurality of cutting inserts may comprise a cutting edge configured
to engage the rail during rotation of the cutter body to thereby
remove material from the rail and provide a desired rail profile or
rail profile portion or region In various embodiments, a vehicle is
provided including one or more milling cutters configured to mill a
desired profile in a railway rail, true the rail, and provide a
continuous finish while traversing the rail at speeds greater that
1 mph, such as greater than 3 mph, up to 15 mph, 1 to 15 mph. 5 to
15 mph, 10 to 15 mph, or faster speeds. In certain embodiments, the
milling cutter may be mounted on a vehicle and is movable about one
or more axes such that the milling cutter may be adjustably
positioned proximate to the rail in one or more orientations to
restore the rail to a desired profile.
[0040] In one embodiment, one or more milling cutters provided on a
railway vehicle may be rotatable about a vertical axis or about an
axis at an angle to the vertical. For example, a milling cutter
composing a plurality of cutting inserts secured about a periphery
of a face of the milling cutter may be positioned proximate to a
rail to engage and thereby mill and impart a desired profile or
profile portion or region to the rail. According to one embodiment,
such a milling strategy may be considered a form of face milling,
which the present inventors have discovered allows for high feed
rates by suitably distributing chip load. The use of face milling
distinctly differs from milling strategies known for rail
re-profiling, such as peripheral milling. Peripheral milling may
include a cutter mounted and rotated on a horizontal axis, and
cutting inserts are spaced about the periphery of the milling
cutter in an arrangement defining the profile to be cut. Railway
vehicles conducting peripheral milling are not capable of moving at
the speeds possible with rail re-profiling methods and apparatuses
described herein. The ability to mill profiles into railway rail in
situ at higher speeds than conventional peripheral milling
re-profiling techniques may reduce the time during which the
railway is out of service for re-profiling. In addition to lacking
an ability to traverse the rail at high speeds, peripheral milling
also lacks an ability to adapt to curved rail sections. Peripheral
milling vehicles, which include single cutters defining the form to
be cut, may produce deviations from a desired rail profile along
curved rails, as well as produce an undesirable scalloped finish on
the railhead.
[0041] In certain embodiments according to the present disclosure,
multiple face milling cutters may be mounted on a rail vehicle and
are individually positionable to contact the rail in different
orientations to re-profile the rail. The multiple milling cutters
may be orientated such that at least two of the milling cutters are
positioned to mill different portions or regions of the desired
rail profile on the rail. For example, in one embodiment, a first
milling cutter may be positioned to mill a first facet on the rail,
and a second milling cutter may be positioned to mill a second
facet on the rail. Both the first and second facets may be
simultaneously milled on different regions of the rail as a vehicle
on which the milling cutters are mounted traverses the rail.
[0042] In one embodiment according to the present disclosure, the
milling cutters may be mounted on one or more dedicated rail
vehicles. The milling cutters may each be operably coupled to a
dedicated or shared motor operable to rotate the milling cutters at
a desired rate. In one embodiment, two or more milling cutters may
couple to a positioning member or system configured to position the
milling cutter proximate to a rail. The positioning member or
system may comprise motors, gears, hydraulics, pumps, or the like.
In various forms, the positioning member or system may be manually
operated, computer assisted, or automated. For example in one
embodiment, a positioning member or system is operably coupled to a
control system configured to control various operations of the
milling cutter. In one embodiment, the control system comprises a
guidance system. The guidance system may be programmed to scan
ahead of the milling cutter, e.g., employing a laser or other
detection apparatus, to provide information to the guidance system
regarding the characteristics of approaching segments of the rail.
The guidance system may use the information to calculate an optimum
depth of cut, width of cut, or modification to a milling cutter
position or orientation, or supply of power. In various
embodiments, the guidance system may control or provide feedback to
other system components to modulate a cutting operation, either
directly or indirectly. For example, feedback from the guidance
system may result in a modification to the position of the spindle
head
[0043] Referring to FIGS. 1A, 1B, and 2, in various embodiments
according to the present disclosure, a method and apparatus for
profiling a railway rail comprises rotating a milling cutter 10
about an axis "A" and in a controlled orientation and position
while contacting a railway rail 11. The milling cutter 10 may
include a cutter body 12 that defines a central diameter 14 and an
outer circumference 16. The cutter body 12 may include a cutter
face 18 defining a plurality of cutting insert positions 20
disposed about a periphery 22 of the cutter face 18. Each of the
plurality of cutting insert positions 20 may be configured to
receive a cutting member, e.g., a cutting insert 24 The cutting
inserts 24 may be positioned within the insert positions 20 and
retained therein with a retaining assembly 26. e.g., a wedge, bolt,
or other clamping assembly known In the art. The milling cutter 10
illustrated in FIG. 1A comprises a plurality of cutting inserts 24,
each positioned within a nest 28. The cutting inserts 24 may be
positioned to extend a distance from the cutter face 18 to engage a
workpiece, e.g., a rail 11, at one or more cutting edges 30 of the
individual cutting insert 24 In various embodiments, the central
diameter 14 of the cutter body 12 may be dimensioned to mount to a
spindle 32 for rotation about rotation axis "A". The cutter body 12
further defines a plurality of holes 34 structured to receive bolts
to fix the rotation of the spindle 32 to the cutter body 12.
[0044] In operation, the milling cutter 10 may be rotated by the
spindle 32 while continuously traversing the rail 11 so that the
rail 11 is continuously fed to the rotating cutting inserts 24
positioned about the periphery of the cutter face 18, as generally
depicted in FIG. 1B. To produce a desired profile or facet (i.e., a
profile portion or region) on a region of the rail 11, the milling
cutter 10 and the cutting inserts 24 secured thereto may be
orientated at a predetermined angle with respect to the axis "X-X"
of the rail 11. For example, in one embodiment, the milling cutter
10 is positioned relative to the rail 11 so that the cutting edges
30 of the cutting inserts 24 are positioned in a predetermined
plane corresponding to at least a portion or region of the profile
to be milled on the rail 11.
[0045] In various embodiments, a rail re-profiling apparatus and
method comprises a rotating milling cutter 10 having a plurality of
cutting inserts 24 mounted around the periphery 22 of the cutter
face 18. According to certain embodiments, the milling cutter 10
may traverse a workpiece, e.g.; a railway rail, at a speed of less
than 1 mph up to about 15 mph, at 5 to 15 mph, at 10 to 15 mph, or
at faster speeds. For example, the milling cutter 10 may be rotated
and pass along the rail 11 such that the rail 11 is fed to the
rotating milling cutter 10 at a feed rate corresponding to the
speed of the vehicle on which the milling cutter 10 is mounted, to
produce a desired rail profile.
