Improvements in Look and Block Apparatus for Railway Signalling.
Year: 1895

page_text: Date of. Application, 11th Nov., 1895
omplete Specification Left, 3rd Feb., 1856-Accepted, 28th Mar., 1896
PROVISIONAL SPECIFICATION.
Improvements in Look and Block Apparatus for Railway
Signalling.
I, ARTHUR GEORGE EVANS, of 116 Palace Chambers, Westminster, in the
County of Middlesex, Civil Engineer, do hereby deolare the nature of this
invention to be as follows:-
In lock & block systems for railway signalling hitherto perfected the main object
to be attained has been that, when a train has ouce passed the starting or sectional
signal at section say A it shall not be possible for another to pass the same starting
or sectional signal until the first train has either passed the starting signal at
section, say B, or has been shunted clear of the line at B's section. In other
words it is provided that there shall never be more than one train in a section, that
is, between the starter at A and the starter at B.
Where there is only passenger traffic to be dealt with this is what is generally
needed, but on lines where not only passenger traffic is worked but where the goods
traffic is also heavy what is known as "permissive" working is permitted,―my
system of lock & block is designed and arranged for effectually safeguarding this
permissive system of working.
_
The main reason why the lock & block systems hitherto perfected have not
been more generally adopted is due to the fact that the various systems have held
the goods traffic back in the same way as they have held the passenger trains back,-
that is, "permissive" working has not been possible under their protection. In the
new block regulations issued by the Board of Trade there is a clause which provides
the following:-
-
a
"When a train starting at A is once within cover of the home signal at B,
B may give Line clear' to A and accept another train up to his home
signal."
This clause is now in operation on most of the railways and it is carried out
as follows at the present time:-
B accepts train No. 1 from A and as soon as the train has passed B's 'home
signal, he necepts another, first of all intimating to A that he is accepting
No. 2 train on the "permissive" system. A then gives the driver of No. 2 train
a verbal intimation that he is going into the section in advance on the
"permissive" system. It will be obvious that by working under this clause of
the regulations the traffic is considerably expedited and it is with the object of
maintaining this expedition with safety that my invention has been designed.
Briefly, the objections to working on the "permissive" system as above described
are as follows:-
1. That a communication is required to be made between B and A and this
communication may be misunderstood. 2. That A has to stop the train and
verbally instruct the driver that he is proceeding into the next section on the
permissive" system.
66
With my invention I do away with the necessity of B communicating with A and
of A communicating with the driver verbally; the way the invention is carried
out being as follows:-
Taking a section (for example). A and B worked by the single needle three wire
block system and the ordinary interlocking system,-I fix an electric switch in

page_text: connection with. B's sending instrument to which is attached two flags one
"absolute" and one "permissive." These flags appear alternately or as required
in an aperture cut in the dial of the instrument, this switch controls the working
and when it is in the normal position of absolute B can release A's "absolute
starter only. When it has been turned to "permissive'
"
B can release
A's "permissive" starter only. When onco B has accepted an "absolute" train
the switch is locked by a mechanical device connected with the home signal so
that B cannot accept another "absolute "train until he has first pulled and put
back his starting signal lever.
This electric switch and mechanical device combined give B sole control over
A's starting signal and A can only send the train on to B as B requires it,
viz., "absolute or "permissive." At A I fix an additional arm and light of a
special design underneath the ordinary starting arm or in any other suitable
position. The ordinary starting signal arm would be used for "absolute" trains
and the specially designed arm for "permissive" trains. The driver would thus
have it clearly indicated to bim as to whether he was proceeding into the section
ahead on the "absolute" or "permissive".system.
"
Any of the well known systems of lever saving gear may be employed by which
one lever may work both the absolute and "permissive" starting arms and in
connection with such apparatus an electric lock is so arranged that when in its
normal position it locks both the "absolute" and "permissive" signals so that the
sigualman at A cannot pull the signal lever until B sends a current to take the lock
out of either the "absolute
or "permissive" signal connections, and B can only
take the lock out when he has his switch set either to "absolute" or "permissive
and then he can only take out the particular lock for which his electric switch is
set. The following description illustrates the mode of working traffic on this system,
the first traiu being dealt with on the "absolute" and the second on the "permissivo":
system.
A asks B to accept a train,--B has his electric switch in its normal position and
the flng lettered "absolute" is displayed on the dial of his instrument. B now
pegs over the needle of his instrument to "Line clear" and in so doing sends a
current into the lock circuit at A, draws the absolute lock and releases the
"absolute "starter, this is for No. 1 train.
So long as Line clear signal is appearing the lock would be released, but by a
special electrical and mechanical device the lock circuit is broken down and is only
joined up when "Train on line" is given by B. It will be understood that this
arrangement prevents the starter being pulled a second time with the same "Line
clear" signal, and compels the sending on of "Train on line." This is a special
feature and I claim to accomplish it at a very small cost to relative to what its
accomplishment has cost in other systems. No. 1 train having arrived within the
protection of B's home signal B can now take a "permissive" train; he could not
take an
"absolute" train as already explained. B. turns his switch to permissive
and send a current which takes out the "permissive" lock at A and A can then
pull the "permissive" starter and the "permissive" starter only. This indicates
to the driver "Section clear but station blocked." This system would be
advantageous in case of working trains into bay or terminal lines as it could be
arranged that if the points were pulled over for the bay the "permissive"
or specially designed arm could only be given for such line.
