SWITCH FOR GROOVED RAILS

AIGUILLAGE POUR RAILS CREUX

English Abstract

The switch is constituted by a profiled cradle
forming the housing of a movable tongue-rail (18) for
deviation and constituted by a profiled body (20)
constructed by machining by removal of swarf. In order
to reduce the machining waste and to improve the
reliability of movement of the tongue-rail, the body (20)
is bolted between a stock-rail (22) and an opposite rail
(24), both deprived of their adjacent foot over the
entire length of the body (20) and the upper surface of
the body (20) supporting the movable part of the tongue-
rail (18) is profiled so as to present flat pillow blocks
(28) for support of the tongue-rail (18) alternating with
recesses (30) machined in the body (20).

Claims

Claims:
1. A switch for a railway having grooved rails, the switch comprising: a
movable switching tongue-rail (18), a profiled cradle forming a housing for
the
movable tongue-rail (18) and having rolling and guiding surfaces permitting
switching movement of the tongue-rail, the cradle comprising a profiled body
(20)
formed by machining, characterised in that the profiled body (20) is bolted
between a stock-rail (22) and an opposite rail (24), bath of which have a
foot,
opposing portions of which are absent over the entire length of the profiled
body
(20), in that the stock-rail (22) has no groove (36) over the length of
mobility of
the tongue-rail (18), and in that the upper surface of the profiled body (20)
supporting the movable tongue-rail (18) is profiled so as to present flat
pillow
blocks (28) for support of the tongue-rail (18) alternating with recesses (30)
machined in the profiled body (20).
2. Switch according to Claim 1, characterized in that the opposite rail (24)
has no groove over the entire length of the switch.
3. Switch according to Claim 1, characterized in that the area of the recesses
(30) is greater than that of the pillow blocks (28).

Description

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SWrTCH FOR GROOVEn RA.'L:LS
The present invention relates to a switch for
grooved rails of rail traffic, constituted by a profiled
cradle forming the housing of a movable 'tongue-rail for
deviation, and also the rolling and guiding surfaces
permitting the movement of the tongue-rail, the cradle
being constituted by a profiled body produced by
machining by removal of swarf.
The invention relates more particularly, without
being limited thereto, to a switch for the tracks of urban
transport systems or of port i.nstalla~tions, whose rails
are buried in the surface of t;he road network.
These switches were, hitherto, generally
constructed by assembling various components, of
different quality and shape, manufactured to measure,
either by, casting or by machining, and assembled
manually, usually by welding.
Patent LU-87,503 proposes a new process for
production of switches of the type described above, which
is performed entirely by machining exclusively by removal
of swarf. This process for production of switches has many
advantages; these include the possibility of automated
production under programmed control, the possibility of
eliminating welds and the fact of not having to carry a
large stock of spare parts or to be dependent on the
supply of these parts.
In order to reduce machining time and waste,
Patent LU-87,721 proposes to retain the stock-rail and
to associate it, aftex removal of the inner part of its
foot, by bolting, with the machined body.
The purpose of the present invention is to
provide an improved , semi-assembled and semi-machined
switch , in which the non-machined parts are standard
parts and which permit a more reliable movement of the
tongue-rail.
In order. to attain this objective, the invention
proposes a switch of the kind described in the preamble,
which is essentially characterised in that the body is

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bolted between a stock-rail and an opposite rail, both
deprived of their adjacent foot over the entire length of
the body, in that the stock-rail is deprived of its
groove over the length of mobility of the tongue-rail and
in that the upper surface of the body supporting the
movable part of the tongue-rail is profiled so as to
present flat pillow blocks for support of the tongue-rail
alternating with recesses machined in the body.
The parts most vulnerable to wear are the stock
rail and the opposite rail. Given that these parts are
standard parts, they are always available and can be
replaced individually after wear, since they are
assembled by bolting to the machined body. Such an
assembly also permits a better compensation of the
machining tolerances. Compared with monobloc machined
switches, the switches proposed by the present invention
additionally make it possible to reduce the machining
time and waste.
The risks of the movement of the tongue-rail
being impeded by foreign bodies, stones for example, are
reduced owing to the special design of the machined body,
given that these foreign bodies can accumulate at the
bottom of the recesses, where they do not hinder the
movement of the tongue-rail.
Other features and characteristics of the
invention will emerge from the detailed description of an
advantageous embodiment, set out below by way of
illustration, with reference to the accompanying figures
in which:
Figure 1 shows a diagrammatic plan view of a
switch ;
Figures 2. ~0 6 show cross-sections al~ng
sectional planes of Figure 1 defined respectively by A,
B, C, D and E and Figure 7 gives a perspective view of
the part of the machined body supporting the movable part
of the tongue-rail.
Figuxe 1 shows a pair of rails 10, 12 which are
extended by a switchl4 designed to guide a train, either

