Improvements connected with Railway Switches, Points, and Signals.
Year: 1894

page_text: Date of Application, 9th Feb., 1894
Complete Specification Left, 9th Nov., 1894-Accepted, 15th Dec.. 1894
PROVISIONAL SPECIFICATION.
Improvements connected with Railway Switches, Points, and
Signals.
1 EDWARD WALLER STONEY of the Chief Engineer's Office, Madras
Railway Company, Madras, in the Indian Empire, Engineer, do hereby declare the
nature of my invention to be as follows:-
My invention has for its object to provide in connection with switches, points and
signals on railways means to guard against accidents by trains being directed onto
the wrong lines and whereby the movement of the switches or points and signals
are so controlled that they cannot be wrongly set relatively to each other. Signals
connected with and operated by the switch or point mechanism are also provided
to indicate the position of the switches the said signals being so arranged in
connection with the switch or point operating mechanism that they are moved in
opposite directions to indicate the opposite positions of the switches or points and
so that the danger signal is displayed when the points or switches are not fully
home.
The signalling device may consist of two arms connected together at a short
distance apart to admit of a lamp being placed between them. These arms are
mounted so as to turn on or with a shaft or spindle carried in a suitable box or
frame and provided with a weight which tends to maintain the arms in a vertical
position. The arms are each provided with the necessary number of glasses
(usually three) arranged in the arc of a circle struck from the axis of the shaft or
spindle on which the arms are mounted through the centre of the bull's eye of the
lamp. The centre glass in each arm for danger (usually red) and the two outside
ones are respectively coloured to indicate the positions of the switch or point say
white and green or purple and green. These signal arms will generally most
conveniently only extend a short distance above the ground. To these arms is
connected, either above or below the axis on which they turn one end of a rod or
bar which is fitted to slide in suitable guides in a direction transverse to the line of
rails. Projecting from this rod or bar are two pins or projections against which
This lever is centred
one arm of a lever operated by the switch is caused to act.
at a short distance from a transverse bar which connects the pair of switch rails on
which transverse bar is a projecting stud or pin engaging in a slot in the short arm
of the said lever so that when the switch is moved the lever is caused to turn on its
centre and through its longer arm coming into contact with one or other of the pins
or projections on the bar or rod connected to the signal arms slide the said bar in
its guides and thereby turn the signal arms on their axis so as to indicate the
position of the switch. The signal arms are normally maintained by the counter
weight in the central or vertical position indicating in day light danger the red
glass shewing by night in like manner indicating danger. This position of the
arms is maintained while the switch is being moved from one position to the other
the pins in the rod or bar connecting the switch to the signal arms being so
arranged however that when the movement in either direction is nearly completed
the long arm of the lever comes into contact with one of these pins or projections
so that by completing the movement of the switch the said bar is caused to slide
and turn the signal arms on their axis so as to indicate in daylight by their
inclination and at night by the colour of the light brought opposite the lamp which
line is open. It will thus be seen that while the switch is partly open the danger
sigual remains and clearly shews to an approaching driver by day or night that the
signal is against him and when the switch is home the direction of inclination of
the arms or the colour of the light also clearly sheas the driver the position of the

page_text: said switch and in which direction his train will run. do not limit myself to the
foregoing details for example, instead of connecting the signal arms to a transverse
sliding rod or bar operated by a lever from the switch as hereinbefore described a
stud or stem projecting from the signal arms may enter a slot in a sliding plate
operated by the switch lever so as to alter the position of the arms according to
the position of the switch. This plate may be operated directly from the switch
lever or through the intervention of a rocking lever situated between the switch
rails and which moves, locks and unlocks the switch. Or the said plate may be
provided with an additional slot in which a stud from a link connected to the
switch rails engages whereby by the movement of the sliding plate the switch may
be moved over. The slots in this plate are partly parallel to and partly inclined
from the direction of motion of the plate the inclined portion of the one slot
effecting the movement of the switch and the inclined portions of the other slot
effecting the inclination of the signal arms. The slots are so arranged with
reference to each other that when the plate is moved by the switch lever to alter
the position of the switch, the pin in the link connected to the switch travels
along the inclined portion of the slot whilst the stud or projection from the signal
arms at the same time travels along the longitudinal portion of the other slot so
that the signal arms remain in the vertical or danger indicating position and
cannot be moved from this position while the switches are moving from one position
to the other. By the further movement of the switch lever in the same direction
after the switch is fully moved over or closed an inclined portion of the slot in
