Improvements in and relating to Block Signalling Apparatus for Railways.
Year: 1899

page_text: Date of Application, 31st Jan., 1899-Accepted, 27th May, 1899
COMPLETE SPECIFICATION.
Improvements in and relating to Block Signalling Apparatus
for Railways.
A communication from GEORGE BLISS WINTER, A.M.Inst. C.E., A.I.E.E.,
Assistant Engineer, South Indian Railway, Trichinopoly, in the Presidency
of Madras.
We, GEORGE BELOE ELLIS, of the Firm of J. C. Mewburn & Ellis, of 55 and
56, Chancery Lane, in the County of London, Chartered Patent Agents, and
SARAH FLORENCE WINTER, of 28, Clipstone Avenue, Mansfield Road, Nottingham,
Widow, 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:-
This invention has for its object improvements in and relating to block signalling
apparatus for railways and it consists chiefly of improvements in the apparatus
described in the Specification of British Letters Patent No. 6864 of 1895 granted
to the late George Kift Winter and the said George Bliss Winter.
The improvements have for object to enable the block apparatus at the station
towards which the train is to proceed to be controlled in such a manner that
permission once given by that apparatus to the station in the rear for a train
to proceed cannot be revoked if:-
(1) The train has once entered the section between the two stations, or if
(2) On the arrival of the train at the station at either end of the section, any
portion of the train be left between the two stations.
"
The means by which these improvements are carried out are as follows:-
In the specification already referred to was described the method by which
line clear" was given by the station master at the station towards which the
train is to proceed. Before "line clear" could be given, it was shown, that the
switch handle had first to be placed over to "on," and this could only be done
during a prolonged current sent from the station which is to despatch the train.
When at " on" it was there locked. Three methods were described showing how
the switch handle, could be unlocked to enable the switch handle to be brought
to "off" which we here recapitulate in order to show the improvements forming
the subject of our present invention;-
Having put the handle to on "the signalman cannot put it back to "off"
until:
FIRST METHOD.
1st. The home or distant signal is lowered.
2nd. Until the train arriving has pressed a trigger which in the ordinary way
is set in the act of lowering the home or distant signal.
SECOND METHOD.
If the rules of working are so framed that ballast and material trains have to
go right through the section and not allowed to return to the station from which
they started without going to the station at the other end of the section, it will
only be necessary to provide a contact maker covered by a glass which must be
broken before contact can be made to allow handle to be replaced to "off" when
it is required to cancel a block.

page_text: THIRD METHOD.
But if, as is usually the case, the rules allow ballast and material trains to back
to the station from which they started without going through, it is necessary
to have a simpler procedure. This is afforded by an additional button or plunger in
the instrument which is kept under lock and key by the station master and should
only be used by him.
.
This plunger is inoperative except when a prolonged current is being received
from the distant station so that, should it be required to remove the block either
in consequence of a ballast train returning or a train unable to proceed, this key
may be used to enable the section to be cleared.
The station to which the train has returned gives the arrival signal followed
by a prolonged beat and the station to which the train would under ordinary
circumstances have gone is then by pressing this protected plunger enabled to bring
his switch handle from "
on to "off" and so give the signal allowing the ticket
drawer at station to which the train has returned to be replaced and the block
to be cancelled.
ور
We now prefer not to use the first and second methods of releasing the switch
handle. The second method has been very little used and is not required. when
the third method is available. The first method will not be necessary by reason of
the improvements made on the third method in accordance with our present
invention.
These improvements have for object the prevention of the use of the above
described third method during the time:-
(1) That the train remains on the section between the two stations, and
(2) That any portion of the train remains on the section even though one portion
of the train may have arrived at either end of the section.
The means by which these improvements are carried out according to the present
invention are as follows:―
The coil which actuates the lock on the switch handle when the latter is at "on,"
is now so connected with the other portions of the local circuit in the instrument
that the liberation of the lock by means of the local current flowing through the
said coil is made dependent upon the position of the polarized relay tongue.
This means that the current can be made to flow through the said coil when the
relay tongue is against its normal contact stop but not when the relay tongue is
against its other contact stop.
The liberation of the switch handle when at
the following conditions:-
-
66
on is therefore dependent upon
(1) The closure of the armature contact which is effected during the receipt
of a prolonged current from the distant station.
