Improvements in Electrical Signalling Apparatus for Use upon Railways.
Year: 1895

page_text: Date of Application, 20th Mar., 1895
Complete Specification Left, 10th Oct., 1895-Accepted, 23rd Nov., 1895
Date of Application, aut mal, 1000
Complete Specification Left, 10th Oct., 1895-Accepted, 23rd Nov., 1895
PROVISIONAL SPECIFICATION.
Improvements in Electrical Signalling Apparatus for Use upon
Railways.
We, HENRY JAMES PRYCE, of 54, Filey Avenue, Clapton, Civil Engineer, and
LUIZ DE MORAES GOMES FERREIRA, of 36, Navarino Road, Hackney, Electrical
Engineer, both in the County of London, do hereby declare the nature of this
invention to be as follows:-
Our invention relates to electrical signalling apparatus for use upon railways
worked on the block system, and to that class of such apparatus used for
signalling from one signalman to another.
One part of our invention has for its object to ensure that a signalman in one
signal cabin shall not give a visual signal in another cabin without at the same
time giving an audible signal, and to this end we arrange in combination with the
ringing key of each instrument a locking device which is arranged in conjunction
with the commutator knob or handle, in such a manner that the ringing key must
be operated before the commutator handle, whereby an audible signal is given
before the visual signal. This locking device may consist of a pin fixed to an arm
on the shank of the ringing key and projecting through a disc moving with the
commutator knob or handle into one of a series of holes on a fixed disc, the said
holes corresponding with the various signals to be given, such as "Train on line,"
"Line clear," "Line closed."
Another part of our invention has for its object to improve the construction of
the commutator through the medium of which the electric currents are caused to
pass in one or other direction through the line according to the signal to be given,
whereby such commutators will be rendered more efficient in operation and durable
than heretofore. According to this part of our invention we provide a ring divided
into four sections two of which are connected to the battery and the other two to
"line" and "earth" respectively, and we provide an oscillating block adapted to
be operated by the commutator knob or handle and carrying two contact forks
bearing upon the sectional ring, and so arranged that by rotating the said blocks
relatively with the ring, in one or other direction, the positive pole of the battery
can be connected with "line or "earth" according to the signal given, the other
pole being simultaneously connected with "earth" or "line."
Another part of our invention has for its object to prevent injury to the contacts
for the bell circuit by sparking, and to this end the said contacts are made in the
form of pins having rounded ends and arranged in connection with contacts
springs in such a manner that the actual contact takes place at the sides of the
rounded heads leaving the ends of the said pins, which are the operative contact
pointe, uninjured.
Another part of our invention has for its object to provide a greater range of
movement for the needles of needle instruments and to provide for such needles
being held more steadily in the neutral position thereby preventing the liability of
the signals being mistaken.
In carrying out this part of our invention we attach to the needle arbor a
divided cylindrical armature, the two parts of which are magnetic or which may be
of soft iron, and arranged between the poles of a permanent or electro magnet so
that magnetism is induced in them in a manner that the tendency of the magnetism

page_text: will always be to retain the needle in its neutral position. The electro magnets
for moving the armature from its neutral position have their poles arranged at
right angles to the poles of the inducing magnet (when used) and are of such
strength that when energized they shall act upon the divided armature, thereby
operating the needle, which, owing to the magnetization of the two parts of the
armature, is caused to move through an angle of about 45 degrees from its neutral
position on one side or the other according to the direction of the current.
In order that any residual magnetism of the electro magnets shall not counteract
the influence of the inducing magnet in returning the needle to its neutral position,
each part of the drum armature is made narrower at its central portion than at the
ends so that a smaller area is exposed to the action of the poles of the electro
magnet than to the poles of the inducing magnet.
In cases where it is desirable to use a bar armature, instead of a cylindrical
armature as herein before described, we form the inducing magnet, arranged in
conjunction with the said needle, so that its two poles are opposite to the two ends
of the said armature in its neutral position, and we make the solenoid coils some-
what of a fan-shape, that is to say, so that the windings, instead of being parallel
with the armature when in its neutral position, are made more or less divergent.
