Improvements in Electrical Apparatus for Controlling Traffic on Single Lines of Railway
Year: 1894

page_text: Date of Application, 1st Jan., 1894
Complete Specification Left, 1st Nov., 1894-Accepted, 8th Dec., 1894
PROVISIONAL SPECIFICATION.
Improvements in Electrical Apparatus for Controlling Traffic on
Single Lines of Railway.
We, WILLIAM ROBERT SYKES Junior, of 43 Kent House Road, Beckenham,
in the County of Kent, Telegraph Engineer, and ARTHUR GEORGE EVANS, of
116 Palace Chambers, Bridge Street, Westminster, in the County of Middlesex,
Civil Engineer, do hereby declare the nature of this invention to be as follows:-
The objects of our invention are to electrically control traffic on single lines of
railway so that one or more trains may proceed, say from A to B, in succession,
the second and succeeding trains not being delayed for the arrival of the first
at B; on the other hand, although a succession of trains may proceed from A
to B no train can proceed from B to A until the last train despatched from A has
arrived at B and the visual signal or staff or its equivalent, which the driver
carries, is inserted in its proper place in the staff instrument at B.
We arrange at each station, A and B for example, an instrument which is
designed to contain the specified number required of staffs or visual authorities
according to the largest number of trains which would be sent in one direction,
without any return trains from the other direction.
For the purpose of explanation we will assume that each instrument is supplied
with six staffs so that if six trains are sent from A there would be twelve holes in
the instrument at B, six to receive the six additional staffs sent from A. in
addition to the six already provided; it will thus be possible to send twelve trains
from B to A.
We arrange that, assuming the instruments to be normal and A desires to send
a train to B, A is inoperative and cannot send a train to B unless sanction is given
by B, B gives his sanction by moving a central switch in his instrument to the
releasing position and plunges his releasing plunger, the act of plunging the
releasing plunger operates a spring which makes an electric contact and indicates
at B that permission has been given A for the withdrawal of one staff; when this
movement is performed a current is sent along the line wire from B to A and A
having moved his releasing magnet over the staff he wishes to release, we will take
for example No. 1 staff, the current travelling in the direction of A energizes the
magnet over No. 1 staff, the pawl acting upon the staff which is provided with
teeth on its upper side is attracted to the magnet and the staff is ready to be
withdrawn, in the act of withdrawing the staff a lower tooth or projection depresses
a spring which breaks the line circuit between A and B and the galvanometers in
both instruments return to zero.
Starting signals are normally locked and are only released by the action of
withdrawing a staff, as follows:-
The lower projection of the staff, before mentioned, passes over an arm connected
to a shaft which runs the entire length of the instrument, connected to this arm is
a bar or link which operates in a square notch of the tappet connected to the
respective lever in the interlocking frame which is required to be interlocked, in
this case the starting signal lever; the act of withdrawing the staff withdraws
the bar or obstruction free of the tappet and allows the starting signal to be
moved. The current along the line wire from A to B goes through a contact so
that the starting signal lever at A must be in its normal position or "danger" for
the current to be free to travel to A's releasing magnet and the action of pulling
over the starting signal lever breaks down the circuit between A and B preventing B
releasing A to send a train to B, and upon the arrival of, say the first staff, at B,

page_text: and its insertion in the instrument the lower pawl acts upon the toothed wheel and
the wheel is revolved one tooth, putting it back, as far as the present description
goes, from "1" to zero.
Assuming that a staff is withdrawn from A. and for certain reasons it is found
desirable not to despatch the train to B but to take a train from B to A, the staff
should be reinserted in A's instrument and the act of reinserting it sends a current
to B which actuates a magnet and an armature, a pawl is connected to the latter
which revolves the toothed wheel one degree and sends the authority back
from "I" to "0."
When A plunges to B, it is of course desirable that B should not be able to
plunge to A; the act of A plunging to B revolves a disc which breaks down the
circuit from B to A as far as the releasing current of A to B is concerned.