(2) The pressing of the button or plunger at the side of the instrument known
as the station masters key.
(3) That the relay tongue is in its normal position against the normal contact
stop which position is dependent upon the direction or sense of the current being
received.
Should however the relay tongue be moved over from its normal contact stop to
its other stop by reason of the incoming current being of the wrong sense or direc-
tion, the coil which actuates the lock on the switch handle when at "on," will be
cut out of the local circuit and the current will not flow through the coil even
although conditions (1) and (2) are still in operation.
"3
Our object being the prevention of the use of the third method hereinbefore
referred to during the time the train or any portion thereof remains on the section,
and, having now modified the connections of the instrument so that the lock on
the switch handle when at "
on can only be released when the incoming current
1s in its proper sense or direction, all that now remains to do is to provide a
mechanical means by which the train on entering the section and as long as it or
any portion thereof remains on the section shall determine the direction of the
incoming current at the station towards which the train is proceeding, that is to

page_text: say, the station which gave "line clear" when a prolonged beat is given by the
station in the rear. This is carried out in the following manner :-
At each end of the section beyond the outermost points of the station yard is fixed
an apparatus hereinafter called the train protection apparatus. This apparatus is
electrically inserted between the line wire and the line terminal of the block instru-
ment and between the earth "terminal of the block instrument and the "earth"
wire. The instrument is mechanically connected with a vertical rod or plunger
placed centrally between the two rails of the track. This rod or plunger is actuated
twice during the passage of every complete train by means of arrangements here-
inafter described. The object of this apparatus is to control the position of the
polarized relay at the forward station after the complete train has entered the
section so that the switch handle at that station remains locked at "on" and cannot
be brought to "off" until the complete train has passed over this apparatus at
either end. The description of this train protection apparatus divides itself into
two parts electrical and mechanical.
DESCRIPTION OF THE ELECTRICAL PART.
The apparatus consists of four terminals exterior to the instrument for the
purpose of exterior connections. These terminals are each electrically connected
to one of each of four springs which press upon a revolving commutating drum or
cylinder. This drum or cylinder is made to turn a complete revolution in 12 steps
or any other number of steps being a multiple of four. Calling the four terminals
of the instrument to which the exterior wires are connected A, B, C and D, respec-
tively the connections on the drum are such that at each step of the revolution of
the cylinder the connections of these terminals to one another are varied in the
following manner.
The cycle of commutation is made in four steps:-
-
Starting position:-A is in connection with C.
Do.
First step
Do.
Second step
Do.
Third step
Do.
B is in connection with D.
A is disconnected from C.
B is disconnected from D.
A is connected to D.
B is connected to C.
A is disconnected from D.
B is disconnected from C.
The fourth step is the same as in the starting position and in like manner the
cycle is repeated in regular succession during the rotation of the cylinder.
DESCRIPTION OF THE MECHANICAL PART.
The cylinder referred to in the description of the electrical part is made to rotate
step by step by means of an oscillating vertical arm after the manner of a ratchet
drill. The spindle of the cylinder extends beyond the cylinder. Upon this exten-
sion is slipped loosely the fulcrum of the rocking vertical arm referred to and
contiguous to the rocking arm is keyed to the same spindle a ratchet wheel
having 12 or any number being a multiple of four teeth. Upon the rocking arm
or lever is a pawl fixed so that at every forward motion of the arm the pawl
engages with the ratchet wheel and causes the cylinder to rotate an amount
depending upon the throw of the rocking arm. On the return stroke of the arm
the pawl becomes disengaged from the ratchet wheel and causes no rotation of the
cylinder the cylinder thus rotates only in one direction. The play of the rocking
lever is limited by two stops. The extremity of the lever is connected through
one or more levers either rigidly, or by means of counter-weighted levers as found
convenient to a vertical rod or plunger situated centrally between the rails of the
track in such a manner as to convert a vertical movement of the plunger into the
horizontal movement of the rocking lever. The vertical movement of the plunger
is made twice during the passage of every complete train and for this purpose a bar
terminating in a roller is attached to each end of the train in such a manner

page_text: as to cause the depression of the plunger during the passage of the roller. The
bar in front of the train may be attached to the cow catcher and adjusted to the
correct height. A similar but longer bar will be required for the rear end of
the brake van, the roller end being adjusted to the same height as that on the
cow catcher. The depression of the plunger can be effected by the deflection of
a bar placed over it-the deflection being caused during the passage of the roller
referred to or by a treadle bar hinged at one end and supported on springs at the
other; in either case, the bar is to be suitably cambered as to cause the depression
of the plunger to take place gradually and without shock to the working parts.