[0046] To develop the disclosed milling apparatuses and methods for
re-profiling surfaces on a railway rail while maintaining adequate
rail finish and profile, various high feed milling cutter 10 and
cutting insert 24 combinations where prepared and tested In
general, a high feed milling cutter 10 was developed that utilizes
insert lead angles to create a chip-thinning effect that allows the
milling cutter 10 to run at higher than normal feed rates at
relatively shallow depths of cut. According to various embodiments,
the high feed milling cutter 10 preferably comprises a medium pitch
or a fine pitch milling cutter FIG. 1A is a perspective view of a
generalized depiction of a milling cutter 10 configurable as a high
feed milling cutter according to various non-limiting embodiments.
For example, the milling cutter 10 may be mounted to a rail car for
high speed milling of rails 11. In this configuration, the milling
cutter body 12 has an 8-inch diameter and includes 16 cutting
insert positions 20 housing 16 separate cutting inserts. FIG. 2
illustrates a nested cutting insert configuration and includes a
cutting insert 24 in a nest 28 adapted to receive the insert. The
illustration at the top right of FIG. 2 provides a top view of the
cutting insert 24 and a nest 28 within which the cutting insert 28
is nested. The illustration at the top left of FIG. 2 provides a
side view of the nest 28 and cutting insert 24. The illustration at
the bottom right of FIG. 2 provides an end view, e.g., a view of
the portion of the nest and cutting insert 24 positioned about the
circumference of the cutter body 12 when held within the cutter
body. The insert 24 is disposed at a 2.degree. lead angle (measured
between 44a and 44b)in the nest, and the insert 24 has an
11.degree.0 degree relief (measured between 29a-29b).
[0047] The effectiveness of the milling cutter 10 for high speed
milling of railway rails has been demonstrated by rotating the
milling cutter 10 against a rotating rail steel wheel to simulate
traversing a railway rail. Specifically, the milling cutter 10 was
mounted to a spindle 32 extending from a 30 horsepower test
machine. The milling cutter 10 was rotated counter-clockwise
against a 37-inch diameter wheel formed of rail steel that was
rotated clockwise at various rotational speeds to correspond to a
specific mph. The parameters of this test are provided in FIG. 3.
During the test, the width of cut was maintained between about
0.38-0.62 inches at a depth of cut of about 0.010 inches. In Tests
1-3, the rotational speed of the milling cutter was progressively
ramped from an initial 700 RPM up to 1500 RPM, and the rotational
speed of the rail steel wheel was progressively ramped from a
rotational speed corresponding to 0.5 mph up to a speed
corresponding to 1 mph. A full complement of 16 inserts were
mounted on the milling cutter and used in Tests 2-6 listed in FIG.
3. Following the speed ramping tests, new inserts 24 were
positioned in the cutter body 12 for Test 4 and Test 5 listed in
FIG. 3 in order to evaluate two sets of PVD-coated carbide inserts
2.4. The cutting insert grades used in the testing were
Greenleaf.RTM. grade G-935, a PVD-coated C5 cemented carbide grade,
and Greenleaf.RTM. grade G-915, a PVD-coated C1 cemented carbide
grade, both of which grades are available from Greenleaf
Corporation, Saegertown, Pa. USA.
[0048] FIG. 4 (left panel) is a photographic depiction of a top
view of a cutting edge 30 of a cutting insert 24 show ng typical
edge wear observed in Test 5. FIG. 4 (right panel) is a
photographic depiction of a side view of the cutting edge 30
depicted in the left panel. Wear land (36a-36b) measurements were
taken from each insert 24 to determine which test grade performed
more favorably. The average wear land (36a-36b) for cutting inserts
made from Greenleaf.RTM. grade G-935 material used in Test 4 was
0.009 inches, with 2 of the 16 inserts showing more than 0.019
inches of wear land (36a-36b). The average wear land (36a-36b) for
the cutting inserts made from Greenleaf.RTM. grade G-915 material
used in Test 5 was 0.013 inches, with 6 of the 16 inserts showing
mere than 0.019 inches of wear land (36a-36b).
[0049] While the heavy feed rate used in the testing, ranging
between 0.037 to 0.047 inches per insert per revolution (which may
be shortened herein to "inches per insert"), produced less than
optimal part finish, the part finish was within acceptable limits.
Consequently, the results at 1 mph demonstrated that an acceptable
rail finish may be achieved at higher feeds. The results also
demonstrated that with the proper milling cutter and cutting insert
configurations, higher feed rates may be achieved with acceptable
insert wear.
[0050] To further demonstrate that railway rails may be milled at
high travel speeds while maintaining required rail finish and
profile, according to the present disclosure, various milling
cutter configurations were mounted to a test machine and used to
mill an 11 foot segment of railway rail held in a rotary fixture to
facilitate indexing for milling various facet angles on the rail.
The test machine was equipped with a 35 horsepower horizontal
machining center capable of a maximum linear feed rate of 400 inch
per minute (IPM), or about 0.33 mph. In this test, two milling
cutter and cutting insert geometries were evaluated using a 10 inch
diameter cutter body configured to hold 32 cutting inserts.
[0051] A first milling cutter and insert configuration 100
evaluated is shown in FIGS. 5A-5C. In the first configuration 100,
the milling cutter 110 comprises a neutral radial and a positive
axial rake configuration 100 Referring to the radial view FIG. 5A
and the plan views FIG. 5B and 5C of configuration 100; the milling
cutter 110 comprises a cutter body 112 defining a central diameter
114 and an outer circumference 116 extending outward a diameter
"D". The central diameter 114 is positioned about a rotation axis
"A", and the milling cutter 110 is dimensioned to mount to a
spindle 132. The milling cutter 110 includes a plurality of holes
134 configured to receive bolts to fix the cutter body 112 to the
rotation of the spindle 132. Those having ordinary skill in the art
will appreciate that cutter bodies may comprise various
arrangements of spindle fittings. For example, cutter bodies 112
may be designed with fittings including holes or slots configured
for mounting to one or more spindle or spindle adapter designs. As
such, unless stated otherwise, the present disclosure is not
limited by the particular spindle fitting arrangements in the
illustrated embodiments.
