AN IMPROVED MODE OF SIGNALLING ON RAILWAYS BY ELECTRICITY AND IN THE APPARATUS TO BE USED THEREFOR.
Year: 1874

page_text: LETTERS PATENT to George Whyte, of Northview, Elgin, North
Britain, Doctor of Medicine, for the Invention of "AN IMPROVED
MODE OF SIGNALLING ON RAILWAYS BY ELECTRICITY AND IN THE APPARATUS
TO BE USED THEREFOR.'
"
Sealed the 12th June 1874, and dated the 21st April 1874.

page_text: engine or tender or some vehicle on the train, and the other portion of
the said apparatus is to be applied to the road between or so near to the
rails of the permanent way as to be conveniently acted on by the portion
of the apparatus on the train.
The portion of the apparatus which I attach to the train, and which I
call the train apparatus, consists of a series of metallic contacts. I have
found in practice that three of these contacts is a convenient number,
and which for convenience of description I will distinguish by the
numbers 1, 2, and 3. Of these contacts numbers 1 and 2 are metallically
connected, and numbers 1 and 3 are also metallically connected, having
an electric bell in circuit; numbers 2 and 3 are metallically connected,
having a battery and bell in circuit. To the train apparatus is attached
at some convenient part a stud or wheel for the purpose of depressing
a lever on the road apparatus, which I will now proceed to describe.
Along the line and at suitable intervals apart, and either between the
rails or at some convenient position in the permanent way so as to be
acted on by the train apparatus, I place a series of insulated metallic
plates of sufficient length to be efficiently acted on by the contacts on
the train apparatus as the train passes along the line. Beneath the pair
of these metallic plates which correspond to the contact numbers 2 and 3
on the train apparatus, I place an electro-magnet, which the train in
passing and pressing down a small lever by the action of the stud or
wheel attached to the train apparatus connects with a battery at the
station. This small lever is attached to, and when acted on by the train
apparatus presses up a small metallic bar, which unites the metallic
plates and at the same time presses up the armature or keeper of the
electro-magnet, both of which are held in that position until the train
arrives at the next road apparatus, when the wheels of the train break
the circuit in connection with the electro-magnet, thus letting fall the
armature or keeper of the magnet and the small metallic bar, and so
disuniting the plates. As long as the metallic plates of the road.
apparatus remain united by the metallic bar any following train passing
over them has the bell on its train apparatus rung by its contacts
numbers 2 and 3 touching the metallic plates and completing the
circuit in connection with the battery and bell in the same, thus
warning the driver or guard of such following train that the preceding
train has not yet passed the next succeeding series of plates.

page_text: When it is desired that a signal should be given at a station two
insulated metallic plates to correspond with contacts numbers 1 and 2 are
placed in the roadway, which metallic plates are connected with a battery
and bell at the station, so that as the train passes over them the circuit
is completed by the contacts numbers 1 and 2 of the train apparatus,
which thereupon rings the bell at the station.
When it is desired that the bell should be rung on the train from a
station insulated metallic plates to correspond with contact numbers 1
and 3 are placed in the roadway. These metallic plates are connected
with a battery at the station, the circuit of which is completed by
contacts numbers 1 and 3 as the train passes over the metallic plates,
and thereby causes the bell in the circuit of the contacts numbers 1 and 3
to ring. This means of signalling to the train may be put in or out of
use by means of a switch at the station.
The whole of the road' apparatus may be worked either by a powerful
battery at the station, or a less powerful battery may be used at the
station supplemented by a small battery at each electro-magnet.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said George Whyte in the Great Seal Patent Office on
the 21st October 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
WHYTE, of Northview, Elgin, North Britain, Doctor of Medicine, send
greeting.
·
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-first day of April, in the year of
our Lord One thousand eight hundred and seventy-four, in the thirty-
seventh year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said George Whyte, Her special license
that I, the said George Whyte, my executors, administrators, and
assigns, or such others as I, the said George Whyte, my executors,
administrators, and assigns, should at any time agree with, and no
others, from time to time and at all times thereafter during the term

