Note: Descriptions are shown in the official language in which they were submitted.
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APPARATUS AND METHOD FOR HANDLING OF RAILWAY
SLEEPERS
The present invention relates to the field of railway infrastructure. More
specifically, the present invention is directed towards an apparatus and
method for the handling of railway sleepers or bearers (known as "ties" in
USA/Canada) for the installation and replacement of railway infrastructure.
Today there are a large number of specialised machines used in the
installation and maintenance of the railway infrastructure. Some of these
machines are designed to run on both road and rail, with alternate wheels
for each surface. Other machines, including very large and heavy
machines, run on rail only. Lifting machines are also known which can
span a whole rail track and which run on "caterpillar" type tracks on the
ballast either side of the railway line.
The present applicant has developed further apparatus which improve the
efficiency of handling railway rails, described for example in the applicant's
previous applications, such as WO 2005/095716 A and WO 2009/050439.
The transportation and installation of continuous welded rail in lengths
over two hundred metres is handled with ease.
In the course of installing or renewing a railway, there is a need to handle
large numbers of railway sleepers, as well as lengths of rail. In order to
assist in this, machines have evolved with specialised functions for the
lifting and laying of railway sleepers. Typical machines used to lift and lay
railway sleepers are large, expensive, impose great disruption on the rail
network and require a relatively large number of skilled personnel to
operate. For example, certain machines operate over two or more rail
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tracks, with a lifting machine working on one track while riding on an
adjacent track. This requires two teams of people working on each track,
which is expensive and time consuming. This also disrupts traffic on the
adjacent track and also prevents this type of machine operating on single-
track routes. Furthermore, the machines also operate within touching
distance of overhead power lines. This therefore requires the isolation of
the power lines for the duration of the work.
Furthermore, in the installation of a railway, it is essential that the
railway
sleepers are spaced from one another by a predetermined distance before
the rails forming a railway line are attached thereto. While the above-
referenced machines are capable of laying individual sleepers in a spaced
relationship, the sleepers are then required to be manoeuvred into the
correct position. This task is commonly referred to as "fine lining" and
required to be done manually. This task is time consuming and labour
intensive.
It is an object of the present invention to provide alternative methods and
apparatus for the laying and alignment of railway sleepers.
According to a first aspect of the present invention there is provided an
apparatus for handling railway sleepers and placing them with a desired
spacing on a railway bed, the apparatus comprising:
a mobile chassis;
an elongate support carried on the chassis and long enough to
span several sleepers at said desired spacing and adapted to be
supported above said railway bed;
a number of flexible tethers depending from respective points
spaced along said support and adapted to suspend a batch of sleepers
from said support;
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an alignment template extending beneath the elongate support and
formed so as to engage the suspended batch of sleepers simultaneously
as a group and fix their positions with the desired spacing; and
a mechanism whereby the alignment template and suspended
sleepers are made movable relative to each other so as to permit a
sequence of lifting, aligning and depositing batches of sleepers.
The apparatus may include a mechanism for increasing vertical separation
between the elongate support and the alignment template, while the
tethers remain of constant length so as to bring the template and sleepers
into and out of engagement. Alternative mechanisms can be envisaged
which effectively shorten and lengthen the tethers in a ganged fashion or
sequentially, but simply moving apart two beams allows a very simple
mechanism.
One of the elongate support and the alignment template may be fixed
relative to the chassis, while the other of the elongate support and the
alignment template is mounted to move relative to the chassis.
In a preferred embodiment, the alignment template is formed on the
underside of the chassis structure, while the elongate support is supported
above the chassis and moveable in a vertical direction relative to the
chassis.
Preferably, the apparatus is arranged to support a batch of at least seven,
preferably more than ten or even more than twenty railway sleepers. The
number fourteen in particular corresponds to the number of steel sleepers
in a conventional 'half-chord' length of track in the UK railway system. In a
large version of the apparatus, twenty eight sleepers could be held in one
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batch. Other
numbers may suit different national conventions, or
specialised tracks within the UK system.
The tethers may comprise chains.
Each tether may terminate with a hook adapted to engage a hole in the
upper face of a steel sleeper. Alternatively the tethers and hooks may be
adapted to engage the ends of sleepers, or even parts of the rail shoes.
