The present invention relates to a sealing plate for a
5 railway rail clip anchoring device and a sleeper
manufacturing method.
In the documents W093/12294, W093/12295 and W093/12296,
the present applicants disclosed a railway rail fastening
system in which a rail fastening clip is driven laterally
10 onto the rail and can be held in a clip anchoring device
(shoulder) in a "pre-assembly" or "parked" position in
which the toe portion of the clip does not bear on the
, rail. This enables railway sleepers to be preloaded at the
factory with clips which are held in the pre-assembly
15 position such that when the sleepers are delivered to site
the clips can simply be driven home once the rail is in
place. In addition, *hen maintenance of the rail or
sidepost insulators (which lie between the rail and the
shoulder) is subsequently required, the clip can be driven
20 off the rail back into the pre-assembly position, or
further into an "insulator-change position" in which the
clip does not overlie the sldepost insulator, so complete
withdrawal of the clip from the shoulder is not necessary.
Such clips are sometimes known as "switch-on/switch-off"
25 clips. Such a fastening system has proved to be very
successful, but the applicant is desirous of making
improvements to some aspects of its manufacture and use.
In a co-pending PCT application the applicants disclose
a shoulder in which the clip-engaging features on the lower
30 part of the walls of the shoulder are absent.
According to a first aspect of the present invention,
there is provided a sealing plate, for use with a rail clip
anchoring device having a head and a stem which extends
from the head into a concrete sleeper when the anchoring
device is in use, the plate being designed to extend over
the underside of the head when the stem of the device is
being set in a concrete sleeper, thereby to prevent ingress
of concrete into the head of the device, and to be retained
5 on the surface of the sleeper thereafter, wherein a major
face of the plate, which is uppermost when the sleeper is
in use, is provided with at least one clip seat portion for
receiving part of a rail clip.
Thus the sealing plate can replace the clip engaging
10 features omitted from the shoulder which is the subject of
the applicant's co-pending PCT application, and, if made of
plastics material, also allows weight and cost, to be taken
out of the overall assembly. The plate is desirably made,
for example, of nylon, glass-reinforced plastic or similar.
15 Preferably, the plate is formed such that a seal is
created around the periphery of the said major face of the
plate when pressure is applied to the other major face, and
is desirably made of plastics material.
Preferably, the plate is substantially rectangular in
20 outline.
Desirably, one edge of the plate has a cut-out portion
shaped for receiving a portion of the head of the anchoring
device adjacent to the stem thereof. The cut-out portion
may have a bevelled edge which matches a bevelled edge of
25 the said portion of the headof the anchoring device.
The plate preferably comprises locating means for
locating the plate on the head of the anchoring device.
The locating means may comprise at least one tab protruding
from a major face of the plate for engaging with a
30 corresponding feature on the anchoring device.
The or each clip seat portion may be of greater
resilience to wear than other parts of the plate. The clip
seat portions (heel seats) of the plate may be reinforced
with stronger material or with small steel bearing plates,
to cope with the loads on this part of the assembly
imparted by the heel portions of the clip.
The clip seat portion may comprise a projection, which
5 is preferably L-shaped in plan.
The clip seat portion may have a clip-receiving surface
which is shaped so as to match the profile of that part of
the clip which is to bear thereon. By shaping the heel.
contact areas so that they match the shape of the heel
10 bearing areas of the clip, the pressure on the plastic
plate will be reduced.
The major surfaces of the plate may be formed with one
or more apertures therethrough for receiving respective a
portion of the anchoring device which extends from the
15 underside of the head of the anchoring device.
The major face of the plate which is lowermost when the
sleeper is in use is preferably provided with strengthening
ribs which intersect to define a plurality of rebates.
Thus, the plate is effectively hollowed out underneath,
20 where possible, to reduce section thickness and material.
These voids (rebates) are filled with concrete during
sleeper manufacture, which means that the plate is fully
supported across its whole lower surface.
When a seallng plate embodying the first aspect of the
25 present invention is used in combination with a concrete
sleeper into which it has been set, the major face of the
plate which is uppermost when the sleeper is in use may
desirably be flush with the uppermost surface of the
concrete sleeper.
