U.S. patent application number 11/261709 was filed with the patent office on 2006-05-11 for railway ballast excavator having inclined portion.
This patent application is currently assigned to RWF Bron. Invention is credited to Ronald Hall.
Application Number | 20060096131 11/261709 |
Document ID | / |
Family ID | 36283148 |
Filed Date | 2006-05-11 |
United States Patent
Application |
20060096131 |
Kind Code |
A1 |
Hall; Ronald |
May 11, 2006 |
Railway ballast excavator having inclined portion
Abstract
A railway ballast excavating apparatus comprising a guide frame
having an endless excavating chain mounted thereon, the guide frame
having a first portion for insertion beneath the railway tracks and
a second portion parallel and inclined with respect to the first
portion, the first portion for excavating ballast and the second
portion for elevating the excavated ballast in order to deposit the
excavated ballast in a pile adjacent the railway tracks. The
apparatus is powered by a rubber-wheeled motive vehicle and can be
advantageously lifted from the railway tracks in the event of an
oncoming train.
Inventors: |
Hall; Ronald; (Woodstock,
CA) |
Correspondence
Address: |
ANISSIMOFF & ASSOCIATES;RICHMOND NORTH OFFICE CENTRE
SUITE 201
235 NORTH CENTRE RD.
LONDON
ON
N5X 4E7
CA
|
Assignee: |
RWF Bron
|
Family ID: |
36283148 |
Appl. No.: |
11/261709 |
Filed: |
October 31, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60624604 |
Nov 3, 2004 |
|
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|
Current U.S.
Class: |
37/104 |
Current CPC
Class: |
E02F 3/08 20130101; E01B
27/04 20130101; E02F 3/10 20130101; E02F 5/22 20130101; E02F 9/022
20130101 |
Class at
Publication: |
037/104 |
International
Class: |
E02F 5/22 20060101
E02F005/22 |
Claims
1. An excavating apparatus for excavating ballast material from
beneath a railway track and for elevating the excavated ballast
material, the apparatus comprising: a) a frame having a set of
railway wheels thereunder; and, b) an excavating unit laterally
adjacent the frame, the excavating unit comprising an endless
excavating chain mounted on a guide frame having a first portion
and a second portion parallel to and inclined from the first
portion, the second portion having an inclination angle relative to
the first portion, the second portion for elevating and depositing
excavated ballast in a pile adjacent the railway track.
2. The apparatus according to claim 1, wherein the frame comprises
a horizontal slide oriented transversely to the railway track and
wherein the excavating unit is mounted to the horizontal slide.
3. The apparatus according to claim 1, wherein the excavating unit
comprises a vertical slide permitting vertical movement of the
guide frame.
4. The apparatus according to claim 1, wherein the excavating unit
comprises a knuckle comprising a vertical pivot axis, the knuckle
operable to pivot the guide frame about the vertical pivot
axis.
5. The apparatus according to claim 1, wherein the guide frame
comprises a plurality of debris clearing holes for reducing debris
accumulation within the guide frame.
6. The apparatus according to claim 1, wherein the frame further
comprises a connection means for releasable connection with a
motive vehicle.
7. The apparatus according to claim 6, wherein the connection means
comprises a cradle for receiving an articulated arm of the motive
vehicle
8. The apparatus according to claim 7, wherein the cradle engages
with an excavating bucket attached to the articulated arm and
causes longitudinal movement of the apparatus along the track in
response to movement of the motive vehicle along the track.
9. The apparatus according to claim 1, wherein the frame further
comprises a connection means for releasable connection with a
motive vehicle and wherein the excavating unit comprises a
hydraulic motor for driving the excavating chain, the hydraulic
motor releasably connected to a source of fluid power on the motive
vehicle, the excavating unit powered solely using the source of
fluid power on the motive vehicle.
10. The apparatus according to claim 1, wherein the apparatus has a
total weight less than or equal to 11,000 lbs.
11. The apparatus according to claim 1, wherein the second portion
of the guide frame is inclined with respect to the first portion of
the guide frame by an inclination angle of from 10 to 45
degrees.
12. The apparatus according to claim 1, wherein the second portion
of the guide frame is inclined with respect to the first portion of
the guide frame by an inclination angle of from 15 to 30
degrees.
