Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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The present invention relates to improvements in a
moblle machine for compacting ballast o a ballast bed
supporting a track consisting o two rails fastened to ties
resting on the ballast, and more particularly to a track
tamping, leveling and lining machine used for this purpose.
A known machine of this type comprises a machine frame,
undercarriages supporting the machine frame on the track
rails for movement in an operating direction, a ballast
tamping unit vertically movably mounted on the machine frame
and including pairs of reciprocable and vibratory tamping
tools arranged to tamp ballast under respective ones of the
ties upon immersion of the tamping tools in the ballast when
the tamping unit is vertically moved, a track correction unit
mounted on the machine frame forwardly of the tamping unit in
the operating direction and a track correction reference
system for controlling the track correction unit. A track
stabilization unit may be mounted on the machine frame and
this unit includes a chassis, guide roller means firmly
holding the chassis in engagement with the track rails and
guiding the chassis along the track upon movement of the
machine frame in the operating direction, vibrator means for
imparting essentially horizontal vibrations to the trackl and
power drive means connecting the chassis to the machine frame
and arranged to impart essentially vertical load forces to
the chassis. The machine may have control means Eor
operating the ballast tamping, track correction and track
stabilization units.
A track tamping and leveling machine of this general
type has been disclosed, for example, in U.S. patent No.
3,926,123, dated December 16, 1975. This machine has a frame
supported on
two undercarriages and having a frame portion overhanging
the front undercarriage. The tamping unit is mounted on the
overhanging frame portion and the track stabîli~ation unit is
mounted on the machine rame between the two undercarriages
rearwardly of the tamping unit in the operating direction. With
this machine~ the track is brought to the desired level, is fixed
at this level by tamping the ballast under the track supporting
ties and the position of the leveled track is then stabilized.
According to U. S. patent No. 4~ 046~ 078r dated September 6,
1977, a mobile machine ~rame supporting a track stabilization
unit between two undercarriages is coupled to a mobile track
tamping, leveling and lining machine for stabilizing the track
after the track has been leveled, lined and tamped. During the
dynamic track stabilization effected with these prior art
machinesr the previously tamped ballast is 50 fluidized as to
become denser, thus reducing the volume of the ballast bed and
causing the trac~ to sink to a lower level. This anticipates the
kind of ballast settling occurring normally under train traffic
subsequent to track tamping operations and enhances the
resistance of the tamped ties to transverse movement relative to
the ballast bed. Since the track stabilization unit chassis is
downwardly pressed while being vibrated horizontally in a
direction transverse to the track, it causes the firmly gripped
track to be embedded in the fluidized ballast against lateral
movement of the ties while the ballast is further densified. In
this manner, the tamped ballast is further compacted under the
ties and at their ends, which reduces the ballast volume and
lowers the level of the track supported thereon. This type o~
track stabilization has been very successful in practice and has
greatly increased the durability of a corrected track position.
It is the primary object oE this invention further to
improve such track stabilization apparatus by simplifying
their structure and enhancing their eectiveness. With the
apparatus of the invention, a single and unitary machine can
obtain an almost ideal, stable ballast and track condition
attainable heretofore only by means of a high-efficiency
tamper equipped with the most up to-date tooling and a
separate modern track stabilization apparatus, both used
under the most favorable operating conditions.
The above and other objects are accomplished according
to the invention in a mobile machine of the first described
type by mounting the track stabilization unit substantially
in the same area of the machine frame as the tamping unit and
providing control means for a~tomatically and selectively
operating the ballast tamping, track correction and track
stabilization units in a selected operating cycleO The
stabilization units chassis includes an elongated carrier
associated with each track rail and arranged in the spac~
between pairs of the tamping rools straddling the rails. The
power drive means comprise respective cylinder-piston drives
extending upwardly from the projecting cross beam ends and
linking said ends to the machine frame, the cylinder-piston
drives being spaced outwardly of the ballast tamping unit in
a direction transversely to the operating direc~ion, and the
guide roller means comprises a pair of cylindrical gripping
rollers associated with each one of the track rails, each
track rail having a rail head and the rail head oE the
associated track rail being arranged between a respective one
of the pairs of gripping rollers for being gripped between
the pair of gripping rollers, an inner one of the gripping
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rollers of each one of the pairs of gripping rollers being
rotatably journaled on a ixed vertical axis and an outer one
of ~he gripping rollers of each pair being rotatably
journaled about an axle arranged for pivoting in a vertical
plane extending transversely to the operating direction.
