IMPROVEMENTS IN SIGNALLING -OR, COMMUNICATING BETWEEN PARTS OF A RAILWAY TRAIN, AND IN THE INSTRU- NENTS AND APPARATUS EMPLOYED FOR SUCH PURPOSE
Year: 1855

page_text: LETTERS PATENT to David Hart, of Trinity Square, in the County of
Middlesex, Gentleman, for the Invention of "IMPROVEMENTS IN SIGNALLING
-OR, COMMUNICATING BETWEEN PARTS OF A RAILWAY TRAIN, AND IN THE INSTRU-
NENTS AND APPARATUS EMPLOYED FOR SUCH PURPOSE."
Sealed the 10th June 1856, and dated the 18th December 1855..
PROVISIONAL SPECIFICATION left by the said David Hart at the Office
of the Commissioners of Patents, with his Petition, on the 18th December
-1855.
I, DAVID HART, of Trinity Square, in the County of Middlesex, Gentleman,
do hereby declare the nature of the said Invention for IMPROVEMENTS IN
SIGNALLING OR COMMUNICATING BETWEEN PARTS OF A RAILWAY TRAIN, AND IN THE
INSTRUMENTS AND APPARATUS EMPLOYED FOR SUCH PURPOSE, to be as follows:-
My Invention, which relates to the 'use of electro-magnetism as a means of
calling into action certain instruments or apparatus to attract the attention
of the engine drivers.audibly. and visibly to certain specific directions or signals
for stopping, starting, or otherwise controlling the engine and its train of
carriages, consists, first, in the application or combination of certain well-
Known mechanical movements and instruments or parts of instruments, as
also well-known kinds of batteries, in a new and peculiar manner, to a certain
signalling apparatus already in use, which is the subject of a-Patent grante:

page_text: to Alexander Symor's, dated the 15th June 1847, and of which Patent I, the
said David Hart, am an assignee. And, secondly, it relates to certain novel
arrangements and improvements in the mode of actuating the pointer or hand
of the dial signal in conjunction with a bell alarum, by which a series of blows
can be communicated to the bell without such local action producing any
motion of the needle or pointer, or effect. upon the electro-magnetic arrange-
ment of the dial instrument. The objects sought to be attained by the
arrangements and combinations according to my Invention are,
1st, the using of one wire or electro-magnetic channel of communication
between the extreme end of the train and the engine instead of two wires to
work the instrument for signalling or directing the engine driver, constructed
according to the Patent granted to Alexander Symons, as aforesaid, when
worked by making circuit.
2nd, the using of one wire or electro-magnetic channel of communication
between the extreme end, of the train and the engine to work the Symons
instrument, with or without my improvements thereto.
3rd, the using of one wire between the extreme end of the train and the
engine or tender for the purpose of working "Symons" instrument, with or
without my improvements, and by which the said signal instrument or
apparatus is called into action by the breaking of the circuit, instead of as
heretofore, and by which means the breaking away of any part of the train
or such other accident will be self-recording.
4th, when the latter object is desired to be effected, that it shall be attained
by the expenditure of the smallest amount of battery or motive power.
5th, that the instruments or apparatus to be applied to the locomotive
engine shall be as small as possible, yet effective; shall be simple in construction,
and for management requiring no watching, winding, or constant attention to
keep it in action; but when it is once applied and properly protected from
exposure to the weather and external injury, it will continue to work correctly
so long as the battery power and the circuit is maintained in a correct and
proper state of efficiency.
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6th, that such apparatus may be worked by the guard from the fore end
as well as the rear of the traini
7th, when desired, the latter part of this arrangement, can, be applied to,
and acted upon-from, the passenger carriage in any part of the train.
All the several 'matters and things connected with my herein-before-partially
'described Invention have relation only to the working of a dial, instrument
'alone, or a 'dial instrument combined with a bell, signal, or alarum, such dial
having one or more directions written, engraved, or otherwise exhibited upon