on the pair of rails 10a, 12a o.r on the pair of rails
10b, 12b. The switch operates in conventional manner; only
the production process and, consequently, the profile
of the parts used differ from the state of the art. This
is illustrated by the different cross-sections as shown
in Figures 2 to 6.
Figure 2 shows a cross-section of the switch at
'the tip of a tongue-rail 18. The housing of 'the tongue-
rail 18 is delimited by a body 20 supporting the tongue-
rail 18, a stock-rail 22 and an opposite rail 24 which
are deprived of the inner part: of their foot and which
are bolted to the body 20 with the aid of bolts 26 as
shown in Figure 3.
The body 20 is produced by machining, preferably,
by automatic milling under programmed control. According
to one of the features of the present invention, the part
of the body 20 supporting the movable part of the tongue
rail 18 is, as shown in Figure 7, in the form of a
succession of pillow blocks 28 and of recesses 30
separating the pillow blocks 28. Fach pillow block 28
comprises a perforation 32 permitting the passage of the
bolts 26. The purpose of these recesses 30 is to collect
foreign bodies, such as stones and gravel or the like
which, without the presence of the recesses, could hinder
the correct operation of the tongue--rail 18. To achieve
optimum effect, the area of the recesses 30 is,
preferably, greater than the area of the pillow blocks
28. Of course, the dirt which can accumulate in the
recesses 30 must be removed by regular cleaning. To this
end, the body 20 comprises a longitudinal machinsd
channel 34 allowing cleaning water and rain water to run
off .
The stock-rail 22 may be formed by the rail 10,
10a or the rail 12, 12b of the existing track or by a
grooved rail welded to these rails. Over the length of
mobility of the tongue-rail 18 the stock-rail 22 must be
deprived of 9.ts groove so as to permit operation of the
switch. Beyond the zone of activity of the tongue-.rail

4
18 the stack-rail 22 must, of course, possess its groove
36 as shown in Figure 4 and the following figures.
Although not compulsory, but desirable, if only
to facilitate access to the bolt 26, the rail 24 may also
be deprived of its groove over the entire length of the
points. As shown in the figures, the two rails 22 and 24
retain, over the entire length, the outer part of their
foot, and this contributes to a better symmetry and to
integration with standard components.
The reference 44 denoi:es an electrical heating
resistor. This is held in place by profiled washers 38
associated with the mounting k>olts 26. In Figure 2 the
two rails 22 and 2.4 as well as the tongue-rail 18 are
pierced horizontally in order to permit installation of
the means, not shown, for moving the 'tongue-rail 18.
The invention therefore makes it possible to
reduce a not inconsiderable part of the machining
necessary for the production of a monobloc rail, by
taking advantage of the existence of the stock-rail 22
and of the opposite rail 24. These two rails are standard
sections from which it is sufficient to remove, by
machining, the inner part of the foot and of the groove.
These two parts may also be replaced individually and
separately, which is all the more advantageous as these
are the parts most vulnerable to wear.
Figures 4, 5 and 6 show cross-sections through
the rear part of the switch where the machined body 20
has a ridge 20a widening progressively and rising up to
the upper level of the switch. This ridge 20a ensures the
separation of the stock-rail 22 and the tongue-rail l8.
2n the embodiment shown, the heel of the tongue
rail 18 is secured in the body 20 by means of a key 40.
The latter is, in its turn, wedged with the aid of a bolt
42 anchored in the body 20. In order to permit tightening
of the bolt 42, the head of the rail 24 is removed at
this place (see Figure 4).
Figure 6 shows a cross-section at the end of the
switch at the place where the tongue-rail 18 and the rail

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10b join.
As in known switches,it is possible to subject the
body 20, after it has been machined, to a heat treatment
or localised hardening so as to produce a surface
hardening of the parts most exposed to stresses. Tt is
also possible to perform surface refillings by welding
so as to increase the strength locally.

Representative Drawing