[0001] The present invention concerns a switching machine for switching the position of
railway tracks, the switching machine being of the type comprising:
- a frame, intended to be fixed relatively to a pair of stock rails of a railroad switch,
- a throw bar translatable relatively to the frame along a transverse direction to throw
a pair of inner rails of the railroad switch, located between the stock rails, from
a normal track position to a reverse track position, and from the reverse track position
to the normal track position,
- a point detector bar, translatable relatively to the frame along the transverse direction
between a normal detection position intended to correspond to the normal track position
of the inner rails and a reverse detection position intended to correspond to the
reverse track position of the inner rails,
- an indication contact assembly, fixed relatively to the frame, comprising at least
one switch,
- at least one detector bar follower, movable relatively to the frame between a proximal
position, in which the detector bar follower acts on the switch, and a distal position,
in which the detector bar follower is away from the switch, the detector bar follower
being adapted to follow displacement of the point detector bar in such a manner that,
when the point detector bar is in one of its normal and reverse detection positions,
the detector bar follower is in a first position among the proximal and distal positions
and, when the point detector bar is in an intermediary position between its normal
and reverse detection positions, the detector bar follower is in the second position
among the proximal and distal positions,
- an inhibiting element jointly movable with the detector bar follower between a primary
position when the detector bar follower is in its first position and a secondary position
when the detector bar follower is in its second position,
- a cam bar having a kinematic connection with the throw bar in such a manner that the
cam bar and the throw bar are jointly translatable relatively to the frame, the cam
bar comprising a tongue portion and being translatable relatively to the frame along
a longitudinal direction (X) between an unlock position in which the tongue portion
is able to be in contact with a stop of the inhibiting element, preventing the inhibiting
element from reaching its secondary position, and a lock position in which the tongue
portion is away from the stop, allowing displacement of the inhibiting element between
its primary and secondary positions.
[0002] Such switching machines are known and are generally motor driven. An example of such
a switching machine is the GRANDMASTER 4000 Switch Machine of ALSTOM.
[0003] In the known switching machines, there are generally two detector bar followers,
each one being rotatable relatively to the frame around a respective rotation axis
and being adapted to act on a respective switch of the indication contact assembly
when it is in its proximal position, the detector bar followers comprising a first
detector bar follower which is adapted to be in its second position when the point
detector bar is in its normal detection position and a second detector bar follower
which is adapted to be in its second position when the point detector bar is in its
reverse detection position.
[0004] This structure allows the switching machine to detect when the inner rails are in
their normal position, in their reverse position, and in an intermediate position
between their normal and reverse position. Indeed, when the inner rails are in their
normal or reverse position, only one of the switches of the indication assembly will
be activated by the detector bar followers; this will inform the switching machine
that the railroad switch is in a safe configuration, and the switching machine will
emit a signal to inform the trains circulating on the railroad that they are allowed
to cross the railroad switch. Furthermore, depending on which switch is activated,
the switching machine will be able to conclude if the rails are either in their normal
or reverse position. When the inner rails are in an intermediate position however,
either both or none of the switches will be activated by the detector bar followers,
thus providing the switching machine with the information that the railroad switch
is not in a safe configuration. As a result, the switching machine will emit a signal
to inform the trains circulating on the railroad that they shall not go through the
railroad switch.
[0005] An additional element of the known switching machines is the lock bar, which is intended
to lock the inner rails after the throw bar has switched them into position. To that
end, the lock bar has notches formed therein and intended to receive a lock lug of
the cam bar when the cam bar is in its lock position. When the inner rails are not
properly positioned at the end of the movement of the throw bar, none of the notches
formed in the lock bar is aligned with the cam bar, so that the lock lug cannot be
received therein; the cam bar can therefore not reach its lock position and release
the inhibiting elements. In such a case, the inhibiting elements block the detector
bar followers in their first position so that none of the detector bar followers can
move towards its second position, even if the point detector bar is in its normal
or reverse detection position. As a result, either both or none of the switches will
be activated by the detector bar followers, thus providing the switching machine with
the information that the railroad switch is not in a safe configuration, and the switching
machine will emit a signal to inform the trains circulating on the railroad that they
shall not go through the railroad switch.
[0006] As one can easily understand from the foregoing, detection by the switching machine
of safe and unsafe configurations of the railroad switch depends on the respective
positioning of the point detector bar and of the lock bar, a safe configuration being
detected only in the case when both the point detector bar and the lock bar respect
a precise positioning relatively to the frame and relatively to each other.
[0007] In order to maintain proper operation of the switching machine, monthly inspection
of the point detection system is required. Since normal operation of the switching
machine involves all components moving together, it is necessary to isolate desired
variables for this test. To do this, traditionally the lock bar is forced out of proper
adjustment or disconnected from the rails altogether such that the switching machine
can indicate a safe configuration of the railroad switch even with an obstruction
in the rail, when normal operation of the lock bar would have prevented such an indication
to occur. The railroad switch is then manually thrown from one position to the next
to determine that the contacts are appropriately adjusted and that the point detector
bar is still properly driving the indication. Everything must then be replaced to
its original state before maintainers can reinstate the railroad switch and allow
trains through.
[0008] To disconnect or readjust the lock bar requires numerous large tools and increases
the time that maintainers are on the track. This also increases the time that trains
are disallowed through that section of track, and maintainers often have to wait for
long periods of time before the track is scheduled to be clear long enough for their
work. Furthermore, failure to properly restore the adjustment of all components could
cause a failure of the switching machine, allowing false indications and potentially
causing the derailment of a passing train.
[0009] Accordingly, it is a primary object of the present invention to provide a means of
disconnecting the function of the lock bar in the switching machine without the need
to readjust it.
[0010] Another object of the present invention is to decrease the time it takes maintainers
to prepare for the Point Detector Integrity Test.
[0011] A further object of the present invention is to decrease the number of tools required
for maintainers to prepare for the Point Detector Integrity Test.
[0012] Still another object of the present invention is to ensure the machine cannot be
remotely operated while the Point Detector Integrity Test is occurring.
[0013] A yet further object of the present invention is to ensure the proper adjustment
of all components in the switching machine is returned before the machine is operable
again.