In connection with my invention as herein described I could also arrange for
recording apparatus if necessary to record when "permissive" signals have been
given and when "absolute "signals have been given either at A or B.
Dated this 11th day of November 1895.

page_text: COMPLETE SPECIFICATION.
Improvements in Lock and Block Apparatus for Railway
Signalling.
I, ARTHUR GEORGE EVANS, of 116 Palace Chambers, 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 :-
In the present lock & block systems for railway signalling the main object
attained is that when a train has ouce passed the starting or sectional signal at
section, say A, it shall not be possible for another to pass the same starting or
sectional signal until the first train bas either passed the starting signal at section,
say B, or has been shunted clear of the line at B's section. In other words it is
provided that there shall never be more than one train in a section, that is, between
the starting signal at A and the starting signal at B.
This result is satisfactory where there is only passenger traffic to be dealt with,
but on lines where not ouly passenger traffic is worked but where the goods traffic
is also heavy, what is known as "permissive" working is permitted. My invention
is designed and arranged for safeguarding this permissive system of working, as
well as giving the necessary safety when the "absolute" system is worked.
The main defect or inconvenience in the employment of the majority of the
present systems of lock & block working is that the goods traffic has been held
back in the same way as the passenger traffic, that is, "permissive" working has
not been possible under their protection.
In the new block regulations issued by the railway companies early in the
year 1895 there is a provision to the following effect :-
"When a train starting at A is once within cover of the home signal at B,
B may give Section clear but junction blocked' to A and accopt another train up
to his home signal."
This is carried out in the following manner :-
B accepts train No. 1 from A and as soon as the train has passed B's home
signal he accepts another, first of all intimating to A that he is accepting No. 2 train
on the "permissive" system. A then gives the driver of No. 2 train a verbal
intimation that he is going into the section in advance on the "permissive" block.
It will be obvious that by working under this part of the block instructions the
traffic is considerably expedited and it is with the object of maintaining this
expedition with safety that my invention has been designed.
Briefly, the objections to working on the "permissive" system as above desoribed
are as follows :-
1. That a bell, telephone, or telegraphic communication is required to be made
between B and A and this communication may be misunderstood.
2. That A has to stop the train and verbally instruct the driver that he is
proceeding into the next section on the "permissivo" system.
3. That in the event of a train having passed the signal box, and being brought
to a stand at the starting signal or the advanced starting signal, the driver must
understand that the lowering of the starting signal is an indication that the line is
only clear to the home signal at the signal box in advance.
With my invention I avoid the necessity of B communicating with A, and
of A communicating with the driver verbally, and I give the driver a distinctive
signal by means of a specially designed arm to indicate that he is going into the
section under the "Section clear but station or junction blocked" instructions.
The way in which I carry out my invention is as follows:-
Taking a section, for example between A and B, worked by the single needle
three wire block system and the ordinary interlocking system,-I fix an electric

page_text: 66
or
switch in connection with B's receiving instrument to which is attached two flags or
indicators, one bearing the word "absolute" and the other "permissive
goods." These flags appear alternately or as required in an aperture cut in the
dial of the block instrument. The aforesaid switch controls the working and when
it is in the normal position of "absolute" B can release A's "absolute" starting
or sectional signal only. When it has been turned to "permissive" B can release
A's "permissive" sigual only. When once B has accepted an "absolute" train the
switch is locked by a mechanical device connected with the home signal lever so
that B cannot accept another "absolute or passenger train until he has first
pulled and put back his starting signal lever.
"
This electric switch and mechanical device combined give B sole control over
A's starting signals and A can only send the train on to B as B requires it, viz.,
"absolute" or passenger, or "permissive," or goods. At AI fix an additional
arm and light, preferably of a special design and colour, underneath the ordinary
, starting signal arm, or in any other suitable position. The ordinary starting signal
arm would be used for "absolute or passenger trains and the specially designed
arm for "permissive" or goods trains. The driver would thus have it clearly
indicated to him as to whether he was proceeding into the section ahead on the
"absolute "permissive" system.
"
or
"
'
Any of the well known systems of lever saving gear may be employed by which
one lever may work both the "absolute" and "permissive" starting signal arms
and in connection with such apparatus a lock is so arranged that when in its
normal position it locks both the "absolute" or passenger and "permissive" or
goods siguals so that the signalman at A cannot pull the signal lever or move
either the "absolute " or passenger, or "permissive" or goods signal to the
'safety" attitude until B sends a current to take the lock out of either the
"absolute" or passenger, or "permissive or goods signal connections, and B can,
only take the lock out when he has his switch set either to "absolute" or "passenger,"
or "permissive" or "goods" and then he can only take out the particular lock for
which the electric switch is set.
