IMPROVEMENTS IN RAILWAY SIGNALLING
Year: 1881

page_text: LETTERS PATENT to Edward Tyer, of Ashwin Street, Dalston, in the County
of Middlesex, for an Invention of "IMPROVEMENTS IN RAILWAY SIGNALLING.
LETTERS PATENT to Edward Tyer, of Ashwin Street, Dalston, in the County
of Middlesex, for an Invention of "IMPROVEMENTS IN RAILWAY SIGNALLING.
AND IN APPARATUS FOR EFFECTING THE SAME BY ELECTRICITY."
PROVISIONAL SPECIFICATION left by the said Edward Tyer at the Office of
the Commissioners of Patents on the 1st July 1881.
EDWARD TYER, of Ashwin Street, Dalston, in the County of Middlesex.
"IMPROVEMENTS IN RAILWAY SIGNALLING, AND IN APPARATUS FOR EFFECTING
THE SAME BY ELECTRICITY."
My Invention relates to signalling on railways by means of coloured electrical
lights, and to apparatus by which such signals are brought into action and taken
out of action. I mount on a suitable signal post two or more electrical lamps,
which may be of any known kind, preferably those in which the light is produced
by incandescence, as these do not require delicate regulating apparatus, and I
provide the said lamps with lenses of different colours, such as red and green.
Near the signal post or at the signal cabin I provide a battery, dynamo electric
machine, or other source of electricity. This battery is connected with the electrical
lamps on the post by conducting wires to two or more contact making and
breaking relays, worked as I will presently describe. Usually contact is broken,
so that there is no light from the lamps, and no expenditure of electricity. Contact
is made only from time to time for short periods during which the signal is
required, the two relays for this purpose being worked by the conjoint action of
the signalman at a neighbouring signal station and of a train passing along the
line. As an example of the mode of operation for an ordinary signal, I will assume
that there are two incandescent lamps on the signal post, one with a green lens and
the other with a red lens. The lever employed for working the ordinary signal, or
the handle for transmitting a telegraphic signal, when in the position corresponding
to "safety" makes an electrical connection, and transmits a current of electricity,
which, by acting on a polarised relay near the signal post, shifts its contact so as
to make a connection from the battery to the green lamp, but not to complete the
Povice 1071

page_text: circuit thereto. In like manner when the signal lever or handle is in the position
corresponding to "danger," it makes a connection which, transmitting a current of
electricity of an opposite polarity through the relay, causes the contact to shift, so
as to make a connection from the battery to the red lamp. As in neither case is
the circuit complete no light is produced, and no electricity is expended by the
battery. At some distance in advance of the signal post I provide a contact
apparatus of a kind which I will presently describe, so arranged that the deflection
of the rail caused by a passing train effects transmission of an electric current to
the second relay near the signal post, which completes the electrical connection to
either the green or the red lamp, as the case may be, and at the same time closes
a local circuit extending to a second contact apparatus fixed at a suitable point
beyond the signal lamp nearer the signal station or cabin. Thus, assuming that
the signal lever or handle is in the "safety" position, a train coming towards the
signal post in passing the contact point in advance of it starts the green light,
which remains visible until the train has passed the post; and, on the other hand,
if the signal lever be at " danger," the train as it comes towards the signal post
starts the red light. At some distance beyond the signal post I provide another
contact apparatus to be acted on by a passing train. This contact apparatus
normally makes contact and completes the local circuit of the second relay, but by
the passage of a train breaks contact therewith, and permits the second relay to
resume its normal position. When therefore the train has passed beyond the signal
post it breaks the contact for the second relay, and the lamp being thus disconnected
from the battery is extinguished. The arrangement may be modified as follows:-
A third contact apparatus may be provided near the signal post to be acted on by
the passing train, so as to complete connection for the red light. Thus a train
approaching a post may start the green light, shewing that it may safely proceed,
but on passing the post it extinguishes the green light and starts the red light,
which remains visible until the train shall have passed the farther contact apparatus.
