Improved Means for Signalling on Railways.
Year: 1893

page_text: Date of Application, 3rd Feb., 1893
· Complete Specification Left, 1st Nov., 1893-Accepted, 13th Jan., 1894
PROVISIONAL DIEVIFICATION
Improved Means for Signalling on Railways.
I HENRY GEORGE DALLIMORE of 316 Camberwell New Road in the County of
London Solicitor and Patent Agent do hereby declare the nature of this invention
to be as follows:-
This invention consists of a new or improved apparatus whereby a railway signal
may be placed or set at danger by pressure from the wheel of a passing engine,
independently of a signalman's intervention, and its object is to prevent accidents
resulting from the failure of a signalman by sudden illness or death or neglect of duty
to set a signal at danger after a train has passed a signal post.
The apparatus is of small size and may be covered over or enclosed in a box and
thereby preserved from the weather. It may be made wholly of iron, or partly of
iron and partly of wood, and is placed between the signal post, and the signal box,
but near to the signal post.
The apparatus is constructed as follows: Upon two suitable upright posts, or
standards, I set up a barrel or cylinder of suitable size, made of solid hard well
seasoned wood, or of iron bars laid over and bolted to iron rings.
On the under side of the cylinder I fix a pin which I call "the stop," projecting
from the cylinder.
On the upper side of the cylinder, furthest from the signal post, I affix a bar, of
suitable length, projecting from the cylinder, carrying a weight.
I also fix at suitable places on the cylindar two chains, or wire ropes, one of
which I carry over the top to the signal post, and make fast to the signal arm,
and the other of such chains, or ropes, I carry under the cylindar to the signal box.
On one end of the cylindar I place a bar of iron, oscillating on a spindle fixed
below the centre of the cylinder, and when hanging straight down towards the
ground, extending below the edge or circumference of the cylinder. This bar I call
the "adjusting bar.".
On one side of this adjusting bar I place a stop to hold it in position when
engaging the crosspiece hereinafter mentioned, and at a suitable distance 1 place
another stop to prevent it from swinging too far over in that direction as the cylinder
revolves.
66
At the side of the cylinder (opposite to that on which the weight is placed)
I set up a post of suitable size which I call the "slot-post "I cut a slot in this
post immediately opposite the stop, and place through it a bar, which I call the
stop-bar," one end being close to the stop, and the other end connected to the
This stop-bar is
ground lever hereinafter mentioned, by a suitable pin or spindle.
pivoted on the slot-post, or upon a bracket bolted to the slot-post, at such a point
as that when the arm running through the slot-post is raised a certain distance, the
end next the stop shall descend an equal or greater distance.
At the back of the stop (that is to say, on the side furthest from the stop-bar)
I set up a block of wood or iron, or other material, which I call the "stop-
block," its office being to prevent the cylinder from revolving more than a certain
distance either way.
I cut a second slot in the slot-post to the right of the slot carrying the stop-bar,
but somewhat lower. The lower surface of this slot is on the same level as the
lower side of the sigual end of the ground lever hereinafter mentioned. This
lower, or second, slot is so cut that it shall be opposite to the end of the cylinder.
.

page_text: Beyond the stop-block, but not on the same line, at a suitable' distance from the
slot-post I set up a smaller post, which I call the "spring-post," in which I cut a
slot of the same size and in the same line as the second-slot in the slot post. In or
through the last mentioned two slots I place a bar of hard wood or iron, of suitable
length and thickness. This bar I call the "spring bar." On this spring bar, near
to the stop, I affix a crosspiece extending upwards towards and terminating near the
cylinder. Behind this crosspiece, and between it and the spring-post, and round
the spring bar, I affix a spiral spring of strength sufficient in the absence of
resistance to cause the spring-bar to move quickly such a distance as will carry the
other, or further, end of it under the ground lever.
On the road, at right angles with, but below the level of the lines, or metals, on
which the railway-trains run, I-place-an-iron bar of suitable shape and length,
which I call the "ground-lever." This ground-lever is pivoted at or near the
middle, so that as one end is depressed a certain distance, the opposite end is
raised an equal or greater distance.