which the stud on the signal arms engages cause the said arms to turn on their
axis to an inclined position and so indicate the position of the switch, the longi-
tudinal portions of the slot in which the stud which operates the switch
works, permitting of this movement of the sliding plate without affecting the
switch. The handle or lever by which the locking and unlocking of the
switches is effected may be situated at a distance from the switches as in
grouped points or in a cabin and each lever may be made to control one switch
and two signal arms so that one line of rods and one lever may be employed to do
what usually requires two levers and two lines of rods. An improved controlling
device may be provided under the control of the station master or other responsible
person independent of the pointsman this device consisting of a plate baving two
longitudinal slots connected together at one of their ends by a transverse slot
thereby forming one continuous slot a portion of which is at right angles to the
other portions. In this slot a pin or projection from a link connected to the switch
rails engages so that when the transverse portion of the slot in the plate is in line
with the pin or projection the switch can be moved in either direction, but when
either of the longitudinal portions of the slot engage the pin or projection the
switch is locked and cannot be moved by the pointsman. This plate is connected
at one end by a rod or line of rods to a lever which, may be situated at a
considerable distance from the switch and which is under the control of a
responsible person independent of the man whose duty it is to operate the points so
that it is not possible for the pointsman to move the switch until the locking plate
is moved by the responsible person in charge of the operating lever into the
position to bring the transverse portion of the slot in the said plate opposite the
stud or pin on the bar or rod connected to the switch.
Connected to this sliding plate are rods or the like leading to signals which are
caused to indicate the position of the switch. These rods or the like are so
arranged and connected with the plate that only the proper signals can be given as
the longitudinal portions of the grooves being at opposite ends of the transverse
portion and in opposite directions will only allow the signals which correctly shew
the position of the switch to be operated.
Levers for operating facing end points and trailing end points in connection with
loop lines of single lines of rail may be so interlocked that they will move in such
manner as to ensure the trailing end point being first set and correctly locked for a
train to pass on either the main or loop line and then the facing end point

page_text: set and locked, and the facing end signal lowered for the line to which the
points are set so that a driver may know on which line he is to run and is
certain that the points at both the trailing and facing ends are properly set.
Each lever handle by which the switches are moved when situated at a distance
as in grouped points or in a cabin may be made to act as a detector or indicator to
show to the pointsman who operates the lever when there is an obstruction which
prevents the proper action of the switch. The first portion of the traverse of the
lever, before the switch commences to move, brings the signal arms into the
vertical or danger indicating position then by the further movement of the lever
the switch commences to move over but if there should be any obstruction to
movement of the switch the lever cannot be further traversed and will therefore
shew the pointsman that the switch is obstructed and meantime the danger signal
is given.
The points or switches may be operated either by rods as described or by
means of two chains or their equivalents connected to the opposite ends of the
slotted plate herein before described, the said chains or the like passing thence
over guide pulleys to the operating handle to which they are connected one on
each side of the centre on which the handle turns so that by the movement
of the handle the plate will be moved in one direction or the other according
to the direction in which the handle is moved and so change the position of the
switch.
Dated this 9th day of February 1894
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.
COMPLETE
SPECIFICATION.
Improvements connected with Railway Switches, Points, and
Signals.
I, EDWARD WALLER STONEY of the Chief Engineer's Office, Madras Railway
Company, Madras in the Indian Empire, Engineer, do hereby declare the nature
of this invention and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :-
My invention has for its object to provide in connection with switches, points
and signals on railways, means to guard against accidents, by trains being directed
onto the wrong lines and whereby the movement of the switches or points and
signals is so controlled that they cannot be wrongly set relatively to each other.
Signals connected with and operated by the switch or point mechanism are also
provided to indicate the position of the switches the said signals being so arranged
in connection with the switch or point operating mechanism that they are moved
in opposite directions to indicate the opposite positions of the switches or points
and so that the danger signal is displayed when the points or switches are not fully
home. My invention also comprises a detector signal and controlling device.
In order that my invention may be fully understood I will proceed to describe
the same with reference to the accompanying drawings:-
Figure 1 is a plan and Figure 2 an elevation of an indicator sigual constructed
according to my invention and arranged to be worked from the switch.
Figure 3 is a plan and Figure 4 an elevation of a sim.lar indicator signal
arranged to be worked direct from the switches by the stretcher bar prolonged.
