IMPROVED MEANS OF CONDUCTING ELECTRIC CURRENTS THROUGH RAILWAY TRAINS, AND OF ACTUATING SIGNALS OR ALARUMS THEREIN
Year: 1865

page_text: York, for the Invention of "IMPROVED MEANS OF CONDUCTING ELECTRIC
CURRENTS THROUGH RAILWAY TRAINS, AND OF ACTUATING SIGNALS OR ALARUMS
THEREIN."
Sealed the 18th August 1865, and dated the 14th June 1865.
COMPLETE SPECIFICATION filed by the said Andrew Edmund Brae at
the Office of the Commissioners of Patents, with his Petition and
Declaration, on the 14th June 1865, pursuant to the 9th Section of
the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ANDREW.
EDMUND BRAE, of Leeds, in the County of York, send greeting.
WHEREAS I am in possession of an Invention for "IMPROVED MEANS OF
CONDUCTING ELECTRIC CURRENTS THROUGH RAILWAY TRAINS, AND OF ACTUATING
SIGNALS OR ALARUMS THEREIN," and have petitioned Her Majesty to grant unto
me, my executors, administrators, and assigns, Her Royal Letters Patent for
the same, and have made solemn Declaration that I am the first and true
Inventor thereof, and that the same is not in use by any other person to my
knowledge.

page_text: NOW KNOW YE, that I, the said Andrew Edmund Brae, do hereby
declare that the following Complete Specification under my hand and seal
fully describes and ascertains the nature of the said Invention, and in what
manner the same is to be performed, in and by the following statement :-
My Invention consists in certain improvements of a previous Invention
under the same title, for which I applied for Letters Patent on the Fourteenth
of August One thousand eight hundred and sixty-three. On that occasion I
described my Invention as consisting in part of an adaptation of the "mercurial
joint" to the purpose of connecting together in metallic union the several
portions of which conductors of electricity through railway trains must
necessarily consist; and I then declared that I formed the said mercurial
joint by loosely dropping an iron pin, pendent from one carriage, to which it
was permanently attached by means of a flexible conducting wire covered
with elastic tubing, into a socket or receiver permanently fixed in a corre-
sponding position to another carriage, and containing at bottom a small
quantity of quicksilver, into which the extremity of the iron pin being
immersed, a metallic contact between the pin and the socket through the
medium of the quicksilver must ensue, which, if repeated with similar pins
and sockets from carriage to carriage all round the train would establish a
continuous metallic circuit, simply and easily put together, certain in junction,
and not liable to disruption from the ordinary vibrations or concussions of a
railway train. Now, I have since discovered that this method of forming the
joint so described by me in my former Specification, though right in principle
is imperfect in two practical points:-First, such an iron pin swaying at the
end of an elastic pendant is objectionably weighty; and, second, the said pin
fitting loosely in the socket does not constitute a sufficient stopper to pre-
vent the possible shaking out of the quicksilver. In order to remove these
defects I now declare that one of the improvements of this my present
Invention is to substitute for the aforesaid iron pin light plug or stopple
covered with india-rubber or other elastic substance, so as to entirely fill and
yet slide easily within the socket. I provide this elastic plug with a con-
venient handle, by which it may be readily thrust into or removed from its
socket. Through the interior of the said plug and handle I carry the flexible
conductor, fixing it therein in such a way that a portion of the wire protrudes
at the end and is necessarily immersed in the quicksilver when the plug is
pushed home; when that has been done the plug is maintained in that
position by its elastic tightness, while at the same time it acts as an effectual
stopper to preserve the quicksilver from disturbance.
8.
Another improvement of my present Invention is to apply the plug and

