IMPROVEMENTS IN TELEGRAPHIC SIGNALLING APPARATUS
Year: 1885

page_text: し
.
I LUIS DE MORAES GOMES FERREIRA of 63 Clarence Road, Lower Clapton in
the County of Middlesex, Electrical Engineer do hereby declare the nature of my
invention for "IMPROVEMENTS IN TELEGRAPHIC SIGNALLING APPARATUS," to be
as follows:
The present invention relates to improvements in telegraphic signalling apparatus
and more particularly to what are known as dial telegraph instruments.
In such instruments a dial is marked with a number of letters, signs or sets of
words, and a pointer is moved by the operator to indicate one or other of the said
letters signs &c on the dial of the transmitter, electric impulses being transmitted
at the same time to the receiving station and a pointer being caused to indicate
corresponding letters or signs on the dial of the receiver.
In the Froment dial machine the pointer of the transmitter is directly moved by
the operator in the direction of the hands of a clock thereby setting a make-and-
break device in action, and causing a set of electric impulses to be sent along the
line wire to the receiver where an arrangement of pawl and ratchet wheel, or an
escapement device analogous to a clockwork escapement is electrically actuated and
causes the pointer of the receiver to move synchronously step-by-step with the
pointer of the transmitter. With this machine a continuous battery current is
used.
In the Wheatstone dial telegraph on the contrary, the electrical impulses are
produced by a magneto-electric machine driven by the operator, the pointer being
arrested at the desired letter or sign on the dial by pushing in one or another of a
series of studs or buttons arranged in a circle.
In this instrument two separate dials are used, one for the contact studs or
buttons and another for the indicator. The operator moreover has to use both
hands, the one to continuously work the magneto-electric machine within the case
by turning a handle, and the other to manipulate the appropriate contact studs
or buttons.
Now the object of my invention is to provide a dial telegraph of very simple
construction and positive action, which can be worked with less labour to the
operator than heretofore.
"
In carrying out my invention I employ a single dial and a set of contact studs
or buttons arranged after the manner of the Wheatstone machine, or in such
manner that the pushing in of one stud to make contact will ensure the breaking
TD 1 133

page_text: contact of all the other studs, and I combine therewith a battery or other source
of electricity of any suitable kind.
My invention relates more particularly to the construction and arrangement of
the mechanism for imparting the step-by-step movement to the pointer of the
transmitting instrument, whereby the operator has merely to press in the stud or
button corresponding to the letter or signal he desires to transmit, and does not
require to move the pointer round, either directly by turning it with his hand, or
indirectly by the turning of the magneto-electric machine.
This result I obtain by employing a pallet or armature suspended between the
pole pieces of a pair of electro magnets, or the two ends of a horse shoe magnet,
which are so wound that their pole pieces are always of different polarity, and
through the coils of which a current is sent by impulses alternately in opposite
directions. The pendent pallet or armature on the contrary has a fixed polarity
given to it by means of a permanent or electro magnet, whose pole piece partially
encloses the said pallet while yet allowing it to vibrate freely.
The result of this arrangement is that with every impulse of the alternately
reversed current through the electro magnets the pallet is repelled by one and
attracted by the other, thus ensuring its vibration in a very positive and direct
manner. Projecting from the vibrating pallet is a pair of pins arranged to engage
with and rock a current-reverser at the moment when the pallet has vibrated to
nearly its full extent in one direction, or the other; thus automatically switching
the current to flow in the direction required for maintaining the pallet in vibration
or oscillation so long as is necessary.
I lay great stress upon the reversal of the battery current, as it enables me
to dispense with springs and removes all the inconveniences due to residual
magnetism.
The pointer or indicator is driven in one direction by a pawl and ratchet, an
escapement device, or equivalent means actuated by the oscillation of the arbor or
spindle on which the vibrating armature is fixed, and its movement is arrested in
the following manner. A disc of copper or conducting material is fixed on the
arbor of the pointer and when a stud or button is pushed in, contact is established
between the said stud and the copper disc. So soon as this is done the current
passes to the actuating mechanism, and the indicator abor and with it the copper
disc, moves round with a step-by-step movement.