Figure 5 is a plan and Figure 6 an elevation illustrating a modification in which
my indicator signal is operated by means of a slotted plate from the switch.
Figure 7 is a plan and Figure 8 an elevation illustrating another modification in
which my indicator signal is operated by means of a slotted plate which also
works and locks the switch.

page_text: cylindrical form.
Figure 13 is a diagrammatic plan illustrating my point detector and point and
signal controlling device and Figure 14 shows diagrammatically how such device
is applied to a main line and loop line.
Figure 13 shows the combination with the device represented in Figure 13 of
a slotted plate for enabling a station master to lock and control the points from a
distance.
Figure 14 is a plan illustrating a device for locking and detecting switches to
sidings.
Figures 15 to 20 show my improved means of interlocking the controlling levers
so that the trailing end points and signals must be set and locked in position before
the facing points can be moved.
The indicator signalling device consists preferably of two arms connected
together at a short distance apart to admit of a lamp being placed between them.
Referring to Figures 1 and 2'S S' are the arms; they are mounted so as to turn
with a shaft or spindle carried in a suitable box or frame B and are provided with
a weight W which tends to maintain the arms in a vertical position. The arms
are each provided with the necessary number of glasses (usually three) arranged in
the arc of a circle struck from the axis of the shaft or spindle on which the arms
are mounted, through the centre of the bull's eye of the lamp L. The centre
glass R in each arm is colored red to indicate danger and the two outside ones are
respectively colored conventionally to indicate the positions of the switch or point,
say white and green or purple and green. The signal arms S S¹ will generally most
conveniently only extend a short distance above the ground; especially if placed
in the six foot way. Where, however there is room to use a longer arm, such
arm can be made longer in which case it can be seen from a distance of say 600
or 700 yards. To enable the arm to be clearly seen by day at long distances
there can be placed between the arms a fixed screen or back ground painted white.
To the arms S S₁ is connected either above or below the axis on which they turn a
bar K by means of a rod r which passes through a hole in this bar through the
spindle of the arms and through the weight W. The bar K passes horizontally
through the box B and is connected to one end of a rod or bar E which is fitted to
slide in suitable guides G H in a direction transverse to the line of rails. Projecting
from this rod or bar E are two pins or projections ppl against which one arm of a
lever F operated by the switch is caused to act. This lever F is centred at D at
a short distance from a transverse bar A which connects the pair of switch rails.
On the transverse bar A is a projecting stud or pin P engaging in a slot C in the
short arm of the said lever F so that when the switch is moved the lever is caused
to turn on its centre D and through its longer arm coming into contact with one
or other of the pins or projections p p on the bar or rod E connected to the signal
arms to slide the said bar E in its guide and thereby turn the signal arms S Si on
their axis so as to indicate the position of the switch. The signal arms are
normally maintained by the counterweight W in the central or vertical danger
position indicating in day light danger; the red light showing by night and
indicating danger. This position of the arms S S' is maintained while the switch
is being moved from one stock rail or side to the other, the pins pp on the rod or
bar E being so arranged however that when the movement in either direction is
nearly completed the long arm of the lever F comes into contact with one of these
pins or projections so that by the completion of the movement of the switch the
bar E is caused to slide and turn the signal arms on their axis so as to indicate in
day-light by their inclination and at night by the color of the light brought
opposite the lamp, which line open. It will thus be seen that while the switch
is partly open the danger signal remains and clearly shows to an approaching
driver by day or night that the signal against him and when the switch is home
the direction of inclination of the arms or the color of the light also clearly shows
the driver the position of the said switch and in which direction his train will run.

page_text: I do not limit myself to the foregoing details, for example, instead of connecting
the signal arms S S¹ to a transverse sliding rod or bar operated by a lever from
the switch as herein before described, I prefer the arrangement next described.
According to this arrangement I provide a stud or stem H which projects from
the signal arms S S' as shown in Figures 3 and 4. This stud enters a slot I in a
sliding plate K operated by the switch lever, so as to alter the position of the
arms SS' according to the position of the switch. The plate K¹ may be operated
directly from the switch lever as illustrated in Figures 3 and 4 or through the
intervention of a rocking lever situated as illustrated in Figures 5 and 6 between
the switch rails and which moves, locks and unlocks the switch.
