Improvements in or relating to Electric Signalling, particularly on Railways.
Year: 1897

page_text: Date of Application, 10th Dec., 1897
Complete Specification Left, 12th Sept., 1898-Accepted, 10th Dec.,
1898
PROVISIONAL SPECIFICATION.
Improvements in or relating to Electric Signalling, particularly on
Railways.
We, WILFRID SWANWICK BOULT, of 14, South Parade, Chelsea, in the County
of Middlesex, Electrical Engineer, and CEDRIC RANDAL. BOULT, of H11, Exchange
Buildings, Liverpool, in the County of Lancaster, Merchant, do hereby declare
the nature of this invention to be as follows;-
The object of this invention is primarily the extension and development of the
system of railway signalling described in Letters Patent previously granted to us
und numbered 17041 of 1893, 11773 of 1894, 2282 of 1895, 8724 of 1895, and
20735 of 1895; comprising a method of signalling on railways to or from moving
or standing trains by means of magnets acting on polarized needles or relays
for actuating indicators on "local circuits," and various other suitable apparatus.
Parts, however, of our present invention are applicable to other signalling
purposes.
The first part of our present invention has reference to the provision of a
repeater" for indicating to the signal cabin that a signal (and, if desired,
which signal) has been received on the train. This signal is conveyed to the
cabin by means of a local circuit and armature actuated by a magnet on the
train after the manner described in our above-mentioned Letters Patent. We
uso for our present purpose an electro-magnet on the train, and a polarised
needle (or needles) in the armature on the road. The ulectro-magnet on the
train may be of any suitable shape and when not energized will have no effect on
the road-armature but when energized will, according to its polarity deflect the
polarized needle to one side or the other and close a corresponding local circuit.
Any suitable form of signal indicator may be used in the cabin; but we prefer
that the well-known combination of pen and clock-driven drum shall be used
in conjunction with a bell. The two different signals may then be recorded, the
one by raising and the other by lowering the pen. In each case only a momen-
tary movement of the pen is needed. If the signals are not required to be
recorded, our indicator movement hereinafter described will be a suitable instru-
ment for giving the signal.
The energizing of the electro-magnet on the train is controlled by the signal-
indicator on the train as hereinafter described.
The second part of our invention relates to the construction of signal indicators
suitable for carrving on locomotive engines and capable of being actuated by
currents of very brief duration, and to a special movement for this purpose.
"
We will first describe the apparatus as applied to the moving of a miniature
semaphore between the two positions well-known as indicating danger" and
"line-clear" respectively. Mounted on a common iron base or yoke are two iron
cores and a permanent magnet, all three being by preference simple straight
bars or rods with their axes normal to the plane of the base. The magnet haa
pivotted to its onter end an iron or steel tongue or needle (by preference pivotted

page_text: through its centre of gravity) and is so placed that the tongue can swing between
the two cores or attached pole-pieces through an angle sufficient for actuating
the semaphore. We prefer that the tongue shall carry and swing the semaphore
round a centre at one end through an angle of 45°, but we may use any suitable
movement for producing this apparent effect to the eye of the observer, as for
instance by two semaphores (one in each position) moved alternately into and
out of view, or otherwise.
Each of the two cores carries an independent coil, and movement of the tongue
between the two cores is produced not as in a telegraph polarized relay by revers-
ing a current through the two coils but by sending a current (in each case always 1
in the same direction) through the more distant coil alone, the core of the inactivo
coil being by induction rendered repellent of the tongue whilst the more distant
core of the active coil is strongly attractive. For instance, if the outer end of
the magnet (and therefore of the tongue) is north, the core against (or near)
which the tongue is lying (when no current is passing) will by induction from the
permanent magnet be magnetized with reverse polarity, or with its outer end
south, the tongue being attracted to it just as in the ordinary polarized relay.
To throw the tongue over to the other core this latter is magnetized by its coil
with its outer end south, two magnetic circuits being thus established, viz.
(a) down the energized core, through the yoke, up the permanent magnet (which
is thereby strengthened), into the tongue, and across the air-gap to the outer end
of the core again, the tongue being thus strongly attracted, and (b) a parallel
circuit down the same core and up the unenergized one, the polarity of which is
then reversed so that its outer end becomes north and repels the north pole of the
tongue at the same time that the energized core attracts it.
This movement (which is very suitable as & bell-indicator with electric replace-
ment, for turning inaccessible gas-laps for sigualling, and for other signalling
purposes) may be modified in form without departing from the spirit of our
invention; thus, a magnetized steel tongue may be used pivotted to an iron post
or direct to the base or yoke; or the tongue need not be permanently polarized
at all. In the last case however it will not be attracted to a core when no current
We have found practically that with this method of simple-coil working
one Leclanché or "dry" cell applied to a small coil can (if it is not allowed to
quite touch the repelling core) throw the tongue over through 45° or more with
great speed and certainty, even though acting against the force of gravity on
& unbalanced tongue.
is on.
In cases where it is desired that the tongue shall take up a central position
when no current is flowing and be deflected to one side or the other by current,
we place on the base a third iron post to which we pivot un iron tongue so that
when no current is flowing its free end is attracted to the magnet (to which no
tongue is pivotted) and at the same time repelled from both sides by the similar
induced poles of the cores. If now one of the coils be energized with its outer
end south, the iron post the other core and the magnet will all be similarly
polarized, and the last two will repel the tongue towards the energized coil which
is at the same time attracting it. On cessation of current, the tongue will again
swing round towards the permanent magnet.
In connection with our aforesaid magnetic system of signalling we may employ
two indicators to show if the two needles in the armature have closed their respec-
tive circuits on each occasion. These needle-indicators may couveniently bo
worked similarly to the semaphore just described (though there is no occasion
for the tongue to move through nearly so large an angle as 45°), but arranged so
as to show say a red spot when the signal current energizes one coil and to
replace this spot out of sight behind the dial of the instrument when the observer
sends a current through the other coil by pressing a "push or otherwise. It is
not essential that the needle indicators shall be reserved for needle-indicating
only; thus the " spot" indicators just described might be used as signal indi-
cators also, or two semaphores might be independently actuated by the two
"