page_text: socket joint to both ends of the pendants alike. In my aforesaid former
Invention I provided the pendants with a plug at one end only and a fixed
attachment at the other; I now make both attachments alike, the carriages
having sockets at both ends instead of at one only, and the pendants being all
removable. The advantages I obtain by this improvement are simplicity and
uniformity of arrangement, the pendants becoming intermediate connectors,
all of one pattern, the same at both ends, so that spare ones may be provided
to any extent and carried with every train, some of them provided with the
flexible conductor bétween the plugs of considerable length, sufficient to
stretch if need be over and across any stray carriage unprovided with sockets
that may become accidentally included in the train, without the continuity of
the conductors through the other carriages being thereby interrupted.
.
"
Another of my improvements relates to the discharge of the signal, whether
the same be effected by opening the valve of a steam whistle, or by any other
means of attracting attention; and whether the effect be transmitted through
the medium of the conductor I have herein described, or by any other form of
electrical conductor. And whereas such discharge, if too easily produced,
exposes the signal to the risk of being accidentally acted upon by vibration or
concussion, and it is therefore necessary to impart to it considerable power of
resistance; the manner in which I proceeded in my former Invention to obtain
'that resistance I described as follows:-" I include within the circuit in the
usual way a galvanic battery and an clectro-magnet, capable when charged
thereby of sustaining considerable weight. I join the armature suitable to
"such a magnet directly to the lever bar of a steam 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 lever bar will fall by
❝ their own weight and the steam whistle will be sounded." Here the measure
of resistance was the excess of the sustaining power of the magnet over the
weight of the armature, and tlie available power to work the signal was the
weight of the armature when relieved from the resistance of the magnet by
the cessation of its attraction. But I have since discovered that the weight
of the armature when exposed to the disturbances of a train in motion is not
a constant quantity, but is liable to such great alteration from inertia or from
the momentum received from concussion, that the conditions of resistance
might be changed and a danger incurred of creating false signals. Therefore
in my present improvement, so far from depending upon the weight of the
armature to free it from the magnet and to actuate a signal, I neutralize that
Eweight altogether by a peculiar method of counterpoising it, which I shall

page_text: herein-after describe; and I.effect the separation of the armature and the due
discharge of the signal by the reaction of a spring of sufficient tension, firstly,
to overcome with certainty the residual attraction which more or less remains
after the cessation of the galvanic current; and, secondly, to open the valve
of a steam whistle, or otherwise actuate a signal, to which last object the
whole power of the spring becomes available the instant a separation has
taken place between the armature and the magnet. The form of spring
which I use for this purpose is that known as "Salter's spring balance,"
which can be conveniently set to any required tension by means of its
graduated scale, and it is already in use on locomotive engines for the purpose
of restraining the safety valve at any required pressure. The peculiar manner
in which I counterpoise the armature so as to neutralize its momentum is on
the following principle:-When two equal weights are suspended from either
end of a chain or band passing over a fixed pulley above them one must rise
if the other fall, consequently they cannot both obey an impulse in the same
direction communicated to both at the same instant; and as any impetus
received from concussion must be under these conditions, the tendency in one
to obey it must be neutralized by a similar tendency in the other. Now the
way in which I carry out this principle in my present Invention is by two
equal and similar arms radiating side by side from a common centre, but
moving independently thereon. To one of these arms I affix the armature of
the magnet, and to the other arm in close juxtaposition I affix a counterpoise
of similar shape and weight. By this means, upon the principle explained
above, I prevent the armature from receiving any momentum from concussion.
The manner in which I transmit motion to a steam whistle or other signal is
by affixing immoveably upon the arm which carries the armature, and con-
centric therewith, a pulley or roller, or a segmental portion of a pulley or
roller; and to the plug of a steam whistle, elongated if need be, I affix
another pulley or roller; I then connect the two pulleys by an endless chain
or band, pinning it, if necessary, to some point in the circumference of each
pulley to constrain them to move together. And in case the motion of the
armature should not be sufficient in extent to fully open the steam cock of
the whistle, then I make the said pulleys differential or of different diameters,
so as to decrease or increase their comparative ranges of motion.
Having now in the foregoing statement fully described the several improve-
ments which constitute my Invention, I shall next explain the accompanying
Drawings, by a reference to which the way I arrange and carry them into
effect may be more clearly understood.
Fig. 1 is a full sized outline of one of my improved plugs A, with its socket