Inserted in or fixed to the copper disc is a piece of insulating material such as
ivory, and this insulating piece is always in line with the indicator hand, or is
maintained in a definite relation thereto, so that when the said hand reaches the
depressed contact stud, the insulating surface of the disc will have reached the
metallic contact operated by the said stud and the circuit will be interrupted thus
allowing the hand to stop so soon as it has reached the required letter or sign.
On another stud being pushed in, the first named stud will be automatically
raised and contact will be established by the second stud, thereby starting the
vibrating pallet and moving round the indicator to the letter represented by the
said stud, when the insulating surface will again interpose to break the circuit and
automatically arrest the pointer. When an electric gong is used with the apparatus,
as will generally be the case, it is operated when the pointer leaves or returns to
zero and is otherwise out of circuit, thus reducing the ringing to the minimum
necessary for efficiency and convenience in working. I effect this by a disc of
insulating material moving synchronously with the pointer and provided with two
contact plates in electric connection with a metallic core and spindle. These plates
are close together and when the indicator at zero they are equidistant therefrom,
one on either side. Thus on leaving zero the left hand stud will be moved and
make contact in passing with a rubber or collector, after which the bell will be out
of circuit until the pointer is just returning to zero, when the right hand plate will
meet the rubber and by establishing the circuit again cause the bell to ring.
I would remark that I do not limit myself to the precise arrangement of contact
studs or buttons, nor to the means employed for ensuring that only one at a time

page_text: shall make contact with my copper circuit making-and-breaking disc, though
I prefer to use an arrangement analogous to that employed in the Wheatstone
dial telegraph, in combination with a series of bell cranks, one for each stud or
button, and a series of conducting springs arranged radially of the rotating
copper disc
I would observe that I may give a special form to the pole pieces of the electro
magnets by which the pendent pallet or armature of fixed polarity is caused to
vibrate, causing them to project in part so as to always slightly underlie the said
armature so. that the said projecting part thereof may obtain command of the
pallet and start it in its reverse movement directly the current through the said
magnets is automatically reversed as above indicated.
The receiver resembles the transmitter in appearance, but when applied to railway
signalling requires no contact studs or current reverser.
From the foregoing it will be seen that the operator has only to push in the
proper studs or buttons in succession, all the subsequent movements being
automatically performed.
It is obvious that the apparatus is suitable for a variety of signalling purposes,
among which may be mentioned the sending of fire alarm signals from a number of
outposts to a central station.
In this case the transmitting stations would only require one stud or button
each, and the current. reverser and alarm bell would be located at the central
station, the principle of operation remaining as before. To enable any fault in
the line to be detected I allow the battery current to flow through the line and
actuate a galvanometer or other indicator, passing the current through a very high
resistance before going to earth, to economize current and prevent the apparatus
from working until required.

page_text: Improvements in Telegraphic Signalling Apparatus.
I LUIS DE MORAES GOMES FERREIRA of 63 Clarence Road, Lower Clapton in
the County of Middlesex, Electrical Engineer do hereby declare the nature of this
invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:―
The present invention relates more particularly to that class of electric telegraphic
signalling apparatus which are known as dial telegraph instruments.
In these instruments, a needle is caused to point to a letter, sign, or word upon
the dial of a transmitter, and at the same time another needle is caused, by electric
impulses, to point to a corresponding letter, sign, or word upon the dial of a
receiver at a distance.
In the Froment dial machine, the needle of the transmitter is directly moved by
the operator in the direction of the hands of a clock, thereby setting a make and
break device in action, and causing a set of electric impulses of the same sign to
be sent along the line wire to the receiver, where an arrangement of pawl and
ratchet wheel, or an escapement device analogous to a clock work escapement, is
electrically actuated, causing the needle of the receiver to move synchronously step
by step with the needle of the transmitter.
This apparatus, however, includes clockwork mechanism of a more or less
complicated nature, and transmits a continuous electric current, which is obtained
from a battery.
