U.S. patent number 3,926,123 [Application Number 05/404,427] was granted by the patent office on 1975-12-16 for track surfacing apparatus.
Invention is credited to Franz Plasser, deceased, by Erna Plasser, heir, Klaus Riessberger, Egon Schubert, Josef Theurer.
United States Patent |
3,926,123 |
Plasser, deceased , et
al. |
December 16, 1975 |
Track surfacing apparatus
Abstract
Ballast is compacted and the track is leveled simultaneously by
imparting a substantially horizontal vibration to the track while
pressing the track substantially vertically down to the desired
level.
Inventors: |
Plasser, deceased; Franz (LATE
OF Vienna, OE), Plasser, heir; by Erna (Vienna,
OE), Theurer; Josef (Vienna, OE), Schubert;
Egon (Vienna, OE), Riessberger; Klaus (Vienna,
OE) |
Family
ID: |
3608770 |
Appl.
No.: |
05/404,427 |
Filed: |
October 9, 1973 |
Foreign Application Priority Data
|
|
|
|
|
Oct 13, 1972 [OE] |
|
|
8816/72 |
|
Current U.S.
Class: |
104/7.1; 104/12;
104/8 |
Current CPC
Class: |
E01B
29/04 (20130101); E01B 27/13 (20130101) |
Current International
Class: |
E01B
27/00 (20060101); E01B 27/13 (20060101); E01B
29/00 (20060101); E01B 29/04 (20060101); E01B
037/00 () |
Field of
Search: |
;104/7,8,7B,12 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: King; Lloyd L.
Assistant Examiner: Bertsch; Richard A.
Attorney, Agent or Firm: Kelman; Kurt
Claims
What we claim is:
1. An apparatus for surfacing a track consisting of rails fastened
to ties resting on ballast, comprising means for determining any
deviation of the track position from a desired level, means for
imparting a substantially horizontal vibration to the track
including a vibration-producing means and means for transmitting
the vibration produced by said means to the track, and means
arranged in association with the vibration imparting means for
imparting a substantially vertical downward ballast compacting
pressure on both rails of the track whereby the ballast under the
track ties may be compacted simultaneously with positioning the
track at the desired level.
2. The track surfacing apparatus of claim 1, further comprising an
apparatus frame and an auxiliary car vertically adjustably mounted
on the apparatus frame, the auxiliary car carrying the vibration
and pressure imparting means.
3. The track surfacing apparatus of claim 1, wherein the means for
imparting the downward pressure on the rails comprises hydraulic
rams supported on the apparatus.
4. The track surfacing apparatus of claim 1, further comprising
ballast tamping and track lifting means mounted ahead of the
vibration and pressure imparting means in the working direction of
the apparatus.
5. The track surfacing apparatus of claim 2, wherein the means for
transmitting the vibration comprises double-flanged wheels engaging
the track rails and imparting the vibration to the track rails.
6. An apparatus for surfacing a track consisting of rails fastened
to ties resting on ballast, comprising means for determining any
deviation of the track position from a desired level, means for
imparting a substantially horizontal vibration to the track
including a vibration-producing means and a pair of pressure plates
vertically adjustably arranged for pressure engagement with the end
of respective ones of the ties for transmitting the vibration
produced by the vibration-producing means to the track, means for
varying the distance between the pressure plates in the direction
of elongation of the ties to effectuate said pressure engagement,
and means arranged in association with the vibration imparting
means for imparting a substantially vertical downward ballast
compacting pressure on both rails of the track whereby the ballast
under the track ties may be compacted simultaneously with
positioning the track at the desired level.
7. The track surfacing apparatus of claim 6, wherein the distance
varying means includes a pair of guide levers carrying the pressure
plates, the guide levers being operatively coupled to the
vibration-producing means.
8. An apparatus for surfacing a track consisting of rails fastened
to ties resting on ballast, comprising means for determining any
deviation of the track position from a desired level, means for
imparting a substantially horizontal vibration to the track
including a vibration-producing means and a pair of double-beveled
rotatable wheels each defining a substantially V-shaped peripheral
groove receiving the rail heads of the respective rails for
transmitting the vibration produced by the vibration-producing
means to the track rails, and means arranged in association with
the vibration imparting means for imparting a substantially
vertical downward ballast compacting pressure on both rails of the
track whereby the ballast under the track ties may be compacted
simultaneously with positioning the track at the desired level.
9. The track surfacing apparatus of claim 8, wherein the groove has
an outer portion wider than the width of the rail head received
therein.
10. The track surfacing appartus of claim 8, further comprising two
parallel transverse axles spaced from each other and laterally
movable in respect of the track, the rotatable wheels being fixedly
mounted on opposite ends of the adjacent axles for gripping a
respective one of the rail heads in their peripheral grooves, and
smooth rollers running on top of the rail heads carried by the
other axle ends.
11. The track surfacing apparatus of claim 8, further comprising a
transverse axle for mounting the rotatable wheels at respective
ends thereof, one of the wheels being mounted against transverse
movement in relation to the axle, the other wheel being mounted for
transverse movement in relation to the axle, and means for moving
the other wheel to vary the distance between the wheels for
adaptation to varying track gages.
12. The track surfacing apparatus of claim 11, further comprising
means for stopping the other wheel in a selected lateral
position.
13. The track surfacing apparatus of claim 8, further comprising a
pair of guide levers carrying the rotatable wheels, and means for
pivoting the guide levers in a plane transverse to the track about
fulcrum axes extending substantially parallel to the track to vary
the distance between the rotatable wheels.
14. The track surfacing apparatus of claim 13, further comprising a
rigid carrier interconnecting the fulcrums of the guide levers
intermediate their ends, the vibration-producing means being
carried by the carrier, the rotatable wheels being mounted at one
end of the guide levers, and the pivoting means being linked to the
other ends of the guide levers.
15. An apparatus for surfacing a track consisting of rails fastened
to ties resting on ballast, comprising means for determining any
deviation of the track position from a desired level, means for
imparting a substantially horizontal vibration to the track
including a vibration-producing means and means for transmitting
the vibration produced by said means to the track, hydraulic rams
supported on the apparatus in association with the vibration
imparting means for imparting a substantially vertical downward
ballast compacting pressure on both rails of the track whereby the
ballast under the track ties may be compacted simultaneously with
positioning the track at the desired level, and a
vibration-producing means associated with respective ones of the
hydraulic rams, the latter means being arranged to produce
vibrations substantially parallel to the ram pressure.