The chassis may include one or more mounting points for mounting the
apparatus to a vehicle or vehicles.
In one embodiment, the chassis has a mounting point at each end,
whereby it can be supported and transported by a pair of tractor units.
Alternatively, particularly for longer examples, the chassis has mounting
points spaced inward of the ends, to minimise sagging of the chassis
under load.
The chassis may include means for lowering the template and sleepers as
a group to the railway bed. Alternatively such raising and lowering
operation may be implemented by actuators on the vehicle(s).
The apparatus in the preferred embodiment is provided in combination
with a pair of tractor units, each tractor unit having a coupling to support
the chassis, each coupling including an actuator to raise and lower the
apparatus, with and without sleepers suspended from it, to different
heights above the ground.
Preferably each tractor unit can straddle a width greater than 2.4 metres,
thereby to pass clear over a line of laid sleepers without disturbing them.
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In one embodiment, the tractor units can also retract to pass through a
gap less than 2.6 metres, for example.
Preferably the apparatus can be raised to a height sufficient to clear
5 stacks of four or more steel sleepers.
In a first type of embodiment, the apparatus is adapted to lift one batch of
sleepers from the tops of pre-arranged stacks. In another type of
embodiment, the apparatus is adapted to lift and carry two or more
batches of sleepers in stacked form, so as to deposit each batch from the
bottom of a stack. This allows batches to be laid from stock without
returning to the stock location between laying each batch. Obviously the
frame and vehicles must be strong enough to carry the weight of plural
batches.
Preferably, the coupling permits horizontal adjustment of the position of
the frame relative to the ground. In this way the final position of the
sleeper batch can be adjusted without fine positioning of the vehicle.
The horizontal adjustment may be powered or manually operated.
Preferably, the tractor units have ground engaging rolling means in the
form of elongate tracks.
The invention further provides methods of aligning & depositing batches of
sleepers on a railway bed, and methods of lifting, transporting, aligning
and depositing batches of sleepers from a stockpile along a railway bed.
The invention provides a first method of distributing sleepers on a railway
bed, comprising the steps of:
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- depositing a number of stacks of railway sleepers in a stockpile,
including a number of stacks spaced to match the spacing of the template
in an apparatus as set forth above;
- manoeuvring the apparatus above the stockpile and hitching
respective tethers of the apparatus to an upper sleeper in each stack;
- subsequently operating the mechanism of the apparatus to bring
the tethered sleepers and template into contact and positioning the
apparatus so that each of the tethered sleepers is above an individual
target location;
- subsequently lowering the apparatus to place the tethered sleepers
at their target locations; and
- releasing said tethers and removing the apparatus to repeat the
operation with a further batch of sleepers.
The invention provides a second method of distributing sleepers on a
railway bed, comprising the steps of:
- depositing a number of stacks of railway sleepers in a stockpile,
including a number of stacks spaced to match the spacing of the template
in an apparatus as set forth above;
- manoeuvring the apparatus above the stockpile and hitching
respective tethers of the apparatus to a number of sleepers in each stack;
- subsequently operating the mechanism of the apparatus to bring
the tethered sleepers and template into contact and positioning the
apparatus so that each of the tethered stacks of sleepers is above an
individual target location;
- subsequently lowering the apparatus to place the tethered stacks of
sleepers at their target locations; and
- releasing said tethers from a lowest sleeper in each stack and
removing the apparatus and the remaining sleepers in each stack, so as to
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repeat the operation with a next lowest sleeper until the entire stack has
been deposited.
In this method, the need for journeys of the apparatus to re-stock is
reduced.
In a preferred embodiment, the sleepers are engaged with the template
prior to transporting the apparatus and sleepers to the target location. The
template can then restrain the sleepers against swinging movements.
In either method, the apparatus may be supported and manoeuvred by a
pair of tractor units, pivotably mounted to support the apparatus at
respective locations along its length, and provided with ground engaging
rolling means, such as caterpillar tracks, spaced widely enough to straddle
the laid sleepers without rolling on them.
