IMPROVEMENTS IN SELF-ACTING SIGNAL APPARATUS FOR PREVENTING COLLISIONS ON RAILWAYS
Year: 1869

page_text: LETTERS PATENT to John Smith, of No. 2, Stanley Terrace, Rathgar,
in the County of Dublin, Timber Merchant, for the Invention
of "IMPROVEMENTS IN SELF-ACTING SIGNAL APPARATUS FOR PREVENTING
COLLISIONS ON RAILWAYS."
Sealed the 22nd October 1869, and dated the 26th April 1869.
PROVISIONAL SPECIFICATION left by the said John Smith at the
Office of the Commissioners of Patents, with his Petition, on the
26th April 1869.
I, JOHN SMITH, of No. 2, Stanley Terrace, Rathgar, in the County
of Dublin, Timber Merchant, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN SELF-ACTING SIGNAL APPARATUS FOR
PREVENTING COLLISIONS ON FAILWAYS," to be as follows:-
This Invention relates to certain improvements in self-acting signal
apparatus for indicating the approach of two trains within a given
distance from each other on the same line of rails whereby accidents
resulting from collisions will be avoided; and consists, according to one
method, in so arranging and working a line of railway signals that at
the passage of any train past some or any of such signals certain of

page_text: them, both in front and rear of the said train, will by the action of the
passing train itself be set to danger.
One of various modes by which this may be accomplished consists in
having semaphores or other signal apparatus erected at convenient
distances along the line, the signals in connection with such semaphores
being acted on by gravity or otherwise, so that in the absence of any
preventive arrangement all the signals on the left side of the semaphores
would indicate danger and all the signals on the right would indicate
safety. Attached to such semaphores are detents, which will prevent
the signals from assuming their above-mentioned natural position
and by which the reverse position may be indicated. Thus when the
signals at the left side are caught by such detents safety will be
indicated, and when the signals at the right side are so caught danger
will be indicated. These detents are acted upon by springs or otherwise
so as to insure the signals being caught by them when by the action of
any suitable mechanical force they are brought to the latter mentioned
positions. Levers, wheels, or other convenient mechanical arrangements
are so disposed that at the passage of a train past any one of the above-
mentioned semaphores the motion or force of such train in passing will
cause the signals to assume the latter mentioned positions, where they
would be retained by the action of the detents above referred to.
Attached to the semaphores are electro-magnets acting by means of
their armatures on the detents, so that when currents of electricity are
conveyed by means of a battery through the magnets on the passage
of a train these detents may be withdrawn, and the signals be allowed
to resume the positions which the forces acting on them would cause
them to do. The connections between the battery and the coils of the
several electro-magnets are so arranged that as each train passes a
semaphore it will establish an electric communication with the magnets
acting on signals at the opposite sides of each alternate semaphore in
the front and rear of the train, causing a danger signal to be shewn
in front at the second semaphore in advance, and at the rear of the
semaphore which the train is in the act of passing, whilst at the same
time it restores the other signal on that semaphore which had been
previously set to danger to a position indicating safety, and also brings
the danger signal on the second semaphore in the rear to safety, thereby
restoring both the signals on the rear semaphore to their normal
condition of safety. By adopting a similar arrangement of certain con-

page_text: nections to be actuated by a train moving the opposite direction no
two trains need be brought within a given distance from each other
without such approach being indicated to persons in charge of the
trains.
According to another arrangement it is proposed to construct on any
line of railway an insulated conductor broken or interrupted in such
lengths as may seem most suitable, such conductor being connected by
means of metallic rollers or other convenient arrangement with one
of the poles of a battery attached to the train, the other pole of such
battery being connected electrically with the earth. Attached to another
train on the same line of rails are coils and magnets, so that when an
electric current is conveyed through such coils and magnets signals
may be given to any person in charge of such trains, either by the
deflection of a needle or by the attraction of such magnets on some
convenient mechanism so arranged as to give signals to either the ear
or the eye of the before-mentioned persons. One of the extremities of
the coil is connected electrically with the earth, and the other with a
roller or other convenient mechanical arrangement, whereby electrical
connection is established with the before-mentioned electric conductor.
In the event of these two trains approaching so near to each other
that the pole of the battery in the one case and the extremity of the
coil in the other are both in connection with one of the lengths into
which the before-mentioned electric conductor is divided, a current will
be conveyed through such coils and magnets, and the before-mentioned
signals will be consequently given, indicating that the two trains are
within a given distance from cach other.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Smith in the Great Seal Patent Office on
the 26th October 1869.
0 TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
SMITH, of No. 2, Stanley Terrace, Rathgar, in the County of Dublin,
Timber Merchant, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-sixth day of April, in the year