66
"
"
In order that my invention may be better understood and more readily carried
into effect I will proceed to describe the drawings hereunto annexed.
Sheet 1, illustrates principally the mechanical details at cabin A. In this
sheet are also shown, but not in detail, the electric controller fixed in front of
the interlocking machine adjacent to the tappet, and the electric lock below the
nachine and adjacent to the lever saving appliance, that is, to the two connections
leading to the absolute" starting signal arm and the "permissive." starting signal
.arm at A.
"
Figure 1 illustrates a side view of the interlooking machine showing the lever
saving appliance by which one starting signal lever operates two starting signals,
that is, the "absolute starting signal or the "permissive" starting signal.
A connection is also shown from the "permissive" starting or right hand blade
of the lever saving appliance by means of which the distant signal, which should
be released by the "absolute" starting signal, is locked when the "permissive"
starting signal is given. The arrangement of downright rod actuated by the
movement of the catch-handle is also shown, by which one or other of the cross
locks of the lever saving appliance is released according as sanction is given by
the cabin in advance, say B, as to whether "absolute" or "perinissive" sanction
is to be given to A; by this is meant, as to whether the "absolute" or "permissive."
starting signal is to be lowered.
Figure 2 is a back view of Figure 1.
Figure 3 is a part front view of Figure 1, in order that another view of the
electric lock controller may be obtained.
Sheet 2, illustrates enlarged details of the electrical parts shown in Figure 1.
Figure 4 is a front elevation of the electric look.
Figure 5 is a plan of Figure 4 illustrating that the blades are normally locked
which release either the "permissive" or "absolute" starting signal at A.

page_text: Figure 6 is an enlarged view of the electric lock controller shown in Figure 1
above the locking trough in the front of the interlocking machine, adjacent to the
starting signal tappet.
Figure 7 is a plan of Figure 6.
Sheet 3 show's enlarged views of the relay at A, situated on the instrument
shelf or at any convenient spot in the sigual cabin. It also shows an elevation of
the starting and distant signal arms with the "permissive" starting signal arm
intermediate between the two. A diagram of three complete sections is also
shown.
Figure 8 is a plan of the relay nt A.
.1
Figure 9. is a sectional elevation H-J of Figure 8 to show the armature, and
spring.
Figure 10 is a front elevation of Figure 8.
Figure 11 is a front view showing the "absolute" and "permissive" starting
signals with the distant signal blade beneath the latter.
"
Figure 12 is a diagram of Up and Down roads showing the "absolute" and
"permissive" starting and home signals for three sections, A. to B, Bito C and
C to D. The distant signals are omitted from this diagram. They have no
particular reference to my invention except in so far that the "permissive
starting signal blade on being moved upwards locks the distant signal in relation
to it, that is to say, that both cannot be at the "safety" attitude at the same time.
Sheet 4 illustrates the mechanical details at cabin B, that is, the cabin in advance
which gives the sanction to A to send trains.
Figure 13 is a side view of the interlocking machine showing the upright con-.
nection (operated from the home signal tappet) to the block instrument.
Figure 14 is a back view of Figure 13.
Figure 15 is a plan of the interlocking trough with the cover removed showing
the home and starting signal tappets attached to the respective home and starting
signal levers, by the operation of which movement is given to the upright rod to
effect certain movements in the block instruments.
Figure 16 is a front sectional elevation of Figure 15.
Sheet 5 shows enlarged details of the electrical and mechanical connections in.
the block instrument at B.
'
Figure 17 is a front view of an ordinary block instrument showing the addition
which comprises part of my invention in the shape of a switch, and the dial with.
the word "absolute" showing.
Figure 18 is a back view of Figure 17 showing the relay at the top of the.
instrument and the mechanical details worked by the home signal lever in the lower
part of the instrument.
Figure 19´is a side view of Figures 17 and 18 with the wooden cover of the
instrument removed illustrating, my special switch, and a side view of the relay at.
the back of the instrument, together with the mechanical connections as shown in
front view Figure 18..
Figure 20 is a plan on top of Figure 19.
Sheet 6 illustrates further details of the electrical connections of the block.
instrument at B together with the mechanical operation, by means of my special
switch, of the flags or indicators "absolute" and "permissive."
Figure 21 is a front elevation partly in section on line K-L Figure 20, of the
block instrument at B, practically showing the front part of the instrument taken
away, that is, the handle and cover, illustrating the mechanical operation of the
Hags or indicators "absolute" and "permissive."
7
Figure 22 is a plan on top of Figure 21, but with the addition of my Bwitch.
handle.
"
Figure 23 shows the mechanical details (separately) of the operation by the
cam of the flags or indicators "absolute". or.permissive." The "permissive
indicator is always normal, that is, to say, in a fixed position. It is the "absolute
indicator which is either moved above the aperture in the dial, allowing the word:
"

page_text: "permissive to be shown, or moved down to show "absolute," obstructing the
indication of "permissive."
In Figure 23 the "absolute" indicator is shown as worked, that is to say, that
were the wooden case of the instrument in its place the word "permissive" would
be showing.