13. The apparatus according to claim 1, wherein the second portion
of the guide frame is inclined with respect to the first portion of
the guide frame by an inclination angle of from 20 to 23
degrees.
14. The apparatus according to claim 1, wherein the second portion
of the guide frame is inclined with respect to the first portion of
the guide frame by an inclination angle of about 22 degrees.
15. The apparatus according to claim 1, wherein the excavating
chain comprises a plurality of excavating links, each excavating
link having a first and second pair of vertically spaced apart
horizontal joining plates, each pair of spaced apart joining plates
comprising concentrically aligned through-holes, the excavating
chain further comprising a joining link interspersed between each
excavating link, each joining link comprising a spherical bearing
at each end thereof located between the spaced apart joining
plates, each spherical bearing having an aperture concentrically
aligned with the through-holes for receiving a pin connecting the
excavating link with the joining link, each pin having a vertical
axis about which the excavating link is permitted to rotate
relative to the joining link, each spherical bearing permitting
angular deflection of the vertical axis in response to movement of
the bearing from the first portion of the guide frame to the second
portion of the guide frame.
16. The apparatus according to claim 1, wherein the excavating
chain comprises a plurality of excavating links, each excavating
link having an outwardly projecting excavating lug having an
inclined row of vertically and horizontally spaded apart excavating
teeth, each inclined row having a row angle with respect to the
direction of movement of the excavating chain.
17. The apparatus according to claim 16, wherein the row angle is
from 10 to 45 degrees.
18. A system for excavating ballast material from beneath a railway
track comprising: a) a motive vehicle comprising a rubber-wheeled
excavator having a set of selectively deployable railway wheels and
an articulated arm; b) an excavating apparatus comprising a frame
having a set of railway wheels thereunder and comprising a
connection means for releasable connection with the articulated arm
of the motive vehicle, the excavating apparatus further comprising
an excavating unit laterally adjacent the frame, the excavating
unit comprising an endless excavating chain mounted on a guide
frame having a first portion and a second portion parallel to and
inclined from the first portion, the second portion having an
inclination angle relative to the first portion, the second portion
for elevating and depositing excavated ballast in a pile adjacent
the railway track; and, c) wherein the motive vehicle is operable
to move the excavating apparatus longitudinally along the track, to
lift the excavating apparatus from the track and deposit the
excavating apparatus adjacent the track, and to drive off of the
track by selectively raising the railway wheels.
19. A method of excavating ballast material from beneath a railway
track comprising: a) providing an excavating apparatus comprising a
laterally adjustable excavating unit comprising an endless
excavating chain mounted on a guide frame having a first portion
and a second portion parallel to and inclined from the first
portion, the second portion having an inclination angle relative to
the first portion; b) transversely positioning the first portion of
the excavating unit at a first operative position beneath the
track; and, c) operating the excavating unit to remove ballast
material from beneath the track using the first portion, to elevate
the ballast material using the second portion, and to deposit the
ballast material in a first pile adjacent the railway track.
20. The method according to claim 19, wherein the method further
comprises transversely positioning the first portion of the
excavating unit at a second operative position beneath the track
then operating the excavating unit both to remove remaining ballast
material from beneath the track and to deposit the remaining
ballast material in a second pile adjacent the first pile.
Description
FIELD OF THE INVENTION
[0001] The invention relates to the excavation of ballast from
beneath railway tracks and the simultaneous elevation and piling of
excavated ballast alongside the railway track. More particularly,
the invention relates to an apparatus and method of excavating
railway ballast for the purpose of repairing small sections of
track using a mobile endless-chain type excavator having a
horizontal portion for excavating the ballast and an inclined
portion for elevating the excavated ballast.
BACKGROUND OF THE INVENTION
[0002] Railway lines generally comprise a set of spaced apart rails
mounted on a plurality of transversely placed railway ties that are
located upon a bed of compacted ballast material. The rails, ties
and ballast must be routinely replaced and machines for removing,
cleaning and replacing ballast, such as described in U.S. Pat. No.
5,090,484, are known in the art. However, these machines are large
and not particularly well suited to removing ballast from
relatively small sections of track or for repairing a portion of a
track.
