Improvements in Block Signalling Apparatus and Interlocking same with Outdoor Signals.
Year: 1893

page_text: Date of Application, 29th Mar., 1893
Complete Specification Left, 20th Dec., 1893-Accepted, 3rd Feb., 1894
PROVISIONAL SPECIFICATION.
Improvements in Block Signalling Apparatus and Interlocking
same with Outdoor Signals.
I FREDERICK THOMAS HOLLINS of Saltley House Forest Drive Leytonstone
Essex, Telegraph Engineer to the Great Eastern Railway do hereby declare the
nature of this invention to be as follows:-
The object of this invention is to further improve my previous invention under
Patent No. 22093 of December 2nd 1892 for controlling the block instrument
indications given to the station in the rear of any block section by so interlocking
the signal lever of the signal controlling the block section in advance that the
manipulation of the one is controlled by the other. I previously proposed to
provide a screen which may be of any suitable shape together with a box or case
to cover over the two plungers of Tyers single wire double line block instrument
and which screen was provided to cover first the red or Line blocked plunger and
then the white or Line clear plunger alternately and which said screen was caused
to revolve by means of a spring or by gravity or other equivalent device and so
that when the said screen was turned from over the red plunger to cover the white
one it was locked in that position and could not again be released until the signal
lever of the controlling signal for the section in advance had been manipulated su
as to take the signal off and until the signal had again been put to danger behind
the train.
I have found it desirable in some cases to modify and improve this so that where
the signal controlling the section in advance does not require taking off for the
approaching train for which Line clear was last given the signalman may by
manipulating a special key or plunger or equivalent device unlock the screen and
allow it to revolve over so as to enable him to again give Line clear for a following
train.
In some cases I provide this special key or plunger with a number indicating
device or index or recorder so that every time it is made use of the fact may be
indicated by means of consecutive numbers or recorded in any other suitable
manner so that a check may be kept on the number of times this device is made
use of. And in some cases it is desirable that the signalman himself shall not see
the indications which this special device causes or records but so that its indications
may be taken from time to time and checked with the numbers or other entries
equivalent thereto made in the signalmans train book. In this case the indicator
of whatever form would be covered up and the said cover or screen locked.
Where I make use of a locking instrument to actually lock up the controlling
signal for any section so that the signalman in advance shall have to unlock the
said controlling signal 1 in addition arrange a locking bolt or latch or equivalent
device in the block instrument so that when the white plunger has been plunged it
is automatically locked so that it cannot again be plunged until the red plunger
has been plunged and this causes the white plunger again to be unlocked. In
addition to and in combination with this device I also provide a key or spring
catch arrangement equivalent to a Morse key and this key or catch arrangement
normally holds up or otherwise controls the said bolt or latch device for locking
the white plunger and its electrical connections are such that normally the
ordinary battery for working the block needles or indices is joined up for use
whenever the red or the bottom plunger is plunged. But whenever the white
plunger is plunged this catch or key device lets the locking bolt or latch arrange-
ment fall and at the same time switches in an extra battery so that when the

page_text: So that
white plunger is plunged a larger number of battery cells are in circuit sufficient
not only to move the block instrument needles but to actuate the locking
instrument which is in the line circuit at the opposite end of the section.
when the red plunger is used and when the third or bell plunger is used the
smaller battery only sufficient for the block instrument is in circuit and the larger
battery is only in circuit during the time the white plunger is being plunged.
The locking instrument must be in the line circuit between the earth terminal of
the block instrument and the earth or it may be so arranged that it is only in
circuit when the signalman at the same box depresses a key or plunger so as to
deviate the line circuit so that the current sent by the signalman in advance shall
pass through the coils of the locking instrument only when such key or plunger is
depressed that is so as to require the concurrence of both men to unlock the
signal lever.
The locking instrument itself I arrange by connection or attachment to the tail
piece of the signal lever (or to any other suitable part of the said lever) so that
the motion of the lever to take the signal off shall be prevented until the current
has pulled a stop or bolt out of the way.
When the armature of the locking coils has been actuated it is held back by a
catch until the signal lever has been manipulated and the motion of the armature
also moves a disc or indicator screen which shall indicate when the signal is
"locked" and when it is "free" or give other equivalent indications.