The method may further comprise a step of transposing a pair of rails onto
the deposited sleepers and fixing the rails to the sleepers to complete a
section of railway.
Further method features will be understood from a consideration of the
features of the apparatus as set forth above, as well as the embodiments
described below with reference to the drawings.
The invention further provides a railway installation installed by a method
as set forth in the preceding paragraph.
There is further disclosed a spacing and/or lifting arrangement specially
adapted for "twin-block" sleepers.
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BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention will now be described, by way of example
only, with reference to the accompanying drawings in which:
Figure 1 is a perspective view of a sleeper handling apparatus according
to an embodiment of the invention, in operation (tractor units not to scale);
Figures 2a, 2b and 2c are schematic side elevations showing the
apparatus in different stages of operation;
Figure 3 is a schematic plan view of the apparatus carrying a set of
sleepers;
Figures 4 and 5 are detailed views of two different types of sleeper-
engaging hooks and chains;
Figures 6a and 6b show the apparatus in plan view depositing sleepers on
a track bed and moving across the railway track, respectively;
Figure 7 shows an alternative form of apparatus suitable for handling
larger batches;
Figures 8a-8d show part of a modified form of the apparatus, and
corresponding process steps in handling a representative stack of
sleepers in a modified process;
Figure 9 shows apparatus in use with modified tractor units, for
transporting and/or deploying sleepers and "panels" in confined spaces;
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Figures 10a-10c show an alternative form of sleeper, of a "twin-block"
type; and
Figure 11 illustrates a modified form of spacer for correct spacing of twin-
block sleepers.
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DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
Figure 1 shows a novel sleeper handling apparatus in the middle of
handling a set of seven pressed steel railway sleepers ('ties' in
5 US/Canada). The apparatus comprises a lifting and alignment frame 100
supported between a pair of self-propelled vehicles or tractors 102, 104.
The length of the frame 100 is such that seven sleepers 106 can be
accommodated with a standard spacing.
10 Each tractor 102, 104 comprises a self-propelled vehicle with a pair of
caterpillar tracks and a chassis elevated so as to leave a working space
between the tracks and open to front and rear. Tractors 102 and 104 are
shown not to scale in the drawing, so as to maximise detail of the lifting
and alignment frame 100. In reality, the space between the tracks and
beneath the vehicle chassis is such as to make the vehicle to straddle a
width greater than the length of the sleepers, with the tracks running on
the ballast either side of the railway. The width of the tractor on the
ground may be 9-10 feet (2.7 ¨ 3.9m), for example, so as to straddle a gap
of 8 feet (2.4m) or more, depending on the maximum length of sleepers to
be straddled. (The scale is more realistic in Figures 3 and 6a/6b).
Each tractor 102, 104 is provided with an engine and hydraulic power
generator not shown), which can then be controlled manually or
electronically to propel and steer the vehicle via its motorised tracks. The
tractors are arranged both to support the frame 100 and to adjust its
elevation at each end relative to the ground, via actuators 134, 136
mentioned further below.
Turning to the lifting and alignment frame 100 itself, this comprises firstly
an elongate lower frame 112 comprising an open structure of two parallel
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box-section steel side beams and a few cross members for rigidity. The
lower frame 112 forms effectively a mobile chassis for the apparatus,
supported at each end by connection to the tractors 102, 104. A lifting
beam 114 lies generally along the top of frame 112, and is separable from
it by a few tens of centimetres elevation. A pair of hydraulic rams 116 are
mounted to thrust down from the beam 114 onto cross members 118 so
as to force the elevation of the beam 114. Guides 120 are provided to
maintain the alignment of the beam and frame, and to limit the elevation of
the beam. On the underside of the frame 112 along each side beam there
are provided sets of projections 122, which are spaced in pairs according
to the width of each sleeper, and according to the desired spacing
between sleepers. The underside of the frame 112 thus serves acts as a
jig or template for repeatable, accurate positioning of batches of sleepers
at a time.
By operation of respective actuators 134 and 136 on the tractors 102, 104,
load frame 122 and beam 114 can be raised as a unit to different heights
above the ground. Independently, the vertical spacing between beam 114
and lower frame 112 can be increased or decreased by operation of the
rams 116. Hydraulic power linkages (not shown) are made between the
engines of the tractors 102, 104 and the rams 116.
