Note: Descriptions are shown in the official language in which they were submitted.
CA 02524204 2005-10-31
Device for the Remote Monitoring of Railway Switch Drives
The invention relates to a device for the remote monitoring of
railway switch drives operated via four lines, for instance by
three-phase current, or of a monitoring circuit operated via
four lines and including electric contacts which are switched as
a function of the position of the railway switch and via which,
upon reaching of the respective end position of the switch
tongue, a monitoring circuit is closed across said four lines,
for a railway' switch monitor fed, for instance, by direct
voltage, wherein a plurality of checking planes arranged in an
offset manner in the longitudinal direction of the rails are
provided and in each checking plane at least four electric
SwitC hiiig COiitaCtS are ClrCuited tGget her and CGOperate wltii
moved parts of the railway switch drive or railway switch, for
instance a check rod. in a manner that in an end position of the
switch tongue two electric switching contacts are each in the
closed, and two electric switching contacts are each in the
open, switching position and the switching position of each of
the electric switching contacts is changed once at a changeover
into the other end position of the switch tongue_
A device of the initially defined kind can, for instance, be
taken from EP 0 052 759 A2. In that known device, it is departed
from an electronic switch tower for feeding and remotely
monitoring a railway switch drive that is operated by three-
phase current via four lines. In the star point connections of
the motor windings are arranged contacts controlled by the
drive, via which the motor windings can be connected to the
three-phase mains upon closure of the switching-on contacts and
via which, upon rotation of the actuatG_r and reaching of the
reSpeCtlve n2vT end pOS~tlOn, a mOnitOrlng ClrClllt ~S CIOSed
aCrCSS the ~ Our I i neS a C1 three vli ndi n gS O f the urn v a ~ O r a
railway SwltCh COntr01 ClrCu i t ~ ed, dS .. rill e, wi th di reCt
CA 02524204 2005-10-31
2
voltage. The motor windings during rotation in correct operation
are fed symmetrically and fed asymmetrically at least during
run-down. The monitoring device responds to the monitoring
currents via respectively associated diodes and via connection
contacts of a running-direction selector, whereby the setting
current is switched off and the monitoring voltage is switched
on with the railway switch having assumed one of the two end
positions. Upon rotation of the drive and reaching of the
respective new end position, the monitoring circuit conducted
across two' of the four end position contacts, the three motor
windings and the four three-phase current lines will close in a
manner that a thus formed power circuit will signal the correct
functioning of the electric end position switches. Further
devices of the initially defined kind are, for instance, known
from DE 36 38 681 Al, in which the remote monitoring of three-
phase railway switch drives is performed by the aid of two
current-direction sensitive indicators connected in parallel via
connection contacts of a running-direction selector_ A
monitoring direct voltage source will feed a control potential
to the two indicators via the three-phase line, the motor
windings of the drive and the end position contacts, if the
drive assumes one of its end positions_
F_rom.DE 198 19 162 A1, another device of this type for a railway
switch comprising several switch drives can be taken. The er_d
positions of the switch drives are monitored in that the
respective end position messages of the individual further
switch drives are combined to a summation message. The circuitry
in this case is to safeguard that the monitoring circuit will be
realized only if a11_ or the respective, commonly monitored
drives assume i denti cal- end pos i ti ons . In the ever_t o f cut-of f
SwltC~? dr i veS, the nOrma 1 OSi ti OnS O f a1_1_ ~ ' --~ '
p e_ she con__ect ~ ng
rclayS arc _i_On i tOrcd.
' CA 02524204 2005-10-31
3
In the initially mentioned device k_n_own from EP 0 052 759 A2, a
number of additional monitorings were effected and centrally
detected. Common to all known devices is that in the event the
configuration is to be used for a plurality of checking planes
without any basic changes in the lines involved, the signals
combined to a summation message will in certain special cases
not be suitable to monitor all of the electric switches, and
maladjustments of an electric switch may, therefore, lead to
that a monitoring circuit will still build up and the respective
error message will not occur, or cannot be evaluated.
