IMPROVED SELF-ACTING APPARATUS FOR PLACING FOG SIGNALS UPON RAILWAYS
Year: 1869

page_text: PROVISIONAL SPECIFICATION left by John Norris and Edwin Long-
worth at the Office of the Commissioners of Patents, with their
Petition, on the 24th November 1869.
We, Jonx NORRIS, of Manchester, and EDWIN LONGWORTH, of Wine-
wall, near Colne, both in the County of Lancaster, do hereby declare
the nature of the said Invention for "IMPROVED SELF-ACTING APPARATUS
FOR PLACING FOG SIGNALS UPON RAILWAYS," to be as follows:-
This Invention relates to an improved self-acting apparatus whereby
the engine of a train in passing along the rails actuates a simple arrange-
ment of mechanism which places a fog signal on the metals a certain
distance behind the train, and holds it there till the engine has passed on
a certain given distance again, and then places another and removes the
first, and so on, so that the engine always leaves a fog signal a certain
distance behind it throughout the whole journey, which said signal
remains there any length of time till the engine has gone on a certain
distance again, and no other engine or train can come within a certain
distance of the rear of the first, whether travelling or stationary, without
being warned by the explosion of the fog signal.
The apparatus which we propose to employ for this purpose consists of
a small trigger or lever placed just inside the rail and fixed on one end
of a short shaft or spindle which passes under the rail and has a toothed

page_text: quadrant attached to its other end. When the wheel of an engine
passes over it depresses the trigger or lever, and with it the quadrant,
a catch at one end of a weighted lever falling into the teeth of the
quadrant and holding it in that position till released. To the quadrant is
attached one end of a wire or chain, the other end of which is connected
to one arm of a bell-crank lever mounted on a stud close to the rail at
about two hundred yards (or other convenient distance) from the trigger
or lever. The other end of the bell-crank lever carries a fog signal, and
this lever is so arranged that when an engine depresses the lever or
trigger it pulls the bell crank and places the fog signal on the rail two
hundred yards behind it, the catch and quadrant hold it in that position
till the engine has advanced (say) another two hundred yards, when the
wheel comes against another trigger and places another fog signal on
the rails two hundred yards behind its advanced position by a repitition
of the same mechanism, and the second bell crank being connected by
a wire with the catch of the first quadrant releases the latter and allows
a weighted lever to withdraw the first fog signal, and thus the engine.
is constantly laying down fog signals on the rail behind it, and taking
them off again as soon as it has advanced say, four hundred yards, but
if the engine should stop either by accident or otherwise before it has
reached the four hundred yards the fog signal remains on the rail until
the engine goes on again.
It is intended that each engine or train should be provided with fog
signals, and that upon any engine exploding a signal it should be the
duty of the person in charge to bring the engine or train to a standstill
and replace the exploded signal by a fresh one, and upon no account to
advance till by the movement of the bell crank he is convinced that the
engine ahead has gone on again.
We have mentioned two hundred yards for the sake of illustration as
the distance apart of the apparatus, but it will of course be evident that
any shorter or longer distance may be adopted, according as the
exigencies of each particular case may require, shorter distances being
preferable on sharp curves, and much longer distances being sufficient on
straight level parts of the line.