16. The track surfacing apparatus of claim 15, further comprising a
spring means mounted between the vibration-producing means and the
apparatus whereon the ram is supported.
17. An apparatus for surfacing a track consisting of rails fastened
to ties resting on ballast, comprising means for determining any
deviation of the track position from a desired level, means for
imparting a substantially horizontal vibration to the track
including a vibration-producing means and means for transmitting
the vibration produced by said means to the track, rail engaging
wheels and hydraulic rams mounted in vertical alignment with the
wheels on the apparatus in association with the vibration imparting
means for imparting a substantially vertical downward ballast
compacting pressure on both rails of the track whereby the ballast
under the track ties may be compacted simultaneously with
positioning the track at the desired level.
18. An apparatus for surfacing a track consisting of rails fastened
to ties resting on ballast, comprising means for determining any
deviation of the track position from a desired level, means for
imparting a substantially horizontal vibration to the track
including a vibration-producing means and means for transmitting
the vibration produced by said means to the track, and a plurality
of hydraulic rams supported on the apparatus and spaced from each
other in the direction of track elongation in association with the
vibration imparting means for imparting a substantially vertical
downward ballast compacting pressure on both rails of the track
whereby the ballast under the track ties may be compacted
simultaneously with positioning the track at the desired level.
19. An apparatus for surfacing a track consisting of rails fastened
to ties resting on ballast, comprising means for determining any
deviation of the track position from a desired level, means for
imparting a substantially horizontal vibration to the track, an
apparatus frame, and an auxiliary car vertically adjustably mounted
on the apparatus frame, means carried by the auxiliary car and
arranged in association with the vibration imparting means for
imparting a substantially vertical downward ballast compacting
pressure on both rails of the track whereby ballast under the track
ties may be compacted simultaneously with positioning the track at
the desired level, said pressure imparting means including rail
engaging wheels mounting the auxiliary car for movement along the
track and hydraulic rams in vertical alignment with the wheels to
exert the pressure on the track by means of the wheels, one end of
the rams being supported on the apparatus frame while the other
ends thereof are supported on the auxiliary car.
20. The track surfacing apparatus of claim 19, further comprising
elongated rods coupling the auxiliary car to the apparatus frame,
the respective arm ends being pivotally supported on the apparatus
frame and the auxiliary car.
21. An apparatus for surfacing a track consisting of rails fastened
to ties resting on ballast, comprising means for determining any
deviation of the track position from a desired level including
means for producing an error signal proportional to the determined
deviation, means for imparting a substantially horizontal vibration
to the track, means arranged in association with the vibration
imparting means for imparting a substantially vertical downward
ballast compacting pressure on both rails of the track whereby the
ballast under th track ties may be compacted simultaneously with
positioning the track at the desired level, and further comprising
electrical control circuit means responsive to the error signal for
actuating the vibration and downward pressure imparting means.
22. The track surfacing apparatus of claim 21, wherein the means
for determining the track position deviations is mounted adjacent
the pressure imparting means.
23. The track surfacing apparatus of claim 21, wherein the
electrical control circuit means is arranged to control pressure
imparting means associated with each rail separately.
24. The track surfacing apparatus of claim 21, wherein the means
for determining the track position deviations includes a
potentiometer adjustable in response to the deviations to produce
the proportional error signals, and the electrical control circuit
means includes a bridge circuit comprising the potemtiometer and
having an output, and a circuit element receiving the error signals
from the bridge circuit output, comparing the error signal with a
reference signal proportional to the desired track level, and
producing an amplified control signal resulting from the comparison
for actuating the vibration and downward pressure imparting
means.
25. The track surfacing apparatus of 24, wherein the pressure
imparting means comprises hydraulic ram means, a hydraulic fluid
circuit delivering hydraulic fluid to the ram means, and a solenoid
pressure control valve in the fluid circuit, the valve being
arranged in the control circuit means for actuation by the control
signal.
26. The track surfacing apparatus of claim 24, wherein the
vibration imparting means comprises vibration-producing means and
hydraulic drive motor means for actuating the vibration-producing
means, and further comprising a hydraulic fluid circuit delivering
hydraulic fluid to the drive motor means, and a solenoid valve
controlling the fluid throughput of the hydraulic circuit, the
valve being arranged in the control circuit means for actuation by
the control signal.
27. The track surfacing apparatus of claim 24, wherein the
vibration imparting means comprises a vibration-producing means and
an electric drive motor means for actuating the vibration-producing
means, and further comprising an electric circuit operating the
drive motor means, the electric circuit being energized by the
control signal.
28. The track surfacing apparatus of claim 27, wherein the
vibration and downward pressure imparting means includes a
plurality of vibration-producing means and a plurality of pressure
means, the electrical control circuit means being arranged to
transmit the control signal in stages to selected ones of said
vibration-producing and pressure means.
29. The track surfacing apparatus of claim 21, wherein the means
for determining the track position deviations includes an element
vertically moving with the track according to its level, a camming
surface fixedly mounted on the element, and switch means in the
electrical control circuit means arranged for sequential actuation
by the camming surface in response to vertical track movement for
transmitting the error signal to the selected vibration-producing
and pressure means.
Description
The present invention relates to improvements in apparatus for
surfacing a track consisting of rails fastened to ties resting on
ballast.
In track surfacing, it has been proposed to impart at least
substantially horizontal vibration to a track in a section wherein
the ballast is compacted, particularly under the track ties and
while the track is positioned at a desired level. In the leveled
track, the ballast serves to absorb the forces to which passing
trains subject the track. In view of the resiliency and wear of the
ballast, the track level changes in the course of time. Therefore,
the track must be leveled from time to time to achieve the desired
grade, at which the track is fixed by tamping the supporting
ballast under the ties.
Tie tamping forms an essential part of many known track leveling
methods. In this operation, the ballast is compacted underneath the
ties by pressure and vibration to the highest attainable degree to
form as rigid a track support as possible. However, none of the
known tamping methods has succeeded in fixing the track at a
desired level sufficiently to resist depression by passing trains
for long. Immediately after tamping, the track settles rather
rapidly and this downward movement slows down with time. This
phenomenon results from the fact that the tamping relocates the
ballast pieces in new positions in which they are subjected to the
vertical, static and dynamic loads of passing trains, leading to
their wear and settling. Since the ballast does not settle
uniformaly along the track, many deviations from a straight level
soon appear.