30 Typically, shoulders for retaining switch-on/switch-off
clips are secured to concrete railway sleepers (ties) by
embedding a stem of the shoulder in the concrete during
manufacture of the sleeper. The sleepers are manufactured
upside down, so t h a t t h e t o p of t h e f i n i s h e d s l e e p e r is
formed by t h e bottom of the mould pocket. During
manufacture, t h e p a r t s of the shoulder t h a t s t i c k up above
the f i n i s h e d sleeper t h e r e f o r e s t i c k down through apertures
5 cut i n t o the f l o o r of the mould pockets at appropriate
p o s i t i o n s f o r t h i s purpose. The stems of the shoulders t h a t
end up c a s t i n t o the concrete sleeper s t i c k up i n t o t h e
mould pocket before the concrete is poured. The first s t e p
i n the manufacturing process is t o t u r n t h e c a s t shoulder
10 upside down and push it down from above through an aperture
i n the mould pocket t o r e f u s a l . When the concrete has been
poured and allowed t o set, the s l e e p e r s are l i f t e d out of
the moulds and turned t h e r i g h t way up. A d i f f i c u l t y with
the process i s t h a t if the apertures i n the bottom of t h e
15 mould pockets a r e not a very close f i t around the edges of
t h e c a s t shoulders, concrete w i l l leak through the gap and
it may then s e t on t o p a r t s of the shoulder above the
f i n i s h e d concrete l e v e l and prevent the c l i p from engaging
properly. On the other hand, i f the aperture is too small,
20 a d d i t i o n a l dressing off of the shoulder is required, which
is very c o s t l y . Given t h a t c a s t i r o n shoulders are subject
t o r e l a t i v e l y wide t o l e r a n c e s - t y p i c a l l y f 0 . 8 m or more -
and t h a t the p a t t e r n s used t o produce them wear with time
and so the physical s i z e of the p a r t reduces with time, it
25 can be d i f f i c u l t t o achieve a good compromise between the
n e c e s s i t y of s e a l i n g and t h a t of ensuring f i t . This is
e s p e c i a l l y t h e case i f the shape of the aperture is
r e l a t i v e l y complex. Flexible r i m s f i t t e d t o the apertures
may be a p a r t i a l s o l u t i o n , b u t these wear and require
30 maintenance.
According t o a second aspect of the present invention,
there i s provided a method of manufacturing a concrete
sleeper with a t l e a s t one embedded r a i l c l i p anchoring
device of t h e type having a head f o r r e t a i n i n g a r a i l c l i p
and a stem extending from the underside of the head, i n
which method t h e f l o o r of a mould, from which the sleeper
is t o be formed, is provided with an a p e r t u r e , the head of
5 an anchoring device is i n s e r t e d through t h e aperture such
t h a t the head of t h e device extends out of the mould and
the stem of t h e device is located within the mould, and
concrete is introduced i n t o t h e mould, wherein before the
concrete is introduced i n t o t h e mould the aperture is
10 sealed off around its edges and around the underside of the
head of t h e anchoring device by placing a s e a l i n g p l a t e
over t h e a p e r t u r e on the f l o o r of t h e mould, the p l a t e
overlapping and s e a l i n g around the edges of the aperture
other than where the anchoring device is located and having
15 a mating i n t e r f a c e with the anchoring device such t h a t a
s e a l is formed therewith.
Thus, t h e s e a l i n g p l a t e may be used t o s e a l the
aperture i n the mould pocket and prevent the ingress of
concrete i n t o t h e head of the shoulder. When i n use the
20 sealing p l a t e is e f f e c t i v e l y glued on t o the top of the
concrete s l e e p e r , such t h a t its top face is f l u s h with the
face of t h e top s u r t a c e of the concrete on the sleeper top.
Preferably, before the s e a l i n g p l a t e is introduced
i n t o t h e mould, it is connected t o the anchoring device so
25 as t o extend over t h e underside of the head, the s e a l i n g
p l a t e being introduced i n t o tke mould together with the
anchoring device and located over the aperture when the
head is i n s e r t e d through the aperture. Thus, i f designed
t o i n t e r l o c k with the shoulder, t h e s e a l i n g p l a t e can be
30 accurately positioned with ease, and it cannot move up,
iforward or side-to-side. Nor can it move down or back
because it is bonded t o the concrete s l e e p e r .
