IMPROVEMENTS IN RAILWAY SIGNALLING APPARATUS
Year: 1874

page_text: LETTERS PATENT to Josiah Latimer Clark and Edward Jacob Hill,
both of Victoria Street, in the City of Westminster, for the Inven-
PROVISIONAL SPECIFICATION left by the said Josiah Latimer Clark
and Edward Jacob Hill at the Office of the Commissioners of
Patents, with their Petition, on the 14th February 1874.
We, JOSIAH LATIMER CLARK and EDWARD JACOB HILL, both of
Victoria Street, in the City of Westminster, do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN RAILWAY SIGNALLING APPARATUS,"
to be as follows :-
Our Invention relates to the method of signalling the driver of a
railway train by an audible signal on the locomotive, and consists in
improvements in the mechanism by which the said signal is sounded.
This mechanism consists of a frame attached to the buffer plank, or in
other convenient position on the engine, in which a swinging bar or

page_text: trigger is suspended and hangs down centrally, so as to come in contact
with an arm standing up between the rails, as hereafter described, the
trigger being free to swing to and fro in the longitudinal direction of
the engine. In its normal position the trigger hangs perpendicularly,
and supports in a horizontal position a weighted bar or lever, so con-
nected to the whistle of the engine that when the weighted lever falls
it will open the whistle and give an audible signal. To support it
the horizontal position this weighted lever may either rest directly
upon the top of the trigger or its tail end may take under a lug on the
said trigger. In either case it falls when the trigger is struck either
backwards or forwards. In shutting off the whistle the driver necessarily
raises the lever to its horizontal position, and the trigger having passed
over the obstacle by which it was tripped regains its perpendicular
position, and coming under the horizontal lever resets it in readiness for
giving a fresh signal. This apparatus may either be temporarily or
permanently attached to the engine. In the latter case it is preferred
to have a separate steam whistle and cock attached to a pipe led down
beneath the engine. The plug of the cock is prolonged and furnished
with a pulley and weight sufficient to open the cock when released.
An arm is also fixed on the same plug or axis, and when raised is
supported in that position by the trigger, which comes under or engages
therewith, as before mentioned.
The cock is shut off by the engine driver pulling a cord, which at same
time raises the arm, and the trigger being self-setting, as before described,
the cock is kept shut until the trigger is tripped by coming in contact
with the bar in the road, as before mentioned, when the arm being
released the weight is allowed to fall and open the whistle, which con-
tinues to sound until again closed by the act of the engine driver.
A gong may be employed instead of a whistle sounded by a spring
and train.
The device by which the lever is tripped consists of a small bar or
lever mounted on a horizontal axis supported in suitable bearings fixed
to the ground at the middle of the track, and, say, at a suitable distance
in advance of the ordinary distant signal. This device may either be
worked by a continuation of wire working the distant signal or by

page_text: the trigger on any locomotive passing over it and sound the whistle or
gong, as before described. When the distant signal stands at line clear
the bar lies down out of the way of the trigger.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Josiah Latimer Clark and Edward Jacob Hill in
the Great Seal Patent Office on the 14th August 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JOSIAH
LATIMER CLARK and EDWARD JACOB HILL, both of Victoria Street, in
the City of Westminster, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fourteenth day of February, 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 we, the said Josiah Latimer Clark and Edward
Jacob Hill, Her special licence that we, the said Josiah Latimer Clark
and Edward Jacob Hill, our executors, administrators, and assigns, or
such others as we, the said Josiah Latimer Clark and Edward Jacob Hill,
our 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
RAILWAY SIGNALLING APPARATUS," upon the condition (amongst others)
that we, the said Josiah Latimer Clark and Edward Jacob Hill, our exe-
cutors or administrators, by an instrument in writing under our, 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 immediately
after the date of the said Letters Patent.
NOW KNOW YE, that we, the said Josiah Latimer Clark and Edward
Jacob Hill, 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, reference being

