IMPROVEMENTS IN APPARATUSES FOR SIGNALLING UPON KAILWAYS.
Year: 1862

page_text: LETTERS PATENT to Charles Frederick Whitworth, of Sowerby Bridge, in
the County of York, Engineer, for the Invention of "IMPROVEMENTS IN
APPARATUSES FOR SIGNALLING UPON KAILWAYS.
PROVISIONAL SPECIFICATION left by the said Charles Frederick
Whitworth, at the Office of the Commissioners of Patents, with his
Petition, on the 2nd May 1862.
I, CHARLES FREDERICK WHITWORTH, of Sowerby Bridge, in the County of
York, Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN APPARATUSES FOR SIGNALLING UPON RAILWAYS," to be as
follows:-
The objects of my Invention are to provide against any liability to collisions,
especially where there are steep gradients, curved cuttings or tunnels, and
other obscure places; to provide a warning of the approach of trains to
stations, junctions, crossings, opening bridges, and other places; to afford
means of ascertaining at any time whether a distant signal is on or off,
although from some local obstruction, fog, storm, or other casualty the signal
itself may be invisible. The peculiar merits of the Invention are that all the
proposed advantages are obtained by combined means so arranged and
effected that very little power and momentum are required to ensure efficient

page_text: action, and the concussion of impact even at the highest velocity of trains is so
slight as to preclude all liability to fracture or derangement in action.
My Invention consists in the arrangement of apparatuses which, by the aid
of electro-magnetism, work signals upon railways, as hereafter referred to.
A loose rail, to be acted upon by the wheels of a passing engine or train, is
connected by a rod to a lever, on the shaft of which another lever is keyed;
the short arm of this last named lever is weighted, while the extremity of the
long arm enters a fork in a vertical rod connected to a second weighted lever.
This lever supports a non-conducting hinged bar, on or through which a wire
in connection with the battery and bell is carried; upon an engine or train
passing over and acting on the loose rail, the loose rail descends in accordance
with the depth of the flange of the wheel, and causes the long arm of the
weighted lever at the further end of the shaft to descend also, with the vertical
forked rod resting thereon, and the lever from which this rod is suspended by
a pin joint. The descent of this last lever lets down one end of the hinged
bar (resting across it) until the wire which it carries makes contact with a
fixed earth or return wire, which completes the circuit, and causes the bell to
ring. In order to ensure the proper action of the apparatus the long arm of
the weighted lever first herein named is connected to the loose liub of a
bellows, to prevent the two rapid return of the loose rail.
When desirable to work sigual arms or lamps, as well as to signalize by
bell, I fix a hollow post for the purpose of bearings and cover for the lamp
and signal apparatus on the top of the frame which forms the bearings and
cover of the weighted levers above mentioned. This hollow post is fixed
immediately over the vertical forked rod. By means of a pin-linked chain the
lever carrying the vertical forked rod is connected to a shorter lever ranged
above it; this last lever carries a red glass, which is capable of intervening
between the light of a lamp to give a red light when required for danger.
From this shorter lever operating the red glass, another chain ascends over
and is fixed to a grooved pulley, keyed on a small shaft passing transversely
to the levers last referred to. To each end of this shaft is fixed a signal arm.
On the small transverse shaft, being the centre of the arms of the signal, is
also keyed a three-armed lever, on one of the arms or branches of which is a
small weight of sufficient power when released to produce a quarter revolution
of the shaft or centre (from which motion an edge view only of the signal arms
is the result), and to lift up the lever operating the red glass until it no longer
intercepts the white light. Near the end of another of these branches,
which I call the stop lever, is a small stud pin which, when near its greatest
elevation, slightly raises a horizontal lever or kind of paul above it, on the