It can e a s i l y be made so as t o have a simple o u t l i n e ,
which need not match t h e o u t l i n e of the shoulder, such as
rectangular, so the aperture can a l s o have a simple
o u t l i n e . I f formed a s a p l a s t i c moulding, t h e s e a l i n g
5 p l a t e can a l s o have a much t i g h t e r t o l e r a n c e than a castiron
p a r t , t y p i c a l l y +0.15mm. However, i f t h e s e a l i n g
p l a t e is made so as t o be s i g n i f i c a n t l y l a r g e r than the
aperture, n e i t h e r t h e exact s i z e nor exact shape of the
aperture is c r i t i c a l any longer.
10 When the aperture i n the mould is s u b s t a n t i a l l y
rectangular and a first face of the head of the anchoring
device abuts one side of the aperture, the s e a l i n g p l a t e is
preferably shaped so as t o mate with a second face of the
head of t h e anchoring device, opposite t o s a i d f i r s t face,
15 and t o overlap t h e edges of the aperture on t h e o t h e r three
s i d e s t h e r e o f . The edge of the s e a l i n g p l a t e which mates
with the second face of the head may be bevelled so as t o
match bevelling on the said second face. The s e a l i n g p l a t e
is preferably a p l a t e embodying the f i r s t aspect of the
20 p r e s e n t i n v e n t i o n .
Reference w i l l now be made, by way of example, t o the
accompanying drawings i n which:
Figure 1 shows a s e a l i n g p l a t e embodying the first
aspect of the present i n v e n t i o n , Figure 1A showing a
25 perspective view from above, Figure 1B showing a plan view
of the t o p s u r f a c e of the s e a l i n g p l a t e , Figure 1C showing
a plan view of the underside of the s e a l i n g p l a t e , Figure
I D showing a s e c t i o n a l view taken along t h e l i n e Y-Y i n
Figure l B , Figure 1E showing a f r o n t view of t h e sealing
30 p l a t e and Figure 1F showing a c r o s s - s e c t i o n a l view taken
along the l i n e Z-Z i n Figure 1B;
Figure 2 shows an anchoring device s u i t a b l e f o r use
with a s e a l i n g p l a t e embodying the f i r s t aspect of the
present invention, Figure 2A showing a perspective view
from above, Figure 2B showing a front view, Figure 2C
showing a part sectional view taken on the line Z-Z in
Figure 2B, Figure 2D showing a rear view, Figure 2E showing
5 a side view, Figure 2F showing a plan view from above,
Figure 2G showing a plan view from below and Figure 2H
showing a side view of another anchoring device suitable
for use with a sealing plate embodying the first aspect of
the present invention; and
I 0 Figure 3 shows a railway rail fastening assembly
employing a sealing plate embodying the present invention,
in which Figures 3A and 38 show the assembly in a side view
in which a rail fastening clip is in a pre-assembly
position with respect to the rail, Figure 3B being a part
15 cross-sectional view, Figures 3C and 3D show another side
view of the assembly in which the clip is bearing on the
rail, Figure 3D being a part cross-sectional view, Figure
3E shows a rear view of the assembly and Figure 3F shows a
perspective view of the assembly.
20 A plastic sealing plate 2 embodying the first aspect of
the present inyention will now be described with reference
to Figures 1A to IF. The sealing plate 2 has a first major
face 20 which is uppermost when the plate 2 is in use on
the top of a sleeper and a second major face 21 opposite
25 to the first. The sealing plate 2 is substantially
rectangular in outline, having a cut-out portion along one
side 22, defining ears 23 which ensure a seal at the
corners of a shoulder 1 located above the plate 2 within
the cut-out 22. The cut-out 22 has a bevelled edge 22a
30 which mates with a corresponding bevelled edge on the rear
face 15 of the shoulder 1. The cut-out 22 also has
radiussed recesses 24 for mating with corresponding
radiussed portions of the shoulder 1.
The first major face 20 of the sealing plate 2 is
formed with 'two clip seat projections 25, which are
substantially L-shaped and are located in respective
corners of the first major face 20 adjacent to the side of
5 the plate which is opposite to that having the cut-out 22.
The clip seat projections 25 have respective top surfaces
25a, which are planar in Figs. 1A to IF, but may have some
form of profile (see Fig. 3F) to match that of the part of
the clip which is to bear on the projections 25, with a
10 view to reducing plastic flow and wear in these areas. The
plate 2 may have reinforcement in the region of the clip
seat projections 25, for example the projections may be
formed of a stronger material or reinforced with small
steel bearing plates.