Finally, the apparatus comprises a set of flexible tethers 124, by which
individual sleepers can be suspended from the beam 114. Each tether
comprises matching pairs of chains 126 or wires, joined by a central link
128 lying across the beam 114 to form a double pad eye. In the illustrated
embodiment, the links are welded at positions along the beam, directly
above the respective sleeper positions defined by the projections 122. At
the extremity of each chain 126 is a hook 138 adapted to engage a pre-
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existing hole in the sleeper, and to lift the sleeper securely. A suitable
form of hook will be described below, with reference to Figure 4.
Figures 2a ¨ 2c illustrate the operation of the apparatus in lifting and
aligning groups of railway sleepers, so that they may be transported and
deposited in pre-aligned batches. In the starting condition shown in Figure
2a, seven stacks of five or six sleepers each have been deposited at a
work site. These stacks are spaced with the spacing approximately equal
to the desired sleeper spacing, which corresponds, by design, to the
spacing of the tethers 124 and the projections 122 on the lifting and
alignment frame 100. The apparatus comprising frame 100 and tractors
102, 104 approaches the stock of sleepers from either the left or right
hand end as shown, the tractor 104 or 102, as the case may be, straddling
the stacks of sleepers until the frame 100 is positioned over the stacks as
shown. The actuators 134, 136 which can now be seen beneath the
tractors 102, 104 are operated to lower the frame 100, so that the tethers
124 can be attached by their hooks 138 to the topmost set of sleepers.
As shown in Figure 2b, the frame 100 is then lifted by operation of
actuators 134, 136, so that the sleepers 106 are suspended in a free-
hanging manner from the apparatus.
In Figure 2c, the rams 116 have been actuated to lift the beam 114 away
from the lower frame 112 of the lifting and alignment frame 100. By this
action, the sleepers are brought tightly against the underside of the frame
112, engaging with the projections 122 so as to nestle securely and
accurately against frame 112 with the desired spacing. As the tethers 124
are of equal length on each side of the apparatus and the lifting holes in
the sleepers are symmetrically spaced, the sleepers are also aligned
accurately in the transverse direction.
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At this point, the apparatus is in the state shown in Figure 1. Figure 3
shows in plan view the same apparatus with sleepers held against the
alignment frame. Also in Figure 3 the scale of the tractors 102 and 104
can be seen, by which the ground-engaging tracks 108 are spaced widely
enough that the full length of a sleeper can fit easily between them.
Actuators 134 and 136 can also be operated to move the ends of the
frame transversely for fine adjustment, as illustrated by double-headed
arrows.
Figure 4 shows in more detail a suitable form for the hook 138 to engage a
hole in the steel sleeper material. Length of chain 126 terminates in a
metal plate 140, which is generally flat so as to lie against the metal of the
sleepers 106. A short stub 142 of metal on the underside of plate 140 has
a length suitable to pass through hole 144 in the sleeper material. The
end of stub 142 is provided with a head 146 which is small enough to
permit the head 146 and stub 142 to enter the hole 144, but projects so as
to engage under the metal of the sleeper 106 when the chain 126 is pulled
in the direction shown by the arrow. Once the length of chain is in tension,
the hook formed by parts 140, 142 and 146 will not accidentally disengage
from the sleeper. On the other hand, as soon as the tension is released, it
is easy to engage and disengage. The use of chain 128 for the tether,
rather than a wire having stiffness, contributes to the predictable behaviour
of the hook engaging and releasing.
Figure 5 shows an alternative for us of hook 500. This is specifically
adapted for engaging a standard rail fixing 502 mounted on each sleeper
(see Figure 1). The example shown is for a Pandrol Fastclip TM fixing. The
hook comprises a bent '0' shape of metal plate. A first half 504 of the
plate is coupled to the chain 126, so as to align with the pulling force of
the
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chain as the sleeper is lifted. The other half 506 of the plate lies in a
plane
substantially at right angles to the pull, and includes cheek portions 508
defining a narrower opening 510 than the first half. The hook 500 is thus
adapted to slide onto the FastclipTM fixing and the cheeks 508 engage
shoulders on the fixing 502 to lift the sleeper.