Wheatstone obtains alternating electric impulses for his dial telegraph by means
of a magneto electric machine worked by the operator, who is thus somewhat
hampered in the manipulation of his instrument. This instrument has a pair of
dials, one carrying a pointer, the other being provided with a number of contact
studs or buttons arranged in a circle.-The pointer is arrested at any desired sign
on its dial by the depression of the appropriate contact stud.
Now the object of my invention is to provide a dial telegraph of very simple
construction and positive action, which is worked by an alternating electric current
without labour to the operator.
To this end I employ a transmitting instrument and a receiving instrument, the
construction of which, as adapted for use in Railway signalling, I am now about to
describe with reference to Sheet I of the accompanying drawings.
Sheet II of the drawings refers to another application of the invention, which
will be hereinafter dealt with.
Figs. 1 and 1ª are external views of the transmitter and receiver respectively,
each shewing a dial provided with an indicating needle.-The dials of the
instruments are alike in respect of the signs, words, or letters thereon, so that the
needles, which are arranged to act in unison, always point to the same sign in both
instruments.
Figs. 2 and 2 shew the instruments as seen from the back, with the case and
some of the parts removed.
Figs. 3 and 3ª are side views.
Fig. 4 is a detached view of the current reverser.
Figs. 5 to 12 are detail views of parts to be presently described.

page_text: The transmitter is provided with contact studs A (in this case, seven in number)
placed around the dial opposite the various spaces for signs which it may be
desired to indicate at the receiver.
Each of these studs A bears against the tail of a bell crank lever a (see Fig. 3),
pivotted to a bracket piece mounted upon the inner face of the transmitter case,
and the bell crauk levers are each provided with a contact spring b adapted to
come into contact with a metal disc B, mounted upon, but insulated from the
arbor D of the indicating needle, when the bell crank lever is rocked by the
pressing action of one of the studs A.-The shorter ends of the bell crank levers a
overlie an endless chain e carried by a circular roller bearing frame E. This chain
is just sufficiently slack to allow one lever, and one lever only, at a time, to be
rocked, to bring its spring b into contact with the disc B. Thus, the depression
of one of the studs A, and the consequent rocking of the lever a in connection
therewith, will tighten the chain e, and ensure the withdrawal of any other lever a,
and its stud A, to its normal position of inaction. The slack of the chain is
regulated by an extra roller carried by a screw operated lever hinged to the
circular frame. The bell crank levers a are retained in their acting position by
means of the springs a¹, as shewn in Fig. 3.--The metal disc B has on its face a
plug of insulating material for the purpose to be presently described, but there is
an insulated spring b¹ in constant connection with the back of the said metal disc
(see Figs. 5 and 6).
.
The transmitter is provided with a current reverser, which is clearly shown in
Fig. 4. It consists of a pair of metallic springs c c, the outer ends of which are
pivotted to insulated posts C and C¹, the inner ends being carried in slots on
opposite sides of an insulating block c¹ pivotted to the framing of the instrument.
Above and below the springs c c are insulated contact points k k¹ k² k³ (k being
connected to k³, and k¹ to k³), so arranged that the partial rotation of the block c¹
will tip the springs c c up or down, as the case may be, into contact with the
points k k or k
〃
Projecting upwardly from the block c¹ is an iron arm or keeper c², which
oscillates between the poles of a small permanent horse shoe magnet C³, and
adheres thereto, for the purpose of maintaining perfect contact between the
springs c c and the contact points when the keeper c² is thrown to and fro by the
pins upon the plate L, as hereinafter described.
The above mentioned parts are peculiar to the transmitter.-I will now, however,
proceed to describe the parts common to both transmitter and receiver, and also
the parts peculiar to the receiver.
F is an electro magnet of horse shoe form, having pole pieces of peculiar
construction. Pendent above the magnet F is a polarized rocking armature G
fixed upon an arbor g mounted in bearings in the framing of the instrument. The
armature G receives its polarity from permanent magnets H, one pole of which
the upper part of the armature G partially embraces, as shewn in Figs. 3 and 3*,
and more clearly in the enlarged detached views, Figs. 11 and 12.
