IMPROVEMENTS IN TELEGRAPHIO APPARATUS FOR RAILWAYS
Year: 1879

page_text: LETTERS PATENT to Edward Tyer, of No. 4, Old Street, Finsbury, in the
County of Middlesex, for the Invention of "IMPROVEMENTS IN TELEGRAPHIO
APPARATUS FOR RAILWAYS."
Sealed the 29th August 1879, and dated the 26th June 1879.
PROVISIONAL SPECIFICATION left by the said Edward Tyer at the Offico
of the Commissioners of Patents on the 26th June 1879.
EDWARD TYER, of No. 4, Old Street, Fiusbury, in the County of Middlesex.
"IMPROVEMENTS IN TELEGRAPHIC APPARATUS FOR RAILWAYS."
My Invention relates to apparatus employed in railways for the purpose of
communicating from one part of a line to another, signals as to the arrival, departure,
or condition of trains, so as to guide the attendants in the working of the points
and signals under their charge. In great central stations or other situations where
numerous lines or branches meet, it is necessary for the attendants to know what
train may be approaching, or what may be its destination, and in order to apprise
them of this signalling instruments have been employed, shewing by the position of
an index on a dial the character or destination of an approaching train. The index
of such an instrument being moved step by step, as in alphabetical and printing
telegraph instruments, by means of a succession of electrical currents transmitted
from a distance, is sometimes liable to trip or fail to move over one or more divisions
owing to excessive rapidity or irregularity in the succession of the transmitted
currents, and false indications being thus given have led to serious risks in working
the traffic. The object of my Invention is to provide for such instruments means
of securing such slowness and regularity in the transmission of the operating
currents that the index shall not trip, but shall always be moved over the proper
number of divisions of the dial to give the signal intended. For this purpose I
provide at the transmitting instrument a dial having divisions marked in corre-
spondence with those of the receiving instrument. In each division there is a hole
to receive a peg, which the operator inserts when he desires to transmit a signal.
Having inserted the peg in the proper division, he pushes a plunger or key which is
in a convenient position on the side or face of tho instrument. This plunger or key

page_text: moves a pawl which turns a ratchet wheel partly round in opposition' to a spring.
The ratchet wheel is connected by gearing to an escapement and to a commutator,
and being caused to revolve by the spring, it moves the commutator at a slow and
regular rate, as determined by the escapement. By the movement of the commu-
tator a succession of electrical currents is transmitted to the distant station, the
number of such currents being determined by the position of the peg on the dial,
which stops tho escapement and commutator mechanism, when an arm connected
thereto reaches it, after having revolved through the proper number of divisions.
The travelling mechanism being thus stopped, the plunger or key is again free. The
currents transmitted as above described are at the distant station passed through
the coils of an electro-magnet, or through coils surrounding a polarised needle, cach
current causing in the one case the movement of an armaturo, or in the other case
the deflection of the needle. An arm attached to the armature or needle is thus
caused to oscillate once for each current between two crown wheels fixed face to
face on the axis of a signalling index, causing them to revolve step by step as many
teeth as there are currents transmitted, and thus bringing the signalling index round
to a division on the dial corresponding to that in which the peg had been inserted
in the transmitting instrument. When I employ a polarised needle in the receiving
instrument, I increase its power and delicacy in the following manner :-I make the
needle of soft iron fixed on a soft iron or steel spindle, which is mounted in centres.
Part of the spindle is enclosed, but can turn freely in an iron or steel tube projecting
from the pole or polar extension of a magnet, by which means the magnetism is
powerfully induced in the needle. This arrangement for inducing magnetism is
applicable generally to the signalling instruments used on railways, in which the
indications are given by deflections of a polarised needle. Although I have above
described a transmitting instrument, in which the insertion of a peg in a hole
determines the extent of movement of a commutator, and consequently the number
-of successive currents transmitted, it is obvious that instead of employing a remove-
able peg for this purpose, a key or button might be pressed-on, or a handle might
be turned round to the division of the dial at which the commutating mechanism
has to be stopped, and the movement of such key, button, or handle might be
arranged to wind up the escapement and commutator mechanism, thus dispensing
with the separate key or plunger for that purpose.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Edward Tyer in the Great Seal Patent Office on the 23rd
December 1879.
EDWARD TYER, of 4, Old Street, Finsbury, in the County of Middlesex.
PROVEMENTS IN TELEGRAPHIC APPARATUS FOR RAILWAYS."