When our improvements are applied to what is known as a three wire block
instrument for use upon single roads or at junctions, we advantageously arrange a
locking device between the up and down instruments of a cabin in order to prevent
signals being given for up and down trains or train approaching on converging
lines at the same time. With this arrangement we advantageously make use of a
commutator divided into six sections.
Dated this 20th day of March 1895.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicants.
Improvements in Electrical Signalling Apparatus for Use upon
Railways.
We, HENRY JAMES PRYCE, of 54, Filey Avenue, Clapton, Civil Engineer, and
LUIZ DE MORAES GOMES FERREIRA, of 36, Navarino Road, Hackney, Electrical
Engineer, both in the County of London, 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 :-
Our invention relates to electrical signalling apparatus for use upon railways
worked on the block system, and to that class of such apparatus used for signalling
from one sigualman to another, the objects of the invention being-
(1) To ensure that a signalman in one signal cabin shall not give a visual signal
in another cabin without at the same time giving an audible signal :
(2) To improve the construction of the commutator through the medium of
which the electric currents are caused to pass in one or other direction through the
line according to the signal to be given, whereby such commutators will be rendered
more efficient in operation and durable than heretofore:
(3) To prevent injury to the contacts for the bell circuit by sparking:
(4) To provide a greater range of movement for the needles, semaphores or
other indicators of instruments and to provide for such needles or indicators being
held steadily in the neutral position thereby preventing the liability of the signals
being mistaken; and,
(5) To provide means whereby, when our improvements are applied to what is
known as a three wire block instrument for use upon single roads or at junctions, a

page_text: locking device between the up and down instruments of a cabin shall operate in
order to prevent signals being given for up and down trains, or trains approaching
on converging lines, at the same time.
In the accompanying drawings ;-
Figure 1 is an elevation of an instrument having some of our improvements
applied thereto :
Figure 2 is a section on the line 2-2, Figure 1, part of the case of the instrument
being removed :
Figure 3 is an elevation of the mechanism of the instrument, the door of the
casing being thrown back to shew the parts on the inner side of the same, and the
front plate of the apparatus removed:
Figures 3 to 19 are views hereinafter described.
Similar letters of reference indicate corresponding parts in the several figures.
a is the case of the instrument, 6 the commutator, the commutator knob which
is fixed to a spindle & carried in a bushing fixed to the door in the front of the
case, and c is a hub fixed on the spindle b² and having a slotted arm e¹ which engages
with a pin c on the movable part 6 of the commutator so that when the said spindle
is rotated by the knob the commutator part 63 which is made of insulating
material will also be partially rotated in a well known manner. d is an indicator
plate which is also fixed to or formed in one piece with the hub c and moves in
iront of an aperture d' in the casing, the said indicator having marked upon it the
various signals to be giver such as "Train on line," "Line clear" and "Line closed."
e is the ringing key the stem of which slides through the spindle 62 and bears
with its rear end against the contact lever e¹ for the bell, a spring e² surrounding
the stem within the spindle serving to normally press the key outwards.
In order to prevent the commutator being moved without ringing the bell, the
said stem of the ringing key is provided on its inner end with an arm ³ carrying a
pin e which projects through suitable openings in the hub c into a locking-plate e
fixed to the inner side of the door, the said locking plate having in it a number of
holes e, e, shewn in Figure 3, the positions of which correspond with the different
positions of the indicator plate d. The length of movement necessary to disengage
the pin e¹ from the locking plate is more than that which it is necessary to give to
the contact lever to make the desired contact, so that in order to move the
commutator 6 to operate the visual signal of an instrument in another box it will
be obvious that it is first necessary to give an audible signal.
e is the contact in the bell circuit of the instrument, and e8, 8 are the contacts
in the sending out battery circuit for ringing the bell.
In order to ensure that when the indicator d is moved to one of its positions the
pin e shall be immediately opposite the hole e corresponding with this position, we
arrange the spring lever shewn in Figure 3, which lever is provided with three
notches or recesses at f¹ operating in conjunction with a pin f* on the hub c.