page_text: therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "AN IMPROVED MODE
OF SIGNALLING ON RAILWAYS BY ELECTRICITY AND THE APPARATUS TO BE USED
THEREFOR," upon the condition (amongst others) that I, the said George
Whyte, my executors or administrators, by an instrument in writing
under my, or their, or one of their hands and seals, should particularly
describe and ascertain the nature of the said Invention, and in what
manner the same was to be performed, and cause the same to be filed
in the Great Seal Patent Office within six calendar months next and 1
immediately after the date of the said Letters Patent.
NOW KNOW YE, that the said George Whyte, do hereby declare
the nature of the said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by
the following statement thereof, that is to say :-
This Invention relates to the establisment of an absolute block system
of railway signalling by means of electricity along the entire length of
railway, and also to a system of signalling from and to a train to and from
any station on a line of railway.
The apparatus which I use for the above purposes is an electro-magnetic
apparatus, consisting of separate portions or parts, one portion or part
of which is to be applied to and placed on the engine or tender, guard
van, or some vehicle on the train, and one other portion or part of the
said apparatus is to be applied to the roadway, between or so near to the
rails of the permanent way as to act on or be acted on by the portion of
the apparatus on the train. Another portion or part is a contact
breaker, which is also applied on or near to the road to be acted on by
the passing train, and so break the circuit closed at the previous
apparatus.
The portion of the apparatus which I attach to the train (and which
I call the "train apparatus") consists of a series of metallic contacts
with signal apparatus attached thereto.
The portion of the apparatus which is applied to the road (and which
I call the "road apparatus") consists of two parts, one a contact making
and the other a contact breaking apparatus, which are placed along the

page_text: line and at suitable intervals apart, and either between the rails, or at
some convenient position on, over, or by the side of the permanent way,
so as that the respective portions of the said road apparatus may act on
or be acted on by the corresponding portion of the train apparatus, and
which road apparatus, when so acted on by the train apparatus, shall
effect either a block system of signalling, or enable the train to signal
its approach to or departure from a station, or enable the person in
charge of a station or signal box to signal to the train, cither in leaving
a station for the purpose of recalling it, or in approaching a station to
stop the train.
Having now described the nature of the said Invention, I will proceed
to describe more particularly the mode and apparatus in and by which
my said Invention may be performed or carried into effect, and for this
purpose will make use of the Drawings hereunto annexed, in each of the
Figures of which the same letters or figures of reference indicate similar
parts of the apparatus.
Figure 1 represents in clevation the train apparatus as applied to the
engine, or it may be to a tender, a guard's van, or other vehicle of a
train.
Figure 2 a side section, and Figure 3 a perspective drawing of one
form of the contact making portion of the road apparatus for the block
system of signalling.
Figure 4 a side section, and Figure 5 a plan of another form of the
contact making portion of the road apparatus for the block system of
signalling.
Figure 6 a plan of the contact breaking portion of the road apparatus
as applied by the side of the rail, or which may be placed within the
water-tight and dust-tight case which contain the electro-magnets M, M,
and other parts connected therewith for the said block system of sig-
nalling; and Figure 7 an enlarged plan view of part of the said contact
breaking. portion of the road apparatus shewn on Figure 6.
Figure 8 a plan of the apparatus for maintaining or continuing tho
ringing of the electro-magnetic signal bell; and Figure 9 a plan of the
several apparatus, both for the block system of signalling, and also for
5 signalling between the train and a station as applied to a single pair of:

