IMPROVE- MENTS IN RAILWAY SIGNALS
Year: 1858

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields,
in the County of Middlesex, and of 166, Buchanan Street, in the City of
Glasgow, North Britain, Gentleman, for the Invention of "IMPROVE-
MENTS IN RAILWAY SIGNALS."-A communication from Jean Joseph Etienne
the Empire of France.
Sealed the 20th August 1858, and dated the 5th March 1858.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at
the Office of the Commissioners of Patents, with his Petition, on the
5th March 1858.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, and of 166, Buchanan Street, in the City of Glasgow, North
Britain, Gentleman, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN RAILWAY SIGNALS," a communication from Jean Joseph
Etienne Lenoir, of Paris, in the Empire of France, to be as follows:-
This Invention relates to a peculiar construction, arrangement, and mode
of working signals placed at suitable intervals along railways, whereby the
passage of a train is instantly indicated by the corresponding signal, which
signal continues to shew "caution" or "danger" until the next signal has
been passed, thus enabling a determined distance to be observed between each
train, by which means all collisions may be avoided.

page_text: The signal proposed to be used, although various modifications thereof may
be made, consists of a metallic or other disc placed on a signal post at the
side of the line, and having an aperture in the centre, which aperture is
covered by a colored glass to indicate "caution" or "danger," or is left un-
covered when the line is "all clear." The colored glass is carried at the lower
end of a hanging lever, and is counterbalanced by a weight at the upper end
of the lever. This lever is connected to a second lever working on a centre
at its lowest extremity, so that on a lateral motion in either direction being
given to the second lever, the glass will be brought in front of or removed
from the aperture in the disc. This movement of the second lever is effected
by electro-magnets placed on either side of it, the wires of one pair being
connected to the rail, and those of the other pair to a metal bar not in con-
tact with the rail, but in a convenient position to be acted upon by an
insulated blade spring, or flexible metallic bar, carried by one of the carriages
of the passing train. This carriage is furnished with a battery, one pole of
which is conducted through the axle and wheels to the rail, whilst the other
pole is connected with the insulated blade spring. It follows that on the
passage of a train the contact of the blade spring with the metal bar at the
side of the line will establish the circuit, and cause one pair of magnets to
draw the second lever to one side, so as to bring the glass in front of the
aperture of the disc, whilst at the same time the current passing along the
rail to the last signal passed will bring into action the opposite-pair of magnets
of that signal, and will remove the glass, shewing to the next coming train that
the previous train has passed the preceding signal, and that there is no danger
of collision. Should a break down occur between two signal posts, the signal
last past will remain up to indicate "caution" or "danger" to the next
train.
At night a lamp may be substituted for the colored glass. Where great
distances are required between the signals, an additional battery working in
connection with the battery of the train may be used situated at the foot of
the signal post.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Henry Johnson in the Great Seal Patent Office on
the 4th September 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN 35
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the, County of Middlesex,

page_text: and of 166, Buchanan Street, in the City of Glasgow, North Britain, Gentle-
man, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifth day of March; in the year of our Lord One
thousand eight hundred and fifty-eight, in the twenty-first year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
John Henry Johnson, Her special license that I, the said John Henry
Johnson, my executors, administrators, and assigns, or such others as I,
the said John Henry Johnson, my executors, administrators, or 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 "IM-
PROVEMENTS IN RAILWAY SIGNALS," a communication from Jean Joseph Etienne
Lenoir, of Paris, in the Empire of France, upon the condition (amongst others)
that I, the said John Henry Johnson, by an instrument in writing under my
hand and seal, 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 I, the said John Henry Johnson, 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 had to the accompanying Drawing, and
to the letters and figures marked thereon, that is to say:-
The said Invention relates to a peculiar construction, arrangement, and
mode of working signals placed at suitable intervals along railways, whereby
the passage of a train is instantly indicated by a signal, which signal continues
to show "caution" or "danger" until the next signal has been passed by the
train, thus enabling a determined distance to be observed between each train,
by which means all collisions may be avoided.
The signal proposed to be used (although various modifications thereof may
be employed) consists of a metallic or other disc placed on a signal post at the
side of the line, and having an aperture in the centre, which aperture is
covered by a colored glass to indicate "caution" or "danger," or is left
uncovered when the line is "all clear." The colored glass is carried at the
lower end of a hanging lever, and is counterbalanced by a weight at the
upper end of the lever. This lever is connected to a second lever working on
a-centre at its lower extremity, so that on a lateral motion in either direction