page_text: under side of which paul there is a notch provided to catch and hold this pin
when the shaft or centre has so far moved round as to present to view the red
flat sides of the signal arms indicating danger. The motion of the signal arms
from their edge view indicating all clear," to the broadside view showing
"danger," is obtained as follows:-It may be observed from the above
description of the parts, that the shaft or centre of the signal arms is, by
means of the chain fastened over the grooved wheel thereon, attached to the
short lever operating the red glass, and that this short lever is also joined to
the lever below it. Now, this lever below is so weighted that whenever the
loose rail is pressed down by a passing train or engine (which, by overpowering
the main weight on the short arm of the lower lever, withdraws the support
of the other arm from the fork of the vertical rod), its gravity is sufficicut to
counteract the small weight on the branch lever of the centre of the signal
arms, causing them to revolve so far as will set them to danger, and bring the
stud pin of the other branch lever, called the stop arm, so far under the paul
above-mentioned as to be caught and retained by the notch therein, causing
the signal to remain, indicating danger, until released as follows:-Parallel to
and above the transverse shaft or centre of the signal arms is another small
shaft working in bearings fixed to the sides of the hollow post; across the last-
mentioned shaft, which I call the releasing spindle, rests the further end of
the paul above referred to, when the stud pin is released from its notch, and
the signal indicates "all clear;" but when at " danger" the stud pin of the
stop arm as before mentioned elevates this paul slightly at the loose end, where,
as in the stop arm, there is also a small lateral pin or stud. On the releasing
spindle a short curved arm is so adjusted under the stud pin of the paul by
means of a set screw, that when the spindle partially revolves from its normal
position, the curved arm, coming in contact with the stud pin, lifts up the
paul to release the pin of the stop arm from its notch.
The power and motion of the releasing spindle are thus obtained :-On the
spindle and near one end is fixed a small weighted arm, capable of being
adjusted for more or less power. When this weighted arm is nearly vertical,
but just beyond the centre, it rests against a stop, which prevents a further
revolution of the spindle in that direction, while a lower stop is fixed in the
opposite direction to prevent the motion of this spindle exceeding about a
quadrant. The normal position of the weighted arm is nearly vertical, as it
rests back against the upper stop; but on the same spindle is fixed a short
slight arm, set nearly even with the weighted arm, and close behind the short
arm just named, suspended from a hinged joint above, is a small thin lever,
near the top of which is fixed the keeper of a magnet, placed in position and

page_text: connected with wires to a battery, that whenever the circuit is completed for
this purpose, the magnet in attracting its keeper causes the suspended lever to
act against the short arm to pull over the weighted arm of the releasing
spindle from its upper stop until gravity over the centre in causing a further
motion of the spindle, brings the curved lever before mentioned with force
under the stud pin of the paul, which it thus lifts up, releasing the pin from
its notch, and permitting the signal to revolve to "all right." From the
centre of the curved lever, last named, a longer curved arm is extended in an
opposite direction, and so applied that when the releasing spindle has so far
revolved as to set the signal shaft at liberty, a stud from the third branch of
the lever before mentioned, as keyed on the signal shaft, comes in contact with
this longer curved arm, and, as the shaft revolves, resets the releasing spindle
with its weighted arm reclining against the upper stop, and retained there
until the signal is again set to danger. One end of the wire continued from the
magnet is united to an insulated brass lever, while the other end of this lever, so
long as the signal is indicating danger, rests upon a piece of conducting metal,
connected to a return wire, which then forms the connection here; but when
the signal is all clear an excentric lever or projection, of bone or other non-
conducting substance, fixed on the shaft of the signal arms, lifts up the end of
the brass lever to break the contact with the return wire at this place; thus,
when the signal is "on" the wires here will be in contact, but when "off"
they will be disjoined. But there is a second break of wires at the station or
other part where it is desirable to operate on the signal; contact is made and
circuit with the battery completed at this second place at option, either by a
manual operation or by the operation of the train on a second application of
the loose rail and apparatus first mentioned for ringing the bell. Either of
these modes of effecting this contact will immediately release the signal, and
the bell in connection will ring until contact is broken by the action of the
non-conducting excentric on the brass lever, as the signal revolves to "all
right." As regards resetting the signal to "danger," either from the station
or other part of the line in an emergency, I use another magnet with wires,
battery, releasing spindle, and other parts (somewhat similar in character to
those herein-before mentioned), to act on and release a second counter revolving
shaft or lever of sufficient power, when brought into action, to cause the arms
to assume the position indicating danger.
Where the distance between the operator and the signal is only short, I
prefer resetting the signal to danger in an emergency by means of an ordinary.
hand lever and connections, joined at the other end to a lever from the shaft,
on which the long lever, which works within the vertical forked rod is keyed,.
.