Upon the arborg of the armature G is a pallet g¹, best shewn in Figs. 9 and 10,
which engages with, and rotates step by step an escapement wheel & fixed upon
the arbor D of the indicating needle. Upon the arbor g is also an upwardly
projecting weighted_arm or balance , which, in the transmitter, is connected with,
and rocks the plate L above alluded to.
The action of the apparatus is as follows:-One terminal of the electro magnet F.
of the transmitter is in connection, through the current reverser, with one pole of
a galvanic battery.-The other terminal is in connection with the disc B on the
arbor D of the indicating needle, through the contact spring b'. When one of the
studs A is depressed, contact is made through the spring b between the disc B and
the framing and bed plate of the instrument, and from thence to earth. The
opposite pole of the battery is connected through the current reverser to the line
wire leading to the electro magnet F of the receiver and thence to earth,

page_text: It will thus be seen that the depression of one of the studs A will close the
circuit. Immediately the circuit is closed, the polarized armature G is attracted
and repelled by the opposite poles of the electro magnet F in both instruments.―
This forcing over of the armature G rocks the arbor g, and with it the pallet g¹, which
rotates the wheel d, thereby moving the indicating needle, which is on the same
arbor D, one step.-The balance weight serves to make the movement of the
armature G regular and positive.
The rocking of the plate L causes the pins thereon alternately to strike the
keeper c², and thereby change the position of the springs c c of the current
reverser, but this does not take place until the extent of movement of the arbor
carrying the armature G and plate L, is nearly complete.
This is effected by arranging the pins ll somewhat wide apart, the object being
to ensure a prolonged flow of electric current at each reversal.
The reversal of the currents will be more clearly understood by referring to the
diagram on Sheet I* of the accompanying drawings.
In this diagram I have shewn the positive pole of a battery connected to the
post C of the transmitter, while the negative pole is similarly connected to the
post C¹.
The springs b b are connected to the bed or foundation plate of the apparatus,
which is in turn connected by a wire to earth.-The insulated spring b¹ connected
to one of the terminals of the electro magnet F, the other terminal being connected
to the posts k¹ and ³; the other two posts k and k² are connected with the line
wire. The terminals of the electro magnet F of the receiving instrument are
respectively connected to the line wire, and to earth.
It will now be understood, that supposing the parts to be in the position drawn
in the diagram, and one of the springs 6 be brought into contact with the disc B,
the current will take the direction indicated by the drawn arrows, viz:-from the
positive pole of the battery to the post C, thence, by the spring c, to post k¹, round
the electro-magnet F of the transmitter, to the spring b¹, through the disc B to the
contact spring b, and so, by the foundation plate, to earth; by the earth it will
pass through the coils of the magnet F of the receiving instrument to the line, back
to the post k of the transmitter, thence, by the spring c, to the post C¹, and so to
the negative pole of the battery.
When the current reverser takes the position shewn in dotted lines, the current
from the battery will pass through the spring c to the post k, and thence through
the line wire to the receiving instrument and earth, the return being by the base
plate of the transmitter disc B, contact spring b¹, through the coils of the electro
magnet, posts k³ and C', to the battery.
The reversal of the electric current changes the polarity of the electro magnet F
in each instrument, which consequently causes it to act upon and rock the
armature G in the opposite direction, thus rotating, through the arbor g, pallet g³,
and escapement wheel d, the indicating needle one step further.
This synchronous step by step movement of both the needles is continued until
the circuit is broken, which does not take place until the needles have reached the
sign desired to be indicated opposite the depressed stud A.-The breaking of the
circuit is effected by the insulating plug upon the face of the disc B of the trans-
mitter before mentioned, which is in line with the indicating needle, coming under
the contact spring b in connection with the depressed stud.-Immediately the
circuit is broken, the electro magnets F will cease to be excited, and will no longer
operate the armature G; thus the motion of the indicating needles will be
instantly arrested. The depression of another stud A will close circuit through
another contact spring b, and the first stud will be driven out by the action of the
chain e operating upon the short end of the bell crank lever a, as above explained.