In cases where A & B are some distance apart we find it convenient to utilize
relays together with a local circuit in connection with the releasing magnet. It is
obvious also that in some cases we may find it convenient to utilize relays in the
circuit of the magnet which actuates the toothed wheel as described above.
Dated this 1st day of January 1894.
JOHN P. O'DONNELL,
70 and 71, Palace Chambers, Bridge Street, Westminster, S. W..
Agent for the said Applicants.
COMPLEIE SIMULETUATION
Improvements in Electrical Apparatus for Controlling Traffic on
Single Lines of Railway.
We,
WILLIAM ROBERT SYKES Junior, of 13 Kent House Road, Beckenham
in the County of Kent, Telegraph Engineer, and ARTHUR GEORGE EVANS, of
116 Palace Chambers, Bridge Street, Westminster, in the County of Middlesex,
Civil 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 objects of our invention are to electrically control traffic on single lines of
railway so that more than one train may proceed, say from A to B, in succession,
the second and succeeding trains not being delayed for the arrival of the first
at B; on the other hand, although a succession of trains may proceed from A to B
no train can proceed from B to A until the last train despatched from A has arrived
at B and the visual signal or staff, or its equivalent, which the driver carries, is
inserted in its proper place in the staff instrument at B.
We arrange at each station, A and B for example, an instrument which is
designed to contain the specified number required of staffs or visual authorities
according to the largest number of trains which would be sent in one direction,
without any return trains from the other direction.
For the purposes of explanation we will assume that each instrument is supplied
with six staffs so that if six trains are sent from A there would be twelve holes in
the instrument at B, six to receive the six additional staffs sent from A in addition
to the six already provided; it will thus be possible to send twelve trains
from B to A.
We arrange that, assuming the instruments to be normal and A desires to send
a train to B, A is inoperative and cannot send a train to B unless sanction is given
by B B gives his sanction by operating his releasing plunger by which action a
spring makes an electric contact and a current is sent along the line wire from B
to A and A having moved his releasing magnet over the staff he wishes to release,
we will take for example No. 1 staff, the current travelling in the direction of A
energizes the magnet over No. 1 staff, the pawl acting upon the staff which is

page_text: provided with teeth on its upper side is attracted to the magnet and the staff is
ready to be withdrawn; in the act of withdrawing the staff a lower tooth or
projection depresses a spring which breaks the line circuit between A and B and
Further, when A has
the galvanometers in both instruments return to zero.
withdrawn the staff the index at B moves from "0" to "1" indicating that No. 1
staff is withdrawn at A.
Although we have shown on the drawings galvanometers yet it is obvious that
these may be dispensed with as their only duty is to inform the operator whether
the circuit is broken down or not.
Starting signals are normally locked and are only released by the action of
withdrawing a staff, as follows:-
The lower projection of the staff, before mentioned, passes over an arm connected
to a shaft which runs the entire length of the instrument, connected to this arm
is a bar or link which operates in a hole in the tappet connected to the respective
lever in the interlocking frame which is required to be interlocked, in this case
the starting signal lever; the act of withdrawing the staff withdraws the bar or
obstruction free of the tappet and allows the starting signal to be moved. The
current along the line wire from A to B goes through a contact so that the starting
signal lever at A must be in its normal position, or danger," for the current to be
free to travel to A's releasing magnet and the action of pulling over the starting
signal lever breaks down the circuit between A and B preventing B releasing A a
second time to send a train to B, and upon the arrival of, say the first staff, at B,
and its insertion in the instrument the lower pawl acts upon the toothed wheel and
the wheel is revolved one tooth, putting it back, so far as the present description
goes, from "I" to "0."
16
Assuming that a staff is withdrawn from A and for certain reasons it is found
desirable not to despatch the train to B but to take a train from B to A, the staff
should be reinserted in A's instrument and the act of reinserting it sends a current
to B which actuates a magnet and an armature, a pawl is connected to the latter
which revolves the toothed wheel one degree and sends the authority back
from "1" to "0."
When A. plunges to B it is of course desirable that B should not be able to
plunge to A; the act of A plunging to B revolves a disc which breaks down the
circuit from B to A as far as the releasing current of B to A is concerned.