"IM-,
My Invention relates to apparatus employed on railways for the purpose of com-
municating from one part of a line to another signals as to the arrival, departure, or
condition of trains, so as to guide the attendants in the working of the points and
signals under their charge. In great central stations and other situations where
numerous lines or branches meet it is necessary for the attendants to know what
train may be approaching, or what may be its destination, and in order to apprise
thein of this signalling instruments have been employed showing by the position of
an index on a dial the character or destination of an approaching train. The indox
of such an instrument being moved step by step, as in alphabetical and printing
telegraph instruments, by means of a succession of electrical currents transinitted
from a distance, is sometimes liable to trip or fail to move over one or more divisions
owing to excessive rapidity or irregularity in the succession of the transmitted
currents, and false indications being thus given have led to serious risks in working
the traffic. The object of my Invention is to provide for such instruments means
of securing such slowness and regularity in the transmission of the operating
currents that the index shall not trip, but shall always be moved over the proper
number of divisions of the dial to give the signal intended. For this purpose I
provide at the transmitting instrument a dial having divisions marked in corre-
spondence with those of the receiving instrument. In each division there is a hole
to receive a peg which the operator inserts when he desires to transmit a signal.
Having inserted the peg in the proper division he pushes a plunger or key which
is in a convenient position on the side or face of the instrument. This plunger or
key moves a pawl which turns a ratchet wheel partly round in opposition to a
spring. The ratchet wheel is connected by gearing to an escapement and to a com-
mutator, and being caused to revolve by the spring it moves the commutator at
a slow and regular rate, as determined by the escapement. By the movement of
the commutator a succession of electrical currents is transmitted to the distant
station, the number of such currents being determined by the position of the peg on
the dial, which stops the escapement and commutator mechanism when an arm
connected thereto reaches it after having revolved through the proper number of
divisions. The currents transmitted, as above described, are at the distant station
passed through the coils of an electro-magnet, or through coils surrounding a
polarised needle, each current causing in the one case the movement of an armature;
or in the other case the deflection of the needle. An arm attached to the armature
or needle is thus caused to oscillate once for each current between two crown wheels
fixed face to face on the axis of a signalling index, causing them to revolve step by
step as many teeth as there are currents transmitted, and thus bringing the
signalling index round to a division on the dial corresponding to that in which the
peg had been inserted in the transmitting instrument. When I employ a polarized
needle in the receiving instrument I increase its power and delicacy in the following
mauner-I make the needle of soft iron, fixed on a soft iron or steel spindle, which
is mounted in centres. Part of the spindle is enclosed, but can turn freely in an
iron or steel tube projecting from the pole or polar extension of a magnet, by which
means the magnetism is powerfully induced in the needle. This arrangement for
inducing magnetism is applicable generally to the signalling instruments used on
railways, in which the indications are given by deflections of a polarised needle.
Although I have above described a transmitting instrument, in which the insertion

page_text: of a peg in a note dctermmes the extent of movement of a como conse
quently the number of successive currents transmitted, it is obvious that instead of
employing a removeable peg for this purpose a key or button might be pressed on; or a
handle might be turned round to the division of the dial at which the commutating
mechanism has to be stopped, and the movement of such key, button, or handle
might be arranged to wind up the escapement and commutator mechanism, thus
dispensing with the separate key or plunger for that purpose.
DESCRIPTION OF THE DRAWINGS.
"
Fig. 1 represents a front view of a combined transmitting and receiving instru-
ment according to my Invention. The upper part A, which is the receiving part
of the instrument, presents a dial having in its divisions some of the signals usually
employed on railways, and an index which is made by electrical action from a
distant station to point to one or other of these divisions. The lower part B, which
is the transmitting part of the instrument, presents also a dial C, with corresponding
divisions, and opposite each division there is a hole, in any one of which the
operator can insert a peg D, which is for convenience chained to the instrument,
and when not in use is inserted in a socket on the case, as shewn in Fig. 1. At the
side of the instrument is a handle with a knob E, which the operator can press
down for the purpose of transmitting a signal in the following manner-Suppose
he desires to apprise the signal man at the distant station with which his instru-
ment is connected that a goods" train is entering, or is in the section of line
between the two stations, he inserts the peg D into the hole opposite the division
marked "goods" on the dial C, and he then depresses the handle E as far as he
can and lets it go. The transmitting instrument then begins to move in obedience
to mechanism which will presently be described, and the index of the receiving
instrument at the distant station moves gradually round till it stands opposite the
division marked "goods." It is of advantage to connect the receiving instruments
of both stations to the same line wires, so that when a certain signal is transmitted
from either the operator who transmits it sees the index of his own receiving instru-
ment move to it. In the highest division of the dial C there is a cross or other
zero mark indicating when it is visible that the transmitting mechanism is inert.