page_text: its face, and which a pointer or hand directs attention by remaining stationary.
thereat after having been caused to move through a part of or the whole of
the circle of its rotation, and when such pointer, index, or. hand is actuated by,
the alternate making and breaking, or breaking and making,. of an, electric,
electro-magnetic, or galvano-magnetic current, without the intervention of any
clockwork, going barrel, or other such motive power, and whether or not. the
circuit wire of communication be applied according to the Patent of Alexander,
Symons, or in one length over the tops of, or along the sides of, or under the
foot boards of the several carriages composing the train.
The combinations of the several improvements referred to produces the follow-
ing general improvement in signalling or communicating between parts of a
railway train-I only require one wire, and when such wire is applied in
independent pieces affixed to each carriage I only require therefore one pair of
couplings or fastenings between each carriage, and I use the earth through the
iron work of the carriage, the wheel, and the rail for the return current; and
this I am enabled to do by the use of a sand or other similar battery of small
size and power. This battery I prefer to place upon the tender. or engine,
although it may be placed in the guard's van. I have a wheel contact maker
or breaker fitted in the guard's van, with signals or directions similar to and
corresponding with those on the dial instrument fixed upon the engine. I
connect one part of such instrument by means of a metallic wire with the
metal work of the carriage, and so in direct communication with the earth:
The other part is connected to the main line of wire which goes to one of the
poles of the small battery. I connect the other pole of the small battery to
one of the poles of an electro-magnetic. circuit maker with four points of
connection; the other poles are connected, one to the earth and the other two
to the dial and bells apparatus, and the more powerful battery suitable for
working such ȧpparatus. .
When the train arrangement is.to be worked. by the guard completing or
closing the circuit, otherwise open, he turns the instrument in his van, and so
closes it; this causes the weak current from the small battery to flow through
the electro-magnets of the: circuit maker, and attracts the keeper, whereupon
the poles of the more powerful battery, are connected or closed, and it imme-
diately acts upon the bell and dial, causing the first to continue ringing, until
the current is broken, and produces one step motion and corresponding signal
or direction to be indicated on. the dial. But if the train arrangements
or signalling apparatus is to be. called into action by the "breaking" of
the circuit, instead of. by "closing" or "uniting it," this the guard. does
precisely as before when closing, it; and although the effect is, to call into

page_text: action the powerful battery, this results from the difference in the construc-
tion of the instrument I have previously called a "circuit maker," inas-
much as the keeper in the present case is always held in contact, and a weak
current constantly flows from the battery through the wire and by the
earth back again so long as the circuit is kept closed, but so soon as the
circuit is broken, either by the guard, who may wish to transmit a signal or
signals, or by the accidental disruption of the train breaking the wire, imme-
diately the circuit maker has its keeper disengaged from the magnets, and
thereby, as before, calls the larger battery into action, and so works the bell
& dial instruments.
Instead of placing the electro-magnetic movement for striking the. bell
within or under such bell when it is fixed upon a horizontal plate, which plate
also carries the case containing the dial instrument, but fixed vertically, I so
arrange the movements or parts of my combined bell and dial apparatus that
they may be contained within the same case, so that the bell may either be
fixed vertically or horizontally, as most convenient, and need only be of a size
and form suited to give a sufficient alarm or signal.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said David Hart in the Great Seal Patent Office on the
13th June 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, DAVID
HART, of Trinity Square, in the County of Middlesex, Gentleman, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirteenth day of December, in the year of our Lord
One thousand eight hundred and fifty-five, in the nineteenth. ..year. of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said David. Hart, Her special licence that I, the said David Hart, my
executors, administrators, and assigns, or such others as I, the said David
Hart, my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter. during
the term therein expressed, should and lawfully might make,;use, exercise,
and vend, within the United Kingdom of Great Britain and Ireland; the
Channel Islands, and Isle of Man, an Invention for IMPROVEMENTS. IN
SIGNALLING OR COMMUNICATING BETWEEN PARTS OF A RAILWAY TRAIN, AND IN THE