An attempt has been made to improve the ballast compaction by
subjecting the ballast to vertical vibrations transmitted to the
ballast by the track rails and/or ties, or directly by vibratory
surface compactors. However, it has not been possible in commercial
operations to obtain a permanently fixed ballast bed in this
manner. Similar lack of success has been encountered with vibrating
the track solely in a horizontal direction.
In another known track correction method, the track section to be
corrected is subjected to vibrations and is raised to the desired
level. Subsequently, the ballast is tamped under the ties to fix
the track at the raised level. This method has not been
commercially used.
It is a primary object of this invention to provide track surfacing
which results in a durable and more uniformly compact ballast
support for the track ties. The track surfacing of the invention
"discounts" the usual settling of the newly tamped ballast under
the loads of trains passing thereover.
The above and other objects are accomplished according to the
invention by imparting a substantially horizontal vibration to the
track while pressing the track substantially vertically down to the
desired level to compact the ballast under the track ties and
simultaneously position the track at a desired level. Any deviation
of the track position from a desired level may be determined and
the track pressed to the desired lower level.
Unexpectedly, the combination of the horizontal vibration and the
downward pressure provides a ballast compaction which far surpasses
the quality achieved with known track surfacing methods and
equipment. During the ballast compaction according to the present
invention, the ties are pressed into the ballast and this vertical
downward movement of the track into the compacted ballast is taken
into account in determining the desired track level. In this way,
the track surfacing actually simulates and discounts the subsequent
train traffic so that the desired level will be maintained despite
of it.
Since long used track usually has been pressed by the passing train
traffic below the desired grade, it will be useful in such cases to
raise the track above this level and to tamp the ballast under the
ties of the raised track before track surfacing is effected in
accordance with the invention. When a newly laid track section is
installed, this will not be necessary since such track is laid at a
higher than desired grade and may then be directly leveled to the
desired grade by means of the track surfacing of the present
invention.
Throughout the specification and claims, the term "substantially
horizontal vibration" means a vibration with a marked horizontal
component extending transversely of the track elongation. Thus, the
vibration may be produced in planes oblique to the horizontal plane
as long as the resultant vibration has a marked horizontal
component.
Preferably, the vibration has the same or nearly the same frequency
as the natural or characteristic frequency of vibrations of the
track, measured in a transverse direction, the frequency being, for
instance, in the range of 8 to 13 cycles per second. This has the
advantage that the vibrating force may be relatively small since
the vibrated track section will be in resonance.
The track surfacing of this invention is very flexible and
sensitive because it opens the way to a variety of controls. Thus,
it is of particular advantage to determine the downward stroke
required to press the track down to the desired level, i.e. the
deviation of the track therefrom, to produce an error signal
proportional to the deviation, and to control the frequency and/or
the amplitude and/or the duration of the vibration and/or the force
and/or the duration of the downward pressure in response to the
error signal.
Controlling the force of the downward pressure on the track in
response to the error signal has the best results, i.e. the track
responds best to changes in the force of the pressure as far as
track leveling is concerned. However, changing the vibration
frequency and/or amplitude also has advantages. Combining and/or
selecting the indicated controls enables the operator to adapt the
operation to ballast beds of all types.
It is particularly useful to select the downward pressure force so
that it corresponds to the order of magnitude of the train loads
expected in traffic over the surfaced track section. However, since
this would require very heavy surfacing equipment, it is
advantageous to press the track down by a pulsating stress force.
Such a stress may be a dynamic force and is, therefore, independent
of the weight of the machine. In a preferred embodiment, the
pressure force has a static and dynamic component, the dynamic
component being an oscillating force whose amplitude does not
exceed twice the static component of the pressure force. In this
way, the pulsating stress will press on the track without lifting
the apparatus off the track.
It is possible to effectuate track surfacing according to the
invention stepwise or continuously as the apparatus advances along
the track. In the latter case, it is useful to determine any
deviation of the track position from the desired level continuously
while imparting the horizontal vibration and downward pressure to
the track. This may be done, for instance, with the track
correction apparatus described and claimed in U.S. Pat. Nos.
3,211,109 or 3,042,982. Since the above-described controls make it
possible to position the track at the desired level relatively
rapidly in accordance with the invention, the continuous method
produces a very high efficiency.
The determinative opertional parameters, such as pressure force,
frequency and amplitude of vibration, and duration, may be
controlled not only in response to an original error signal but
also by a continuous error signal during the movement of the track
to the desired level. Thus, it may be useful to increase the
pressure force as the track approaches the desired grade since the
compaction of the ballast increases correspondingly so that the
ballast yields less and less to the downward pressure. In this way,
the duration of the downward pressure may be decreased and the
efficiency of the operation proportionally increased.
Also, the amplitude of vibration may be considerably reduced or the
vibration may be totally stopped shortly before the track reaches
the desired level so that the ballast pieces will not be unduly
dislocated by vibrations at this level.
Since the downward pressure lodges the track ties within the
ballast, the track surfacing according to the present invention
also tends to fix the track strongly in its lateral position.
Therefore, it will be most useful to line the track ahead of the
track surfacing or in the range thereof.
In the apparatus according to this invention, the arrangement and
type of means for imparting a substantially vertical downward
pressure on both rails of the track are of particular importance.
The preferred pressure means are hydraulic rams and, to make a
continuous operation possible, the rams are supported on a mobile
apparatus and preferably are mounted in vertical alignment with
rail engaging wheels to exert the pressure on the track by means of
the wheels. Thus, with the proper pressure control for the rams,
the pressure force may reach the magnitude of the weight of the
apparatus.
To obtain different pressures along the track section in the
surfacing zone, a plurality of hydraulic rams may be spaced in the
direction of track elongation and may be subjected to different
pressures. In this manner, no special controls are needed to obtain
a stepped change in the pressure force exerted upon the same track
point as the apparatus advances continuously along the track. It is
also useful to arrange a plurality of pressure means in a direction
transverse to the track since different pressures applied to such
means can take into account any superelevation of the track or
different track level errors at the two rails at the same track
point.