page_text: rails of a double line of railway. For the return journey on a single
line another electro-magnet, similar to M, M, and its connctions must be
placed at the other side, and connected by insulated wires to the other
ends of each pair of the insulated line metallic plates 3ª and 4*,
lever and apparatus, as shewn in Figures 2 and 3, and 4 and 5.
TRAIN APPARATUS.
with
The train apparatus, as shewn by Figure 1, consists of a series of
metallic contacts, marked respectively 1, 2, 3, and 4, attached to somo
portion of the engine or tender, guard's van, or some other vehicle of the
train. In my Provisional Specification I stated that I found in practice
that three of these contacts was a convenient number, but I have since
the date of my said Provisional Specification found that four is a more
convenient number. I may however state that the number of the
contacts may be increased, but they must correspond in number and
position with the contact plates of the road apparatus, as will be evident
when my entire apparatus and its application is clearly understood.
These contacts are constructed and arranged in such a manner as that
they shall come down so near to the roadway as to come in contact with
corresponding metallic contact plates of apparatus fixed on the said
roadway. Each of the ends of these contacts nearest the road is
furnished with either a metallic brush, or a piece of metal hinged, and
with springs, so as to allow a backward and forward movement, so as
that when the train passes they shall make contact with the plates of
the road apparatus, without offering so much resistance as to injure
either themselves or the said plates. Of these contacts 1 and 2 are
metallically connected; 2 and 4 are also metallically connected, having
an electric bell z in the circuit; and 3 and 4 are also metallically con-
nected, having a battery y and bell in the circuit. The contacts
marked 3 and 4 are placed one on each side of the centre line of the
engine or vehicle, 1 and 2 being placed, as represented in Figure 1,
between contact 3 and the wheels of the engine or vehicle. Between
contact 4 and the wheels on the other side is placed a stud w, terminated
by a small wheel t for the purpose of depressing the lever 7 (Figures 2,
3, 4, and 5,) of the road apparatus. The stud to should be so arranged
that when the train goes backward the lever may not be depressed.
This may be done either by having the stud hinged, or else by means of
an arrangement to have it removed out of the way.
J

page_text: For convenience of description I shall describe first the apparatus to
bo used for the block system of signalling, and afterwards the manner
and apparatus in and by which the train signals at a station its
approach to or departure from that station, and also the manner and
apparatus in and by which any person in charge of a station or signal
box may signal to a train approaching or leaving that station.
Along the line at intervals which may be found convenient, according
to the character of the line and amount of traffic thereon, for example,
at intervals of one mile, as shewn at 3, 4, Figure 9, are placed apparatus
such as that represented by Figures 2 and 3, or by Figures 4 and 5. This
apparatus consists of two insulated metallic contact plates 3" and 4",
corresponding to and to be acted on by the metallic contacts 3 and 4 of the
train apparatus as the train passes over the road apparatus. These metallic
contact plates should be from two to four inches broad, about half an inch
thick, and from five to ten feet long, but these dimensions may be varied
without departing from the principle of my Invention. The metallic con-
tact plates are supported on the frame A, A, and they should be bevelled at
the ends, as represented in Figures 2, 3, and 4. Attached to the end of
cach plate is an insulated metallic wire c, c, d, d. By the side of the
metallic contact plate 4, and at the front end thereof, is placed an
electro-magnet M, Figures 2, 3, 4, 5, and 9, the poles of which F, F, are
turned downwards, the armature or keeper of which K, K, Figures 2
and 3, is supported on a three-cornered block or bell crank J, which is
supported by and turns on a pivot j (Figure 2). The armature or
keeper K, K, rests upon two spiral or other springs S (Figure 2), onc
placed at each end thereof. The object of these springs being to
prevent any shock to the apparatus when the lever L is depressed by
the passing train, and the armature or keeper thereby thrown against
the poles of the electro-magnet, across the centre of the armature or
keeper K, K, and at right angles to it is firmly fixed a small bar G,
having at each end a small metallic plate or pillar a and d. To the
pillar dis attached the insulated metallic wire proceeding from the
metallic contact plate 3ª, and to the pillar a is attached one end of the
insulated wire forming the coil of the electro-magnet at a². The electric
current from the battery enters at b, b, b, and passing through the small