In cases where A and B are some distance apart we find it convenient to utilize
relays together with a local circuit in connection with the releasing magnet. It is
obvious also that in some cases we may find it convenient to utilize relays in the
circuit of the magnet which actuates the toothed wheel as described above.
In order that our invention may be better understood and more readily carried
into effect we will proceed to describe the drawings hereunto annexed.
Figure 1 represents an exterior front view of our apparatus, say at section A ;
a similar complete apparatus would be fixed at section B.
Figure 2 is a sectional front view showing more clearly the circuits.
Below Figure 2 are shown, on the left hand a separate plan view of the polarized
relay and to the right hand a separate plan view of the bell plunger. The circuits
in this figure, for the purposes of understanding, are shown through the relay and
the plunger beneath the vertical view, Fig. 2.
Figure 3 is a cross section of Figures 1 and 2 showing a side view of the various
details.
Figure 4 is an enlarged view of the frame carrying the mechanism of the toothed
wheel and operating parts connected therewith.
Figure 5 is a side view of the movable magnet.
Figure 6 is a diagrammatic view of the working parts showing the electrical
circuits between the two sections A and B.
Figure 7 is a front view and Figure 8 an end view of the staff.
The same numbers refer to the same parts in the several figures of the drawings.
1 is the front of the case of the instrument, is the index for indicating the

page_text: number of staffs withdrawn from the other instrument, 3 is the plunger for giving
permission for the withdrawal of the staffs in the instrument at the other end of
the section, 4 is the bell plunger for giving bell signals for asking for permissions,
5 are openings for the withdrawal or insertion of the several staffs, 6 is the handle
connected to the movable magnet, 7 is a galvanometer, 8 is the line wire from, say
cabin B (assuming that the instrument we are now describing is at cabin A)
connected to spring 9; 10 is a spring normally connected to 9, 11 is a spring
adjacent to 9 connected to the battery 12, wire 13 goes to earth 14, 15 is the line
circuit from spring 10 to contact spring 16, contact spring 16 is normally in
connection with contact 17, 18 is a wire connecting contact 17 with the spring 19,
20 is insulation on spring 19, 21 is the contact from the spring 19 to the plate 22,
4 is the bell plunger, 24 is a spring leading to battery 25 and thence to earth 26,
27 is a wire from plate 22 making a junction at point 28 with wire 29, from the
point 28 to the right the wire goes through the polarized relay 30, through wire 31
to earth 32. Wire 29 goes through magnet 33 returns by wire 34 to earth 32;
35, 36, are contact pieces of polarized relay and 37 is a piece connected with the
tongue 38, 39 are magnets maintaining the tongue 38 in the central position. 40 is
a wire connected to contact piece 36 leading to contact spring 41, 42 is a button
on spring 41 fitting into a corresponding groove or recess 43 in the ebonite
wheel 44. The spring 41 is normally in contact when the indicator is at "0,"
that is, when spring 41 is normal it is in electrical connection with contact
piece 45; a wire 46 goes from contact piece 45 through the releasing magnets 47
and from thence through the battery 48 to piece 37 and tongue 38; a wire 49 goes
from contact piece 35 through bell 50, through battery 48 and wire 46 to the
tongue 38. 51 is a lever immediately behind the permissive plunger 3, fulcrumed
at 52 and connected to bar 53; a spring 54 normally in compression tends to
push 53 back into the position shown; 55 is a bevelled piece fixed to bar 53 acting
to operate blade 56 when the plunger 3 is moved and bar 53 moved towards the
front of the apparatus; 56 is connected to a lever 57 by a bar 58; a pin 59 is
fixed to lever 57; the armature 60 of the magnet 33 is attached to lever 61, 62 is
a pin fixed to lever 61, 63 and 64 are adjustable springs keeping levers 57 and 61
in position; 65 is a star-wheel fixed to spindle 66, upon the same spindle are the
wheels 67 and 68; the two ratchet wheels are placed with their teeth in opposite
directions; 69 is a dial fixed to spindle 66 and upon which the numbers "0"
to "12" are written; 70 is a magnet whose pole pieces extend to 71 and which