The other end of the ground-lever, (near the cylinder and which I call the
"signal end" of the ground-lever) is turned up and slotted, so as to enclose, or fit
over or round the outer end of the stop-bar, before mentioned. A spindle, or
pivot is inserted at this point, through the ground lever and the stop bar on which
the stop-bar may work.
· Below the signal end of the ground-lever is placed a block of wood or other
material, on which it rests until lifted, and on which the head of the spring-bar
rests when the lever at that point has been raised. This block I call the
"lever-rest."
On the rail end of the ground-lever I affix two flat bars of iron, one on each
side of the lever, which I call "pressure-bars," working at the ends furthest from
the ground lever, on a small knuckle, or in or between suitable guides; and I
place those ends with the knuckles, or guides, so far down as to be below the reach
of the flange of the engine wheel, and rising to a suitable point above the level
of the rail. These bars thus form inclined planes, and their ends over the ground-
lever, are so constructed as that when they are depressed to their lowest level
they close upon each other.
The apparatus hereinbefore described having been fitted and adjusted in the
manner before mentioned operates as follows:-
As a locomotive approaches, the flange of its front near wheel strikes the first
pressure bar, after it has passed over the knuckle or guides before mentioned, and
passing along the pressure bar, depresses it, and with it the rail end of the ground-
lever; and as it travels along the second pressure bar, it continues the depression
of the ground lever, while the second wheel of the engine is travelling over the
first pressure bar, and so on with each wheel on the near side of the engine and
tender, and the next following wheel. This depression of the ground lever causes
the signal end of such lever to rise, which thereupon carries up that end of the
stop-bar which is connected with the signal end of the ground-lever at the point
where the spindle is inserted, and depresses the other end of the stop-bar, and
thereby relieves the cylinder from its stopping, or negative, pressure. The
cylinder being then free to move is made to revolve, by means of the weight
herein before mentioned, a certain distance, until the weight descends to and is
stopped by the stop-block. As the cylinder describes an arc of a circle, it draws
the signal chain, or rope (which runs over the top of the cylinder) such a distance
as is sufficient to pull down the back of the signal arm thereby raising the arm
itself to the horizontal position which indicates danger to a succeeding train.
The same movement of the ground-lever in raising one end of the stop-bar,
also at the same moment releases the spring bar, the head of which had been
previously pressed against the lever by means of the spring at the other end of
On the signal end of the ground lever being lifted the spring at once thrusts
the spring bar forward, so, that the other end or head of it slides under the ground
lever, upon the lever rest, and thereby prevents the lever from returning to its
it.

page_text: level, or horizontal, position. This movement of the spring bar is taking place
whilst the engine and tender wheels are running over the pressure bars.
The signal is taken off, or placed at safety by the signalman drawing in the
second chain or rope before mentioned (viz. the chain or rope carried under the
cylinder to the signal box). This he may do by a lever, such as is now commonly
used in sigual boxes-or a cylinder, or a pulley over which the chain or rope is
run, so that the end may hang down from above the signalmans head and having
a small weight to keep it taut.
The operator by pulling in this chain, or rope, causes the cylinder to revolve
back to its original position as herein before described, viz. that position when the
stop is below the centre. This revolution at once releases the signal chain
(viz. the chain which, runs over the top of the cylinder) and causes it to recede
towards the signal post. The tension being thereby taken off the signal chain,
the signal arm is set free, and it at once descends to the diagonal position of
safety.
The same back movement of the cylinder causes the adjusting bar to engage the
crosspiece on the spring bar aud push it back against the spring. In doing so it
draws the head of the spring bar from below the end of the ground lever, which
thereupon returns to its original horizontal position.
At the moment when the spring bar is pushed back a sufficient distance to allow
the lever to return to its original position, the adjusting bar passes over the top of
the cross-piece, and sets it free from pressure. The spring bar is thereupon free to
move again when the next train passes.
When the spring bar has been thrust under the ground-lever, in manner before
mentioned, the crosspiece upon it is on one side of the adjusting bar, but it forms
no obstruction to the cylinder as it revolves, when setting the signal to danger,
because, as before mentioned, the adjusting bar swings on a spindle placed below
the centre of the cylinder. As the cylinder moves by the weight on its side the
adjusting bar is made (by contact with the crosspiece on the spring bar) to describe
an arc of a circle less than the circle described by the cylinder, and thus to slide
over the top of the crosspiece on the spring bar without obstruction.