[0052] The cutter body 112 extends to a cutter face 118 defining 32
cutting insert positions 120 about a periphery 122 of the cutter
face 118 The cutting inserts, e.g., 124x, 124y, are secured within
the insert positions 120. Each of the cutting inserts extends a
distance from the cutter face 118 and defines a cutting edge 130
extending from the cutter face 118. The cutter body 112 is
configured to be rotated about axis "A" in the rotational direction
Indicated by arrow "R". The views shown in FIGS. 5A-5C illustrate
geometries of the cutting inserts 124x, 124y. Cutting insert 124y
is shown at the six o'clock position in FIGS. 5A and 5B
illustrating a wiper flat portion 40 extending 0.140 inches to an
angled portion 42 (see cutting insert detail in FIG. 7), providing
a 2.degree. angle (measured between 144a and 144b). Cutting insert
124x is shown at the 3 o'clock position in FIGS. 5A and 5C
illustrating a positive rake. It is to be appreciated that while
cutting inserts 124x. 124y are referenced by different reference
numbers, in various embodiments, inserts 124x, 124y, and the other
insert mounted on the cutter body 112 may share the same or similar
geometries and orientations.
[0053] A second milling cutter and insert configuration 200 that
was evaluated is shown in FIGS. 6A-6C. In the second configuration
200, the milling cutter 210 comprises a double negative (axial and
radial) rake configuration 200 Referring to the radial view FIG 6A
and the plan views FIGS. 6B and 6C of the milling cutter 210, the
milling cutter 200 comprises a cutter body 212 defining a central
diameter 214 and an outer circumference 216 extending to a diameter
"D" The central diameter 214 is positioned about a rotation axis
"A" and is dimensioned to mount to a spindle 232. The cutter body
212 defines a plurality of holes 234 structured to receive bolts to
fix the cutter body 212 to the rotation of the spindle 232. The
cutter body 212 extends to a cutter face 218 defining 32 insert
positions 220 about a periphery 222 of the cutter face 218. The
cutting inserts (e.g., 224x, 224y) are secured within the insert
positions 220, extend a distance from the cutter face 218; and
include cutting edges 230. The milling cutter 200 is rotated in the
rotational direction indicated by arrow "R". The radial view or
side view of the milling cutter 210 illustrates geometries of the
inserts 224x, 224y. In the views provided in FIGS. 6A and 6B,
cutting insert 224y is shown at the six o'clock position
illustrating a wiper flat portion 40 extending 0.140 inches to an
angled portion 42 (see cutting insert detail in FIG. 7), providing
a 2.degree. angle (measured between 244a and 244b). Cutting insert
224x is shown at the 3 o'clock position in FIGS 6A and 6C
illustrating a negative rake. It is to be appreciated that while
inserts 224x, 224y are referenced by different reference numbers,
in various embodiments, inserts 224x, 224y, as well as other
cutting inserts mounted on the cutter body 212, may share the same
or similar geometries and orientations
[0054] As indicated, FIG. 7 provides a semi-schematic detail view
of the cutting inserts 124y and 224y depicted in FIGS. 5A-5C and
5A-6C, respectively, and further illustrates the geometry of the
cutting inserts and certain evaluated parameters The cutting insert
124y, 224y is depicted in FIG. 7 engaging a railway rail 11, and
the insert includes a wiper flat portion 40 transitioning to an
angled portion 42. The programmed feed rate 70, actual chip load
(between 72a and 72b), and maximum depth of cut (between 46a and
46b) indicated in FIG. 7 generally correspond to the test
parameters, which are further described below.
[0055] In addition to evaluating milling cutter and cutting insert
geometries, relative orientations between a milling cutter and a
railway rail also were investigated. FIG. 8 illustrates a
side-by-side comparison depicting "conventional" (up) milling 300
and "climb" (down) milling 400. The lower portion of the figure
depicts milling cutters 310, 410, which may be applicable to any of
the milling cutters described herein Both milling cutters 310, 410
are positioned proximate to a rail 11. The cutter faces 318, 418 of
the cutter bodies 312,412 retain a plurality of cutting inserts
324, 42.4 comprising cutting edges 330, 430 positioned to mill the
rail 11 when the cutter 310, 410 rotates in the direction of arrows
"R" about rotation axis "A". The rail 11 may define an axis "X".
According to certain embodiments, the rail 11 may be fed to the
cutting inserts 324, 424 with the milling cutter 310. 410
traversing the rail, as indicated by arrow 52 In the upper portion
of FIG. 8, the milling cutters 310. 410 are illustrated in an axial
perspective from the spindle at the back of the milling cutter body
312, 412. In a "conventional" milling orientation 300, the chip
thickness starts at or near zero and increases to a maximum to form
the width of cut (measured between 48a and 48b). In a "climb"
milling orientation 400, each cutting edge engages the material at
a definite point and the width of cut (between 48a and 48b) starts
at a maximum and decreases throughout the cut. In both orientations
depicted in FIG 8, the axis "A" of the milling cutter 310; 410 is
offset from axis "X", as generally illustrated in FIG. 8 In various
embodiments, however, the axis "A" of the milling cutter 310, 410
may be at least partially centered on axis "X" when the milling
cutter 310, 410 is milling the rail 11.
[0056] FIG 9 provides a photographic depiction of a milling cutter
510 coupled to a spindle 532 and performing work on a rail 11 In an
offset orientation 500. In particular, milling cutter 510 comprises
a cutter body 512 configured to house a plurality of cutting
inserts 524 positioned about a periphery 522 of a cutter face 518
of the milling cutter 510. As introduced above, the milling cutter
510 may be positioned in either a conventional milling orientation
or a climb milling orientation. As shown in FIGS. 8-9, the rotation
axis "A" may be partially offset from axis "X", e.g., and the
rotation axis "A" may be centered along the facet or width of cut
as shown in FIG. 10. FIG. 10 illustrates a milling cutter 610
coupled to a spindle 632 and performing work on a rail 11 in a
centered orientation 600. The milling cutter 610 comprises a cutter
body 612 configured to house a plurality of cutting inserts 624
positioned about a periphery 622 of a cutter face 618 of the
milling cutter 610.
[0057] As described above, to further demonstrate that rails 11 may
be milled at high speeds while maintaining adequate rail finish and
profile according to the present disclosure, milling cutters 110.