Having now described the separate parts of our invention it is necessary to
explain how the several parts are to be connected together and the precise manner
of their working.
It is assumed that two block instruments whose connections have been modified
as herein before described are ready to be inserted into the circuit connecting
station A with station B. One train protection apparatus" must be fitted up at
each end of the intervening block section beyond the outermost points of the
station yard. At each of these stations the line" terminal of the block instru-
ment is connected with the before described "A" terminal of the "train protec-
tion apparatus" and the "earth" terminal of the block instrument is connected
with the "B" terminal of the aforesaid apparatus. The "C" and "D" terminals
of the "train protection apparatus" must now be connected with the "line" and
"
earth
wires respectively connecting the two stations. Having done this and
having adjusted the cylinders of the "train protection apparatus" at both stations
so that terminal A is in connection with "C," and "B" with "D," both block
instruments will now be connected together in their normal manner and the
block instruments can now be manipulated precisely as if no train protection
apparatus was inserted.
*
"
It will be noted that under these conditions the "line" terminal of the block
instrument at station A will be joined to the "line" terminal of the block
instrument at B through the line wire, and the "earth" terminals of both instru-
ments will be connected together through the earth.
Now suppose a train be ready to start from station A to station B. The line
having been "
blocked" in the usual manner (as described in the Specification of
the British Letters Patent before referred to) and the "line clear" ticket having
been given to the driver, the train is started. On its passing over the plunger
placed in the centre of the track it actuates that plunger twice. The plunger being
actuated twice causes the cylinder to rotate two steps in its revolution and the
terminals of the "train protection apparatus " will therefore be connected as
follows:-
66
"A" will be in connection with "D"
"B" will be in connection with "
C."
It follows from this therefore that the "line" terminal of the block instrument
at A" is no longer connected with the "line" terminal of the block instrument
at "B," but is instead connected with the "earth" terminal of the latter instru-
ment. Similarly the earth" terminal of station A is now disconnected from
the terminal of the same name of the block instrument at B but is connected
instead to the line terminal of the latter instrument.
Should now the station master at A induce the station master at B to believe
the train to have returned to A when it has not, and should the station master
at station A give a prolonged beat in order to enable station master at B to release
his switch handle, the out going current given by A will arrive at B in the reverse
direction or sense and so cause the polarized relay tongue of the instrument at B
to move over from its normal contact stop to its other stop. The coil which unlocks
the switch handle will therefore be cut out of the local circuit, and the station
master at B will therefore be unable to bring his switch handle to
third of the three methods described in the earlier part of this specification.
off"
by the

page_text: Suppose
the plunger fixed at that station, and in doing so, actuates the plunger twice and
80 causes the terminals on the "train protection apparatus" fixed at that station
to be connected together as follows:-
"A" will be in connection with "D"
"B" will be in connection with "C."
This has the result of restoring the proper connection of both block instruments.
The switch handle at station B may now be released either by the first of the three
methods of doing so described in the earlier part of this specification or by the
third method. In the latter case the rules of block working would be altered so
as to allow of the use of this method on arrival of the train at B.
Suppose that instead of proceeding right through the section the train was
required to return to the station from which it started. On arrival at that station,
it would actuate the "train protection apparatus "there twice and would in
consequence complete the cycle of the 4 steps of commutation and so return the
connections as in the original position and in the example given the connections
would be thus:
"
"
A in connection with "C"
"B" in connection with "D,"
which results in restoring the proper connection on both block instruments.
Should however by any mistake or mischance, the train become parted and
only a portion of the train arrive at either stations A or B, the train being incom-
plete would in consequence of the actuating bars being attached to each end of the
complete train, arrive at the station with only one actuating bar, and hence, in
passing over the "train protection apparatus," the incomplete train would actuate
the plunger once only. This has the effect as previously described of disconnecting
terminals "A" and "C" and 13" and "1" so that both block instruments
would become disconnected from one another and the section could not therefore
be cleared."