page_text: needles respectively, or various other combinations might be arranged. The
object in view is not solely, as mentioned in our previous Specification No. 11773
of 1894, to render total failure highly improbable, but to provide a "fault"
signal so that while the running signals are given correctly it may be instantly
known if only one of the two needles is making contact.
If the engine (or vehicle) carries two armatures-one for taking distant and
the other home siguals, the distant and home semaphores and four needle-
indicators may conveniently all be arranged on the same iron base, three replacing
coils only being employed in connection with the six polarized tongues.
call
To prevent the possibility of the replacing current interfering with the receipt
of a signal, we may employ a special replacer push through a coil in which the
signal current always passes energizing a magnet which breaks the replacing
circuit if it is at the time closed. The signal current may also be arranged
to act much more strongly than the replacing current, and it thus
very quickly give the signal even when it finds the replacing current
Another advantage of having the signal current act more strongly than the
replacing current is that so long as the battery is strong enough to replace there
is a good margin of power for the signal and attention must be called to a failing
battery in good time. To remake the replacing circuit it is necessary to release
the push and again press.
on.
61
The working of the semaphore may be on different plans. For instance it
may always stand as left by the last signal current, remaining as a record of that
signal and requiring no replacement, or home and distant-signals may replace
each other, or the signal may be always replaced out of sight by a push or other-
wise, or it may always be replaced (or held) in the danger" position, this
being equivalent to line-closed" not danger" until at least one needle-
indicator shows or a bell rings. Ringing the bell may be conveniently effected
by making the tongues of the needle-indicators act as circuit closers for this
purpose. The same contacts may also close either through similar contacts on the
semaphore tongues or not, as required or arranged, the current of the
repeater electro-magnet above described. Instead of using the two
circuits from the repeating armature on the road for giving both danger and line-
clear repeats, we may use one circuit for the danger repeat and the other for a
clearing signal actualed by a magnet carried by the tail vehicle of a train, this
signal serving to show beyond doubt that the whole train has passed.
Or we may repeat both danger and line-clear signals and let the tail magnet give
a second sigual (for instance line clear) to stand for the clearing signal.
For the purpose of a train-describer, a station-indicator on a train, a ship's or
ABC telegraph instrument, &c. we construct the indicator with a magnet and
tongue in the centre and a ring or segment of coils round it. The transmitter for
use with this indicator will be in the form of a radial switch in general arrange-
ment very like a common form of accumulator or variable resistance switch. The
radial arm will when left in any position be lifted clear of the contact-plate by
a spring, but so arranged that it can be turned only when pressed down so as to
make contacts. A dash-pot or equivalent may be placed to prevent the arm from
rising and breaking circuit before the indicating needle has had time to conte to
rest.
Each contact-plate will be connected by a special wire with a corresponding
coil on the receiving instrument. A common wire or earth may be used for the
return current. The battery may be inserted in any well-known way. This
apparatus will work when turned in either direction, and the only moving parts
are the switch arm turned by hand at one end of the line and the pivotted needle
at the other end.
Another improvement in our system is the substitution in the armature for the
pivotted needles of polarized spring tongues which answer the double purpose
of contact-maker and controller; the normal or relaxed position of the tongues
being the middle or neutral position, clear of both contact-posts.
Another improvement in combining two or more armatures into one compound

page_text: structure so that the longitudinal pole-plates (except the two outside ones) serve
each for two sets of armature needles. Thus, four longitudinal plates give three
intermediate spaces or bays in each of which a divided bridge and needles may
be placed.
For indicating which route is "made" we may use the following arrangement.
Wherever it is arranged to give the information, as for instance near the distant
sigual, we place electro-magnets on the road to operate special armature needles
in the usual manner. Each circuit closed by one of these needles operates a
numbered signal-one of the "spot" movements described above being suitable
for the purpose.
If three such movements are employed, and numbered respectively 1, 2, M³,
No. 1 being governed by ono armature (the other circuit from which may be other-
wise utilized) and Nos. 2 and M³ by another armature, the following route numbers
may be given :-