In
The motion of the signal lever on the signal being taken off and again put to
danger will release the armature and the lever will thus become relocked.
case of failure of the electrical arrangement to unlock the signal lever or for
other special causes when required it is necessary to provide a mechanical means.
of doing so and I also provide a special plunger or key or equivalent device to the
locking instrument for doing this but so that each time it is done it shall indicate
upon an index or recorder as may be required each time this special mechanical
releaser is made use of. This also may be covered up or open as may be desired
for immediate or occasional reference or check. And I also in some cases instead
of causing the red plunger when first plunged to unlock the white plunger provide
this device with coils so that the said device shall only be actuated to unlock the
white plunger when an electrical rail contact in advance of the controlling signal
at that place has been actuated by the train for which the road was given by the
previous manipulation of the white plunger. At places where it is not thought
necessary to lock the signal lever and for it to be under the control of the
signalman in advance I may sometimes arrange that such controlling signal is.
automatically locked at the signal box from which it is manipulated and only
released for use each time the red or Line blocked plunger is manipulated.
This would ensure that every time Line clear has been given for a train it should
not be possible for him to take off his signal for that train until he has given Line
blocked to the signal box in the rear. And I may make use of these devices
separately or in combination as I may find necessary to suit the exigencies of the
traffic arrangements on the line or at the places at which it is provided.
The improvements herein provided for the three plunger form of Tyers single
wire block for double lines is applicable also to the other forms of Tyers block in
which only one plunger is used and the commutator turned mechanically for the
Line clear or Line blocked current to be sent as may be required and the same is
also applicable to other forms of block apparatus either with one two or three
wires for needle block or in which discs are used instead of needles to give the
several block indications.
In the Tyers mechanically turned commutator form the turning of the
commutator from the blocked current side to the clear current side will join in
circuit the extra battery to unlock and the first plunge will then cause the full
current from both batteries to be transmitted to unlock the signal lever at the box
in the rear and will also break down the extra battery or otherwise cut it out of
circuit and only leave the small battery in circuit for the next plunge. The

page_text: commutator when to Line blocked is locked and the taking off of the signal lever
of the controlling signal for section in advance and putting the same to danger
unlocks it but I arrange that this may also be done without the signal lever by
means of a special key or plunger or other equivalent device but I here also
provide as previously described the special device for recording or indicating the
number of times this special unlocking device is made use of.
Dated this 29th day of March 1893.
Improvements in Block Signalling Apparatus and Interlocking
same with Outdoor Signals.
I FREDERICK THOMAS HOLLINS of Saltley House Forest Drive Leytonstone
Essex, Telegraph Engineer to the Great Eastern Railway Company, 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 object of this invention is to further improve my previous invention under
Patent No. 22093 of December 2nd 1892 for controlling the block instrument
indications given to the station in the rear of any block section by so interlocking
the signal lever of the signal controlling the block section in advance that the
manipulation of the one is controlled by the other. I previously proposed to
provide a screen which may be of any suitable shape tegether with a box or case
to cover over the two plungers of Tyers single wire double line block instrument
and which screen was provided to cover first the red or Line blocked plunger and
then the white or Line clear plunger alternately and which said screen was caused
to revolve by means of a spring or by gravity or other equivalent device and so
that when the said screen was turned from over the red plunger to cover the white
one it was locked in that position and could not again be released until the signal
lever of the controlling signal for the section in advance had been manipulated so
as to take the signal off and until the signal had again been put to danger behind
the train.
I have found it desirable in some cases to modify and improve this so that where
the signal controlling the section in advance does not require taking off for the
approaching train for which Line clear was last given the signalman may by
manipulating a special key or plunger or equivalent device unlock the screen and
allow it to revolve over so as to enable him to again give Line clear for a following
train.
In some cases I provide this special key or plunger with a number indicating
device or index or recorder so that every time it is made use of the fact may be
indicated by means of consecutive numbers, or recorded in any other suitable
manner so that a check may be kept on the number of times this device is made
use of. And in some cases it is desirable that the signalman himself shall not see
the indications which this special device causes or records but so that its indications
may be taken from time to time and checked with the numbers or other entries
equivalent thereto made in the signalman's train book. In this case the indicator
of whatever form would be covered up and the said cover or screen locked.