In the modification of my invention as illustrated in Figures 5 and 6 the weight W
previously mentioned is dispensed with and the three positions of the indicator
signal are effected by means of a pin on the signal arm working in a slotted plate;
which slotted plate is capable of being moved backwards and forward by suitable
mechanism connected with the switch.
The plate P is slotted horizontally in the centre. From each end of this
horizontal slot there is an inclined slot; these inclined slots running in the same
direction.
The signal arms S S¹ are provided with a pin or projection p situated at their
lower end. This pin or projection travels in the slot of the plate. This plate is
connected in any suitable way with the switch. In Figures 5 and 6 it is shewn
connected by the rod R with the tail piece T of the rocking mechanism which locks
and unlocks the switch. This locking arrangement forms no part of my present
invention.
Supposing that the pin p is at one end of the inclined slot the position of the
signal arm is also inclined. The first motion of the arm T in unlocking the switch
is to cause the pin p to travel along the inclined slot to the commencement of the
horizontal slot thereby causing the signal arm to assume the vertical or danger
position. The further motion of the arm T moves the switch completely from one
stock rail to the other stock rail and also causes the pin p to travel along the horizontal
slot; thereby locking the signal arms in their vertical or danger position.
The last motion of the arm T is to lock the switch and at the same time cause
the pin p to travel along the other inclined slot thereby causing the signal arm to
be inclined in the other direction.
The signal arm is thus at danger during the period that the switch is being
moved from one stock rail to the other and points to the open switch when home.
In the modification illustrated in Figures 7 and 8 in which the indicator signal is
operated by means of a slotted plate which also works and locks the switch the
said plate has in addition to the slot which operates the signal arms S S' a second slot
in which a stud from a link connected to the switch rails engages, whereby by the
movement of the sliding plate the switch may be unlocked, moved over and locked.
Pis the sliding plate a, b, c, d the slot that works the signal arms S S' and 1, 2, 3, 4
the slot that works the switches by means of a stud ✗ which engages in this slot
and is fixed to the link B which is in its turn connected to the bar A for working
the switches. The slots a, b, c, d and 1, 2, 3, 4 are partly parallel to and partly
inclined from the direction of motion of the plate P the inclined portion of the one
slot effecting the locking, unlocking and movement of the switch and the inclined
portions of the other slot effecting the motion and inclination of the signal arms.
These slots are so arranged with reference to each other that when the plate P is
moved by the switch lever to alter the position of the switch, the stud X in the
link B travels along the inclined portion of the slot 1, 2, 3, 4 whilst the stud or
projection E from the signal arms at the same time travels along the longitudinal
portion of the other slot a, b, c, d and vice versa so that the signal arms remain locked
in the vertical or danger indicating position and cannot be moved from this position
while the switches are moving from one stock rail or side to the other. By the
further movement of the switch lever in the same direction after the switch is
fully moved over or closed the switches are locked and an inclined portion of the

page_text: slot a bed in which the stud on the signal arms engages causes the said arms to turn
on their axis to an inclined position and so indicate the position of the switch, the
longitudinal portions of the slot 1 2 3 4 in which the stud which operates the
switch works permitting of this movement of the sliding plate. On the other hand
the switches cannot commence their movement in either direction until the indicator
arms have been moved to the danger position because in the first part of the move-
ment of the signal lever the stud that operates the switch moves in a longitudinal
part of its slot until the indicator arms by the action of an inclined portion of their
slot have been moved to danger.
Each lever handle by which the switches are moved when situated at a distance
as in grouped points or in a cabin acts as a detector or indicator to shew to the
person who operates the lever when there is an obstruction which prevents the
proper action of the switch. The first portion of the traverse of the lever before
the switch commences to move, unlocks them and brings the signal arms into the
vertical or danger indicating position, then by the further movement of the lever
the switch commences to move over but if there should be any obstruction to the
movement of the switch the lever cannot be further traversed and will therefore
shew the pointsman or signalman that the switch is obstructed and meantime the
danger signal is given.
A slotted sliding plate such as that shown at P in Figures 7 and 8 can in
addition to operating an indicator signal and moving and locking the switch as
already explained, be also made to work by means of one,set of rodding the main
and loop home signals by connecting to the said plate rods leading to these signals
as hereinafter described with reference to Figure 13; the slot for operating an
indicator signal can if desired be omitted from the plate in this combination.