Similarly, a plurality of vibration imparting means may be spaced
in the direction of track elongation so that the vibration
amplitude may be changed simply by switching on or off additional
vibrators.
The above and other objects, advantages and features of the present
invention will become more apparent from the following detailed
description of certain now preferred embodiments thereof, taken in
conjunction with the accompanying drawing wherein
FIG. 1 is a schematic side elevational view of an apparatus
incorporating structures arranged and designed to carry out the
method of this invention;
FIG. 2 is a like view of such an apparatus incorporating modified
structures of the indicated type;
FIGS. 3 and 4 are schematic transverse sections of the apparatus of
FIG. 2 along lines III--III and IV--IV, respectively;
FIGS. 5 and 6 are side elevational and top plan views,
respectively, of an embodiment of an auxiliary car carrying the
pressure-applying and vibrator structures used in the
invention;
FIGS. 7 and 8 are transverse sections of the auxiliary car along
lines VII--VII and VIII--VIII, respectively, of FIG. 6;
FIGS. 9 to 13 schematically illustrate various embodiments of
structures for transmitting horizontal vibrations from the
vibrations to the track;
FIG. 14 schematically illustrates an embodiment of a structure for
transmitting horizontal vibrations directly to the track ties;
FIG. 15 is a circuit diagram of a control circuit for controlling
the downwardly applied pressure in dependence on, or a function of,
the position of the track;
FIGS. 16 and 17 are circuit diagrams of control circuits for
controlling the frequency of the vibrations in dependence on, or a
function of, the position of the track;
FIGS. 18 and 19 are circuit diagrams of control circuits for
controlling the amplitude of the vibrations in dependence on, or a
function of, the position of the track;
FIG. 20 is a circuit diagram of a control circuit for
simultaneously controlling the downwardly applied pressure and the
amplitude of the vibrations in dependence on, or a function of, the
position of the track; and
FIG. 21 schematically shows an embodiment of the invention in
combination with a track leveling and tamping machine, in side
elevation.
Referring now to the drawing, wherein like reference numerals
designate like parts operating in a like manner in all figures,
FIG. 1 shows a mobile apparatus with a machine frame 1 mounted on
wheels 2 running on rails 6 which, together with ties to which the
rails are affixed, form the track. Track sensing elements 3 and 4
are vertically movably mounted in frame 1 at its front and rear
ends, respectively, the lower ends of the track sensing elements
engaging the track while their upper ends carry a reference line,
for instance a tensioned wire 5. In the illustrated embodiment, the
track sensing elements are bogies whose wheels run on the track
rails and which carry poles on whose tops rollers are mounted over
which the tensioned wires 5 are trained. As is well known,
reference wires 5 serve as a reference for determining the desired
track level.
A measuring device 7 is mounted on frame 1 to measure the vertical
distance between each rail 6 and its associated reference wire 5.
For this purpose, the upper end of measuring device 7 carries a
sensor for sensing the level of reference wire 5. This sensor may
be, for instance, a wire engaging element, such as a fork or a
roller, connected with a potentiometer. The potentiometer is
adjusted mechanically by the reference wire or by servomechanical
means whenever there is a change in the distance between a rail and
its associated reference wire. The amount of adjustment of the
potentiometer is a measure of the change of distance, as is more
fully described in U.S. Pat. No. 3,547,039, dated Dec. 15,
1970.
The lower end of measuring device 7 is affixed to pressure roll 8
which is pressed against the associated rail 6, for instance by
hydraulic ram 9 which exerts a vertically downward pressure on the
roll. In this manner, the pressure roll follows the rail and
transmits any changes in the distance between the rail and the
associated reference wire, due to a faulty track level, to the
measuring device to actuate the potentiometer in the indicated
manner.
Double-beveled or flanged wheels 11 are mounted on the machine
frame to grip associated rail 6 (see FIGS. 9 to 13) and to hold
each rail for substantially horizontal movement therewith, wheels
11 being arranged in pairs, with one wheel in front and the other
wheel in back of pressure roll 8, preferably equidistant therefrom.
A hydraulic motor 10 is associated with each wheel 11 to apply a
downward pressure thereagainst to maintain the engagement between
the wheels and their associated rails. A vibrator means (not shown)
is associated with wheels 11 and arranged to impart vibrations or
oscillations in a substantially horizontal direction transverse of
the track to the wheels. Since hydraulic motors 10 assure gripping
engagement of wheels 11 with rails 6, the substantially horizontal
vibrations or oscillations are imparted to the track, i.e. the two
rails affixed to the ties. Preferably, the vibrations imparted to
the track will have the same or about the same frequency as the
natural or characteristic frequency of vibrations of the track, for
instance 8 to 13 cycles per second.
Mounted immediately behind the rear vibratory wheels 11 is a track
lining unit 12 of generally conventional type and, therefore,
illustrated only schematically. Such a unit includes track gripping
rollers connected to a hydraulic motor for shifting the rollers
laterally for lining the track.
The use of double-beveled wheels defining a substantially V-shaped
peripheral groove engaging the rails enables the wheels to be used
with rail heads of different widths and this assures constant
gripping of the track rails during the continuous advance of the
apparatus over a long stretch of track. Since the tail-gripping
wheels are pressed down against the rails, the horizontal
vibrations cannot cause disengagement of the wheels from the
rails.
In essence, the apparatus of FIG. 2 has the same structure as that
of FIG. 1 described hereinabove. Swivel trucks 2', 2' mounted
machine frame 1 for mobility on the track rails, a pair of front
and rear sensing elements 3 and 4 carrying the reference wire 5 for
determining the level of the track.
In this embodiment, a vertically adjustable auxiliary car 13 is
arranged underneath machine frame 1 and is attached thereto by
coupling rod 30. The auxiliary car runs on wheels 14, 14 on the
track rails. A pair of hydraulic rams 15, 15 are mounted between
frame 1 and frame 16 of the auxiliary car vertically aligned with a
respective pair of wheels 14, 14 so that the wheels are pressed
vertically downwardly against the track rails. In this manner, the
car wheels 14, 14 operate in the same way as pressure rolls 8 to
exert a downward pressure on the track. A pair of double-beveled or
flanged wheels 17 are journaled on axle 18 intermediate the
pressure wheels 14, 14, preferably equidistant therefrom, the axle
being mounted on car frame 16 (see FIG. 4). Vibrator means 19, such
as rotating unbalanced weights, are mounted on axle 18, the main
component of the vibrations caused by this means extending in a
substantially horizontal plane. These vibrations are transmitted
from the axle by wheels 17 to the track.