page_text: .
INSTRUMENTS AND APPARATUS EMPLOYED FOR SUCH PURPOSE, upon the condition
(amongst others) that I, the said David Hart, my executors or administrators,
by an instrument in writing under my, or their, or one of their hands and seals,
should particularly describe and ascertain the nature of the said Invention,.
and in what manner the same was to be performed, and cause the same to
be filed in the Great Seal Patent Office within. six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said David Hart, do hereby declaro
the nature of my said Invention, and in what manner the same is to be per-,
formed, to be particularly described and ascertained in and by the following:
statement:-
My Invention, which relates to the use of electro-magnetism as a means of,
calling into action certain instruments or apparatus to attract the attention.
of the engine driver audibly and visibly to certain specific directions or signals
for stoping, starting, or otherwise controling the engine and its train of car-
riages, consists, first, in the application or combination of certain well-known.
mechanical movements and instruments, as also well-known kinds of batteries,
in a new and peculiar manner, to a certain signalling apparatus already in use,:
which is the subject of a Patent granted to Alexander Symons, dated Fifteenth
June, One thousand eight hundred and forty-seven, and of which Patent I,
the said David Hart, am the assignee. And, secondly, it relates to certain.
novel arrangements and improvements in the mode of actuating the pointer or,
hand of a dial signal worked in conjunction with a bell alarum, by which a
series of blows can be communicated to the bell without such local action.
producing any vibration or motion of the needle or pointer, or otherwise.
affecting the electro-magnetic arrangement of the dial instrument.
objects sought to be attained by these improvements are,―
The
First, the using of one wire or electro-magnetic channel of communication.
only between the extreme end or rear of the train and the engine, tender, or
foremost brake van or guard's box, instead of two wires, heretofore necessary.
for working the instruments for signalling or directing the engine driver, con-
structed according to the Patent' granted to Alexander Symons, as aforesaid,.
when worked by making circuit...
Second, the using of one wire or electro-magnetic channel of communication
-between the extreme ends of the train for working the Symons's instruments.
when such instrument is fixed upon the engine, and with or without any
improvements thereto.
Third, the using of one wire between the extreme end of the train and the.
engine or tender on the foremost brake van or guard's box, for the
purpose of

page_text: working Symons's instrument, with or without my improvements, when the
said signal instruments or apparatus fis called into action by the breaking of
the circuit, instead of as heretoforé, and by which means the breaking away
of any part of the train or such other accident will be self-recording.
Fourthly, when the latter object is desired to be effected, that it shall be
attained by the expenditure of the smallest amount of battery or motive
power.
Fifthly, that the instruments or apparatus to be applied to the locomotive
engine shall be as small as possible, yet effective; shall be simple in construc-
tion, and for management requiring no watching, winding, or constant attention
to keep it in action; but when it is once applied and properly protected from.
exposure to the weather and external injury, it will continue to work correctly
so long as the battery power and the circuit is maintained in a correct and
proper state of efficiency..
Sixth, that such apparatus may be worked by the guard in the fore end as
well as at the rear of the train.
Seventh, when desired, the latter part of this arrangement, viz., working by
breaking the circuit, can be applied to, and so as to be acted upon, and called
into action from, the passenger carriage in any part of the train.
All the several matters and things connected with my herein-before partially
described Invention have relation 'only to the working of a dial instrument,
combined with a bell signal or alarum, such.dial having one or more directions
written, engraved, or otherwise exhibited upon its face, and to which a pointer
or hand directs attention by remaining stationary thereat. After having been
caused to move through a part of or the whole of the circle of its rotation, and
when such pointer, index, or hand is actuated by the alternate making and
breaking, or breaking and making, of an electric or electro-magnetic current,
without the intervention of any clockwork, going barrel, or such other. 'motive
power, and whether or not the circuit wire of communication be applied
according to the Patent of Alexander Symons, viz., in distinct pieces attached
to cach carriage, and having at each end of each a clasp-like fastening or in
one length over the tops of, or along the sides of, or under the foot boards of
the several carriages composing the train,
The combination of the several improvements referred to produce the
following general improvements in signalling or communicating between parts
of a railway train:-I only require one wire, and when such wire, is applied
in independent pieces affixed to each carriage I only require therefore one pair
of couplings or fastenings between each carriage, and I use the earth through
the iron work of the carriage, the wheel and the rail for the return current, and