page_text: being given to the second lever, the glass will be brought in front of o
removed from the aperture in the disc. This movement of the second leve
is effected by a pair of electro-magnets placed on each side of it, the wires of
one pair being connected to the rail, and those of the other pair to a metal
bar not in contact with the rail, but in a convenient position to be acted upon
by an insulated blade spring, or flexible metallic bar, carried by one of the
carriages of the passing train. This carriage is furnished with a battery, one
pole of which communicates through the axle and wheels with the rail, whilst
the other pole is in communication with the insulated blade spring. It
follows that on the passage of a train, the contact of the blade spring with
the metal bar at the side of the line will establish the circuit, and cause one
pair of magnets to draw the second lever to one side (so as to bring the glass
in front of the aperture in the disc, whilst at the same time the current
passing along the rail to the back signal last passed will bring into action
the opposite pair of magnets of that signal, and will remove the glass, showing
to the next coming train that the previous train has passed the preceding
signal, and that there is no danger of collision. Should a break down occur
between two signal posts, the signal last passed will continue to indicate
"caution
25
or danger to the next train. At night a lamp may be sub-
stituted for the colored glass. Where great distances are required between
the signals an additional battery may be employed working in connection with
the battery of the train, and situate at the foot of the signal post.
"
And in order that the said Invention may be fully understood I shall now
proceed more particularly to describe the same, and for that purpose I shall
refer to the Figure on the Sheet of Drawings hereunto annexed.
The accompanying Drawing represents a side elevation of one of my self-
acting disc signals in complete working order, and indicating the line to be
"all clear," the central aperture being uncovered. B is the disc, mounted on
an upright A, and having its centre perforated by a circular opening of about
eighteen inches diameter. In front of this disc is arranged a lever H working
on a centre at a below, and having near its lower end a double metallic plate
I, I, which communicates with one or other of the electro-magnets J, K,
arranged on either side of the lever H. The upper extremity of this lever
gives motion to a second lever having a counterbalance C attached to its
upper end, and working on a centre at b. This lever has a coloured glass D
fastened to it of dimensions corresponding to the circular opening in the dise
B. The lever H is so curved as not to interfere with the outline of the
opening in the disc.
A battery carried in the train communicates by one of its poles with an

page_text: insulated blade spring L made of some metal of good conducting power, and
of a suitable strength, in order to retain its convex form towards the bottom,
with the assistance of the supports c, c, to which the ends are attached. The
axle, wheel, and rail serve to conduct the other pole.
If the wire of one of the coils J, K, be placed in direct communication
with the metallic rod M, and the carriage with its spring L in passing along
causes the latter to come in contact with the rod M, as is shewn in the
Drawing, the circuit will then be complete, and the electric current cir-
culating through the coils of the magnets will immediately attract the plates
I, and will consequently communicate motion to the lever H, and the lever
which carries the glass D, thereby either covering or otherwise the circular
opening of the disc B according as the electric current acts on the coils J or
K. Thus, by having the glass D of some brilliant colour, such as red or
green, it will be readily perceived some distance off after the passage of a
train.
The coil wire of the magnets J which has moved the glass D into a
vertical position, namely, in front of the disc B, is prolonged, and joins the
coil of the magnets K of the next back signal, which is fitted with similar
apparatus, and stationed about two thousand or three thousand yards apart,
and so on for the whole length of the line. As the magnets K produce just
the contrary effect of the magnets J, it follows that at the moment that the
danger signal bas warned a too closely approaching train to slacken its speed,
this same colour will be removed from in front of the disc immediately in the
rear, thereby signalling that the line is clear ahead as far as the next forward
signal.
This Invention may be carried out in various ways without affecting the
principle therein contained. For example, in lieu of the colored glass or
illuminated lantern any other kind of signal may be substituted.
I do not confine myself to the use of any fixed number of electric coils, but
propose to employ as many as I may judge convenient for attaining the
desired end effectively.
Having now described and particularly ascertained the nature of the said
Invention, and the manner in which the same is or may be used or carried
into effect, I would observe in conclusion that I do not confine or restrict
myself to the precise details or arrangements which I have had occasion
to describe or refer to, as variations may be made therefrom without
deviating from the principles or main features of the said Invention; but what
I consider to be novel and original, and therefore claim as the Invention
secured to me by the herein-before in part recited Letters Patent is,

page_text: First, the general construction, arrangement, and mode of working railway
signals, as berein-before described.
Second, the application and use of an electric current for working signals
on railways by the passage of the train, in the manner and for the purpose
herein-before described.
Third, the application and use of two combined electric batteries in such
a manner that one shall complete the circuit of the other, as herein-before
described.
In witness whereof, I, the said John Henry Johnson, have hereunto set
my hand and seal, this Third day of September, One thousand eight
hundred and fifty-eight.
J. HENRY JOHNSON. (L.S.)