A second train then coming towards the post will be directed by the red light to
stop until the train in front of it shall have passed the farther contact apparatus,
and so have extinguished the light. The arrangement of signal posts and contacts
may obviously be extended along a line of railway, so as to operate as an automatic
safety block system, every train as it approaches a post starting the signal light,
and not extinguishing it until it shall have passed a point sufficiently far beyond
to prevent the too near approach of a succeeding train. As in no case is a light
started except when it is required for the use of a train actually on the part of the
line to which the signal belongs, there is comparatively little expenditure of
electricity, and consequently signals operating as I have described may be worked
with great economy as compared with ordinary signal lights, which are kept
constantly burning at night. Moreover in cases where many signals are required,
as in a station yard, there is apt to be confusion as to the lines to which they
severally apply. By the systein which I have described the chance of confusion
may be greatly reduced, because only those lights will be simultaneously visible
that belong to portions of line actually occupied by trains. The contacts worked
by passage of a train may be of any known kind suitable for making or breaking
contact. A contact apparatus for this purpose, according to my present Invention,
is of the following kind:-1 clamp on to the rail flange or lower side of the rail
between two sleepers a bracket, which extends at right angles to the rail.
On
this bracket I fix a weathertight box or case, which contains a ball of wood or
other somewhat elastic material fixed at the end of a horizontal blade spring.
From the spring an elastic bent arm carrying a contact pin extends over the ball,
but not touching it, immediately under a second blade spring, which has also a con-
tact pin, but not touching it. The two-blade springs are insulated and are connected
to two portions of line wire; or one of them is insulated, and the other is in
connection with "earth.” When the ball is in repose electrical continuity is
interrupted, the contact pius being separated, but when the rail is deflected by a
passing train the ball is caused to vibrate or jump up, pressing the two springs

page_text: together, and so making contact. A similar arrangement of contact apparatus
serves to break contact, the two springs being in this case arranged so as to be in
contact with each other while the ball is in repose, but to be separated by the
upward motion of the ball. Although I have above described the contact apparatus
as being worked by passage of a train for the purpose of starting and extinguishing
electric lights operating as signals, they may obviously be employed in connection
with signals of other kinds worked or governed by electricity. They may also be
employed in combination with polarised or other relays to control the working of
the telegraphic block signalling instruments. When, for example, a train enters a
section of the line, a contact apparatus acted on by it may cause the transmission
of a telegraphic signal shewing that the section is occupied; and this condition
will be maintained until the train by its passage over another contact apparatus
on leaving the section restores the electrical connections and the instruments to
the state in which they can properly be used when the section is clear.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Edward Tyer in the Great Seal Patent Office on the 28th December
1881.
EDWARD TYER, of Ashwin Street, Dalston, in the County of Middlesex.
"IMPROVEMENTS IN RAILWAY SIGNALLING, AND IN APPARATUS FOR EFFECTING
THE SAME BY ELECTRICITY."
My Invention relates to signalling on railways by means of coloured electrical
lights, and to apparatus by which such signals are brought into action and taken
out of action. I mount on a suitable signal post two or more electrical lamps
which may be of any known kind, preferably those in which the light is produced
by incandescence as these do not require delicate regulating apparatus; and I
provide the said lamps with lenses of different colours, such as red and green.
Near the signal post or at the signal cabin I provide a battery, dynamo electric
machine, or other source of electricity. This battery is connected with the
electrical lamps on the post by conducting wires to two or more contact making
and breaking relays worked as I will presently describe. Usually contact is
broken, so that there is no light from the lamps and no expenditure of electricity.
