IMPROVEMENTS IN PNEUMATIC SIGNALLING APPARATUS FOR RAILWAY TRAINS
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by Charles Denton Abel at the Office
of the Commissioners of Patents on the 13th October 1881. A commu-
nication from abroad by Paul Rimachevsky, of Moscow, and Wassily
Tagaitschinoff, of Rjasan, both in the Russian Empire.
CHARLES DENTON ADEL, of No. 28, Southampton Buildings, Chancery Lane,
in the County of Middlesex. IMPROVEMENTS IN PNEUMATIC SIGNALLING
APPARATUS FOR RAILWAY TRAINS." [A communication from abroad by Paul
Rimachevsky, of Moscow, and Wassily Tagaitschinoff, of Rjasan, both in the
Russian Empire.]
This Invention relates to pneumatic apparatus for conveying signals to the ongino
driver or guard of a train, either automatically when a coupling breaks, or by
passengers, wherein vacuuin or partial vacuum for controlling the signalling
operations is employed, that is to say, air being exhausted continuously from a
communicating pipe or pipes in connection with apparatus acting on the signals;
theso are operated either on the rupture of the said pipe so as to admit the
atmospheric pressure, or by opening a cock, or by breaking a glass or other
diaphragm closing an inlet to the said pipe. For this purpose a pipe leading along
the train is connected at the tender or engine, firstly, to a pump for exhausting air
therefrom; and secondly, with a casing provided with diaphragms which assume
different positions according to whether partial vacuum or atmospheric pressure
exists in the said pipes, and which, by devices to be presently described, actuate a
valve in a passage leading to an audible signal, so that when the partial vacuum
in the pipes ceases to exist, the signal is sounded.
The pump or exhausting apparatus may be of any known construction, such as
a fan, steam jet, or pump, but by preference a bellows pump is employed, whose
moveable diaphragm is worked either by a crank shaft rotated from one of the
wheel axles or by other suitable known means. The delivery passage of this pump
communicates with a box having a valve according to the position of which the
nir delivered by the pump is either made to pass to the audible signal, so as to sound
it, or is allowed to pass into the atmosphere without operating the signal.
The suction passage of the pump is connected to one end of a chamber whose
other end is connected to the train pipe, and which also communicates by two

page_text: ports provided with valves with two compartments in a casing. These compart-
ments are separated by a partition having a small hole through which they com-
municate, and one side of each is formed of a flexible diaphragm. The valve of the
one compartiment opens into the said chamber, so that when the air is exhausted
from the latter and the train pipe, the air being also exhausted from the said com-
partment, its diaphragm is pressed inwards by the atmospheric pressure, the extent
of such inward motion being however controlled by a pin fixed on the partition
and brought in contact with and thus forcing open a valve in the diaphragm,
when this moves inwards beyond a certain point. At the same time the air is also
exhausted from the other compartment through the small hole in the partition,
causing its diaphragm also to move inwards. This diaphragm carries a pin which
on its inward motion enters the hole in the partition and thus keeps it freed from
obstructions. Each diaphragm is hinged to a lever, one end of which turns on a
fixed fulcrum while the other end of the one connected to the first named diaphragm
is connected to a bell crank actuating the before mentioned valve in the box
communicating with the signalling instrument, the arrangement being such that
while the diaphragm is held in the inward position, owing to the maintenance of
the partial vacuum, its lever holds the said valve open so as to allow the air delivered
by the pump to escape without sounding the signal, but as soon as atmospheric
pressure enters the train pipe the said compartments connected therewith are also filled
with air (entering through the second described compartment by the second named
valve, which opens inwards), and the diaphragms are moved outwards partly by the
entering air and partly by a spring connected to each of the said levers. By the
movement thus imparted to these levers the said valve in the box communicating
with the signal is moved so as to close the exit to the atmosphere and cause the air
from the pump to pass to the signal so as to sound it. The said spring is connected
to the lever actuating the valve at a shorter distance from its fulcrum than the
connection with the other lever, so as to act energetically when moving the first
named lever outwards in the last described operation.
The lengths of train pipe are connected by flexible couplings between the
carriages, so that on these separating, the couplings are opened or the flexible pipe
is broken, thus admitting atmospheric pressure.
In the carriages, branches are formed on the train pipo terminating in an
enlargement, one face of which is closed by a glass or other diaphragm, so that on this
being fractured by a passenger, the air enters the pipe and the signal is sounded.
Or in place of this arrangement a cock or valve may be provided, on actuating
which the air is admitted.