210, 310, 410, 510, 610 comprising the above cutter body/cutting
insert configurations 100, 200 and orientations 300. 400, 500, 600
were mounted to a test machine providing a maximum linear feed rate
of 400 IPM (inches per minute) to mill an eleven-foot long railway
rail 11 held in a rotary fixture 60 (as shown in FIG. 10). The
rotary fixture facilitates indexing the rail 11 for milling various
facet angles on the rail 11. During the testing, the negative rake
configuration 200 was observed to provide a better part finish at
higher feed rates than the positive rake configuration 100. For
example, compared to the positive rake configuration 100, the
finish produced by the negative rake configuration 200 appeared
less wavy at the higher feed rates. Notably, the negative rake
configuration 200 cutting inserts 24 also offer additional cutting
edges. Climb milling 400 with the milling cutter 410, 510 in an
offset position 500 approximately 4 inches off center axis "A" was
also found to provide a quieter cut with a better surface finish.
FIG. 11 provides parameters of the testing, in which 32 test runs
(G001-G0032) were conducted to evaluate the double positive milling
cutter configuration 100 oriented on-center 600.
[0058] Referring to FIG. 12A, to address the various rail facets
that may be milled in a rail to together provide a desired railhead
profile, testing was conducted in which the milling cutter was
positioned at various cutter tip angles 56a-56b off the horizontal
VET through approximately 45.degree.. FIG. 12B illustrates nine
examples of cutter tip angles off the horizontal "B" on both sides
of the rail for profile or facet regions 82a, 82b on a rail 11. The
nine set of facets (18 total facets) were milled on the rail 11
using configuration 100 or 200 to provide a desired rail profile or
contour. During testing, the width of cut (measured between 48a and
48b) was approximately 0.12-1.12 inches, and the depth of cut was
maintained between 0.005 and 0.010 inches (see, e.g., FIG. 7). Only
four inserts where mounted on the cutter body to perform the test
Consequently, the work performed by each cutting insert was
estimated to equate to about 3.03 mph at a full load of 32 inserts.
Various features of the milling cutter 710 illustrated in FIG. 12A
may be similar to the features of the milling cutter 410
illustrated in FIG. 8. For example, milling cutter 710 was
positioned in an offset orientation 700. Accordingly, like features
are identified by numbers corresponding to features of milling
cutter 410 and, for purposes of brevity, are not further
described.
[0059] As stated above, the maximum linear IPM feed for the test
machine used in the test was 400 IPM Accordingly, to further push
linear feed evaluation, in mph, various test passes where run using
only 1 or 2 cutting inserts The parameters for these tests are
provided in FIG. 13A. Both positive (Tests 1-7) and negative (Tests
8-10) milling cutter configurations 100, 200 were tested. A climb
milling orientation 400 combined with an offset cutter-rail
orientation 700 of 4 inches was used in ail the tests. Width of cut
was approximately 0.12-1.12, and the insert grade was
Greenleaf.RTM. grade GA-5125 material, a CVD-coated C6 grade,
available from Greenleaf Corporation. Saegertown, Pa. USA. The IPM
feed was varied between 242.0 IPM and 400.4 IPM. The estimated mph
feed with a full insert load of 32 inserts is between 4.83 mph and
12.00 mph. For example, for Tests 6 and 10, the programmed feed was
run at 0.360 feed per insert (see, e.g., FIG. 7) at 1,100 RPM,
reaching 396.0 IPM of linear feed with one insert. With a full load
of 32 cutting inserts run at an equivalent inch per insert feed
rate, the estimated mph feed is about 12 mph. FIG. 13B is a
photographic depiction of cutting inserts used in tests G008, G001,
and G002. The insert tops or rake faces showed no damage and only
flank wear was visible. The wear land (between 36a and 36b) for the
G002 insert was measured to about 0.025 inches. Notably, increased
wear was observed at the 2.degree. wiper flat transition (generally
at line T-T). It is believed that addition of a radius to the
cutting insert may reduce the observed increase in wear in this
region
[0060] One non-limiting embodiment of a technique for milling a
desired profile, portion of a profile, or "facet" on a surface of a
railway rail while traversing the rail may be better understood by
referring to FIG. 22, which schematically depicts a milling cutter
1200 including a cutter body 1202 rotatable about a rotation axis
"X". FIG. 22 depicts the periphery of the cutter body 1202 in
phantom, looking downward onto the rail surface being machined, and
indicates the positions of several of the many milling inserts 1204
secured to the cutter body 1202 about a periphery of a cutter face
of the cutter body 1202. Cutter body 1202 is shown face milling a
region of a top surface 1207 of a railway rail 1208 to produce a
desired rail profile portion or facet 1210 extending longitudinally
along the top surface 1207 of the railway rail 1208. The facet 1210
may be one of several facets milled onto the top surface 1207 of
the railway rail 1208 to provide a desired rail profile and thereby
re-profile the top surface 1207. The cutter body 1202 rotates about
a rotation axis "X" in the rotational direction shown in FIG. 22
(clockwise as seen from the perspective of FIG. 22) as the cutter
body 1202 also traverses longitudinally along the railway rail
1208. Thus, the motion of the milling inserts 1204 relative to the
top surface 1207 of the railway rail 1208 is a result of both the
rotational motion of the cutter body 1202 about rotational axis X
and the motion of the cutter body 1202 in the illustrated
longitudinal direction along the railway rail 1208.
[0061] As will be understood from FIG 22, the milling cutter 1200
may be positioned so that a milling insert 1204 enters a cut being
machined on the top surface 1207 of the railway rail 1208 at a
desired approach angle. One such approach angle is an angle .pi.,
which is defined as the angle between a cutting edge of the milling
insert and the longitudinal axis of the railway rail top surface.
In certain embodiments, the angle .pi., preferably is in a range of
from 20.degree. to 50.degree.. Each milling insert 1204 preferably
sweeps down the railway rail 1208 as the milling cutter 1202
rotates and longitudinally traverses the rail 1208 in a manner that
utilizes the entire or nearly the entire cutting edge of the
milling insert 1204 to mill material from the rail 1208, thereby
distributing heat and wear over the entire or nearly the entire
cutting edge of the milling insert 1204. The movement of milling
inserts 1204 relative to the top surface 1207 of the rail 1208
creates a shearing action down the rail 1208, continuously removing
material to form the desired facet 1210 along the top surface
1207
[0062] Again referring to FIG 22, in certain non-limiting
embodiments of the method described in connection with that figure,
in addition to providing an angle .pi. in the range of 20.degree.
to 50.degree.. The rotational speed of the cutter body 1202 is
adjusted so as to avoid forming a facet composed of a pattern of
mill markings or "cross hatches" extending across the facet at an
angle that is generally 90.degree. relative to the longitudinal
axis of the railway rail 1208. Milling a facet along a railway rail
in a way that produces such a mill marking pattern may increase
machining pressure and adversely affect cutting insert life and
rail surface finish. One example of a desirable mill marking
pattern for a facet milled on a top surface of a railway rail
according to the present disclosure is shown in FIG. 23, wherein
the mill markings in the facet formed by the milling method extend
across the facet at an angle of approximately 45.degree. relative
to the longitudinal axis of the railway rail. As depicted In FIG
23. The left side of the railway rail is the inside edge, also
known as the "gage side", which guides the wheels of the locomotive
and rail cars. The outside of the rail, also known as the "field
side", may not require re-profiling as it does not normally guide
the wheels.