[0003] U.S. Pat. No. 6,862,822, issued on Mar. 8, 2005, discloses a
mobile railway track repair apparatus having an endless-chain
excavator mounted on the end of an articulated arm of a
conventional excavating vehicle. The endless chain conveyor may be
positioned at any desired angle or orientation beneath the track
and may be readily replaced by a conventional excavating bucket.
This apparatus is limited in that ballast material can only be
excavated from the immediate vicinity of the excavating vehicle
and, since these vehicles are quite heavy, this can cause track
instability resulting in misalignment and the need for extensive
repair. Moreover, when the excavator is fully inserted beneath the
tracks, excavated ballast material accumulates immediately behind
the excavator and must be dislodged in order to remove the
excavator. This spreads the material around in the vicinity of the
tracks, making it difficult to collect and remove at a later time.
Although the apparatus is suited for small track repairs, the
apparatus cannot be operated continuously along a small section of
track, such as a siding.
[0004] U.S. Pat. No. 3,967,395, issued on Jul. 6, 1976, discloses
an endless chain excavator mounted to the front of a forklift
vehicle. The excavator can move vertically along a vertical slide
and can be rotated about a vertical axis. The vehicle must be
driven toward the tracks from the side thereof in order to insert
the excavator beneath the tracks and must be re-positioned when the
ballast material has been removed. The excavated material
accumulates behind the apparatus; the material must therefore be
dislodged as the apparatus is removed, with the disadvantages
described above, and driven over by the forklift vehicle as the
apparatus is advanced beneath the track. The apparatus is not
suitable to continuous operation along a small section of
track.
[0005] U.S. Pat. No. 3,436,848, issued Apr. 8, 1969, discloses an
endless chain excavator apparatus mounted on a railway vehicle for
continuously removing ballast along a small section of track. The
excavator may be moved transversely to the track using a horizontal
screw mechanism and may be pivoted about a vertical axis to move
from an orientation parallel to the tracks to an orientation
perpendicular to the tracks. The apparatus is vertically moveable
using a parallelogram linkage. The chain excavator extends under
the full width of the tracks and can be used to excavate ballast
from beneath an adjacent set of tracks, such as a siding. However,
the apparatus suffers in that accumulated material is deposited
immediately adjacent the end of the chain excavator and hampers
excavation of additional material. The excavated material must
therefore be manually dislodged or accumulated simultaneously with
excavation using a separate apparatus adapted for that purpose.
This is operationally cumbersome and requires additional labour and
equipment. Moreover, the apparatus is vehicle mounted and neither
the apparatus nor the vehicle can be readily removed from the
railway tracks. This can pose a problem in the event of an oncoming
train, even if the train is on an adjacent set of tracks.
[0006] U.S. Pat. No. 6,698,115, issued on Mar. 2, 2004, discloses a
mobile track maintenance machine having a clearing chain for
excavating bulk material that has a universal joint between each
link of the chain. The chain has an ejection end positioned above a
receiving end of a conveyor belt for transporting the excavated
ballast and is guided to the ejection end in a curved guide track.
The ejection end is oriented rearwardly of the excavating section
of the chain and does not discharge material alongside the railway
track in a direction parallel with the excavating section. The
ballast material is not deposited in a pile but instead is
simultaneously transported with the conveyor belt to a bulk
material loading wagon coupled to the machine. This requires
periodic emptying of the bulk material loading wagon and is
operationally cumbersome as compared with simply depositing the
material in a pile. Also, the excavating chain apparatus is mounted
to a railway vehicle and neither the apparatus nor the vehicle can
be readily removed from the track in the event of an oncoming
train.
[0007] It would be desirable to provide an apparatus for excavating
railway ballast from beneath a set of railway tracks that may be
moved along a railway track for continuous excavation of a small
section of track and that is readily disconnected from the motive
vehicle in order to permit both the apparatus and the vehicle to be
removed from the set of tracks in the event of an oncoming train.
It would be further desirable to provide a railway ballast
excavating apparatus that also elevates the excavated material to
facilitate pile formation alongside the track to alleviate the need
for simultaneous removal of excavated ballast while permitting the
ballast to be readily removed at a later time. However, no such
apparatus is currently available and the need currently exists for
an improved railway ballast excavating apparatus having some or all
of the foregoing features.
