IMPROVEMENTS IN APPARATUS OR MEANS FOR COM- MUNICATING BETWEEN THE PASSENGERS AND THE GUARDS AND ENGINE DRIVERS OF RAILWAY TRAINS
Year: 1877

page_text: PROVISIONAL SPECIFICATION left by John James Hall at the Office of
the Commissioners of Patents on the 27th March 1877.
JOHN JAMES HALL, of Datchet, in the County of Buckingham, Fellow of the
Meteorological Society. "IMPROVEMENTS IN APPARATUS OR MEANS FOR COM-
MUNICATING BETWEEN THE PASSENGERS AND THE GUARDS AND ENGINE DRIVERS OF
RAILWAY TRAINS."
This Invention relates to a peculiar combination or arrangement and adaptation
of apparatus whereby in case of accident or distress a passenger may call the
attention of the guard and engine driver of a railway train with the view of stopping
the train and procuring assistance.
In carrying out my said Invention I fix on the roof of each carriage, by pre-
ference on each side, an iron frame or box with a hinged lid or cover, such box
containing a powerful detonating signal and red disc, the detonator being exploded
and the disc raised to a conspicuous position by pulling a copper wire, cord, or other
flexible connection extending from end to end of the carriage, and situate under the
roof boards on both sides of each compartment. Each of these cords is connected
in any convenient manner with a sliding spring bolt for releasing the signal
apparatus in the box in connection therewith. The said cords, after passing through
each compartment, are connected at their extremities to spiral tension springs so as
to yield slightly when pulled by a passenger. As each of these cords communicates
with a separate signal apparatus, double security is ensured.
If desired a separate signal apparatus may be fitted over each compartment, and
each apparatus be acted upon by a separate pendent cord and ring or handle. In
the former case an additional arm or semaphore may be fitted to each compartiment,
and be displayed simultaneously with the discharge of the signal apparatus in order
to indicate the particular compartment from which such apparatus was actuated.
In the latter case, however, such additional arm or semaphore would not be
requisite as the state of the particular signal apparatus released would be a sufficient
indication.
The signal apparatus is entirely self contained, and is comprised within the
compass of the aforesaid box, the lid of which cannot be closed until the apparatus
within is properly set or adjusted. This apparatus consists of a rocking shaft which
is caused to make about half a revolution by the action of coiled or other springs on
•

page_text: being released. An arm rigidly secured to the rocking shaft carries a hammer head
for exploding a detonator, and is further provided with two bevelled catches which
engage with the before-mentioned sliding spring bolt or other convenient contrivance
for holding the hammer back when set, and for releasing it when required for action.
An arm carrying a red signal disc also turns loosely upon the rocking shaft so as to
be free to lie horizontally underneath, the hammer shank when set, and to be brought
into a vertical position so as to display the disc when released, such motion being
derived from a projection or projections of the boss of the hammer shank coming in
contact with corresponding projections on the arm of the disc, and carrying such
arın round with them through an are of about 90°, suitable fixed stops being pro-
vided for preventing the arm of the disc from passing the vertical position. The
said mechanism is entirely protected from dust and from the weather by the lid of
the box, which flys open so soon as the withdrawal of the sliding bolt or catch has
released the hammer. The hammer, when released, describes about a half revolution,
and descends upon and explodes a detonator placed upon an anvil at the opposite
end of the box, whilst at the same time the red disc assumes a vertical position and
is displayed to the view of the guard or driver, or both.
I also propose, if found desirable, to combine with the before-described apparatus
an arrangement for simultaneously displaying a powerful red or other light, the well-
known composition for which is contained in an ordinary casc, fitted inside a metal
tube or holder, secured to the back of the signal disc so as to lie between the arms
of the hammer shank (which in this case should be made double or forked) when
the apparatus is set or adjusted. The said composition is ignited by friction or
percussion, and with a view to increasing the intensity of the light, I introduce
therein magnesium in the form of strips, wire, or otherwise, whereby the light is
rendered specially available at night or in foggy weather, and in tunnels where the
steam from the engine would reflect it against the roof glass of the brake vans.
The metal tube which contains the composition for the light is closed at its inner
end and open at the outer end, and contains an internal helical spring and propeller
for forcing outwards the composition as soon as ignited, the composition case being
screwed at its base to a screw projecting from the centre of the propeller so as to
prevent it from becoming detached when expelled by the action of the spring. To
the head of the hammer shank there is jointed a roughened piece of metal or other
suitable material for igniting the composition by friction, the said roughened surface.
being rapidly drawn across a piece of priming on the end of the composition case by
the motion of the hammer. When the entire apparatus is set or adjusted, the com-
position case is held pressed back inside the metal tube or holder by the presence of
the roughened igniting surface, which serves for the time being as a species of lid or
cover to the open end of the tube.
A leading characteristic of my Invention consists in the peculiar manner in
which I protect the detonator and the chemical composition for producing the red
light from atmospheric influences. I protect the detonator by means of a gun-
metal holder provided with an annular channel containing mercury, or glycerine,
or other suitable fluid for making a hydraulic seal and an inverted collapsible thin
metal cup which covers the detonator and is sealed by dipping into the mercury or
other fluid. If found requisite the said inverted cap may be held down on its place
by passing a piece of wire over it, such wire being threaded at the ends through
holes in the rim of the holder. The composition for producing the red light is pro-
tected by being enclosed in the before-mentioned metal tube, which is permanently
closed at one end and temporarily closed at the other end by a leather or other pad
on the upper portion of the jointed ignitor. I thus ensure the perfect action of the
detonator and of the light at any interval of time.
The several parts or elements of my said apparatus are all made in duplicate,
and are interchangeable from one apparatus to another, so that in case of fracture
the damaged part or parts may be readily restored.
The advantages afforded by my said Invention are as follows:-
1. The apparatus is self-contained, its arrangements being in no way connected

page_text: with or dependent on those of any other vehicle in the train, hence carriages
may be attached or detached at junctions, road-side stations or sidings, without
the slightest additional trouble.
2. The disc having been elevated cannot be restored from the interior of a
carriage, it therefore continues to be exhibited until visited by the guard.
3. The visual absence of a red disc on any carriage or compartment indicates
alike to guards, drivers, and station officials, that the hammer or exploder applying
to such carriage or compartment is locked and in readiness for use, it being rendered
impossible to close the lid or cover of the box until the apparatus has been properly
set or adjusted.