The instruments will then operate until arrested by the insulating plug coming
under the spring of the depressed stud, as before.
The receiving instrument is also provided with an electric bell or gong M, which
is caused to ring only when the needle leaves or approaches zero, and is at other

page_text: times out of circuit, thus reducing the ringing to a minimum, an advantage when
several instruments are located in one apartment.
To operate this gong M, a small local battery and an electro magnet N are
provided, which are thrown into aétion in the following manner:-A disc B✶ is
fixed upon and rotates with the arbor D of the indicating needle. This disc is of
metal, completely faced with insulating material, except at two points near together
(see Fig. 7).-The disc B* is so set upon the arbor D that the needle is in line with
the space between the two metallic points.-A suitably placed insulated contact
finger 6 is in electrical connection with one end of the coil of the local electro
magnet, the other end being in electrical connection with say the negative pole of
the local battery.-When the needle leaves zero, and the disc B* begins to rotate
with the arbor D, one metallic point comes in contact with the finger 61* and closes
the local circuit through the metallic framing to which the opposite or positive pole
of the local battery is connected.-The electro-magnet N thus excited, attracts an
armaturen, suitably mounted on a spring, and carrying a hammer n² (see Fig. 2º),
which is thus caused to strike the gong M.-The continued rotation of the disc B*
removes the metallic point from contact with the finger 61*, thereby breaking
circuit, and stopping the ringing of the gong.-As the needle again approaches zero,
the second metallic point comes in contact with the finger 61*, and the gong is
again rung, and stopped in a similar manner.
For the purpose of adjusting the position of the needle of the receiver to
correspond with that of the transmitter, I provide a lever * to operate mechanically.
the escapement device through the balance arm ¹ (see Fig. 3º).
I prefer to make the polar extension pieces of the electro-magnet F of the
peculiar form shewn more clearly in the enlarged view Fig. 11, in order that they
may act more efficiently upon the armature G.
It should be remarked, that the armature G is never allowed to come into actual
contact with the said pole pieces, the extent of the rocking of its arborg being
checked by small projections of brass (see the enlarged views Figs. 11 and 12).
Sheet II of the drawings illustrates my invention as applied to Street Fire
Alarms.
In this example, there are six transmitting instruments situated in different
streets or localities, or it may be in different rooms of a warehouse or other large
building. Each transmitter has a single stud for closing circuit and operating the
alarm on the receiving instrument at the Fire Engine Station, and for indicating
upon the dial, which bears the names of the transmitting stations from which
station the signal has been sent.
Fig. 13 is a diagram of the receiving instrument which contains the current
reverser. The main battery X, as well as the local gong battery Y, are also
situate at the receiving station, together with an auxiliary battery Y¹, and a key
for throwing the latter into action for the purpose to be presently explained.
Figs. 14. 15. 16. 17. 18 and 19 are diagrams of transmitters situate at different
points, which will be indicated on the dial of the receiver when an alarm is sent.
Figs. 20, 21 and 22 are plan, side, and front views of the transmitting instrument,
with the casing removed.
The transmitting instruments are electrically connected to the receiver by branch
wires from the main line wire, and are each in connection, through resistance coils,
with earth. The object of placing this resistance in the line wire is to allow only
a feeble current to pass from the battery, which will be insufficient to operate the
apparatus when not required, but will be sufficient to show on a galvanometer H,
the condition of the line wire.
Referring now to Figs. 20, 21 and 22, the stud A of the transmitter is operated
by a pull, instead of a push, and it is provided with ratchet teeth for keeping it in
a withdrawn position (see Fig. 21).-The withdrawal of the stud causes an inclined
surface a* on the shaft thereof, to bear upon the end of a vertical rod à¹*, which
thus depresses a spring catch a2*, and allows a contact spring a to come into
contact with a disc B.-This will have the effect of closing the circuit of the

page_text: battery X, through the electro magnets F F of the transmitting and receiving
instruments and the current reverser, as before described, and thereby causing an
álternating current to pass by the line 1, 1, and causing the disc B of the
transmitter, and the index needle of the receiver, to move round step by step, as in
the first described apparatus, until the insulating plug in the transmitter comes
under the contact spring a. The circuit through the spring a will thus be broken,
and the needle on the receiving instrument will stop; a closed circuit is however.
maintained through a spring b³, which remains in contact with the disc B, and
through a second electro magnet F¹ and a resistance coil F2, for the purpose of
returning the disc B and indicating needle, to their normal position, as will be
presently described..