Where I make use of a locking instrument to actually lock up the controlling
signal for any section so that the signalman in advance shall have to unlock the
said controlling signal I in addition arrange a locking bolt or latch or equivalent
device in the block instrument so that when the white plunger has been plunged it
is automatically locked so that it cannot again he plunged until the red plunger
has been plunged and this causes the white plunger again to be unlocked. In
addition to and in combination with this device I also provide a key or spring

page_text: catch arrangement equivalent to a Morse key and this key or catch arrangement
normally holds up or otherwise controls the said bolt or latch device for locking
the white plunger and its electrical connections are such that normally the ordinary
battery for working the block needles or indices is joined up for use whenever the
red or the bottom plunger is plunged. But whenever the white plunger is plunged
this catch or key device lets the locking bolt or latch arrangement fall and at the
same time switches in an extra battery so that when the white plunger is plunged
a larger number of battery cells are in circuit sufficient not only to move the block
instrument needles but to actuate the locking instrument which is in the line
circuit at the opposite end of the section. So that when the red plunger is used
and when the third or bell plunger is used the smaller battery only sufficient for
the block instrument is in circuit and the larger battery is only in circuit during the
time the white plunger is being plunged. The locking instrument must be in the
line circuit between the earth terminal of the block instrument and the earth or
it may be so arranged that it is only in circuit when the signalman at the same box
depresses a key or plunger so as to deviate the line circuit so that the current sent
by the signalman in advance shall pass through the coils of the locking instrument
only when such key or plunger is depressed that is so as to require the concurrence
of both men to unlock the signal lever.
The locking instrument itself I arrange by connection or attachment to the tail
piece of the signal lever (or to any other suitable part of the said lever) so that
the motion of the lever to take the signal off shall be prevented until the current
has pulled a stop or bolt out of the way. When the arinature of the locking coils
has been actuated it is held back by a catch until the signal lever has been
manipulated and the motion of the armature also moves a disc or indicator screen
which shall indicate when the signal is "locked" and when it is "free" or gives
other equivalent indications. The motion of the signal lever on the signal being
taken off and again put to danger will release the armature and the lever will thus
become rclocked. In case of failure of the electrical arrangement to unlock the
signal lever or for other special causes when required it is necessary to provide a
mechanical means of doing so and I also provide a special plunger or key or
equivalent device to the locking instrument for doing this but so that each time it
is done it shall indicate upon an index or recorder as may be required each time
this special mechanical releaser is made use of. This also may be covered up or
open as may be desired for immediate or occasional reference or check. And I
also in some cases instead of causing the red plunger when first plunged to unlock
the white plunger provide this device with coils so that the said device shall only
be actuated to unlock the white plunger when an electrical rail contact in advance
of the controlling signal at that place has been actuated by the train for which the
road was given by the previous manipulation of the white plunger. At places
where it is not thought necessary to lock the signal lever and for it to be under the
control of the signalman in advance I may sometimes arrange that such controlling
signal is automatically locked at the signal box from which it is manipulated and
only released for use each time the red or "Line blocked" plunger is manipulated.
This would ensure that every time Line clear has been given for a train it should
not be possible for him to take off his signal for that train until he has given
"Line blocked" to the signal box in the rear. And I may make use of these
devices separately or in combination as I may find necessary to suit the exigencies
of the traffic arrangements on the line or at the places at which it is provided.
The improvements herein provided for the three plunger form of Tyer's single
wire block for double lines is applicable also to the other forms of Tyers block
in which only one plunger is used and the commutator turned mechanically for
the Line clear or Line blocked current to be sent as may be required and the same
is also applicable to other forms of block apparatus either with one two or three
wires for needle block or in which discs are used instead of needles to give the
several block indications.
In the Tyers mechanically turned commutator form the turning of the commutator

page_text: from the blocked current side to the clear current side will join in circuit the extra
battery to unlock and the first plunge will then cause the full current from both
batteries to be transmitted to unlock the signal lever at the box in the rear and will
also break down the extra battery or otherwise cut it out of circuit and only leave the
small battery in circuit for the next plunge. The commutator when to Line blocked
is locked and the taking off of the signal lever of the controlling signal for section
in advance and putting the same to danger unlocks it but I arrange that this may
also be done without the signal lever by means of a special key on plunger or
other equivalent device but I here also provide as previously described the special
device for recording or indicating the number of times this special unlocking device
is made use of.