page_text: The
spiral or other spring 6' to the small metal plate 6s, the circuit of the
magnet being closed at a, b, the instant the keeper K, K, begins to
approach the poles F, F, excites the electro-magnet' M.. The electric
current passes out by the wire, Figure 3, the return wire.
insulated wire c, c, from the metallic contact plate 4ª proceeds to a small
metallic disc c¹ supported on a spiral or other spring, so that when the
armature or keeper K, K, is raised towards the poles F, F, of the electro-
magnet, c¹ comes in contact with the metallic pillars d, and then the
metallic contact plates 3 and 4* become metallically united through the
insulated wire c, c, d, d, firm contact being effected by the spring. In
front of the electro-magnet M is placed a lever L, supported by its
fulcrum e on an upright E. One end of the lever is attached by a cord
or chain passing round the pulley H to the three cornered block or bell
crank J, and the other end is so bent as to be conveniently pressed upon
by the wheel at the end of the stud wo on the train apparatus.
At N, N, Figure 9, by the side of the rail, is placed the contact
breaking apparatus, shewn at Figure 6. This contact breaker consists
of a lever N placed by the side of the rail, and kept there by a blade or
other spring "n." This lever is so formed and placed on the road near
to the rail that the flange of some wheel of the train shall act upon it
and press it from the rail, and in so doing the other end of the said lever
acts upon a metallic piston P (see the enlarged plan, Figure 7), pushing
it back until the larger portion of the piston P is pressed so far back as
that the metallic springs Q, Q, to which the battery wires W¹, W¹, are
attached, fall upon the non-conducting rests R, R, and the metallic ends
of the said springs Q, Q, fall clear of the larger portion of the piston,
and thereby the contact becomes broken. The piston P is kept out by
the spiral spring shewn on Figure 7, and the contact between the
wires W¹, W¹, is maintained through the larger portion of the piston P
by the metallic ends Q', Q', pressing on the larger portion of the piston.
The contact breaking apparatus, Figure 7, as an alternative plan may
be placed within the case in which are the clectro-magnets with their
connections, and the pulley which is attached to the bell crank (J) may
be made to act on the piston P, and so break contact.
The operation of the block signalling apparatus is as follows:-When a
a train passes along the line in the direction of the arrow, Fig. 9, the

page_text: wheelt at the end of the stud W depresses the lever L, and thus raises
the keeper K, K, towards the poles F, F, of the clectro-magnet. The
instant however that the keeper K, K, begins to rise, and before it has
touched the poles F, F, of the electro-magnet, the circuit through the
electro-magnet at a, b, is closed, whereby the electro-magnet becomes
excited, and the keeper is in consequence retained against the poles until-
the circuit is broken, and as at the same time c and d come in contact
by the elevation of the keeper, the metallic contact plates 3 and 4* are
maintained metallically united through the insulated wires c, c, and d, d,
so long as the keeper is against the poles of the magnet.
If before the contact is broken by the train passing on to the next
apparatus and acting on the contact breaker at N a second train comes
up to apparatus No. 1, the contacts 3 and 4 on the second train press
upon the metallic contact plates 3" and 4" of the said apparatus No. 1,
and as these are metallically united, as above described, and the
contacts 3 and 4 of the train apparatus being also metallically united,
having an electric bell and battery in circuit, the electric bell necessarily
rings directly the contacts 3 and 4 come in contact with the metallio
contact plates 3" and 4".
The apparatus to maintain the ringing of the electric bell is shewn at
Fig. 8, and is herein-after described. If however the first train has
arrived at apparatus No. 2, the electric circuit is broken either by the
flange of the wheel acting on the lever of the contact breaking apparatus
at N, as has been explained, or by the pulley of the lever L acting upon
the piston P when the lever L is depressed. The instant the circuit is
thus broken the armature or keeper K, K, of the apparatus No. 1 falls,
the circuit at a, b, is also broken, and the two insulated metallic contact
plates 3 and 4 are disunited by the separation of the two small plates c
and d, so that if a train now passes the apparatus No. 1 the electric bell
on it will not ring, inasmuch as the contacts 3 and 4 on it will not now
complete an electric circuit, the circuit being broken at c and d. The
first train at the same moment that it breaks the circuit through the
electro-magnet of apparatus No. 1 closes the circuit of apparatus No. 2
by the wheelt at the end of the stud W depressing the lever L of
apparatus No. 2, and so at each apparatus all along the line of railway,
the entire line being thus divided into sections, the train as it enters
each section thus .blocking that section, so that no following train can