SUMMARY OF THE INVENTION
[0008] According to the present invention, there is provided an
excavating apparatus for excavating ballast material from beneath a
railway track and for elevating the excavated ballast material, the
apparatus comprising: a frame having a set of railway wheels
thereunder; and, an excavating unit laterally adjacent the frame,
the excavating unit comprising an endless excavating chain mounted
on a guide frame having a first portion and a second portion
parallel to and inclined from the first portion, the second portion
having an inclination angle relative to the first portion, the
second portion for elevating and depositing excavated ballast in a
pile adjacent the railway track.
[0009] According to the present invention, there is further
provided a system for excavating ballast material from beneath a
railway track comprising: a motive vehicle comprising a
rubber-wheeled excavator having a set of selectively deployable
railway wheels and an articulated arm; an excavating apparatus
comprising a frame having a set of railway wheels thereunder and
comprising a connection means for releasable connection with the
articulated arm of the motive vehicle, the excavating apparatus
further comprising an excavating unit laterally adjacent the frame,
the excavating unit comprising an endless excavating chain mounted
on a guide frame having a first portion and a second portion
parallel to and inclined from the first portion, the second portion
having an inclination angle relative to the first portion, the
second portion for elevating and depositing excavated ballast in a
pile adjacent the railway track; and, wherein the motive vehicle is
operable to move the excavating apparatus longitudinally along the
track, to lift the excavating apparatus from the track and deposit
the excavating apparatus adjacent the track, and to drive off of
the track by selectively raising the railway wheels.
[0010] According to the present invention, there is yet further
provided a method of excavating ballast material from beneath a
railway track comprising: providing an excavating apparatus
comprising a laterally adjustable excavating unit comprising an
endless excavating chain mounted on a guide frame having a first
portion and a second portion parallel to and inclined from the
first portion, the second portion having an inclination angle
relative to the first portion; transversely positioning the first
portion of the excavating unit at a first operative position
beneath the track; and, operating the excavating unit to remove
ballast material from beneath the track using the first portion, to
elevate the ballast material using the second portion, and to
deposit the ballast material in a first pile adjacent the railway
track.
[0011] The frame may comprise a vertical slide for positioning the
excavating unit at a desired height. The frame may comprise a
knuckle having a vertical pivot axis therethrough that may be
operable using, for example, hydraulic cylinders to open and close,
thereby pivoting the guide frame of the excavating unit about the
vertical pivot axis. This allows the guide frame to be moved from a
transport position parallel to the tracks to a working position
transverse of the tracks. The frame may further comprise a
horizontal slide oriented transversely to the railway track and the
excavating unit may be mounted to the frame to permit the
excavating unit to be placed at any desired transverse position
relative to the railway track. The frame may further comprise a
tilt mechanism that permits the guide frame to adopt any desired
angular orientation relative to horizontal. This permits the guide
frame to be inserted beneath the tracks in one orientation, then
allows the orientation to be adjusted in response to excavating
conditions, obstacles, etc. The frame may include any of the
foregoing features alone or in combination and permits the
excavating unit to be adjusted in height, horizontal position,
parallel or transverse relationship with the tracks, and/or angular
orientation relative to the tracks.
[0012] The apparatus lacks its own source of motive power and is
moved along the railway tracks using a motive vehicle. The motive
vehicle is preferably a rubber-wheeled excavator having a set of
selectively deployable railway wheels. The motive vehicle may be
connected to the apparatus using one or more of a variety of
different means, such as a tow bar, push bar, etc. Preferably, the
motive vehicle is releasably connected to the apparatus using a
connection means that is adapted for receiving an articulated arm
of the motive vehicle. The connection means may comprise a cradle
for receiving an excavating bucket attached to the end of the
articulated arm. The cradle may comprise fore and aft transverse
frame members that engage with the excavating bucket when the
motive vehicle is moved along the tracks to cause a corresponding
movement of the apparatus. The cradle may include clamping means
for securing the bucket within the cradle or the bucket may be
unsecured and maintained within the cradle through downward
pressure applied using hydraulic cylinder mechanisms of the
articulated arm.