holds armature piece 72 when pressed down by the piece 55; 73 is a rod upon the
upper portion of which is fixed a piece 74 which piece overhangs the pin 62; at
the lower end of the rod 73 is fixed a pin 75 the extreme end of the rod working
in a bearing 76, over the pin 75 is a spring 77 attached to the piece 78, one end
of 78 working in a bearing 79 and the other end working about a centre pin 80
which pin is fixed to a rocking bar 81; the rocking bar is kept in the position
shown by a spring 90. Upon the rocking bar 81 is fixed a piece of ebonite 82 the
normal position of which is midway between the springs 9 and 10; a crank 83 is
fixed to rocking bar 81, attached to crank 83 is the downright rod 84 the end of
which pierces tappet 85 on starting signal lever 86; the trough 87 has a cover 88
with a hole through which the rod 84 passes securing lever 86 in the normal
position; the tappet 85 is bent over at its extreme end 89. 47 (Fig. 5) is a pair
of magnets attached to a casting 92; 93 and 94 are round bars extending the
whole length of the instrument case, upon which casting 92 and magnet 47 travel,
for the freer working of same a roller 95 is provided which roller works or travels
upon the edge of the angle-iron 96; immediately below the maguet 47 is a pawl 97
working about a centre 98, the pawl 97 prevents the withdrawal of staff 99 (see
Fig. 7 enlarged view); the staff has upon its upper edge a number of teeth over
which the pawl 97 passes when the staff is put into the instrument and which
prevent its withdrawal except when the pawl 97 is raised; a handle 6 is attached
to casting 92 in order to move the magnet 47 over the desired staff. On the lower
edge of the staff is a projection 101 which engages with rocking bar 81 and moves

page_text: it from left to right upon its withdrawal and in the putting back of the staff in
the reverse direction.
The action of our invention is as follows:-
Assuming the instrument to be normal, starting signals in their normal or
"danger" position & the staff's in the instruments and that a train has to be sent
from A to B; A, normally, is not free to withdraw a staff; A first calls up on the
bell and asks that sanction be given him, B replies by the same signal (this,
however, has no particular reference to our invention as it is usual with ordinary
train signalling); A having asked permission, B plunges or presses in plunger 3
which operates blade 51 and bar 53, the bevel portion of the block 55 travelling
inwards moves down the blade 56 which in its turn operates 58 and pin 59, by this
action the pin 59 travels down on the teeth of the toothed wheel 67 revolving the
latter from left to right; although this wheel is revolved it is not sufficient to move
the dial 2, Fig. 1, its full movement sufficient to change it from "0" to "1."
When the blade 58 is depressed by 55 so that the pin on blade 58 engages with the
bottom teeth of the wheel 67 the top cross blade 57 makes contact between spring 16
and contact piece 16ª, Fig. 2, which latter energizes the magnet 70 and attracts
the armature 72 on blade 58 to itself; thus the operator at B is prevented from
giving a second sanction or doing anything other than moving the plunger.
B having given sanction to A, A now desires to withdraw a staff; if the movable
magnet operated by handle 6 happens to be over the staff he wishes to withdraw
then A is free to withdraw said staff, but if the magnet is not over the staff he
wishes to withdraw he moves the magnet along the rods 93 and 94 until he gets it
immediately above the staff he wishes to withdraw, when the handle is free to be
allowed to rest in the notch opposite the opening for the said staff; (it should be
understood that immediately B has given sanction to A that the magnet is then
energized and is free to allow the withdrawal of any staff), the magnets 47 being
energized raise the pawl 97 free of the teeth on the upper edge of the staff thereby
allowing the withdrawal of the latter. In the act of withdrawing the staff at A
the projection 101 operates the rocking shaft 81 moving it from the central normal
position to the right; the ebonite piece 82 being fixed to the rocking bar 81 in its
movement raises the spring 10 disconnecting the junction piece with 9, the
disconnection thus made breaks down temporarily the circuit between A and B.