And in order that my invention may be more fully understood I will now proceed
to describe the accompanying drawings in reference thereto.
Fig. 1 indicates one form of the screen and disc arrangement in which the screen
is released by the manipulation of the controlling signal lever for the section in
advance. And
Fig. 2 shews another form in which the screen is controlled or released by an
electro magnetic means actuated by the train itself passing over a rail contact in
advance of the controlling signal for the section in advance.
The apparatus generally and the method of working is fully described and set
forth in my Specification No. 22093 of 1892 except that there is now an additional
disc to indicate when the train has been "accepted " from the station in the rear
and the other special parts herein shown aud which will be described further on.
In Fig. 1, A is the outer or containing case, B the screen, capable of being
turned upon the axis C from its present position over the "Train accepted" disc,
by means of the knob or handle L over the "Train passed" disc G covering the
white plunger X. When it is so turned it is locked in this position by the
catch piece J on the "Train passed" disc G and also by the catch piece D on
the screen B engaging with the bevelled spring catch piece E which it pushes
back and when partly turned E snaps forward and holds D so that the screen
cannot go back.
Cases often occur where although a train may be signalled and "Line clear" given
for it it may afterwards be cancelled or it may be a train that is going no further
than the station from which "Line clear" has been given. In these cases of course
the starting signal is not taken "off" and therefore special means are required to
unlock the screen and allow it to revolve over from right to left on receipt of the
cancelling signal or on the arrival of the train which is to go no further and when
it has been shunted clear of the main line. At the bottom right hand corner of
Fig. 1 is a small plunger which when plunged catches upon the inclined catch
piece m attached to the lever n having a projection o and as this small lever no
rests against the catch piece E each time the plunger is plunged the catch piece E
being pushed back the screen is released and providing the small lever I on the
upper right hand side has been depressed and the hook J raised the screen revolves
over from right to left into the position shown in the drawing. The small plunger
in addition to depressing the lever n also moves forward the horizontally fixed
cog-wheel p having on its periphery r consecutive numbers engraved from 1 to 20
or other numbers corresponding to the number of cogs. Each depression of the
small plunger therefore moves the counter or index forward one number the object
being to record every time the screen B is released other than by means of the
manipulation of the signal lever. The signalman is also called upon to record in
his train book every time he uses this small plunger by entering the numbers con-
secutively as he uses it and thus it is a check upon the use of the said releasing
lever.
This index or numbering device is of course out of sight being covered up by
the front plate but there is a movable slide fixed over the orifice through which
(when the slide is pushed up so that the hole in the slide coincides with the hole
in the plate opposite the index wheel) the number indicated can be seen. This slide

page_text: is kept in position down and over the orifice by a hinged portion passing over a
staple and held there by means of a small padlock or other suitable means in order
to prevent the signalman from seeing the numbers indicated and thus it prevents
him from being able to make his book agree with his index should he have
wrongly used the small plunger / to release him.
Similarly in Fig. 2 a small plunger is fixed through the front plate of the box or
case A and when the screen B is turned from left to right from over the "Train
accepted" disc, it is caught and held by the catch D on the axis C by means of
When an electric
the catches e e¹ on the armature F of the releasing coils E E¹.
current is transmitted by the action of a train passing over the rail contact the
armature F is drawn down and releases D allowing the screen B to revolve over
again from right to left. In order to release the screen without a train passing
over the rail contact in consequence of the receipt of the cancelling signal or
through a train not having to go forward through the section in advance the
releasing lever H is manipulated by a small plunger pressing forward and this
engages with the armature F pulling it down just the same as if a current had
attracted it down to the magnet. At the same time lever H also engages with the
small cog-wheel I having on its periphery consecutive numbers from 1 to 20 or
other numbers as desired and moves these numbers forward one step that is one
number for each depression of the plunger operating the lever H. Thus every
time the screen B is manipulated other than by the current this index indicates the
fact by the number which stands for the time being in front of the small orifice of
the plate covering up the lower portion of the box or case A as more fully
described in my Specification No. 22093 of 1892.