If the rules were such as to insist that all trains entering a section should carry
two actuating bars, one at each end of the train, the section, under the circum-
stances just referred to, could not be cleared until a relieving train had entered
the section and brought out the vehicles or vehicles left behind in the section to
the station to which they should have arrived had they not been left in the section.
Another way of securing that the section should not be "cleared" until the
missing vehicles. had been actually brought out of the section would be to make
the relieving train or engine carry no actuating bar.
In the drawings accompanying this specification,--Figure 1 is a diagram of the
connections for carrying out the third method as described in the Specification of
Letters Patent No. 6864 of 1895 above referred to. It is here reproduced in order
to show the more clearly the present improvements on the said third method.
Referring to the diagram, when the distant station sends a prolonged beat,
contact at is closed. Assuming this contact closed, the station masters key S K
to be depressed, and the relay tongue R to be against its normal contact stop T;
the local current will flow as follows:-From the positive pole of the line battery LB
to R, thence to T, up through M¹, then to the right through the bottom contact
of the station masters key S K, thence through the bell coil at B, through con-
tact C and thence to the negative pole of the line battery L, B. The current in
so flowing will energise the electro magnet M¹ and the switch handle will there-
fore be released when at "on."
Now if the relay tongue is placed over against its other contact stop S
and assuming contact C to be made as before and the station masters
key SK to be depressed; the local current will flow as follows:-From
the positive pole of the line battery L B to R, thence through S, up
through G, thence to the left and then down through F, through M, and

page_text: then up through M, to the right through the bottom contact of the
station masters key S K, through the bell coil at B, the contact at C, and
thence to the negative pole of the battery. The current in flowing thus has
energised the electro-magnets F, G, M and M. Now the principle of our improve-
ments in the interior connections of the block instrument consists in only permitting
the local current to flow through M when the relay tongue is against its contact
stop, T. Further-our improvements consist in, preventing both coils F and G
being actuated simultaneously.
Figure 2 shows the manner in which the improved connections are carried out.
Assuining as before, contact to be made at C and the relay tongue R to be against
its normal contact stop T. Starting from the positive pole of the line battery L B,
the current flows through the relay tongue R, thence through the normal contact
stop T, then up to the station masters key SK through the bottom contact of
this key, up and to the left through the coil M₁ which actuates the lock on the
switch handle when at on," thus actuating the electro-magnet, liberating the
switch handle when at
The current then flows down and then up through
the coil F, thence to the right through the bell coil at B, down and then up
through the contact C and thence to the negative pole of the line battery. Under
these conditions therefore, that is with the relay tongue against the normal con-
tact stop T, the switch handle when at on can be released.
.6
011.
دو
<
"
Now if the relay tongue is placed over against its other contact stop S, no
current will now flow through the coil M', for, on tracing the connection from S
through G, F, M through the bottom contact of station masters key SK, through
this key and down to T; a break will be found to occur at T. Neither can the
current flow through F and G simultaneously, for the current, after flowing
through G, finds a short circuit to the bell coils by the wire running off to the
right on the diagram opposite G, through contact Č, and thence to the negative
pole of the line battery.
Figures 3, 4 and 5 of the accompanying drawings represent the plan, side eleva-
tion, and back elevation respectively of the "train protection apparatus." L is
a vertical oscillating arm or lever which oscillates between the stops to and th.
When it is in its normal position it is against the stop t, and when the plunger
placed in the centre of the track is actuated it rocks over to tb and as soon as the
plunger is released it falls back to ta by means of the counterweighted lever Q.
This lever Q is weighted at w.
The pawl which causes the commutating drum or cylinder D¹ to revolve is
shown at P; it is shown attached to the arm L, and it engages with the teeth
of the wheel D2 which is fixed on the axle X of the drum.
The construction of the commutating drum D' shown in Figures 3, 4 and 5
is shown more clearly on a larger scale in Figures 5 to 5* inclusive.
Figure 5 is a front elevation of the drum. Figure 5 is a development of the
peripheral surface of the drum. Figure 5 is a cross section through the drum
taken on the line 5° -5° of Figure 5. Figure 5 is a cross section through the
drum taken on the line 5-5 of Figure 5. Figure 5 is a longitudinal section
through the drum taken on the line 5-5 of Figure 5.