Departing from the initially described device for feeding and
remotely monitoring railway switch drives operated by three-
prlase Gi.irreiit via fGur lliieS, t he preSeiit liiveiitlOn alms t0
ensure the safe monitoring of several checking planes of one and
the same railway switch without any increase in lines involved
and without any adaptation work worth mentioning, and to enable
the safe check of all electric switches of a plurality of
checking planes of the same or several railway switches by a
single monitoring unit_ To solve this object, the device
according to the invention consists essentially in that the
electric switching contacts of several checking planes are
connected with one another in a manner that in the respective
end positions of the switch tongue all of the closed electric
switching contacts of the checking planes connected with one
another a_re connected in series to form a respective monitoring
circuit. While in the known configurations oizly part of the
electric switches were each always connected in series and other
electric switches were connected in parallel, in the
configuration of the invention, by which the electric switching
contacts of several checking planes are connected with one
another i_n_ a manner that al 1 of the c1 osed e1 ectri c swi tchi ng
CCntGCLS, l _e. al l_ p. t_h_e CGn~cCtiGI?S- -- that are CO='?duCtlve t0
fOrTti the c~lOCking Ci_rCUi_t, a_re CO_n_ncCted . n cCri eS~ a--- --
suiTLitati On
CA 02524204 2005-10-31
4
signal will actually be formed, and the monitoring circuit will
actually close, only if all of the switches of several checking
planes are actually working and the changeover of the railway
switch was correct.
Yet, in order to ensure correct working and the necessary check,
not only the electric switch position as such, but also the
respective time required by the three-phase motor for the
switching procedure are essential criteria to be evaluated for
the correct working of the railway switch and its safety. The
configuration in this respect, as known per se, is devised such
that motor windings of a three-phase motor are' connected in
series with the electric switching contacts and connectable to
the three-phase mains via the same, wherein the configuration ire
a particularly advantageous manner is devised such that the
mOnitOring CirCpit COrreSpOnding fi0 One pf the end pOSi_ti_OnS and
the monitoring circuit corresponding to the other of the end
positions are connected with each other in a manner that the
monitoring circuits will be connected to a star point connection
at the occurrence of a malfunction of at least one of the
electric switching contacts or a faulty setting of the railway
switch in at least one checking plane. If a failure of an
e1 -ect ri C gyii tChi ng COntaCt OCCLIrS, a ne~~T Star pOi nt CO_n_neCt i On
can be formed with this switching arrangement, whereby the
correct function, or a malfunction, can be directly concluded
from the parameters: period of changeover and current
consumption of the three-phase d_rive_
An absolute potential separation between logics and power range
is to be ensured both in the signaling and in the setting modes
o- operation. As already mentl0ned in the beginning, the voltage
in the monitorir_g circuit, as a _rule, is a d?_rect voltage,
4.~~leT eaS the pOW~e- =ange, aS a rll ~ e, i S T~Q jay a three-phase
source. D~,~_r i ng a setti ng prOCedtire, it i s to be taken care that
' CA 02524204 2005-10-31
.. 5
the drive will be switched off upon reaching of the end
position, in order to ensure the respective potential separation
required for the subsequent check. If the end position is not
reached, the drive will have to be switched off after a
maximally admissible running time, thus enabling an error to be
immediately recognized or evaluated by verification of the
summation signals_
The switching arrangement according to the invention, which
connects a plurality of checking planes with one another, can be
realized with conventional electric switches or electric
switching contacts or controlled electric contacts such that the
only expenditure involved is limited to connecting the electric
COntaCtS 1n th a COrreCt manner 1n Order t0 .enable tile deSlred
series connection in any position. In this context, the
configuration advantageously is devised such that two electric
switching contacts each of a checking plane, which have
different switching positions, are combined in a switch
component and cooperate with a common actuating member_ In
principle, electric switching contacts of a checking plane need
not necessarily be redundant. However, in order to ensure the
redundancy necessary for the series connection according to the
invention also in those cases; the total number of electric
switching contacts must comply with the criteria of redundancy.
To this end, the configuration is devised such that the number
of electric switching contacts of all checking planes
corresponds to an integral muitipie of eight. With such a number
of electric switching contacts and the respective crosswise
connection or self-monitoring mode of construction in a first
checking plane, it is feasible to safely avoid shunts or
parallel connections in all switching positions such that the
required Seri eS COnn2Cti On by w~'?1Ct'1 a S~.~~1'Tlat' On Slgnal Ca'_.1 be
CO rreCtl y de termi ned ~ O- all O f tile a l eCtrlC S'svi tChlng COntaCtS
to be mOnltOred G'%111 aCtuall~r always be guaranteed.