Different forms of hook may of course be required to engage different
forms of fixing. Other types of hook may be adapted to engage under the
sleeper body itself, either at its extreme end or on either side. Lifting by
electromagnets or permanent magnets is also possible with steel sleepers.
The lifting may be entirely by magnetism, or magnets may assist in the
placement of mechanical hooks. The term "hook" is used in its broadest
sense, to cover any device for detachably engaging and lifting the
sleepers.
Figure 6a shows in plan view the apparatus setting down the spaced set of
seven sleepers on a track bed made of ballast, as part of a railway
replacement operation. Figure 6b illustrates the manoeuvrability of the
tracked tractor vehicles 102, 104, which can manoeuvre from trackside
across the rails and to straddle the rails by virtue of their rubber
caterpillar
tracks. Wedges can be carried to assist mounting the rails.
The numbers seven and fourteen are chosen particularly because, at least
in UK practice, a set of fourteen sleepers is conventionally referred to as a
"half length", twenty-eight sleepers a "full length", corresponding to a
traditional 60-foot rail. A commercial example of the apparatus might carry
fourteen sleepers or even twenty-eight at a time rather than seven, over a
length of roughly 10m or so (thirty feet). These lengths of sleepers can be
laid in a straight line, as shown in Figure 6a, or they may be laid in
successive chords of an arc, to create a curved section of track. A peg
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and string system is used to mark out the desired line in advance, in a
conventional manner. The side-to-side adjustment of the actuators 134,
136 is sufficient to place the entire group of seven sleepers in accurate
alignment at the desired location. The fact that the apparatus holds the
5 batch of sleepers in alignment and places them on the ground before
releasing tension in the tethers 124 means that the "fine lining" process
which is conventionally conducted manually has been eliminated.
Figure 7 shows a modified layout suitable for larger batches and/or
10 heavier types of sleepers. Rather than mounting the apparatus 700 to the
tractor units at its extreme ends, the mounting points may be roughly at 1/4
and 1/4 of the overall length, for example. Accordingly, the frame carrying
the sleepers extends through each tractor unit 102, 104 and out the other
side. This improves the balance of the beam, and reduces its tendency to
15 sag between the mounting points, compared with a beam of similar
rigidity
supported at its extremities. Where a segment of the curve is shorter than
the length of the apparatus, a smaller number of sleepers can be laid first,
and then the angle of the beam adjusted to lay the next segment.
The stacks of sleepers laid out ready for carrying and aligning using the
apparatus can be at the track side, or can be placed directly at the location
desired for the first seven/fourteen/twenty-eight sleepers. In other words,
the stacks may be placed such that, when the apparatus has lifted,
transported and deposited four sets of seven sleepers in the desired
alignment, the bottom set of sleepers are already at the desired place. If
necessary, the apparatus can be applied to lift, align and replace these
final sleepers without transporting them. An alternative embodiment in
which stacks are lifted is described below with reference to Figures 8a-8d.
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It should be understood that the spacing of the sleepers in the schematic
drawings of Figures 2a etc and 3 is much closer than in a normal
operation, simply for compactness of the drawing. The perspective view
of Figure 1 shows a more realistic spacing. If the spacing of the sleepers
and their individual width is such that another sleeper can fit between
adjacent sleepers, then the stack of sleepers from which stock is
transferred to the rail bed can be double density (i.e. fourteen stacks of
five or so sleepers). The frame can then be positioned to pick up seven
sleepers from the odd-numbered stacks, and then seven sleepers from the
even-numbered stacks alternately.
Figures 8a-8d illustrate part of an alternative apparatus 800 for use in a
modified process in which a whole stack is carried by the machine at each
position in the template, and batches of sleepers 106 are deposited singly
from the bottom of their stacks. Only one sleeper position is shown, it
being understood that the features shown are repeated at all positions for
a batch (seven, fourteen, twenty-eight etc.). Elements 812, 822 etc. of
apparatus 800 correspond to the like-numbered elements 112, 122 of
apparatus 100 described above. The key modification is that the chains
826 and hooks 838 are adapted to reach around the whole stack, so as to
lift as many sleepers as will fit: for example five in each stack are shown.