15 With reference to Figures 2A to 2G an anchoring device
(shoulder) suitable for use with a sealing plate embodying
the first aspect of the invention will now be described.
The anchoring device 1 shown in Figures 2A to 2G comprises
a head 1A from the underside of which downwardly project a
20 stem part 1B and two spaced-part tangs 1C. The stem part
1B comprises a substantially Y-shaped stem 100, connected
to the underside of the head 1A at the ends of upper arms
101 of the Y, and a bent part 102 at the other end of the Y
for resisting withdrawal of the stem from the concrete in
25 Qhich it is embedded when it is in use. As shown in Fig.
ZH, which shows another shoulder suitable for use with a
sealing plate embodying the first aspect of the present
invention, the underside of the shoulder 1 may be provided
with one or more webs 1D connecting the stem 100 of the
30 shoulder 1 to its head lA, instead or in addition to the
tangs IC (not shown in Fig. ZH), for assisting in
preventing .the shoulder 1 tipping forward when a clip is
driven into it.
The head 1A of the anchoring device 1 comprises two
spaced-part walls 10, connected together at one end of the
head lA, at the bottom of the walls 10, by a connection
portion 14. The top surface of the connection portion 14
5 is downwardly inclined and forms a ramp 140, while the
front surface of the connection portion 14 forms the front
face 12 of the shoulder 1. The end of the walls 10 at the
front end of the head 1A are connected to the front face 12
of the shoulder by curved portions 13.
10 The walls 10 extend outwardly at their tops to provide
respective clip-engaging surfaces 11 provided with two
clip-engaging projections llOA, 110B, which project
downwardly and are connected by means of a ramped surface
111 which inclines downwardly from the rear of the shoulder
15 1 to the front of the shoulder 1, for deflecting the leg of
a railway rail fastening clip. The front face 12 of the
shoulder 1 is provided with projections 120 for engaging
with the sleeper mould so as to set the shoulder at the
correct height in the mould before the concrete is
20 introduced. The shoulder 1 has a rear face 15 opposite to
the front face 12.
Referring once again to Figs. 1A to IF, apertures 26
are formed through the major faces 20/21 of plate 2 so as
to receive portions of the shoulder 1, namely the tangs lC,
25 which extend through the apertures 26 in the plate 2 into
the concrete of the sleeper. The major face 20 of the
plate 2 is also formed with upstanding tabs 27 which are
provided for cooperating with respective features on the
underside of the shoulder 1 to retain the plate 2 on the
30 shoulder 1 (and vice versa) before the plate 2 and shoulder
1 have been set into the concrete of the sleeper. If the
plate is to be used with a shoulder 1 as shown in Fig. 2H,
in which webs 1D are provided on the underside of the
shoulder 1 between the stem 100 and the head 1A, the
radiussed recesses 24 on the plate 2 would have to be
deeper. If the tangs 1C on the underside of the shoulder 1
were omitted, the apertures 26 in the plate 2 could be made
5 smaller, but would still be present to allow formation of
the underside of tabs 27 during moulding of the sealing
plate 2.
The shoulder 1 is held in place and positioned in the
mould by means of a mechanism which pulls on the head 1A
10 that protrudes through the bottom of the mould. The
projections 120 on the shoulder 1 serve to reduce the
amount of this pulling force which is applied to the
sealing plate, which might otherwise distort. The walls of
the projections 25 serve to prevent sideways movement of
15 the sealing plate and shoulder during sleeper manufacture
by acting against the edges of the aperture in the mould
pocket.
The second major face 21 of the plate 2, which forms
the underside of the plate, is formed with a plurality of
20 intersecting sibs 28 which define numerous rebates 29.
When the plate is set into the top surface of a concrete
sleeper, these rebates 29, and the underside of the
projections 25 which are also hollow, are filled with
concrete, providing additional strength to the plate 2, and
25 thereby reducing the amount of material, and hence cost,
required to make the plate 2.