•
Figure 24 is a plan of the electric connection springs underneath the barrel or
handle of the instrument, as shown in Figure 21.
In Sheet 7, Figure 25 is a general diagram of the electrical connections at
cabins A and B, showing the flow of the current and the working of the electric
locks and block instruments.
The same numbers refer to the same parts in the several figures of the
drawings:-
"
"
or
"
1 is the starting sigual lever at A operating both the "absolute" and "per-
missive" starting signals according as the sanction is given by B.; 2 is the starting
sigual tappet; 3 is a pin or projection.on the edge of the starting signal tappet;
4 is the catch rod of lever 1; 5 is a pin or projection in the side of the drop
box 6; 7 is an upright rod curved at the top, normally supported vertically by the
pin; 8 is a side projection on 7 normally in the notch 9 of a blade 10 fulcrumed
to the lever 1; 11 is a downright rod from the end of 7 to a sway beam or floating
lever 12; 13 and 15 are releasing blades which release by the bevels 14 (Fig. 2)
the blades 17 and 18 according as the releasing bolts 19 or 20 are moved free of
the blades 17 or 18. The blade 17 goes to the "permissive" starting signal arm
at A. and the blade 18 to the "absolute" starting signal arm at A. 21 are links
connecting the tail of the lever 1 to a draft wheel 22 which operates, by chain,
either one or other of the blades 17 or 18 and through them the "absolute "
"permissive" starting signals at A. 23 is a connecting rod from the "permissive
starting signal releasing blade 13 to a cross bar fulcrumed in the casting of the
interlocking machine which works another cross bar also fulcrumed to the side of
the interlocking machine, this latter operating a bolt 24 which when the per-
missive"
starting signal is lowered to the "safety" attitude projects through a
hole in the tappet attached to the distant signal lever at A preventing the distant
signal from being moved to the "safety" attitude when the "permissive" starting
Bignal has been lowered to the "safety" attitude. Correspondingly, should the
distant signal lever be moved over to lower the distant signal to the "enfety"
attitude it prevents the movement of the "permissive starting signal by
obstructing the passage of the bolt through the tappet. 25, 26 (Fig. 6) are a pair
of electro-magnets; 27 is an armature fulcrumed at 28, attached to which is a
spring 29. The end of the armature 27 is formed into a pawl 30; 31 is a pin
preventing the armature from moving further to the right. 32, 33 are springs
normally in contact with contact pieco 34; 35 is an insulated pin to control the
upward movement of springs 32 and 33. 36, 37 are springs above the lever 38
which is fulcrumed at 39; the springs 36, 37 are normally disconnected from
contact piece 40; 41 is a stop to prevent the fall of lever 38; 42 is the upper arm
of lever 38 and 43 is the lower arm; this arm is formed in two pieces fulcrumed
at 44, acting that while a forward movement of the tappet 2 makes the arın 43
rigid, thrusting upward the arm 42, yet in the return throw of the tappet 2 the
lower piece 45 of the arm 43 is moved aside and does not operate the upper arm.
46 is a bracket by means of which the electric lock controller (Fig. 6) is fastened
to the interlocking machine; 47 and 48 (Fig. 4) are one pair of electro-maguets
and 49 and 50 are another pair of electro-magnets; 51 is a lock centred between
the two pairs of magnets, normally hanging in the middle position equidistant
between the two. The lock 51 is fulcrumed at 52; armature-plates 53 and 54 are
attached, one on either side of the lock 51. 55 is a notch in bolt 20 shown in
Fig. 1, and 56 is a corresponding notch in bolt 19. 13 and 15 are the blades
passing through slots in 19 and 20. 57, 58 (Figs. 8, 9 & 10). are a pair of electro-
magnets of the relay at A; 59 and 60 are side arms or cores projecting from the
magnets 57 and 58; 61 is an armature or needle. fulcrumed at 62, operated when

page_text: the magnets are energized either to the right or left towards the coros 59 or 60.
63 is a spring armature normally out of contact with contact piece 64, but when
the magnets 57 and 58 are energized the spring armature 63 is attracted down-
warde, making contact with contact piece 64. The spring is normally in contact
with contact piece 65. 66 and 67 are contact screws, contact being made with
either according to the movement of the armature or needle 61. 68 is the
"absolute "starting signal arm; 69 is the "permissive" starting signal arm; 70 is
an ordinary distant signal arm. 71 and 72 are the "absolute" and "permissivo "
starting signals at section say A; 73 is the home signal at section say B; 74, 75
are the "absolute" and "permissive" starting signals at section say B 76. is
the home signal at section say C; 77, 78 are the "absolute" and "permissive"
starting signals at section say C, and 79 is the home signal at section say D; 80
and 81 are the "absolute" and "permissive" starting signals at section say D.