In the starting condition of Figure 8a, stacks are being carried to their
target position. In Figure 8b the lifting beam 814 is lowered to rest the
stacks on the ground. At Figure 8c the hooks are disengaged from the
bottom sleepers 106 and re-engaged on the second sleepers. At Figure
8d the beam 814 has been raised again to lift the remaining four sleepers
and carry them away.
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The travel of the beam 814 is increased compared with the example of
Figures 1 to 3. Alternatively or in addition, the chains 826 can be made
adjustable in length and/or provided with multiple hooks. This allows them
to lift 5, 4, 3, 2 or 1 sleepers in each stack. The apparatus as a whole
must of course be strengthened to carry the greater load.
The projections 822 of the template are shown unchanged in Figures 8a to
8d, but additional or modified guides may be provided to stabilise the
whole stack satisfactorily. As an example, Figures 8b and 8c show in
broken lines vertical guide bars 850 that may project downward from the
frame, either side of the stack. In this example the bars 850 are mounted
so as to move with the lifting beam 814, so as to allow the lower frame 812
to approach the ground unimpeded. In alternative embodiments, the bars
850 or other guides may be mounted so as to project a fixed distance
below the frame 812, forming a kind of 'magazine'. They may be
retractable independently of either the frame or the lifting beam, either by
an active mechanism or by 'floating' and rising upward, relative to the
frame of the apparatus, upon contact with the ground,
While the lifting and alignment frame 100 has been shown comprised of a
double-beamed lower frame 112 and an upper single beam 114, this
construction is by no means essential. Either or both of the moveable
elements can be considered as a frame or beam, and constructed
accordingly. Similarly, while the lower frame 112 is the part supported on
the tractors and the upper beam 114 moves relative thereto, the roles of
the upper and lower beams could be reversed. In such an embodiment,
the operation may become more complicated, as the height of the lower
beam above the ground would depend on the operation both of the
actuators 134, 136 and the rams 116 or equivalent. This complexity may
be overcome while retaining the overall benefits of the invention.
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Figure 9 shows a modified application of the apparatus 100, using
modified tractor units 902, 904. While tractor units 102, 104 of the
previous embodiments have a fixed spacing between the tracks, sufficient
to span completely the length of the sleepers, units 902, 904 have
telescopic arms, so that the ground-engaging tracks 108 can be drawn
into a narrower width, substantially the same as the sleeper length. The
upright legs of the tractor unit may also be telescopic so that the chassis of
each can be raised up and down, but that is not illustrated here.
As illustrated in Figure 9, this telescoping ability allows the tractor units
to
pass along a working area which is within or just a little wider than the
sleeper length. Confined widths can exist when laying or renewing track
on bridges or in tunnels, especially for single track but also for double
track railways. In such cases, even if there is space enough for the tracks
to run either side of the sleepers, it may not be rated for carrying a heavy
load. The tractors may be to retract from providing a width between the
legs greater than 2.4 metres, say, down to a situation in which the tracks
can pass through a gap of less than 2.6 metres.
In the situation shown in Figure 9, tractor 902 has retracted already to its
narrower width. For this purpose, a load is suspended between the
tractors without extending between the tracks of each tractor. As tractor
902 passes between obstructions 908, 910, tractor 904 in due course will
retract its tracks, following the envelope indicated at 912, 914, so that the
entire combination of tractors and load can pass through a gap little wider
than the sleeper length.
The load in this case need not comprise only sleepers, but could comprise
a complete "panel" comprising of rails and sleepers, allowing very rapid
removal of track sections from bridges, tunnels etc.. Hitherto, such
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operations in a confined width would require cranes and removal of very
short sections of the track. Where apparatus 100 is shown being used
with tractors 902, 904 in Figure 9, the longer apparatus 700 could be used,
provided that the parts between the tractor trucks are not loaded so as to
obstruct the telescoping movement. Apart from this change, there is no
need to deviate from the working methods described above. The tractors
in their retracted form can run on top of existing rails and/or sleepers, as
well as running on the empty rail bed.