The ballast is compacted by raising the track to a level
above a desired track level, tamping ballast under respecti~e
ones of the ties of the raised track, and simultaneously
imparting essentially hori~ontal vibrations extending
transversely ~o the raised track under whose ties ballast has
been tamped and subjecting the raised track to essentially
vertical load forces until ~he raised track has been lowered
to the desired track level.
This very simple arrangement enables all of the
operating units used in the track surfacing operation to be
so coordinated in time and place that the desired maximum
solidification of the ballast bed and stabilization of the
track position may be assured in a single pass of the mobile
machine while the
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vpera~ing cycle is fully adjusted to the prevailing
conditions and requirements. The selective coordination of
the various operating stages make~ it possible to increase
the effectiveness of the entire operation~ as compared to the
use of separate machines, by permitting the operating units
to interact in efective range and/or phase. For example,
enhanced fluidi~ation of the ballast ~ed over a longer track
section can be o~tained by superimposing the vibratory motion
imparted to the ballast by the tamping tools on the
hori~ontal vibrations generated by the dynamic stabilization,
which reorients the ballast and produces the highest possible
density thereoE. In this manner, dynamic track stabilization
is obtained in the ballast tamping zone itself to take into
account the initial settling of the ballast bed under the
ensuing train traffic. Furthermore, existing track suracing
machines may be used substantially without modification,
except for the track stabilization equipment added thereto,
and conventional and proven track correction and ballast
tamping units may be used unchanged.
The ballast compacting produces a very exact desired
track level long-lastingly fixed in position by a very solid
ballast bed support which settles only insignificantly during
subsequent train traffic, and any such settling oE the
ballast bed proceeds very uniformly because of the homogenous
condition of the ballast. The ballast compacting proceeds
rapidly and dependably, and is well adapted Eor automation o
the various operating steps.
The above and other objects, advantages and features of
the invention will become more apparent from the following
detailed description of certain now preEerred embodiments
thereof, taken in conjunction with the accompanying generally
schematic drawing wherein
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FIG. 1 is a side elevational view of a track tamping,
leveling and lining machine equipped with a track
stabilization unit ln accordance with one embodiment of the
present invention;
FIG. 2 is an enlarged side e:Levation of the ~ombined
ballast tamping and track stabilization unit constituting a
single mechanical structure, as used in the machine of FIG. 1;
FIG. 3 is a partial front view of ~he combinad unit of
FIG. 2r as seen in the direction of arrow III; and
FIG. 4 is a like view of a modiied embodiment of such a
combined unit.
Referring now to the drawing and first to FIGS. 1 to 3,
there is shown mobile machine 1 for compacting ballast of a
ballast bed supporting a track consisting of two rails 4
fastened to ties 5 resting on the ballast. The machine
comprises machine frame 7 and undercarriages 2, 3 supporting
machine frame on the track rails for movement in an operating
direction indicated by arrow 8. Drive 6 powers rear
undercarriage 3 to move the machine in the operating
direction. Power plant 9 for the machine is mounted on the
front end of machine frame 7. Between the power plant and
the rear undercarriage, machine frame 7 carries ballas~
tamping unit 15, track correction unit 10 forwardly of the
tamping unit in the operating direction and track
stabilization unit 17. Preferably, a respective ballast
tamping unit is associated with each rail 4 and, in the
illustra~ed embodiment, each tamping unit includes two pairs
of reciprocable and vibratory tamping tools 36, 37 arranged
-to tamp ballast simultaneously under two respective ties 5
upon immersion of the tamping tools into successive cribs
when vertically
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', ~
movably mounted tamping unit 15 is vertically moved Operator's
cab 21 is mounted on the rear end of machine frame 7 Eor
operating and monitoring the work of units 10, 15 and 17, cab 21
housing control means 22 for automatically and selectively
operating the units. Machine 1 is also equipped with track
correction reference system 23 for controlling track correction
unit 10.
