IMPROVED SELF-ACTING RAILWAY SIGNAL Apparatus
Year: 1873

page_text: LETTERS PATENT to Robert Smellie, of Portobello, and John Vance,
of Edinburgh, in the County of Mid Lothian, North Britain, for the
PROVISIONAL SPECIFICATION left by the said Robert Smellie and
John Vance at the Office of the Commissioners of Patents, with
their Petition, on the 1st April 1873.
We, ROBERT SMELLIE, of Portobello, and. JOHN. VANCE, of Edinburgh,
in the County of Mid Lothian, North Britain, do hereby declare the
nature of the said Invention of "IMPROVED SELF-ACTING RAILWAY SIGNAL
Apparatus,” to be as follows; that is to say:-
This Invention, which relates to an improved self-acting apparatus
for actuating signals on railways, is applicable for working either
mechanically operated or electrically operated signals:

page_text: The apparatus consists of "stops," which move vertically, or hori-
zontally, or at an angle, being attached to levers, and connected together
by a chain rope or its equivalent. These "stops" are situated at the
side of the rails, and are held on or in guides, so that the wheels of an
engine or train passing over the rails depress or move one of the "stops,"
which through the levers and chain or rope connection elevates the "stop"
at the other end of the system or apparatus. By this means, that is to
say, by the motion of the apparatus thus produced, the link work whereby.
a signal is actuated is moved so as to raise a signal at any required point
on the line of railway, thereby indicating the approach of a train, and so
producing a "block" of any required portion of the line until the
"stop" at the further end of the apparatus is reached, which being
depressed or moved by the wheels of the passing engine or train, operates
the apparatus in the reverse direction and lowers the signal, thereby
shewing the line to be clear, also putting the "stop" first mentioned
into position to be operated in the manner described by the next engine
or train proceeding on the line of rails.
I
SPECIFICATION filed in pursuance of the conditions of the Letters
Patent, and of an Order of the Lord Chancellor, by the said Robert
Smellie and John Vance in the Great Seal Patent Office on the
10th October 1873..
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, ROBERT 2
SMELLIE, of Portobello, and JOHN VANCE, of Edinburgh, in the County
of Mid Lothian, North Britain, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the First day of April, in the year of our Lord
One thousand eight. hundred and seventy-three, in the 36th year of Her 3
reign, did, for Herself, Her heirs and successors, give and grant unto
us, the said Robert Smellie and John Vance, Her special license. that,

page_text: being depressed or moved by the wheels of the passing engine or train,
operates the apparatus in the reverse direction and lowers the signal,
thereby shewing the line to be clear, also putting the "stop" first men-
tioned into position to be operated in the manner described by the next
engine or train proceeding on the line of rails.
i
:
It is obvious that in case of electrically operated signals the appa-
ratus herein-before described is adapted for making or breaking the
electrical circuit, and thereby operating the signals.
And in order that our said Invention may be properly understood, we
now proceed more particularly to set forth the system, mode, or manner
in or under which the same is or may be used or practically carried into
effect, that is to say:—
On the Sheet 1 of Drawings hereunto appended Figure 1 is a side
elevation of the improved-self-acting railway signal apparatus; Figure 2
is a plan thereof; and Figure 3 a transverse section of the same on the
line a, a, Figure 1.
".
As shewn by these Figures curved or other suitably formed "stops" A
and A¹ respectively are situated at the inner side of and near to one of
the rails B of the railway. The stops A and A¹ are attached by means
of hinged joints or their equivalent to the short arms of levers C, the
long arms of the levers C being connected to chains, ropes, or their
équivalent D and E respectively, by means of which the semaphore or
signal arm is actuated, as herein-after more particularly described. The
stops A and A¹ are by preference arranged level with or slightly below
the level of the rails B, so that the flanches on the wheels of an engine or
train passing over the rails B act on and depress the stops" A and A¹,
thereby elevating the long arms of the levers C. The semaphore or
signal arm F is attached to a pulley G, carried on an axis supported by
the signal post H. The chain or rope D on being connected to the long
arm of the lever C is passed round guide pullies I, and upwards over the
pulley G, and from thence downwards, passing round a guide pulley J,
and is finally attached to a weight K, which is provided with studs e,
situated in guides L formed on or attached to the signal post H. The
chain or rope E, after being attached to the long arm of the other
lever C, is passed round and over guide pullies M, and is finally attached

page_text: to the periphery of a pulley N fixed to and supported on a shaft b. The
shaft 6 is also provided with arms C, or their equivalent...
When the flanch on one of the wheels of an engine or train passes
over the "stop" A, it is depressed into the position shewn on the
Drawings, thereby elevating the long arm of the lever C, pulling the
chain or rope D in the direction indicated by the arrows, and opening
out the semaphore or signal arm F into the danger position. The
weight K, which by that action has been pulled upwards in the
guides L, is caught by and rests on a ledge or shelf d, which prevents
it falling when the engine or train has passed, thereby keeping the
semaphore or signal arm F in the danger position, and so producing a
"block" of any required portion of the line until the engine or train
arrives at the second "stop" A³, which on being depressed in a similar
manner to the stop A, causes the chain or rope E to be pulled in the
direction shewn by the arrows, and partly rotates the pulley N and
arms C. The arms C by the rotating action bear against the studs e, and
thereby push them off the ledge or shelf d, thus allowing the weight K
to fall, which draws down or shuts the semaphore or signal arm F,
shewing the line clear, and allows of the "stop" A raising into the
position to be again depressed by the next engine or train passing.
Instead of the system of levers, ropes, and pullies herein-before
described, electric wires may be connected to each of the stops, and
from thence to the signal arm; and a battery being placed at each end
of the line, the wires may be kept constantly charged with electricity,
so that the flanches of the wheels when passing over the "stops" and
depressing them brings them into contact with the charged wire below,
connecting the electric current, which will thus pass direct to the
signals and operate them, and when the wheels of the train have fairly
passed the stops these will rise to their normal position, and so break the
Having now described and particularly ascertained the nature of our
said Invention, and the system, mode, or manner in or under which the
same is or may be used or practically carried into effect, we would
observe in conclusion that what we consider to be novel and original,
and therefore claim as the Invention secured to us by the herein-before
in part recited Letters Patent is, the operating of railway signals by

page_text: means of the stops".A and A¹ connected with the signal apparatus, and
actuating it in the manner substantially as herein-before described.
In witness whereof, we, the said Robert Smellie and John Vance,
have hereunto set our hands and seals, this Twenty-ninth day of
September One thousand eight hundred and seventy-three.