Improvements in Mechanism for Interlocking Railway Signals and Points.
Year: 1892

page_text: Date of Application, 26th May, 1892
Complete Specification Left, 6th Jan., 1893-Accepted, 11th Feb., 1893
PROVISIONAL SPECIFICATION.
Improvements in Mechanism for Interlocking Railway Signals and
Points.
We, ALEXANDER Ross, of London Road Station, Manchester, in the County
of Lancaster, Engineer to the Manchester Sheffield and Lincolnshire Railway
Company, and THOMAS WHARMBY, of 18 Audenshaw Road, Guide Bridge, in the
said County, Signal Inspector to the said Company, do hereby declare the nature
of this invention to be as follows:-
Our invention relates to improvements in mechanism for interlocking railway
signals and points and the chief object of our improvements is to protect a train
which has been shunted from one main line to another, or which is standing at a
starting signal.
For convenience of description let it be supposed that a slow or goods train on
the up line has passed the home signal; but has been pulled up on account of the
starting signal being against it. In order to make way for an express or following
train on the up line it is necessary to shunt the goods train on to the down line.
The signalman therefore pulls over the lever which actuates the cross over points,
thereby liberating the disc or other signal lever which he also pulls over, and the
goods train then passes on to the down line. Now prior to our invention it has
been possible for the signalman to take off the home and distant signals for the
down line if forgetful of the fact that a train is already standing upon that line.
We, however, so combine the interlocking arrangements that it is impossible for
the signalman to take off the home or distant signals on the down line until the
cross over points have been again pulled over, the disc or other signal given to
allow the goods or other train to return to the up line and the signal and cross
over point levers have been put back after the train-then the home and distant
signals can be taken off to allow a train to pass.
The signals may be interlocked as above described by any suitable mechanical
device; but we prefer to employ a special device of our own invention which
consists in an incline formed or fixed on the blade attached to the disc or starting
signal lever or other required lever, and which incline causes the blade to rise and
pass over the tappet without moving the same to unlock the lever which that tappet
controls until the blade is drawn back by the action of putting back the lever to
which it is connected.
In order to protect a train which is standing waiting at the starting signal, we
propose to employ our special interlocking device so as to prevent the signalman
from taking off either the home or distant signal behind the waiting train, until he
has first taken off the starting signal and again put back the same to danger
whereby he unlocks both the home and distant signals.
Dated this 25th day of Mor 1809
H. B. BARLOW,
Agent for Applicants.
COMPLETE SPECIFICATION.
Improvements in Mechanism for Interlocking Railway Signals and
Points.
We, ALEXANDER Ross, of London Road Station, Manchester, in the County
of Lancaster, Engineer to the Manchester Sheffield and Lincolnshire Railway
Company, and THOMAS WHARMBY, of 18 Audenshaw Road, Guide Bridge, in the
said County, Signal Inspector to the said Company, do hereby declare the nature
Price 8d.l

page_text: 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 :-
Our invention relates to improvements in mechanism for interlocking railway
signals and points and the chief object of our improvements is to protect a train
which has been shunted from one main line to another, or which is standing at a
starting signal.
For convenience of description let it be supposed that a slow or goods train on
the up line has passed the home signal; but has been pulled up on account of the
starting signal being against it. In order to make way for an express or following
train on the up line it is necessary to shunt the goods train on to the down line.
The signalman therefore pulls over the lever which actuates the cross over points,
thereby liberating the disc or other signal lever which he also pulls over, and the
goods train then passes on to the down line. Now prior to our invention it has
been possible for the signalman to take off the home and distant signals for the
down line if forgetful of the fact that a train is already standing upon that line.
We, however, so combine the interlocking arrangements that it is impossible for the
signalman to take off the home or distant signals on the down line until the cross
over points have been again pulled over, the disc or other signal given to allow
the goods or other train to return to the up line and the signal and cross over
point levers have been put back after the train-then the home and distant signals
can be taken off to allow a train to pass.
The signals may be interlocked as above described by any suitable mechanical
device, but we prefer to employ a special device of our own invention which
consists in an incline formed or fixed on the blade attached to the disc or starting
signal lever or other required lever, and which incline causes the blade to rise and
pass over the tappet without moving the same to unlock the lever which that tappet
controls until the blade is drawn back by the action of putting back the lever to
which it is connected.
In order to protect a train which is standing waiting at the starting signal, we
propose to employ our special interlocking device so as to prevent the signalman
from taking off either the home or distant signal behind the waiting train, until he
has first taken off the starting signal and again put back the same to danger
whereby he unlocks both the home and distant signals.
And in order that our invention may be fully understood and readily carried into
effect we will describe the accompanying two sheets of drawings reference being
had to the figures and letters marked thereon.
Figure 1 is a diagram of a cross over road from one main line to another to the
signals and points of which our improvements are applied.
Figure 2 is a front sectional elevation Fig. 3 a plan and Fig. 4 an end sectional
elevation of the levers and interlocking gear illustrating the mode of and means for
interlocking the signals and points according to our invention.
In Figure 1 the signals and cross over points represented are numbered as
follows:-
.1 up line home signal, 2 up line starting signal, 3 disc signal, 44 cross over road
points, 5 disc signal, 6 down line starting signal, 7 down line home signal.
The distant signals for both down and up lines are shown; but not numbered as
the mode of working and locking them forms no part of our present invention.
In Figures 2 and 3 the tappet blades of the levers and the levers themselves
bear the same numbers as the signals and points which they respectively control;
thus No. 1 lever controls the up home signal, No. 2 lever the up starting signal,
No. 3 lever the disc signal 3, No. 4 lever the cross over points, No. 5 lever disc
signal 5, No. 6 lever the down starting signal and No. 7 lever the down home
signal.
The back row of tappet blocks or locks are lettered a, b, c, d, e, f, and the tappet
blocks a, b, e and f are bevelled or inclined on their top surface where marked .x
and similarly the tappet blades 1, 2, 6 and 7 are marked where their under
surfaces are correspondingly bevelled or inclined.

page_text: The tappet blocks a and b are connected together by a slide bar 9 a projection on
which enters a slot in the tappet block c and another projection a slot in the tappet
block d; similarly the tappet blocks e and fare connected together by a slide bar h
a projection on which enters a slot in the tappet block d and another projection a
slot in the tappet block c.
The front row of tappet blocks are not material to our invention; but are shown
for the sake of clearness in description, and also to illustrate fully the mode of
applying our improvements to the ordinary system of locking. These blocks are
lettered j, k, l, m, respectively and the two outer blocks j and m are connected to
the two inner by slice bars with projecting ends and m¹ which lie in slots in the
blocks and 1.
In operation if it be necessary to shunt a train from one main line to the other
say from the up to the down line the levers would be operated as follows:-
No. 4 lever is pulled over thereby opening the cross over road and as usual
locking both the levers 1 and 7 which control respectively the up and down home
signals.
No. 5 lever is pulled over thereby taking off the disc signal 5 locking lever 3
controlling disc signal 3 and also putting a special lock into lever 7.
The train can now pass from the up to the down line after which the levers 5
and 4 can be put back; if however the signalman should forget the shunted train
standing at the starting signal 6 on the down line and endeavour to pull over
lever 7 so as to take off the down line home signal, he will find that he is unable to
move lever 7 on account of the special lock put in by the movement of disc signal
lever 5 until he has first pulled over and put back the starting signal lever 6 or
else operated levers 4 and 3 to allow the train to return to the up line. The act of
pulling over the lever 6 will not take the lock out of the lever 7 because the
incline y on the tappet blade 6 mounts the incline a on the tappet block e and so.
passes over the latter without moving it. When however the lever 6 is put back
again the oblique edge y¹ thereon acts on the oblique surface and pushes back
the block e and with it the block finto the positions shown in the drawings, thereby
taking the lock out of the lever 7 and so allowing the signalman to pull over said
lever and take off the down line home signal.
In like manner if a train is to be shunted from the down to the up line the levers
would be operated as follows:-
No. 4 lever is pulled over to open the cross over road and lock both the levers 1
and 7 in the usual way.
No. 3 lever is pulled over to take off the disc signal 3 lock lever 5 controlling
the disc signal 5 and also put a special lock into lever 1.
The train can now pass from the down to the up line, the levers 3 and 4 can then
be put back; but on account of its special lock the lever 1 cannot be pulled over
to take off the up line bome signal until the starting signal lever 2 has been first
pulled over and put back or levers 4 and 5 have been operated to allow the train
to return to the down line.
This arrangement of interlocking has also the advantage of protecting a train
which has passed the distant and home signals; but has been pulled up at the
starting signal.
For example if lever 1 be pulled over and the home signal on the up line taken
off and a train pulled up at the starting signal 2 the signalman can put back lever 1
to protect the waiting train; but he cannot again pull the lever I over to take off
the up line home signal until lever 2 has first been pulled over to take off the
starting signal 2 and then put back again. This interlocking is effected by the
oblique edge on the blade 1 which when the lever 1 is pulled over pushes
the tappet block b sideways and thereby pulls the tappet block a into the back
notch of the lever 1; when the lever 1 is put back the incline y thereon mounts the
incline on the block a and so allows the tappet blade 1 to ride over the block a
without moving it and the front notch to drop over and be locked by said block.
To take the lock out of the lever 1 it is necessary to pull over lever 2 the tappet

page_text: blade of which by means of the incline y rides over the inclinex on the block b and
allows the back notch on said blade to drop over the block without moving it or
the block a. When however the lever 2 is put back the oblique edge y³ on the
tappet blade 2 pushes back the tappet block band with it the block a thereby
taking the lock out of the lever 1.
Again if lever 7 be pulled over and put back the oblique edge y' as the lever is
pulled over moves the block e and with it the block and the lever 7 cannot again
be pulled over to take off the down line home signal until lever 6 has been pulled
over and put back to take the lock out of lever 7.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. The herein described improvement in mechanism for interlocking railway
signals and points which improvement consists in so arranging and combining the
locking either by the means specified or by equivalent means that after the home
signal lever (on either the up or down line) has been pulled over and put back
again it cannot again be pulled over until the starting signal lever has been pulled
over and again put back.
2. The herein described improvement in mechanism for interlocking railway
signals and points which improvement consists in so arranging and combining the
locking either by the means specified or equivalent means that after the cross over
point and disc signal levers have been pulled over to allow a train to shunt from
one main line to the other the home signal lever for the line to which the train is
shunted will remain locked until released by pulling over and putting back the
relative starting signal lever or the cross over points and the reverse disc signal
levers to allow the train to return over the points.
3. The combination with an incline y on the underside of a lever tappet blade, of
an incline x on a corresponding tappet block or lock for the purpose of allowing
said tappet blade to mount and ride over the tappet block without moving it
substantially as herein described and as illustrated by the accompanying drawings.
4. The combination and general arrangement of parts constituting our special
mechanical device for interlocking railway signals and points substantially in the
manner and for the purposes herein described with reference to the accompanying
drawings.
Dated this 5th day of January 1802
H. B. BARLOW & GILLETT,
17, St. Ann's Square, Manchester, Agents for Applicants.