In the illustrated embodiment, track correction unit 10
includes means for liEting and transversely moving the track and
the reference system includes the illustrated system for leveling
the track, machine 1 being a track tamping, leveling and lining
machine. In the illustrated machine, machine frame 7 supports
track correction, ballast tamping and track stabilization units
10~ ]5 and 17 between the two undercarriages 2 and 3. The means
for lifting and transversely moving the track is comprised of
lifting rollers 14 and lining rollers 13 engaging track rails 4,
and lifting jack 12 for raising the track in the direction
indicated by arrows 31. Connecting rod 11 is linked to the
underside of machine frame 7 by a universal joint for attachment
of track correction unit 10 to the machine frame The
illustrated reference system for leveling the track is comprised
of two reference wires 24 respectively associated with rails 4.
The front ends of the reference wires are supported at the front
end of machine frame 7 by a sensing element whose support roller
~5 runs on the rails in a range of the track which has not yet
been leveled and thus indicates the uncorrected level of the
track while the rear ends of the reference wires are supported on
the axle of rear undercarriage 3 to indicate the corrected track
level. If desired, a separate sensing element could also support
the rear end of each reference wire in the leveled track range
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A further track level sensing element 26 is arranged between
track correction unit 10 and ballast tamping unit 15 and the
upper end of sensing element 26 carries track level measuring
sensor 27 which, when contacting reEerence wire 24, emits a
leveling control signal transmitted by line 29 to control means
22 connected to lifting jack 25. Ano-ther track level measuring
sensor 28 is associated with track stabili~ation unit 17 and also
emits a leveling control signal transmitted by line 30 to control
means 22 connected to loading jacks 19, 20 of unit 17. Sensors
27 and 28 have rotary potentiometers carrying a fork-shaped
element receiving the reference wire and adjusted thereby.
Just as the above-described track correction unit and the
reference system associated therewith, the ballast tamping uni~
illustrated herein is conventional and comprises two pairs of
reciprocable tamping tools 36, 37 arranged side-by-side for
immersion into successive cribs for simultaneously tamping two
ties 5. As clearly shown in FIGS. 2 and 31 the tamping unit
comprises tamping tool carrier 35 slidably mounted on vertical
guide columns 34 or vertical movement under the power o drive
16 linking the tamping tool carrier to machine frame 7. A
respective tamping unit is associated with each rail 4 and the
tamping tools are mounted on the tamping tool carrier for pivotal
movement about horizontal fulcrums 38 extending in the operating
direction of the machine to enable the tamping tools to be
reciprocated towards and away from the ties positioned between
the tamping tools of each pair. The upper ends of tamping tools,
3fi, 37 are linked to respective hydraulic reciprocating drives 39
connected in a conventional manner to common, centrally arranged
vibrating drive 41 comprised of a crank shaft driven by a
hydraulic motor. Each tamping tool has two adjacently arranged
tamping jaws 4~ replaceably attached to the lower tool end foe
immersion in the ballast to a depth below the ties. Vertical columns
34 support -the tamping tool carrier in carrier frame 43.
Track stabilization unit 17 is arranged substantially in the
the same area on the machine frame a5 ballast tamping unit 15,
the respective pairs of tamping tools 36, 37 straddling
associated track rail 4 (see FIG. 3~ and the s~raddling pairs oE
tamping tools defining a space therebetween wherethrough the
associated track rail extends. Connecting rod 18 links unit 17
to the machine frame ~or movement with the machina in the
operating direction.
The illustrated track stabilization unit has a chassis
including an elongated carrier 44 associated with each track rail
4 and arranged in the space between the straddling pairs of
tamping tools 36, 371 and cross beams 45 rigidly interconnecting
the elongated carriers. The cross beams are equipped with
'tF h C~ 4 h-~ a ~
~;~, vibrator means ~6 for imparting essentially hori~intal vibrations
to the track in the direction indicated by double-headed arrow 47
whereby the elongated carriers are rigidly connected with the
vibrator means. Guide rollers means 48, 49 are mounted on the
elongated carriers for firmly holding the chassis ~f the track
stabilization unit in engagement with the track rails and for
guiding the chassis along the track upon movement of machine
frame 7 in the operating direction indicated by arrow 8. The
illustrated guide roller means comprises two flanged wheels 48
guiding the chassis along each track rail without play in a
vertical and horizontal direction and, arranged therebetween, two
gripping rollers 49 ro~atably journaled in casings 50 for pivotal
movement into and out of gripping engagement with the outside of
the associated track rail. Each gripping roller is mounted on a
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respective elongated carrier in a range extending betwen tamping
tools 36, 37 oE the pairs of tamping tools (see FIG. 2) whereby
the pairs of tamping tools straddle the gripping rollers. The
gripping rollers clamp the track therebetween when the gripping
rollers are in gripping engagement with the outsides of the track
rails under the power of drive 5~ for pivot ng each gripping
roller about axis 51 extending in the operating direction. Drive
52 is a cylinder-piston drive linking casing 50 of gripping
roller 49 to cross beam 45 and is capable of moving the gripping
roller into subtending engagement with the rail head of each
track rail. With the rail heads firmly clamped between flanged
wheels 48 on the inside and gripping rollers 49 on the outside,
the vibratory motion indicated by arrow 47 will be directly
transmitted to the track rails and ties 5 to which they are
fastened, thus setting the surrounding ballast into vibratory
motion.