The closing of the circuit rings the gong on the receiver, and excites the electro
magnets F, thereby rocking both the polarized armatures G, and rotating the
needle of the receiving instrument, and the disc B of the transmitter, until such
time as the insulating plug in the latter comes under the contact spring a.-The
position of the bearing point of the springs a of the several transmitters, in relation
to the insulating plug of the disc B, when in its normal position, is the same as
that of the radial springs b of the first arrangement.-It will thus be seen, that the
withdrawal of the stud A on a particular transmitter will set the apparatus in
action, and stop the indicating needle of the receiver opposite. the name of such
transmitting station, in the same way as the depression of one stud in the first
described arrangement will cause the needle to indicate the sign opposite to the
said stud.
I have said that the transmitters are each provided with a spring b¹ in permanent
contact with the disc B.-This spring 62 rests upon the insulating plug of the
disc B when the same is in its normal position. The return of the disc B to its
normal position, and of the indicating needle of the receiver to zero, is effected in
the following manner. When the insulating plug of the disc B breaks contact with
the spring a, the spring 6' remains in electrical contact with the disc B, but owing
to the current from the battery being compelled to pass through the coils F' and
resistance F, it is so weakened as to be incapable of working the apparatus.
When, however, the attendant at the receiving station wishes to return the parts
to their normal position, he depresses the key above mentioned, and switches into
action the auxiliary battery Y Y¹, thus providing sufficient additional power to
overcome the resistances F1 and F, and complete the rotation of the disc B.
Meanwhile the electro-magnet F¹ has been excited by the current passing around
its coils, and has withdrawn the spring arm a from contact with the disc B, in
which withdrawn position it is retained by the catch a** (see Fig. 21).
The depression of the key by the attendant, and consequent exciting of the
magnet F, operates a tell-tale arrangement, to show the person sending the alarm,
that the alarin has been received. The tell-tale consists of a plate pivotted behind
a circular opening in the face of the instrument (see Fig. 22), so as to be capable
of tipping, and showing two different colours or signs. This plate is held in its
raised position by a pin thereon resting upon the head of a vertical spring
armature situated near the electro magnet F¹-This armature is attracted by the
magnet F, when excited, and allows the plate to fall.
The return of the plate and stud A to their normal positions can be effected
mechanically by a key, as shewn, or electrical means may be devised.
.
It is obvious that my system of electrical signalling is capable of further
adaptation, for example to Synchronizing clocks and watchmen's tell-tales.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim is
1. In electrical telegraphing apparatus, the use of a current reverser constructed
substantially as above described with reference to the drawings, by means of which

page_text: a continuous electrical current may be converted into an alternating current, in the
manner set forth.
2. In electrical telegraphing apparatus, the means above described with reference
to the drawings, for reversing the direction of a continuous electric current,
whereby a prolonged contact is obtained at each reversal.
3. In electrical telegraphing apparatus, the means above described with reference
to the drawings, for interrupting the course of the electric current, for the purpose
of stopping the indicating needle as set forth.
4. In electrical telegraphing apparatus, constructing electro-magnets with polar
extension pieces, as shown and described with reference to the drawings, for the
purpose set forth.
5. In electrical telegraphing apparatus, the means above described with reference
to the drawings, whereby the apparatus is restored to its normal condition from
the receiving station.
6. In electrical telegraphing apparatus, the means above described with reference
to the drawings, whereby a current from a local battery is caused to ring a gong
for a limited time, substantially as set forth. .
7. The general construction and arrangement of electrical signalling apparatus,
substantially as shewn, and for the purpose described with reference to the
accompanying drawings.