.
The "Train accepted" discs shown in Figs. 1 and 2 are similar to an ordinary
drop indicator sometimes used for house bells. This "Train accepted" disc is
binged and is really a small flap shutter which can be raised up and is caught
and held up by the small spring catch u and it then shows the letters "Train
on line."
When the screen B is turned over from left to right there is a small
catch projection thereon which engages and raises the small spring catch u and
allows the "Train on line" disc or shutter to again fall forward over the red
plunger X disclosing the words "Train accepted "the object being to give a true
indication of the state of the signals forwarded. When the signalman wishes in
response to the "Train entering section" signal to give "Train on line" by means
of his red or "Train on line" plunger X he raises this small flap shutter or disc
"Train accepted" and it is again held up by the small spring catch u and discloses
the indication "Train on line" and the signalman immediately gives "Train on
line" by depressing the red plunger X and this fact is also indicated to him
electrically by the state of the lower needle of his block instrument.
to
unlock it
In Figs. 3, 4 & 5 I indicate by back view and sectional plans how I
propose
lock the white or "Line clear" plunger every time it is used and how
by the manipulation of the red or "Line blocked" plunger. And I also show how
the manipulation of the white or "Line clear" plunger brings into circuit a
separate or additional battery for the purpose of operating the electric lever locking
instrument at the station in the rear. Fig. 6 also shows in simple form the circuit
arrangement for the extra battery and how it is switched in by the plunging of the
white or "Line clear" plunger. Fig. 3 is a section looking from the right hand
side of the instrument and Fig. 4 is a section looking from the left hand side of the
instrument. In Fig. 5 A indicates the piston of the white or "Line clear
plunger and B the piston of the red or "Train on line "plunger each of which
carries on their inside ends the projections or engaging pieces C C¹ and the white
plunger also carries a small projection D (Figs. 4 & 5) and the red plunger
(piston B) carries a pin E (Figs. 3 & 5). The locking bolt or latch F (Figs. 3, 4
& 5) has its axis at G and carries a bevelled catch piece H upon a small spring I
attached to the bolt or latch F. J (Figs. 3, 4 & 5) is the key or spring catch
arrangement equivalent to a Morse key and which when manipulated by plunging
the "Line clear" plunger joins up the extra battery and also disengages the
"

page_text: "
catch K which it carries and allows the bolt or latch F to fall on to the piston. of
the white or "Line clear" plunger and as the latter comes back to its normal
position the latch falls into a slot or over a projection of the same and locks it,
i.e. the "Line clear plunger. The piston rod in addition to carrying the
projection or engager C C also carries a projection L (Fig. 5) for the purpose of
engaging and pushing back the spring J out of contact with the contact piece M
into contact with the contact point N which are of course fixed to insulating bosses
or brackets the N contact point being attached by means of the screw adjustment O
so that the movement of the spring J may be made to suit the movements of the
"Line clear" plunger.
The operation is this, when the "Line clear" plunger is depressed the piston A
(when the apparatus is in the normal position as shown in Fig. 5) is pressed
forward and carries with it the spring J out of contact with contact M into contact
with contact piece N and at the same time the latch F falls on to the piston rod A
as the catch piece K on J is moved from underneath the catch piece H on the
small spring on the bolt or latch F.
When the spring J is in contact with M the extra battery is switched into
circuit with the ordinary battery and when the projection C therefore reaches and
depresses the line spring in the instrument the full force of the two batteries is
transmitted to line to unlock the lever locking instrument at the station in the rear
and also actuates the block instrument needles at both ends. As the piston recedes
back the bolt or latch arrangement drops into the slot or from off the projection D
in front of D and thus prevents the white or "Line clear" plunger being again
operated until F is raised out of the way and again held up by the catch K on the
spring J. This bolt or latch F is raised into this position by the manipulation of
the red or "Train on line plunger (which only transmits the ordinary battery
current sufficient for the block but not for the lock) the pin E on the piston of
which engages with the rocking lever P which has its axis at R and by depressing
the small arm S raises a corresponding arm T underneath the latch F on to the top
of the catch K on spring J. Catch K and catch H (on the spring I on the latch F)
are bevelled to coincide so that the raising of latch F presses back the spring Ja
little until the catch H is above the catch K when the spring snaps forward again
and holds up the latch or bolt F ready to be released again on the manipulation of
the white or "Line clear" plunger. V (Figs. 3, 4 & 5) is the inner portion of the
lower plunger a shown in Fig. 1 and carries projection W to reach the line spring
inside the instrument.