As shown in FIGS. 2 and 3, auxiliary car 13 carries a measuring
device 7 associated with each wheel 14 for measuring the distance
between the track and the reference line 5 at each wheel. In this
manner and as will be explained hereinbelow, the downward pressure
exerted upon the track by hydraulic motors 15 through wheels 14 may
be controlled at different track points in dependence on the
position of the track at these points.
In this embodiment, too, a track lining unit 12 is mounted on frame
1 behind the arrangement for exerting a downward pressure and a
horizontal vibration upon the track.
FIGS. 5 to 8 show a specific embodiment of an auxiliary car, such
as used in the embodiment of FIG. 2. The car comprises essentially
a frame 16 of rectangular or quadratic shape which carries a pair
of axles 20 on whose ends wheels or pressure rolls 14 are
journaled. Pivots 21 are mounted on car frame 16 vertically above
axles 20, 20, the outer ends of the piston rods of hydraulic rams
15, 15 being affixed to the pivots while the opposite ends of the
hydraulic ram cylinders are affixed to pivots 22 which are mounted
on machine frame 1, each axle 20 and pivots 21, 22 lying in a
vertical plane extending transversely of the track. Hydraulic rams
15 not only exert a downward pressure on wheels 14 of the auxiliary
car but also serve for the vertical adjustment of the car.
A pair of symmetrically arranged transverse braces 23, 23 reinforce
and sub-divide car frame 16. A box-shaped carrier 24 is mounted on
the frame between the transverse braces by means of parallel links
25, 25 which enable the carrier to be vertically reciprocated in
relation to frame 16. A pair of unbalanced rotating weights 26, 26
is mounted on the carrier symmetrically in respect of the
longitudinal axis of the track on each side thereof, the weights of
each pair rotating in opposite directions, as indicated by the
arrows in FIG. 8.
Bearing boxes 27 are mounted on each end of the carrier 24 and
double-beveled wheels 28 are journaled in the bearing boxes. Fluid
pressure motors 29 are linked between the carrier and machine frame
1 to exert downward pressure on wheels 28 as well as to enable the
carrier to be vertically reciprocated by swinging links 25, 25 up
and down. The links 25 are sufficiently resilient in a transverse
direction to permit carrier 24 to be swung slightly in a direction
transverse to the track so that its horizontal vibratory forces are
kept from auxiliary car frame 16.
Coupling rods 30 connect the auxiliary car to machine frame 1 to
prevent the car from moving in forwardly or backwardly in the
direction of track elongation when the hydraulic rams 15 exert a
downward pressure on the track.
Each measuring device 7 includes a vertical pole 31 pivoted to the
car frame 16 and moving vertically with it in response to the track
position at the track point engaged by a respective wheel 14.
Since it is the purpose of the present invention to fix the track
at a desired level by subjecting it to horizontal vibrations and
pressing it downwardly to the desired level, the arrangement of the
means for transmitting the downward pressure and the vibrations to
the track and thus to the ballast therebeneath is of special
importance. In this respect, the mounting of these means on an
auxiliary car, as shown in FIGS. 2 to 8, is particularly useful
because this enables the vibrations to be kept away from the main
frame of the mobile apparatus and any sensitive measuring
instruments mounted thereon. In addition, the auxiliary car, being
relatively small and light, can better follow the track and thus
increases the accuracy of the measurements of the distance between
the track and the reference line, which determine the accuracy of
the leveling operation.
It is particularly useful to superimpose a dynamic component upon a
static component of the downward pressure force so that the track
is subjected to a pulsating stress in a vertical direction. This is
accomplished most advantageously in the manner illustrated in FIG.
7 wherein a vibrator 33 constituted by a rotating unbalanced weight
is mounted in the line of the downward pressure force exerted by
hydraulic ram 15. In this manner, the dynamic force of vibrator 33
is arithmetically added to the pressure force of motor 15 without
uncontrollable lateral movements or vibrations.
As shown in FIG. 7, the lower end of hydraulic ram 15 is supported
by a spring means 32, for instance a cup spring, on vibrator 33
which is mounted directly on frame 16 of the auxiliary car. The
interposition of the spring means has the advantage of keeping
vibrations away from machine frame 1.
If desired, more than one vibrator may be arranged between the
pressure means 15 and the car frame 16 so that only vibrations in a
horizontal direction are transmitted to the frame. If the maximum
vibratory force is chosen to equal the pressure force of ram 15,
the track will be subjected to a pulsating stress between zero and
twice the pressure of ram 15. In this manner, considerable pressure
may be exerted upon the track without unduly increasing the weight
of the machine.
As shown in FIG. 7, the upper end of pole 31 of measuring device 7
is glidably guided in a bushing in frame 1 and carries
potentiometer 72 which is adjusted by a fork 71 holding the
reference wire 5, the potentiometer producing a control signal
corresponding to the track position in a manner well known in track
leveling operations.
FIG. 8 illustrates a hydraulic motor 29 associated with each
bearing box 27 so that each wheel 28 is pressed against the rail
head it grips. Each bearing box carries a transverse block 34, the
inner ends of blocks 34 being interconnected by connecting block 35
which is pivoted to the transverse block ends at 36. This
arrangement makes it possible for the wheels 28 to adapt to changes
in the track gage (see also FIG. 13).
FIGS. 9 to 14 show modifications of means for transmitting
horizontal vibrations or oscillatory forces to the track, such
means being adaptable to varying track gages and changing widths of
the rail heads.
While it would be possible to use only a single double-beveled
wheel for the transmission of the horizontal vibrations to the
track, it is preferred to use at least one such wheel for each rail
so that both rails may be vibrated simultaneously and thus to
relieve undue pressure on the fastening means which attach the
rails to the ties.
The simplest vibration transmitting means is illustrated in FIG. 9
wherein two double-beveled wheels 41 are journaled on transverse
axle 40 at a fixed distance from each other. The V-shaped
peripheral grooves of the wheels have a relatively small apex angle
and the rail heads are received in these grooves with some play.