Contact is made only from time to time for short periods during which the signal
is required, the two relays for this purpose being worked by the conjoint action
of the signalman at a neighbouring signal station and of a train passing along the
line. As an example of the mode of operation for an ordinary signal, I will
assume that there are two incandescent lamps on the signal post, one with a green
lens, and the other with a red lens. The lever employed for working the ordinary
signal or the handle for transmitting a telegraphic signal when in the position
corresponding to "safety" makes an electrical connection and transmits a current
of electricity which by acting on a polarized relay near the signal post shifts its
contact so as to make a connection from the battery to the green lamp, but not to
complete the circuit thereto. In like manner. when the signal lever or handle
is in the position corresponding to "danger" it makes a connection, which
transmitting a current of electricity of an opposite polarity through the relay
causes the contact to shift so as to make a connection from the battery to the red
Jamp. As in neither case is the circuit complete no light is produced, and no
electricity is expended by the battery. At some distance in advance of the signal.
post I provide a contact apparatus of a kind which I will presently describe, so
arranged that the deflection of the rail caused by a passing train effects trans-
mission of an electric current to the second relay near the signal post which
completes the electrical connection to either the green or the red lamp, as the case
may be, and at the same time closes a local circuit extending to a second contact
apparatus fixed at a suitable point beyond the signal lamp nearer the signal station or
cabin. Thus, assuming that the signal lever or handle is in the "safety" position, a
train coming towards the signal post in passing the contact point in advance of it
starts the green light, which remains visible until the train has passed the post. And
on the other hand, if the signal lever be at "danger," the train as it come towards
the signal post starts the red light. At some distance beyond the signal post I provide
another contact apparatus to be acted on by a passing train. This contact apparatus
normally makes contact and completes the local circuit of the second relay, but by
the passage of a train breaks contact there with and permits the second relay to
resume its normal position. When therefore the train has passed beyond the signal
post it breaks the contact for the second relay, and the lamp being thus discon-
nected from the battery is extinguished. The arrangement may be modified as
follows: A third contact apparatus may be provided near the signal post to be

page_text: acted on by the passing train, so as to complete connection for the red light. Thus
a train approaching the post may start the green light shewing that it may safely
proceed, but on passing the post it extinguishes the green light and starts the red
light, which remains visible until the train shall have passed the farther contact
apparatus. A second train then coming towards the post will be directed by the
red light to stop until the train in front of it shall have passed the farther contact
apparatus, and so have extinguished the light. The arrangement of signal posts
and contacts may obviously be extended along a line of railway so as to operate as
an automatic safety block system, every train as it approaches a post starting the
signal light, and not extinguishing it until it shall have passed a point sufficiently
far beyond to prevent the two near approach of a succeeding train. As in no case is a
light started except when it is required for the use of a train actually on the part
of the line to which the signal belongs, there is comparatively little expenditure of
electricity, and consequently signals operating as I have described may be worked
with great economy as compared with ordinary signal lights which are kept
constantly burning at night. Moreover in cases where many signals are required,
as in a station yard, there is apt to be confusion as to the lines to which they
severally apply. By the system which I have described the chance of confusion
may be greatly reduced, because only those lights will be simultaneously visible
that belong to portions of line actually occupied by trains. The contacts worked
by passage of a train may be of any known kind suitable for making or breaking
contact. A contact apparatus for this purpose according to my present Invention
is of the following kind:-I clamp on to the. rail flange or lower side of the rail
between two sleepers a bracket, which extends at right angles to the rail. On this
bracket I fix a weathertight box or case, which contains a ball of wood or other
somewhat elastic material fixed at the end of a horizontal blade spring. From the
spring an elastic bent arm carrying a contact pin extends over the ball but not
touching it, immediately under a second blade spring which has also a contact pin,
but not touching it. The two blade springs are insulated and are connected to
two portions of line wire, or one of them is insulated and the other is in connection
with "earth." When the ball is in repose electrical continuity is interrupted, the
contact pins being separated, but when the rail is deflected by a passing train the
ball is caused to vibrate or jump up, pressing the two springs together and so
making contact. A similar arrangement of contact apparatus serves to break
contact, the two springs being in this case arranged so as to be in contact with
each other while the ball is in repose, but to be separated by the upward motion of
the ball. Although I have above described the contact apparatus as being worked.
by passage of a train for the purpose of starting and extinguishing electric lights
operating as signals, they may obviously be employed in connection with signals of
other kinds worked or governed by electricity. They may also be employed in
combination with polarized or other relays, to control the working of the telegraphic
block signalling instruments. When, for example, a train enters a section of the
line, a contact apparatus acted on by it may cause the transmission of a telegraphic
signal shewing that the section is occupied. And this condition will be maintained
until the train, by its passage over another contact apparatus, on leaving the section
restores the electrical connections and the instruments to the state in which they
can properly be used when the section is clear.