page_text: had to the accompanying Sheet of Drawings, and to the letters and
figures marked thercon (that is to say) :-
Our Invention relates to the method of signalling the driver of a
railway train by an audible signal on the locomotive, and consists in
improved mechanism by which the said signal may be given. This
mechanism consists of a frame attached to the buffer plank, or in other
convenient position on the engine, in which a pendulous rod or trigger
is hung centrally, so as to come in contact with an arm standing up
between the rails, as hereafter described, the trigger being free to swing
to and fro in the longitudinal direction of the engine. In its normal
position the trigger hangs perpendicularly and supports on an horizontal
position a weighted bar or lever, so connected to the whistle of the
engine that when the weighted lever falls it will open the whistle and
give an audible signal. To support it in the horizontal position this
weighted lever may either rest directly upon the top of the trigger or
its tail end may take under a lug on said trigger. In cither case it falls
when the trigger strikes the arm before mentioned in whichever direc-
tion the engine may be travelling. In shutting off the whistle the
driver necessarily raises the lever to its horizontal position, and the
trigger having passed over the obstacle by which it was tripped regains
its perpendicular position, and coming under the horizontal lever resets
the apparatus in readiness for giving a fresh signal.
In order that our Invention may be more readily understood we have
illustrated in the accompanying Drawing the arrangement of weighted
lever and trigger, and the arm for tripping the same.
Figure 1 is a front view; and Figure 2, a longitudinal section of
one arrangement. A is a metal frame fitted in guides B, B, bolted
to the engine framing, so as to be readily removable; C is the
weighted lever arm pivoted at B to frame A, and working in a vertical
slot A¹ in said frame; E is the trigger, hung on a pin F, so as to
swing in a longitudinal direction, as shown in dotted lines. The
trigger is slightly hollowed or notched at the top end for the arm C to
lie in, and the lower part of said trigger is a flat spring blade, which
will yield sufficiently when it strikes an obstacle to avoid breakage when
the engine is travelling at a high speed. The lever C is connected at its
weighted end to the lever handle of the steam whistle cock by chains
and pulleys, or rods and bell-crank levers, or other suitable connections,
as will be readily understood, so that when the lever C falls the cock

page_text: shall be turned on to sound the whistle. It will be obvious that instead of
sounding a whistle the cock might be applied to a steam or atmospheric
brake apparatus, and the movement of the cock be used for putting on
the brakes.
Figure 3 shows a slight modification of the foregoing arrangement.
In this case the weighted lever C is on a fulcrum at D, and instead of
resting on the trigger E, as before described, it has a tail end, which
takes under a lug E¹ on the trigger E, the under side of the said lug
being hollowed or notched to prevent the weighted lever being
accidentally released by the jolting of the engine; the action is the same
as before described.
This apparatus may if desired be permanently attached to the engine
and have a separate steam whistle and cock attached to a pipe led down
beneath the engine, the plug of the cock being prolonged and furnished
with a pulley and weight sufficient to open the cock when released. An
arm is also fixed on the same plug or axis, and when raised is sup-
ported in that position by the trigger, which comes under or engages
therewith, as before mentioned.
The cock is shut off by the engine driver pulling a cord, which at
same time raises the arm, and the trigger being self-acting, as before
described, the cock is kept shut until the trigger is tripped by coming
into contact with the bar in the road, as before mentioned, whereupon
the arm being released the weight is allowed to fall and open the whistle,
which continues to sound until again closed by the act of the engine
driver.
A gong may be employed instead of a whistle sounded by a spring
and train, which would be released by the falling of the weighted
lever.
The device by which the lever is tripped consists of a small bar or
lever I mounted on a horizontal axis G supported in suitable bearings
bolted upon a sleeper at the middle of the track and at a suitable
distance in advance of the ordinary distant signal. The lever I is
weighted at H, so as to assume an upright position when released. The
device is worked by a continuation I¹ of the wire working the distant
signal (or it may have an independent wire) and is so arranged that
when the distant signal stands at danger this bar will stand erect in
such a position as to trip the tripper on any locomotive passing over it

page_text: and sound the whistle or gong, as described. When the distant signal
is pulled off and stands at "line clear" the lever I is pulled out of the
way
of the trigger.
.
Having described the nature of the Invention, and the manner of
performing the same, we declare that what we claim as the Invention
to be protected by the herein-before in part recited Letters Patent is the
mechanism consisting of a weighted lever C and the trigger or pendulous
rod E combined and applied to a locomotive engine, and operated sub-
stantially as and for the purpose described.
In witness whereof, I, the said Edward Jacob Hill, for myself 1
and on behalf of the said Josiah Latimer Clark, have hereunto
set my hand and seal, this Thirteenth day of August, in the
year of our Lord One thousand eight hundred and seventy-
four.