page_text: this Lam enabled to do by the use of a sand or other similar battery of small
size and power. This. battery may either, be placed upon the tender, the
engine,, or in the, guard's van. I have a wheel contact maker or breaker fitted
in the guard's van, with signals or directions similar to and corresponding with
those upon, the dial instrument fixed upon the engine. I connect one part of
such instrument by means of a metallic wire with the metal work of the
carriage,, and so in.direct.communication with the earth; the other part is
connected to the main line of, wire, which, goes to one of the poles of the small
battery. I connect the other pole, of the small battery to one of the poles of
an electro-magnetic circuit maker, which has four points of connection, as
hereafter described; the other poles, are connected, one, viz., that which
continues,from the coil wire of the other pole of the electro-magnet, and
so, completes the circuit to the earth, and the other two poles are connected
respectively to the dial and bell apparatus, and the more powerful battery
suitable, for working such apparatus.
When the train arrangement is to be worked by the guard in the rear of
the train completing or closing the circuit (otherwise open), he turns the
instrument in his van, and so closes it; this causes the weak current from the
small battery to follow through electro-magnets of the circuit. marker and
attracts the keeper, whereupon the poles of the more powerful battery are
connected or closed, and it immediately acts upon the bell and dial, causing
the first to continue ringing.until the current-is broken, and produces one step
motion and corresponding signal, or. direction to be indicated on the dial. But
if the train, arrangements.or.signalling apparatus is to be called into action by
the breaking of the circuit, whether in the rear or fore van, instead of by
closing or making it, this the guard does precisely as, before when closing it,
and although the effect is to call into action the powerful battery, this results
from the difference of construction, of the instrument I have previously called a
circuit maker, inasmuch as the keeper, in the present case is always held in
contact, and a weak current, constantly flows. from the battery through the
wire, and by the earth back again, so long as the circuit is kept closed; but so
soon as the circuit is broken either, by the guard, who may wish to transmit a
signal or signals, or by the accidental disruption of the train breaking the wire,
immediately the circuit maker has its keeper disengaged. from the magnets,
and thereby, as before, calles the larger battery into action, and so works the
bell and dial instruments.....
Instead of placing the clectro-magnetic movement for strikeing the bell
within or, under such bell when it is; fixed upon a horizontal plate, which plate
also carries the case containing the dial instrument, but fixed vertically, I so

page_text: arrange the movements or parts of my combined bell and dial apparatus that
they may be contained within the same case, so that the bell may either be
fixed vertically or horizontally, as most convenient, and need only be of a size
and form suited to a sufficient alarm or signal.
In Sheet One of the accompanying Drawings, Fig. 1 is a plain view, exhibiting
the general arrangement of the apparatus according to this Invention when
both of the batteries and the circuit maker are placed upon the engine, and
when one continuous line of conducting metal wire (properly protected with
gutta percha or other insulating material) is used to connect or make complete
the circuit. The train of carriages is only partly shewn, being broken off.
a, a, the line of wire, extending from end to end of the train; b, the reel
upon which it is wound, having a continuous contact piece or strap c, some
what like the strap of the eccentrics of a steam engine; d, the wire extending
therefrom to one of the connecting studs é of the revolving circuit.maker and
breaker E; g, another connecting stud, by which the wire h, making the circuit
complete from the earth (through the carriage wheel and other metal work), is
secured to the wheel circuit maker and breaker E. The reel 6 is-so con-
structed as to contain a sufficient length of wire to admit of the fullest
extension of the length of the train; or in case of carriages being taken
therefrom, it will readily allow of the wire being wound up without interrupting
the circuit.
By the side of the fire box of the locomotive engine is shewn in the plan,
Fig. 1, the bell and dial signal instruments fixed upon the same plate A, the
larger battery for working the bell and dial instrument B, the relay instru-
ment C, by which circuit is made through the poles of the larger battery, and
the signal instruments when a signal is transmitted by some person in the
train. D, the smaller or relay battery, which need only be a sand battery, of
four or six pairs of plates of small size, producing electricity of only sufficient
intensity to overcome the resistance of the circuit, and convert the soft iron
magnet bars of the relay instruments into electro-magnets.; and when they
are thus under the influence of the electric current, the keeper of the relay
instrument is attracted thereto, and held, firmly against the poles, by which the
circuit is made between the larger battery and the bell and dial instruments,
which are thus set in motion or called into action thereby, as hereafter morė
fully explained.
On reference to the plan, Fig. 1, the main wire a is connected at the back
of the tender by a clasp i to the wire a', running along the tender to the one
pole of the smaller or relay battery D; the other pole is connected by a slior
wirej to one pole of the relay instrument, and from the opposite or corre