In cases where audible signals are required in lieu of or in addition to the
visible signals, an electric gong or bell may be introduced into the circuit, and in
order to distinguish such audible signals gongs or bells of different tones or periods
may be used, the gong or bell giving one sound corresponding with the red light,
and the gong or bell giving another sound corresponding with the green light. I
will now describe the arrangement of the electrical connections, and the construction
of the apparatus which I employ to carry my Invention into practical operation,
referring to the accompanying diagrams and Figures.
Fig. 1 is a diagram shewing the arrangement on a section of railway line for a
block signal worked by passing trains.. The signal S (which may be, as stated

page_text: above, a lamp, or a gong, or both combined) situated at the beginning of the
section, and a battery B near it are connected through a relay apparatus R by a
line wire L, L¹, with two points of the line A and C at which are situated contact
apparatus. The apparatus A is a little in advance of the signal S, and is of such
a kind that the line L is usually kept by it separate from earth E, but that by
the passage of a train at A contact is made from L to E. The apparatus at C is
placed at the further end of the section, or at least at a sufficient distance beyond
the signal S that a train directed to stop by the signal at S shall have room to do
so before it can overtake a train at C. The contact apparatus at C is of such a kind
that it usually connects the line L¹ with earth E, but the contact is broken by the
passage of a train at C. Thus when a train proceeding in the direction of the
arrow passes the point A it closes a circuit, by which the battery B acting through
to sound,
the relay apparatus R connects itself with the signal S causing the
gong
or the red light to appear, or both to act together as a danger" signal, which
continues until the train reaches C. In passing C the train breaks contact and
the relay apparatus R returns to its former condition, causing the signal to cease.
Thus until the train has passed C the signal continues to operate, warning a
succeeding train against entering the section of line already occupied. Obviously
by dividing the line into sections of suitable length, cach provided with signal
apparatus as described, every train in entering a section will start the signal.
covering that section, and the signal will be maintained against a succeeding train
until the former train shall have left the section.
"
In such
In cases where a section is commanded by a signal box for the contact breaking
apparatus C acted on by a passing train may be substituted a contact apparatus
worked by the signalman, who can break contact and so stop the action of the
signal when the train has passed his box, or who can maintain the signal longer in
action if necessary to prevent another train from entering the section.
cases however a modified arrangement of the apparatus may be adopted, as
illustrated diagrammatically at Fig. 2. In this arrangement the visible signal S
is duplicated so as to present either a red light S or a green or white light S¹, and
the gong may also be duplicated so as to give two distinct sounds. Between the
relay apparatus R and the signals is introduced a polarised relay P connected by
a wire L with a suitable key K in the signal box, by which the signalman can
transmit either a positive or a negative current from his ordinary signalling
battery B². When he transmits the one current he causes the polarised relay P
to move so as to bring the one signal S into connection with the relay R; when
he transmits the opposite current the other signal S₁ is put in connection with R.
The make and break contact apparatus A and C are as already described except
that A should be situated at a greater distance in advance of the signal. When
the line is clear the signalman by his key K transmits such a current through L²
to P as will connect the "safety" signal S' to R. A train then passing A will
cause that signal to be displayed. If however the signalman desires to block the
line, lie by his key K. sends a current to P, which will put the "danger" signal S
in connection with R, and in that case a train in passing A will cause that signal
to be displayed, and will consequently stop before reaching the signal, and remain
arrested till the signalman changes the signal to "safety."
"
Obviously there might be many other arrangements to suit different circum-
stances of lines and of the traffic on them, the parts of the apparatus being disposed
according to the exigencies of each case. I will now describe these parts
separately.