Vibrating means 42 is arranged to impart a horizontal oscillation
to axle 40, this oscillation being transmitted by wheels 41 to
rails 6. As indicated by the arrows, the vibrating means comprises
a pair of unbalances rotating in opposite directions so that the
vertical vibrations are substantially eliminated and only the
horizontal vibratory components remain. Since the rail heads are
received in the wheel grooves with play, this arrangement will
adapt to varying widths of the rails heads as well as small changes
in the track gage.
In the embodiment of FIG. 10, two parallel transverse axles 40 are
spaced from each other. The opposite ends of the adjacent axles
carry double-beveled wheels 41 gripping a respective one of heads
of rails 6 while the other end of each axle carries a smooth roller
43 running on top of the rail heads. The wheels and rollers are
mounted on the axles at a fixed spacing but since the axles are
laterally movable independently of each other, this arrangement
permits a much wider adaptation to varying track gages than the
embodiment of FIG. 9. The axles may, if desired, be journaled in a
frame which is laterally movable. Such gage changes will not
influence the transmission of vibrations from the axles to the
track due to changes in the track gage.
In the illustrated embodiment, vibrating means 42 are mounted on
each axle 40 to impart horizontal vibrations thereto in a manner
described in connection with FIG. 9 but care must be taken for the
two vibrating means to rotate synchronously and in the same phase
so that the same vibratory force is exerted upon both rails of the
track. It would be possible, of course, to replace the two separate
vibrating means by a single vibrator arranged to impart horizontal
oscillations to both axles simultaneously.
FIG. 11 shows another modification of vibration transmitting means
useful for the adjustment to variations in the track gage. A single
transverse axle 40' carries two double-beveled wheels 41, 41',
wheel 41 being mounted on the axle against transverse movement in
relation thereto when a hydraulic motor enables the wheel 41' to be
transversely moved along the axle for changing the distance between
the wheels and thus to adapt them to different track gages.
The hydraulic motor comprises a cylinder 44 whose end walls define
aligned bores through which axle 40' passes in a fluid-tight
manner, wheel 41' being carried by the cylinder. The cylinder is
glidably mounted on collar 45 of axle 40'. The collar functions as
a piston when pressure fluid is delivered to, or removed from, the
cylinder chambers through conduits 46 and 47, the flow of the
pressure fluid moving the cylinder laterally on the axle. To avoid
interference with the transmission of the vibrations produced by
vibrating means 42 from axle 40' to the wheels and the track rails
gripped thereby, a stop device 48 is provided to hold the wheel 41'
in an adjusted position. This device consists essentially of a
two-way solenoid valve which can be moved into a stop position
which prevents delivery or removal of pressure fluid from the
cylinder chambers so that there can be no relative movement between
piston 45 and cylinder 44.
In the embodiment of FIG. 12, the double-beveled wheels 41 are
journaled in the lower ends of carrier arms 50 which are pivotal
intermediate their ends about fulcrum axes 51 extending
substantially in the direction of the track to enable the carrier
arms to be pivoted in a vertical plane transverse to the track. The
upper ends of the carrier arms are linked to double-acting,
pressure fluid operated adjustment device 52. By delivering and/or
removing pressure fluid through conduits 53 and 54, the adjustment
device will pivot the carrier arms and thus adapt the wheels 41 to
variations in the track gage.
While the fulcrums 51 may be mounted on box-shaped carrier 24 of
the auxiliary car 13 (see FIGS. 5 to 8), if desired, it is
preferred, as shown in FIG. 12, to couple the fulcrums by a rigid
carrier 55 for vibrating means 42 while the upper ends of the
carrier arms 50 are guided in slotted guides in the main machine
frame. In this manner, the vibratory forces are transmitted to the
double-beveled wheels along the main axis so that the carrier arms
may oscillate together with the laterally adjustable carrier 55
without the adjustment device 52 being unduly subjected to
vibrations.
It would also be possible to connect the vibrator means directly
with the carrier arms for the wheels or to mount them directly
thereon and to operate them synchronously and in the same
phase.
Somewhat similarly to FIG. 8, the embodiment of FIG. 13 has two
double-beveled wheels 41 mounted on the short arms of two-armed
levers 56, 56 which are pivoted intermediate their ends to frame 16
of an auxiliary car, for pivoting in a vertical plane transverse to
the track about fulcrums 57. The ends of the other lever arms are
linked together by connecting link 58 whose ends are pivoted to the
other lever arm ends at 59, 59. This arrangement makes it possible
to adapt the wheels to varying track gages, wheels 41 assuming the
position indicated in broken lines at the left of the figure when
the track gage decreases while the wheels swing the other way when
the track gage becomes larger. Vibrating means 42 are mounted on
the car frame to impart horizontal oscillations to the wheels.
In the embodiment of FIG. 14, horizontal vibrations are transmitted
to the track in a manner similar to that of FIG. 12, but, instead
of being transmitted to the track rails, as in the embodiments of
FIGS. 9 to 13, they are transmitted to the ends of the track ties.
This embodiment is particularly useful when concrete ties are
used.
As will be seen in FIG. 14, carrier an 60, 60 are spaced apart a
distance corresponding roughly to the length of the ties and are
pivotal in a vertical plane transverse to the track about fulcrums
61, 61. Pressure fluid operated adjustment devices 62, 62 are
linked to the upper ends of the carrier arms while the lower
carrier arm ends have pressure plates 63, 63 which may be pressed
against the tie ends by operation of the adjacent devices. Fulcrums
61 are connected by rigid carrier 64 to which horizontal vibrations
are imparted by vibrator 65 which, in the illustrated embodiment,
has the form of a eccentric shaft. The entire vibrating arrangement
may be vertically adjusted by means of hydraulic motors 66.
It is one of the essential features of the present invention to
couple the reference system, i.e. the means for surveying and
indicating the level of the track, with the means for downwardly
pressing and horizontally vibrating the track so that the operating
parameters may be controlled so as to reposition the track at the
desired level. Therfore, the apparatus comprises a reference system
which includes a measuring device for ascertaining the difference
between the actual and the desired track level, which is well known
per se in the track leveling art, and operatively coupled thereto a
control circuit responsive to the track level measurements for
actuating the downward pressure and horizontal vibrating means in
dependence on, or a function of, error signals produced by the
measuring device at successive track points.