As shown, the drum D' (which is made of well seasoned wood or other suitable
insulating material) is provided with four peripheral rings a, b, c, d of copper,
brass or other suitable conducting metal. Each of the two outer rings c, d is a
continuous ring, but each of the two inner rings a, b is cut up into twelve insulated
segments. The two outer rings c, d are insulated from each other and likewise
the two inner rings a, b are insulated from each other by means of three interposed
rings e, f, g of vulcanite inserted in the drum.
Referring to Figure 3, it will be seen that four springs S are provided, each
spring pressing upon one of the four rings a, b, c, d. The spring which presses
upon the ring a is connected to the "A" terminal, and the spring which presses
upon the ring b is connected to the "B" terminal. Likewise, the springs which
press upon the outer rings c, d are connected respectively to the "C" and "D"
terminals.

page_text: 66
The A" and "B" terminals are connected respectively with the
وو
line and
con-
earth terminals of the block instrument, and the "C" and "D" terminals
and
wires
"earth"
with the "line"
re respectively connected
The four rings a, b, c, d
ecting the two stations on the block section.
as
the drum D¹ to produce the sequence
re SO cross-connected on
of the connections of the above terminals with one another during the rotation of
he drum in the manner already herein before described. These cross-connections
of the rings are indicated by thick black lines running partly across Figure 5".
A" is in connection with
In the normal position of the drum D¹ terminal
terminal C, and terminal "B" is in connection with terminal "D" as indicated
by thick black lines k in Figure 3.
The drum can only rotate, viewing it as in Figure 4. in a clockwise direction ;
it is prevented from revolving in a counter-clockwise direction by the pawl shown
at R.
The train protection apparatus" should be fixed so that the centre of the
track is on the right of the instrument viewed as in Figure 4.
Figure 6 of the accompanying drawings indicates the manner in which the
train protection apparatus can be connected with the plunger P placed in the
centre of the track, in order to convert a vertical movement of the plunger into a
horizontal movement of the rocking lever L.
The train protection apparatus" is seen in outline on the left of the figure.
Vis a rocking arm or lever which rocks or see saws in a vertical plane. Towards
the extremities of this rocking lever on either side of its fulcrum rest two
weights W₁ and W2 of which W2 is the heavier. The weights resting in their
natural position on the rocking lever V, the heavier weight W2 over-balances the
smaller weight and causes the rocking lever to take up a position as shown in the
figure. Each of these weights is attached to the end of an arm or lever (shown in
Figure 7, but not shown in Figure 6 for the sake of clearness) pivoted behind the
plane of the figure about an axis Y Z. The weighted levers are perfectly
independent of one another.
The vertical dotted line M N to the right of the figure indicates the centre of the
track. T represents a cross-section of a T-iron treadle bar laid in the centre of
the track and parallel to the line. This treadle bar is connected in a suitable
manner to a vertical rod or plunger 1. The travelling of the roller, referred to in
the earlier part of this specification, over this treadle bar T causes a downward
movement of the plunger P. The plunger P may be made of gas piping or in
any other section suitable to receive compressive forces. Two bell cranks, con-
nected with one another by the necessary length of piping, transmit the vertical
downward movement of the plunger P into the vertical downward movement of
the rod R.
The vertical downward movement of the rod R serves to lift the weight W².
The weight W2 being lifted; W1 on the other side of the fulcrum of the lever V
not having any weight to counter-balance it, falls, and in doing so, rocks the
lever U and causes to move over from ta to tb.
The weight W2 falls down on the removal of the roller from off the treadle bar,
and in doing so, it over-balances weight W₁ which releases the lever U and
allows L to fall back again into its normal position.
when
The arrows in this figure show clearly the direction of movement of the con-
necting rods when a vertical downward movement is given to the plunger P,
the treadle bar is actuated.
The manner in which the vertical movement downward of the rod R causes
the weight W2 to be lifted up is shown in Figure 7.
Figure 7 is an elevation of the weight W2 viewed in a direction at right angles
to the direction in which it is viewed in Figure 6.
Weight W', unlike W2, has no connection with any connecting rod, its function
is merely to rest on the arm of the rocking lever.

page_text: Figure
of the accompanying drawings is a side elevation of the treadle bar.