[0014] To this end, the invention consists in a switching machine of the aforementioned
type, wherein the inhibiting element comprises a main body relatively to which the
stop is vertically translatable between an active position, in which the stop is in
contact with the tongue portion of the cam bar when the cam bar is in the unlock position,
and a passive position, in which the stop is away from the tongue portion of the cam
bar when the cam bar is in the unlock position.
[0015] According to particular embodiments of the invention, the switching machine further
comprises one or several of the following features, considered or alone or according
to any technically possible combination:
- the inhibiting element comprises a biasing member biasing the stop toward its active
position;
- the switching machine comprises a latch assembly to latch the stop in its passive
position;
- the stop comprises a vertical shaft with a shaft body extending through a hole formed
in the main body and, on top of the shaft body, a shaft head with a larger diameter
than the diameter of the shaft body, and the switching machine comprises an actuation
device to displace the stop between its active and passive positions, said actuation
device comprising a plate assembly which is vertically translatable relatively to
the frame, said plate assembly including a plate having a slot formed therein and
through which the shaft body extends, said slot having a shape that follows the path
of the shaft when the inhibiting element is displaced between its primary and secondary
positions;
- the latch assembly comprises a latch with a front face and a protrusion protruding
from said front face, said latch being rotatable relatively to the frame around a
horizontal axis between a latching position, in which the protrusion extends within
a displacement region of the plate assembly, and a liberation position, in which the
protrusion is out of the displacement region of the plate assembly, the position of
the plate assembly when the stop is in its passive position being above the position
of the protrusion when the latch is in its latching position, and the latch assembly
further comprises a biasing element biasing the latch toward its latching position;
- the switching machine comprises a safety circuit to detect when the stop is in its
passive position, said safety circuit comprising at least two stationary contacts
and at least one mobile contact mounted on the plate assembly in a manner that, when
the stop is in one of its passive and active positions, the mobile contact bridges
the two stationary contacts, thus closing the safety circuit and, when the stop is
in the other one of its passive and active positions, the mobile contact is away from
the stationary contacts, thus opening the safety circuit;
- the switching machine comprises two detector bar followers, each one being adapted
to act on a respective switch of the indication contact assembly when it is in its
proximal position, the detector bar followers comprising a first detector bar follower
which is adapted to be in its second position when the point detector bar is in its
normal detection position and a second detector bar follower which is adapted to be
in its second position when the point detector bar is in its reverse detection position;
- the stop of the inhibiting element of each detector bar follower is closer to the
inhibiting element of the other detector bar follower when both inhibiting elements
are in their secondary position than when both inhibiting elements are in their primary
position, and the tongue portion of the cam bar has a median longitudinal axis which
extends between both inhibiting elements;
- the point detector bar has a cylindrical surface in which a notch is formed, the detector
bar follower is rotatable relatively to the frame around a vertical rotation axis
between its first and second positions and has a follower part adapted for contacting
the point detector bar in such a manner that, when the follower part is in contact
with the cylindrical surface of the point detector bar, the detector bar follower
is in its first position and, when the follower part is received in the notch, the
detector bar follower is in its second position, the main body of the inhibiting element
is rotatable relatively to the frame around a vertical pivoting axis, and the inhibiting
element comprises a connecting rod connecting the detector bar follower to the main
body; and
- the detector bar followers have a common biasing device comprising at least one spring
having a first end attached to the main body of the inhibiting element of the first
detector bar follower and a second end attached to the main body of the inhibiting
element of the second detector bar follower, said common biasing device biasing both
detector bar followers toward their second position;
[0016] These and other features and advantages of the invention will be understood by reference
to the following description in conjunction with the annexed drawings, wherein:
- Figure 1 is a plan view of a railroad switch connected to a switching machine according
to the invention,
- Figure 2 is a plan view of a point detection system of the switching machine of Figure
1, wherein some components have been omitted to show hidden details,
- Figure 3 is a cross-section view taken along line III-III of Figure 2,
- Figure 4 is a perspective view of some components of the point detection system of
Figure 2, showing components which had been omitted in Figure 2, an inhibiting device
of the point detection system being shown in an active configuration,
- Figure 5 is a plan view showing the cam bar and the components of Figure 4 seen from
above,
- Figure 6 is a cross-section view of the components of Figure 5 taken along line VI-VI
of Figure 5,
- Figure 7 is a perspective view of a portion of the inhibiting device of the point
detection system of Figure 2,
- Figure 8 is a partially exploded perspective view of a plate assembly of the point
detection system of Figure 2, and
- Figure 9 is a perspective view of a latch assembly of the point detection system of
Figure 2.
[0017] The railroad switch 10 shown in Figure 1 has stock rails 12A, 12B and inner rails
14A, 14B. A front rod 16 and a second rod 18 interconnect the inner rails 14A, 14B.
The inner rails 14A, 14B are movable relatively to the stock rails 12A, 12B between
a reverse position, in which a first inner rail 14A is in contact with a first stock
rail 12A, the second inner rail 14B being spaced from the second stock rail 12B, as
shown in Figure 1, and a normal position (not shown), in which the first inner rail
14A is spaced from the first stock rail 12A, the second inner rail 14B being in contact
with the second stock rail 12B.
[0018] The railroad switch 10 is operated by a switching machine 20 according to the invention
and which comprises a throw bar 22, a lock bar 24, and a point detector bar 26. To
that end, the throw bar 22 is connected via a throw rod 28 to a rod connector 30 fixed
to the second rod 18, the lock bar 24 is connected via a lock rod 32 to a connector
lug 34 fixed to the front rod 26, and the point detector bar 26 is connected via a
connector rod 36 to a point detector attachment rod 38 which is fixed to one of the
inner rails 14A, 14B.
[0019] The switching machine 20 comprises a fixed frame 40 elongated along a longitudinal
direction X, and each one of the throw bar 22, lock bar 24, and point detector bar
26 is elongated along a transversal direction Y which is substantially perpendicular
to the longitudinal direction X. The longitudinal and transversal directions X, Y
define together a horizontal plane to which a vertical direction Z is perpendicular.
[0020] Each one of the throw bar 22, lock bar 24, and point detector bar 26 is translatable
relatively to the frame 40 along said transversal direction Y. In particular, the
lock bar 24 is translatable between a normal locking position (not shown) when the
inner rails 14A, 14B are in their normal position and a reverse locking position (not
shown) when the inner rails 14 are in their reverse position, and the point detector
bar 26 is translatable between a normal detection position (not shown) when the inner
rails 14A, 14B are in their normal position and a reverse detection position (not
shown) when the inner rails 14A, 14B are in their reverse position.