The current is restored between A and B when the rocking shaft 81 resumes its
normal position after the withdrawal of the staff, and contact between springs 9
and 10 is remade. After the piece 101 has moved clear of the rocking shaft 81
the rocking shaft resumes its normal position and 9 and 10 resume contact. The
armature 72 in B's instrument falls away from pole pieces 71, the pin 59 is
disengaged from the toothed wheel 67; the block 65ª falling by gravity on the
wheel 65 completes the movement of that wheel, which is on the same spindle as
the other wheels, until the block occupies the whole of the space between two of
the teeth of the star-wheel, this latter movement completes the movement of the
indicator from "0" to "1."
Attached to the arm 83 is the drop rod 84 and working in the ordinary locking
trough a tappet 85 is attached to the required signal lever (for the purposes of
description a starting signal lever), its end terminating in a hook the latter being
numbered 89. The object of this is that when the rod 84 is raised on to the
cover 88 of the trough 87 by the withdrawal of the staff (the starting signal lever
being thus free to be moved), the bent piece 89 in moving forward when the lever
is operated comes into contact with rod 84 and knocks or moves it into the hole in
the cover 88 of the trough 87 so that when the lever is put back the rod drops and
pierces the tappet 85 so locking it in the normal position. The locking trough or
box is numbered 87 and the cover 88; in this cover there is a hole for the drop rod 84
to go through and there is also a corresponding hole in the tappet 85 which in the
normal position of the lever, that is, "danger" position, the drop rod 84 is through
thereby locking the tappet in the normal position of the lever. When the staff is
withdrawn the underneath projection 101 operates the rocking bar 81, the arm 83

page_text: and the drop rod 84 so that the latter rests upon the cover of the locking box 87.
The starting signal lever is now free to be moved.
In this condition of the line, A has withdrawn a staff, the starting signal has
been lowered to the "safety" attitude and the driver is free to proceed from A to B.
If now A should desire to give B sanction he is powerless to do so because the
movable magnet 47 at B cannot be energized because B having plunged to give
sanction to A has revolved the ebonite wheel 44 and the groove 43 in the latter has
raised button 42 of spring 41 and broken contact between the latter and contact
piece 45; whatever operation A may do in the nature of plunging B is powerless
to withdraw a staff as the current is broken down so that his movable magnet,
similar to 47, is not in a condition to be energized and therefore a staff cannot be
withdrawn from B for a train in the direction of A.
Suppose that A wishes to send a second train to B the first not having arrived
there (it is not material to the working of our invention whether it has arrived
there or not because a separate sanction must be given by B for every staff that
he wishes to withdraw), he can move his magnet 47 into position over any required
staff he wishes to move; the action is the same of the magnets 47 withdrawing
the pawl 97 free of the teeth on the upper edge of the staff, No. 2 staff is therefore
free to be withdrawn; when it is withdrawn the current is broken to B, in the
manner previously described, which operates the dial at B from "1" to "2."
The withdrawal of any further staffs from A is simply a repetition, so far as
operation goes, of Nos. 1 and 2 previously withdrawn.
Now, when the staffs arrive at B, in order that a train may proceed from B to A
the exact number of staffs that have been withdrawn and sent to B must be
reinserted in the instrument at B; the first in being reinserted, by means of the
projection 101 operates the rocking bar 81 moving it from the normal position to
the left, also moving the bar 78 connected to the latter in the same direction as the
rocking shaft; the spring 77 in moving in this direction depresses pin 75 thereby
lowering the rod 73 and piece 74, also pressing down arm 61 and forcing pin 62
into the teeth of the ratchet wheel 68 revolving the wheel and altering the index
from "2" to "1." The action now of inserting No. 1 staff performs a like
operation but turns the index from "1" to "0." Through the action of the
insertion of the last staff the ebonite wheel 44 is brought to the normal position
and the button 42 drops into the groove 43.
The instruments are now normal and B is in a position to request a train
from A and A. to give sanction so that B may send a train.