In Fig. 6 X is the extra battery and Y the ordinary battery. Z and C corre-
spond with the zinc and carbon terminals of an ordinary Tyers double line block
instrument.
"
Fig. 7 indicates another form of Tyers double line single wire block instrument
where there is only one plunger the direction of the current being varied whether
for Line clear or "Line blocked" by means of a commutator the movements of
which I propose to control and which is shown in Fig. 6 and described in my
Specification No. 22093 of 1892. It is here again indicated for the purpose of
showing the special releasing device to release the commutator without the
manipulation of the starting signal lever and to indicate the extra battery arrange-
ment for the electric locking instrument.
In turning the commutator from left to right ready for giving "Line clear" the
spring catch raising device S on the circular disc A catches underneath the pin or
projection T on the lever U and as T rides on S the lever U is raised out of
contact with the contact point V into connection with the. contact point W thus '
joining the extra battery X to the ordinary battery Y. The pin or projection T is
really on the other side of the lever U.
Now when the plunger B is plunged the commutator is carried forward to make
the necessary connections to send the current and this circular disc A being a part
of the same is also carried forward in the act of plunging and the inclined catch S
is therefore pushed away from the pin T and the lever U after this is plunged drops

page_text: into the position shown in the drawing out of contact with the contact point W into
contact with the contact piece V. Therefore the extra battery X is only in circuit
for the first plunge in sending "Line clear" in order to manipulate the electric lock
at the signal box in the rear.
In
The lever a having its axis at b and with its projection c carries a tail piece with
a knob or handle d for the purpose of mechanically unlocking the commutator.
moving the knob or handle d from left to right this lever a is moved from right to
left and engaging with the pin or projection e on the lever C raises this lever C the
same as if manipulated by the signal lever and at the same time it moves forward
the index wheel one step indicating that the commutator has been unlocked
mechanically by means of this lever instead of by the sigual lever.
The form of electric locking instrument preferred is indicated by Fig. 5 and
described in my Specification No. 22093 of 1892 and which it is therefore
unnecessary to reintroduce.
It is of course understood that the meaning of single wire double line block
instruments in the letter press and claims as used does not exclude from the scope
of the present invention apparatus being used with two wires instead of one wire
and earth return or such an instrument with one wire for up line and one for down
line with returns for each.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
:-
Firstly. In a Tyers or other single wire double line block instrument for the
section in the rear wherein the use of the keys, commutators, or plungers for the
Line clear and Line blocked etc. indications are controlled by a screen or screen and
disc arrangement, which in its or their turn is or are controlled by the lever of the
starting or other controlling signal for the section in advance in combination with
the special mechanical releasing device with or without index or recorder of its use
to release the said screen without the manipulation of the signal lever or the rail
contact as the case may be substantially as, and for the purpose set forth and
described.
Secondly. In or with such a block instrument having interlocked screen or screen
and disc arrangement or equivalent device for controlling the use of the keys, com-
mutators, or plungers as set forth the combination of the special locking of the Line
clear plunger for each plunge of the same and the unlocking thereof by the
manipulation of the Line blocked plunger in the act of giving the Line blocked
indication to the station in the rear for the purpose and in the manner substantially
as set forth and described.
Thirdly. In a Tyers or other single wire double line block instrument with screen
and disc arrangement or equivalent device or the locking device for locking the
white or Line clear plunger up at every plunge as set forth or both together in
combination with the extra battery key or commutator for bringing into circuit
extra battery power when plunging the Line clear plunger to actuate the electric
lock controlling the use of the lever of the controlling signal for the entrance to the
section in the rear as set forth and described.
Fourthly. The combination of the several parts to make up the complete
apparatus of the several kinds substantially in the manner and for the purpose set
forth and described.
Dated this 20th day of December 1893.
FREDERICK T. HOLLINS.