[0013] The apparatus may be powered using a hydraulic motor or
motors that may be releasably connected to a source of fluid power
on the motive vehicle using suitable fluid conduits. The releasable
connection between the articulated arm and the frame and between
the source of fluid power and the hydraulic motor(s) permits the
motive vehicle to be readily de-coupled from the apparatus. In the
event of an oncoming train, it is often desirable to remove the
apparatus from the tracks to prevent potential damage to either the
train, the apparatus, or the motive vehicle. In the prior art, it
has been necessary to move the apparatus along the track until a
siding has been reached that permits the apparatus and motive
vehicle to be moved off-line. In the present invention, the
releasable connections permit the apparatus to be readily lifted
from the track using the articulated arm of the motive vehicle and
set alongside the tracks. The railway wheels may then be raised,
permitting the rubber-wheeled excavator to be moved off of the
tracks alongside the apparatus. When the train has passed, the
apparatus may be again positioned on the tracks using the excavator
and work may be resumed. This saves a tremendous amount of wasted
time as compared with prior art ballast excavating machines.
[0014] To facilitate removal of the apparatus from the track, the
apparatus may be equipped with a central lifting lug that provides
a central connection point for the articulated arm. The apparatus
may be equipped with ballast weights on the opposite side of the
frame from the excavating unit to provide stability during cutting
operations. These weights may be removed prior to lifting the
apparatus from the tracks to reduce the overall weight being
lifted. The allowable maximum weight of the apparatus depends upon
the lifting capabilities of the motive vehicle; however, it has
been found that for most excavating vehicles of the size utilized
in railway ballast excavating operations a maximum total weight of
11,000 lbs is desirable. It is desirable that the apparatus be
somewhat balanced while lifting and the frame may be devised in
such a manner as to balance the weight vis-a-vis the position of
the central lifting lug so that the apparatus does not tip during
lifting.
[0015] During ballast excavation, debris may have a tendency to
accumulate within the guide frame behind the excavating chain. The
apparatus may desirably be equipped with debris clearing holes in
the guide frame to permit the debris to naturally fall out of the
guide frame and to permit debris to be readily cleared from the
guide frame using a high-pressure water spray or jet of compressed
air. The accumulation of debris can significantly affect the
overall weight and balance of the apparatus and the removal of
debris is desirable in facilitating the removal of the apparatus
from the railway tracks.
[0016] In operation, the excavating unit is first moved to a
desired location with the guide frame of the excavating unit
oriented parallel to the railway track. The horizontal slide is
then operated to move the excavating unit transversely away from
the track. The excavating unit can then be lowered to a desired
height relative to the track and the excavating chain can begin to
operate. The angular orientation of the guide frame may optionally
be adjusted if desired. The knuckle is then used to pivot the
excavating unit about a vertical pivot axis, bringing the guide
frame from an orientation parallel with the tracks to an
orientation transverse to the tracks. As the excavating unit
engages the ballast during pivoting movement, ballast is removed
using the excavating chain and the guide frame is permitted to be
inserted beneath the tracks. The motive vehicle is then operated in
reverse to move the apparatus slowly along the railway tracks with
the excavating chain continuously removing ballast material as the
apparatus travels.
[0017] In the prior art, excavated material quickly accumulates in
the vicinity of the outward end of the guide frame, which
interferes with the rate of excavation, increases the likelihood
for damage to the apparatus, and limits the amount of material that
can be removed in each transit of the apparatus along the tracks.
To overcome these disadvantages, the present invention is equipped
with a first portion and a second portion that is parallel to the
first portion but inclined thereto. This second portion serves to
elevate the excavated material and deposits the excavated material
in a pile alongside the railway track. The angle of inclination in
some part depends upon the amount of material desired to be removed
in a single transit of the apparatus along the tracks. If the full
width of the tracks is to be excavated in a single transit (which
normally results in a first portion length in excess of 13 feet),
then a greater angle may be required as compared with an excavating
unit having a shorter first portion. However, larger inclination
angles have the disadvantage of losing more of the excavated
material while elevating, causing the pile to be spread out
alongside the tracks and generally reducing the efficacy of the
second portion. It has surprisingly been found that only a small
angle is required for proper pile formation, even during full-width
cutting operations. The second portion may be inclined with respect
to the first portion at an angle of from 10 to 45 degrees,
preferably from 15 to 30 degrees, more preferably from 20 to 23
degrees, yet more preferably about 22 degrees.
[0018] A further benefit of using the smallest allowable
inclination angle is found in the excavating chain. Since the
excavating chain is required to deflect upwardly as it travels from
the first portion to the second portion, the excavating chain may
be provided with one or more universal joints between each link.