[0021] Preferably, the switching machine 20 also comprises a motor (not shown) to drive
the throw bar 22.
[0022] With reference to Figures 2 and 3, the lock bar 24 has a transversal groove 42 formed
in a front face of the lock bar 24, said groove 42 having a vertical flat bottom joining
an upper face of the lock bar 24. The lateral extension of the groove 42 is limited,
in other words, the groove 42 does not extend along the whole length of the lock bar
24.
[0023] The lock bar 24 has also locking slots 44 formed in a bottom face of the lock bar
24, each locking slot 44 emerging in a back face of the lock bar 24. The lateral extension
of these locking slots 44 is also limited. They are positioned so that one of said
locking slots 44 is substantially aligned with the longitudinal median axis M of the
frame 40 when the lock bar 24 is in its normal locking position and when the lock
bar 24 is in its reverse locking position.
[0024] The point detector bar 26 has a cylindrical surface 46 in which a notch 48 is formed.
It should be noted that "cylindrical" shall here be understood in its broadest sense,
including cases in which the cylindrical surface is not generated by revolution. In
particular, this notch 48 is formed by a section of the point detector bar 26 which
has a narrower diameter than the rest of the point detector bar 26. The lateral extension
of the notch 48 is limited. The notch 48 is positioned so that it is substantially
aligned with the longitudinal median axis M of the frame 40 when the point detector
bar 26 is midway between its normal and reverse detection positions.
[0025] With reference to Figure 3, the switching machine 20 further comprises a cam bar
50 lying at the bottom of switching machine 20. This cam bar 50 is elongated along
the longitudinal direction of the frame 40 and it has a longitudinal median axis which
is substantially collinear with that of the switching machine 20. The cam bar 50 has
a kinematic connection (not shown) with the throw bar 22 in such a manner that the
cam bar 50 and the throw bar 22 are jointly translatable relatively to the frame 40.
One end of the cam bar is an oblong cam surface (not shown) which coordinates the
movement of the throw bar 22 with the motor, so that the cam bar 50 moves linearly
along the longitudinal direction from a lock position to an unlock position and then
back to the lock position during the switching operation. In the unlock positon, the
cam bar 50 is at its furthest back position, as shown in the Figures and, in the lock
position, the cam bar 50 is at its furthest forward position in the switching machine
20.
[0026] The cam bar 50 comprises a cam body 52, a lock lug 54 in the form of a block attached
to the top surface of the cam body 52 at the far end opposite the cam surface. This
lock lug 54 is just low enough to slide through one of the locking slots 44 when the
lock bar 24 is in its normal or reverse position and just tall enough to catch on
the lock bar 24 if said lock bar 24 is not in the ideal position.
[0027] The cam bar 50 further comprises a tongue portion 56 extending from a point of the
top surface of the cam body 52. The tongue portion 56 consists in a flat, narrow bar
positioned substantially parallel to the cam body 52 and substantially aligned with
the longitudinal median axis M but raised to a higher vertical positon than the cam
body 52 via a block 58 at the end of the tongue portion 56 oriented toward the cam
surface. The end 60 of the tongue portion 56 opposite the block 58 features 45 degree
angled edges such that the very end of the tongue portion 56 is slightly narrower
than the rest of it.
[0028] Coming back to Figure 2, the switching machine 20 also comprises a contact assembly
62, two detector bar followers 64A, 64B designed to act on the contact assembly depending
on the position of the point detector bar 26, and two inhibiting elements 66, each
one being able to inhibit action on the contact assembly 62 of a respective one of
the detector bar followers 64A, 64B depending on the position of the cam bar 50.
[0029] The contact assembly 62 comprises two push-to-open switch devices 70. Each one of
these switch devices 70 is adapted so that, when a pressure is applied on this switch
device 70, the switch device 70 opens a respective electrical circuit (not shown)
connected to said switch device 70, so that the switch device 70 is said to be in
an "off" position. When the pressure is released, the switch device 70 closes said
respective electrical circuit, so that the switch device 70 is said to be in an "on"
position. At least one of the switch devices 70 needs to be in an "on" position so
that the switching machine 20 can detect that the railroad switch is in a safe configuration.
[0030] Each detector bar follower 64A, 64B is positioned on a respective lateral side of
the longitudinal median axis M. It is positioned vertically above and clear of the
lock bar 24 while being substantially at the same height as the point detector bar
26.
[0031] Each detector bar follower 64A, 64B is rotatable relatively to the frame 40 around
a substantially vertical rotation axis 72 between a proximal position, in which the
detector bar follower 64A, 64B acts on a respective one of the switch devices 70,
and a distal position, in which the detector bar follower 64A, 64B is away from said
switch device 70. The rotation axis 72 of the detector bar followers are substantially
transversally aligned and are transversally spaced away from each other.
[0032] Each detector bar follower 64A, 64B has a body 71 with an elongated, diamond shape
overall with two acute-angle corners and two obtuse-angle corners.
[0033] The detector bar follower 64A, 64B crosses the vertical rotation axis 72 at a pivot
point 74 situated at one of the obtuse-angle corners. At the opposite obtuse-angle
corner is located a correspondence pin 75 (Figure 3), protruding vertically from a
lower surface of the body 71, said pin 75 being fixed to the body 71 and being adapted
to engage the groove 42 of the lock bar 24 when the lock bar 24 is in one of its normal
and reverse locking positions and the detector bar follower 64A, 64B is in its distal
position.
[0034] Thus, in case the lock bar 24 and the point detector bar 26 are out of correspondence
with respect to each other at the end of a rail switching operation, one of the detector
bar followers 64A, 64B will have its correspondence pin 75 resting on the lock bar
24 outside of the groove 42 and will thus be prevented from reaching its distal position.
As a consequence, both detector bar followers 64A, 64B will keep acting on their respective
switch devices 70, so that the switching machine 20 will not be able to indicate a
"safe condition" of the railroad switch until the situation is corrected.
[0035] At one of the acute-angle corners a roller 76 is positioned, adjacent to the point
detector bar 26, and forms a follower part intended to be in contact with the point
detector bar 26. At the opposite acute-angle corner is an attachment point 78 which
is rotatably attached to an end of a respective one of the inhibiting elements 66.