page_text: or receiver B, and its flexible pendant C. The handle and core of the plug
is of turned wood, but it may be of ebonite or any other light and suitable
material. The lower part, or plug proper, is covered with a piece of india-
rubber tubing a, twitched securely in the notch d. The pendant C is formed
of common flexible gas tube with its inner helix of tinned iron wire, or the
helix may be of copper wire. This flexible conductor, after passing through
the centre of the plug, is shown again at e. The socket B is of iron, but it
may be of glass, potteryware, or any other material, if found more expedient;
the mercury at bottom is shown at f, and at 9 a screw plug to regulate its
quantity; i is a connecting wire, insulated except from the mercury, the use
of which will hereafter appear. Fig. 2 represents one complete carriage body
with the next adjoining ends of two other carriages. Each carriage is per-
manently fitted with four brackets and sockets, one near each of the four
corners. Of these the two at the near side of the central carriage are shown
at b, c, and there are two similarly placed on the far side of the same carriage.
The sockets b, c, are placed by construction in permanent metallic connexion
with each other by means of the insulated connecting wire before mentioned
(i in Fig. 1). This wire being a permanent fixture may be carried over,
under, or within each carriage throughout its entire length, between every
two sockets on the same side (as from 6 to c). When the train is first put
together the socket to the right hand, at each side of each carriage, is
presented ready furnished with a plug and loose pendant (as at a), ready to
be inserted into the adjoining vacant socket of the next carriage. The
completed connexion is shown at c, d. The several connexions being in this
manner completed on both sides of the train, the electric current is conducted
from a to b, from 6 to c, from c to d, and so to the last carriage in the train,
where it crosses transversely to the other side in the manner shown in Fig. 8,
e to f; and returns by similar connexions on the other side, until it has made
a complete circuit. Now it is plain that if this circuit be broken in any part
of the train by the separation of the conductor the current will cease and a
signal be thereby effected; and it is also plain that these connexions from
carriage to carriage, so simply and easily made, may with equal ease and
facility be unmade. They may therefore be used for the double purpose of
junction and disjunction, and so save the expense and complication of separate
apparatus: The manner in which I effect this practically from the interior of
a carriage by the withdrawal of a plug from its socket, is seen at e, d, g, a, b, c,
Fig. 3, which presents a front view of the end of one of the carriages, wherein
e, f, are its two sockets, of which e is that in which the plug and pendant are
generally allowed to remain. This Figure also shows that when the carriage

page_text: is not in use the loose plug hanging from e may be conveniently stretched
across and deposited in the vacant socket f, as well for safe keeping of
itself as for the preservation of the mercury in f from dust or disturbance.
Thus when the carriages are shunted away out of use every socket has a
preservative stopper, and every plug an appropriate place to receive it. The
apparatus for the withdrawal of a plug from the inside is this:-To the handle
of the plug e a chain or wire rope d is attached by hook and eye or some
other simple contrivance easily put on and off. This chain passes over the
pulley g, and terminates in a ring, whence the branch check lines a, b, c, are
led through their respective pulleys into the interior of the carriage.
Ultimately, each check line is passed through some tight stuffing, which
admits of its being pulled but prevents its being pushed back from within, so
that it must remain as evidence of the individual line used in giving an alarm,
while exteriorly, the carriage it proceeded from is identified by the raised
plug, or by a fan which may be easily thrown out from e by the same pull
that lifts the plug, so as to be visible to the whole train. The check lines
are not necessarily limited to three, a greater number may, if necessary,
proceed from, the same ring.
.
Fig. 4 illustrates my improvements in securing and discharging the
signal, and represents in front and in profile the fire-box end of a locomotive
engine where the driver stands; a is an arm carrying the armature d, and
turning upon the centre f, where it is formed into a pulley, from which by an
endless chain its motion is transmitted to another pulley g, fixed upon the plug
of a steam whistle. There is a similar arm at the back of a, not shown in
the Drawing, which moves, concentrically with but independently of a, and
carries the counterpoise as shown in the profile, where c is the counterpoise
and d the armature; they are both supported by the chain and pulley b. The
down pull of the arm a is effected by the spring balance e, which may be set
to a strain of one-third the weight which the electro-magnet c is capable of
safely supporting. The pulleys ƒ and g are made differential to increase the
comparative range of 9, and since a complete revolution is never required the
chain may be pinned to the circumferences of both pulleys, to insure their
moving together. My reasons for using a steam whistle in preference to
any other signal are these; first, it is audible all over the train and attracts
the attention of both guard and driver at the same moment; second, it does
not necessarily give the passengers power to stop the train, but only arouses
attention in the driver to what is going on behind him, and in the guard to
investigate the cause of the signal. The driver receives direction from the
guard alone by certain conventional signals, by flug in daylight, and by lamp

page_text: at night or in tunnels. Thus the steam whistle may fulfil the functions of
two signals at the same moment, whereas by separate signals, first to the
guard, and then from him to the driver, much time, which might be of
imminent importance, must be lost.
Now I do not claim in this Invention the general principle of the
application of a mercurial joint to the purpose described; nor do I claim
the principle of the double use of the junctions as connectors and contact
breakers, those principles having been already divulged and published by me
in my former Invention; but I do claim the several improvements I have
described for the purpose of carrying those principles more practically into
effect, the elastic plug, the equi-sided pendant, the substitution of spring power
for weight to separate the armature from the magnet, and efficiently work the
signal, the counterpoising of the armature for the avoidance of momentum, the
manner of transmitting the motion of the armature to a steam whistle, and
the general arrangement and disposition of apparatus as set forth and described
herein.
In witness whereof, I, the said Andrew Edmund Brae, have hereunto
set my hand and seal, this Ninth day of June, in the year of our
Lord One thousand eight hundred and sixty-five.