Figures 9 to 12 inclusive show a modification of the last described device of a
plate furnished with a double slot for the purpose of actuating a switch and an
indicator signal. In this modification the plate in which the slots are situated is
cylindrical in lieu of being flat.
Figure 9 is a plan of this arrangement. Figure 10 is a section taken transversely
of the cylindrical plate. Figure 11 is a side elevation. Figure 12 represents a
development of the cylinder.
A is a frame on which is mounted a.cylinder B on an axle C. In this cylinder
are two spiral slots 1, 2, 3, 4 and a, b, c, d; the former works and locks the switches
and the latter the point indicator by means of pins P, Q, engaging in these slots,
the pin P projecting from the bar P' which works the switch; the pin Q projecting
from the bar Q which works the signal. As the bar Q' is superimposed on the
bar P the bar Q which is uppermost must be slotted as shown in Figure 11 to
allow the necessary movement of the pin P.
When I make the slotted plate of cylindrical form I prefer that the handle to
operate this plate shall be centred on the same axle C and pass through a hole in
the cylinder or be otherwise suitably fixed to the cylinder for example as shown in
Figure 10. Where desired a weight W may be attached to the handle.
The pins P and Q or the pin P only may be made hollow so as to shear across
in case the points are run through trailing if wrongly set, thus preventing the
switches or handle from being broken.
Another part of my invention consists in the combination and arrangement of
parts so constructed that each lever may be made to control one switch and two
signal arms and so that one line of rods and one lever may be employed to do what
usually requires two levers and two lines of rods. This part of my invention acts
also as an improved controlling device and may be placed under the control of the
station master or other responsible person independent of the pointsman. Figure 13
is a diagram in which this device is shown; it consists of a plate P having two
longitudinal slots connected together at their inner ends by a transverse slot
thereby forming one continuous slot a portion of which is at right angles to the
other portions. In this slot a pin or projection Q from a link connected to the
switch stretcher bar engages, so that when the transverse portion of the slot in

page_text: the plate is in line with this pin or projection the switch can be moved in either
direction, but when either of the longitudinal portions of the slot engages the pin
or projection, the switch is locked and cannot be moved by the pointsman. The
plate P is connected at one end by a rod or line of rods to a lever which may be
situated at a considerable distance from the switch as for example on the platform
near the station master's office or in any other place where it is under the control
of a responsible person independent of the man whose duty it is to operate the
points, so that it is not possible for the pointsman to move the switch until the
locking plate P is moved by the responsible person in charge of the controlling
lever into the position to bring the transverse portion of the slot in the said plate
opposite the stud or pin Q on the bar or rod connected to the switch. Connected
to this sliding plate are rods leading to the main home signal N and the loop home
signal M which are caused to indicate the position of the switch for the main and
loop lines respectively. These rods are so arranged and connected with the plate P
that only the proper signals can be given as the longitudinal portions of the
grooves being at opposite ends of the transverse portion and in opposite directions
will only allow the signals which correctly show the position of the switch to be
operated.
In Figure 13 the stud Q is shown as being opposite the transverse slot; and the
switch is in a position to be moved by the local pointsman; the signals accordingly
are both at danger. If the lever is pulled to the full extent in the direction of the
arrow the signal N will be lowered; whilst the signal M remains at danger.
On the other hand suppose that the switch was moved over so that the stud is at
the opposite end of the transverse slot. The signals in this case would again be
both at danger. If the lever is pushed to the full extent in the direction opposite
to the arrow the signal M will be lowered, whilst the signal N remains at
danger.
It will thus be seen that by my invention it is possible to detect and lock a point
and operate the two corresponding signals by one lever and set of rodding and that
only the signal which corresponds with the proper position of the points can be
moved, that is, main line when points are set for main line and loop line when
they are set for the loop siding.
In carrying out this part of my invention I adjust the connections between the
slotted plate P and the signals M and N in such a manner that the first movement
of the controlling lever or operating handle from its normal or vertical position.
whether in one direction or the other locks the points, but has no effect on the
signals. The object of this is to keep the switch locked when the lever is only
partly pulled over without affecting the signals. This device enables me to detect
and lock the trailing or going-out switches without lowering the corresponding
signals. The controlling lever has four positions in addition to the vertical or
normal position. These positions can be determined by a spring catch engaging in
suitable notches in the guides through which the lever works. When the lever is
in the vertical position the two signals are at danger, and the switch is capable of
being moved by the pointsman for shunting because the pin Q is in the transverse
part of the slot in the plate P. If the lever is moved to the next notch (whether
on one side or the other) the two signals remain at danger and the switch cannot
be moved. If the lever is moved to either of the extreme notches the switch is
locked and one of the two signals remains at danger whilst the other signal is
lowered depending upon the direction in which the lever or operating arm has been.
moved.
