Note: Descriptions are shown in the official language in which they were submitted.
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RAILWAY RAIL-FASTENI G CLIP
The present invention relates to a railway
rail-fastening clip.
CA-1,037929 discloses a rail clip, proposed by the
present applicants, which has become known as an
"e-clip", because when viewed from a particular
direction it has in plan the shape of a letter "e".
Such an e-clip is formed by bending a metal rod, of
length less than eigh-teen times its thickness, so as to
have, proceeding from one end of the rod to the other,
a first portion which is substantially straight, the
one end of the rod constitutin~ a free end of the first
portion, a second portion which is a reverse bend, a
third portion, a fourth portion which is another
reverse bend, and a fifth portion, the construction of
tha clip being such that it can be placed in a position
in which the first portion is horizontal and the third
and fifth portions, when viewed from above, appear to
lie on opposite sides of the first portion. When the
clip is in use, the first portion, or centre leg, of
the clip is located inside a corresponding passageway
in a rail shoulder, secured to the rail foundation
alongside the rail, and the fifth portion of the clip
bears down on a flange of the rail itself, or, more
commonly, on an insulator between the clip and the
rail.
: The e-clip was introduced by the applicants as an
improvement over one of their prior rail clips
disclosed in CA-612,743, known as a PR-clip, and one
way in which it differed from the PR-clip was that the
centre leg of the e-clip was shorter than that of the
PR-clip, enabling the e-clip to be made of less
material and accordingly at lower cost. However, in
shortening the centre leg, the e-clip lost an advantage
provided by the centre leg of the PR-clip, namely that
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the PR-clip can be positioned accurately simply by
driving the clip until the free end of the centre leg
thereof abuts the closed end of the passageway in the
rail shoulder.
According to a first aspect of the present
invention there is provided a clip for fastening a
railway rail to a rail foundation, which clip is made
of a rod of resilient materia:L such that it has at
least one bent portion of which the axial cross-
sectional area is greater than that of the remainder of
the clip.
Such clip may have at least one bent portion of
which the axial cross-sectional area is the same as
comparable prior art clips, whereas other portions of
the clip are of reduced axial cross-sectional area
thereby enabling a clip embodying the first aspect of
~ the present invention to be made of less material than
: a comparable prior art clip, whilst maintaining the
strength of the bent portion which is subject to higher
stress than the other portions of the clip.
; Preferably, the or each bent portion is a portion
of the clip to which an external force is applied so as
to drive the clip into an associated clip anchoring
device.
A first embodiment of the clip is approximately
M-shaped in plan and has, proceeding from one end of
the rod to the other, a substantially straight first
part, a bent second part, a third part, a bent fourth
part, a fifth part, a bent sixth part, and a
3~ substantially straight seventh part, th0 axial cross-
sectional area of the said second and sixth parts being
greater than that of the other parts of the clip.
A second embodiment of the clip comprises,
proceeding along the rod from one end thereof to the
other, a firs-t portion which is substantially straight,
the said one end of the rod constituting a free end of
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the said first portion, a second portion which is a
reverse bend, a third portion, a fourth portion which
is another reverse bend, and a fifth portion, the
construction of the clip being such that it can be
placed in a position in which a longitudinal axis of
the first portion extends horixontally and the third
and fii`th portions, when viewed from above, appear to
lie on opposite sides of the said firs-t portion,
wherein the axial cross-section of more than a tenth of
the lsngth of the said first portion of the clip is
smaller in area than the axial cross-section of at
least a region of the said second portion of the clip.
Preferably, the area of the axial cross~section is
substantiall~ uniform along the length of the said
second portion of the clip.
Desirably, the axial cross-section of at least a
part of the said first portion decreases progressively
in area, proceeding from a first end of that part to a
second end thereof that is closest to said free end of
the said first portion, such that the said second end
has a smaller axial cross-sectional area than a region
of the said second portion adjacent to the said first
portion. Preferably, said part constitutes
approximately 30% of the length of the said first
portion.
Desirably, in such a case, the said second end of
the said part is constituted by said free end of the
said first portion.
Preferably, so as achieve accurate location of the
first portion of the clip according to the second
embodiment more easily, whilst retaining the advantage
of requiring less material, the said first portion
extends at least partially under the said fourth
portion, as viewed from above when the clip is in the
said position. In particular, the said metal rod,
before being formed into a clip having such a centre
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leg, may be of substantially uniform axial cross-
sectional area and of length less than 18 times its
thickness.
Desirably, the axial cross-section of the said
first portion decreases progressively in area along its
entire length, such that the area of the axial cross-
section of the first portion is smallest at the said
free end thereof.
In such circumstances, it is preferable that the
first portion is such that, when said first portion is
located within a passageway of an anchoring device for
retaining the clip, that part of its surface which is
uppermost extends substantially parallel to an upper
internal surface of said passa~eway.
Alternatively, the axial cross-section of at least
a part of one or more of the said third, fourth and
fifth portions desirably undergoes a progressive
reduction in area, proceeding from a first end of that
part to a second end thereof that is closest to a free
end of the said fifth portion, such that the said
second end has a smaller a~ial cross-sectional area
than a region of the said second portion adjacent to
the said third portion.