page_text: of our Lord One thousand eight hundred and sixty-nine, in the thirty-
first year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said John Smith, Her special license
that I, the said John Smith, my executors, administrators, and
assigns, or such others as I, the said John Smith, 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 "IMPROVEMENTS IN
SELF-ACTING SIGNAL APPARATUS FOR PREVENTING COLLISIONS ON RAILWAYS," upon
the condition (amongst others) that I, the said John Smith, my executors
or administrators, 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 Smith, 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 accompanying
Drawings, and to the letters and figures marked thereon, that is to
say:
My said Invention relates to certain improvements in self-acting signal
apparatus for indicating the approach of two trains within a given
distance from each other on the same line of rails whereby accidents
resulting from collisions will be avoided.
According to my Invention I propose to construct on any line of
railway an insulated conductor broken or interrupted in such lengths
as may seem most suitable, such conductor being connected by means
of metallic rollers or other convenient arrangement with one of the poles
of a battery attached to the train, the other pole of such battery being
connected electrically with the earth. Attached to another train on the
same line of rails are coils and magnets, so that when an electric current
is conveyed through such coils and magnets signals may be given to
any persons in charge of such trains, either by the deflection of a needle

page_text: or by the attraction of such magnets on some convenient mechanism
so arranged as to give signals to either the car or eye of the before-
mentioned persons. One of the extremities of the coil is connected elec-
trically with the earth and the other with a roller or other convenient.
mechanical arrangement, whereby electrical connection is established with
the before-mentioned electric conductor. In the event of these two trains
approaching so near to each other that the pole of the battery in the
one case and the extremity of the coils in the other are both in con-
nection with one of the lengths into which the before-mentioned electric
conductor is divided, a current will be conveyed through such coils and
magnets and the before mentioned signals will be consequently given,
indicating that the two trains are within a given distance from each
other.
And in order that my said Invention may be fully understood, I
shall now proceed more particularly to describe the same, and for that
purpose shall refer to the explanatory Sheet of Drawings hereunto.
annexed.
A, A', represent two trains approaching each other on the same line
of rails. Along such line of rails a number of insulated metallic con-
ductors B, B, B, C, C, C, are crected, and each alternate conductor is
connected by an ordinary insulated wire b and c, so as to constitute two
distinct sets of conductors throughout any convenient distance (say, for
example, about double of that a nearer approach than which it is desired
to prevent). All these conductors B, B, B, C, C, C, along the railway
are connected in "blocks" of this given length, each "block" however
being entirely disconnected with the others. The "blocks" of each
set are so arranged that the commencement and termination of each
"block" of the one set will be situate about the centre of a corrc-
sponding "block" of the other set, and vice versa. Attached to each
train are metallic rollers D, D, and E, and D¹, D', and E', which
rollers are so arranged as to run in contact with the before-mentioned
conductors, such contact being insured either by gravity or by the
pressure of a spring. The rollers D, D, and D', D', are insulated from
the parts of the trains and from the earth, whilst the rollers E, E¹, are
electrically connected with the wheels and, as will be herein-after men-
tioned, with the rails or earth. These rollers should be so fixed that
when the rollers D, D, are in contact with conductors of one set it shall

page_text: be impossible for the roller E of the same train to be in contact with a
conductor of the same set, the rollers D', D', and E being arranged in
like manner. Attached to each train there is an electric battery F and F¹;
one of the poles of each battery is connected by an insulated wire with
an electric alarum R and R', such insulated wire being continued and
connected electrically with the rollers D, D, or D', D', in the case of the
train A'. The opposite pole of each battery is to be connected with the
wheels and by them with the rails. The rails are to be either metallically
connected with each other or electrically connected with the earth.
Now when the rollers D, D, of the train A, as shown in the Drawing, are
in contact with the conductors B, B, of one set, and the roller E' of the
train A is in contact with another of the conductors of the same set in
the same block, then a current of electricity will flow, as shown by the
red lines, from the positive pole of the battery F through the alarum R,
connected with that train and by the insulated wire to one or both of
the rollers D, D, from thence by the conductors and connecting wires b
to the roller E¹ of the approaching train, and from that through its
wheels and through the rails or earth back to the wheels of the train A,
whence it returns to the negative pole of the battery. By such current
therefore the alarum R on the train A will be sounded. The blue lines
indicate a similar current in the case of the train A', by which the alarum
connected with that train will also be sounded. By the above means it
will be evident that no two trains can approach each other within a less
distance than about half the length of the connected blocks without one
or both of the alarums being sounded, the distance between the two
approaching trains being sufficient to admit of both being brought to
a stand by the application of break power within a safe distance from
each other.
Having now described and particularly ascertained the nature of
my said Invention, and the manner in which the same is or may
be used or carried into effect, I would observe in conclusion that 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,
the system or mode of preventing collisions on railways by the employ-
ment of a series of blocks or groups of conductors disposed at given
distances along the line and connected in alternate order so as to con-
stitute two distinct sets of conductors by insulated wires in combination

page_text: with contact surfaces, and with alarums carried by the trains, the whole
being arranged and operating together substantially in the manner
herein-before described and illustrated by my Drawings.
In witness whereof, I, the said John Smith, have to this my Spe-
cification set my hand and seal, this Twenty-first day of
October One thousand eight hundred and sixty-nine.
JOHN SMITH. (L.S.)