My invention can be usefully applied where the switches are worked locally,.
especially to ensure the safe working of trains through single line stations as the.
switches can be controlled detected and locked by the station master at a distance
from or near his office by means of levers, one lever being made to control one pair
of switches and to operate two signal arms as above described.
Where it is intended to work fast trains on a single line my invention should be.

page_text: applied to the outside switches at each end of the station; and the two controlling
levers or operating handles should be under the control of the stationmaster and
should be interlocked so as to compel the trailing end switches to be first set
correctly by the pointsman and then detected and locked by the stationmaster
operating the controlling lever, which then releases the controlling lever of the
facing points and allows this to be moved so as to lock the facing switches and
lower the corresponding home signal.
Figure 14 shows a single line passing a station having as is usual, a loop line
running in and out at the points V and W. These points are worked locally by
pointsmen by means of any description of handles, which actuate the rods v and w.
On each of these rods is a pin or projection Q which works in the slotted plate P
as before described. The controlling lever X works the apparatus connected with
the point V, whilst the controlling lever Y works the apparatus connected with
the point W. Each of the controlling levers X and Y has four positions in addition
to the vertical position as before described. These positions are numbered 1, 2, 3
and 4 in Figure 14, corresponding respectively with loop in, loop out, main out and
main in.
The following is the mode of operating the levers supposing it is desired to run
a through train from A to B.
The pointsmen must first set the switches correctly and the stationmaster then
moves the lever Y from its normal or vertical position to position No. 3. (If the
points be incorrectly set he cannot do so). This locks the trailing end point W
without lowering either of the two signals at W and prevents the pointsman from
moving them until Y is put back to its normal position. The station master next
moves the lever X to position No. 4 (which again he can only do if the switches are
correctly set). This locks the point at V (so that it cannot be moved until X is
put back again to its normal position) and also lowers one of the two signals,
namely the signal N which indicates to the engine driver that the switch is right
for the main line.
When once locked by the station master the pointsman locally actuating the
points cannot disturb the points until the station master so allows.
By this means the station master completely controls and locks two sets of points
and four signals by means of two levers and two lines of rods, and he is also able
to detect whether the switches have been set by the pointsman to the proper side
and are fully home. In case there should be an obstruction between the switch
and the stock rail, the pin Q does not traverse the full extent of the transverse slot
in the plate P and consequently the station master cannot pull over the controlling
lever.
The station master is thus kept informed as to the exact working of the switches.
If any such obstruction does occur the signal remains at danger.
When it is desired to allow shunting the station master places the levers ✗
and Y in their normal or vertical position; this puts all the four signals at danger
and brings the transverse slot of each slotted plate P opposite the pin or pro-
jection Q. The switches can then be moved freely from side to side for shunting
by the pointsmen.
The rods connecting the plate P and the controlling lever should be provided
with suitable compensators for temperature in the usual manner to ensure that the
locking plate P shall always come to the same position when the controlling lever
is moved.
Figure 13 shows an arrangement in which there is combined with the slotted
plate P Figure 13 another slotted plate the purpose of which is to allow the station
master by means of a lever at his office connected by two wires to the last mentioned
slotted plate at the facing points to control the pointsman, selecting for him the line
to be run over and signal to be lowered, and allow him to then set the points and
lower the corresponding signal, on doing which he locks the station master's lever.
This arrangement differs from the arrangement in Figure 13 in that in Figure 13

page_text: the local pointsman moves both the switch and the signals, whereas in Figure is no
moves the points only. The working is as follows;—
SL is a lever placed close to the station master's office, connected by two
wires wow fixed at equal distances from the axis in which this lever turns, and leḍ
on suitably placed pegs to the slotted plate p near the points; this can be moved so
as to bring any of the slots 1, 2, 3, 4 opposite the pin x by moving the lever S L to
notches at a bed respectively in its quadrant.
A plate P with a slot as in Figure 13 is placed at the points as previously
described and this is connected by rods R R with the main home. signal M
and loop home signal N; from it passes the rod r through the box in which
the plate p slides; on r is the pin x which engages in the slot of the plate p.