[0063] FIG. 14A provides test parameters used to evaluate two
coated cemented carbide cutting insert grades, Greenleaf.RTM. grade
GA-5125 (Test 1) and Greenleaf.RTM. grade G-955 (Test 2), both of
which are available from Greenleaf Corporation. Saegertown, Pa.
USA. For Tests 1 and 2, the milling cutter 210 included only a
single cutting insert 24 in a negative rake configuration 200. A
climb milling orientation 400 was used in both tests, and the
milling cutter was oriented at a cutter-rail offset 700 of 4
inches. The programmed feed per insert at 825 RPM was 0.360,
reaching 297 IPM linear feed with the single insert. The equivalent
mph feed with a full insert load of 32 cutting inserts is estimated
to be about 9.00 mph. Width of cut was approximately 0.12-0.5
inches. FIG. 14B is a photographic depiction of a rail 511
re-profiled in the test, evidencing acceptable part finish.
[0064] To further evaluate insert grades at an increased width of
cut, additional tests were performed using cuter configuration 200
and three coated cemented carbide insert grades Greenleaf.RTM.
grade GA-5125, Greenleaf grade G-935, and Greenleaf.RTM. grade
G-955. all of which are available from Greenleaf Corporation,
Saegertown, Pa. USA. The parameters for this test are provided in
FIG. 15. Cutting inserts composed of each grade were run in the
same milling cutter for the same time for comparison purposes. The
depth of cut was 0.060 inches and the width of cut was maintained
at approximately 2.50 inches. FIG. 16 is a photographic depiction
of the cutting inserts of each grade showing the most wear from
each of the four tests. The cutting inserts from Test 1 exhibited
the most wear and indicated that for certain cutting inserts, as
the width of cut increases, a corresponding decrease in insert life
may be observed. Thus, in various embodiments: a plurality of
milling cutters may be positioned such that one or more of the
milling cutters re-profiles a railway rail along a small facet or
width of cut. Accordingly, as described in more detail below, a
milling cutter apparatus according to the present disclosure may
comprise a rail vehicle having mounted thereto a plurality of
milling cutters configured to mill a plurality of facets to
together define a desired rail profile. Comparing the cutting
inserts from Test 1 with the cutting inserts from Tests 2-3 also
shows that, as cutting speeds increase, a corresponding decrease in
cutting insert life may be observed. Thus, in various embodiments,
the plurality of milling cutters may be positioned such that one or
more of the milling cutters are positioned to re-profile a rail
with a narrow facet and at a reduced RPM.
[0065] Referring to FIGS. 17A-17C, which provide an axial view FIG.
17A and a radial view FIG. 17B (a portion of which is magnified in
the view provided in FIG. 17C of a milling cutter 810. The milling
cutter 810 comprises a cutter body 812 defining a central diameter
814 and an outer circumference 816 defined by diameter "D". The
central diameter 814 is positioned about a rotation axis "A" and is
dimensioned to mount to a spindle 832. The cutter body 812 defines
a plurality of holes 834 configured to receive bolts to fix the
cutter body 812 to the rotation of the spindle 832. The cutter body
812 extends to a cutter face 818 defining 32 insert positions 820
about a periphery 822 of the cutter face 818. The cutting inserts,
e.g.. 824x, 824y, are secured within the insert positions 820. The
cutting inserts 824x, 824y extend a distance from the cutter face
818 to define cutting edges 830 extending therefrom, and the
milling cutter 810 is configured to be rotated in the rotational
direction indicated by arrow "R". The radial view or side view of
the milling cutter 810 illustrates geometries of the inserts 824x,
824y. In the views provided in FIGS. 17A-17C, cutting insert 824y
is shown at the six o'clock position illustrating a substantially
linear portion 878 of the insert 824y presented at the cutter face
818. Angle 844a-844b comprises about a 0.degree. angle. Depth of
cut is illustrated between 846a-846b. Cutting insert 824x is shown
at the 3 o'clock position in FIGS. 17A and 17B illustrating a
negative rake. It is to be appreciated that while inserts 824x,
824y are referenced by different reference numbers, in various
embodiments, cutting inserts 824x, 824y. as well as other cutting
inserts mounted on cutter body 812, may share the same or similar
geometries and orientations.
[0066] The milling cutter illustrated in FIGS. 17A-17C also
comprises a bumper plate 880 positioned at the cutter face. In
various embodiments, a bumper plate 880 may be positioned adjacent
to one or more cutting inserts, e.g., 824x, 824y, between an inner
circumference of the milling body and the periphery 822 of the
cutter face 818, to protect the cutter body and the inserts from
wear and breakage due to excessive depth of cut. The bumper plate
880 may also provide a hard stop to limit the depth of cut from
exceeding a maximum value. For example, in one embodiment, a
differential in axial extension of the bumper plate 880 and the
cutting insert 824ax, 824y may be defined between 882a-882b. This
distance may be greater than the desired depth of cut 846a-846b. It
is to be appreciated that any of the milling cutters disclosed
herein may comprise a bumper plate. Additionally, it is
contemplated that a bumper plate may comprise a modular component
that may be added when needed and then removed after use. In
certain embodiments, multiple bumper plates may be provided for a
particular milling cutter Bumper plates may comprise various
thicknesses or may be configured to be adjustable via shims, for
example. Bumper plates may also comprise rings or discs extending
about a circumference of the cutter face 818. Bumper plates may
comprise other shapes and configurations such as segmented plates
or segmented rings, for example. In various embodiments, the bumper
plate comprises a ring including a rigid material to protect the
cutter body. In certain embodiments, the bumper plate comprises a
rigid metallic material or a rigid polymer or ceramic.
[0067] Cutting insert wear is an important aspect that must be
considered in a railway rail re-profiling method When cutting
inserts wear beyond a certain level, they must be indexed or
replaced In some instances, indexing or replacement may be a
time-consuming process, and may further increase the time that a
railway segment is out of service. To further evaluate insert wear,
additional tests were performed using the milling cutter
configuration illustrated in FIGS. 17A-17C. In addition to
providing the configuration described above with respect to FIGS.