82 is the home signal lever at the section in advance, say B (Fig. 13); 83 is the
tappet of home signal lever 82 (see Fig. 15); 84 is the normal position notch and
85 the pulled over position notch of home signal lever tappet 83; 86 is the starting
signal lever tappet at section B; 87 is the normal position notch and 88 the pulled
over position notch in the tappet 86 of the starting signal lever at B; 89 is a
bevel on tappet 83 and 90 a bevel on tappet 86. 91 is a connecting slide working
in the locking trough 92; 93 is a lock connected to the slide 91, (the lock is
bevelled on its top side) working in connection with the notches 84 and 85 in the
home signal lever tappet 83; 94 is a lock also connected to slide 91, working in
connection with the notches 87 and 88 in the starting signal lever tappet 86 at
cabin B; 95 is a raised bevelled block, also attached to the connecting slide 91.
A lever 96 is fulcrumed at 97 to a bracket attached to the locking box; a friction
roller 98 is attached to the lever 96; attached to the end of the lever 96 is an
upright rod 99; this upright rod terminates and acts as a blade 100, Fig. 13.
The blade 100 moves through and is kept in position by a bracket 101; fastened
also to this blade 100 is a click or pawl 102 (Fig. 18) fulcrumed at 103; 104 is a
pin to prevent the fall of the click or pawl 102; 105 is a lever at the back of tlie
block instrument keyed to the special switch; 106 is a pin on the lever 105 by
means of which the lever 105 is thrust upward by the blade 100. 107 is a quadrant
keyed to the spindle 108 of the block instrument handle 109; 110 is a pawl
normally out of gear with a notch 111 in the quadrant 107; the pawl 110 is
fulcrumed at 112. The pawl 110 terminates on the right hand side (back view.
of the instrument) in a projection 113; 114 is a shoulder on the pawl 110 normally
preventing the weighted pawl 115 from moving out of its normal position, that is;
dropping 115 is fulcrumed at 116 and terminates in a projection 117; 118 is a
click fulcrumed to the quadrant 107 the long arm of which is normally in gear or
preventing the forward movement of the weighted pawl 115; 119 is a pin main-
taining the long arm of the click 118 in a rigid position. 120, 121 are a pair of
electro-magnets in the relay at the back of the instrument at B; 122 is an
armature, and 123 and 124 are contact pieces; 125 is the handle of the special
switch; 126 is the spindle. 127, 129, 131, 133, 135, 137 and 139 (Fig. 25) are
contact springs normally in contact with contact pieces 128, 130, 138 and 140
respectively. When my special switch is moved over to the "permissive" position
contact is made between certain springs and contact pieces 128, 130, 132, 134, 136,
138 and 140. 141 is a terminal for connection for the current to flow through
spring 142 when the latter is in contact; 143 is a terminal for the current to flow
through spring 144 when in contact; 145 is an intermediate spring operated by
the movement of the block instrument handle into contact with terminal 146.
The working of my invention is as follows:-
.
Both signals at A, that is, the "absolute" and "permissive". starting signals,
are at "danger." Normally A cannot lower either of these by his own
lever 1. Permission is asked in the usual manner by A to send a train to B, and
B determines whether it shall be a "permissive" or "absolute " train,

page_text: In order to fully explain my invention I will work two trains, say between A
and B boxes, one absolute" and one "permissive'
A offers B a train. B accepts the same on the "absolute" system, and his
switch being in its normal position of "absolute " B pegs over the handle 109 of
his block instrument to "Line clear"; this action gives. "Line clear" signal on
his own and A's block instrument dials, and releases the "absolute" lock on A in
the following manuer:-The switch 125 has seven contact springs, 127, 129, 131;
133, 135, 137 and 139 which work on brass stud contact pieces 128, 130, 132, 134,
136, 138 and 140 fitted in the insulated ebonite barrel 147 to which the handle 125
is attached through the spindle 126; a current from four Leclanche.cells at 148
(which are for working the "absolute" system) will flow by means of wires 218
from the copper end of the battery 149 to spring 127 in the switch 125, through
the connecting piece 128 and connecting wire to contact piece 130, thence through
spring 129, through wire 204, through connecting block or terminal 141 in the
block instrument at B, from thence along the wire 205 to the terminal 150, thence
to the brass upright 151 which holds the battery springs 152, 153, and along the
battery stud 154 and barrel 155 of the instrument handle 109 to line spring 156, to
the terminal 157, thence along the line wire 158 to the block instrument at A,
through the usual coils 159, 100, along the wire 161 to the coils 57 and 58 of the
relay at A, along the wire 162 back again to the cabin at B on to the contact
spring 139 of the switch 125, from thence to the contact stud' 140, along the wire
to contact stud 138, through contact spring 137 along wire 225 to terminal 163,
thence along the wire 164 through the block coils 165, 166, to wire 167, line
spring 168 and through the insulated battery stud 169, along the wire 170 to the
terminal 171, along the wire 172 to the zine end of the battery 173. This "Line
clear"
current actuates the tongue 61 of the relay at A and releases the lock 51
by moving it to free the "absoluto " starting signal at A in the following
manner: The zinc end 174 of the battery 175 (at A) being connected by the
wire 176 to the contact spring 32 (Figs. 6 & 7) which rests normally on the contact
piece 34, the current flows through the connecting contact piece 34, thence to
contact spring 33, thence through the wire 177 to the contact screw 178 in the relay
(at A), through the tongue 61 of the relay, through the spring armature 63 to
contact stud 65, thence through the wire 179 to terminal 180 in the electric lock,'
through lock coils 50 and 49, through wire 181 to terminal 182, along wire 183 to
the copper end 184 of the battery 175. The lock 51 is drawn towards the clectro-
magnets 49 and 50 and, on reference to Fig. 5, it will be seen that the lock
moving to the right locks the blade 19 aud releases the blade 20, allowing the
signalman at A by moving his catch-handle 4 to move up the blade 7 by the
connecting rod and move upward the blade 15, moving out the bolt 20 and
freeing the signal slide 18; meanwhile, the blade 19 is locked by the electric
lock 51 obstructing its passage and by this means the signal blade 17, which is the
"permissive" blade, is prevented from being moved. On lever 1 being moved
over, blade 10 moves under projection 8, and as the top of 7 becomes free of stud 5,
blade 10 maintains 7 and 11 in the upward or worked position until lever 1 is
returned normal when notch 9 allows 7 and 11 to drop normal and 7 to re-engage
with 5. The bolt 19 being through the blade 17 acts as a fulcrum and the
signalman in working over his lever moves up the draft wheel 22 and the whole
of the pull on the wire comes on the blade 18, which deflects the. " absolute "
starting signal to the "safety" attitude.