FIGS. 15 to 20 illustrate different embodiments of such controls
enabling selected operating parameters for the track leveling
operation, such as the downward pressure force, the frequency
and/or amplitude of the horizontal vibrations, and the duration of
the pressure and/or vibrations, to be controlled in dependence on
an initial error signal, i.e. an initial measurement of the
distance between the track and the reference line which indicates a
deviation from the desired track level, or on continuous and
successive error signals corresponding to successive track points
traversed by the continuously advancing machine.
The circuit diagram of FIG. 15 shows a control enabling the
downward pressure force exerted upon the track to be controlled in
response to a continuous measurement of the difference between the
actual and the desired track level. This control circuit comprises
a bridge circuit 70 which includes potentiometer 72 (see FIG. 7)
whose output signal is adjusted by fork 71 which holds reference
wire 5 and, therefore, is moved in dependence on the wire position,
i.e. its distance from the actual track level. Thus, the output
voltage of the potentiometer is proportional to the actual track
level as compared to the desired level which is set by the
reference wire. The resultant output signal of bridge circuit 70
and a signal corresponding to the desired track level are compared
in amplifier 73. The resultant reference signal is amplified in the
amplifier and forms the output signal of the amplifier, which is
proportional to the difference between the actual and the desired
track levels. The amplified output signal is transmitted to
solenoid valve 74 which is continuously adjustable to control and
adjustment of the valve in response to the measured track level
error. Valve 74 is arranged in the hydraulic fluid flow circuit
delivering hyraulic fluid to the downward pressure applying motors,
for instance hydraulic motors 9 or 15 (FIGS. 1 and 2), to control
the hydraulic fluid delivery, i.e. the pressure, in proportion to
the amplified control signal coming from bridge circuit 70 and
amplifier 73.
The hydraulic fluid flow circuit comprises a hydraulic fluid sump
whose fluid delivery line is connected to the input of constant
speed pump 75. The output of the pump leads to slide valve 76 which
controls the fluid flow to rams 9 or 15 so that it stops fluid
delivery entirely when the control signal is zero, i.e. the track
has reached the desired level, while the fluid flow is varied by
valve 74 in response to variations in the control signal. A signal
indicator 77, such as an amperemeter, is arranged in the electrical
circuit between amplifier 73 and valve 74 so that the size of the
control signal may be read by an operator who is thus enabled to
see the extent of the required track repositioning.
While the control signal, which is proportional to the track level
error signal, has been used to control the downward pressure on the
track in the embodiment of FIG. 15, FIGS. 16 and 17 illustrate
control circuits which control the frequency of the horizontal
vibrations imparted to the track in response to such control
signals. In these embodiments, the structure and operation of
circuit elements 70 to 73 are identical to those of FIG. 15, the
embodiment of FIG. 16 also providing amperemeter 77.
In the control circuit of FIG. 16, the control signal is
transmitted to valve 80 to control the amount of hydraulic fluid
flowing through hydraulic fluid circuit 81. The circuit 81 includes
the constant speed pump 75 which receives hydraulic fluid from
hydraulic fluid sump 83 wherein the hydraulic fluid is held at
atmospheric pressure, and also hydraulic motor or motors 82 which
drives or drive the vibrating means for imparting horizontal
oscillations to the track. The output of motor or motors 82 is
proportional to the hydraulic fluid throughput in circuit 81
controlled by valve 80, i.e. proportional to the control signal,
the changing motor output correspondingly varying the horizontal
oscillations or vibrations. For instance, if the frequency of the
vibrations was near the resonance point of the track at the
beginning of the operations at a given difference between the
actual and the desired track levels, it will be changed away from
resonance as the track level approached the desired level.
In the control circuit of FIG. 17, the frequency of the vibrations
is controlled only by electrical means. Here again, the structure
and function of circuit elements 70 to 73 are identical with those
of FIG. 15 and, therefore, require no further description. However,
the hydraulic fluid circuit 81 of FIG. 16 is replaced by electrical
circuit 90. Direct current drive motor 91 for the vibrating means
is arranged in shunt in circuit 90. The control signal is
transmitted from amplifier 73 to drive motor 94 which moves sliding
contact 93' of variable resistance 93 in circuit 90 so that the
power supplied to field coil 92 of direct current motor 91 is
changed in proportion to the control signal. This changes the
rotational speed of drive motor 91 and correspondingly the
frequency of the vibrations produced by the vibrating means driven
by motor 91. If the control signal were sufficiently amplified in
amplifier 73, it could be used directly for the adjustment of
variable resistance 93 without interposition of motor 94.
FIGS. 18, 19 and 20 show controls for changing the amplitude of the
horizontal vibrations in response to the error signal by switching
a selected number of vibrators on or off.
Referring to the circuit diagram of FIG. 18, two separate control
circuits I and II are provided for operating drive motors 100 and
101, respectively, for the vibrating means. The two control
circuits are closed, i.e. power is fed to the drive motors, by
closing switches 102 and 103, respectively. Opening and closing of
the switches is controlled by switch tripping relays 104 and 105,
respectively which are operated mechanically directly by camming
surface 106 affixed to the pole of measuring device 7. The distance
between the camming surface 106 and reference wire 5 is constant.
Switch tripping relays 104, 105 are mounted on rolls 8 or 14 (see
FIGS. 1 and 2) so that the position of the camming surface 106 in
relation to relays 104, 105 will depend on the level of the
track.
If the actual track level is above the desired track level within a
predetermined normal range of magnitude, camming surface 106 will
actuate only relay 105 (as shown in FIG. 18) so that only control
circuit I is closed to operate the vibrating means drive motor 100.
However, if the actual track level is particularly high so that
increased force is desirable for pressing the track down to the
desired level, camming surface 106 will also actuate relay 104 to
operate motor 101 in control circuit II. This will increase, for
instance double, the amplitude of the vibrations.