A railway rail fastening assembly employing the
elements described above will now be described with
reference to Figures 3A to 3F. The railway rail fastening
30 assembly of Figures 3A to 3F, for fastening a railway rail
5, comprises a shoulder 1 as described with reference to
Figs. 2A to 2G, a rail fastening clip 3, a sealing plate 2
embodying the first aspect of the present invention and a
rail pad 4. It will be appreciated that, although not
shown in Figures 3A to 3F, when in use the rail is fastened
on both sides of the rail head by such an assembly and that
the stem 1B and tangs 1C are embedded in the concrete
5 sleeper 6. The sealing plate 2 is also embedded in the
concrete sleeper 6, such that the top face of sealing plate
2 is flush with the upper surface of the sleeper 6. As
shown in Figures 3A/3B the clip 3 may be driven into the
shoulder 1 by introducing the chamfered free ends A, B of
10 clip legs 31, 37 into the gaps between the top surfaces 25a
of the clip seat projections 25 on the sealing plate 2 and
the first projection 110A on the outer surface of the walls
10 of the shoulder 1, and inserting toe portion 34 of the
clip 3, bearing a toe insulator 34a, into the space between
15 the inner surfaces of the walls 10 of the shoulder 1, such
that the toe 34 of the clip 3, through the toe insulator
34a, bears on the ramp 140 of the shoulder 1 and the
projections 110A are located within detents 38 in the clip
legs 31, 37, with the projection llOA contacting the rear
20 face of the detent 38. This position is known as the "preassembly"
or "parlced" position, in which the clip does not
bear on the rail 5, but overlies she1.f 47 of side post
insulator portion 46 of pad 4. Downwardly-facing parts of
the legs 31, 37 rest on the top surfaces 25a of the clip
25 seat projections 25.
As shown in Figures 3C and 3D, the clip 3 can be driven
from the pre-assembly position (first operative position)
into a second operative position in which the toe portion
34 of the clip 3 bears on the foot of the rail 5, the
30 second projections 110B on the walls 10 engage the detents
38 of legs 31, 37 of the clip 3 and second and sixth
portions 32, 36 (heel portions) of the clip 3 bear on the
top surfaces 25a of the clip seat projections 25. The clip
overlies the shelf 47 of the side post insulator portion 46
of the rail pad 4. The clip can be withdrawn Erom this
position back into the pre-assembly position, if required
in order to remove or work on the rail, or further back
5 into the "insulator-change" position in which the front
face of the detent 38 contacts the projection llOA and the
clip 3 does not overlie the shelf 47 of the sidepost
insulator portion 46 of pad 4.
As the clip 3 is installed, the toe 34 of the clip 3 is
10 driven upwards by the ramp 140 in the centre of the
shoulder 1, and the legs 31, 37 are driven down, thereby
splitting the clip open. This makes it possible to make the
assembly a little lower than would otherwise be possible.
We claim:
1. A method of manufacturing a concrete sleeper with at least one embedded
rail clip anchoring device (1) of the type having a head (IA) for retaining a rail clip (3)
and a stem (100) extending from the underside of the head (IA), in which method
the floor of a mould, from which the sleeper is to be formed, is provided with an
aperture, the head (IA) of an anchoring device (1) is inserted through the aperture
such that the head (IA) of the device (1) extends out of the mould and the stem
(100) of the device (1) is located within the mould, and concrete is introduced into
the mould, characterised in that before the concrete is introduced into the mould the
aperture is sealed off around its edges and around the underside of the head (IA) of
the anchoring device (1) by placing a sealing plate (2) over the aperture on the floor
of the mould, the plate (2) overlapping and sealing around the edges of the aperture
other than where the anchoring device (1) is located and having a mating interface
with the anchoring device ( I ) such that a seal is formed therewith.
2. A method as claimed in claim 1, wherein before the sealing plate (2) is
introduced into the mould it is connected to the anchoring device (1) so as to extend
over the underside of the head (IA), the sealing plate (2) being introduced into the
mould together with the anchor~ngd evice (1) and located over the aperture when the
head (IA) is inserted through the aperture.
3. A method as claimed in claim 1 or 2, wherein, when the aperture is
substant~ally rectangular and a first face of the head (IA) of the anchoring device (1)
abuts one side of the aperture, the sealing plate (2) is shaped so as to mate with a
second face of the head (IA) of the anchoring device (I), opposite to said first face,
and to overlap the edges of the aperture on the other three sides thereof.
4. A method as claimed in claim 3, wherein the edge (22a) of the sealing plate
(2) which mates with the second face of the head (IA) is bevelled so as to match
bevelling on the said second face.
5. A method as claimed in claim I, 2, 3 or 4, employing a sealing plate (2) as
claimed in any one of claims 1 to 9 or a sealing plate and anchoring device
combination as claimed in any one of claims 10 to 15.