It consists of a T-iron bar of a convenient length and sectional dimensions bent to
a radius such that the "versed-sine" measured from off the chord line E Fis
approximately six inches. The bar might be made to deflect to the required
amount with a weight of say 600 or 1200 lbs. If the bar is made so that the
chord E F measures 10 feet the bar should be curved to a radius of 25 feet.
Through the web of the T-iron bar and about three inches from each end is
passed a strong steel pin or bolt, this pin should be securely fastened to the web
of the T-iron. Each pin rests in slots cut in the supporting jaws of a cast iron
chair as shown in the figure.
The chairs supporting the pins above referred to are shown at C C. These
chairs may be of cast iron, with cheeks or sides as shown in the figure. The chairs
are bolted down to the sleepers S in the manner shown by a bolt passing through
the cheeks and sleeper. The chairs must be so spaced centre to centre apart that
the pins on the treadle bar rest in the slots close up against the inner ends of the
slots, so as to allow expansion of the bar outwards when the roller travels over the
bar. The treadle bar is here so designed as to always expand in the direction in
which the train runs, and the thrust due to the horizontal motion of the train is
always borne by the rearward pin. The line E F represents the rail level and
the line A B the path of the lowest edge of the travelling roller. This path A B
should not be less than four inches above rail level. 1 is the vertical rod or
plunger already referred to.
Figure 9 is a diagrammatic view of the cow-catcher of an engine, showing the
attached roller V. The details of the fixture of this roller can best be considered
with reference to the details of the construction of the cow-catcher. As in Figure 8,
the line E F represents the rail level, and A B the path of the lowest edge of the
travelling roller.
Figures 10 and 11 represent to a much smaller scale the arrangement for fixing
the roller V to brake vans. The roller V is fixed to the lower end of a rod R.
The rod R is hinged at H to a flat iron bar fixed to the bottom timbers of the
floor of the brake van. The roller V in Figure 10 is free to move upwards about
the centre H, but is prevented from falling below its proper level, or on to the
line, by a stirrup or sling (not shown in the figure for the sake of clearness). N is
a cast or wrought iron block which is rotated by means of the handle at M at
the rear end of the brake van. The spindle on which N rotates is supported from
the floor of the brake van; this support has been omitted for the sake of clearness.
In Figure 10 the roller is shown inoperative, it is unable to deflect the treadle
bar placed in the centre of the track for the reason, that the block N being out
of the way, there is nothing to prevent the roller V from rising upwards unopposed
when riding over the treadle bar. When however the handle M is pushed down
as shown in Figure 11, the block N is rotated so as to form a stop or block pre-
venting the roller V from rising. The roller V not now being able to give way
upwards when passing over the treadle bar, the treadle bar is deflected and the
train protection apparatus is consequently actuated.
وو
The arrows in Figures 10 and 11 represent the direction in which the vehicle
is supposed to be running. The rod R may be either in tension or compression in
accordance with the direction in which it is running, and the block N always in
compression, and these parts should be designed accordingly.
Having now particularly described and ascertained the nature of the said inven-
tion as communicated to us and in what manner the same is to be performed,
we declare that what we claim in respect of block signalling apparatus of the kind
described in the Specification of British Letters Patent No. 6864 of 1895, is:-
66
1. The controlling of the lock on the switch handle after it has been placed over
to on" by the mechanical action of the train on entering and on leaving the
section, so that the switch handle cannot be released after the train has once
entered the section between two stations, nor while it remains on the section

page_text: between two stations, substantially as herein before described with reference to
the accompanying drawings."
2. Putting a mechanical actuating device on to each end of the train, for the
purpose of ensuring that the whole train shall arrive at the station before the
section can be "cleared" on the instrument, substantially as hereinbefore described.
3. The arrangement of the connections of the local circuit in the block instru-
ment as shown in Figure 2 of the accompanying drawings for the purpose:-
(a) Of preventing the release of the switch handle during a prolonged current
in the reversed direction from the distant station coupled with the
pressure of the station master's key, and
(6) Of only permitting the local current to flow through the coil G which
enables the ticket slide only to be withdrawn.
Datad this 20th day of January 1899.
J. C. MEWBURN & ELLIS,
55 and 56, Chancery Lane, London,
Chartered Patent Agents.