When the operator has drawn in the chain or rope so far as to set the signal to
safety (and he cannot do more because the cylinder has gone back so far as to carry
the stop against the stop-block) he releases the chain, but does not make it fast, for
when the cylinder is set free by the passing engine, and is drawing up the signal
arm to danger, the cylinder is at the same time drawing back the chain or rope
from the signal box.
The weight carried on the cylinder is therefore made sufficiently heavy to be
able to overcome the resistance of the signal arm and the two chains combined.
The arrangement for sustaining the ground lever, when raised at the signal end,
and the spring bar itself may respectively be varied or modified, and the spring
may be dispensed with; other methods being adopted as alternative methods of
carrying out their several functions.
One modification is as follows viz. :-To make the spring bar of an irregular
shape, placed in a vertical position working on a spindle at the bottom, and having
a shoulder to fit over or engage the end of the stop bar under the cylinder, and an
inclined surface from the top downwards against which the end of the stop bar
travels as it descends, thereby pushing the spring bar back against the spring.
On the stop bar passing the angle made by the inclined surface and the shoulder
(which form two sides of a triangle) the spring thrusts the spring bar back to its
vertical position, whereby the shoulder at once engages the upper side of the stop
bar, and retains it in position until the signal is taken off.
Another method or modification is to affix to the signal end of the ground-lever
a bar of iron which I call the oscillating bar with a slot in it, working on a pin in
5 the ground-lever, and pivoted on to the slot post or on a bracket on the slot post,
with a cross bar on the same pivot or spindle, carrying at the lower end a projection
or foot, at such an angle as will place that projection of foot under the ground lever

page_text: as it is raised at the signal end, and there suspend the lever, and prevent it from
returning to its horizontal position. The spring bar in this case is irregular in
shape, having, like the spring bar in the last instance an inclined surface and a
shoulder, but it is pivoted on the slot post at such a point as will place the inclined
surface against the oscillating bar on the ground lever. As the signal end of the
ground lever rises it will raise one arm of the oscillating bar, and depress the other
arm against the inclined surface of the spring bar, and thereby thrust it back
against the spring until such oscillating bar passes the angle, when the spring bar
reverts to its normal position, but in so doing engages the end of the oscillating bar,
and so retains, the ground lever by suspension. The spring bar in this case is
drawn away from the oscillating bar by means of rods and oscillating levers in
shape somewhat like the letter V-fitted to the slot post, and operated upon by the
adjusting bar hereinbefore mentioned.
If the spring be dispensed with a weight may be used instead thereof, which will
cause the spring bar to slide forward when set free.
Dated this Third day of February One thousand eight hundred and ninety-
throo
COMPLETE SPECIFICATION.
Improved Means for Signalling on Railways.
I HENRY GEORGE DALLIMORE of 316 Camberwell New Road in the County 2
of London Solicitor and Patent Agent 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 consists of an improved apparatus whereby a railway signal may
be placed or set at danger by pressure from the wheel of a passing engine inde- 3
pendently of a signalman's intervention, and its object is to prevent accidents
resulting from the failure of a signalman, by sudden illness, or death, or neglect of
duty to set a signal at danger after a train has passed a signal post.
The apparatus is of small size and may be covered over or enclosed in a box and
thereby preserved from the weather.
It may be made wholly of iron, or partly of iron and partly of wood, and is placed
between the signal post and signal box but near to the signal post.
The dimensions hereinafter given are not absolute; they may be altered if
considered desirable: they are used in this Specification by way of illustration.
3
The drawings hereto annexed consist of seven figures and illustrate the invention 4
and modifications thereof.
Fig. 1. is a side view of the apparatus with one end of the "ground lever”
hereinafter mentioned.
Fig. II. shews the upper faces of the "pressure-bars" laid along side the train
line, and the "ground lever" from under the pressure bars to the apparatus shewn
in Fig. I.
Fig. III. is a, side view of the pressure bars.
