IMPROVEMENTS IN SIGNALLING APPARATUS ESPECIALLY APPLICABLE TO FOG SIGNALLING FOR RAILWAY AND PROVISIONAL SPECIFICATION
Year: 1882

page_text: LETTERS PATENT to William Edward Langdon of 5 Grove Terrace Derby
in the County of Derby, Superintendent of the Midland Railway Company's
Telegraph Department for an invention of "IMPROVEMENTS IN SIGNALLING
APPARATUS ESPECIALLY APPLICABLE TO FOG SIGNALLING FOR RAILWAY AND
PROVISIONAL SPECIFICATION left by the said William Edward Langdon
at the Office of the Commissioners of Patents on the 20th May 1882.
WILLIAM EDWARD LANGDON of 5 Grove Terrace Derby in the County of
Derby, Superintendent of the Midland Railway Company's Telegraph Department
"IMPROVEMENTS IN SIGNALLING APPARATUS ESPECIALLY APPLICABLE TO FOG SIG-
NALLING FOR RAILWAY AND OTHER PURPOSES
"
This invention has for its object the provision of such an arrangement as shall
admit of the signalman or other person in charge of the line or outdoor signals
governing the movement of railway trains or other vehicles bringing into operation
at will at a given point on the passing of a train or otherwise an audible signal.
To this end I provide an electrical wire between the signal station and the
signalling point, and I connect the same at the signalling point which may be at
a fixed signal post or at any given point independent of a signal post, to a relay;
and at the signal box to a commutator and battery, by which the relay may be
brought into use at the discretion of the signalman.
I employ this relay to bring into operation a local circuit. In this local circuit
I provide a commutator actuated by the passing train, together with certain
apparatus affording an audible signal comprising either a bell or gong, bells or
gongs of varying notes, or a detonator or fuse giving a loud report or other audible
signal or alarum. Where a signal post is employed the expression of this audible
signal is dependant upon the position of the armature of the relay, the position of
the signal, and the passing of the train over a given point. Where no signal post
exists it is dependant upon the position of the armature of the relay, and the
passing of the train only. And in either case I am enabled by connecting the line
wire between the relay and the signal box to the block signal instrument governing
•

page_text: trains proceeding in the direction for which the signal is employed to render the
action of the audible signal dependant, with or without the discretion of the signal-
man, upon the electric block signals.
To sound the bell or gong I employ a train of wheels impelled by a powerful
spring or weight to bring into action one or more levers or bell hammers, which
train of wheels is set in motion by the armature of an electro-magnet included in
the local circuit and brought into action on the train passing over a certain point
at which I cause it to actuate a commutator forming part of the said local circuit,
and to ignite the fuse or detonator I employ an electro magnet setting in motion
certain mechanism which brings into a powerful battery circuit the fuse or fuses
required to be ignited
For the purpose of affording signals of a distinguishing character I provide where
a bell or gong is employed, a combination or series of blows on the bell or gong
with varying intervals of time between or I employ bell domes differing in note,
so that either by repeated single blows upon a bell, or by a given combination of
blows with varying intervals of time between, or by blows given alternately upon
bell domes of different note the signal required to be rendered may be distinguishable
to the passing vehicle all such signals being applicable as required to any position
of the signal, or to indicate whether the line is clear or whether it is blocked.
And where detonators are employed I provide for the explosion of one or more
.in succession.
In order to reset the gong mechanism preparatory to a following train I make
use of the depression of the metals or a bar or part in connection with the line by
the passing vehicle to bring into use certain levers rods and ratchets by means of
which the mechanism is again wound up to its required condition; and an electrical
commutator for the adjustment of the detonator apparatus.
In illustration let it be assumed that a train is travelling from A to C. At B
a point intermediate between A and C is placed the apparatus herein referred to
for affording the audible signal. Now on the train approaching B it brings into
action the electrical commutator placed in the local circuit, the mechanism for
discharging the bell or the detonator is thereby in conjunction with the other
portions of the apparatus as previously explained brought into operation and the
required signal whether by gong or detonator produced.
As the train or vehicle passes the structure containing the mechanism it actuates
a lever or part placed in connection with the metals and connected by rods to a
ratchet by the movement of which the mechanism is reset ready for a following
train.
But when a detonator signal is employed at a given point after passing the said
structure the train there actuates an electrical commutator by means of which the
apparatus applicable thereto is adjusted.
The audible signal thus brought into operation may be employed to give any
signal required and not necessary to indicate danger only.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Edward Langdon in the Great Seal Patent Office on
the 20th November 1882.