Finally, power drive means l9, 20 connect the chassis of the
track stabilization unit to machine frame 7 and this power drive
means is arranged to impart essentially vertical load forces to
the chassis. The illustrated power drive means comprises
respective cylinder-piston drives linking the ends oE each
elongated carrier 44 to machine frame 7 (see FIG. 2). Drives 19,
20 extend substantially in a vertical plane defined by associated
track rail 4 and tamping unit 15 is arranged between the ends of
the elongated carriers. In this manner, loading drives 19, 20
will subject the track to the vertical load forces centrally
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within the vertical plane defined by the ~ ci~tc~ track rail.
The above-described embodiment uses the space available on
the machine frame in the operating direction of the machine in a
very economical manner and thus enables the length of the machine
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frame to he helcl down, making it possible to e~uip existing traclc
surfacing machines wi-th a track stabilization unit without
substantial structural changes. Furthermore, considerable
operating advantages are obtained by superimposing the effective
ranges of the ~amping and dynamic ~rack stabilization zones.
Thus, the entire operating zone is readily observable by a single
operator and it is also possible to superimpose the horizontal
vibrations on the tamping vibrations imparted to the ballast by
the tamping tools~ In this manner, the ballast is compacted
during the tamping operation not only underneath the ties but
also in the cribs as well as along the shoulders at the tie ends~
The described arrangement of the power drive means for the
track stabilization unit makes it possible not only to subject
the elongated carriers o~ the stabilization unit chassis to
considerable vertical load forces but also to subject the
respective ends of the elongated carriers to different load
forces. This enables the compaction of the ballast and the
corresponding lowering of the track level to be fine-tuned to an
unusual extent by subjecting the track to a larger downward
pressure at the front end of the track stabilization unit whereby
the track level is lowered there farther than at the rear end
where a smaller downward pressure is used to position the track
accurately at the desired track level at the very end of the
surfacing operation.
The described and illustrated arrangement of gripping
rollers 49 makes good use of the available space between the
pairs of tamping tools and enables the rollers to be outwardly
pivoted. In this space, the gripping rollers are readily
accessible and their positioning therein has the added advantage
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that they are positioned in the tamping æone in vertical
alignment with each tie being tampe~ whereby the horizontal
vibrations are directly transmitted to ties 5 by the fastening
elements fixing the rails to the ties.
In the modified embodiment shown in ~IG. 4, a single tie
tampin~ unit 53 is combined with track stabilization unit 54 and
this embodiment differs from that hereinabove described in the
following manner:
Cross beams 56 rigidly interconnect elongated carriers 57
and are equipped with vibrator means 55 but these cross beams
have ends 58 projecting beyond the elongated carriers.
CYlinder-piston drives 59 extend upwardly from projecting cross
beam ends 58 and link the ends to machine frame 61) laterally
extending brackets 60 supporting the upper ends of drives 59
which are spaced outwardly of ballast tamping unit 53 in a
direction transverse to the operation direction of the machine.
The guide roller means of this modified embodiment comprises a
pair of cylindrical gripping rollers 62, 63 associated with each
rail 68 and each track rail has a rail head arranged between a
respective pair of the gripping rollers Eor being gripped between
the pair of gripping rollers, Inner gripping roller 62 of each
~ ata~
pair of gripping rollers is rot-t~lc journaled on a fixed
vertical axis 64 on the cross beam and outer gripping roller 63
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each each pair is rotat~blc journaled about an axle 65 arranged
on the cross beam for pivoting in a vertical plane extending
transversely to the operating direction of the machine. Jack 66
links the pivotal axle to the cross beam for effectuating the
pivoting of gripping roller 63. The guide roller means also
includes flanged wheels 67 operating in the manner of wheels 48
in the first-described embodiment. Two, four or even more such
flanged wheels may be mounted on each elongated carrier 57 oE
the track stabilization unit chassis for suitable guidance o~
the unit along the track.