' CA 02524204 2005-10-31
6
In the preferred embodiment, the device according to the
invention is further developed in a manner that at least two
electric switching contacts are connected in series having the
same switching position at the same end position of the switch
tongue, wherein, in a further preferred manner, two electric
switching contacts having different switching positions, of an
electric switch component are linked with each other for the
same end position of the switch tongue. This safeguards enhanced
failure disclosure.
Finally, the configuration may also be devised such that three
electric switching contacts,-of which at least two comprise
difierer~t switchirLg positions, are combined in an electric
switch component to cooperate with a common actuating member_ In
this case; three instead of two electric switching contacts are,
thus, each integrated in a component and commonly actuated,
wherein two such electric switch components can be arranged in
the checking plane such that a total of six electric switching
contacts are provided.
In order to increase the operating safety, further marginal
condition are to be observed, wherein above all the wiring of
the first checking plane for the complete series connection
requires special attention irrespective of the respective
position. In this context, the configuration may either be
dev,_'sed such that a separate, self-monitoring checking unit is
arranged in a first one of sai d checking planes connected with
one another, or be devised such that the electric switch
components allocated to a first one of said checking planes
connected with one another are crosswisel_y c,'__rcuited. In both
cases, it ,s ensured in the first checking plane that no
i~t=?~eS i red Si'?ll~ tS wi ~ 1 OCCllr al-?d, as a YeSLtI t, ~.he Ser 1e S
ConneCtlo_n_ Will actually always be EnSUred fo_r al_l ClpSed
' CA 02524204 2005-10-31
.. 7
electric switching contacts of a plurality of checking planes
each.
In the following, the invention will be explained in more detail
by way of exemplary embodiments of different switching states
schematically illustrated in the drawing_ Therein, Figs. 1 to 8
depict a monitoring device according to the prior art, Fig. 9
illustrates the schematic structure of the monitoring device
according to the invention, and Figs. 10 to 16 are circuit
diagrams of the monitoring device according to the invention in
different states of the railway switch.
Fig_ 1 schematically illustrates a railway switch drive l, which
is fed via four feed lines 2, 3, 4 and 5 and capable of beir~g
controlled and monitored from a switch tower. The drive 1
COmpri geC a three-pha.Sg rnOtOr i__n_Cl_udi__n_g WlndlngS U; V arid w,
which are connected in a known manner with the electric
switching contacts 6, 7, 8 and 9. A rotary current mains
including three phases L1, L2, L3 as well as the common center
point conductor serves as power supply means for a changeover of
the drive. Further arranged in or between two of the three
external conductors L1, L2 and L3 is a railway switch running-
direction selector not illustrated ,'_n detail; via which; for
instance, the phase positions of the currents flowing on the
outer conductors L1 and L2 for the right-handed and the left-
handed rotation, respectively, of the drive are interchangeable_
In Fig. 1, the electric switching contacts 6, 7, 8 and 9 are
switched in a manner that the -phases L1, L2 and L3 are
interconnected to a star point 10 such that the three-phase
motor can be operated at full power.
Figs. 2a and 2b exempt i f y tiao confi g~u_rati o_n_s of et ectri C swi tch
COriL~Onej"? LS ~ ~ anQ 1 2 1n h'.'1l Ch ~ vYTO cl eCl.r1 i ; ~..og Yl ~ .
