IMPROVED APPARATUS FOR SIGNALLING ON RAILWAYS
Year: 1872

page_text: LETTERS PATENT to Robert Burn, junior, of Epsom, in the County
of Surrey, Engineer, for the Invention of "IMPROVED APPARATUS FOR
SIGNALLING ON RAILWAYS."
Sealed the 9th August 1872, and dated the 12th February 1872.
PROVISIONAL SPECIFICATION left by the said Robert Burn at the
Office of the Commissioners of Patents, with his Petition, on the
12th February 1872.
I, ROBERT BURN, junior, of Epsom, in the County of Surrey, Engineer,
do hereby declare the nature of the said Invention for "IMPROVED
APPARATUS FOR SIGNALLING ON RAILWAYS," to be as follows:-
This Invention consists in certain arrangements by means of which
the ordinary system of railway signals is rendered certain, secure, and
intelligible in operation, whether by day or night, and during the
existence of fog, whilst the necessity for the use of detonating signals is
obviated.

page_text: A crank is attached to the ordinary signal post and connected with
the lever balance employed therewith, and by means of this crank
motion is imparted to a sliding or adjustable bar which is placed at right
angles to the rails, and is protruded and withdrawn according as the
signal arm is raised or lowered. The lower end of the bar is so arranged
that when the signal is at “ danger" it is thrust forward into close
proximity with the rail, and when the signal arm is depressed to
"caution" the bar is drawn back so as to be clear of the signalling
arrangements on the engine, which are constructed as follows:-On the
railway or other convenient part of the engine is fixed a double-action
trigger, which is equally available in whatever direction the engine may
be travelling. The trigger actuates a hammer or hammers (fitted with
lever escapements or other similar or analogous contrivances) by which
a gong or other suitable signal is struck or acted upon, and whereby the
engine driver is informed that the sliding bar is protruded and the signal
danger." When the sliding or adjustable bar is withdrawn
on the signal arm being placed at "caution" the engine will pass
unchallenged.
arm at "
By means of simple adaptations, which will be well understood by
persons conversant with such mechanism, the apparatus herein-before
described can be applied to signal posts placed on the top of an embank-
ment or in other exceptional positions; and in tunnels the sliding or
adjustable bar can also be readily connected with the existing signals.
The mechanism herein-before described can if desired be so arranged
as to act in advance of the signal post.
It should be observed that the trigger and gong, or other signal affixed
to the engine, are equally available for protection in case of a train
breaking down, and in the event of the permanent way being under
repair, or of other works being in progress which may render it desirable
that the attention of the engine driver should be aroused. This is
effected by means of a small screw clip which can readily be fixed on
the rail, and which is so arranged that it will come in contact with the
trigger on the engine, and cause the gong or other signal to be acted
upon.
It is manifest that the arrangements herein-before described may be
applied so as to give the signals in each guard's van or at any desired
part of the train as well as on the engine.

page_text: In order to prevent an engine driver becoming indifferent to the
warning of the signal an adjusting lever is arranged so as in clear
weather to raise the trigger perpendicularly sufficiently to escape contact
with the sliding or adjustable bar, but not so high as to admit of its
passing the danger clip before referred to without striking, the contac
point of the one being somewhat higher than that of the other, but not
so much as to impede the action of the trigger when lowered in case of
fog.
In cases in which it is preferred instead of leaving the control of the
fog signal in the hands of the engine driver to place it in those of the
signalman the trigger is not made adjustable, but the sliding or adjust-
able bar instead of being connected with the existing lever balance has
an independent movement, and is connected with the signal box by a
separate wire and a separate series of pulleys, and in fine weather is not
attached to the signal lever, but in foggy or stormy weather is readily
attached by means of a coupling or § hook, and is then worked as before
described simultaneously with the ordinary signals. The action may
also be controlled by requiring the lever to make a longer range to put
the sliding or adjustable bar in action than to put the signal arm at
"danger."
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Robert Burn in the Great Seal Patent Office on
the 12th August 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
BURN, junior, of Epsom, in the County of Surrey, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twelfth day of February, in the year of
our Lord One thousand eight hundred and seventy-two, in the thirty-
fifth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Robert Burn, Her special licence that
I, the said Robert Burn, my executors, administrators, and assigns,
or such others as I, the said Robert Burn, my executors, administrators,
and assigns, should at any time agree with, and no others, from

page_text: 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 "IMPROVED APPARATUS FOR
SIGNALLING ON RAILWAYS," upon the condition (amongst others) that I, the
said Robert Burn, 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 Robert Burn, 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, reference being had to the Drawings hereunto
annexed, and to the figures and letters marked thereon, that is to
say:-
-
My said Invention consists in certain arrangements by means of
which the ordinary system of railway signals is rendered certain, secure,
and intelligible in operation, whether by day or night, and during the
existence of fog, whilst the necessity for the use of detonating signals is
obviated.
A crank is attached to the ordinary signal post and connected with
the lever balance employed therewith, and by means of this crank
motion is imparted to a sliding or adjustable bar which is placed at right
angles to the rails, and is protruded and withdrawn according as the
signal arm is raised or lowered, or the crank may be dispensed with and
the sliding or adjustable bar attached in a direct manner to the signal
wire. The lower end of the bar is so arranged that when the signal is
at "danger" it is thrust forward into close proximity with the rail, and
when the signal arm is depressed to "caution" the bar is drawn back so
as to be clear of the signalling arrangements on the engine, which are
constructed as follows:-On the railing or other convenient part of the
engine is fixed a double-action trigger, which is equally available in
whatever direction the engine may be travelling. The trigger actuates
a hammer or hammers (fitted with lever escapements or other similar or
analogous contrivances) by which a gong or other suitable signal is