The universal joints may comprise a semi-spherical eye within a
complementary bearing race that permits the normally vertical pivot
axis between each link to deflect to an angular orientation as the
joint passes from the first portion to the second portion. As the
inclination angle of the second portion increases, so too does the
required deflection of the universal joint. In order to keep the
chain as robust as possible, it is therefore desirable to utilize
the smallest allowable inclination angle in order to reduce the
required deflection of the universal joint. The use of a joining
link having two universal joints between each excavating link is
desirable in that it allows the deflection angle of each individual
universal joint to be further reduced.
[0019] Each excavating link of the excavating chain may comprise an
outwardly projecting excavating lug having a row of horizontally
and vertically spaced apart excavating teeth. The individual teeth
may be angled with respect to one another. The row of teeth may
form an inclined row angle relative to the direction of movement of
the excavating chain. The row angle may correspond to the
inclination angle of the second portion so that when the excavating
link is on the second portion, the row is substantially horizontal.
This facilitates elevation of excavated material using the second
portion, thereby reducing the tendency toward pile spreading and
further reducing the allowable inclination angle. The row angle may
be from 10 to 45 degrees, preferably from 15 to 30 degrees, more
preferably from 20 to 23 degrees, yet more preferably about 22
degrees.
[0020] In the present invention, it is desirable that the second
portion is substantially aligned with the first portion. This
causes the second portion to eject material transversely of the
railway track during operation of the excavating unit. If the
second portion were not parallel with the first portion, the
excavated material would have a tendency to be ejected from the
first portion and not elevated using the second portion. Prior art
devices have utilized a curved guide shield to prevent this
ejection of material; however, a guide shield simply causes the
excavated material to accumulate at the curve, reducing the
throughput of the excavating apparatus and increasing the
likelihood for excavated material to become lodged, resulting in
mechanical failure. By keeping the second portion substantially
parallel with the first portion, the need for any guide shield is
reduced and desirably eliminated.
[0021] Further features of the invention will be described or will
become apparent in the course of the following detailed
description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] In order that the invention may be more clearly understood,
embodiments thereof will now be described in detail by way of
example, with reference to the accompanying drawings, in which:
[0023] FIG. 1 is a side view of an embodiment of a system according
to the present invention in operation on a railway track;
[0024] FIG. 2 is a top view of an embodiment of an apparatus
according to the present invention showing the excavating unit in
the transport and operating positions;
[0025] FIG. 3 is a side view of the apparatus showing the
excavating unit in the raised and lowered positions;
[0026] FIG. 4 is a front view of the apparatus showing the
excavating unit in the transport position;
[0027] FIG. 5 is a front view of the apparatus showing the
excavating unit in the operating position while forming a pile of
excavated material alongside the railway track;
[0028] FIG. 6 is a side cut-away view of an embodiment of an
excavating chain for use with an apparatus according to the present
invention;
[0029] FIG. 7a is a top view of the apparatus in operation at a
first position beneath the railway track while forming a first pile
of excavated material; and,
[0030] FIG. 7b is a top view of the apparatus in operation at a
second position beneath the railway track while forming a second
pile of excavated material.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0031] Throughout the drawings, like indicia will be used to refer
to like features of the drawings. All indicia present on a given
drawing need not necessarily be described with reference to that
particular drawing.
[0032] Referring to FIG. 1, an apparatus according to the present
invention comprises a frame 1 having a set of railway wheels 2
thereunder for engagement with rails 3 supported by railway ties 4.
An excavator 5 has a set of rubber ground wheels 6, a set of
selectively deployable railway wheels 7 and an articulated arm 8
with an excavating bucket 9 at one end thereof that is releasably
engaged within a cradle 10 of the frame 1. The cradle 10 comprises
fore and aft frame transverse frame members so that when the
excavator 5 travels along the tracks, engagement of the bucket 9
against the frame members causes corresponding movement of the
apparatus. The excavator 5 is supplementary connected to the frame
by means of a tow bar 11. The apparatus lacks its own source of
motive power and relies upon the excavator 5 for movement along the
tracks.