page_text: Improvements in or relating to Electric Signalling, particularly on
Railways.
We, WILFRID SWANWICK BOULT, formerly of 14, South Parade, Chelsea, but now
of Sudbury, Beechcroft Road, Upper Tooting, in the County of Middlesex, Elec-
trical Engineer, and CEDRIC RANDAL BOULT, of HII, Exchange Buildings, Liverpool,
in the County of Lancaster, Merchant, do hereby declare the nature of this inven-
tion and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement:-
The object of this invention is primarily the extension and development of the
system of railway signalling described in Letters Patent previously granted to us
and numbered 17041 of 1893, 11773 of 1894, 2282 of 1895, 8724 of 1895, and
20735 of 1895; comprising a method of signalling on railways to or from moving
or standing trains by means of magnets acting on polarised needles or relays
for actuating indicators on local circuits," and various other suitable apparatus.
Parts, however, of our present invention are applicable to other signalling
purposes.
"
"
The first part of our present invention has reference to the provision of a
repeater" for indicating to the sigual cabin that a signal (and, if desired,
which signul) has been received on the train. This signal is conveyed to the
cabin by means of a local circuit and armature actuated by a magnet on the
train after the manner described in our above-mentioned Letters Patent. We
use for our present purpose an electro-magnet on the train, and a polarized
needle (or needles) in the armature on the road. The electro-magnet on the
train may be of any suitable shape and when not energized will have no effect on
the road-armature, but when energized will, according to its polarity deflect the
polarized needle to one side or the other and close a corresponding local circuit.
Any suitable form of signal indicator may be used in the cabin; but we prefer
that the well-known combination of pen and clock-driven drum shall be used
in conjunction with a bell. The two different signals may then be recorded, the
one by raising and the other by lowering the pen. In each case only a momen-
tary movement of the pen is needed. If the signals are not required to be
recorded, our indicator movement hereinafter described will be a suitable instru-
ment for giving the signal.
The energizing of the electro-magnet on the train is controlled by the signal-
indicator on the train as hereinafter described.
The second part of our invention relates to the construction of signal indicators
suitable for carrying on locomotive engines and capable of being actuated by
currents of very brief duration, and to a special movement for this purpose.
"
We will first describe the apparatus as applied to the moving of a miniature
semaphore between the two positions well-known as indicating
danger" and
"line-clear" respectively. Mounted on a common iron base or yoke are two iron
cores and a permanent magnet, all three being by preferonce simple straight
bars or rods with their axes normal to the plane of the base. The magnet has
pivotted to its outer end an iron or steel tongue or needle (by preference pivotted
through its centre of gravity) and is so placed that the tongue can swing between
the two cores or attached pole-pieces through an angle sufficient for actuating
the semaphore. We prefer that the tongue shall carry and swing the semaphore
round a centre at one end through an angle of 45°, but we may use any suitable
movement for producing this apparent effect to the eye of the observer, as for
instance by two semaphores (one in each position) moved alternately into and
out of view, or otherwise.

page_text: Each of the two cores carries an independent coil, and movement of the tongue
between the two cores is produced not as in a telegraph polarized relay by revers-
ing a current through the two coils but by sending a current (in each case always
in the same direction) through the more distant coil alone, the core of the inactive
coil being by induction rendered repellent of the tongue whilst the more distant
core of the active coil is strongly attractive. For instance, if the outer end of
the magnet (and therefore of the tongue) is north the core against (or near)
which the tongue is lying (when no current is passing) will by induction from the
permanent magnet he magnetized with reverse polarity, or with its outer end
south, the tongue being attracted to it just as in the ordinary polarised relay.
To throw the tongue over to the other core this latter is magnetized by its coil
with its outer end south, two magnetic circuits being thus established, namely,
(a) down the energised coil through the yoke, up the permanent magnet (which
is thereby strengthened), into the tongue, and across the air-gap to the outer end
of the core again, the tongue being thus strongly attracted, and (b) a parallel
circuit down the same core and up the unenergised one, the polarity of which is
then reversed so that its outer end becomes north and repels the north pole of the
tongue at the same time that the energised core attracts it.
This movement (which is very suitable as & bell-indicator with electric replace-
ment, for turning inaccessible gas-taps for signalling, and for other signalling
purposes) may be modified in form without departing from the spirit of our
invention; thus a magnetized steel tongue may be used pivotted to an iron post
or direct to the buse or yoke; or the tongue need not be permanently polarized
at all. In the last case however it will not be attracted to a core when no current
is on. We have found practically that with this method of single coil working
a movement of the tongue approaching 90° can readily be obtained and we
believe this could be considerably extended.
In cases where it is desired that the tongue shall take up a central position
when no current is flowing and be deflected to one side or the other by current,
we place on the base a third iron post to which we pivot an iron tongue so that
when no current is flowing its free end is attracted to the muguet (to which no
tongue is pivotted) and at the same time repelled from both sides by the similar
induced poles of the cores. If now one of the coils be energized with its outer
end south, the iron post, the other core and the magnet will all be similarly
polarized, and the last two will repel the tongue towards the energized coil which
it at the same time attracting it. Un cessation of current, the tongue will again
swing round towards the permanent magnet.
"
In connection with our aforesaid magnetic system of signalling we may employ
two indicators to show if the two needles in the armature have closed their respec-
tive circuits on each occasion. These needle-indicators may conveniently bo
worked similarly to the semaphore just described (though there is no occasion
for the tongue to move through nearly so large an angle as 45°), but arranged so
as to show say a red spot when the signal current energizes one coil and to
replace this spot out of sight behind the dial of the instrument when the observer
sends a current through the other coil by pressing a "push or otherwise. It is
not essential that the needle indicators shall be reserved for needle-indicating
only thus the "spot" indicators just described might be used as signal indi
cators also, or two semaphores might be independently actuated by the two
needles respectively, or various other combinations might be arranged. The
object in view is not solely, as mentioned in our previous Specification No. 1177:3
of 1894, to render total failure highly improbable, but to provide a "fault
signal so that while the running signals are given correctly it may be instantly
known if only one of the two needles is making contact.
:
"
If the engine (or vehicle) carries two armatures-one for taking distant and
the other home signals,-the distant and home semaphores and four needle-
indicators may conveniently all be arranged on the same iron base, three replacing
coils only being employed in connection with the six polarized tongues.
To prevent the possibility of the replacing current interfering with the receipt