page_text: as above mentioned; but in this case a counterweight is arranged beyond this
shaft of sufficient power to draw back so far as to leave the lever on the shaft
perfectly free to operate with it when the signal is not actually held at danger
by the hand lever for special purposes.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Charles Frederick Whitworth, in the Great Seal Patent
Office on the 1st November 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
FREDERICK WHITWORTH, of Sowerby Bridge, in the County of York, Engineer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Second day of May, in the year of our Lord
One thousand eight hundred and sixty-two, in the twenty-fifth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Charles Frederick Whitworth, Her special licence, that I, the said
Charles Frederick Whitworth, my executors, administrators, and assigns, or
such others as I, the said Charles Frederick Whitworth, 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 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 "IMPROVEMENTS IN APPARATUSES FOR SIGNALLING
UPON RAILWAYS," upon the condition (amongst others) that I, the said Charles
Frederick Whitworth, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, should par-
ticularly 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
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Charles Frederick Whitworth, do
hereby declare the nature of my 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, reference being had to the Drawings here-
unto annexed, that is to say:
The objects of my Invention are, to provide against any liability to collisions

page_text: especially where there are steep gradients, curved cuttings, or tunnels, and
other obscure places; to provide a warning of the approach of trains to
stations, junctions, crossings, opening bridges,, and other places; to afford
means of ascertaining, at any time, whether a distant signal is on or off,
although, from some local obstruction, fog, storm, or other casualty, the signal
itself may be invisible. The peculiar merits of the Invention are that all the
proposed advantages are obtained by combined means so arranged that very
little power and momentum are required to ensure efficient action, and the
concussion of impact, even at the highest velocity of trains, is so slight as to
preclude all liability to fracture or derangement in action.
My Invention consists in the arrangement of apparatuses which, by the aid
of electro-magnetism, work signals upon railways as hereafter. explained,
reference being had to the Drawings hereunto annexed.
Figure 1 shews a sectional side view, and Figure 2 a front view of parts of
apparatus according to this part of my improvements. A loose rail or arın
a in position to be acted upon by the wheels of a passing engine or train is
connected by a rod b to a lever c, affixed to the shaft c', on which is affixed
another lever d; the short arm of this last-named lever d is weighted,
while the end of the larger arm thereof enters a fork el, formed in the vertical
rod e, which at its upper end is connected by pin joint e² to a second weighted
lever f. This lever f supports a conducting hinged bar g, on or through which
a wire g', in connection with a suitable battery and bell apparatus is carried.
Upon an engine or train passing over and acting on the rail or arm a, that
rail or arm will be depressed, causing the long arm of the weighted lever at
the further end of the shaft to descend with the vertical forked rod e resting
thereon, and the lever f from which this rod is suspended.
The descent of
this last lever lets down one end of the hinged bar g (resting across it and
insulated therefrom) until the wire g' which it carries makes contact with an
earth or return wire which completes the circuit and causes a bell to ring. In
order to insure the proper action of the apparatus the long arm of the weighted
lever d is connected to the loose limb of a bellows h, so that when that lever
d is being depressed air will flow through a suitable valve into the bellows h,
and on the return of the lever & the air being allowed to escape from the
bellows only by a comparatively small hole capable of being regulated, the time
of return of the parts will be controlled. When desirable to work signal arms
or lamps as well as to signalize by bell I connect the lever f to a shorter lever i
ranged above it by means of a chain . This lever i fixed on the shaft *
carries a red glass, which is capable of intervening between a gas or other
light and the clear glass L, to give a red light when required for "danger." From