The construction of the commutator will be readily understood by reference to
Figure 4 which is a plan view of the said commutator. This commutator comprises
a ring divided into four sections g, g, h, h', the two former sections being connected
with the two poles of a battery and the two sections h, respectively to earth and
to line in a manner which will be readily understood by reference to Figure 5
which is a diagram shewing the arrangement of the electrical connections between
two instruments and in which i, i indicate the batteries to which the sections g, g¹
are connected, i¹, the wires connecting the sections h,h to the earth and ², 2 wires
connecting the commutator sections ', ' to tell-tale indicator magnets j, j k kare
the magnets for operating the indicator which receives the signals from the distant
signal box and and I are the indicator line wires between two instruments.
m is the bell circuit and m', m³ the batteries for ringing the bells which are
indicated by m³, m³. n, n' are the insulated contact forks of the movable part of
the commutator, which forks are designed respectively to place the sections g, and g'
in electrical connection with the section h, or with the section .
The general operation of the apparatus will be readily understood by referring

page_text: to Figure 5 in which the letters A and B are used to indicate two instruments.
Assume the commutators of both instruments to be in the position shewn in Figure 4,
that is to say, with the forks n, n' in contact with the sections h, which correspond
with the position "Line closed on the indicator. If now the operator of instrument A
desires to call the attention of the operator of instrument B he moves the ringing
key e to make contact between the lever e¹ and the contacts es, the result of which
is that a current flows from the battery m¹ of instrument A through the contact
lever and the line m to the contact e of instrument B and through the bell m³
thereof to earth. If the operator at B then desires to give the signal, say "Line
clear," he moves the commutator of bis instrument to the position indicated, that is
to say, into the position to place the sections h, g' in contact and the sections ³, g
in contact; the current from the battery i of instrument B then flows through the
section 9, the fork n' the section ¹ thence to the magnet coils j, j and the line ³
and then through the coils of the magnets k, k of the indicator of instrument A
flowing finally through earth to the wire i¹ the section h, fork n and section g' back
to the battery i. If on the other hand it is desired to indicate "Train on line" the
commutator is moved so that the plates g and h are placed in connection and the
plates h', g are placed in connection whereby the current is caused to flow through
the circuit last described but in a reverse direction.
It will be obvious that if the signalman at A desires to transmit the signals
"Line clear" or "Train on line to the signalman at B, the current from the battery i
of instrument A will flow through the coils j, j through the line to the coils k, k
of instrument B and thence through the earth back to instrument A or in the
reverse direction.
To prevent injury to the contacts e, e8 of the bell circuit by sparking, contact
pins e, e are arranged on the contact lever e¹ and made with rounded ends and the
contact springs are also rounded in a manner which will be readily understood by
reference to Figures 6 and 7 (which are diagrammatic views of a portion of the
contact lever and one spring in different positions) so that the actual contact takes
place at the sides of the rounded ends, as shewn in Figure 6, leaving the ends
of the said pins, which are the operative contact points as shown in Figure 7,
uninjured.
In carrying out that part of our invention which relates to the provision of
means whereby a greater range of movement for the needles of needle instruments
is provided for and whereby such needles are held more steadily in the neutral
position than heretofore, we attach to the needle arbor o of each pair of
magnets j, j, k, k a divided cylindrical armature the two parts of which are of soft
iron and which are arranged between the poles of a magnet (hereinafter termed an
inducing magnet) as well as between the pole pieces of the ordinary electro-magnets.
Figure 3 (which is an elevation of the rear side of the plate p shewn in Figure 2
and which is represented as being removed from the apparatus in Figure 3) shew's
the arrangement of permanent inducing magnets (which are indicated by the
letters 9,
and their pole pieces by the letters q', q') in combination with the
cylindrical divided armatures which are indicated by the letters r, r. The pole
pieces q', q' are arranged at right angles to the pole pieces of the ordinary electro-
inagnets as shewn in Figures 8, 9 and 10 which are respectively an elevation, a
plan and a vertical section of one of the armatures drawn to an enlarged scale.