page_text: sponding pole is a short wire k, which is connected to the metal work of the
engine and so to the earth, thus making the circuit complete from the extreme
end of the train. There are two other binding screws or connections at the
opposite corners of the relay instrument C; from one of these it will be seen a
wire is connected to the more powerful battery B, and another wire m con-
nects the other binding screw of the relay instrument with the binding screw
on the bell and dial plate A..
:
Fig. 2, Sheet 1, is a side elevation of the wheel circuit maker and breaker
E. It consists of a metal wheel a, with radial arms or pins b, b, &c., by which
it is turned round. This wheel is mounted on a metal standard c; on the upper
side of the wheel is engraved the signals or directions, to correspond with those
engraved upon the dial instrument fixed upon the engine; to the under side is
attached in close metallic contact a small wheel d, having let into it a series of
small non-conducting studs or blocks, by which the flow of the current is
checked when the wheel is so turned that the metal spring e is in contact with
such ivory or other non-conducting material; but when the wheel is futher
turned round, the point of the spring will have presented to it the metallic
surface of that portion of the small wheel which is between the non-conducting
or insulating pins or blocks; the centre standard c being connected with one
of the binding screws f by a short piece of copper wire g; the metal spring e
is connected by similar: means to the other binding screw h, thus enabling the
circuit with the earth to be alternately made or broken, or broken and made;
as may be desired. Fig. 3 is a plan of Fig. 2. The same letters of reference
correspond with the respective parts of the wheel contact maker, Fig. 2.
Fig. 4, Sheet 1, is a plan view of the relay instrument; Fig. 5 is a sidé
elevation of Fig. 4, suitable for working with the arrangement for signalling
from the rear of the train by making circuit; and Fig. 6 is a side elevation of a
relay instrument, similar to Figs. 4 and 5, except that it is suitable for working
the bell and dial. instrument by breaking circuit at any part of the train,
whether it be in the fore or rear guard's van, or by reason of the accidental
breaking away of any part of the train, or from any connection or part of the
circuit wire being under the control. of the passenger by whom such circuit
may be broken, and the bell and dial instrument set in motion or put in
action.
Figs. 7, 8, 9, 10, and 11 are different views of the spring clasp or bracelet-
like fastening, used for connecting the separate length of wire belonging to
each carriage used, in the. single wire arrangement, as seen in Figs. 6 and 7;
Sheet 2, and for connecting the tender to the train wire,, as shewn in Fig. 1,
Sheet 1.

page_text: "
-
The several connections, to and from the various instruments by means of
the insulated copper wires are drawn'in red ink, and such directions are written
thereon in each Figure in Sheet'1, the better to explain the construction,
arrangement, and mode of working the apparatus, and thereby render it
unnecessary to give a detailed description:
The general character of the relay instrument as used for connecting up in
long circuits land telegraph lines is pretty well understood, and renders it
unnecessary to 'describe it here. Fig. 4- is, however, a modification of such
apparatus. as constructed for and so best suited to the present purpose; and
although Fig. 4 has been described as a plan view, yet, as the instrument may
be fixed to the side of the brake van, engine, or tender, it may in such a case
represent an elevation of such an instrument.
"
I will now describe as shortly as possible the construction and mode of
working the relay instrument: Upon a bed piece a is erected the standard b
which carries upon centre bearings at its upper end the lever, c, to which is
fixed the soft iron keeper d, of and belonging to electro-magnets e. The two
poles e¹, e', of the magnet e are secured at their lower ends to the base plate,
and such soft iron poles being wound around or covered with coils of fine
copper wire properly insulated, becomes (upon a current of electricity being
passed through such lengths of wire) an, electro-magnet suitable for the pur-
pose. To one end of the lever ċ is attached a weak re-acting spring f, of
sufficient power to keep the keeper d off the faces of the poles, e³, e', when the
circuit has not been made, as in Fig. 5; and to remove it from the poles of the
magnet and overcome the effects of the residual magnatism from the current
being constantly on, as in Fig. 6. There is also another fixture attached to
the bed piece or plate, viz., the standard?ġ; with the adjustable, points h and h³.
All these standards and.fixings are adjustable, and are insulated and made
electrically independant, the one from the other, and from the base plate by
means of ivory: or ebony blocks, and the connecting wires i.and k,are, respec-
tively. carried from their corresponding binding screws, as are also the short
connecting wires'l and m belonging to the electro-magnet. o and p are the
two connecting or binding. screws. connected with the magnet; and q and rare
those corresponding with the i and k, which run, in the direction indicated by
the directions written thereon. Now, in Fig. 5 the relay instrument is.shown
in the condition in which it is when out of use and not at work, conveying a
signal and working the bell alarum, that is to say, the keeper is held from off
the poles of the. electro-magnet by the spring f, and the opposite end of
the lever c. rests against insulated point h² of the standard g; but when the
current is transmitted, through the coils surrounding the poles of the magnet, e,

