IMPROVEMENTS IN RAILWAY SIGNALLING APPARATUS
Year: 1875

page_text: PROVISIONAL SPECIFICATION left by Louis Knoblauch at the Office
of the Commissioners of Patents, with his Petition, on the 27th
April 1875.-A communication from abroad by Eduard Zimmer-
mann and Rudolph Knoblauch, of Cologne and Duisburg.
I, LOUIS KNOBLAUCH, of 60, King William Street, in the City of
London, Merchant, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN RAILWAY SIGNALLING APPARATUS," a communication
to me from abroad by Eduard Zimmermann and Rudolph Knoblauch,
of Cologne and Duisburg, to be as follows:-
This Invention relates to apparatus for signalling on railways, and
has for its object compensating for the contraction and expansion of the
connecting wires under the influences of variations in the temperature of
the atmosphere or due to any other cause. In order to effect this object
it is proposed to employ a large bell-crank lever, onc arm of which is
weighted and occupies a nearly horizontal position, whilst the other arm
which is bent to an S or rounded shape terminates in a vertical extremity
situate nearly beneath or in a vertical line with the fulcrum, and has
attached to it the conducting wire leading to the signalman's lever for
regulating the signals. In connection with the bell-crank lever before

page_text: mentioned there is also arranged another and smaller bell-crank lever,
one arm of which is connected to the telegraph arm or semaphore by a
wire, say, for example, in the case of arrival signals, or by a small
traction rod to the disc, say in the case of notice signals, whilst its other
arm bears against the lower arm of the lever first mentioned, which is
curved to an arc of a circle described on its axis of motion.
'
Assuming the apparatus to be in the position corresponding to the
"stop" signal of the telegraph or semaphore, and the utmost shortening
of the wire by the temperature, if the regulating lever which is connected
with the conducting wire be moved round, the lower arm of the smaller
lever will be acted upon by the curved arm of the larger lever, which
position then indicates "road clear" by continuing the motion of the
regulating lever (say even until it reaches the horizontal), the lower arm
of the smaller lever glides into the curve of the larger lever without
altering the "road clear" signal. If the stroke of the regulating lever i
at the point where the wire is attached be equal to the greatest
lengthening or shortening of the entire conducting wire to the last
telegraph or semaphore plus the space which must be traversed in order
to alter the telegraphs or semaphores from "stop" to "road clear," then
the telegraph or semaphore must necessarily always within this stroke 2
be altered from "stop" to "road clear" with the shortest possible wire
at the commencement, and with the longest wire at the end of the
sweep of the regulating lever, since in the latter case the space of the
lengthening or shortening of the wire must be traversed before the lower
arm of the smaller lever is brought into action.
A counterweight is provided as before mentioned on the upper arm of
the large lever for the purpose of maintaining the conducting wire in
constant tension in order to put back the weight of the disc round the
same to "stop."