[0033] The frame 1 further comprises a central lifting lug 12. In
the event of an oncoming train, the bucket 9 is disengaged from the
cradle 10 and the articulated arm 8 is connected to the lifting lug
12 using chains or other suitable means in order to lift and remove
the apparatus from the tracks. The railway wheels 7 are then
selectively raised and the rubber wheels 6 are used to maneuver the
excavator 5 alongside the tracks. In order to reduce the overall
weight of the apparatus, frame cutaways 13 are provided and
strategically positioned on the frame in order to balance the
weight of the apparatus about the lifting lug 12. In the embodiment
shown, the weight of the apparatus is less than or equal to 11,000
lbs.
[0034] Referring now to FIG. 2, the apparatus is shown in top view.
An excavating unit, show generally at 14, comprises a guide frame
15 over which an endless excavating chain 16 passes. The excavating
chain 16 is equipped with excavating lugs 17, only some of which
are shown, that extend outwardly from the excavating chain. The
excavating unit 14 is mounted to the frame 1 by way of a knuckle 18
having a vertical pivot axis passing through pivot pin 19. The
knuckle 18 is mounted to a horizontal slide 20 that moves within a
slide sleeve 21. The combination of the knuckle 18 and the slide 20
permit the excavating unit to adopt a transport position (denoted
as A) close to the frame 1, an extended position (denoted as B)
wherein the excavating unit 14 is transversely spaced apart from
the frame, and an operating position (denoted as C) wherein the
excavating unit 14 is pivoted about the pivot pin 19 using the
knuckle 18 to move into a transverse orientation for excavating
ballast material from beneath the railway tracks.
[0035] Iron ballast weights 22 are provided on the side of the
frame 1 opposite the excavating unit 14 to stabilize the unit
during operation; the ballast weights may increase the overall
weight of the apparatus past 11,000 lbs and are normally removed
prior to lifting the apparatus from the tracks. A hydraulic motor
23 is provided as part of the excavating unit 14 for powering the
excavating chain 16 in its passage about the guide frame 15. The
hydraulic motor 23 is releasably connected to a source of fluid
power (eg: hydraulic fluid pump) on the motive vehicle (not shown)
and is disconnected prior to lifting the apparatus from the tracks.
The cradle 10 is present on both the front and rear of the
apparatus; this permits the excavating unit to be positioned on
either side of the railway track and permits the apparatus to be
towed in either direction.
[0036] Referring to FIG. 3, the excavating unit 14 is shown mounted
to a vertical slide 24. This permits the excavating unit to be
moved from a raised transport position (denoted as A) to a lowered
position (denoted as D) that is either extended or un-extended. The
horizontal slide 20 moves within sleeve 21 to cause extension or
retraction of the excavating unit 14. The knuckle 18 comprises a
hydraulic knuckle cylinder 25 that is extended or retracted to
cause pivoting movement of the excavating unit 14 about the
vertical axis of the pivot pin 19. The guide frame 15 comprises a
first portion 26 and a second portion 27 that is upwardly inclined
with respect to the first portion with an inclination angle of
about 22 degrees. When the first portion 26 is inserted
transversely beneath the railway tracks and the hydraulic motor 23
is used to drive the endless excavating chain about the guide frame
15, ballast material excavated using the first portion is elevated
using the second portion and ejected at the exit end 28 of the
second portion 27 to ultimately be deposited in a pile adjacent the
railway track (not shown). The angular orientation of the
excavating unit 14 is adjusted by extension or retraction of angle
cylinder 31. This causes the excavating unit 14 to pivot about a
horizontal pivot axis passing through horizontal pivot 32. The
angular orientation of the excavating unit can be adjusted by up to
+/-15 degrees from horizontal in order to accommodate excavation
around railway switches, upon steep embankments, or in other
locations where it is difficult to obtain direct horizontal
access.