[0036] Each detector bar follower 64A, 64B further includes a switch arm 80 protruding from
a top surface of the body 71 and extending substantially horizontally away from the
follower part 76. The switch arm 80 has a free end 82 opposite the body 71 with a
roller defining the contact surface of the detector bar follower 64A, 64B with the
respective switch device 70 when the detector bar follower 64A, 64B it in its proximal
position.
[0037] The respective positions of the follower part 76 and of the switch arm 80 are adapted
so that, when the follower part 76 is in contact with the cylindrical surface 46 of
the point detector bar 26, the detector bar follower 64A, 64B is in its proximal position
and, when the follower part 76 is received in the notch 48 of the point detector bar
26, the detector bar follower 64A, 64B is in its distal position.
[0038] Furthermore, the respective positions of the detector bar followers 64A, 64B and
of the point detector bar 26 are adapted so that reception in the notch 48 of the
follower part 76 of a first one of the detector bar followers 64A is possible only
when the point detector bar 26 is in its normal detection position, so that reception
in the notch 48 of the follower part 76 of a second one of the detector bar followers
64B is possible only when the point detector bar 26 is in its reverse detection position,
and so that none of the follower parts 76 of both detector bar followers 64A, 64B
can be received in the notch 48 without unmounting the switching machine 20 when the
point detector bar 26 is in its intermediary position.
[0039] Each inhibiting element 66 is positioned on a respective lateral side of the longitudinal
median axis M. It comprises a main body 84 which is pivotally mounted on the frame
40 around a substantially vertical pivoting axis 86 between a primary position shown
in Figure 2 and a secondary position (not shown). This pivoting axis 86 is nearer
from the longitudinal median axis M than the rotation axis 72 of the respective detector
bar follower 64A, 64B.
[0040] With reference to Figure 3, the main body 84 comprises a vertical pivot shaft 88
and two horizontal arms 90, 92. The pivot shaft 88 is vertically aligned with the
pivoting axis 86 and cooperates with a corresponding vertical pole (not shown) fixed
to the frame 40 to allow rotation of the main body 84 relatively to the frame 40.
The arms 90, 92 are vertically aligned and are vertically spaced away from each other,
a top arm 90 extending substantially horizontally from a top end of the pivot shaft
88 and a lower arm 92 extending substantially horizontally from a lower end of the
pivot shaft 88. In particular, the top arm 90 is positioned above the tongue portion
56 of the cam bar 50, and the lower arm 92 is positioned under said tongue portion
56. Each arm 90, 92 has a free end 94, opposite the pivot shaft 88, provided with
a hook.
[0041] Each inhibiting element 66 further comprises a stop 96 mounted on the main body 84
so that it follows the same horizontal displacement as the main body 84. This stop
96 is positioned so that it is able to abut against the tongue portion 56 of the cam
bar 50 when the main body 84 is in its primary position and the cam bar 50 is in its
unlock position, and so that it is away from the tongue portion 56 of the cam bar
50 when the main body 84 is in its primary position and the cam bar 50 is in its lock
position.
[0042] Each inhibiting elements 66 is articulated so that its stop 96 remains on a same
lateral side of the longitudinal median axis M between the primary and secondary positions
of the main body 84, the stop 96 being closer to the median longitudinal axis M when
the main body 84 in its secondary position than when the main body 84 is in its primary
position. Thus, the median longitudinal axis M extends between the stops 96 of the
inhibiting elements 66 whatever the position of these inhibiting elements 66, and
these stops 96 are closer to each other when the main bodies 84 of the inhibiting
elements 66 are in their secondary positions than when these main bodies 84 are in
their primary position. This has the consequence that, when the cam bar 50 is in its
unlock position, its tongue portion 56 prevents the inhibiting elements 66 and thus
the main bodies 84 from reaching their secondary positions. However, when the cam
bar 50 is in its lock position, its tongue portion 56 being away from the stops 96,
displacement of the inhibiting elements 66 between their primary and secondary positions
is allowed.
[0043] As a consequence, in case the lock bar 24 and the point detector bar 26 are out of
correspondence with respect to each other at the end of a rail switching operation,
the lock bar 24 preventing the cam bar 50 from reaching its lock position because
the lock lug 54 is not able to engage one of the locking slots 44, both stops 96 will
abut against the tongue portion 56 of the cam bar 50, thus preventing both detector
bar followers 64A, 64B from reaching their distal positions. Both detector bar followers
64A, 64B will therefore keep acting on their respective switch devices 70, so that
the switch machine 20 will not be able to indicate a "safe condition" of the railroad
until the situation is corrected.
[0044] Each inhibiting element 66 is jointly movable with its respective detector bar follower
64A, 64B so that its main body 84 is in its primary position when the detector bar
follower is in its proximal position and in its secondary position when the detector
bar follower 64A, 64B is in its distal position. To that end, each inhibiting element
66 comprises a connecting rod 98 connecting the main body 84 to the respective detector
bar follower 64A, 64B.
[0045] This connecting rod 98 is attached at one end to the respective detector bar follower
64A, 64B via the attachment point 78 described above, and at the other end to the
top and lower arms 90, 92 of the main body 84 via rotatable connections 99 which are
further away from the pivot shaft 88 than the stops 96.
[0046] The connecting rod 98 extends substantially parallel to the point detector bar 26,
from the attachment point 78 toward the longitudinal median axis M.
[0047] Advantageously, the connecting rod 98 is adjustable in length.
[0048] The switching machine 20 further comprises a biasing device 100 biasing the detector
bar followers 64A, 64B toward their distal positions. This biasing device 100 comprises
two extension springs 102, each one having a first end attached to the main body 84
of a first one of the inhibiting elements 66 and a second end attached to the main
body 84 of a second one of the inhibiting elements 66. In particular, a first one
of the springs 102 has its ends attached to the hooks provided at the free ends 94
of the top arms 90 of both main bodies 84, and a second one of the springs 102 has
its ends attached to the hooks provided at the free ends 94 of the lower arms 92 of
both main bodies 84.