WILLIAM EDWARD LANGDON of 5 Grove Terrace Derby in the County of
Derby Superintendent of the Midland Railway Company's Telegraph Depart-
ment. "IMPROVEMENTS IN SIGNALLING APPARATUS ESPECIALLY APPLICABLE TO
FOG SIGNALLING FOR RAILWAY AND OTHER PURPOSES
"
This invention has for its object the provision of such an arrangement as shall
admit of the signalman or other person in charge of the line or outdoor signals
governing the movement of railway trains or other vehicles bringing into
operation at will at a given point on the passing of a train or otherwise an audible
signal.
To this end I provide an electrical wire between the signal station and the
signalling point and I connect the same at the signalling point which may be at
the fixed signal post or at any given point independent of a signal post-to a
relay; and at the signal box to a commutator and battery, by which the relay may
be brought into use at the discretion of the signalman.
I employ this relay to bring into operation a local circuit. In this local circuit
I provide a commutator actuated by the passing train together with certain
apparatus affording an audible signal comprising either a bell or gong, bells or
gongs, of varying notes, or a detonator or fuse giving a loud report or other
audible signal or alarum. Where a signal post is employed the expression of this
audible signal is dependant upon the position of the armature of the relay, the
position of the signal and the passing of the train over a given point. Where no
signal post exists it is dependant upon the position of the armature of the relay
and the passing of the train only. And in either case I am enabled by connecting
the line wire between the relay and the signal box to the block signal instrument
governing trains proceeding in the direction for which the signal is employed to
render the action of the audible signal dependant-with or without the discretion
of the signalman-upon the electric block signals.
To sound the bell or gong I employ a train of wheels impelled by a powerful
spring or weight to bring into action one or more levers or bell hammers which
train of wheels is set in motion by the armature of an electro magnet included in
the local circuit and brought into action on the train passing over a certain point
at which I cause it to actuate a commutator forming part of the said local circuit;
and to ignite the fuse or detonator I employ an electro magnet setting in motion
certain mechanism which brings into a powerful battery circuit the fuse or fuses
required to be ignited.
For the purpose of affording signals of a distinguishing character I provide where
a bell or gong is employed a combination or series of blows on the bell or gong
with varying intervals of time between.
Or I employ bell domes differing in note so that either by repeated single blows
upon a bell or by a given combination of blows with varying intervals of time
between, or by blows given alternately upon bell domes of different note the signal
required to be rendered may be distinguishable to the passing vehicle, all such
signals being applicable as required to any position of the signal, or to indicate
whether the line is clear or whether it is blocked.
And where detonators are employed I provide for the explosion of one or more
in succession.
In order to reset the gong mechanism preparatory to a following train I make

page_text: use of the depression of the metals or a bar or part in connection with the line by
the passing vehicle to bring into use certain levers rods and ratchets by means of
which the mechanism is again wound up to its required condition; and an electrical
commutator for the adjustment of the detonator apparatus. The audible signal
thus brought into operation may be employed to give any signal required and not
necessarily to indicate danger only.
"
And in order that this my invention may be more fully understood I will now
describe the same with reference to the accompanying drawings and firstly with
regard to my Gong or Bell signals
Figure 1 is an end view, Figure 2 a plan and Figure 3 a vertical cross section on
line A A Figure 2 of an apparatus containing a train of wheels impelled by a
powerful spring or springs within the barrel Q in the ordinary way-Upon one
end of the spring barrel shaft A is fixed a ratchet wheel B and fixed on the
barrel is the fly or pin wheel C. In gear with the ratchet wheel B is arranged
a vertical tooth rack D, connected with a lever E centred at F which at its other
end is keyed to the railway metal G.
On the periphery of the pin wheel C are provided at such distances as may be
required, holes for the reception of pins c, c', c¹ &c so that such pins may be
arranged consecutively or in a series of any number with any required space
between. These studs c c¹ c¹¹ &c according to their arrangement at the periphery
of the wheel C, operate on bell crank levers H H' which by wires are connected to
the hammer levers H2 H3 Figure 4 causing them to strike the bell domes I l¹
Figures 4 and 6 producing audible signals which are of different sounds or notes.
K, Figures 2 and 3 is an electro magnet included in the circuit from a local
battery Ğ Figure 6 and having in connection with its armature La detent M
which engages with the stop lever N Figures 1, 2 and 3. This lever turns on a
fulcrum at N¹ and is provided with a spoke wheel n Figures 2 and 3 having
pegs n' and n² and a small ratchet wheel n³ in one therewith and both loose on a
centre pin but held by a helical spring which tends to bring the spoke wheel n
back into its original position when the spring pawl n is released from the ratchet
wheel n by reason of the lever n coming against the stop me. The lever N is
raised at one end by the pin c³ &c on the wheel C coming in contact with a spoke
of the wheel n when it is in a locked position, the opposite end of the lever N is
then depressed and brought into gear with the detent M and held thereby. On a
current of electricity passing through the electro magnet K its armature L is
attracted and its opposite or detent part M then releases the stop lever N and the
wheel C makes one or more complete revolutions, when, unless the armature L is
still held by the current the mechanism is brought to a stop.