-
In moving the starting signal lever over, which I have just described, the pin.3
on the tappet 2 (Figs. 6 & 7) cones in contact with the lower arm 45 of the
Llever 38 and. thrusts upward the arm 42 until the pawl 30 comes underneath and
engages (as shown in dotted position) the upper arm 42 of the lever 38;
spring 29, immediately the pawl 30. is free, draws it underneath the arm 42 to
engage. By this movement of the lever 38 the local lock circuit is broken down
by the lever moving free of the springs 32, 33, but another circuit is joined up by.

page_text: the top springs 36 and 37 being joined through the contact piece 40. A now offers
"Train on line" to B by the ordinary bell instrument and B in accepting "Train
on line," moves his block instrument handle to that position and the current flows
to the line wire, indicates "Train on line" on his own and A's block instrument
dials and at the same time actuates the relay tongue 61 at cabin A, connects up
the local battery 185, current flowing from the copper end 186 along wire 187 to
terminal 188, through the coils 26 and 25, along the wire 189 to terminal 190 and
contact spring 37, along contact piece 40, through contact spring 36, along wire 191
to terminal 192, on to the relay tongue 61, contact screw 193 and the zinc end of
the battery 194, thus causing the armature 27 to be drawn up to the ends of the
coils 25, 26, and allows the L crank 38 to fall and disconnect the springs 36, 37,
and again connecting up the springs 32, 33. The electric lock 51 by this action falls
to the normal position when the starting signal lever 1 at cabin A is put back to
its normal position. On the return of the starting signal lever 1 at A the electric
lock controller is not effected, as the lower arm 45 of the lever 38 may be moved
without moving the upper arm 42 of this lever.
The signalman at B on moving his home signal to let the train pass, moves the
tappet 83 so that the bevelled pieco 89 slides over the lock 93 and the notch 85
falls around the lock 93. When now the home signal lever is returned to its
normal position the bevelled notch 85 thrusts aside the lock 93, moves the
connecting slide 91 so that the raised bevelled block 95 moving under the friction
roller 98 raises the upright rod 99 and through the end of 99, that is, blade 100,
acting on the pin 106, moves tlie lever 105 and as that is keyed to the electric
switch 125 moves the latter into the middle neutral (dotted) position 195 shown in
Fig. 17.
When B accepted "Train on line" from A he moved, the handle of his block
instrument into the "Train on line" position. Referring now to Fig. 18, the
quadrant 107 is keyed to the spindle 108 to which is attached the handle 109 of the
block instrument; therefore, when the handle was moved to peg the instrument to
"Train on line" position, the quadrant 107 was moved to the left (Fig. 18) so that
by gravity the pawl 110 could rise to lock the quadrant 107, thereby locking the
block instrument at B in the "Train on line' position. When now the home
signal lever is returned to the normal position and the action as hereinbefore
described takes place of blade 100 moving upward, the click or pawl 102 comes in
contact with the end 113 of the pawl 110, moves it upward and thrusts the other
end of 110 out of the quadrant 107; at the same time the shoulder 114 of the
pawl 110 is moved upward to free the forward movement of the pawl or weighted
lever 115, the balance weight falling when the top part 117 is moved forward and
cones in contact with the shoulder 114 locking 110 out, preventing it again falling
50 us to lock the quadrant 107. On the signalman at B returning his block
instrument from "Train on line" to the normal position, or to the opposite side,
that is the "Line clear" position, the long arm of the click or pawl 118 comes in
contact with the end 117 of the weighted pawl 115, thrusts back the latter to its
normal position and frees the pawl 110 ready so that if B gives sanction for
another train from A and pegs his instrument to "Train on line" again a similar
operation takes place as before described so that the block instrument at B is
locked in its "Train on line" position until the home signal at B has been pulled
over and put back again.