[0049] The two springs 102 are therefore stretched horizontally between the arms 90, 92
of the two main bodies 84, roughly parallel to the point detector bar 26. These springs
102 thus work to draw the free ends 94 of the arms 90, 92 toward each other, biasing
these main bodies 84 toward their secondary positions. This has the consequence that
the connector rods 98 of both inhibiting elements 66 are pulled toward each other,
these connector rods 98 thus applying a biasing force on the detector bar followers
64A, 64B, at the attachment points 78, this force biasing the detector bar followers
64A, 64B toward their distal position.
[0050] Turning now to Figures 4 to 7, there is shown that the stop 96 of each inhibiting
element 66 (even though only one of these inhibiting elements 66 is shown of these
figures, the other one is the symmetrical counterpart of the shown inhibiting element
66) comprises a mobile shaft 104 and a roller 107 attached at a lower end of said
mobile shaft 104. The mobile shaft 104 has a shaft body 105 extending substantially
vertically through a hole 106 in the top arm 90 of the main body 84 and, at the top
of said shaft body 105, a flat, round head 108. The stop 96 is therefore vertically
translatable relatively to the main body 84 between an active position, shown in Figures
4 and 7, in which the stop 96 rests on the lower arm 92 of the main body 84, and a
passive position, shown in Figures 3 and 6, in which the stop 96 is at distance from
the lower arm 92, said distance being greater than the thickness of the tongue portion
56 of the cam bar 50. When the stop 96 is in its active position, the roller 107 is
able to be in contact with the tongue portion 56 of the cam bar 50 when the cam bar
50 is in the unlock position, thus hindering displacement of the main body 84 toward
its secondary position, and, when the stop 96 is in its passive position, the roller
107 is not able to be in contact with the tongue portion 56 of the cam bar 50 even
when the cam bar 50 is in the unlock position, thus allowing displacement of the main
body 84 toward its secondary position even when the cam bar 50 is in the unlock position.
[0051] A compression spring 109 is also mounted coaxially on said mobile shaft 104 between
the hole 106 and the roller 107 with a washer (not shown) between the spring 109 and
the roller 107 so that it acts as a biasing member biasing said stop 96 toward its
active position.
[0052] The switching machine 20 further comprises an actuation device to move the stops
96 of the inhibiting elements 66 between their active and passive positions. This
actuation device comprises a plate assembly 110 which is vertically translatable relatively
to the frame 40 in a displacement region constituted by the space extending vertically
above and under the plate assembly 110.
[0053] This plate assembly 110 comprises a bottom plate 112 and a top plate 114 connecting
the mobile shafts 104 of both inhibiting elements 66.
[0054] With reference to Figure 8, the bottom plate 112 comprises a slot 116 through which
the shaft bodies 105 of the mobile shafts 104 extend. Said slot 116 is a symmetrical
shape specially designed to allow the mobile shafts 104 to move normally during normal
operation. As such, said slot 116 has a swept shape that follows the path of the mobile
shafts 104 when the main bodies of the inhibiting members 66 are pivoted between their
primary and secondary positions.
[0055] Extending along the bottom planar edge of the slot 116 is a ridge 118 on which the
round heads 108 of the mobile shafts 104 are adjacent. The height of the slot 116
above the ridge 118 is sized such that the heads 108 of the mobile shafts 104 have
enough room to move between the bottom and top plates 112, 114 without excessive friction
preventing motion.
[0056] The top plate 114 comprises an oval slot 120 with no ridge such that it sandwiches
the shaft heads 108 when connected to said bottom plate 112 without pressing on said
shaft heads 108. Said slot 120 is just narrower than the heads 108 of the mobile shafts
104 such that it forms a lip to hold the mobile shafts 104. The bottom and top plates
112, 114 each feature a pair of two holes 122, with the top plate 112 featuring a
cutout 124 around said holes 122.
[0057] These bottom and top plates 112, 114 are held together via a vertical handle 126,
which also acts to enable maintenance personnel to lift the aforementioned plates
112, 114. Pulling said handle 126 up pulls the mobile shafts 104, thereby lifting
the stops 96 and compressing the springs 109.
[0058] The handle 126 is in the form of a round bar, bent at 90 degree angles 128 in two
places, with a length 130 at each end that is of a smaller diameter than the main
bar 132 such that a lip 134 is formed where the smaller diameter end 130 meets the
larger diameter main bar 132. The smaller ends 130 are inserted through the holes
122 in the bottom and top plates 112, 114, with the lip 134 abutting against the top
surface of the cutout 124 on the top plate 112. Bolts 136 are threaded onto the ends
130 of said handle 126 to hold the top and bottom plate 112, 114 together against
the lip 134 and to hold said handle 126 to said plates 112, 114.
[0059] The top plate 114 also comprises two arms 140 extending horizontally toward the front,
each with a metal mobile contact 142 mounted to the underside via a rivet 144. Each
mobile contact 142 is in the shape of an inverted V with a flat bottom 146. These
mobile contacts 142 are part of a safety circuit which must be closed for remote electrical
operation of the switching machine 20 to take place, said safety circuit further comprising
stationary contacts 148 (Figure 5) mounted to the top of a back plate 149 (Figure
6) which is fixed relatively to the frame 40. These mobile contacts 142 are positioned
so that, in the active position of the stops 96, they each bridge two of the stationary
contacts 148 to close the safety circuit and, in the passive position of the stops
96, they both are away from the stationary contacts 148, thus letting the safety circuit
open. Maintainers' safety from sudden switch machine operation which could be triggered
by a remote dispatcher is therefore ensured when the stops 96 are in their passive
position.
[0060] Returning to Figure 4 to 7, the switching machine 20 further comprises a latch assembly
150 for locking the plate assembly 110 in place.
[0061] With reference to Figure 9, this latch assembly 150 comprises a latch 152 having
a flat vertical shape and mounted on a horizontal shaft 154 with a torsion spring
156 onto a bracket 158, said bracket 158 being fixed relatively to the frame 40. In
particular, the bracket 158 features a pair of holes 160 for mounting to the pivot
shafts 88 of the main bodies 84 of the inhibiting elements 66.
[0062] The latch 152 comprises a front face 161 and a protrusion 162 protruding from said
front face 161, the protrusion 162 having a top face 164 and a bottom face 166. These
two faces 164, 166 are not quite parallel. If the top surface 164 is said to be horizontal,
the bottom surface 166 angles up slightly so as to be in the correct position for
holding said plate assembly 110 either up or down.