This modified embodiment has the particular advantage
that the horizontal vibrations as well as the vertical load
forces are transmitted to each track rail in the central area
of the track stabilization unit directly and, therefore, to
their ~ull extent. This embodiment is particularly useful in
combination with ballast tamping units designed Eor tamping a
single tie at a time, the cross beam extending between the
tamping tools of the pair of tamping tools straddling the tie
to be tamped whereby much space is saved while the operating
elements of the tamping and track stabilization units remain
readily accessible.
According to the invention, the above-described mobile
machines are operated in the following manner to compact
ballast of a ballast bed supporting a track whose position
has been corrected:
The machine is advanced to a tamping station and the
track is raised to a level above a desired track level, at
which time the vibrator means of the track stabilization unit
may or may not be operated. The ballast: is tamped under the
tie or ties at the tamping station by operating the pairs of
reciprocable and vibratory tamping tools arranged to tamp
ballast under the ties upon immersion of the tamping tools in
the ballast when the tamping unit is veltically moved and, if
the vibrator means of the track stabilization unit has not
been previously activated, it is operated at the same time as
the tamping tools for simultaneously imparting essentially
horizontal vibrations extending transversely to the raised
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track under whose ~ies ballast has been tamped and ~he raised
track is subjected to essentially vertical load forces until
the raised track has been lowered ~o the desired track
level. Due to the effect of the horiæontal vibrations and
vertical load forces simultaneously imparted to the raised
track, the track ties axe rubbed into the tamped ballast and,
since the ballast is fluidized under these transverse and
vertical vibratory forces to be reoriented and to flow into
an ever denser compaction, the resultant decreased volume of
the ballast causes a lowering of the ballast bed level until
the track has reached the desired level. The rear
undercarriage of the mobile machine transmits the heavy
machine load to the track which has been stabilized and
prevents the vibrations of the track stabilization uni~ to be
extended therebeyond to the previously corrected and
stabilized track section behind the rear undercarriage. As
this heavy vertical load is transmitted to the track and
underlying ballast bed by -the rear undercarriage of the
moving machine, it further serves to solidify the stabilized
track. The track level sensors cooperating with the
reference system monitor and control the operations of the
track correction, ballast tamping and track stabilization
units to assure that the desired track position is obtained.
The essentially horizontal vibrations are imparted to
the raised track solely during a time period encompassing the
tamping and lowering of the track to the desired track
level. This avoids any influence of the track stabilization
operation on the track correction operation, and the combined
effect of the tamping tool and stabilization unit vibrations
produces a very intense ballast flow which greatly enhances
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the degree of ballast comp~ctlon in the en~ire opera~ing zone.
Particularly in track sections requiring no or only
small lifts to obtain a desired track level, the track may be
raised to the level above the desired track level sol~ly by
upward pressure of the tamped ballast and without the use oE
the track correction unit, and the raised t~ack is held at
this level while tamping is continued~ The essentially
hori%ontal vibrations are imparted to the track and the track
is subjected to the vertical load forces thereafter until the
track has been lowered to the desired track level. This
assures that the track is not unduly raised under the tamping
pressure and limits the track lift to an extent which does
not exceed the subsequent lowering of the track to the
desired level. Furthermore, the ballast may be compacted
under the ties more densely simply by increasing the
reciproca~ing power of the tamping tools.
Preferably, after the track has been lowered to the
desired track level, it is subjected to a static vertical
load exerted by the rear undercarriage of the moving machine
in the operating direction. In this manner, the amplitude of
the horizontal vibrations imparted to the ~rack is gradually
reduced until the vibrations are entirely halted by the
static downward pressure on the track by the rear
undercarriage.
It will be obvious to those skilled in the art that many
structural modifications may be introduced into the track
correction, ballast tamping and track stahili~ation units
described and illustrated herein by way of example without
departing from the spirit and scope of the present invention
as defined in the appended claims. For example, the track
stabili~ation unit may be arranged in the range of the
tamping units but transversely staggered in relation thereto
so that the tamping and stabillzation may be properly
coordinated in their effect on the ballast compaction. The
reference system also may be varied in any desired manner.
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