IMPROVED MEANS OF CONDUCTING ELECTRIC CURRENTS THROUGH RAILWAY TRAINS, AND OF ACTUATING SIGNALS OB ALARUMS THEREIN
Year: 1863

page_text: PROVISIONAL SPECIFICATION left by Andrew Edmund Brae at the
Office of the Commissioners of Patents, with his Petition, on the
14th August 1863.
I, ANDREW EDMUND BRAE, of Leeds, in the County of York, do hereby
declare the nature of the said Invention for "IMPROVED MEANS OF CONDUCTING
ELECTRIC CURRENTS THROUGH RAILWAY TRAINS, AND OF ACTUATING SIGNALS OB
ALARUMS THEREIN," to be as follows:-
The first part of my Invention consists in a novel application to railway
trains of the well-known mercurial joint for the purpose of establishing and
preserving true metallic connexion between any two parts of electrical con-
ductors therein, a purpose for which the said mercurial joint presents special
advantages in the simplicity and facility with which the connexion may' be
made, and its subsequent freedom from liability to derangement from the
ordinary concussions and vibrations of the train.
I form a conductor of spiral wire enclosed within india-rubber tubing (but
I do not confine myself to this, as any other flexible conductor will serve) ut
such conductor. I take a sufficient length to stretch loosely from one carriage
in a railway train to the next; I fix it permanently by one of its extremities
to the end or side of a carriage where it may hang pendant when not in use,
and I attach with metallic contact to its other extremity a pin or bar of iron
several inches in length. At the opposite end of the same carriage I fix in 1.
proper insulated support a socket or receiver closed at bottom to retain th
small quantity of fluid mercury, with which it must be charged, and of suc
size and length that the before-mentioned pin shall slide freely in and nearl!

page_text: filling it, shall reach the mercury at bottom, and there remain by its own
weight. I produce permanent metallic connexion between tho pendant pin at
one end and the socket at the other end of the same carriage by means of any
metallic medium, insulated in other respects, and carried from one to the
other along the carriage, interiorly or exteriorly as may be required. Now,
all the carriages in a train being provided in this way with a pin at one end
and a socket at the other, it is evident that between every two carriages an
opposing pair will present themselves, and that metallic connexion may bo
instantly established between them by the mero act of dropping the pin of
one carriage into the socket of the next, and so on throughout the whole
train.
This form of conductor may be used with any description of electrical
signal or alarm, but I prefer to use it in combination with the following
arrangement, which constitutes the second part of my Invention:-I include
within the circuit, in the usual way a galvanic battery and an electro-magnet
capable, when charged thereby, of sustaining a considerable weight. I join
the armature suitable for such a magnet directly to the lever bar of a steami
whistle in such a way, that so long as the armature is upheld by the magnet,
the steam is shut off, but when the galvanic circuit is broken by the separation
of the conductor in any part of the train, the armature and the lever bar will
fall by their own weight, and the steam whistle will be sounded.
In this way
I obtain a wide range of motion in the lover of the steam cock, freedom from
intermediate detents, or other contrivances liable to disturbance from the
concussions of the train, and I use the function of the magnet at its best
possible point, namely, when in nearest contact with its armature.
The third part of my Invention relates in like manner to the avoidance
of spring connexions in any part of the clectrical circuit, and at the same
time to the economizing of apparatus by causing the mercurial junctions,
before described, to serve also as contact breakers, by which signals or alarms
may be given from any carriage in the train. For this purpose I cover the
exterior of the pin with some insulating material so as to prevent its metallic
contact with the socket when withdrawn from the mercury at bottom. I
effect this withdrawal from the interior of the carriages by certain simple cou-
trivances, which, as well as the means I adopt, to produce tell-tales and
indicators of the individual carriages whence alarms may procee.l. For this
purpose I partially withdraw the pin from the socket by the following means,
but I do not confine myself thereto, as there are several other simple con-
trivances by which it may be effected. I take a right-angled lever or
L-shaped crank which turns upon a pivot joint at its angular point, so that.

page_text: when stationary one of its arms is vertical and the other horizontal. The
horizontal arm terminates in a flat ring, which is coincident with and rests
upon the upper rim of the socket, so as to form as it were its orifice; hence
when the pin enters the socket it must pass through the said ring, and rest
therein upon its shoulder. Now, when the upper arm of the crank is drawn
in towards the carriage by a check string, the ring at the extremity of the
other arm is raised, and consequently the pin is lifted to any determinate
height clear of the mercury at bottom. This is applicable to the disjunctive
or circuit-breaking discharge, but it is evident that the same apparatus, by a
reverse movement, will also join the circuit or make the conjunctive discharge.
But it must be noted, that whereas the disjunctive discharge can be effected
at any point in the train, the conjunctive discharge can only be made at one
point, since it is necessary that at every other point the circuit should be
permanently closed. Hence the apparatus just described, when required for
the conjunctive discharge, can be applied only in the guard's van or last
carriage of a train.
For any other point an additional arrangement is necessary, as follows:-
The series of conductors, as described in the first part of my Invention, is
continued all round on both sides of the train, so as to form a complete circuit
of itself, an arrangem' which I prefer in every case, for this reason amongst
others, that each carriage being provided with similar apparatus on both
sides, may be turned with either end forwards without disarranging the
series. It follows that in every carriage there are two similar and parallel
conductors. Then in order to effect the conjunctive discharge, I unite these
two parallel lines by auxiliary conducting pieces laid transversely, and capable
of being conjoined within the carriage by a nippers kept open by a spring,
but which when closed by hand or otherwise come into contact at their
nipping points, and form metallic connexion between the two parallel lines of
conductors at either side of the carriage. Of course it is understood that the
said nippers are provided with platinum or other inoxidable nipping points,
and, as well as the auxiliary conducting pieces between which they are the
medium of junction, are properly insulated. In order that these nippers
should serve as tell-tales to indicate whence the alarm may have emanated, I
sometimes provide them with racks and stoppers, so that when closed they
shall be retained in that position.