_ , __ c sw_~ch__. co__~ac~s
are eaCrl COTTLb-ned. The el2Ctr~ C SW ~ tCh COmDOn2nt t ~ COTiI~i"lScS
CA 02524204 2005-10-31
electric switching contacts 6 and 7, the electric switch
component 12 comprises electric switching contacts 8 and 9. The
electric switching contacts 6, 7 and 8, 9 each arranged in one
electric switch component 11 and 12, respectively, are allocated
a common actuating member 13, which, for instance, 'cooperates
with grooves 15 and 16 formed in a check rod 14. In Fig. 2, the
actuating member 13 of the electric switch component 12 engages
in the groove 15 and is therefore in the released state. The
electric switch component 11, on the other hand, is in the
tensioned position. The switch positions illustrated in Fig. 2
correspond with one of the two end positions of a railway switch
tongue, or a movable frog. In the other end position of the
switch tongue, the electric switch component 12 is in the
tensioned position and the electric switch component 1i ds in
the released position- During the resetting movement, both
l +- ' ~ h r.,~mr~vynt ~ 1 ~ 1 2 a re t' en C l ~l'1 Pd > The two
c l a f-. L r 1 c s vv 1 L. c t 1 a v m , ~ ,
electric .switching contacts 6, 7 and 8, 9 of the electric switch
components 11 and 12, respectively, are in different switching
positions-
From this results in the right-hand end position the circuit
diagram represented in Fig. 3. In this right-hand end position,
the feed limes 2, 3, 4, 5 by the s;~>itch tc~f:er are irterconrected
in a manner that a monitoring circuit can build up across the
four feed lines 2, 3, 4, 5 and the three motor windings U, V, W.
The monitoring circuit is designed as a direct voltage circuit
having a feed voltage of 60 Volts- If the correct right-hand end
position of the switch tongue is assumed, the monitoring circuit
will be closed and extend across feed line 2, motor winding V,
electric switching contact 8, feed line 3, monitori_n_g relay Wy,
f eed 1_i._-,2 4, fi~oto_r w,'_nd;r,a U, e1 ect_ric switching contact 7,
motor In%i ndi ng ~r and feed 1i ne 5 .
CA 02524204 2005-10-31
9
In Fig. 4 it is anticipated that the switch computer of the
switch tower has issued the switch command for switching the
railway switch, whereby the monitoring circuit is opened, and
the feed circuit for the drive motor is closed, by the switch
tower. The winding V of the drive motor lies at the phase
voltage, whereas the windings U and W lie at the phase-to-phase
voltage between phases L2 and L3. The drive motor starts
rotating, yet without the electric switching contacts 6, 7, 8, 9
being initially switched over. In this starting phase, the motor
starts running at a torque of about 700_ Then the electric
switching contacts 8, 9 are switched over in the starting phase,
since the actuating member 13 of the electric switch component
12 is pressed out of the groove 15 of the check rod_ Hence
results the circuitry illustrated in Fig. l, in which the motor
windings are star-connected_
Fig_ 5 depicts the feed circu,'_ts of the drive in the run-down
phase shortly before the drive motor is switched off. In this
phase, the electric switching contacts 6, 7 too have changed
their switching positions and thus separated the star point
connection of the motor windings. The motor is now
asymmetrically excited via the phase voltage and the phase-to-
phase voltage; w_h_ereby the motor coati noes to ru_n_ at 70 ~ of the
torque. Via the center point conductor Mp, the switch tower
recognizes that the changeover has been completed. At the switch
tower, the feed voltage for the three-phase motor is, therefore,
cut off and the monitoring voltage for the left-hand end
position ,'_s applied. T_h_ereby, a monitoring circuit as
illustrated in Fig. 6 builds up across feed line 4, motor
winding U, electric switching contact 6, feed line 3, monitoring
relay WL, feed 1 ine 2, motor w,'_nd; ng V, ei_ect_ric sSaltcl_-li_ng
ccntact 9, motor w,'_ndi ng v;~ a_n_d f eed 1 ,'-ne 5.
' CA 02524204 2005-10-31
IO
In the illustration according to Fig. 7 the situation in which
the railway switch was run through, i_e. trailed against the
position defined by the switch command executed last, is shown.
The two electric switching contacts 6 and 7 have changed their
switching positions. Due to the contact _change, the hitherto
existing monitoring circuit was interrupted with the monitoring
relay Wu being released and the driving relay WA being picked
up. The application of the feed voltage again causes the
formation of a star connection of phases Ll, L2, L3 such that
the three-phase current can again be applied for a new
changeover.