Desirably, in such a case, the axial
~5 cross-section of at least a part of one of the said
third, fourth and fifth portions undergoes such a
reduction in area, the axial cross-section of the
others of the said third, fourth and fifth portions
being of substantially uniform area along the
respective lengths of those portions.
According to a second aspect of the present
invention there is provided a method of manufacturing a
clip according to the second embodiment of the ~irst
aspect of the present invention, wherein before, after
or during a process of bending a metal rod to form the
said first to fifth portions of the clip, the axial
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cross-section of a part of that portion of the rod
~hich is to form said first portion is reduced in area
as compared to another portion of the rod which is to
form said second portion, the reduction in area being
achieved without loss of material from the rod and said
part constituting more than a tenth of -the leng~h of
said first portion of the finished clip.
Preferably, said reduction in area is achieved by
rolling the part concerned. Alternatively, said
reduction in area may be achieved by drawing out the
part concerned thereby to extend and taper it.
According to a third aspect of the present
invention there is provided an assembl~ for fas-tening a
railway rail to a rail foundation, comprising a clip
according to the second embodiment of the first aspect
of the present invention and an anchoring device,
secured to the said rail foundation alongside the rail,
having a passageway therein, one end of which is
closed, in which the said first portion of the clip is
located when the assembly is in use, wherein the said
free end of the first portion abuts the said closed end
of the passageway.
Preferably, when the uppermost surace of the
first portion extends parallel to the upper internal
surface of the passageway, that part abuts the said
upper internal surface, thereby improving the
resistance of the clip to pull-out from the anchoring
device.
According to a fourth aspect of the present
invention there is provided a method of installing a
clip according to the second embodiment of the first
aspect of the present invention in an anchoring device
having a passageway with a closed end, wherein the said
first portion of the clip is driven into the said
passageway until the said free end of the first portion
abuts the c:Losed end of the passageway.
3 ~ 3
It should be noted that, whilst it: has been known
previously to chamfer the free end of the centre leg,
so as to round off any burrs there might be around that
free end and so prevent any difficulties such burrs
might otherwise have caused during insertion of the
centre leg into the passageway of the rail shoulder,
only a very small length of the. centre leg was ever so
chamfered. Typically, a 45 chamfer extending 3mm from
the end of the centre leg of a clip is applied,
although chamfers of up to 5mm have been known.
It has been known in "e-clip" type rail clips to
flatten the fifth portion of -the clip during
manufacture, this being the portion that commonly bears
down on a rail flange, so as to increase the area of
the surface that is in contact with the flange or an
interposed insulator. However, this does not enable a
sa~ing in material to be made over e-clips that have
not been so formed, nor does it result in a larger
axial cross-sectional area of the flattened portion.
Reference will now be made, by way of example, to
the accompanying drawings, in which:-
Figure 1 shows a side view of a clip embodying the
first aspect of the present invention;
Figure 2 shows a plan view of the clip of Figure
1;
Figure 3 shows a side view of another clip
embodying the first aspect of the present invention;
Figures 4 and 5 show respective plan and front
elevational views of the clip of Figure 3;
Figure 6 shows a side view of a further clip
embodying the first aspect of the present invention;
and
Figures 7 and 8 show respective plan and front
elevational views of the clip of Figure 6; and
Figure ga shows a side view of yet another clip
embodying the first aspect of the present invention and
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Figure 9b shows a plan view of the clip concerned in a
rail fastening assembly; and
Figures lOa, lOb and lOc show respective plan,
side and rear views of a still further clip embodying
the first aspect of the present invention in a rail
fastening assembly.
The clip shown in Figures 1 and 2 is made o a
metal rod. The clip comprises, proceeding along the
rod from one end thereof to the other, a first portion,
or centre leg, 1 which is substantially straight, a
bent second portion 2, a third portion 3, a bent fourth
portion 4, and a fifth portion 5. When the clip is
viewed from above, as shown in Figure 2, the third
portion 3 and fifth portion 5 lie respectively on
opposite sides of the first portion 1. As illustrated
in Figure 1, the fourth portion 4 has a rising part 4a
and a falling part 4b, such that the fourth portion 4
is substantially arched. The second portion also has a
rising part 2a and a falling p~rt 2b, but the rising
part 2a is inclined, with respect to the longitudinal
axis of the said first portion l, by a comparatively
small angle which is less than 45. The underside of
the fifth portion 5 is provided with a substantially
flat surface 5a which, when the clip is in use, bears
downwardly upon the flange of a rail or, more commonly,
upon an insulator provided between the clip and the
rail.
The centre leg 1 has a part la in the vicinity of
a free end lb thereof, which is tapered, i.e. the axial
cross-section of that part progressively decreases in
area, towards the free end, and extends partially under
the fourth portion 4. Not only does such tapering on
the centre leg of the clip permit that portion to be
inserted more easily into a passageway in a rail
shouldert it also achieves lengthening of the centre
leg as compared to that of the afore-mentioned e-clip,
2~732~
without having to use a longer rod. Thus, as with the
e-clip, the clip of Figs. 1 and 2 may be formed of a
metal rod which is of substantially uniform thickness
and of length less than eighteen times its thickness.
Such lengthening of the centre leg enables the clip to
be installed in a rail shoulder more accurately,
particularly by automatic clip-driving machines, as the
clip can be driven into the passageway until the free
end of the lengthened centre lleg abuts the closed end
of the passageway. Thus, such a clip, which embodies
the first aspect of the present invention, can combine
the advantages of easier and more accurate installation
and cheaper cost as compared to prior art clips.
The centre leg of the clip may be tapered by
drawing out one end of the metal rod, which is to form
the clip, while it is still red hot, thereby to e~tend
and taper that portion of the rod.
Alternatively, the reduction in area of the axial
cross-section may be achieved by rolling part of the
metal rod. Such reduction can achieve, for example, a
ten millimetre extension of the centre leg, as compared
to that of an "e-clip".
Although it is particularly advantageous to reduce
the axial cross-sectional area of the free end lb of
the centre leg 1 in such a way as to lengthen that
centre leg 1 as compared to conventional e-clips,
simply reducing the axial cross-sectional area of any
part of the centre leg 1 without achieving an increase
in length thereof as compared to conventional e-clips
can result in a significant decrease in the amount of
material used, and hence also in the cost of making the
clip .
In this respect, the applicants believe that it
would be particularly desirable to reduce the axial
cross-sectional area of the whole length of the centre
leg 1. Clips having such centre legs l are shown in
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Figs. 3 to ~ and 6 to 8, but, apart from the feature
described below with reference to those Figures, -those
clips are otherwise substantially the same as the clip
of Figures 1 and 2.
In addition to the centre leg, it may be desirable
to reduce the axial cross-sectional area o~ at least
part of any or all of the third, fourth and fifth
portions of such clips, but not the second por-tion
thereof since this portion o~ the clips is subject to
higher stress than the other portions.
With f~rther reference to the clips of Figures 3
to 5 and 6 to 8, as can be seen in Figures 3 and 6
particularly each of these clips has a tapered centre
leg 1 which is tilted such that an uppermost part lc
thereof extends in such a direction that, when the
centre leg 1 is within a passageway of an anchoring
device, the uppermost part lc lies parallel to an upper
internal surface, i.e. the roof, of the passageway.
Installation of a rail-fastening clip into an anchoring
device forces the uppermost part of the centre leg 1 of
the clip against the roof of the passageway. Thus, the
uppermost par-t lc of the centre leg 1 of the clips of
Fi~ures 3 to 5 and 6 to 8 abuts the roof of the
passageway along its entire length, thereby increasing
the resistance of such clips to pull-out from the
anchoring device.
As with prior art clips, it may be desirable, as
illustrated in Figures 3 to 8, to form a chamfer ld at
the free end of the centre leg l, so as to remove burrs
which might otherwise have hampered insertion of the
clipo
The clips shown in Figures 1 to 8 have features in
common with the afore-mentioned "e-clip". However, the
present invention may also be applied to a clip which
is not o~ the "e-clip" type.
In this regard, reference will now be made to the
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clips shown in Figures 9a and 9b and Figures lOa to
lOc .
The clip in each case is approximately M-shaped in
plan and is made of a rod of resilient material bent so
as to have, proceeding from one Pnd O f the rod to the
other, a substantially straight first part 11, a bent
second part 12, a substantiall.y straight third part 13,
a bent fourth part 1~ which bears on a rail when the
clip is in use, a substantiall.y straight fifth part 15,
a bent sixth part 16, and a substantially straight
seventh part 17.
The clip of Figures 9a and 9b ha~ third, fourth
and fifth parts 13, 14, 15 which have respective
longitudinal axes lying substantially in a first plane
and first, second, sixth and seventh parts 11, 12, 16,
17 which have respective longitudinal axes lying
substantially in a second plane, the first plane b~ing
inclined with respect to the second plane (Figure 9a,
dotted line) except when the clip is bearing on a rail
when the first and sPcond planes are substantially
coincident (Figur~ 9a, unbroken line).
The longitudinal axes of the second and sixth
parts 12, 16 of the clip of Figures lOa to lOc lie
substantially in respective planes which are inclined
with respect to a plane containing the first and
seventh parts 11, 17, the third and fifth parts 13, 15
lying in a further plane which is above the plane
:: containing the first and seventh parts 11, 17.
In each case, the second and sixth parts 12, 16,
denoted by the letters a-b in Figures 9a and 9b and A-
B-C in Figures lOa to lOc, are thicker in cross-section
than the other parts of the clip, since the parts 12
and 16 are subject to greater stress than the remainder
of the clip and mu~t be of a particular thickness,
whereas the other parts need not be so thick.
Thus, the invention can be applied to railway rail
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fastening cllps made from a rod of resilient material
not only of the "e-clip" type, but also of any other
type where a reduction in the material required to make
the clip, without consequent weakening of the clip in
5 regions thereof sub~ ec t to the highest stress, would be
advantageous .