[0037] Referring to FIGS. 4 and 5, the excavating unit 14 is shown
in the transport position (FIG. 4) parallel to the railway tracks 3
and is also shown in the operating position (FIG. 5) transverse to
the railway tracks 3 and inserted beneath the railway ties 4 in
order to remove ballast material thereunder. The second portion 27
of the guide frame 15 is inclined with respect to the first portion
26 by an angle of about 22 degrees. This advantageously provides
sufficient elevation of the excavated material to permit pile
formation without undue loss of material from the excavating chain
that could occur with overly steep inclination. The second portion
27 is parallel to the first portion 26 when seen in top view and
inclined with respect to the first portion 26 when seen in front or
side views. This co-alignment of the two portions reduces the
likelihood of excavated material being expelled at the inflection
between the two portions and obviates the need for guides and
shields for keeping material on the excavating chain during
elevation. Of course, guides and shields may be provided for
operator safety purposes, however these guides are not normally of
the robust nature needed in maintaining excavated material on the
chain during elevation. Substantially all of the excavated material
leaves the excavating unit after being elevated to the exit end 28
of the second portion 27 and is deposited in a pile alongside the
railway track. The formation of a pile is advantageous in that it
allows for subsequent retrieval and/or replacement of the excavated
material and spaces the excavated material apart from the track to
permit repairs or other work to be more easily conducted. Bumpers
29 are provided on the frame 1 above the railway wheels 2 to
mitigate damage to the frame or motive vehicle upon inadvertent
impact. The forward frame member 30 of the cradle 10 engages with
the bucket of the motive vehicle (not shown in FIG. 4) to cause
movement of the apparatus along the tracks in response to travel of
the motive vehicle.
[0038] Referring to FIG. 6, an excavating chain comprises a
plurality of excavating links 33 interspersed with joining links
34. Each excavating link 33 comprises an outwardly extending
excavating lug 41 to which a plurality of excavating teeth 42 are
mounted. The excavating teeth 42 are horizontally and vertically
spaced apart and form an inclined row having a row angle that is
opposite in direction to the inclination angle of the second
portion 27 relative to the first portion 26. The row angle is
generally from 10 to 45 degrees. The excavating teeth 42 are
splayed apart relative to one another as an aid both in excavating
and elevating ballast material.
[0039] Each excavating link 33 further comprises a pair of
vertically spaced apart plates 35 having a pair of vertically
aligned concentric holes 36. Each joining link 34 has a universal
joint (generally indicated at 40) at each end comprising a
semi-spherical swivel bearing 38 received within a ball race 39 and
having an aperture concentrically aligned with the holes 36 for
receiving a link pin 37 inserted therethrough. The link pin 37
permits the excavating link 33 to rotate relative to the joining
link 34 about a vertical axis passing through the link pin as the
excavating chain 16 travels endlessly about the guide frame 15. As
the universal joint 40 passes from the first portion 26 to the
second portion 27, the swivel bearing 38 moves within the ball race
39, permitting the joining link 34 to angularly deflect relative to
the excavating link 33. The vertical spacing of the plates 35
corresponds to the inclination angle of the second portion 27
relative to the first portion 26 in order to permit sufficient
deflection. The permissible deflection of each end of the joining
link 34 is normally equally to at least half of the total
inclination angle. As the excavating link 33 moves onto the second
portion 27, the link pin 37 and the vertical pivot axis passing
therethrough adopt the inclination angle of the second portion and
the bearing 38 again moves within the ball race 39 to restore a
substantially parallel relationship between the plates 35 and the
joining link 34.
[0040] Referring to FIGS. 7a and 7b, the excavating unit 14 is
shown in a first operating position (FIG. 7a) and a second
operating position (FIG. 7b). In the first operating position, the
excavating unit 14 is inserted approximately half-way beneath the
railway tracks 3 and deposits excavated material in a first pile 43
at a first spaced apart location from the railway tracks. After the
excavating unit 14 is operated along the section of tracks to form
the first pile, the apparatus is returned to the beginning of the
section of tracks being worked on and re-inserted to a second
operating position across the full-width of the railway tracks 3.
As the apparatus is operated in the second position, a second pile
44 is formed inwardly adjacent the first pile 43. This method of
operation of the apparatus is particularly advantageous in
situations where a large quantity of material is being removed from
beneath the tracks, as the height of the pile might exceed the
height of the exit end 29. By creating two piles 43 and 44, an
excavating unit 14 having a relatively small inclination angle can
still be used to remove a large quantity of material from beneath
the tracks.
[0041] Other advantages which are inherent to the structure are
obvious to one skilled in the art. The embodiments are described
herein illustratively and are not meant to limit the scope of the
invention as claimed. Variations of the foregoing embodiments will
be evident to a person of ordinary skill and are intended by the
inventor to be encompassed by the following claims.
* * * * *