Fig. 8 illustrates a circuitry as provided according to the
prior art in a monitoring device that takes into account several
checking planes arranged in an offset manner in the longitudinal
direCtiO~ Of the railc_ FaCh Of the checking planes 17; 18 and
19 comprises a checking circuit including two electric switch
components each having two electric switching contacts
interconnected in a cascade-like manner. In the illustration
according to Fig. 8, the monitoring voltage for the right-hand
rail end position has been applied, and it is apparent that the
faulty behavior of individual contact switches is not
recognized. With the correct functioning of all electric
switching contacts, whereby the electr,'_c switching contact 20
would be open and the electric switching contact 21 would be
closed, the monitoring circuit should extend across the electric
switching contact 21 as indicated by broken lines. At a
malfunctioning of the electric switching contacts 20 and 21,
which are combined to an electric switch component according to
the electr,'_c switch component 11 and 12, respect,'_vely, (as
1_l_~astrated i n F i g. 8 ) , t_h_e e1 ectri c swi aching con tact 20 is,
hOWever, Cl OSed and the el_eCtri C Swi tCh ~ ng COntaCt 22 iS Open,
SO that t~''_c mOn ~ tOryg ClrClllt tn~i 1 1 ncverth°1 eSS be C1 OSed
vi ca
the electric sw,_'tching contact 20. Such malfunctioning _will not
CA 02524204 2005-10-31
11
be recognized by the switch tower, because the individual
electric switching contacts are connected in parallel, so that
no summation signal that would indicate the malfunctioning even
of a single electric switching contact will be available.
It is, therefore, proposed according to the invention that the
electric switching contacts of several checking planes are
connected with one another in a manner that all of the closed
electric switching contacts of the interconnected checking
planes will be connected in series in the respective end
positions of the switch tongue. A schematic illustration of a
monitoring device according to the invention is depicted in Fig.
9. The individual checking planes are denoted by l7, 18 and 19,
and electric switch components A, B, C and D are apparent, each
of which comprises two electric switching contacts having
i_ rr ' i 1.. ' ' .~ ' T.., +-1-,~ ~r,l l ~c.ni mrr Ty.'yrri~reC '~~'1P
C1111ere11t swl~i:lliW g pvSi~lvuS. 111 1.116 lVlWJVViy 7,,. .,,
electric switching contacts of the individual electric switch
components are denoted by Al/2, A3/4, Bl/2, B3/4, C1/2, C3/4 and
Dl/2, D3/4, respectively, wherein two electric switching
contacts may each be integrated in an electric switch component,
for instance electric switching contacts A1/2 and A3/4 in
electric switch component A. The electric switch components can
' 1 l +- +- ~ ' ~i 2~ nd 2b 'The ~lri~Te mnt r
be COni igurcu as ii.LUS ~..rcm.cv 1i. i gS . a a . o
is denoted by M and the switch tower is denoted by St. Fig. 10
depicts the circuitry of the individual electric switching
contacts, wherein, based on a first drive end position
monitoring 22, three additional checking planes 17, 18 and 19
are consecutively arranged and connected in series_ In the end
position shown in Fig_ 10, the monitoring circuit is closed and
optically emphasized. It is apparent that all of the electric
Switching contacts closed in this end position of the switch
tongue are connected in series faith the monitor~ng circuit each
e~tendir~g aCrOSS the electric switching coma ds A1/2, B1/2,
C3/4 and D3/C of the indi v, dual ch ticking p1 antis _ i n the other
CA 02524204 2005-10-31
12
end position of the switch tongue, a monitoring circuit
extending across the electric switching contacts C1/2, Dl/2,
A3/4 and B3/4 of the individual checking planes would result, as
indicated by broken lines. It is apparent that the monitoring
circuit connects all of the respectively closed electric
switching contacts in series such that the malfunctioning of a
single switching contact arranged in the row will cause the
interruption of the monitoring circuit in a manner that the
malfunctioning of a single electric switching contact will be
recognized any time. The monitoring circuits corresponding to
the two end positions of the switch tongue (indicated in Fig. 10
by full lines and by broken lines, respectively) are connected
via connections 23 in a manner that a star connection will
result from a malfunctioning of any of the electric switching
contacts such that the three-phase motor will continue to run
,__ . g L ~. g ,~ +r, -~a , +-y ue1-~a ~T~or ~.,; 1 1 ha rPCOCrn_i_zed
Ql.lrlll the t:llall eV ver aiiu t.me i ui v