page_text: the keeper is attracted, and brought into: contact with the platenized point h
of the same standard, and so makes circuit with the more powerful battery:;
and the bell and dial apparatus by causing the current from the stronger
battery to flow through the wire r, &c: tok, and up the standard 6, passes
through the metal:arm for lever c; through the points, and the standard g, ito
the short wire:t, and the wire q, which is connected with the bell and dial
instrument, and thus, causing the current tor flow through the coils of the
smaller magnets of thér:dial instrument, branches off to the larger magnets
of the bell'signal; causing the needle of the dial instrument first to make one
step or portion of a rotation; and setting in action, the independant make and
break arrangement of the hammer of the bell; by which a series of blows are
communicated without interrupting or interfering with the action of the needle
and dial instrument, which remains inactive until the current is again stopped
by the breaking of the circuit, when "the needle becomes re-set ready for the
next step, which will be performed when the current is again transmitted.
But in Fig. 6a variation is made to suit the circumstance of its being intended
to be used with the circuit constantly made whilst the train is in motion, a
weak current being allowed to pass through the coils of the magnet.. e retains
the keeper d in contact with: the poles el; et, and the end of the lever c'then
rests upon the insulated point h of ithe metal standard.g; but immediately.
upon the current being interrupted by the guard in either or any of the vans,
or by the accidental disruption of the tram; the poles ee, cease to hold the.
keeper d, which is instantly drawn.up from off their faces by the spring f, and
the point of the lever c'immediately comes into contact with the platenized
point h', and thus makes circuit between the more powerful battery and the
bell and dial, as just described in explaining Fig. 5. It is in the form.of
Fig. 6 that the relay instrument made according to my Invention will be found
more generally useful to work in connection with the improved arrangement
of tapparatus.
•
In Sheet 2, Fig. 1 is a plan.of the bell and dial instruments combined and
fixed upon the same sole plate.or base piece; Fig. 2.being an elevation of
the bell part; the dial case being removed..and the bell cut in half the better.
to exhibit the construction of the parts; Fig. 8 is an external view or front
elevation of Fig.11; and exhibits the arrangement of the signals as engraved
upon the dial.;. Fig: 4 is a. side view. of the.movement for working the needle
pointer or hand of the dial instrument; and Fig. 5 is an elevation of Fig. 4,
the front plate being removed.
In Figs. 1 and 2 it will
to.binding screws é and d.
***
:
be. seen that there are two.wires a and b attached
From these binding. screws, but .upon the under

page_text: side of the bed plate e, the wires a¹ and run direct to the two poles of the
magnet contained within the case of the dial instrument, but the wires a" 'and.
6 branch off, as shewn, one to the large magnet g of the bell apparatus, and
the other to the platef of the make and break motion, upon which plate the
spring i at the back of the keeper k comes in contact when the keeper has
fallen from off the poles of the magnet whenever the current is interupted,
however instantaneously, the rapidity of motion and depth of stroke of the
hammer n against the bell m being adjusted by it and by the aid of the set.
screw Z, and the re-acting spring o. The dial instrument, Figs. 4 and 5, is
protected in a box or case, as shewn at Fig. 3, the dial being covered with
glass. The action is as follows:-The wires a¹ and 6' are connected to the
magnet p; the keeper is formed at the short end of the lever arm s, the upper.
end of which has a tooth or picker, which comes into contact with one of the.
teeth of a small leaved pinion t, which is mounted on the spindle of the pointer,
the pinion having the same number of teeth as there are signals engraved upon
the dial. Each time the current passes through the magnetic coils the picker
of the levers moves one tooth of the pinion at a time; and when the current
is broken, the re-acting spring v behind the lever s throws it back, and allows
the small friction roller w to fall into or between the top pair of teeth or leaves
of the pinion t, for the purpose of retaining the pinion and the pointer or
index hand in the position into which it has been moved by the picker of the
lever s. The friction roller w is mounted on the end of a lever, which is kept
to its work by a weak back spring, as shewn.
Fig. 6 is a side view of two buffer heads, shewing the mode of attaching
the clasps thereto by means of chains, with a view to prevent the wires and
fittings becoming strained, from being unsupported whilst the carriages are in
motion.
Fig. 7 is a plan view of part of a train, somewhat similar to that shewn at
Fig. 1, Sheet 1, but with the following improvements:-1st, instead of having
the bell and dial instruments connected upon the same horizontal sole plate or
case piece, and placed behind the screen board or weather board, as in Fig. 1,
Sheet 1, I prefer to place the dial instrument on the front of the screen or
weather board, and on one side or other of the centre line of the engine,
whilst the bell instrument is placed flat, against the front of the screen board,
instead of being fixed horizontally and behind it. 2nd, the batteries are both
removed, together with the relay instrument, from off the engine or tender
where there is a very considerable amount of motion, and are placed, as shown,
in boxes within the guard's van, where there is but little motion, thus avoiding
the shocks occasioned to the relay instrument, and the washing out of the acid