17A-17C, the inserts 824x, 824y received an edge preparation
comprising a 0.015-0.020 inch land and a 0.002-0.003 inch hone. The
test included mounting the milling cutter to a test carriage to
re-profile a length of railway rail in situ. FIG. 18A provides the
parameters used for the testing. FIG. 18B is a photographic
depiction of a portion of the test carriage 884. The test carriage
884 composed two milling cutters 810a, 810b mounted to spindle
832a, 832b, respectively The cutter faces 818a, 818b are visible.
The milling cutters 810a, 810b were separately angled and disposed
in an offset orientation with respect to the rail 11 to mill
segments of a profile on the rail.
[0068] FIGS. 19A-19C are a photographic depictions of the cutting
inserts used in Tests 4-8 referenced in FIG 18A. The right panel,
includes cutting edges (shown toward the top of the page) for 16
cutting inserts, representing 8 cutting inserts for each milling
cutter (although the milling cutter was equipped to hold 32 cutting
inserts). As can be seen from FIGS. 19A-19C, the same cutting
insert cutting edges could be run much farther until indexing was
necessary. The finish of the rails following re-profiling using the
apparatus and method as described herein was determined to be
acceptable. The top left panel depicts a magnified view of cutting
insert 924. The indicated portion of the cutting edge 930 is
further magnified in the lower left panel, which shows the top 925
of the cutting insert 924. The edge prep is indicated between
927a-927b. The wear land (between 936a-936b) was approximately
0.010-0.015 inches. As understood to those having ordinary skill, a
wear land is a flattened worn area on a cutting insert cutting edge
that forms due to abrasive wear from contacting a workpiece (such
as, e.g., a railway rail). It is believed that as wear lands
increase, the milled surface finish of the rail may deteriorate,
and cutting pressures and power consumption may also increase. Due
to the unique nature of the disclosed apparatuses and methods, wear
lands may be able to increase to 0.04 inches and beyond before
adverse affects require a cutting insert to be indexed or
replaced.
[0069] Referring to FIGS. 20A and 20B, according to various
embodiments, a milling cutter 910 comprises a bumper ring 990
positioned about the cutter face 918. The milling cutter 910 may
comprise features similar to any of the milling cutters disclosed
herein. Accordingly, similar features are identified by similar
reference numbers and, for the sake of brevity, will not be
repeated. The bumper ring 990 comprises a ring extending about a
circumference of the milling cutter 910, outward of the periphery
of the cutter face 922 housing the cutting inserts. For example, a
radial distance between a cutting insert 924 and the rotation axis
W is shorter than a radial distance between the bumper ring 990 and
the rotation axis "A". In addition to a bumper ring 990, the
milling cutter 910 also comprises a bumper plate 980 positioned at
the cutter face. In various embodiments, a bumper plate 980 may be
positioned adjacent to one or more cutting inserts, e.g., cutting
inserts 924x, 924y. between an inner circumference of the milling
body and the periphery 922 of the cutter face 918, to protect the
cutter body 912. The bumper ring 990 may provide a hard stop to
limit the depth of cut from exceeding a maximum value, such as when
traversing transitions, gaps between rails, or mushroomed joints.
In one embodiment, a differential in axial extension of the bumper
ring 990 and the cutting insert 924ax, 924y may be defined between
992a and 992b. This distance may be greater than the desired depth
of cut and, when the milling cutter 910 is also equipped with a
bumper 980, the axial extension of the insert 924x. 924y may be
greater than both the bumper plate 980 and the bumper ring 990. It
is to be appreciated that any of the milling cutters disclosed
herein may comprise a bumper plate 980 and/or a bumper ring 990, in
some embodiments, the bumper plate 980 and/or the bumper ring 990
may be modular. For example, the bumper ring 990 may be removable
or customizable. In one embodiment, shims may be placed between the
bumper ring 990 and the cutter body 912 at position 994 to increase
the axial extension of the bumper ring 990. It is contemplated that
the bumper ring 990 may comprise a modular component. The modular
component may be added when needed or removed when not needed. In
certain embodiments, multiple bumper rings 990 may be provided to
suit a desired milling cutter. Bumper rings 990 may comprise
various thicknesses or may be configured to be adjustable via
shims, for example. Bumper rings 990 may also comprise rings,
plates, or discs extending about a circumference of the cutter face
918. Bumper rings may also comprise segmented rings, plates, or
discs. In various embodiments, the bumper ring comprises a ring
comprising a rigid material to protect the cutter body. In one
embodiment, the bumper plate comprises a rigid metallic material or
a rigid polymer or ceramic.
[0070] FIG. 21 illustrates a first milling cutter 1010 and a second
milling cutter 1110, each comprising a cutter body 1012, 1112
having a plurality of cutting inserts 1024, 1124 disposed along the
periphery of a cutter face 1018, 1118. The cutting inserts define
cutting edges 1030. 1130 configured to engage the rail 11 to form a
rail profile Both milling cutters 1010, 1110 are positioned in an
offset orientation such that the rotation axis "A" is offset from
the axis "X" of the rail and the work. In operation, the first and
second milling cutters 1010. 1110 rotate about their respective
rotation axes "A" and may traverse the rail 11 at speeds of 1 mph
or more. The rotation of the milling cutters 1010, 1110 may pass
the cutting edges 1030, 1130 of the cutting inserts 1024, 1124 over
the rail 11 such that each sequentially engages the rail to remove
a portion of rail material. As shown, multiple milling cutters
1010, 1110 may be positioned about the rail 11. One or more of the
milling cutters 1010. 1110 may be positioned in different angular
orientations with respect to the rail 11. Thus, in certain
embodiments, a plurality of milling cutters may be positioned in
differing orientations about the rail 11 to mill a plurality of
facets (i.e., profile regions or segments) along the rail and
thereby provide the desired rail profile. In FIG. 21, the first
milling cutter 1010 forms a facet along the rail at a position
generally indicated by arrow 50, while the second milling cutter
1110 forms a facet along the rail 11 at a position generally
indicated by arrow 51. In various embodiments, multiple milling
cutters 1010, 1110 may be positioned proximate to multiple tracks
and may be mounted on the same or multiple rail vehicles. For
example, in one embodiment, one or more large diameter milling
cutters are mounted to a first rail vehicle and one or more smaller
diameter milling cutters are mounted to the first rail vehicle in a
different position or are mounted to a second rail vehicle. The
large diameter milling cutters may perform the majority of the work
on open rail, while the small diameter milling cutters may be
engaged for tighter working conditions, such as near transitions or
at grade crossings.