page_text: this shorter lever i operating the red glass
another chain ascends over and
is fixed to a grooved pulley keyed on a small shaft . To each end of this
shaft is fixed a signal arm j, j. On this small transverse shaft is also
keyed a three-armed lever k, on one of the arms or branches of which is a
small weight of sufficient power when released to produce a quarter revolu-
tion of the shaft ", by which motion an edge view only of the signal arms is
the result, and to lift up the lever operating the red glass until that glass no
longer intercepts the white light. Near the end of another of these branches,
3, which I call the stop lever, is a small stud pin k', which, when near its
On the under side.
greatest elevation, slightly raises a lever or pall Z above it.
of this lever or pall 7 there is a notch provided to catch and hold this pin ', .
when the shaft 2 has been so far moved round as to present to view tho red:
flat sides of the signal arms j. j, thereby indicating "danger." The motion:
of the signal arms j, j, from their edge view indicating "all clear" to the broad.
side view showing "danger " is obtained as follows:-It may be observed from
the above description of the parts that the shaft of the signal arms is by
means of the chain fastened over the grooved wheel, attached to the short.
lever i, operating the red glass, and that this short lever i is also connected
by the chain to the lever f; this leverf is so weighted at f¹ that whenever
the rail or arm a is pressed down by a passing train or engine, which by over-.
powering the main weight d on the short arm of the lower lever d with-.
draws the support of the longer arm of the lever d from the fork e¹ of the
vertical rod e, its gravity is suflicient to counteract the small weight on the
branch lever k¹, on the axis ", of the signal arms j,j, causing those signal arms:
to revolve so far as will set them to indicate "danger," and bring the stud pin
of the other branch lever, called the stop arm, so far under the pall as to
be caught and retained by the notch ' therein, causing the signal to remain
indicating danger" until released as follows:-Parallel to and above the
shaft of the signal arms j, j, is another shaft m, working in bearings carried,
by the framing. Across this shaft m, which I call the releasing spindle, rests
the further end. of the pall when the stud pin k is released from its notch ',
and the signal indicates "all clear," but when at "danger" the stud pin of
the stop arm elevates this pall slightly at the loose end, where, as in the.
stop arm, there is also a small lateral pin or stud 12. On the releasing
spindle a short curved arm m' is affixed under this stud pin 12 of the
pall, so that when the spindle m partially revolves from its normal :
position, the curved arm m', coming in contact with the stud pin 1, lifts
up the pall to release the pin k of the stop arm from its notch .
The power and motion of the releasing spindle m are thus obtained:-On,
66