page_text: 5
when a fluid battery is used. In this arrangement, when both batteries are
removed, two wires become necessary along the length of the engine and to
the back of the tender, as shewn, but only one wire otherwise throughout the
length of the train is required..
•
The mode. of connecting the two wires from the engine to the first: van is
shewn, and the larger battery and relay instrument are connected as before
described. The one wire from the magnet end of the relay instrument is
carried down to the earth. through the horn plate and the wheel; the. other
and corresponding pole of the relay instrument is connected with the small
battery, the other pole of the small. battery being connected with the single
wire which runs along the length of the train. A wheel circuit maker
and breaker may be inserted. in any number of parts of the main line of wire
when the apparatus is worked by breaking the circuit, as before described:
The bell, dial, large battery, relay. instrument, small or relay.battery, wheel
circuit maker and breaker, &c. are in this plan defined by the same capital
letters as were used in describing the arrangement in Fig. 1, Sheet 1, except
that the bell is A, and the dial A¹, in the present..plan; but the mode of con
pecting up is the same between the several instruments... :
Fig. 8 is a front view of the screen or weather board, and exhibits the bell
A and the dial A fixed, as just described.
Having.now described the various parts of this Invention, and by the aid
of Drawings shewn their action, having also described the various apparatus
and things used in connection with my Invention, and which it has been
necessary to describe and explain for the better understanding thereof, I wish
it to be understood that I do not claim generally such parts of the arrange-
ment described as may be individually well known or in use for other purposes;
nor do I claim the signalling to the engine driver, by causing a pointer or index
hand to revolve upon a dial by a step by step motion, produced by the trans-
mission of a current of electricity, however produced, through or around the
poles of electro-magnets, such dial having distinct direction instructions or
signals engraved, written, or painted thereupon, when such dial is used alone
or in conjunction with a bell or other alarum, when such signal apparatus is
worked with one battery only, and two lines of metallic wire running along
the length of the train. But I claim as my Invention,-
Firstly, the combination of parts and the arrangement of the apparatus as
herein described, by which I am enabled to communicate distinctly visable
and readable signals or instructions from any part of the train from which it
may be pre-arranged to transmit such signals to the engine driver, by means
. of one metallic line of connection only between the extreme end of the train
-

page_text: and the smaller or relay battery, whether it be placed in the foremost van or
upon the engine or tender.
J
Secondly,. L claim the use of. an. electro-magnetic relay instrument as
described, when employed for calling into action a more powerful battery, by
which a dial signal, as described, or radial signal and bell, or other. alarum in
conjunction therewith, is worked or set in motion at pleasure by the making or
breaking of the circuit,, as.may. be arranged when such. relay instrument and
apparatus is employed for signalling upon a railway train..
Thirdly, I claim the novel combination, and arrangement of parts described
and illustrated by Figs. 1; 2, 8, 4, 5, 6,17 and 8, in Sheet 2, and in Figs. 1, 2,
3, 4, 5 and 6, in Sheet 1, as being improvements upon the invention for which
a Patent was granted to Alexander Symons, as aforesaid.
Fourthly, I claim the construction and arrangement of relay instrument as
described, or its mechanical equivalent, when used as a self-recording, arrange-
iment, for the purpose of indicating the accidental. breaking away of..any part
of the train, and by which means the bell and dial apparatus when. used,
together.or separately, may be worked from any part of a railway train..
In witness whereof, I, the said David Hart, have hereunto set my
hand an seal, this Thirteenth day of June, in the year of our Lord
One thousand eight hundred and fifty-six.
DAVID HART. (L.s.)