Every sanction that is given by the operator on the instrument revolves the
ebonite wheel 44 a determined distance so that if there were six permissions given
there would be six specified operations of the ebonite wheel, and correspondingly
when the staffs are reinserted there are six corresponding backward movements of
the ebonite wheel so that the insertion of the last returns the wheel normal so that
the button 42 may drop into the groove 43.
We have described the action that B has given sanction to A and A has acted
on that sanction and withdrawn two staffs: but, suppose now that it is not convenient
to act on the sanction and send a train from A to B, but, on the other hand,
through the exigencies of traffic, B wishes to send a train in the opposite direction,
that is, to A, all that A has to do is to reinsert the staff he has previously withdrawn
into his own instrument which re-establishes the normal condition of the instruments.
By the reinsertion of the staff the rocking bar 81 is moved from normal to the left,
depressing spring 9 and making contact with 11; this puts battery 12 into operation
(it should be mentioned that this battery 12 is a strong battery), and the contact
thus made sends a current from spring 11 to spring 9, along the wire 8, through
the contact springs 8ª and 8° which are placed at the back of the starting signal
lever 86, to the instrument at B; when the starting signal lever 86 is over the
lower spring 8 drops clear of the upper spring 8b and therefore electrical connection
is broken down through line wire 8 between A and B; the current passes to
spring 9 in B's instrument, to spring 10, through wire 15 to spring 16 and contact

page_text: piece 17, wire 18, through spring 19 and plate 22 to the point 28, the resistances
being so arranged that the greater portion of the current goes through wire 29 and
through magnet 33 to earth (the remaining portion of the current would go through
the polarized relay working the tongue 38 on same and ringing the bell 50 at B
intimating thereby that A has reinserted his staff), the armature 60 is attracted,
lever 61 is forced down, pin 62 moving the wheel 68 so that the indication is
changed from "1" to "0."
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we wish it to be
understood that we do not claim broadly the facility of being able to send more
than one train in the same direction on single lines of railway, but what we do
claim is :-
:-
1. Apparatus for a permissive block system on single line railways, whereby
more than one train may be despatched from one section (say A) in the direction
of another section (say B), whilst no train is permitted to be despatched from B in
the direction of A until the visual authorities (staffs) withdrawn for the sending
of trains from A to B have been reinserted in either instrument, substantially as
illustrated and described.
2. In apparatus for controlling traffic on single line railways, a movable electro-
magnet or movable electro-magnets (say at A) which are energized by sanction
from the other station (say B), the said magnet or magnets being employed for
permitting the withdrawal of staffs, substantially in the manner and for the purposes
herein described and as illustrated on the drawings.
3. In apparatus for controlling traffic on single line railways, an index (say at B)
operated substantially by the joint action of the mechanical plunging at, say B, and
the fulfilment of the sanction, say at A, by the withdrawal of a staff, the latter
action electrically completing the movement of the index at B, substantially as
described and as illustrated on the accompanying drawings.
4. In apparatus for controlling traffic on single line railways, arranging that the
starting signals are normally locked and are only able to be moved to the worked
position by the withdrawal of a staff in the instrument at the section and in the
direction to which the starting signal applies, substantially as described and
illustrated in the drawings annexed.
5. In apparatus for controlling traffic on single line railways, arranging that if
the starting signal lever is over in the worked position a staff cannot be reinserted
in the instrument at the section and in the direction to which the worked lever
applies until the said starting signal lever has been replaced to its normal position,
substantially as described and illustrated.
6. In apparatus for controlling traffic on single line railways, arranging that if
the starting signal is in the worked position at (say A) and the withdrawn staff has
been sent from A. in the direction of B, that while the starting signal is in this
position electric connection is broken down between A and B so that A cannot give
permission to B to send a train in the direction of A until the starting signal
lever (at A) has been replaced to the normal or "danger" position, substantially as
described and illustrated in the drawings annexed.
Dated this 1st day of November 1894.
JOHN P. O'DONNELL,
70 & 71, Palace Chambers, Bridge Street, Westminster, S. W.,
Agent for the said Applicants.