page_text: when it
of a signal, we may employ a special replacer push through a coil in which the
signal current always passes energizing a magnet which breaks the replacing
circuit if it is at the time closed. The signal current may also be arranged
to act much more strongly than the replacing current, and it thus can
very quickly give the signal even
finds the replacing current
Another advantage of having the signal current act more strongly than the
replacing current is that so long as the battery is strong enough to replace there
is a good margin of power for the signal and attention must be called to a failing
battery in good time. To remake the replacing circuit it is necessary to replace
the push and again press.
on.
The working of the semaphore may be on different plans. For instance it
may always stand as left by the last signal current, remaining as a record of that
signal and requiring no replacement, or home and distant-signals may replace
each other, or the signal may be always replaced out of sight by a push or other-
wise, or it may always be replaced (or held) in the dangen" position, thus
being equivalent to "line-closed" not "danger" until at least one needle-
indicator shows or a bell rings. Ringing the hell may be conveniently effected
by making the tongues of the needle-indicators act as circuit closers for this
purpose. The same contacts may also close either through similar contacts on the
semaphore tongues ог not, as required or arranged, the
the electro-magnet above described. Instead of using the two circuits
from the repeating armature on the road for giving both danger and line-
clear repeats, we may use one circuit for the danger repeat and the other for a
clearing signal actuated by a magnet carried by the tail vehicle of a train, this
signal serving to show beyond doubt that the whole train has passed.
current of
Or we may repeat both danger and line-clear signals and let the tail magnet give
a second signal (for instance line clear) to stand for the clearing signal.
For the purpose of a train-describer, a station-indicator on a train, a ship's or
A B C telegraph instrument, &c. we construct the indicator with a magnet and
tongue in the centre and a ring or segment of coils round it. The transmitter for
use with this indicator will be in the form of a radial switch in general arrange-
ment very like a common form of accumulator or variable resistance switch. The
radial arm will when left in any position be lifted clear of the contact-plate by
a spring, but so arranged that it can be turned only when pressed down so as to
make contacts. A dash-pot or equivalent may be placed to prevent the arm from
rising and breaking circuit before the indicating needle has had time to come to
rest. Each contact plate will be connected by a special wire with a corresponding
coil on the receiving instrument. A common wire or earth may be used for the
return current. The battery may be inserted in any well-known way. This
apparatus will work when turned in either direction, and the only moving parts
are the switch arm turned by hand at one end of the line and the pivotted needle
at the other end. Another improvement in our system is the aubstitution in the
armature for the pivotted needles of polarised spring tongues which answer the
double purpose of contact maker and controller; the normal or relaxed position
of the tongues being the middle or neutral position, clear of both contact-posts.
Another improvement is combining two or more armatures into one compound
structure so that the longitudinal pole-plates (except the two outside ones) serve
each for two sets of armature needles. Thus, four longitudinal plates give three
intermediate spaces or bays in each of which a divided bridge and needles may
be placed..
"
For indicating which route is "made we may use the following arrangement.
Wherever it is arranged to give the information, as for instance near the distant
signal, we place electro-magnets on the road to operate special armature needles
in the usual manner. Each circuit closed by one of these needles operates n
numbered signal-one of the "spot" movements described above being suitable
for the purpose:
If three such movements are employed, and numbered respectively 1, 2, M,

page_text: No. 1 being governed by one armature (the other circuit from which may be other-
wise utilised) and New. and M² by another armature, the following route numbere
may be given
1
may be given;-
Ram Jine = M°
1 = 1
= 2
One electro-magnet to each armature.
3 = 1 + 2
4=1+ Ms
5 == 2+ Ma
61+2+M8
}}
A second electro-magnet to the double-number armature.
This system of indicating routes by combinations of numbers is applicable to
other systems of signalling than our magnetic one. Circuits for energizing the
electro-magnets (or other equivalent arrangements according to the system of
signalling adopted) may be automatically controlled by the existing interlocked
levers.
"
Instead of the system of "mixed magnets
described in our Specification
No. 2282 of 1895, we may use the following arrangement which for distinction we
call "separate magnets.'
On this system, at every signal position we place first a set of fixed permanent
magnets which always give the danger signal. Closely following these by pre-
ference at an interval of a few yards are fixed electro-magnets which when energised
(always with the same polarity viz. opposite to that of the danger magnets) at once
reverse the signal to line-clear. When not energised, the electro-magnets have no
effect and the danger signal remains.
As a means of re-invigorating the permanent road-magnets from time to time,
we prefer to use an electro-magnet carried by a trolley to be pushed along the
line, the poles of the electro-maguet passing close to those of the road-magnets.
As a convenient means of getting very close, we prefer that the electro-maguet
shall be supported on springs and carry iron rollers or wheels attached to its poles;
the level at which the electro-magnet is hung to the trolley being
adjusted that when passing over the road-maguets the rollers shall bear lightly
on the cover of the road-magnets, or, if this is removed, on the ends of the magnets.
Instead of rollers on the poles, we may use iron wire brushes, springs, or other
flexible devices to drag over the ends of the road-magnets.
80
Instead of using" separate magnets," or any of the devices disclosed in our previous
Letters Patent, for manipulating the road-magnets, we may effect the control of the
signal at each position by reversing the polarity of fixed permanent magnets
forming the cores of electro-magnets in the coils of which the current may be
reversed. As compared with separate magnets a heavy current will be required
and will be necessary for both signals, but in each case its duration need only
be momentary. This arrangement we call for distinction that of "compound
magnets.'
"
The accompanying drawings illustrate by way of example constructions of
apparatus containing improvements according to this invention.
Figure 1 is a diagrammatic view of the signal receiving and indicating apparatus
carried by the train showing the electric interconnection of the parts.
Figures 2, 3 and 4 show in diagram three alternative constructions of "polarised"
"movement" or relay.
Figures 5 and 6 are plan and elevation respectively of one arrangement of indi-
cating apparatus for use on the engine embodying polarised movement.
Figure 7 is an elevation of a "replacer push" according to this invention with
the cover removed and
Figures 8 and 9 are plan and elevation of the same, the cover being on in
Fig. 8, the elevation, Figure 9, being a view of Figure 8 when looking in the
direction of the arrow 9.
Figure 10 is a plan of a "compound armature."

page_text: Figure 11 is a cross section of the armature shown in Figure 10 when in position
over an electromagnet in the track.
Figure 12 is a side elevation of the parts shown in Figure 11.
Figure 13 comprises plan, side elevation and enlarged detail view showing
one construction of track electromagnet.
Figure 14 is a side elevation, and
Figure 15 a cross section of one arrangement of track permanent magnet
and support therefor.
Figure 16 is a perspective view showing the application of a polarised movement
according to this invention to the construction of an A.B.C." telegraphing
apparatus.
With reference first to Figure 1, the needles of the three armatures carried by the
train are shown at A, A1 and A2 respectively, A being intended to receive say the
distant danger signals, A. the home signals and As the other two route signals.
The coils which these needles energise when giving the danger signal or its
equivalent are shown at B, B and B respectively, an additional pair of coils B³
being also energised when a danger signal is given and serving to call into view
the spots" which serve to indicate that both needles of the armature have worked.
An electric bell C is shown which is started ringing automatically by the action
of the coils B, the tongues e which they operate serving to close the circuit
through insulated contacts upon the cores of the coils B3 indicated in Figure 1
by the circles B.
The contacts in connection with the said coils B, B' B2 and B3 with which the
armature needles make contact are indicated at band. The method of connect-
ing the electric circuits for these coils will be hereinafter explained more fully.
E, E, E and E are the pillars or permanent magnets of the polarised move-
ment the action of which is hereinafter more fully explained and the tongues e, el, e
and are the movable parts which serve to produce a visual signal; in Figure 1
they are all shown in a position midway between the two extremes although in
practice they always remain adhering by magnetic attraction to one or the other
of the two electromagnet cores which serve to operate them. F indicates a replacing
push and G the batteries which are called into action by the needles A, A and A¹.
The batteries G are provided in duplicate in order to minimise the risk of a
breakdown and portions are held in reserve to be switched in if necessary to
increase the battery power in the event of the main portion G becoming run down.
Gare resistances inserted in the battery circuits to ensure a sufficient current
passing from the good battery through its coils B3 in the event of a short circuit
in the other battery which would tend to take so much current as to prevent the
coil from receiving sufficient to operate it.
His an electromagnet the circuit of which is automatically closed through
either or both of the longues e when the latter are operated by the receipt of a
danger signal. This electromagnet is intended to operate the needles of an
armature placed in a track over which the train carries the magnet H the arma-
ture needles H serving to complete circuits from a battery H through the signal
receiving device H in the signal cabin, the return circuit being indicated through
earth.
I, are the terminals of the indicator and I is a connection to frame or to earth
through which the circuit of the bell C and the circuit of the magnet H are
closed.
With reference to the connections and operations of the apparatus shown in
diagram in Figure 1 they are as follows:-
Starting with the armuture A when the two needles are deflected by the road
magnets so as to make contact with the two points b, the current will take the
following course. That leaving the left-hand battery G by its positive pole will
traverse the resistance G, the left-hand coil 133 leaving which it passes to the
right and unites with the current (the course of which is subsequently to be
described) coming from the right-hand coil B³, pusses upwards through the coil Ba
n

page_text: away to the left through the coil B to the two right-hand terminals of the left
group where it divides, passes downwards to the two contacts b through the two
needle pivots partly to the left-hand battery G and partly to the right-hand.
The current from the right-hand battery G follows a similar course by traversing
the right-hand resistance G and the right-hand coil B before uniting with the
current from the left-hand coil 133. The course of the two united currents has
just been described. In this and the following description of the course of the
various currents, the terms "right" and "left" and "up" and "down" will be
employed with reference to the diagram given in Figure 1, and will not in any
way imply such direction in the actual apparatus on the engine.
The effect of the two currents flowing along the circuit closed through the
contacts is as follows:-
The excitation by them of the two coils B pulls over their respec-
tive tongues into contact with their respective cores and the
subsequent joint passage of the two currents through the coil 1 is to
attract to its core both the tongues ; leaving the coil they excite the coil B
and attract to this core the tongue c. In the diagram shown there is but one
circuit through the coil B and through the coil B and the two currents thus
traverse the sume conductor as one current, but if preferred two separate windings
may be employed on these coils and indeed the whole circuit from the coils B³
to the terminals I may be duplicated and the currents kept separate as before
stated.
The tongues when pulled over by the coils B3 put the insulated contacts 13'
in connection with the frame through the pillars E and thereby close a circuit
from the right-hand battery and the bell through the frame of the machine,
one terminal of the bell being connected at 1' to the frame. As long therefore
as the tongues are against the contacts B1 the bell C will continue to ring and
draw the attention of say the driver to the spots or other signals which the move-
ment of the tongues has brought into view. The attraction of the tongues
and the tongued by the coils B and B respectively causes the route signals,
which before were showing to disappear and the apparatus therefore remains
with the two spot or other distant danger signals alone showing and the bell ringing.
In order to put a stop to the bell, the circuits through the push F may be closed
and this will allow a current to pass through the left-hand battery through the
coil D. This current causes the tongues e to fly towards the core of the coil D³,
thus breaking the bell circuit and replacing the signals exhibited by the tongues.
The above described operations may constitute a distant danger signal together
with the manual replacing or cancelling of such sigual.
If the road magnets are set so as to give "line clear" at the distant station
the needles of the armature A will be deflected against the contacts and will
in that position close circuit from the two batteries through the coil D, and the
coil 3. This action pulls the tongue against the core of the coil D and the
tongues against the core of the coil D; the former movement may serve to
at once indicate "line clear" at distant station and a route, and the latter action
will stop the bell if it is ringing and will cause the spots or other distant danger
siguals if they are showing to be cancelled.
The action in connection with the home armatures A' is of a similar character
to that already described with reference to the armature A. Contact between
the home needles and the points b' will close circuits which can be readily traced
on the diagram through the coil B', both the coils B³, the two batteries and the
two needles; the coil 131 by attracting the tongue el gives the home danger signal
and the coils B³ as before cause say the spots to be shown and start the bell
ringing. These signals may again be cancelled by depressing the push F. On
the other hand contact between the home needles and the contacts allows current
to pass through the coils I) and D³, the two batteries and the needles in succes-
sion, the coil D' giving the home line clear signal and the coil D³ as before
replacing the spots and stopping the bell.
As regards the armature As the circuit connected with the contacts
includes

page_text: the coil D, the coil D³ and both the batteries. This gives the replacement of the
spots if they were showing and stoppage of the bell, and the appearance of a
sigual carried by the left-hand tongue which corresponds with one of the routes.
Current through the contacts d traverses the coils D and Ds, the effect of the
coil on the right-hand tongue being employed to indicate another route.
From the foregoing it would be observed that the spots or other signal carried
by the tongues are shown and the bell is set ringing for every danger signal
and the receipt of a line clear signal from either the distant, the home or the
route armature cancels the spots and stops the bell. It will be noted that a
route signal is regarded in this particular scheme shown in Figure 1 as equivalent
to a distant line clear signal.
The electro magnet H has one terminal connected to the point I' which is in
connection with the frame of the instrument and the other as will readily be
traced on the diagram connected to the negative pole of the right-hand battery;
it is thus in parallel with the bell and is excited at such times as the bell is ring-
ing, that is to say after the receipt of every danger signal. It may when energized
be employed to act upon an armature placed in the roadway in order to repeat or
acknowledge to the signal cabin the receipt of a danger signal. An armature for
this purpose
is indicated at II', the battery at II, and a signal cabin instrument
at H³, the circuits of this portion being arranged in a similar manner to those
already described and needing therefore no explanation as they are readily intel-
ligible by reference to the diagram. By moving the switches G³ from the
contacts to the contacts (5, the reserving portion G' of the two batteries may
be switched either separately or simultaneously into the circuits in the event of
the main portions G having become enfeebled.
In Figures 2, 3 and 4 are shown in diagram alternative constructions of u
"polarized movement" according to this invention. By movement is meant the
mechanism which serves either to complete a local circuit as in a relay or lo
operate a visual signal or other device.
Upon a suitable base of magnetic material preferably iron is mounted a
pillar K, pivotally connected to the upper end of which is a tongue K. K are
coils to the cores K³ to which the tongue K' may alternately be attracted. Tha
diagrams Figures 2 and 4 are substantially plan views. Either the pillar K or
the tongue or both may be permanently magnetised but in the case of only
one being permanently magnetised the other must be of nagnetic material;
that is if the tongue bo magnetised the pillar K is made of magnetic material that
is to say of iron, steel, or possibly of nickel or cobalt. If the pillar K is a magnet
the tongue K may itself be a permanent magnet or may be of soft iron or other
magnetic material.
The tongue being in contact with or nearly touching one of the cores K³
it will adhere thereto by reason of its magnetism and if the other of the two
coils KB be now energised so that the polarity of its upper end be opposite to that
of the moving end of the tongue K the flux due to this coil will pass through
the base and, dividing, up through the pillar K out to the end of the tongue K¹
and also up the core with which the tongue K' is in contact. The core and the
tongue thereupon become mutually repulsive whereas the tongue experiences
attraction towards the other core to which it therefore flies and remains in contact
therewith owing to residual or permanent magnetism.
It is not necessary either that the pillar K or that the tongue K' should be
permanently magnetised as sufficient magnetism may be induced in them by
means of the coils but if either or both are permanently magnetised the mag-
netism due to the coils may obviously be always of that polarity which will tend
to strengthen the pillar K or tongue K. To operate this movement " it is
obviously only necessary to energise one coil K at a time, the alternate energising
of these coils causing the tongue to fly back and forth between them.
In the modification shown in Figure 3 the tongue is pivotted centrally.
In the modification shown in Figure 4 the tongue is shown mounted on an iron
or similar pillar K a permanent magnet K being provided which serves to keep

page_text: the tongue K in a position midway between the two coils K from which position
it may be deflected by either coil but to which position it will return upon cessa-
tion of the current in the coil.
Figs. 5 and 6 illustrate one form of indicator by which the signals received by
the armatures are conveyed to say the engine driver. Upon an iron base are
mounted six pillars and pivotted tongues, and coils by which the tongues are
operated to form polarised movements of the kind already described with reference
to Figure 2. J is the coil by which the home semaphore arms J8 is raised to the
danger position, J' being the coil by which it is lowered. J and J³ are the coils
for performing the same functions respectively for the distant semaphore arm Jº.
Jare the coils by which the spots are operated which indicate that both needles
of the home armature have worked and the coils J perform a similar function
with regard to the needles of the distant armature, and its two spots J. In
all these movements the pivotted tongues are shown dotted underneath the sema-
phore and spot arms respectively. Between the coils J and J³ on one side is a
single replacing coil J which serves to simultaneously replace at one operation
both the home and distant spots on that side. The same arrangement is adopted
on the other side where another coil Jo intermediate of the coils J and J on that
side serves to replace both tongues, that is to say both spots. 10 are contacts
indicated diagrammatically at Figure 1 carried at the top of the cores of the
magnets and J³ insulated therefrom, but connected with the bell and mag-
net II, Figure 1. When the respective tongues complete circuit through these
contact pieces J10, the bell is set ringing and the magnet H is energized. In
the sectional view shown in Figure 6 the apparatus is shown enclosed in a brass
case J¹¹ with
glass front, the method of making contact with the various
coils being shown by a spring J in the base of the instrument.
Figures 7, 8 and 9 illustrate cne construction of replacer push. Upon a
buse Lis mounted a magnet L' carrying at one end a pivotted tongue L. One end
of this tongue plays between one end of an iron bar L³ and the core of an electro-
magnet L
A hinged lever L3 preferably of non-magnetic material such as brass,
is provided with a push button L, and at the end adjacent to the tongue L³
with a hook L'. The lever also carries a contact-piece L at the end adjacent to
the tongue, and depending from the lever just above the tongue. The action
of the apparatus is as follows;
When the operator presses upon the button L, the lever L is depressed, and
the contact-piece La coming into contact with the tongue L2 completes the circuit
through one or more of the replacing coils of the indicator. If, however, at this
point or during this action a signal current passes round the coil L', the tongue L'
is turned away from the iron bar L³ towards the core of the coil L in the manner
already described with reference to the polarised movements shown in Figures 2, 3
and 4. The signal current thus breaks the circuit through the replacing coils
and prevents the replacing of the signals connected therewith. Upon cessation
of the signalling current through the coil L' the hook L' will serve to draw the
tongue away from the core of the coil up against the end of the iron bar L'.
Suitable terminals are provided for the circuits through the coil L' and through
the tongue and contact-piece LB respectively, and a spring L serves to return the
brass lever L to its normal position after it has been depressed thus lifting the
hook & pulling up the tongue. A flexible diaphragm L is preferably provided
as a watertight cover to the apparatus, the button La passing tightly through a
central hole in the diaphragm.
5
Figure 10 is a plan of a "compound armature," M being the timbers upon
which it is supported and M a series, in the example illustrated 4 in number, of
pole-plates or collectors for the magnetism from the track magnets. The four
collectors M thus form three bays in which three armature movements Ms may
be supported by "gap bridges" or divided bridges M. By this construction 5
the three arinature movements M³ are served by four instead of by six collectors
as would be needed if three simple armatures were employed.
In Figure 11 the armature is shown in cross section in position over a track

page_text: electro-magnet, the coil of which is shown at O, the core at 0', the pole-plates
at O, and the supports at 03. The whole is shown mounted on sleepers O, the
rails being indicated at 0. The electro-magnet shown is operating upon the
central hay of the three comprised in the compound armature.
In the side elevation shown in Figure 12 are more clearly seen the links or
yokes which connect the cores O with the pole-plates 0.
"
The various parts of the track electro-magnet are clearly shown in detail.
Like letters in Figures 10, 11, 12 and 13 refer to like parts.
In Figure 13 the timber support for the electro-magnets is omitted.
In Figures 14 and 15 the permanent magnets are shown at P and the timber
supports therefor at P1 and P. 1 is a zinc cover a portion of which covering
the left hand part of the structure as shown in the drawing having been removed.
P represents an armature in position over the magnets and the rails are shown
as in other views at 06.
In Figure 16 is shown an arrangement of apparatus comprising several
polarised" "movements" according to this invention arranged to constitute an
A.B.C. telegraphic apparatus.
The transmitting apparatus comprises a spring arm R having on its upper
surface a projection R and a handle 1. The projection R¹ engages, when down-
ward pressure on the handle R2 is released, with the notches R in the under
surface of a bar R. The forward end of the arm R carries a spring contact
piece R adapted to make contact with the piece Rª upon the base R'. The pro-
jection R locks the arm R against circular movement and to release the arm it
is necessary to press upon the handle R. The spring R is so arranged that it
makes contact with the piece Rs before the projection R¹ is freed from the
notches R*.
It is thus impossible to move the arm from one contact R to any other without
passing over and making contact with all the intermediate ones. Each contact R6
is connected with a coil S of the receiving instrument the cores of the coils S
serving to act upon the pivotted tongue S carried by the magnet S. The coils
act in substantially the same manner upon the magnet S and tongue S₁ as has
hereinbefore been described with reference to Figures 2, 3 and 4. The coils have
a common return circuit to the arm R, a battery S being inserted at any
convenient position.
With reference to the apparatus hereinbefore referred to as the "spots" these
constitute what may be termed an "action indicator" since they serve to indicate
whether either or both of the needles with which they are connected have acted.
The term replacing coil" has been employed to indicate the coil which serves
to return a pivotted tongue to its normal position after it has been displaced by
a signal current.
11
With reference to the energizing of the repeater magnet H we do not confine
ourselves to an automatic device for this purpose but may provide if desired a
push or switch by which an official on the train may energize the magnet with its
polarity in one sense or the other as desired or always in one sense only.
Further whereas we have referred to a "polarised relay or movement we wish
thereby to indicate a mechanism the operation of which is reversible that is to
say we have spoken of a polarised tongue but do not necessarily mean (as the
word polarised commonly would do) one of hard steel and permanently mag
netised or having magnetism induced in it by means of a permanent magnet but
one which may be thrown in one direction or the other in accordance with the
nanner in which current is led into the apparatus.
Also whereas we have described the combination of route indications to form
other route indications we may obviously without departing from the spirit of
this invention combine other signals or indications than route indications to form
signals or indications for any other purpose.
An important feature of the method described of re-invigorating the permanent
magnets is that it can
be done without disturbance of the magnets

page_text: that is to say without the necessity of either removing them entirely
from their supporting structure or even of partially removing them or indeed of
moving them at all. "It is not even necessary to remove the zinc covering although
in some cases this may be preferable.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed we declare that what we
claim is;
1. In railway signalling "repeating" the signal to the signal cabin through
a separate electric circuit on the road controlled by the signal receiving apparatus
on the train.
2. In railway signalling the combination with a signal receiving apparatus
carried on the train of a signal repeating electro-magnet also on the train the
circuit of which is automatically controlled by the receiving apparatus.
66
61
3. In a polarised mavement" or relay splitting the magnetic flux due
to a coil for the purpose described.
"
4. Apolarised" movement or relay comprising two electro-magnets and
a movable polarised tongue arranged and operating substantially as described.
5. In electric signalling apparatus the combination of a pillar such as K a
tongue movably attached thereto both of magnetic material one both or neither
of which is permanently magnetised two electro-magnets K and a base of
magnetic material all arranged and operating substantially as described.
"
6. In a polarised movement or relay having two or more movable
polarised tongues replacing all the tongues by means of one coil.
il
7. In a polarised" movement' or relay having two or mor movable
polarised tongues simultaneously replacing all the tongues by means of one coil.
8. Apolarised ' movement" or relay having two or more movable polarised
tongues and electro maguets by which they are operated and one replacing coil
all mounted upon the same base forming their magnetic yoke.
"
9. The "polarised "movement" substantially as described and illustrated in
Figure 2 or Figure 3 or Figure 4.
10. In a polarised "movement" of the kind described in Claim 3 or Claim 4
arranging the circuits so that the signalling current arts more strongly than the
replacing current for either or both purposes described.
11. In railway signalling apparatus having duplicated electric circuits the
employment in either or both circuits of an action indicator operated by the
signalling current.
12. The signalling device substantially as described and illustrated in Figure 16
of the accompanying drawings.
13. The complete "replacer push" substantially as described or illustrated
in Figures 7, 8 and 9 of the accompanying drawings.
14. In an
armature" the employment of three or more pole plates or collectors
to form two or more bays across which the magnetic flux operates the number of
collectors being one in excess of the number of bays.
15. Forming a route indication by the combination of two or more other route
indications.
16. In railway signalling the combination of one or more permanent magnets
and one or more electro magnets to form a signalling pair arranged in such a
manner that the train arrives first at the permanent magnets of a pair and receives
therefrom a danger signal to be subsequently reversed or not by the electro
magnets according as the latter are energised or not.
17. In apparatus of the kind described the employment of a "re-invigorating
magnet" substantially as described.
18. In railway signalling apparatus where permanent magnets are used in com-
bination with the track the employment of apparatus whereby the maguets are
re-invigorated without disturbing them.
"
19. A reinvigorating magnet" suspended by one or more springs from a
vehicle adapted to travel upon the rails.

page_text: 20. A "reinvigorating magnet" having its poles provided with brushes springs
or rollers substantially as and for the purpose described.
21. In railway signalling the combination with a permanent magnet and signal
receiving apparatus such as an armature" operated thereby of a coil surround-
ing the magnet and adapted to repeatedly reverse its polarity substantially as
described.
22. The arrangement and electric interconnection of signalling apparatus and
circuits therefor substantially as described and illustrated in Figure 1 of the
accompanying drawings.
23. The combination and arrangement of parts forming the indicator substan-
tially as described and illustrated in Figures 5 and 6 of the accompanying
drawings.
1000