In the meantime, the return stroke of the home signal lever has locked my
special switch at B so that it cannot be moved to the "absolute" position again
until the starting signal at B bas been given for the train for which the home
signal was lowered to get into the station. When the starting signal has been
given and put to "Danger" again it may be assumed that, the train having got
clear of B's section, B should be in a position to accept a second train from A on
the absolute" system. As the forward movement of the starting signal tappet
(Fig. 15) is free through the bevelled piece 90 being allowed to move above the
lock 94 (it being understood that the home signal tappet having been moved has

page_text: thrust the look 94 into the notch 87), now on the return stroke of the starting
signal lever the notch 87 thrusts the lock 94 aside, operates the connecting
slide 91, moves the bevelled block 95 to the left and allows the, downright rod 99
¿to be returned to the normal position, as shown in Fig. 16. My special switch in
'the block instrument at B is now free, in as much as the blade 100 has moved
downward freeing the movement of the switch handle for another "absolute "
train..
г
But supposing the section ahead, say C, is not clear for B to send the first train
which has arrived, and he not wishing to bl ck A and keep the following train
there; he (B) is allowed to work on the "permissive" system. It must be
remembered that not having lowered his starting signal he cannot receive a secoud
train on the "absolute" system, because, having returned his home signal for the
first train to the "danger" position he has locked the special switch 125 of his
block instrument in the manner hereinbefore described, so that the switch cannot
bo moved to the "absolute" position.
Permissive working is effected in the following manner:
The signalman at B turns the handle of the special switch 125 to the right for
"permissive" sanction (shown in Fig. 25 as in position X), and indicates on the
dial of his own instrument the word "permissive." This movement of the switch
handle to the "permissive" position effectually prevents the lock 51 at A from
being moved to free the "absolute" starting signal. The movement of the switch
to the "permissive" position cuts out automatically the battery of four Leclanche
cells, 148, used for "absolute" working and switches in a battery of, say eight
cells, which is used for "permissive" working. When the special switch at B is
set to the "permissive" position, B can accept a train from A by giving "Line
clear" signal to A cabin. The working over of his block instrument handle to
that position which gives the indication "Line clear" at A, also indicates "Line
clear" in his own instrument at B: When the handle of the block instrument at B
is turned over to "Line clear" the insulated blocks 152 and 153 press down
spring 145 which is connected by means of connecting plate 146 with the eight cell
Leclanche battery 148 and 196. On spring 145 being pressed down the current
flows from the copper end 197 of the battery 148 & 196, along the wire 198 to the
connecting plate 146, along spring 145, along wire 199 to spring 131 and
switch 125, on to stud 132. by means of connecting wire to stud 134 and on to
spring 133, and by connecting wire 200 to the connecting block 201 of the relay,
through the coils 121 and 120 to the connecting block 202, thence along wire 203
to the terminal 171, along wire 172 to the zinc end of the battery 173. This
current going through the relay coils draws up the armature 122 and connects up
the line wire at 123. The line wire having been connected up by the above means
current flows from the copper end 197 of the battery of eight cells to the brass
connecting plate 146 placed underneath the block instrument barrel 155. The
handle of the block instrument now being held over to "Line clear" presses the
spring 145 which makes contact with the brass connecting plate 146 and the current
flows to spring 131 in the switch 125, to contact stud 132 along the wire to contact
stud 130, through the spring 129 in the switch 125, along the wire 204 to the
small connecting block 141, thence along the wire 205 to the terminal 150, through
the brass upright 151, through the spring 206-and battery stud 154, through the
barrel 155 to line spring 156; to the terminal 157, along the line wire 158 to A,
through the block coils 159 and 160, through the wire 161 to the coils 57 and 58,
from thence back along the wire 162 to the spring 139 in the switch 125 at cabin B,
to the contact stud 140, thence to contact stud 136, along the spring 135 to
connecting block 207, thence to the small connecting screw 123, along the
armature 122 to the connecting block 208, theuce to the connecting block 209,
along the wire 210 to the terminal 163 in the block instrument, also through the
block instraiment coils 165, 166 by wire 164, returning by wire 167 to the line
spring 168, through the insulated battery stud 169 to tho terminal 171, thence by
wire 172 to the zinc end 173 of the eight cell battery. The relay tongue 61 at

page_text: cabin A is pulled and held over by the "Line clear" current and makes contact
with the contact screw 67 and moves the lock 51 into the "absolute" release bolt,
freeing the "permissive" release bolt in the following manner :—
The current flows from the zinc end 174 of the local battery 175 through the
springs 32 and 33 fixed on the electric lock controller, exactly in the same manner
as when working on the "absolute" system, to the contact screw 67 by means of
the wire 177 through the tongue 61 of the relay, to the spring armature 63, to the
contact screw 64, by wire 211 to the terminal 212, thence through wire 213,
through coils 48 and 47 to terminal 214, and thence by wire 183 to the copper
end 184 of the battery 175. This action releases the "permissive" lock blade in
the lever saving appliance at A and allows the signalman, on moving his starting
signal lever, to operate the "permissive" starting signal. The movement of the
starting signal lever and the operation of the tappet performs precisely the same
action and movement as was performed when the lever moved for giving the
"absolute" starting signal, that is to say, the electric lock controller is broken
down.