This mark is made upon a small screen c mounted behind an aperture in the dial,
which immediately on the transmitting mechanism beginning to move is shifted
aside, presenting at the aperture another mark, such as a red disc, indicating that a
signal is being transmitted or has been transmitted, but that the operation of the
transmitting mechanism is not completed. On the operator taking the peg D out
of the hole the receiving indices proceed to complete a revolution round their dials
until they finally stand at zero, and the red disc then gives place to the cross.
During the transmitting movement and the completion of the revolution of the
indices, the handle E gradually rises till it attains its original position ready to be
depressed again for the transmission of another signal when required. Such being
the mode of operating I will now describe the mechanism of the transmitting and
receiving portions, referring to the Figures which shew the internal construction of
one of these instruments as follows:-Fig. 2 is a front view of the instrument, with
the door on which is the transmitting dial folded back on its hinges so as to shew
the commutator behind it; Fig. 3 is a vertical section of the transmitting mechanism,
in which there is a train of toothed wheels and pinions indicated by dotted circles;
Fig. 4 is a vertical section of the transmitting mechanism on a plane at right angles
to its face; Fig. 5 is an elevation; and Fig. 6, a plan of the mechanism behind the
receiving dial.
The handle E is pivotted on the axis of a ratchet wheel F, with the teeth of
which engages a spring pawl f mounted on a wheel F¹ behind it. To the handle E
are attached a pair of helical springs e, the upper ends of which are attached to the
fixed framing. When the handle E is pushed down till it stops against a pin e'

page_text: theso springs are extended, and when the handle is let go they, by their elastic force,
raise the handle, and during its ascent the wheel Fl is turned by the pawlf partly
round through a definite fraction of a revolution, as, for example, one eighth thereof.
The wheel F, through multiplying gear, transmits motion to a flyer f¹, which
by resistance of the air to its rapid revolution moderates the speed of movement;
instead of a flyer an escapement may be employed for this purpose. The axis g
of one of the wheels of the train has on it a commutator G, the speeding of this to
the wheel F being such that G makes one complete revolution while F makes that
fraction of a revolution which is due to the stroke of the handle E. The commutator
G is of cylindrical form, consisting of two metal discs, each having blades projecting
from it, both discs fixed on insulating material, with their blades alternating on the
periphery of the cylinder. Contact springs g', g³, g³, bear respectively against the
back disc and the circumference of the commutator whilst the front disc is in
metallic connection with the instrument. The number of blades to each disc corre-
sponds with the number of divisions on the dial, and the contact points of the
springs g and g³ touch the periphery of the commutator at such points that while
the one is making contact with a blade of the back disc, and is therefore in commu-
nication with g³, the other is making contact with a blade of the front disc, and is
therefore in communication with earth. The contacts g³ and g³ being connected to
opposite battery poles while g¹ is connected to the line wire, the commutator G,
during its revolution or partial revolution, by means of its blades sends into line a
succession of positive and negative alternating impulses, determined by the number
of blades that pass the contacts g²; g³. An arm H fixed on the axis of the commu-
tator G revolves with it, and when this arm comes against the pin D inserted. in
one of the dial holes the commutator is stopped, after having turned through a part
of a complete revolution determined by the position of the pin D, and therefore,
after having sent a definite number of impulses into line and actuated thereby the
receiving instrument, as I will presently describe. The arm H is so shaped that
when it, by a complete revolution of the commutator, comes round to the position
shewn in Fig. 2, it has lifted a pin h on the screen c so as to keep the zero mark
presented on the dial, but as soon as the commutator begins to move in the direction
of the arrow, Fig. 2, the arm H, escaping the pin h, allows the screen c to drop so
as to present the red disc on the dial. The cominutator is held in its zero position,
as shown in Fig. 2, by a pin j intercepting an arm I fixed on the axis of the com-
mutator. The pin projects from a lever J, on the tail of which acts a stud e³
projecting froin the face of the ratchet wheel F. When the handle E is depressed
(as indicated by the dotted lines in Fig. 2) turning the ratchet wheel F partly round
the pin e lifts the lever J and raises the stop pin j from before the arm I, thus
releasing the commutator, which, when the handle E is let go, is caused to rotate by
the action of the springs e at a speed moderated by the flyer f¹, or escapement and
its train, until it is stopped by the peg D in one of the dial holes.