L is a lever by which the points:nan can move raud the plate P, after the plate p
is suitably set by the station master and the switches correspondingly set by
himself.
It will be seen that while the lever S L is in its normal or vertical position the
lever L cannot be moved by the pointsman who can only move the points from side
to side for shunting, the signals remaining locked at danger.
When the station master puts the lever S L in notch a, slot 1 plate p comes
opposite the pin x of the rod r, the pointsman sets his points to bring pin Qopposite
slot in P and moves the lever L to the right, which locks the points for the main
line and lowers the main line home signal, and locks the lever S L.
The short slots 2 and 3 are used when the points are run through trailing,
allowing them to be locked without lowering the signals; while the long slots 1
and 4 are used when the points are run over facing, so that they may be locked and
the corresponding signal lowered by the lever L and plate P when worked by the
pointsman.
The wires w w¹ being exactly the same length are equally effected by
temperature.
Instead of a plate p a cylinder may be used, in which case each wire w w¹ would
be wound one turn round each end of it.
It may happen that points belonging to sidings leading from the main line or
loop line are situated between the extreme facing points and to render running
through over these safe, it is necessary to detect and lock them in the correct
position for this purpose; this I do by means of a modification of the said
plate P.
Opposite the cross bar of each such points is placed a detector (Figure 14^)
having a sliding plate in which is formed a T-shaped slot a b c d worked by either
of the rods from the controlling levers to the outermost points directly or by cranks
as their situation requires. Through this works a slide fixed to the point cross-bar;
in this slide is a pin which passes through the slot a b. The sliding plate can only
be moved when this pin p is opposite that part of the slot a b, which only happens
if the points are correctly set for running through, and moving the controlling lever
either way locks them.
It is therefore clear that if such points are partly open or incorrectly set home, -
the controlling lever which detects and locks them cannot be moved, thereby
preventing the home and other signals from being moved. Further, the act of
moving the said controlling lever effectually locks the siding points. When this
controlling lever is in its normal or vertical position the cross slot c d is opposite p
and the points can therefore be moved freely to either side as may be required for
shunting.
C
The levers for controlling and operating the facing end points and corresponding
signals and trailing end points should he so interlocked that they will only move in
such manner as to ensure the trailing end point being first set and correctly locked.
What is the trailing end point when the train is running in one direction is the
facing end point when the train is running in the other direction hence a special
arrangement of levers and interlocking frame is necessary to ensure and compel the
trailing points to be first set. This can be effected in various ways but the simplest
B

page_text: way at present Know the and devised by me for erecting this is by means of the
arrangement shown in Figures 15 to 20.
Figure 15 shows the general arrangement of interlocking frame, the selecting bar
and selecting plates being removed.
Figure 16 is a plan of centre frame showing the selecting bar and plates in
place.
*
Figure 17 is an end elevation of frame.
Figure 18 shows the selecting bar and plates enlarged.
Figure 19 is a section on line A. B (Figure 18).
Figure 20 is a section on line C D (Figure 18).
1 to 7 represent lever plungers; No. being that of the controlling lever
for the down points and main and loop home signals; No. 2 of the controlling
lever for the up points and main and loop home signals; No. 3 of the up
starting signal; No. 4 of the down distant signal; No. 5 of the down starting
signal No. 6 of the up distant signal; and No. 7 of the selecting lever.
These lever plungers pass through a rectangular iron box the general arrange-
ment of which will be seen in Figure 15, the selecting bar and selecting
plates having been removed. There are placed at right angles to the plungers
tappet bars 8, 9, 10, 11 to which are fixed tappets which perform the necessary
locking. On the controlling lever plungers 1 and 2 are fixed the selecting
plates S S (Figures 16 and 18). Over the centre of these and at right angles to
them is the selecting bar E F worked by a pin a engaging in the slot V W formed
in the plunger bar 7 worked, by the selecting lever which traverses the bar E F in
guides G G, Figure 16, the latter being elongated to allow the bar E F to rise
into the dotted position E' F, Figure 17, and in this bar are fixed square studs P P¹
which engage in slots cut for them in the plates S S¹ Figures 19 and 20.