On the train now starting from A, A offers "Train on line" signal to B,
B accepts and releases the handle of the block instrument from the "Line clear"
position; in doing so he disconnects the spring 145 in connection with contact
block or plate 146 in the block instrument and the eight cell battery 196 is cut out,
the armature 122 of the relay falls into its normal position and disconnects the line
at 123. B now pegs over the handle of the block instrument and connects up the
line wire and four.ordinary cells by means of the insulated block 152 on the barrel
of the block instrument handle, brings spring 144 in connection with connecting
plate 143. and spring 142 in connection with plate 141. The wire 216 from
spring 144 connects spring 139 in switch 125, and the wire 217 from connecting
plate 143 is connected to spring 137 in switch 125 and these connectious form part
of the line wire. The spring 142 is counected by wire 218 to the copper end 149
of the four cell battery 148, and the connecting plate 141 is connected by wire 205
to terminal 150. The "Train on line" current, consisting of four cells, will now
flow along the line wire through the block instrument in the usual way, actuating
the tongue 61 of the relay at cabin A, releasing the electric lock controller in the
manner described with reference to "absolute" working.
The mechanical working of the switch 125 displays "absolute" or "permissive'
indicatious in the aperture cut in the false plate or dial of the block instrument,'
The permissive" flag or indicator 219 (Figs. 21, 22 & 23) is stationary and has
no physical connection with the switch 125. A cain 220 is mounted on the
barrel 126 of the switch 125 and this works a brass foot 221 fitted to the
movable indicating, slide rod 222 to which is attached the flag or indicator 223
labelled "absolute,"
66
"
When the switch is in its. normal position the flag or indicator labelled
" absolute appears in front of the fixed and stationary indicator labelled
permissive," and when the switch 125 is turned to "permissive" the foot 221
moves on the .cam 220 and raises the sliding rod 222, causing the "absolute"
flag 223 to be raised above the aperture and the "permissive" flag 219 only to be
seen. Figure 33 illustrates the switch 125 moved to the " permissive" position
with the word "permissive" showing, that is, the flag "absolute " has been raised
above the aperture. When the oam is rotated and the foot 221 falls the flag
"absolute" falls in front of the flag "permissive."
66
I am aware that a signal arm which might be construed as partaking of a
permissive" nature has been used before as a signal to allow a train to draw up
to a platform and discharge its passengers or to perform shunting operations when
the section ahead was blocked, the train passing the ordinary signal in the
'Danger" attitude, but in such cases there was no electrical control from the
cabin in advance. I, therefore, do not, per se, claim the "permissive" arm, neither
do 1 claim the general idea of the man in advance, say B, electrically controlling

page_text: L
the levers operating the sectional signals in the rear section, say A, but what I do
claim is :-
1. An improved lock and block system operating that the section ahead, say B,
releases and determines as to whether the train leaving A shall enter into
B's section on the "absolute" or "permissive" block system, substantially as
herein set forth and described.
2. In a lock and block system, the provision of a separate outward indication or
or signal for trains leaving section, say A, on the "absolute" system, and again a
separate outward indication for trains leaving A on the "permissive" system, in
the direction of section, say B, such signals being controlled by the section in
advance, say B, so that when once the "absolute" sectional signal at A has been
lowered and replaced it cannot be again lowered to admit a second train to B until
the first train has either passed out of B's section in the direction of C or moved
clear of the line at B, substantially as herein set forth and described.
:
3. In a lock and block system arranging that the return stroke of the home
signal lever at the section in advance, say B, locks the block instrument (at B)
preventing a second train being received from the section in the rear ou the
"absolute system until the starting signal at B has been pulled over for the first
train to proceed out of the section and put back, all substantially as set forth and
described.
33.
4. In a lock and block system, the combination of a special switch mechanically
operating two flags or indicators labelled respectively "absolute" or "passenger."
and "permissive" or "goods," so that the movement of the switch in one direction,
say to the "permissive" position, will indicate on the dial of the block instrument
"permissive," and correspondingly the movement of the switch to the "absolute"
position will indicate the word "absolute " on the dial of the block instrument,
substantially as set forth and described.
5. In a lock and block system, the combination of a lever saving appliance or
levers or signal connections at the scction in the rear, say A, operated by one
sigual lever, the said lever saving appliance being directly controlled by the cabin
at the section in advance, say B, and according as B moves his special switch to the
"absolute " 46
ог permissive" positions so the "absolute" or "permissive" blades
in the lever saving appliance at A will be released, and on the common lever at A
being worked over will, through the lever saving appliance, lower either the
"absolute' or "permissive" starting or sectional signal, substantially as described.
"
Dated this 3rd day of Felix 108
JOHN P. O'DONNELL, Fel. Chart. Inst. P.A.,
70 and 71 Palace Chambers, Westminster, S.W.,
Agent for the said Applicant.