[0071] In various embodiments, a method of profiling a rail
comprises positioning a pair of milling cutters 1024, 1124
proximate to the rail 11, traversing the rail 11, engaging the rail
11 with cutting edges 1030, 1130, and milling the rail 11. For
example, a first milling cutter 1024 may be positioned at a first
angle and a second milling cutter 1124 may be positioned at a
second angle relative to the rail. In one embodiment, the first
milling cutter 1024 is positioned proximate to one side of the rail
at a first angle to the rail, the second milling cutter 1124 is
positioned proximate to the other side of the rail at a second
angle to the rail, and the first and second angles are
substantially the same (e.g.. a-a. b-b in FIG. 12B). Accordingly,
the pair of milling cutters 1024. 1124 may be positioned to mill a
set of matched facets along both sides of the rail. In one such
embodiment, multiple pairs of milling cutters may be positioned
along the rail 11 such that each pair mills a set of matched facets
while traversing the rail 11. In one embodiment, the pairs of
milling cutters are positioned to progressively or sequentially
mill the rail from a lower portion of the profile to a higher
portion of the profile. For example, with reference to FIG. 12B, a
first pair of milling cutters may be positioned to mill matched
facets a-a, b-b, and a second pair of milling cutters may be
positioned to mill matched facets c-c, d-d. In one embodiment, as
the rail vehicle moves along the rail 11, a first pair of milling
cutters engages the rail and mills a first matched set of facets, a
second pair of milling cutters engages the rail 11 and mills a
second set of matched facets, and a third pair of milling cutters
engage the rail 11 and mills a third set of matched facets. The
first set of matched facets may be located below the second set of
matched facets, and the second set of matched facets may be
positioned below the third set of matched facets. In one such
embodiment, the first set of matched facets is milled before the
second set of matched facets (as the re-profiling vehicle traverses
the rail), and the second set of matched facets is milled before
the third set of matched facets. Accordingly, in one embodiment, a
method of re-profiling a railway rail 11 comprises positioning a
plurality of milling cutters proximate to the rail 11 such that the
plurality of milling cutters sequentially mills sets of matched
facets from a lower portion of the rail to a higher portion of the
rail. Because the width of the rail being re-profiled will
generally be much less than the diameters of the milling cutters,
pairs of milling cutters will typically be spaced apart on one or
more re-profiling vehicles along a length of rail. For example,
milling cutters may be staggered along one or both sides of a rail.
Also, it will be understood that unpaired milling cutters (i.e.
milling cutters not part of a set) may be employed in the methods
and apparatuses according to the present disclosure. Accordingly,
in certain embodiments, one or more unpaired milling cutters may be
mounted on a carriage or other rail vehicle to mill portions or
segments of a profile into a rail in situ, and such carnage or
vehicle may or may not also include paired sets of milling cutters
mounted thereon.
[0072] In various embodiments, milling cutters used according to
the present disclosure may include cutting inserts comprising
uncoated cemented carbide grades, such as, for example. C6 carbide,
or coated cemented carbide grades, such as, for example, coated C6
carbide. Coated carbide grades may be selected from, e.g., PVD or
CVD coated carbides. In various alternate embodiments, milling
cutters used according to the present disclosure may include
cutting inserts comprising uncoated ceramic grades (for example,
Greenleaf.RTM. WG-300 material) or coated ceramic grades (for
example, Greenleaf.RTM. WG-600 material).
[0073] According to various embodiments, a face milling cutter
including a set of 8 cutting inserts mounted thereon may be rotated
on a milling cutter at 300 RPM and advance along a railway rail at
1 mph for at least 18,000 feet (ft). 27,000 ft, or farther before
requiring indexing or replacement of one or more of the cutting
inserts. In a further embodiment, because wear is generally
proportional to work performed by the cutting tool, a similar
milling cutter configuration comprising a load of 32 cutting
inserts may run at 300 RPM and advance along a railway rail at 4
mph for a distance of 108.000 ft (20.45 miles) before requiring
indexing or replacement of one or more of the cutting inserts.
[0074] As described above., another factor in regard to cutting
insert life is depth of cut. As disclosed herein, maintaining depth
of cut to around 0.005-0.010 inches may beneficially increase
cutting insert life as well as adequately re-profile railway rails
without significant removal of material that may otherwise
unacceptable shorten the operational life of the rail However, in
various embodiments, it may be desirable or necessary to increase
depth of cut beyond 0.010 inches, for example to 0.040 inches or
more. In certain embodiments, the method may involves controlling
the depth of cut of the cutting inserts to a depth no more than
0.040 inches, no more than about 0.010 inches, or between 0.005
inches and 0.010 inches.
[0075] Accordingly, unless stated otherwise, the present disclosure
is not limited to a 0.0010 inch depth of cut or any other depth of
cut described herein.
[0076] Also, as described above, one factor to consider in regard
to cutting insert life is facet width or width of cut. For example,
maintaining facet width on the rail to a minimum, such as 0.31
inches or less in some instances, may result in enhanced cutting
insert life. Also, for example, in certain embodiments the width of
cut may be limited to about 0.625 inches or less when milling a
segment or portion of a profile on a rail.
[0077] According to various embodiments, the thickness of cutting
inserts may beneficially increase the operational life of the
cutting inserts. For example, because the wear land will increase
dramatically as the cutting edge in one area progresses down the
length of the cutting insert, increasing a thickness of the cutting
inserts may allow further utilization all cutting edges.
[0078] In various embodiments, a milling cutter may be configured
to enhance cutting insert life in railway rail re-profiling
applications. For example, whereas a cutting insert comprising an
insert edge having a linear, e.g., wiper, portion extending a first
distance to an angled portion may lose operational life once the
linear portion has worn away, a cutting insert comprising a more
sweeping radii or an insert edge having a linear portion extending
a second distance, greater than the first, may result In additional
insert life. That is, when the linear portion is worn in one area
of the cutting insert edge, the actual cutting edge may move to a
fresh area of the Insert. In one embodiment, dimensions of a
cutting insert may comprise a width of 0.375 inches, a thickness of
0.25 inches, and length of 0.75 inches. Where the cutting edged is
located along the length of the insert, increasing the length of
the insert from 0.75 inches to 1.125 inches or more may provide
additional cutting insert life. For example, the cutting edge may
comprise an actual cutting edge. The actual cutting edge may
progressively move along the edge as it wears. In one embodiment, a
cutting edge of one or more of the cutting inserts may comprise an
actual cutting edge. The actual cutting edge may, in some
instances, may transition along the cutting edge from a first
position to a second position when the first position wears,
thereby increasing cutting insert life.