[0063] This latch 152 is rotatable relatively to the frame 40 around the horizontal shaft
154 between a latching position, in which the protrusion 162 extends within the displacement
region of the plate assembly 110, and a liberation position, in which the protrusion
162 is excluded from said displacement region.
[0064] The position of the plate assembly 110 when the stops 96 are in their passive position
is above the position of the protrusion 162 when the latch 152 is in its latching
position, and the position of the plate assembly 110 when the stops 96 are in their
active position is under the position of the protrusion 162 when the latch 152 is
in its latching position. The top face 164 of the protrusion 152 constitutes a resting
surface on which the bottom plate 112 rests when the stops 96 are in their passive
position, thus preventing the stops 96 from coming back to their active position,
and the bottom face 166 constitutes a pressing surface which rests on top of the top
plate 114 when the stops 96 are in their active position, thus preventing the stops
96 from being dislodged from their active position.
[0065] The front face 161 of the latch 152 comprises a flat front portion 168 just below
the protrusion 162. This flat portion 168 pushes against a back side of the plates
112, 114 when the stops 96 are in their active position, so that the spring 156 does
not lose tension. The front face 161 further comprises a curved front portion 170
below the flat portion 168; this curved front portion 170 is designed to prevent collision
with the top plate 114 when the stops 96 are in their active position.
[0066] The latch 152 further comprises an angled area 172 at its top, above the protrusion
162, and a spring rest area 174 at its back, behind the curved front portion 170.
The angled area 172 functions as a handle to pull said latch 152 out of the way to
lift the handle 126 when the stops 96 are in their active position. The spring rest
area 174 consists in a slot receiving a part of the torsion spring 156.
[0067] The torsion spring 156 acts as a biasing element biasing the latch 152 toward its
latching position. To that end, the torsion spring 156 features two tail ends 176,
which go into small holes located at the outer edge of the bracket 158, and a middle
loop 178 which applies pressure to the spring rest area 174 to hold the latch 152
into positon up against the aforementioned plate assembly 110. Thus, when the latch
152 is pulled to rotate back, the torsion spring 156 is tightened, increasing the
spring tension. The torsion spring 156 is also adapted to provide consistent rotational
pressure into the latch 152.
[0068] Thanks to the invention described above, preparing the switching machine 20 for the
Point Detector Integrity Test is facilitated. Indeed, to disconnect the functions
of the point detector bar 26 and of the lock bar 24, the maintainers merely need to
displace the stops 96 toward their passive position by pulling the handle 124 up while
pushing on the angled area 172 of the latch 152. When the handle 124 has been pulled
up, the latch 152 will return in its latching position, thus insuring that the stops
96 remain in their passive position.
[0069] There is in particular no need to disconnect the lock bar 24 or the point detector
bar 26 from the rails 14A, 14B, and therefore no need to readjust the position of
these bars 24, 26 relative to the rails 14A, 14B after the switching machine 20 has
been tested. Indeed, since, when the stops 96 are in their passive position, displacement
of the main bodies 84 between their primary and secondary positions is no longer conditioned
on the cam bar 50 being in its lock position, i.e. the positioning of the lock bar
24 relative to the came bar 50 and notably of the lock lug 54 relative to locking
slots 44 does not limit the movement of the main bodies 84 between their primary and
secondary positions, actuation of the contact assembly 62 by the detector bar followers
64A, 64B is consequently not conditioned on the lock bar 24 having reached its normal
or reversed position: the point detector bar 26 is thus isolated from the lock bar
24, so that a test can be run without both the point detector bar 26 and the lock
bar 24 respecting a precise positioning relatively to the frame 40 or relatively to
each other. As a consequence thereof, the number of tools is decreased, as well as
the time spent by the maintainers to realize the Point Detector Integrity Test. Furthermore,
there is no risk that the components of the switching machine 20 are not returned
to their proper adjustment after the test.
[0070] In addition, the switching machine 20 provides enhanced security to the maintainers,
since remote operation of the switching machine 20 is impossible when the stops 96
are in their passive position, which condition is necessary for the Point Detector
Integrity Test to be conducted. There is therefore no risk that the maintainers are
injured by a displacement of components of the switching machine 20 caused by a remote
operation of the switching machine 20 during the test.
1. A switching machine (20) for switching the position of railway tracks, the switching
machine (20) comprising:
- a frame (40), intended to be fixed relatively to a pair of stock rails (12A, 12B)
of a railroad switch (10),
- a throw bar (22) translatable relatively to the frame (40) along a transverse direction
(Y) to throw a pair of inner rails (14A, 14B) of the railroad switch (10), located
between the stock rails (12A, 12B), from a normal track position to a reverse track
position, and from the reverse track position to the normal track position,
- a point detector bar (26), translatable relatively to the frame (40) along the transverse
direction (Y) between a normal detection position intended to correspond to the normal
track position of the inner rails (14A, 14B) and a reverse detection position intended
to correspond to the reverse track position of the inner rails (14A, 14B),
- an indication contact assembly (62), fixed relatively to the frame (40), comprising
at least one switch (70),
- at least one detector bar follower (64A, 64B), movable relatively to the frame (40)
between a proximal position, in which the detector bar follower (64A, 64B) acts on
the switch (70), and a distal position, in which the detector bar follower (64A, 64B)
is away from the switch (70), the detector bar follower (64A, 64B) being adapted to
follow displacement of the point detector bar (26) in such a manner that, when the
point detector bar (26) is in one of its normal and reverse detection positions, the
detector bar follower (64A, 64B) is in a first position among the proximal and distal
positions and, when the point detector bar (26) is in an intermediary position between
its normal and reverse detection positions, the detector bar follower (64A, 64B) is
in the second position among the proximal and distal positions,
- an inhibiting element (66) jointly movable with the detector bar follower (64A,
64B) between a primary position when the detector bar follower (64A, 64B) is in its
first position and a secondary position when the detector bar follower (64A, 64B)
is in its second position,
- a cam bar (50) having a kinematic connection with the throw bar (22) in such a manner
that the cam bar (50) and the throw bar (22) are jointly translatable relatively to
the frame (40), the cam bar (50) comprising a tongue portion (56) and being translatable
relatively to the frame (50) along a longitudinal direction (X) between an unlock
position in which the tongue portion (56) is able to be in contact with a stop (96)
of the inhibiting element (66), preventing the inhibiting element (66) from reaching
its secondary position, and a lock position in which the tongue portion (56) is away
from the stop (96), allowing displacement of the inhibiting element (66) between its
primary and secondary positions,
characterized in that the inhibiting element (66) comprises a main body (84) relatively to which the stop
(96) is vertically translatable between an active position, in which the stop (96)
is in contact with the tongue portion (56) of the cam bar (50) when the cam bar (50)
is in the unlock position, preventing the inhibiting element (66) from reaching its
secondary position, and a passive position, in which the stop (96) is away from the
tongue portion (56) of the cam bar (50) when the cam bar (50) is in the unlock position,
allowing displacement of the inhibiting element (66) between its primary and secondary
positions.