While the embodiment shown has been designed for lifting steel sleepers,
the principle can be extended to other types of sleepers, for example wood
or concrete. Concrete sleepers are generally much heavier than steel
ones, so that a stronger frame and/or smaller batches of sleepers should
be contemplated. Again, none of this departs from the principle of the
invention.
As another example of a sleeper type, Figures 10a-10c illustrate a "twin-
block" sleeper 106', which is less common than steel or concrete sleepers
in the UK, but used in appropriate situations in the UK. The twin-block
sleeper 106' is a hybrid of a steel and concrete sleeper, and comprises
concrete end blocks 1002, 1004 tied together by a tie-bar 1006 of steel
angle bar. Figures 10b and 10c show cross-sections looking in opposite
directions along the tie-bar 1006. As can be seen in these cross-sections,
the angle bar that forms tie-bar 1006 is oriented in an asymmetrical
fashion and its relation to the sleeper centre line 1008 is different, looking
in each orientation. The orientation of sleepers at the work site may be
somewhat randomised, even if they are made and stacked initially all with
the same orientation.
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Figure 11 illustrates a modified frame 112' which is adapted to steady and
space these twin-block sleepers in a reliable fashion, irrespective of the
asymmetrical form of the tie-bar 1006, and irrespective of the orientation of
the tie-bar when presented to the frame 112'. Compared with the frame
5 112 of the Figure 1 embodiment, we see projections 122', which are
provided to engage and guide the sides of the tie-bars, in a similar manner
to projections 122 in the earlier embodiment. Because of the smaller
dimension of the tie-bar, however, projections 122' are much closer
together around each sleeper position. Depending on the degree of swing
10 expected before engagement, projections 122' may be larger than
illustrated. Centre lines 1010 indicate the desired centre line positions of
the sleepers when spaced. As further shown in Figure 11, the frame 112'
is provided with a rectangular recess 1012 between the projections 122' of
each pair. The width of recesses 1012 is selected and placed in relation
15 to the angled surfaces of projections 122' so that the tie-bars 1006 are
admitted slightly into the recess, abutting one or other inner face of the
recess, depending on the orientation of the tie-bar. By suitable
dimensioning of the recess, the centre lines 1008 of the sleepers can be
aligned with the desired positions 1010, irrespective of the orientation of
20 the tie-bar. The angled surfaces of projections 122' are provided
primarily
to guide the tie-bar into the recess, they may also be at an appropriate
angle, as shown, to support the "heel" of the angled bar.
While the spacing frame 112' adapted for twin-block sleepers has the
recesses on the underside, use of a recess for accurate centring of twin-
block sleepers is believed to be novel and patentable in more general
applications. For example, instead of drawing the sleeper tie-bars up to a
frame 112' having recesses 1012, they could alternatively be lifted and
spaced by a lifting bar placed under the tie-bars 1006, with recesses 1012
formed in its upper surface.
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21
While the separation of beam 114 from frame 112 is provided as a simple
means for tensioning the tethers 124 simultaneously, various mechanisms
can be envisaged for pulling on the tethers at the desired time. The beam
114 and/or frame 112 may be divided into sections, for example two
longitudinal half frames, which can move apart and/or pivot to cause the
engagement of the template with the sleepers.
The tethers may include some elasticity to account for slight variations in
their length; some fine adjustment of their length may also be provided in
the coupling to the beam 114 or hook 140. While simple triangular welded
steel projections 122 have been shown for enforcing the desired spacing
on the sleepers, all manner of formations can be envisaged, including
recesses in the frame 112, while fulfilling the same function. The
projections 122 and the location of the pad eyes 128 may be made
adjustable to achieve different sleeper spacings and/or to accommodate
different sleeper profiles.
The diesel and hydraulic power units and actuators (including rams 116) of
the illustrated embodiments can of course be replaced by electric or other
power source, or even manual jacks and winches.
The apparatus as described provides a useful companion to the railway
rail handling apparatus described in the applicant's previous applications,
such as WO 2005/095716 A and WO 2009/050439A.
CA 02751533 2016-06-28
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22
The scope of the claims should not be limited by the preferred
embodiments set forth in the examples, but should be given the broadest
interpretation consistent with the description as a whole.