[0079] Those having ordinary skill in the art, on considering the
present description of certain embodiments, will appreciate that
the particular desired dimensions of a cutting insert may depend on
the desired application, such as the shape, form, location, or
environment of a railway rail. Therefore, unless stated otherwise,
the above dimensions are merely examples of cutting insert
dimensions.
[0080] As described above, in various embodiments, the milling
cutter may be positioned in an offset configuration with respect to
the rail. For example, 3 to 4.5 inches may separate the rotation
axis of the milling cutter from the work performed along a rail. In
various non-limiting embodiments, and using a 10 inch milling
cutter as a scalable reference, milling cutters may be positioned
at an offset of between 3.5 inches and 4.0 inches, or may be
positioned at an offset of about 3.75 inches. In certain
embodiments, the milling cutter may be positioned in an offset
orientation comprising a distance between 35% and 40% of the
milling cutter diameter. As also described above, in various
embodiments, a plurality of milling cutters may be positioned to
simultaneously and/or sequentially mill a rail profile. In one
embodiment, the milling cutters may define cutting angles between
0.degree. and about 55.degree. about the rail profile.
[0081] According to various embodiments, cutting inserts may be
supplied with various edge preparations. For example, edge
preparations may include 0.002-0.003 inch hone only and a
0.015-0.020 inch.times.20.degree. negative land with a 0.002-0.003
inch hone. In certain embodiments, reducing the rotational speed of
the milling cutter may significantly increase insert life. In one
embodiment, the rotational speed of the milling cutter may be
reduced and the feed rate or speed of traverse may be increased to
increase cutting insert life.
[0082] It will be appreciated that while the present disclosure may
provide exemplary milling cutter bodies defining 32 cutting insert
positions, it is contemplated that milling cutters equipped to
accept mere than or less than 32 cutting inserts may be used with
the methods and apparatuses of the present disclosure. For example,
the number of cutting inserts that may be mounted on a face milling
cutter is generally determined by the circumference of the
peripheral portion of the cutter body defining the insert positions
and/or the size of the cutting inserts. In various non-limiting
embodiments, the diameter of the milling cutter may be between 8
inches and 16 inches, or between 10 inches and 12 inches. In some
embodiments, milling cutters comprising diameters less than 10
inches, such as 4 inches, may be used alone or in combination with
other milling cutters comprising diameters that may be less than,
greater than, or equal to the milling cutter comprising less than a
10-inch diameter. It is contemplated that reduced diameter milling
cutter configurations may be beneficial for milling of difficult to
reach segments of rail profile, such as rail at transitions,
platforms, or grade crossings. It is also contemplated that milling
cutters comprising diameters greater than 10 inches may be used
alone or in combination with other milling cutters comprising
diameters less than, greater than, or equal to the milling cutter
comprising greater than a 10 inch diameter. It is contemplated that
increased diameter milling cutters may be used to increase speed or
operational life of various sets of cutting inserts. For example,
longer insert life spans may increase productivity and shorten rail
outage periods due to re-profiling because maintenance personnel
will not be required to interrupt the re-profiling process to index
or replace cutting inserts as frequently.
[0083] In the present description of embodiments, other than in the
operating examples or where otherwise indicated, all numbers
expressing quantities or characteristics of elements, products,
processing or test conditions or parameters, and the like are to be
understood as being modified in all instances by the term "about".
Accordingly, unless indicated to the contrary, any numerical
parameters set forth in the following description are
approximations that may vary depending upon the desired properties
one seeks to obtain in the apparatuses and methods according to the
present disclosure. At the very least, and not as an attempt to
limit the application of the doctrine of equivalents to the scope
of the claims, each numerical parameter should at least be
construed in light of the number of reported significant digits and
by applying ordinary rounding techniques.
[0084] This disclosure describes various elements, features,
aspects, and advantages of various embodiments of rail re-profiling
apparatus and methods, systems, and methods thereof. It is to be
understood that certain descriptions of the various embodiments
have been simplified to illustrate only those elements, features
and aspects that are relevant to a more clear understanding of the
disclosed embodiments, while eliminating, for purposes of brevity
or clarity, other elements, features and aspects. Any references to
"various embodiments," "certain embodiments," "some embodiments,"
"one embodiment" or "an embodiment" generally means that a
particular element, feature, and/or aspect described in the
embodiment is included in at least one embodiment. The phrases "in
various embodiments," "in certain embodiments." "in some
embodiments," "in one embodiment," or "in an embodiment" may not
refer to the same embodiment. Furthermore, the phrases "in one such
embodiment" or "in certain such embodiments," while generally
referring to and elaborating upon a preceding embodiment, is not
intended to suggest that the elements, features, and aspects of the
embodiment introduced by the phrase are limited to the preceding
embodiment; rather, the phrase is provided to assist the reader in
understanding the various elements, features, and aspects disclosed
herein and it is to be understood that those having ordinary skill
in the art will recognize that such elements, features, and aspects
presented in the introduced embodiment may be applied in
combination with other various combinations and sub-combinations of
the elements, features, and aspects presented in the disclosed
embodiments.
[0085] Although the foregoing description has necessarily presented
only a limited number of embodiments, those of ordinary skill in
the relevant are will appreciate that various changes in the
apparatuses and methods and other details of the examples that have
been described and illustrated herein may be made by those skilled
in the art, and all such modifications will remain within the
principle and scope of the present disclosure as expressed herein
and in the appended claims. For example, although the present
disclosure has necessarily only presented a limited number of
embodiments of rail re-profiling apparatuses and methods, it will
be understood that the present disclosure and associated claims are
not so limited. Those having ordinary skill will readily identify
additional rail re-profiling apparatuses and methods and may design
and build and use additional rail re-profiling apparatuses and
methods along the lines and within the spirit of the necessarily
limited number of embodiments discussed herein. It is understood,
therefore, that the present invention is not limited to the
particular embodiments or methods disclosed or incorporated herein,
but is intended to cover modifications that are within the
principle and scope of the invention, as defined by the claims. It
will also be appreciated by those skilled in the art that changes
could be made to the embodiments and methods discussed herein
without departing from the broad inventive concept thereof.
* * * * *