The lever E Figures 1 and 2 is rigidly fixed to the railway metal G, so that it
shall move with it. On G being depressed by a wheel of a passing train or
locomotive the rack D is raised, and being held by the spring D against the ratchet
wheel B engages with it, and by its upward movement winds up the spring
attached to the spindle A and contained in the barrel Q. On the rail G resuming
its normal condition the rack D will descend, whilst the spindle A being incapable
of revolving otherwise than in the direction of the arrow Figure 1 will be retained
in its position.
In the neighbourhood of the pin wheel C is placed a spring O Figures 1 and 3
and beneath it a contact stud P so arranged that when the wheel C is at rest O
and P are separated but when C is revolving the pins c, c², c² as they revolve press
the spring O into contact with P. I employ this (as will be shown hereafter with
reference to Figure 6) to repeat back to the Signal box or other possition accessible
to the officer responsible for working the line signal or gong the due action of the
said electrical gong.
To the signal post I attach an ordinary commutator, such as is in use for
repeating to the point from which the signal is worked, the position of the signal
whether at "Danger" or "All Clear."
In the signal box or at the point whence the signal is worked, I place a tell tale

page_text: instrument as shown at A Figure 6 having a needle or bell operated by an electric
current subject to the movement of the wheel C at B Figure 6. When no current
is flowing through this instrument the needle a stands as shown in full line in
Figure 6, but during the time the current is flowing the needle a is carried over
to the dotted position and the bell dome b struck thus affording an aural as well
as a visual signal at the action of the gong at or forming the distant signal.
I employ these several arrangements wholly or in part as may be required
either;
1. In connection with the Block Telegraph Instrument for the section to be
protected, as shown in Figure 5 where A represents the block instrument and B a
switch or commutator both within the signal box; and at the signal post an ordinary
relay C having a needle carrying a contact piece c playing between its poles
forming as may be desired according to the direction of the electric current contact
with the studs d or d¹ but standing vertical at such times as no current is passing;
E is a commutator or contact maker at the signal post; H is a commutator or
contact maker in connection with the Railway metal; F and F¹ are the signal
gongs and G the battery.
Now these several parts being connected up as shown in this diagram Figure 5
the Line Blocked current from the distant block post will pass through the
instrument A and if the switch B be placed in such a position as to connect the
wire from the instrument A with that leading to the Relay C at the Signal Post
it will place the Relay needle C in contact with the stud d' which will complete
the connection between the wire from the contact maker E and that attached to
the stud d¹ and the signal in connection with the commutator E being in the On
position as shown the circuit will be complete between the Rail Commutator H
and d' From d' a wire leads to the Electro magnet K and thence to the battery G
from the opposite pole of which a wire connects with the contact maker H The
circuit is thus complete at all points except at the rail contact maker H.
Now on a train or locomotive passing in the direction A B C over this contact
maker it will depress the rail and so bring the springs of the contact maker H
together fully completing the circuit. A current will then pass from the battery G
through the Electro magnet K the mechanism described with reference to figure 1, 2
and 3 will be put in motion the rack D will be raised and cause the ratchet
wheel B and pin wheel C to revolve whereby the bell crank lever H or H¹ will be
pulled and the gong will sound a certain number of beats singly or in series
according to the number of pins in the wheel C as may be arranged, indicating a
danger signal.
But should the Block signal indicated be a "Line clear" signal an opposite
current will pass through the Relay C figure 5 and the Relay needle c will be carried
over into contact with the stud d The local circuit will now be formed through
the electro magnet K¹ in connection with the "all clear" gong F and on a train
passing over H the gong F of a different note or giving forth a different series of
beats to F will be sounded indicating an All clear signal.
"
The contact maker employed at H figure 6 is such as is described in the
specification of letters patent granted to me 11th February 1882 No. 667.
II Where it is not required to connect these gongs with Electric Block
Instruments I provide an arrangement such as is shown in Figure 6 where A
represents a tell tale instrument B a switch connecting the instrument A with a
wire leading to the contact maker E working in connection with the distant signal
from the "ON" contact of which a wire is led to the electro magnet K and thence
to the battery G the opposite pole of which is connected to the Rail contact
maker H and thence to earth. From that pole of the battery connected to H a
wire is carried to the stud P. Figures 1. 3 and 6 and from the spring O which
stands free of P, a wire is carried to earth.