When the peg
is removed the commutator completes its revolution, returning to the position shewn
in Fig. 2, where it is again stopped by the pin j, the arm H having in reaching the
position shewn moved the pin h so as to raise the screen c, causing the withdrawal
of the red disc and the appearance of the zero mark. When the mechanism is in
this condition a contact spring g' is held up by the non-conducting arm of a lever K,
the tail of which rests on the handle E, and at the same time another contact spring
g rests on a pin projecting from the arm I, these contact springs g and g³ being
connected to the conductors so that in this condition a bell or other signalling
instrument may be worked from the circuit. But when the handle E is depressed,
allowing the tail of the lever K to descend, then the contact spring g' also descends
and makes contact, and when the commutator begins to move, withdrawing the pin
froin under the spring g³, and so breaking contact therewith, then the transmitter is
put in circuit ready for the transmission of the successive impulses to the receiver
at the distant station whilst the bell or other signalling instrument is cut out of
circuit. These impulses excite an electro-magnet MI so as alteanately to attract and

page_text: repel a polarized armature L, the end of which, working between two crown wheels
N fixed face to face on an axis n, causes them to move tooth by tooth. On the axis
n is fixed the index O, which is thus turned step by step round the receiving dial.
As the number of successive impulses transmitted is determined by the part of a
revolution at which the transmitting commutator is stopped by the peg D, and as
each impulse causes the index O to advance one step, it will be caused to take an
attitude on its dial corresponding to the position of the peg inserted in the trans-
mitting dial, and will therefore point to the same signal as that where the peg is
inserted. When the peg is removed, permitting the commutator to complete its
revolution, the index O is caused to complete its revolution and to rest at zero. Tho
polarization of the armature L is effected according to my Invention in the following
manner-It, as well as the axis on which it oscillates, is made of iron or steel, and
the axis is made of some length, enclosed within two loosely fitting steel or iron
tubes p, p, projecting from the ends of two permanent magnets P, P. Thus there is
induced on the armature L the same polarity as that of the ends of the magnets P, P.
This mode of inducing polarity is applicable also to polarized needle instruments
employed to give indications by the deflections of a needle. Fig. 7 is a side view,
Fig. 8 a back view, and Fig. 9 a plan of such an instrument. The index O is fixed
on the iron or steel axis, which carries an iron or steel plate or needle L, and is
continued into a loosely fitting iron or steel tube p projecting from the end of a
permanent magnet P. The needle L is free to oscillate in central slots within two
Hattened electro-magnets M, M, being attracted into the one or the other, according
to the direction of the current through their coils. A needle thus actuated may bo
employed to work a repeating signal as shewn in Fig. 10, or a block signal as in
Fig. 11. Compound or divided needles may be polarized in the manner above
described, as shewn in side view at Fig. 12 and front view at Fig. 13, where P is
the permanent magnet, having projecting from it a tube p enclosing the axis n of
two or more needles L to be acted on by the slotted poles of the electro magnet
M, M.
In this case each of the needles L is slit up some distance from its end, so as
to prevent it from forming a continuous armature connecting the poles of the
magnet. Fig. 14 is a front view, and Fig. 15 a side view of another form of
polarized armature suitable for working the semaphore arm of a repeating signal.
It consists of a light open frame of iron N fixed on the axis a of the semaphore L,
which axis passes through the frame near one side thereof. The lower face of the
frame is presented towards the poles M of the electro magnet, being attracted
towards the one or the other of these according as the magnet is excited by a + or -
current, and thereby causing the semaphore arm L to take a corresponding attitude.
The arm L which shews outside the dial is counterbalanced by an arm 7 inside.
The axis a of the armature is enclosed, as previously described, within an iron tube
projecting from a permanent magnet, whereby the armature is polarised. A vertical
cut is made in the frame constituting the armature, so as to prevent it, when it is in
a middle position, from operating as a continuous armature closing the magnetic
circuit of the poles of the electro magnet.
Having thus described the nature of my said Invention, and in what manner the
same is to be performed, I claim,-
First. The use for transmitting telegraphic railway signals of an apparatus in
which a commutator, caused to revolve with moderated speed until it is stopped by
a peg inserted in a hole in a dial, determines the transmission of alternating electrical
impulses proportioned in their number to the part of a revolution through which it
has moved, thereby causing a proportional movement of a receiving index at a
distant station, substantially as herein described.
Second. The use, in combination with the transmitting apparatus referred to in
the preceding claim, of a receiving apparatus in which a polarized armature, caused
to oscillate by the influence of the transmitted impulses on an electro magnet, gives
step by step movement to an index through a part of a revolution corresponding
with that through which the transmitting commutator is moved,

page_text: Third. The construction of transmitting and receiving apparatus herein described
with reference to Figs. 1 to 6 inclusive of the accompanying Drawings.
Fourth, Polarising an oscillating armature or needle by enclosing its axis within
a tube attached to the end of a permanent magnet, substantially as herein described.
In witness whereof, I, the said Edward Tyer, have hereunto set my hand and
seal, this Twenty third day of December, in the year of our Lord One
thousand eight hundred and seventy nine.
EDW. TYEK. (L.B.)