2. The switching machine (20) of claim 1, wherein the inhibiting element (66) comprises
a biasing member biasing the stop (96) toward its active position.
3. The switching machine (20) of claim 1 or 2, comprising a latch assembly (150) to latch
the stop (96) in its passive position.
4. The switching machine (20) of any one of the preceding claims, wherein the stop (96)
comprises a vertical shaft (104) with a shaft body (105) extending through a hole
(106) formed in the main body (84) and, on top of the shaft body (105), a shaft head
(108) with a larger diameter than the diameter of the shaft body (105), and the switching
machine (20) comprises an actuation device to displace the stop (96) between its active
and passive positions, said actuation device comprising a plate assembly (110) which
is vertically translatable relatively to the frame (40), said plate assembly (110)
including a plate (112) having a slot (116) formed therein and through which the shaft
body (105) extends, said slot (116) having a shape that follows the path of the shaft
(104) when the inhibiting element (66) is displaced between its primary and secondary
positions.
5. The switching machine (20) of claims 3 and 4 considered together, wherein the latch
assembly (150) comprises a latch (152) with a front face (161) and a protrusion (162)
protruding from said front face (161), said latch (152) being rotatable relatively
to the frame (40) around a horizontal axis between a latching position, in which the
protrusion (162) extends within a displacement region of the plate assembly (110),
and a liberation position, in which the protrusion (162) is out of the displacement
region of the plate assembly (110), the position of the plate assembly (110) when
the stop (96) is in its passive position being above the position of the protrusion
(162) when the latch (152) is in its latching position, and the latch assembly (150)
further comprises a biasing element (156) biasing the latch (152) toward its latching
position.
6. The switching machine (20) of claim 4 or 5, comprising a safety circuit to detect
when the stop (96) is in its passive position, said safety circuit comprising at least
two stationary contacts (148) and at least one mobile contact (142) mounted on the
plate assembly (110) in a manner that, when the stop (96) is in one of its passive
and active positions, the mobile contact (142) bridges the two stationary contacts
(148), thus closing the safety circuit and, when the stop (96) is in the other one
of its passive and active positions, the mobile contact (142) is away from the stationary
contacts (148), thus opening the safety circuit.
7. The switching machine (20) of any one of the preceding claims, comprising two detector
bar followers (64A, 64B), each one being adapted to act on a respective switch (70)
of the indication contact assembly (62) when it is in its proximal position, the detector
bar followers (64A, 64B) comprising a first detector bar follower (64A) which is adapted
to be in its second position when the point detector bar (26) is in its normal detection
position and a second detector bar follower (64B) which is adapted to be in its second
position when the point detector bar (26) is in its reverse detection position.
8. The switching machine (20) of claim 7, wherein the stop (96) of the inhibiting element
(66) of each detector bar follower (64A, 64B) is closer to the inhibiting element
(66) of the other detector bar follower (64A, 64B) when both inhibiting elements (66)
are in their secondary position than when both inhibiting elements (66) are in their
primary position, and the tongue portion (56) of the cam bar (50) has a median longitudinal
axis which extends between both inhibiting elements (66).
9. The switching machine (20) of any one of the preceding claims, wherein the point detector
bar (26) has a cylindrical surface (46) in which a notch (48) is formed, the detector
bar follower (64A, 64B) is rotatable relatively to the frame (40) around a vertical
rotation axis (72) between its first and second positions and has a follower part
(76) adapted for contacting the point detector bar (26) in such a manner that, when
the follower part (76) is in contact with the cylindrical surface (46) of the point
detector bar (26), the detector bar follower (64A, 64B) is in its first position and,
when the follower part (76) is received in the notch (48), the detector bar follower
(64A, 64B) is in its second position, the main body (84) of the inhibiting element
(66) is rotatable relatively to the frame (40) around a vertical pivoting axis (86),
and the inhibiting element (66) comprises a connecting rod (98) connecting the detector
bar follower (64A, 64B) to the main body (84).
10. The switching machine (20) of claims 8 and 9 considered together, wherein the detector
bar followers (64A, 64B) have a common biasing device (100) comprising at least one
spring (102) having a first end attached to the main body (84) of the inhibiting element
(66) of the first detector bar follower (64A) and a second end attached to the main
body (84) of the inhibiting element (66) of the second detector bar follower (64B),
said common biasing device (100) biasing both detector bar followers (64A, 64B) toward
their second position.
Amended claims in accordance with Rule 137(2) EPC.