Now on the switch B Figure 6 being turned to through and the signal being in
the "ON" position, the circuit will be complete at all points except at the contact
maker H; and on a train passing over this contact Maker the circuit will be fully

page_text: completed the two springs of H being brought into contact. A current will now
flow through the electro magnet K its armature L will be attracted the mechanism
figures 12 and 3, discharged, and the gong or gongs sounded the required number
of times either singly or in series.
On the pin wheel C. Figure 1, 2 and 3 revolving, the studs c c¹ c³ thereon will
depress the spring O placing it in contact with P, and thereby completing during
the passage of the stud over O the circuit between the signal Box at A Figure 6
and the gong at B and a current will be sent through the Tell Tale instrument A
causing its needle to assume the dotted position and the bell in connection with. it
to sound and this action will be repeated during the passage of every stud over the
spring Otherby indicating to the signalman the fact of the due action of the gong
at the distant signal.
In both the preceding and present arrangements the contact maker H in
connection with the Rail is placed at such a distance from the gong at B Figure 6
as will enable its mechanism to be started and the sound of the gong to be emitted
as the train approaches the gong so that the train will in approaching meet the
sound.
On the train passing a point opposite the gong the depression of the Rail
consequent upon the weight of the train will operate the lever E Figures 1, 2,
and 3 and rack D and ratchet B thereby winding up the spring in the barrel Q
which provides the motive power for driving the mechanism.
DETONATING SIGNAL.
III. Figure 7 is a diagram illustrating the means which I adopt in order to
afford a danger signal by discharging on the passing of a train by means of an
Electrical current a detonating signal affording a loud report similar to that at
present obtained from detonating signals when placed upon the railway metals
B is a switch placed at the signal box for the purpose of bringing the arrange-
ment into operation at will, E is the commutator at the signal post, H H¹ are two
commutators in connection with the railway metals, G is the line battery and G¹ a
local battery.
K and K are electro magnets the armatures of which are provided with a pawl
tooth at their extremity which when attracted by the current engage with the ratchet
wheel R but which when un-influenced by the current are free of R; ¹³ ³ are
springs arranged in the radius of the wheel R and connected to plates S S¹ S² S³
and opposite to these plates are other similar plates connected to one pole of the
local battery G' the other pole of the said battery being connected to the wheel R
which is formed of metal.
On the periphery of the wheel R and in metallic contact with it is a metal
stud the object of which is to form contact with the springs r. r¹. r². &c as R is
rotated by the action of the armatures of the electro magnets K K¹. Between each
pair of the plates S S¹ S² &c is placed a detonator or fuse Y which is so formed that
it affords a metallic contact on two opposite sides which metallic contacts are
connected by means of a fine platinum wire which passes through the explosive
material Y and which on combustion produces the detonating report.
The wheel R may be made to any size and any number of contact springs r may
be arranged in the radius formed by the stud v. Each spring connecting with a
detonator clip as shown at S 'S' S² &c.
The contact makers H H¹ in connection with the rail metal are placed at such a
distance apart as shall be sufficient for a train to stand between them.
Now on the switch B being connected through by the pin b being inserted
between the connecting plates and a train passing in the direction C, B, A over
the contact maker H' the battery current from the line battery G will flow through
the electromagnet K¹ the armature of which will be attracted and will move
forward the wheel R one step bringing the stud in contact with the spring r²
when a powerful current from the local battery G¹ will pass through the wire in

page_text: the detonator at S₁ Exploding it and on the train reaching the contact maker H
a current will proceed from the line battery G through the electro magnet K
causing its armature to move the wheel R another step placing the stud v in a
position between the spring and the spring 3 leaving it prepared for a repetition
of the same action in connection with the detonator in circuit with the spring illl
on a following train passing over the contact maker H.
Any number of springs r may be employed in connection with a corresponding
number of clips s and detonators.
And having thus described the nature of this invention and the manner in which
it is or may be performed I declare that I claim.
First The several combinations and arrangements of apparatus substantially
as and for the purposes described and as illustrated by the diagrams Figures 4, 5,
6 and 7
Second-The employment in connection with a rail commutator of apparatus
for rendering a distinguishing code of signals or gong sounds indicating the nature
of the signal as for instance for a main line or branch line, passenger line or goods
line danger signal or all clear signal substantially as set forth.
Third-The employment of such signals as herein secondly claimed in
connection directly by relay or by switch with the Electric block signals
substantially as set forth.
Fourth-The application of the repetition of such signals substantially as and
for the purpose set forth.
Fifth The combination of parts forming the signal actuating mechanism
substantially as described with reference to Figures 1, 2 and 3 whereby a train of
wheels is adapted to the purpose in view.
In witness whereof, I the said William Edward Langdon have hereunto set
my hand and seal the Eighteenth day of November in the year of our
Lord One thousand eight hundred and eighty two
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