by the switch tower on account of the exceeded changeover
period. Fig. 11 depicts the situation in which the electric
switch component comprising the electric switching contacts B1/2
and B3/4 in the checking plane 19 does not indicate the reaching
of the desired end position, so that the monitoring circuit will
be interrupted and a star-point connection with star point 10
W111 reSUlt Such that the three-phase ~:CtCr vT111 COntirsiiP t0 run
at full power. Thus, the point of connection for the star point
of the first checking plane with a conventional four-wire
technique is shifted under inclusion of the individual checking
planes and thereby enables the conductance of the monitoring
current path through the individual star points of the checking
planes_
In the lowermost connection plane 22, a self-monitoring
mOni tOrlng unit Or c C?"OSSvei_Se COnneCtiOn Of two e1 eCtri C SWltCh
components may be provided, as indicated in Fig. 10, for
instance, for switch compo_n_ents B and D. Such a crosswise
CA 02524204 2005-10-31
13
connection safeguards the constant monitorability of all of the
consecutively arranged electric switching contacts in the
respective end position upon application of the monitoring
circuit. Alternatively, a separate electric switch component E
may be employed as illustrated in Fig. 16. The electric switch
component E in this case may be designed in accordance with Fig.
2b_
An external feature such as, e.g., a trailing signaling means 32
may be integrated in this device for the remote monitoring of
railway switches.
The monitoring device according to the invention can also be
integrated into a separate four-wire monitoring circuit_ Ir~ Fig.
12, a contact ,circuitry is illustrated, which comprises a
mvnitvrinr'r rel a« 23 acti nn ; n both d; recti o_n_s. If a single one
r
of the numerous electric switching contacts fails, the
monitoring current fed at, for instance, 48 Volts will be unable
to flow and the railway switch arrangement will have to be
checked. As in contrast to the illustration according to Fig.
12, in which the monitoring circuit is closed and consequently
no error message is indicated, the electric switch component A
during the switehover accordi ng to Fi g. 13 wi l l not be reset
upon reachi ng of the desired end position of the rai 1 such that
the monitoring relay will be short-circuited, which will appear
as an error message in the switch tower_
Overall, it is advantageous if a number of electric switching
contacts corresponding to an integral multiple of eight are
circuited together in the monitoring device according to the
i nver._tion, and it i s, there f ore, requi _red wi th but two e1 ectri c
switch components arranged in one checking plane to combine a
grOi~p Of fOLr e1 eCtri C STnTi_tCh CO:!?pOnentS each i_?'? a ~!a_n__n_e-r
that a
g-Oup O ~ tHTO e1 eCtri C swi tCh COmpO=len tS W1~ 1 each be e?~ranged i n
CA 02524204 2005-10-31
I4
the released position and two electric switch components will
each be in the tensioned state, as is the case with the checking
plane 19 in Figs_ 9 to 11. A checking plane may be arranged in
the drive plane or within the extension of the tongue or of the
movable frog_
Fig. 14 depicts another structural design of an electric switch
component 25, 26, in which three electric switching contacts are
each combined_ Electric switch component 25 comprises electric
switching contacts 27, 28, 29. The electric switching contacts
27, 28, 29 and 24, 30, 31 respectively arranged in an electric
switch component 25 and 26 are allocated a common actuating
member 13 cooperating, for instance, with grooves 15 and 16
forWed lit a Check rod 14:
The electric switch component 26 engages in the groove 15 by its
actuating member 13 and is in the released position with the
electric switching contact 30 closed and the contacts 24 and 31
opened. The electric switch component 25 by contrast is in the
tensioned state with the electric switching contacts 27 and 28
closed and the electric switching contacts 29 opened. The switch
positions illustrated in Fig. 14 correspond to one of the two
end positions of the switch tongue or movable frog.
The checking device according to the invention can be assembled
by electric switch components as described in Fig. 14_ It is
apparent that all of the electric switching contacts closed in
the end position of the switch tongue are again connected in
series and a monitoring circuit closes as illustrated in Fig.
15, extending across the electric switching contacts All/12 and
C4/3 and C13/14, respectively, o~ the individual checking
p1 arses .