Substantially the same operating principle is essentially followed
in FIG. 19, except that the electrical control circuits I and II
are replaced by hydraulic fluid circuits I' and II'. In this
embodiment, camming surface 106 is mounted on the pole of measuring
device 7 and remains at a constant distance from the rail on which
the pole for measuring device 7 rides. Relays 104, 105 are mounted
on the frame of the apparatus or on pressure rolls 8 or 14 and will
be sequentially tripped as the pole rises. Sequential operation of
the relays will sequentially operate solenoid slide valves 112 and
113 placed in the respective hydraulic fluid circuits delivering
oil from sump 111 to constant speed pumps 109 and 110,
respectively, supply of hydraulic fluid operating hydraulic drive
motors 107 and 108, respectively, for the vibrating means. Thus,
the extent of the required correction stroke for pressing the track
down to the desired level controls the operation of the vibrating
means in the manner described in connection with FIG. 18.
FIG. 20 shows a control circuit diagram for controlling the
stepwise actuation of additional vibrators for increasing the
vibration amplitude as well as additional hydraulic rams for
increasing the downward pressure on the track in proportion to the
length of the correction stroke required to reposition the track at
the desired level.
The control circuit elements 70 to 73 are again the same as those
described in connection with FIGS. 15 to 17, providing a control
signal at the output of amplifier 73 which is proportional to the
track level error. This error signal is transmitted to computer 120
which classifies the signal into individual signal steps, the
illustrated embodiment providing three signal steps, the three
resultant output signals of computer 120 operating solenoid slide
valves 121, 122 and 123 which control hydraulic drive motors 124,
125 and 126 sequentially, the valves and associated drive motors
being arranged in three separate hydraulic fluid circuits. The
drive motors operate the vibrating means. Furthermore, hydraulic
rams 130, 131 and 132 for experting downward pressure on the track
are also mounted in the respective hydraulic fluid circuits, the
pressure in the latter motors being controlled by pressure reducing
slide valves 127, 128 and 129, respectively. These valves are also
controlled by the output signals from computer 120.
If the output signal of amplifier 73 indicates a relatively small
track level error, it will be classified only in one step of
computer 120. Thus, only a single vibrating means drive motor and a
signle downward pressure ram will be actuated. As the level error
increases, producing an error signal at the output of amplifier 73
proportional thereto, the computer will sequentially actuate the
additional vibrating means drive motors and downward pressure rams.
A further differentiation in the force applied to the track may be
achieved by using vibrators with different amplitudes and rams with
different pressures. It would also be possible, of course, to
operate the vibrating means and the downward pressure rams
independently by computer 120.
As will be obvious from the above description of certain now
preferred embodiments of the present invention, apparatus according
to this invention makes it possible to do track maintenance work
attuned most sensitively to various requirements and conditions
encountered in compacting ballast underneath a track and
positioning the track at a desired level. Thus, it is possible to
control not only the speed in which the desired track level is
reached but also the nature of the ballast tamping. Since these
factors depend at least one three parameters, i.e. the downward
pressure force, the frequency and the amplitude of the horizontal
vibrations to which the track is subjected, variations in these
parameters may be variously controlled and coordinated to meet all
requirements in a most sensitive manner. Furthermore, in a
continuous track work operation, it is possible to operate the
parameters sequentially at any given track point. It is also
possible to "anticipate" an observed track depression of excessive
magnitude before this point is reached by lifting the track at this
point particularly high.
The invention may be advantageously combined with a mobile track
leveling and lining machine of otherwise conventional structure,
the track tamping, leveling and lining means being mounted on the
machine frame ahead of the means for vibrating the track
horizontally and pressing it downwardly, in the working direction
of the machine.
An apparatus of this type is shown in FIG. 21 wherein an elongated
machine frame runs on the track on wheels 2, 2, tamping assembly
140 being mounted on an overhanging frame portion whose front holds
track jack 141 for leveling and/or lining the track, the leveling
being effected in relation to reference line 5'. A mobile track
working machine of this general type is shown, for instance, in
U.S. Pat. No. 3,211,109, dated Oct. 12, 1965, but any other track
leveling and/or lining machine may be used. Analogous to the
embodiment of FIG. 2, auxiliary car 13 with its gear according the
the invention, is mounted intermediate the machine wheels.
With a machine of this type, the track may be raised by jack 141,
at which time it may also be lined by the jack, the ballast may be
tamped underneath the ties by assembly 140, and the track is then
pressed down to the desired track level while being horizontally
vibrated at any selected track point according to the invention,
the repositioning of the track simultaneously causing compaction of
the ballast thereunder.
It will be clearly understood that the present invention is not
limited to the specifically described embodiments thereof. For
instance, while one type of measuring device has been described and
illustrated, many devices are known and useful for the practice of
this invention for indicating a track level error and producing a
proportional error signal for controlling track leveling
mechanisms. Such devices may work with reference beams of
electromagnetic radiation, such as light or laser beams, instead of
reference wires, as illustrated herein.
Furthermore, any suitable vibrating means may be used for imparting
substantially horizontal vibrations or oscillations to the track,
including rotating unbalanced weights, vibrating rams or eccenter
shafts. The only essential characteristic of the vibrating means is
that it has a marked horizontal component for imparting a
substantially horizontal vibration to the track. It is also
essential that the means for transmitting the vibrations to the
track is so arranged that the track will vibrate with substantially
the same frequency and amplitude as the controlled vibration of the
vibrating means.
While hydraulic rams have been illustrated for exerting a static
downward pressure on the track, spindle-driven or like rams could
equally used for this purpose, the type, arrangement and number of
rams varying greatly according to requirements and conditions. Any
desired dynamic pressure component may be produced not only by the
illustrated vibrators but also by other suitable pulsors. Selected
combinations of means for producing static and dynamic pressure
components will result in pressure forces of a type and magnitude
encountered when trains pass over the track. When the force of the
downward pressure is controlled by switching on additional rams,
the sensitivity of the control will depend on the number of the
rams provided.
While a number of controls have been illustrated, this does not
exhaust the possibilities. For instance, the controls for the
pressure, the frequency and the amplitude of the vibrations may be
combined in any desired manner. Thus, the illustrated control
diagrams will be understood to show only the principles of useful
controls.
We have found that track surfacing according to the present
invention holds the track at the desired level for a very long
period of time since it compacts the ballast to an extent
equivalent to that usually accomplished only by long and extensive
train traffic and the resultant pressures and vibrations to which
the passing trains subject the ballast. Furthermore, such track
surfacing also results in a considerable compaction of the ballast
at the ends of the ties, which has a most advantageous effect on
the lining of the track.
The metes and bounds of the invention are defined by the appended
claims.
* * * * *