page_text: this spindle m, near one end of it, is affixed a small weighted arm m³, the
weight on which is capable of being adjusted for more or less power.
When this weighted arm m³ is nearly vertical, but just beyond the centre,
it rests against a stop n, which prevents a further revolution of the spindle m
in that direction, whilst a lower stop n¹ is fixed in the opposite direction
to prevent the motion of this spindle m exceeding about a quadrant. The
normal position of the weighted arm m³ is nearly vertical as it rests against
the upper stop ; but on the spindle m is fixed a short slight arm o, and close
bebind this short arm o is a lever p, which is suspended from a hinged joint p',
and near the top of this lever p is fixed the keeper q' of a magnet q, which
magnet is placed in position and connected with wires q, q³, to a battery, so
that whenever the circuit is completed for this purpose, the magnet, in
attracting its keeper, causes the suspended lever p to act against the short
arm o, to pull over the weighted arm m³ of the releasing spindle m from its
upper stop n until its gravity over the centre in causing a further motion of
the spindle m brings the curved lever m² with force under the stud pin of
the pall 7, which it thus lifts up, releasing the pin from its notch & permitting
the signal arms j, j, to revolve to "all clear." From the centre of the curved
lever a longer curved arm m is extended in an opposite direction, and so
applied that when the releasing spindle m has so far revolved as to set the
signal shaft at liberty, a stud k from the branch of the lever k, keyed on the
signal shaft 2,comes in contact with this longer curved arm m', and as the shaft
revolves, re-sets the releasing spindle m with its weighted arm m³, reclining
against the upper stop n, retaining it until the signal is again set to "danger."
One end of the wire q, continued from the magnet q, is united to a conducting
lever 1, whilst the other end of this lever r, so long as the signal is indicating
"danger," rests upon a piece of conducting metal s, connected to a return
wire s', which then forms the connection here; but when the signal is "all
clear," an eccentric lever or projection t, fixed on the shaft of the signal
arms, lifts up the lever r, from which it is insulated, and breaks the contact
with the return wire s' at this place, thus when the signal is "on," or indicating
danger," the wires s' and q will be in magnetic contact, but when "off" or
indicating "all clear" they will be disjoined. But there is a second break of
wires at the station or other part, where it is desirable to operate on the signal.
Contact is made and circuit with the battery completed at this second place
at option, either by a manual operation or by the operation of a train on a
second application of the loose rail.
6
Figures 3 and 4 show side and sectional views of apparatus placed at the
distance required for protection by the signal arranged according to this part

page_text: of the Invention, in this case the shaft c¹ being acted upon by a loose rail
depresses the lever arm d, which in its descent lets down one of the hinged
conducting bar g* which is connected to a wire from a battery, and in its
descent comes in contact with a piece of metal connected by means or the
wire and the main wire w¹ to the wire q, and through q and w² to the
battery, completing the circuit, Figures 1 and 2, thereby setting in action
the magnet q as before described. The conducting lever g* is insulated where
it comes in contact with the lever d. To set the signal to "danger" at a
distance for shunting or other cases of emergency, when that distance does not
far exceed three-quarters of a mile, I prefer using an ordinary hand lever.
with wire A, Figure 5, connected to a kind of link or slotted bar B passed
over the top of a lever C (fixed on the axis c¹) between guide pins D, D. The
link B is connected by a pin joint to a rod E, which is also connected to the
shorter arm of the lever F. This lever F is on a short post F and weighted
sufficiently to draw back the wire from the band lever above mentioned after
use to its normal position, the link B then permitting free motion to the
lever C and the shaft C'. But whenever the wire and link are drawn forward,
the end of the link B presses against and pushes forward the lever C, thereby
causing a motion of the shaft C¹ and the lever d, Figures 1 and 2, like that
produced by the action of the flange of a passing wheel, which motion sets the
signal to "danger" as herein above described; but when the interval between
the signal and the further end of the tunnel or other distant point from which
it is required to set or release such signals is a mile or more, I prefer using a
small cranked spindle u, Figures 1 and 2, which is acted upon by a weight u¹
suspended by a chain or cord u² winding round the pulley u fixed on the
spindle u, so that the weight will cause a revolution of the cranked spindle
whenever it is released as hereafter shown for this purpose. The crank u is
connected by a vertical rod-u³ to the lever fixed on the shaft * on which is
keyed the lever i carrying the red glass and the stroke of the crank in its
revolution is such as to draw down the lever us and thereby the lever i, until
the pin of the stop lever ³ has passed under the notch in the pall Z, which
will then retain the signal at "danger." The vertical rod is slotted where
it joins the lever u in order not to interfere with any required motion of that
lever whilst the crank is at rest. The crank is retained at rest by the arm u
resting in the notch w of the lower pall w'. Above this pall I fix a magnet x
with a pendant keeper a¹, and releasing spindle and other arrangements
similar to those described above for releasing the upper pall 7. This magnet
when influenced by connecting its wires with a battery of sufficient power, by
attracting its keeper a³, pulls over the releasing spindle x² from its rest by.