Fig. 3 is a transverse section shewing the apparatus at A arranged so that the
passage of a train makes contact of the line wire L to earth. On the lower part
of the rail X between two sleepers is clamped a bracket D carrying on it a weather-
light box E. Within this box a ball F of wood or other somewhat elastic material
is attached to a blade spring f having another spring f1 projecting from it just above
the ball. An insulated spring G connected to the line wire L extends just over
but clear from the spring f¹, so that while the apparatus is in repose there is no

page_text: contact of the springs G and f¹. When however a train passes over this part of
the rail X, the oscillation causes the ball F to jump upwards, pressing the springs f¹
and G into contact, and thus for the time putting the line wire L in connection
with earth.
The apparatus at C for causing the passage of a train to break contact differs
froin that at A only, as shewn in Fig. 4, the bent spring f' being in this case
extended and having its end f bent over the end of the spring G so as to be in
contact with it. The oscillation caused by a passing train causes f2 to rise away
from G, thus breaking contact.
Fig. 5 is a diagram shewing the general arrangement of the connections for the
polarised relay indicated at P in Fig. 2, the polarised relay combined with the
other relay R being shewn to an enlarged scale in front view at Fig. 5ª, and in
plan at Fig. 5b; His a thin cylindrical shell armature of soft iron cut into two
semicylinders. It is mounted on an axis between the poles N, S, of a permanent
magnet which polarises it, and also between the poles M, M', of an electro magnet,
the coils of which are in the circuit of the signalman's line L² to earth E. From
the axis of the armature H projects an arm h which can make contact with either
of two springs S, S', the one leading to the "danger" lamp or gong, and the
other to the "safety" lamp or gong. The axis of H is also connected by a
wire L³ to the relay R. When the signalman transmits through L³ a current of
the one sign, say positive, the armature H takes such a position as to make contact
with the spring S, so that when a current is transmitted from R through L³ the
"danger" signal is exhibited. When the signalman transmits an opposite, say
negative current, through L2, the armature H turns partly round, so as to bring the
arm h to the dotted position h', making contact with S¹, and now when a current
passes from R through L³ the "safety" signal is exhibited. It is to be understood
that when the apparatus is arranged as indicated in Fig. 1 for automatic block
signalling, the polarised relay shewn in Fig. 5 is unecessary.
Fig. 6 shews diagrammatically the electrical connections for the relay apparatus R,
which apparatus is shewn to an enlarged scale in Figs. 50 and 5b in combination
with the polarised relay P. The local battery B is that which works the signal S.
A portion of this battery, or it may be a separate small battery B', works the relay.
The main battery B is connected by a wire L³ to the signal S when only one signal
is employed, as in the arrangement illustrated by Fig. 1; or when two distinct
signals are used, as illustrated by Fig. 2, B is connected by L³ to the axis of the
polarised armature H, as shewn in Fig. 5. The spring armature T of an electro.
magnet Qis connected to the line wire L', and when it is attracted it makes two
contacts, connecting L¹ to S, and t connecting L¹ to Q. When a train passing A
makes contact, then the battery B¹ having its circuit closed excites the magnet Q,
causing its armature T to be attracted, and thus, by making the contacts t and t¹,
to close the circuit of the battery B through S, L¹, and C, and of B¹ through Q, L',
and C. When the train passing C breaks contact, the contact at A having been
previously broken, the signal S ceases, and also the attractive power of Q, and the
armature T being withdrawn by its spring breaks the contacts t, t, the apparatus
remaining then in a state ready for a subsequent action of like kind.
When in addition to a luminous signal a bell or gong is also employed for
audible signalling, I work it by a battery separate from that which works the
light; and in order that the audible apparatus may be brought into action when
the light is brought into action, I arrange the spring armature T (Fig. 6) to make
when it is attracted an additional contact besides those indicated at t and t¹. In
like manner when two bells or gongs are used to correspond with the red and
green lights, I arrange the segment h of the polarised armature H (Fig. 5) to make
contact with either of another pair of springs besides those indicated at S, S¹.
By these contacts the bell or gong apparatus is brought into action at the same
time as the corresponding light. The self intermitting gong apparatus may be
arranged as shewn diagrammatically at Fig. 7. It consists of an electromagnet M,
with its armature V suspended by a spring v, and carrying at its end a hammer H

page_text: to strike the gong G. At the back of the armature which is in the circuit of the
electro magnet M is a contact stud I, which closes the circuit when the armature
is withdrawn, by its spring; the magnet being in that case excited attracts the
armature, causing the hammer H to strike the gong G. The advance of the
armature breaking contact with I the attraction ceases, the armature retreats, again
makes contact, is again attracted, and so on repeatedly until the electric current
ceases.
The two signal lights are arranged side by side in a casing behind coloured
lenses, as shewn in Fig. 8, which represents a front view of the casing, the
front cover being partly removed on the one side to shew the interior; Fig.
is a transverse section. A is one of the incandescent electric lamps, with a
reflector B behind it and the coloured lens C in front of it. Both lamps are on a
metal plate D, connected by a wire from the contact screw E to the one pole of the
local battery, one terminal of each lamp being connected to the plate D. The
other terminal F of each lamp is connected by the screw G to a wire leading
to one of the contact springs S, S', of the polarised relay P. The telegraphic block
signalling instrument which the signalman employs to work the polarised relay
is similar to the instrument generally in use for block signalling, with certain
additions and modifications to render it applicable in the manner described above.
Fig. 10 is a front view; Fig. 11, an internal view of the back; Fig. 12, an internal
view of the front looking from within; Fig. 13 is a vertical section; Figs. 14, 15,
and 16 are plans respectively on the lines X, X, Y, Y, and Z, Z, of Fig. 13. A is
the signalling plunger carrying on its inner end the commutator disc B. The
plunger slides in a boss C, which can be turned partly round to either of two
positions, and carries a screen D, which presents through a hole in the casing the
word "danger "when the boss C is turned to the one position and the word
"safety" when it is turned to another position. By pushing in the plunger A the
commutator disc B is pressed against 4 springs E', E², E³, E, and metal plates on
the face of the disc connect these electrically in pairs according to the position into
which the boss C is turned, E' being connected to the - pole of the signalling
battery, E3 to its + pole, E to the line leading to the polarised relay (R, Fig. 5),
and E through the coils of a polarised relay F within the instrument; in one
position of the boss C, say, that in which the screen D shews "danger," the pushing
in of the plunger connects the springs E so that a + current is sent to the
polarised relays, causing the relay at the signal post to establish electrical connection
for the red light, and the relay F in the instrument to shew by a repeating signal
screen G through an aperture in the casing a red colour. If, on the other hand,
the plunger A be pushed in when the boss C is turned, so that D shews "safety,"
then the connections of the springs E are so made that the relays receive
a-
-
current, the connections at the signal post being thus established for the green
light, and the repeating screen G being made to shew green. I provide also a
needle K within a coil which is in circuit with the line of the local battery that is
started into action on the signals by the passage of a train over the contact maker
and thrown out of action by its passage over the contact breaker C. An index L
on the axis of K is thus made to point in the latter case to the marks
"train passed," "light out," and in the former case to "train approaching,"
light in."
"
Having thus described the nature of my Invention, and in what manner the same
is to be performed, I claim,-
First. Signalling on railways by means of an electric lamp which is brought
into connection with a local source of electricity by the passage of a train making
contact at one part of the line, and is kept in connection therewith till contact is
broken by the passage of the train over another part of the line, substantially as
herein described.
Second. Determining the exhibition of the one or the other of the two coloured
signalling lights by means of a polarised relay, which is caused by a current
transmitted by the signalman to make connection from the local battery to the one

page_text: or to the other light, according as a positive or negative current is transmitted,
substantially as herein described.
Third. For operating in the manner referred to in the preceding claim, the use of
combined relay apparatus, constructed and arranged substantially as herein
described with reference to Figs. 5, 5ª, and 5b.
Fourth. The construction of modified block signalling instrument, substantially
as herein described with reference to Figs. 10 to 16 inclusive.
In witness whereof, I, the said Edward Tyer, have hereunto set my hand
and seal, this Fourteenth day of December, in the year of our Lord One
thousand eight hundred and eighty one.
EDW. TYER. (L.S.)