The invention is shewn in Figs. I. II. & III.; the remaining figures illustrate
modifications of so much of the apparatus as is.shewn in Fig. I.
Figs. II and III are drawn out of proportion to the other figures, because the
difference between the length of the pressure bars and the size of the apparatus is
so great that it cannot be shewn on the drawings for want of space.

page_text: Fig. IV. is a side view of so much of the apparatus as is shewn in Fig. 1. with
vertical spring bar instead of the horizontal spring bar shewn in Fig. I.
Fig. V. is a side view of Fig. I having a weight to actuate the spring bar
nstead of a spring.
Fig. VI shews another modification of Fig. I.
Fig. VII contains views of certain details hereinafter explained.
The apparatus is constructed as follows; Upon and between two suitable
pright posts or standards (not shewn in the drawings) I set up a barrel or
ylinder, A Fig. I, of suitable size, and about 12 inches in length, the lower side
being about six to eight inches from the base. This cylinder may be made of
solid hard well seasoned wood, or of iron bars laid over and bolted to iron rings.
On the underside of the cylinder I fix a pin, which I call "the stop" B Fig. I,
of about one inch square projecting one inch from the cylinder.
On the upper side of the cylinder, furthest from the signal post, about seven or
eight inches or more from "the stop," I affix a bar of suitable length, projecting
several inches from the cylinder, carrying a weight C Fig. I.
I also fix at suitable places on the cylinder two chains or wire ropes, one of
which, D Fig. I, I carry over the top to the signal post, round a grooved wheel
and make fast to the signal arm, and the other of such chains or ropes, E Fig. I.,
I carry under the cylinder to the signal box.
On one end of the cylinder I place a bar of iron, F Fig. 1, oscillating on a
spindle fixed below the centre of the cylinder, and when hanging straight down
towards the ground, extending about one inch and a half below the edge or
circumference of the cylinder. This bar I call the "adjusting bar."
On one side of this adjusting bar I place a stop G Figs. I. and IV., to hold it in
position when engaging the cross piece hereinafter mentioned, and at a suitable
distance I place another stop H Figs. I. and IV., to prevent it from swinging too
far over in that direction, as the cylinder revolves.
33
on
At the side of the cylinder (opposite to that on which the weight is placed) I set
up a post J Figs. I, II, IV, V, and VI., of suitable size (about twelve or fifteen
inches in height, three or four inches thick and six or eight inches wide) which I
call the "slot post." I cut a slot in this post immediately opposite "the stop.
the cylinder, and place through it a bar, K Figs. I, II, IV, V, and VI, which I
call the "stop bar," fifteen inches long and one inch square, one end being close to
"the stop," and the other end about four or five inches from the outer side of the
"slot post," and connected to the ground lever hereinafter mentioned by a suitable
pin or spindle, T, Figs. I, IV, V, and VI. This "stop bar" is pivoted on the slot
post, or upon a bracket bolted to the slot post, at such a point as that when the arm
running through the slot post is raised a certain distance (about 2 inches) the end
next "the stop shall descend an equal, or greater, or lesser distance as may be
found necessary.
59
At the back of "the stop" (that is to say on the side furthest from the "stop
bar") I set up a block of wood, or iron, or other material, L, Figs. I, IV, V,
and VI, about two inches wide, and four inches deep at the top, the face next "the
5 stop" being a vertical surface, and the further side of it being an inclined surface,
which I call the "stop-block," its office being to prevent the cylinder from
revolving more than a certain distance either way as hereinafter explained.
I cut a second slot in the "slot post" to the right of the slot carrying the stop
bar, but somewhat lower. The lower surface of the slot is on the same level as the
0 lower side of the signal end S¹ Figs. I and V, of the ground lever, S Fig. II,
hereinafter mentioned. This lower or second slot is so cut that it shall be opposite
to the end of the cylinder Figs. 1 and V. Beyond the stop block L, Figs. 1,
and V, but not on the same line, at a suitable distance from the slot post I set up a
smaller post, which I call the "spring post," M Figs. I and V., in which I cut a
55 slot of the same size, and in the same line as the second slot in the "slot post.'
Below the second slot in the "slot post" I place a small wheel with a flat rim N,
Figs. I, and V, and below the slot in the "spring post" I place another small
27

page_text: wheel with a flat rim O, Figs. I and V. In or through the last mentioned two
slots, and upon the two small wheels, I place a bar of hard wood, or iron, P
Figs. I, II, and V, of suitable length, or thickness, (about 22 inches long, and
one inch square), having a head next the ground lever as shewn at P' Figs. I and V.
This bar I call the "spring bar." On this spring bar near to "the stop" I affix a
cross-piece Q Figs. I, and V, about sixteen inches and a half from the ground
lever hereinafter mentioned, and extending upwards towards and terminating near
(about half an inch) from the cylinder. Behind this "cross-piece," and between it
and the "spring-post," and round the "spring bar," I affix a spiral spring R. Fig. I
of strength sufficient, in the absence of resistance, to cause the spring-bar to move
quickly such a distance (about one inch) as will carry the other or further end of
it having the square head Figs. I, II, and V, under the ground lever.
On the road, at right angles with, but below the level of the lines or metals on
which the railway trains run, I place an iron bar of suitable shape and length,
which I call the "ground lever," S Fig. II. One end of this ground lever is fitted
on a suitable bearing under the train line at Y Fig. 11, and the other end is carried
or extended to and upon the "lever-rest" hereinafter mentioned as shewn at S¹
Fig. II. This ground lever is pivoted at or near the middle, S2 Fig. II, so that
as one end is depressed a certain distance (about 2 inches) the opposite end is
raised an equal or greater distance. The end of the ground lever under the rail I
call the "rail end."
The other end of the ground lever (near the cylinder which I call the "signal
end" of the ground lever) is turned up and slotted, V Figs. 1, IV, V and VI, so as
to enclose, or fit over, or round the outer end of the "
stop bar" before mentioned.
A spindle or pivot is inserted at this point through the ground lever and stop bar T,
Figs. I, IV, V and VI, on which the stop bar may work.
Below the signal end of the ground lever is placed a block of wood, or other
material, U, Figs. I, II, IV, V and VI, on which it rests until lifted, and on
which the head of the spring bar, P¹, Figs. I, II and V, rests when the lever at
that point has been raised. This block I call the "lever-rest."
On the rail end of the ground lever I affix two flat bars of iron, one on each side
of the ground lever, which I call "pressure-bars," W and W₁ Figs. II and III,
about 12 feet long-(or even longer if thought desirable) and one inch wide,
working at the ends furthest from the ground lever, on a small knuckle X and X',
Figs. II and III, or in, or between suitable guides; and I place those ends with
the knuckles, or guides, so far down as to be below the reach of the flange of the
engine wheel (so that the flange shall not strike the pressure bars until it has
passed over the knuckles, or guides, a distance of about twelve to eighteen inches)
and rising to a suitable point (about one inch) above the level of the rail.
These bars thus form inclined planes, and their ends over the ground lever are so
constructed, or fitted, as that when they are depressed to their lowest level they
close upon each other at Y. Figs. II and III.
These bars also should not be too thick or heavy, only sufficiently so, as to make
them rigid enough to bear the pressure of the engine wheels, (they are not to bear any
weight from the engine) yet they are to be light enough to be easily raised to their
normal position as shewn in Fig. III by the weight of the signal end of the ground
lever plus the stop bar attached to it at T Figs. I, IV, V, and VI.
The weight of the signal end of the ground lever plus the stop bar at the point
last mentioned should be so adjusted as to overcome the weight of the pressure-bars,
for which purpose the signal end of the ground lever may be made much heavier
than the rail end either in itself or by the addition of a weight being attached to it.
The apparatus hereinbefore described having been fitted and adjusted in the
manner hereinbefore mentioned operates as follows;
As a locomotive approaches, the flange of its front near wheel strikes the first
pressure bar about 12 to 18 inches from, or after it has passed over the first of the
knuckles, or guides, X Figs. II and III, before mentioned, and passing along the
pressure bar, depresses it, and with it the rail end of the ground lever, about two

page_text: ches; and as it travels along the second pressure bar, it continues the depres
the ground lever while the second wheel of the engine is travelling over the first.
ressure bar, and so on with each wheel of the near side of the engine and tender.
nd the next following wheel. This depression of the ground lever S Fig. II,
auses the signal end of such lever at S₁ Figs. I, II, IV, V and VI, to rise about
vo inches which thereupon carries up a like distance that end of the stop bar K
igs. I, II, IV, V and VI, which is connected with the signal end of the ground
ever at the point where the spindle is inserted at T, Figs. I, IV, V, and VI, and
epresses the other end of the stop bar about one inch and a half, and thereby
elieves the cylinder from its stopping, or negative, pressure. (This movement of
he stop bar K is shewn on Figs. I, and IV, by dotted lines.) The cylinder being
hen free to move, is made to revolve by means of the weight, C Fig. I, herein-
efore mentioned, such a distance as will be equal to the descent of the back end of
he signal arm on the signal post; the weight, C, being fitted to the cylinder at.
uch a point as that when it has completed the required descent, it (the weight) is.
stopped by the "stop block" L, Figs. I, IV, V, and VI.
For the purpose of illustration the arc of the circle described by the back end of
the signal arm is assumed to be seven inches, more or less. The arc of the circle.
described by the cylinder must therefore be the same length viz. seven inches, more.
or less. As the cylinder describes an arc of a circle about seven inches in length it
draws the signal chain or rope, D, Fig. 1, (which runs over the top of the cylinder),
the same distance (of seven inches more or less) which will be sufficient to pull
down the back of the signal arm, thereby raising the arm itself to the horizontal,
position which indicates danger to a succeeding train.
The same movement of the ground lever in raising one end of the stop bar, also.
at the same moment releases the spring bar P, Figs. I, II, and V, the head of
which, P, Figs. I, II and V, had been previously pressed against the lever by
means of the spring, R Fig. I at the end of it, or by the weight A. m, Fig. V.
On the signal end of the ground lever S¹ Figs. I, II, and V, being lifted (about.
two inches) the spring, R, Fig. I, or the weight A m, Fig. V, at once thrusts the
spring bar P, Figs. I and V, forward about one inch so that the other end or head.
of it, P¹, slides under the ground lever upon the lever rest, and thereby prevents.
the lever from returning to its level, or horizontal position..
This movement of the spring bar is taking place whilst the engine and tender.
wheels are running over the pressure bars.
The signal is taken off, or placed at safety, by the signalman drawing in the
second chain or rope before mentioned E Fig. 1, (niz. the chain or rope carried
under the cylinder to the signal box). This he may do by a lever, such as is now
commonly used in signal boxes; or a cylinder, or pully, over which the chain or-
0 rope
is run, so that the end may hang down from above the signalman's head, and.
having a small weight to keep it taut.
The operator by pulling in this chain or rope causes the cylinder A. Fig. I to.
revolve back to its original position as herein before described, viz., that position
This revolution at once releases the signal
when the stop is below the centre.
5 chain D Fig. I, (viz. the chain which runs over the top of the cylinder) and
causes it to recede towards the signal post. The tension being thereby taken off
the signal chain, the signal arm is set free and it at once descends to the diagonal
position of safety.
The same back movement of the cylinder causes the adjusting bar F, Figs. I,
50 and V, to engage the cross-piece Q, Figs. I, and V, on the spring bar P, Figs. 1,
II, and V, and push it back (about one inch) against the spring R, Fig. 1, or
to return the weight A m, Fig. V, to its normal position. In doing so it draws the
head of the spring bar P, Figs. I, II and V, from below the end of the ground
lever, S Fig. 11 at S', Figs. 1, 11 and V, which thereupon returns to its horizontal
55 position.
At the moment when the spring bar is pushed back a sufficient distance to allow
the lever to return to its original position, the adjusting bar, F, Figs. I, and V

page_text: passes over the top of the cross-piece Q, Figs. I, and V, and sets it free from
pressure. The spring bar is thereupon free to move again when the next train
passes.
When the spring bar, P, Figs. I, II, and V, has been thrust under the ground
lever in manner before mentioned, at P₁, the cross-piece upon it, Q, Figs. I, and V,
is on one side of the adjusting bar, but it forms no obstruction to the cylinder as it
revolves, when setting the signal to danger, because, as before mentioned, the
adjusting bar, F, Figs. I and V, swings on a spindle placed below the centre of the
cylinder. As the cylinder moves by the weight on its side, the adjusting bar, F
Figs. I and V, is made (by contact with the crosspiece, Q, on the spring bar) to
describe an arc of a circle less than the circle described by the cylinder, and
thus to slide-over-the-top of the crosspiece on the spring-bar without obstruction.
When the operator has drawn in the chain or rope so far as to set the signal
to safety (and he cannot do more because the cylinder has gone back so far as to
carry the
stop" B, Figs. I, IV, V and VI against the stop-block L in the same
figures, and thus prevents it going further) he releases the chain E Fig. I, but
does not make it fast, for when the cylinder is set free by the passing engine, and
is drawing up the signal arm to danger, the cylinder is, at the same time, drawing
back the chain or rope E Fig. 1, from the signal box.
65
The weight, C Fig. I, carried on the cylinder, is therefore made sufficiently
heavy to be able to overcome the resistance of the signal arm and the two chains
combined.
It is not necessary that the apparatus should be placed close to the signal post:
it may be placed at any spot between the signal post and signal box at which the
resistance on each side of it may be somewhat equalized.
The arrangement for sustaining the ground lever when raised at the signal end,
and the spring bar itself may respectively be varied or modified, and the spring
may be dispensed with, other methods being adopted as alternative methods of
carrying out their several functions.
One modification is illustrated by. Fig. IV; and for the sake of brevity in
describing this modification I omit the words "Fig. IV" after each reference
letter. This modification is as follows, viz., to make the spring-bar of an irregular
shape, P, placed in a vertical position, working on a spindle, Z, at the bottom,
and having a shoulder, Za, to fit over, or engage, the end of the "stop-bar," K,
under the cylinder, A, and an inclined surface, Z b, from the top downwards,
against which the end of the stop-bar K travels as it descends, thereby pushing
the spring bar, P, back about one inch against the spring, R. On the stop-bar
Fassing the angle made by the inclined surface, Zb, and the shoulder, Za, (which
form two sides of a triangle) the spring, R, thrusts the spring-bar, P, back to its
vertical position, whereby the shoulder, Za, at once engages the upper side of the
stop-bar and retains it in position until the signal is taken off.
When the operator desires to take the signal "off," or place it to "safety," he
draws back the cylinder in the manner before described when the adjusting bar F
engages the top of the upright spring-bar, P, and pushes it back, as shewn by
dotted lines, until it (the adjusting bar) passes over the top of the spring-bar,
on which such spring bar reverts to its vertical position by means of the spring
behind it.
Another method or modification is shewn in Fig. VI. In describing this
modification I also omit the words "Fig. VI" for the sake of brevity. In this
modification I first extend the back of the lever-rest, U, upwards as shewn at U',
and carry across from the top of it to the slot-post, J, a bar, U2, and bolt such cross
bar on to the slot post, and the top of the lever rest, and in this bar, U2, I cut a slot.
I then also extend the signal end of the ground lever upwards as shewn at S3 and
carry it through the slot in the bar, U2: Upon this extension of the ground lever
I affix a bar of iron, A a, (which I call the "oscillating bar") with a slot in it
working on a pin at Ab, in the ground lever, and pivoted on a spindle at A c on to
the slot post J, (or on a bracket on the slot post), with a cross bar Ad, on the same

page_text: t or spindle, A c, carrying at the lower end a proje
e as will place that projection, or foot, under the ground lever as it is raised at.
signal end, and there suspend the lever, and prevent it from returning to its
izontal position.
The motions of the stop bar, K, the oscillating bar Aa, and cross bar, A d, in
3 modification are shewn by dotted lines in Fig. VI.
a,
and
The spring bar, P, in this case is irregular in shape, having, like the spring bar
the last instance (P Fig. IV) an inclined surface and a shoulder, but it is pivoted
the slot post at such a point as will place the inclined surface against the
illating bar, A a, which works on the ground lever at, A b. As the signal end of
e ground lever at S' rises it will raise one arm of the oscillating bar, A
press the other arm against the inclined surface, Zb, of the spring bar, P, and
ereby thrust it back against the spring, R, until such oscillating bar passes the
gle Za and Zb of the spring bar, P, when the spring bar reverts to its normal
osition; but in so doing it engages the end of the oscillating bar, A. a, and so
etains the ground lever by suspension. The spring bar in this case is drawn away
rom the oscillating bar by means of rods, A. and Aj, and oscillating or bell crank
evers, Ak and Al, in shape somewhat like the letter V, fitted to the slot post and
perated upon by the adjusting bar F, which in this modification is placed at the
The effect of the weight, C,
ide of the cylinder as shewn in the Fig. VI, and fitted with a small weight so as to
keep it constantly in a horizontal position when at rest.
on the cylinder, in this form of my invention, is to carry the adjusting bar, F, above
When the cylinder is drawn back by the operator the adjusting
the bell crank A k.
bar, by reason of its horizontal position and so retained by the stop G, comes into
contact with, or engages, the bell crank A k on its upper side, and forces that arm
of the bell crank downwards: this causes the other arm to. rise, and in so doing to
The rod Ah, in rising draws upwards the lower
draw up the vertical rod Ah:
arm of the bell crank A l, and thereby moves the vertical arm of the same bell
crank to the right. This vertical arm as it moves to the right draws the spring
bar, P, back, by means of a red Aj. The spring. bar P, being thus drawn back,
sets free the oscillating bar, A a, so that it can at once revert to its normal
position.
Another modification may be effected by dispensing with the spring and using a
weight instead thereof, which will cause the spring bar to slide forward when set
free. This is shewn at A m, Fig. V. In this figure the reference letters relate to
the same parts of the apparatus as are shewn in Fig. I.
Fig. VII shews the following details. An, is a front view of the top of the
cross-piece Q in Figs. I and V. This top is to be turned as shewn at An, and
rounded so that the adjusting bar F Figs. I and V, may pass over without slipping
0 round it in a lateral direction.
K, in this fig. shews the end of the stop bar enlarged for the purpose of not only
holding in check, "the stop," B, but also the irregularly shaped spring bar P as
shewn in Fig. IV.
A o, in this figure shews the top of the last mentioned spring bar as it stands
45 between the stop bar K, and the spring R.
L, in this figure shews the top of the stop-block as made for Fig. IV. The
whole of these contrivances, K, B, L, and A'o, and the spring, R, are here shewn
in position as related to each other as constructed according to Fig. IV.
Ap, is a section of the pressure-bars, shewing raised edges between which th
50 flange of the engine wheel may run.
Aq, in this figure, shews the rail, the pressure bar, and the wheel in position i
relation to each other.
Small mechanical contrivances for keeping the several parts of the apparatus i
position are not shewn in my drawings, as such contrivances are well understood b
55 engineers and fitters; as for example, in Fig. IV I indicate at Ar, by dotted lin
a contrivance for keeping the stop bar aud spring bar in position so that they ma
work truly without any lateral vibration.
"

page_text: In like manner, in fitting the. several parts of the apparatus, care should be
exercised to protect them by guides, pins, or other contrivances from obstructing
each other, so that where they have to pass each other they may do so freely; or,
in other cases to guard against slipping or lateral movements. As for example, the
stop bar, K Fig. I, may be protected from moving out of its true line by two small
upright bars being fitted on to the bracket close to the knuckle shewn in this figure
-one bar being placed on each side of the stop bar K. And in like manner the
pressure bars should be protected by suitable guides from lateral movement when
wheels are passing over them. And the head of the spring bar P¹ may be fitted
with steel rollers whereby it may the more easily be withdrawn from below the
ground lever. These rollers may be fitted at the places indicated by large black
dots on P Fig. I.
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
D
1. The improved apparatus for placing or setting railway signals at danger by
pressure from the wheel of a passing engine, and the modifications thereof as and
for the purposes hereinbefore described and illustrated by the drawings hereunto
annexed.
Dated this First day of November One thousand eight hundred and ninety-
three.
Witness:
H. DICKENS DALLIMORE,
316, Camberwell New Road, S.E.
H. G. DALLIMORE.