In each selecting plate is a transverse slot or groove ab c d and four longitudinal
slots ef gh ij klin S and mn op rs tu in St. These are formed in corresponding
pairs the one being long and the other short as (ef, mn) (gh, op) and (ij, rs)
(kl, tu), so that as the square studs P P₁ are brought opposite these pairs the
bars 1-2 can be moved in the same direction only, and the plate with the short
slot opposite a stud must be moved first.
The long slots are the same depth (about one-third the thickness of their plates)
throughout, while the bottoms of the short ones slope down inwards to the transverse
slot, being one-third depth of plate at their outside ends and two-thirds depth of
plate at their inner ends; the bottoms of the studs P and P' are just level with the
inner ends of the short slots g hij mn tu when the bar E F is down; so that if P
or P be brought opposite any of these the plates S S¹ can be drawn in the direction
this allows, and moving this plate raises the stud which enters the short slot, and
with it the bar E F, to the dotted position E¹ F.
This then brings the bottom of the other stud level with the bottom of its
corresponding long slot, so that its plate may be moved the full length of this.
It will thus be seen that although the studs P and P are opposite a pair of slots,
say ef, mn, plunger 1 cannot be moved because the bottom of the stud P is below
the bottom of the slot ef, and that plunger 2 must first be moved. so that P when
it reaches the end n has raised the bar E F, and with it P, high enough to allow it
to enter ef.
The position of the slots in the plates S S' on either side of the transverse one,
compels these plates to be moved in the same direction, either back or forward, for
main line, or loop line; while the inclined bottom of the shorter slots compels the
controlling lever belonging to the trailing end to be moved first, thus detecting and
locking that end.
The outer ends of the long slots correspond with the positions of the control
levers 1-2 in their outside or facing notches, while those of the short slots
correspond with the trailing end positions of the controlling levers 1-2.
A special lock is provided for 1 and 2 so that the one when in its outside notch
locks the other in its corresponding inner notch, and neither can be placed in its

page_text: outside notch till the other is first put in its inner notch. Spring catch or any
form of locking desired may be used for the interlocking of the levers with each
other.
The selecting lever and its bar E F has five positions, namely-shunting, as
shown in Figures 16 and 18;-main line up; main line down; loop line up; and
loop line down; in each of which the studs P and P are brought opposite the
correct corresponding slots, which enables the controlling levers 1 and 2 to be
moved as they should be, and then the other signal levers in order as required.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manuer the same is to be performed I declare that what I
claim is :-
1. An indicator signal device so arranged and operating as not only to indicate
the position of the points when set in either position but also to show the danger
position whilst the points are being moved or are partly open, substantially
as hereinbefore described and shown in Figures 1 to 4 of the accompanying
drawings.
2. The several arrangements or combinations of parts of indicator signal devices
and locking mechanism substantially as herein before described and shown in
Figures 5 to 12 of the accompanying drawings.
3. Operating and locking switches and indicator signals by means of two slots in
one plate substantially as hereinbefore described and shown in Figures 7 to 12 of
the accompanying drawings.
4. Operating signals by means of the slotted plate P Figures 13 and 14 whereby
one set of rodding detects and locks one set of points and operates the two
corresponding signals substantially as herein before described.
5. Operating signals and also controlling the switch by means of the slotted
plate P substantially as herein before described and illustrated in Figures 13
and 14.
6. The combination hereinbefore described in which a sliding slotted plate such
as that shown in Figures 7 and 8 (with or without the slot for operating an
indicator signal) by means of one set of rodding moves and locks the switch and
works the main and loop home signals as set forth.
7. The combination with the slotted plate P Figure 13 of another slotted plate
substantially as hereinbefore described and shown in Figure 13ª for the purpose
set forth.
8. The combination with mechanism such as claimed in Claim 4 of a plate formed
with a T-slot for locking and detecting switches to sidings substantially as herein-
before described and shown in Figure 14ª.
9. The combination of two slotted plates such as that referred to in Claim 5, the
signals that they respectively work at the two ends of a station, the switches that
they respectively control at those ends, the controlling levers that respectively work
the plates, and means of interlocking the levers in such a way that the trailing
points must be set and locked before the faciug points can be moved, substantially
as hereinbefore described.
10. The arrangement and combination of parts forming an interlocking frame so
arranged that the trailing points must be set and locked before the facing points
can be moved, substantially as hereinbefore described and shown in Figures 15 to 20
of the accompanying drawings.
Dated this 9th day of November 1894.
J. C. MEWBURN & ELLIS,
55 and 56, Chancery Lane, London, Patent Agents.