IMPROVEMENTS IN APPARATUS FOR WORKING RAILWAY SIGNALS
Year: 1873

page_text: LETTERS PATENT to Charles Henry Twynam, of 4, Victoria Strect,
in the City of Westminster, Gentleman, for the Invention of
"IMPROVEMENTS IN APPARATUS FOR WORKING RAILWAY SIGNALS."
Scaled the 22nd July 1873, and dated the 24th January 1873.
PROVISIONAL SPECIFICATION left by the said Charles Henry Twynam
at the Office of the Commissioners of Patents, with his Petition,
on the 24th January 1873.
I, CHARLES HENRY TWYNAM, of 4, Victoria Street, in the City of
Westminster, Gentleman, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN APPARATUS FOR WORKING RAILWAY SIGNALS,"
to be as follows:-
The object of my Invention is to enable a semaphore or other railway
signal to be moved to the danger position by the passing train. For
this purpose I employ at any suitable position between the station and
the signal a wheel, around which is passed a chain or cord which leads

page_text: from the station to the signal in the usual manner. At the signal end
this chain or cord is attached to the ordinary weighted lever for working
the signal, so that when the said chain or cord is pulled upon at the
station end the signal is moved to the caution or all clear position, as is
well understood. When the chain or cord is thus pulled the wheel
above mentioned rotates upon its axis. On the same axis as or formed
in a piece with this wheel is a ratchet wheel into which a weighted paul
or catch takes, so as to prevent the wheels returning after having been
rotated as above explained. To this paul or catch one end of a lever is
attached, while the other end of the lever carries a curved piece or arm
so placed as to bo acted upon by the flange of the wheels or other part of
the train.
The action is as follows:-The signal having been placed at the caution
or all clear position where it is retained by means of the pawl or catch
above described, the passing train acts upon the arm above mentioned,
and thus by the intermediation of the lever releases the paul or catch
from the ratchet wheel, so that the ordinary weight which is connected
with the signal is free to act and to move the signal to danger. The
signal may be afterwards returned to caution or all clear by the
attendant at the station pulling the chain or cord. To enable the a
attendant to move the signal to danger at any time I lead a chain or
cord from the paul or catch to the station to enable him to release the
paul or catch from the wheel.
In some cases instead of the ratchet wheel and paul or catch, I
employ a plain wheel or disc having a holo in its face to receive the end
of a rod, which is caused by a weight to enter the said hole when the
wheel is rotated by the chain or cord, and to be withdrawn from the
hole by the passing train, and thus release the wheel.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Charles Henry Twynam, in the Great Seal Patent 30
Office on the 24th July 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
HENRY TWYNAMм, of 4, Victoria Street, in the City of Westminster,
Gentleman, send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-fourth day of January, in the
year of our Lord One thousand cight hundred and seventy-three, in the
thirty-sixth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Charles Hcury Twynam, Her special
licence that I, the said Charles Henry Twynam, my executors, adminis-
trators, and assigns, or such others as I, the said Charles Henry
Twynam, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times there-
after during the term therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ircland, the Channel Islands, and Isle of Man, an Inven-
tion for "IMPROVEMENTS IN APPARATUS FOR WORKING RAILWAY SIGNALS," upon
the condition (amongst others) that I, the said Charles Henry Twynam,
my exccutors or administrators, by an instrument in writing under my,
or their, or one of their hands and scals, 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 imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Charles Henry Twynam, 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 thereof, reference being had to the
accompanying Drawings, that is to say :—
The object of my Invention is to enable a semaphore or other railway
signal to be moved to the danger position by the passing train. For
this purpose I interpose a wheel at any suitable position between the
station and the signal, and at this position I divide the ordinary wire
which leads from the station to the signal, and I connect the two cuds
of the divided wire to the said wheel by means of short lengths of chain.
When the wiro is pulled upon in the usual manner the signal is moved to
the "caution
" or all clear" position as will be well understood, and
the wheel is at the same time rotated on its axis. The said wheel has
in its face near the periphery a hole to receive the end of a rod, which is
caused by a weight to enter the said hole when the wheel is rotated as
above-mentioned, and thus to prevent the wheel returning. The
opposite end of this rod is jointed to an arm so placed as to be acted

page_text: upon by the flange of the wheels or other part of a passing train
whereby the rod is withdrawn from the hole in the wheel and the wheel
released. The ordinary weight which is connected with the signal is
then free to act and to move the signal to danger.
My Invention will bo fully understood on reference to the accom- |
panying Drawings, Figure 1 being a side clevation; Figure 2 a plan;
and Figure 3 a view on a larger scale taken transversely to the rails;
Figure 4 is a face view of the wheel detached.
A is the signal post carrying a semaphore B which is mounted on an
axle O;
D is a rod leading from the axle C to a lever E, to one end of
which lever a weight F is attached, while to its other end is connected
one end of a chain G. This chain after passing round the pulley H
is connected to the ordinary wire, which in its turn is connected to
another short chain G' attached to a double grooved wheel I. From the
wheel I another chain K leads to the other part of the ordinary wire
which has been divided for this purpose as above explained, and is itself
attached in the usual way to the signal lever L. M is a rod, one end of
which when the signal is at "caution" or "all clear" takes into a hole N
in the face of the wheel I, while its other end passes through a hole in
the rail and is jointed to an arm or lever O. This arm is centred at P
and carries a weight Q.
ΟΙ
"all
The action is as follows:-To place the signal at "caution" or "all clear"
the signalman draws back the lever L so as to pull the chain K and
thereby cause the wheel I to rotate on its axis until the hole N in the
wheel comes opposite the end of the rod M which is guided to the hole
by a groove R in the wheel. The weight Q then causes the end of the
rod to enter the hole so that the wheel is prevented returning. The
revolution of the wheel I has simultaneously produced a pull upon the
chain G and thereby moved the semaphore B to the "caution
clear" position, at which it will remain so long as the end of the
rod M remains in the hole N. The chain K must now be slacked. On tho
passing of a train the ſlange of the wheels comes between the rail and
the arm O, forces this arm away from the rail, and thus withdraws the
rod M from the hole N. The wheel I being therefore released the
weight F is enabled to move the signal B to "danger" in which position it
will remain until returned to "caution or "all clear" by the signalman
pulling back the lever L. To enable the signal to be moved to "danger”
"3