1. A switching machine (20) for switching the position of railway tracks, the switching
machine (20) comprising:
- a frame (40), intended to be fixed relatively to a pair of stock rails (12A, 12B)
of a railroad switch (10),
- a throw bar (22) translatable relatively to the frame (40) along a transverse direction
(Y) to throw a pair of inner rails (14A, 14B) of the railroad switch (10), located
between the stock rails (12A, 12B), from a normal track position to a reverse track
position, and from the reverse track position to the normal track position,
- a point detector bar (26), translatable relatively to the frame (40) along the transverse
direction (Y) between a normal detection position intended to correspond to the normal
track position of the inner rails (14A, 14B) and a reverse detection position intended
to correspond to the reverse track position of the inner rails (14A, 14B),
- an indication contact assembly (62), fixed relatively to the frame (40), comprising
at least one switch (70),
- at least one detector bar follower (64A, 64B), movable relatively to the frame (40)
between a proximal position, in which the detector bar follower (64A, 64B) acts on
the switch (70), and a distal position, in which the detector bar follower (64A, 64B)
is away from the switch (70), the detector bar follower (64A, 64B) being adapted to
follow displacement of the point detector bar (26) in such a manner that, when the
point detector bar (26) is in one of its normal and reverse detection positions, the
detector bar follower (64A, 64B) is in a first position among the proximal and distal
positions and, when the point detector bar (26) is in an intermediary position between
its normal and reverse detection positions, the detector bar follower (64A, 64B) is
in the second position among the proximal and distal positions,
- an inhibiting element (66) having a main body (84) and being jointly movable with
the detector bar follower (64A, 64B) so that its main body (84) is in a primary position
when the detector bar follower (64A, 64B) is in its first position and in a secondary
position when the detector bar follower (64A, 64B) is in its second position,
- a cam bar (50) having a kinematic connection with the throw bar (22) in such a manner
that the cam bar (50) and the throw bar (22) are jointly translatable relatively to
the frame (40), the cam bar (50) comprising a tongue portion (56) and being translatable
relatively to the frame (50) along a longitudinal direction (X) between an unlock
position in which the tongue portion (56) is able to be in contact with a stop (96)
of the inhibiting element (66), preventing the main body (84) of the inhibiting element
(66) from reaching its secondary position, and a lock position in which the tongue
portion (56) is away from the stop (96), allowing displacement of the main body (84)
of the inhibiting element (66) between its primary and secondary positions,
characterized in that the stop (96) is vertically translatable relatively to the main body (84) between
an active position, in which the stop (96) is in contact with the tongue portion (56)
of the cam bar (50) when the cam bar (50) is in the unlock position, preventing the
main body (84) from reaching its secondary position, and a passive position, in which
the stop (96) is away from the tongue portion (56) of the cam bar (50) when the cam
bar (50) is in the unlock position, allowing displacement of the main body (84) between
its primary and secondary positions.
2. The switching machine (20) of claim 1, wherein the inhibiting element (66) comprises
a biasing member biasing the stop (96) toward its active position.
3. The switching machine (20) of claim 1 or 2, comprising a latch assembly (150) to latch
the stop (96) in its passive position.
4. The switching machine (20) of any one of the preceding claims, wherein the stop (96)
comprises a vertical shaft (104) with a shaft body (105) extending through a hole
(106) formed in the main body (84) and, on top of the shaft body (105), a shaft head
(108) with a larger diameter than the diameter of the shaft body (105), and the switching
machine (20) comprises an actuation device to displace the stop (96) between its active
and passive positions, said actuation device comprising a plate assembly (110) which
is vertically translatable relatively to the frame (40), said plate assembly (110)
including a plate (112) having a slot (116) formed therein and through which the shaft
body (105) extends, said slot (116) having a shape that follows the path of the shaft
(104) when the main body (84) of the inhibiting element (66) is displaced between
its primary and secondary positions.
5. The switching machine (20) of claims 3 and 4 considered together, wherein the latch
assembly (150) comprises a latch (152) with a front face (161) and a protrusion (162)
protruding from said front face (161), said latch (152) being rotatable relatively
to the frame (40) around a horizontal axis between a latching position, in which the
protrusion (162) extends within a displacement region of the plate assembly (110),
and a liberation position, in which the protrusion (162) is out of the displacement
region of the plate assembly (110), the position of the plate assembly (110) when
the stop (96) is in its passive position being above the position of the protrusion
(162) when the latch (152) is in its latching position, and the latch assembly (150)
further comprises a biasing element (156) biasing the latch (152) toward its latching
position.
6. The switching machine (20) of claim 4 or 5, comprising a safety circuit to detect
when the stop (96) is in its passive position, said safety circuit comprising at least
two stationary contacts (148) and at least one mobile contact (142) mounted on the
plate assembly (110) in a manner that, when the stop (96) is in one of its passive
and active positions, the mobile contact (142) bridges the two stationary contacts
(148), thus closing the safety circuit and, when the stop (96) is in the other one
of its passive and active positions, the mobile contact (142) is away from the stationary
contacts (148), thus opening the safety circuit.
7. The switching machine (20) of any one of the preceding claims, comprising two detector
bar followers (64A, 64B), each one being adapted to act on a respective switch (70)
of the indication contact assembly (62) when it is in its proximal position, the detector
bar followers (64A, 64B) comprising a first detector bar follower (64A) whose main
body (84) is adapted to be in its second position when the point detector bar (26)
is in its normal detection position and a second detector bar follower (64B) whose
main body (84) is adapted to be in its second position when the point detector bar
(26) is in its reverse detection position.
8. The switching machine (20) of claim 7, wherein the stop (96) of the inhibiting element
(66) of each detector bar follower (64A, 64B) is closer to the inhibiting element
(66) of the other detector bar follower (64A, 64B) when the main bodies (84) of both
inhibiting elements (66) are in their secondary position than when the main bodies
(84) of both inhibiting elements (66) are in their primary position, and the tongue
portion (56) of the cam bar (50) has a median longitudinal axis which extends between
both inhibiting elements (66).
9. The switching machine (20) of any one of the preceding claims, wherein the point detector
bar (26) has a cylindrical surface (46) in which a notch (48) is formed, the detector
bar follower (64A, 64B) is rotatable relatively to the frame (40) around a vertical
rotation axis (72) between its first and second positions and has a follower part
(76) adapted for contacting the point detector bar (26) in such a manner that, when
the follower part (76) is in contact with the cylindrical surface (46) of the point
detector bar (26), the detector bar follower (64A, 64B) is in its first position and,
when the follower part (76) is received in the notch (48), the detector bar follower
(64A, 64B) is in its second position, the main body (84) of the inhibiting element
(66) is rotatable relatively to the frame (40) around a vertical pivoting axis (86),
and the inhibiting element (66) comprises a connecting rod (98) connecting the detector
bar follower (64A, 64B) to the main body (84).
10. The switching machine (20) of claims 8 and 9 considered together, wherein the detector
bar followers (64A, 64B) have a common biasing device (100) comprising at least one
spring (102) having a first end attached to the main body (84) of the inhibiting element
(66) of the first detector bar follower (64A) and a second end attached to the main
body (84) of the inhibiting element (66) of the second detector bar follower (64B),
said common biasing device (100) biasing both detector bar followers (64A, 64B) toward
their second position.