page_text: "
upon the piece of metal S, that
means of the lever a³ and the arm at, thus causing the arm to raise the
pall w which then releases the arm u² of the cranked spindle u, and permits
the weight to cause the revolution of the crank u' which sets the signal to
danger "as herein-before explained. The return of the releasing spindle a
to its normal position with its weighted armresting against its upper stop
is effected by the action of the bottom portion y of the frame carrying the red
glass 2 against the small arm which is thus pushed downwards until the
weighted arm again rests against its stop. For the three perfect operations
of indicating the approach of trains when yet at a distance setting the distant
signal to all clear" and ascertaining whether the signal be "on" or not at
any time and for setting the signal to "danger" in emergency, I use five main
wires w¹, w, w³, w, and w³. These wires are suspended from insulated
bearings and terminate in insulators affixed to a post a few feet beyond the
signal. wis connected at I with the wire to the upper magnet 7; w³ is
connected at 2 with the wire s' from the same magnet only when a contact is
made by the descent of the conducting lever
is, whenever the signal is indicating "danger." This wire w² is also connected
at 3 through the wire g¹ to the conducting bar y, which makes connection with
a wire g² only whilst the lever d is being depressed by a passing train; the
wire 92 terminates in a coil round the weighted arm d' of the lever d, and
acts as a return or earth wire. ³ is connected at 4 with a wire to the lower
magneta; and w* is connected at 5 to a return wire from the same magnet; w³
a test wire is connected at 6 with the wire 7, which is connected to the con-
ducting lever 8, which is insulated where it rests on the frame y, which lever
whenever the signal is indicating "danger" rests upon a piece of conducting
metal 9 which is attached to an earth wire 10; by this means the person at
the station having charge of the signals can ascertain by connecting the wire w
with the battery, whether the signal is indicating "danger" or "all clear."
The main wires above mentioned are connected in the ordinary well known
mode with their respective batteries, bells, and apparatus at the place required
for receiving the announcement of trains by bell and for setting or releasing
the distant signal to which they refer, but this part of the arrangement being
no part of my improvements and well known it is unnecessary to describe. These
parts being duly arranged with batteries of power in proportion to the distance
through which it is required to operate, the bell will ring as every train passes
the distant signal because the circuit will be then completed with the battery
by the lever g connecting the wire g¹ from the main wire w² to the earth wire g².
The signal also being set to "danger" as above described by the approaching
train, the main wire w¹ will be in contact with the return wire w², so that when

page_text: contact is also made at the break near the battery so as to complete the
circuit with the return wire w, the bell will ring for a moment, that is, until
the upper magnet bas duly acted on the releasing spindle m and thus set the
signal to "all clear" again.
Similar arrangements may also be applied to any ordinary distant signals for
ascertaining whether they are indicating "danger" or "all clear," the signals
when on or indicating "danger" making connection with test wires leading
thence to batteries and bell apparatus at the station, and when off breaking
such connection by means of a conducting lever apparatus, such as shown at
Figures 3 and 4, acted upon by the rise and fall of the weighted lever of the
signal, but insulated therefrom. The ordinary wires working such distant
signals may be used as the means of connection with the batteries and bell at
the station. These wires also extended to points beyond the distant signal may
be used in connection with batteries and bells at the station and apparatus at
the other end, such as shown at Figures 3 and 4, for announcing that
trains are passing such points whether in approach or departure from the
station.
Having thus described my Invention and means which I adopt in carrying
the same into effect, I declare that I do not confine myself to the precise
details as shown and described as variations may be made therein without
departing from the peculiar character of the improvements, nor do I claim the
various mechanical parts separately considered; but what I do claim is the
adaptation or combination of means for signalling on railways substantially as
explained.
In witness whereof, I, the said Charles Frederick Whitworth, have
hereunto set my hand and seal, this First day of November One
thousand eight hundred and sixty-two.
C. F. WHITWORTII. (L.S.)