page_text: struck or acted upon, and whereby the engine driver is informed that
the sliding bar is protruded and the signal arm at " danger." When
the sliding or adjustable bar is withdrawn on the signal arm being
placed at "caution" the engine will pass unchallenged. The sliding or
adjustable bar may be arranged to work between guides bolted to the
fish plates.
By means of simple adaptations, which will be well understood by
persons conversant with such mechanism, the apparatus herein-before
described can be applied to signal posts placed on the top of an
embankment or in other exceptional positions; and in tunnels the
sliding or adjustable bar can also be readily connected with the existing
signals.
When desired the sliding or adjustable bar may be provided on its
under surface with a spring, so that when struck by any low-framed
truck or other rigid obstacle it is slightly depressed, the spring, however,
being too strong to allow of the sliding or adjustable bar being depressed
by the trigger.
The mechanism herein-before described can if desired be so arranged
as to act in advance of the signal post.
In some cases a balance weight or weights may be employed to assist
the action of the sliding or adjustable rod.
It should be observed that the trigger and gong, or other signal affixed
to the engine, are equally available for protection in case of a train
breaking down, and in the event of the permanent way being under
repair, or of other works being in progress which may render it desirable
that the attention of the engine driver should be aroused. This is
effected by means of a small clip which can readily be fixed on the rail,
and which is so arranged that it will come in contact with the trigger
on the engine, and cause the gong or other signal to be acted upon.
It is manifest that the arrangements herein-before described may be
applied so as to give the signals in each guard's van, or at any desired
part of the train, as well as on the engine.
In order to prevent an engine driver becoming indifferent to the
warning of the signal an adjusting lever is arranged so as in clear
weather to raise the trigger perpendicularly sufficiently to escape contact
with the sliding or adjustable bar, but not so high as to admit of its

page_text: passing the danger clip, before referred to, without striking, the contact
point of the one being somewhat higher than that of the other, but not
so much so as to impede the action of the trigger when lowered in case
of fog.
In cases in which it is preferred instead of leaving the control of the
fog signal in the hands of the engine driver to place it in those of the
signalman the trigger is not made adjustable, but the sliding or adjust-
able bar instead of being connected with the existing lever balance has
an independent movement, and is connected with the signal box by a
separate wire and a separate series of pulleys, and in fine weather is not
attached to the signal lever, but in foggy or stormy weather is readily
attached by means of a coupling or S hook, and is then worked as before
described simultaneously with the ordinary signals. The action may
also be controlled by requiring the lever to make a longer range to put
the sliding or adjustable bar in action than to put the signal arm at
"danger."
I will now proceed to refer to the accompanying Drawings, from which
the nature of my said Invention will be more clearly understood.
Figure 1 is an elevation of the signalling apparatus with the signal
arm at the danger point and the sliding or adjustable bar thrust forward
into position for actuating the trigger on the engine; Figure 2 being
the same view but with the arm at "caution," and the sliding or adjust-
able bar drawn back; Figure 3 being a plan of the sliding or adjustable
bar. The same letters of reference refer to like parts in these Figures.
A is the sliding or adjustable bar; B, the trigger on the engine; C, the
gong arrangement; D, balance weight for assisting the action of the
sliding or adjustable bar; E, the crank which connects the sliding or
adjustable bar to the balance lever of the signal post.
Figure 4 is an enlarged view of the trigger B and gong arrangement C.
Figures 5, 6, and 7 shew respectively side view, plan, and back view
of the arrangement of the sliding bar when used in advance of the signal
post.
In these Figures A is the sliding or adjustable bar; B, B, b, b, are the
cranks and rods or wires which connect the same with the balance lever
of the sional nost

page_text: Figures 8, 9, and 10 shew respectively side view, plan, and end view
of the danger clip, A being the bar or rod with which the trigger comes
in contact.
Having thus described and ascertained the nature of my said Invention,
and in what manner the same is to be performed, I would observe in
conclusion that what I consider novel and original, and therefore claim
as constituting the Invention secured to me by the said herein-before in
part recited Letters Patent are,-
First. The combination and arrangement of parts and mechanism in
connection with the ordinary signalling apparatus, substantially as and
for the purposes herein-before described and set forth.
And secondly. The arrangement and use of the danger clip] herein-
before mentioned, substantially as and for the purposes herein described
and set forth.
In witness whereof, I, the said Robert Burn, have hereunto set
my hand and seal, this Twelfth day of August, in the year of our
Lord One thousand eight hundred and seventy-two.
Witness,
R. S. MORDAUNT VAUGHAN,
54, Chancery Lane.
ROBERT BURN, JUN. (L.S.)