With this arrangement if the upper pole piece g¹, Figure 8, of the inducing magnet
be of north polarity and the lower of south polarity, the upper adjacent edges of
the two sections of the armature will have magnetism of south polarity induced in
them and the lower edges magnetism of north polarity. Assuming now the right
hand pole piece of the electro-magnet to be of north polarity and the left hand pole
piece of south polarity, the cylindrical armature will be caused to rotate in the
direction of the arrow 1, Figure 8, whereas if the polarity of the two pole pieces be
reversed the armature will be caused to rotate in the reverse direction, the amount 5
of movement obtained being greater than that which can be obtained by a bar-
armature and solenoids. When no current is flowing through the ordinary magnets

page_text: the permanent magnet will tend to retain the cylindrical armature in its vertical
position which corresponds with the position "Line closed on the indicator.
It will be obvious that instead of using permanent inducing magnets we may
use electro-magnets in the manner herein before described.
In order that any residual magnetism of the main or ordinary electro-magnets
shall not counteract the influence of the inducing magnets in returning the needle
to its neutral position, each part of the drum armature is preferably made narrower
at its central portion than at the ends, as clearly shewn in Figures 9 and 10, so
that a smaller area is exposed to the poles of the said electro-magnet than to the
poles of the inducing magnet.
Instead of using inducing magnets and armatures of soft iron, we may dispense
with the inducing magnets and employ divided magnetized armatures whereby
approximately the same result as that hereinbefore described is obtained. Or,
instead of using a cylindrical armature, we may use an armature of the kind shewn
in Figure 11, or of the kind shewn in Figure 12; in both these forms of armature
a greater mass of metal is arranged opposite to the inducing magnets than opposite
to the poles of the main magnets.
In cases where it is desirable to use a bar armature instead of a cylindrical
armature or an armature of the kind shewn in Figures 11 or 12, we form the
inducing magnet, arranged in conjunction with the indicator needle, so that its
two poles are opposite to the two ends of the said armature in its neutral position,
and we make the solenoid coils somewhat of a fan-shape, that is to say, so that
the windings, instead of being parallel with the armature when in its neutral
position, are more or less divergent. This arrangement is shewn in Figures 13
and 14 (which are respectively an elevation and side view): in these figures q is the
inducing magnet, q' are the pole pieces thereof, q, q' are the fan-shaped solenoid
coils, and is the bar armature.
In order to adapt our invention for use upon single lines or at junctions, we
provide the arrangement shewn in Figures 15 to 18, Figure 15 being a view
shewing the modifications necessary in the commutator, Figure 16 an elevation of
the mechanism on the inner side of the case door, similar to that shewn in Figure 3,
Figure 17 a plan of this mechanism and Figure 18 a diagram shewing the
arrangement of the circuits.
In carrying out this part of our invention as applied for use upon a single
line we arrange in each instrument an electro-magnet which is energized by the
current of another instrument, the said magnet being adapted to lock through the
medium of its armature a notched disc on the spindle 2 of the commutator knob.
In Figure 16 s indicates this electro-magnet, s the armature thereof, t the notched
disc upon the spindle and t' the lever which engages with the notch in the said
disc, the said lever being acted upon by the armature in such a manner that,
when the magnets is energized, the armature will draw the lever into engagement
with the said notch. u is a spring which normally tends to hold the lever t¹ out
of engagement with the said notch.
The construction of the commutator is modified by inserting between the
section and the sections g, gl supplementary sections v, v', the fork n¹ of the
commutator being arranged so that, when in the "Line closed" position, it will
lie upon the said sections v, v¹ which are in the circuit of the indicators of the
other instrument and of the locking magnet S. When the commutator is iu
this position the notch of the disc t is in the proper position for the engagement
of the levert therewith.
The arrangement of the circuits will be readily understood by reference to
Figure 18 in which A indicates, say, the up road instrument and B the down road
instrument in a signal box.