page_text: enter that section until the first train has left it and entered the next
succeeding section without having a bell rung or other signal given on
such following train, as when the circuit is closed by the passing train
an electric current is passing along the wires. A semaphore may be
kept up at any place between the blocks by means of an electro-magnet
placed in the circuit, the semaphore being raised by the wheel t acting
upon a lever like L, having a pulley attached to the semaphore, the
semaphore falling where the circuit is broken at the block in front. A
semaphore may also be attached to the keeper K, so as to be raised with
it and kept up so long as the said keeper is held by the electro-magnet,
thereby providing a visible signal on the line, as well as an audible one
on the train..
Figures 4 and 5 shew a somewhat different arrangement of the contact
making portion of the road apparatus for the block system of signalling.
In this arrangement the electro-magnet M is placed vertically instead of
horizontally, as in Figs. 2 and 3, the three cornered piece or bell crank J
is dispensed with. The end of the lever L is attached directly to the
bar G, on which the metallic plates or pillars a and d are mounted, and
this bar G is hinged at g. The spiral spring S is placed at the point
where the lever Lis attached to the bar G. All other points in which
the modification differs from that shewn in Figs. 2 and 3 will be readily
understood by an inspection of Figs. 4 and 5 of the Drawings. .
The electro-magnets, with all their connections of the road apparatus,
(with the exception of the contact plates 3ª and. 4) and also the contact
breaker should be placed in dust-tight and water-tight cases, and the
hole through which the wires, and also the connection between the
lever L and the three corner piece or bell crank in Figs. 2 and 3, and
the connection between the lever L and the bar G in Figs. 4 and 5
should be protected in such a way as to prevent dust or wet entering the
case. This may be effected by arranging a piston to work through a
packing in the hole.
Although in my Drawings I have represented the road apparatus as
placed on the roadway, the parts may be separated, and the electro-
magnet M, M, with its connections may be removed to any convenient
place near to the roadway. The metallic contact plates and lever L
may also be placed in some other position than on the roadway, but in

page_text: all cases the train apparatus must be placed on the train in such a
position as that its parts may correspond with the position of the said
contact plates and lever L.
I will now describe the apparatus by means of which a train may
signal its approach to a station. At a distance, say a mile, from a station
there are placed on the roadway two insulated metallic contact plates 1*
and 2ª (see Fig. 9) to correspond in position with the metallic contacts
1 and 2 on the train. These contact plates 1° and 2ª are connected by
insulated wires to a battery in the signal box at the station (see Fig. 9),
having an electric bell (marked "bell" in Fig. 9) in circuit. As tho
train passes over these contact plates 1ª and 2", the contacts 1 and 2 on
the train (which are themselves metallically united) make contact and
the electric bell at the station rings, the ringing being maintained by the
apparatus shewn at Fig. 8 and herein-after described.
I will now proceed to describe the apparatus by which a bell may be
rung or other signal given to an approaching or leaving train from a
station. At a distance, say half a mile, from the station there are placed
on the roadway two insulated metallic contact plates 2ª and 4ª, Fig. 9, to
correspond in position with the metallic contacts 2 and 4 on the train.
These contact plates 2 and 4ª are connected by insulated wires with a
battery in the signal box at the station, having a switch to make or
break the circuit (see Fig. 9). If the switch is on the contacts 2 and 4
of any train, being themselves metallically united, and having an electric
bell in circuit, as the train passes over the contact plates 2ª and 4ª will
either cause the bell to ring on the train, or any other signal may bo
given as soon as the contacts 2 and 4 touch the contact plates 2 and 4ª.
The switch should always be on, and only taken off when the person in
charge of the station signal box has assured himself that the road about
the station is clear, so that no train can approach a station without
having a bell rung on it, unless the signalman or station master or
person in charge specially permits it. This same arrangement may be
used for recalling a train after it has left a station by having plates 2*
and 4 suitably placed with the wires going backwards to the station
from which the train loaves. The arrangement of the wires in con-
nection with all the above apparatus will be readily understood by an
inspection of Fig. 9 of the Drawings.

page_text: Thirdly. The apparatus herein-before described which I have called
he road apparatus, and which is represented in Figs. 2, 3, 4, 5, 6, and 7
f the Drawings hereunto annexed.
In witness whereof, I, the said George Whyte, have hereunto set
my hand and seal, this Twenty-first day of October, in the
year of our Lord One thousand eight hundred and seventy-
four.