Assume now the signalman in box X, Figure 18ª, gives "Line clear" to a
signalman in box Y for an up train, the electric current flows as follows, in order
to lock the instrument B in box X to prevent the signalman therein from giving
a signal at the same time for a down train to approach his box from box Z, that is

page_text: to say, the current from the battery i of instrument A flows through the
commutator section g, the fork n' and the section h¹ through the coils k, k thence
to the wire w of instrument B, through the section v', fork n¹, section v,
whence it flows through the magnets to the line which conducts it to the
instrument in box Y through which it flows back to instrument A by means of
the earth connections whereby as the magnets of the instrument B is energized
the armature s¹ will be drawn down to lock the commutator disc t and consequently
prevent the operation of instrument B until instrument A is again placed in the
"Line closed" position. The same remarks apply to instrument B, that is to say,
if a signal "Line clear" is given on the down line instrument B the up line
instrument A is locked.
When the apparatus is arranged at a junction, the operation of, say, the up
main instrument is arranged to lock the up branch instrument, that is to say, the
signal "Line clear" from the box X to the box Y, Figure 18B, serves to prevent
signal "Line clear" being given from box X to box Z on the branch line.
The magnet S may be worked as a shunt circuit instead of being in series with
the indicators.
In
Although in the foregoing description we have described our invention as being
applied to an instrument wherein the ringing key works through the commutator
knob, it is to be understood that our invention is also applicable to instruments in
which a ringing key independent of the commutator is employed. An arrangement
suitable for this purpose is shewn in Figure 19 which is a sectional elevation.
this modification the ringing key et has an extension formed upon it which
engages with one or the other of a series of notches y in a disc z on the spindle
of the commutator knob, whereby before the commutator knob can be turned it
is necessary to operate the ringing key e¹ to disengage the locking extension a from
the disc thereby ensuring that an audible signal as well as a visual signal shall be
given.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is :-
1. In electrical signalling apparatus, the combination with the commutator of
a locking device operated by the ringing key and so arranged that the commutator
cannot be moved without operating the ringing key substantially as, and for the
purposes, described.
2. In an electrical signalling apparatus the combination with the commutator of
a locking device arranged in conjunction with the ringing key, substantially as
herein before described and illustrated in Figures 2 and 3 and in Figure 19 of the
accompanying drawings.
3. In electrical signalling apparatus, a commutator constructed, arranged and
operating substantially as herein before described and illustrated in the accom-
panying drawings.
4. In electrical signalling apparatus, forming the contacts for the ringing key
with rounded ends substantially as herein before described and illustrated in
Figures 6 and 7 of the accompanying drawings.
5. In electrical signalling apparatus the use of a cylindrical divided armature
of soft iron and an inducing magnet, the parts of the said divided armature
opposite to the main or operating magnets being preferably of less width than
those opposite the inducing magnets, substantially as described for the purpose
specified.
6. In electrical signalling apparatus the combination with the needle or other
indicator of a divided armature which is magnetized, substantially as described
with reference to Figures 8, 9 and 10 and Figures 11 and 12 and for the purpose
specified.
7. In electrical signalling apparatus wherein the movements of the indicator
needle are controlled by a bar-armature and solenoid coils, winding the said solenoid

page_text: coils in a fan-shape, substantially as described with reference to Figures 13 and 14
for the purpose specified.
8. In electrical signalling apparatus wherein a bar-armature and solenoid coils
are employed, the combination with the said armature of a permanent magnet,
substantially as hereinbefore described.
9. In electrical signalling apparatus, the arrangement of an electro-magnet and
an arinature adapted to lock the commutator of the instrument, the said electro-
magnet being designed to be included in the circuit of another instrument,
substantially as described.
10. The improved apparatus for electrically signalling consisting of the parts
constructed and combined substantially in the manner hereinbefore described and
illustrated in the accompanying drawings and operating as, and for the purposes,
set forth.
Dated the 10th of Onkohan 1005
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicants.