Improvements in Railway Signalling Apparatus.
Year: 1893

page_text: Date of Application, 12th May, 1893-Accepted, 17th June, 1893
Improvements in Railway Signalling Apparatus.
I, WILLIAM SAUNDERS, of 34 Park Grove Battersea Park Road London
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 :-
This invention relates to improvements in railway signalling apparatus and
has for its object to provide an automatic mechanical block signalling systein
for the safe working of railways in bright or foggy weather and which shall
not be affected by any sudden changes in the temperature.
For this purpose "Y provide the engine of a train running on this system with
a gong or alarm on each side thereof each operated by means of a pivoted lever
coming into contact with various cranks or treadles fitted to the permanent way.
The first of these cranks or treadles is placed about 500 yards in front of the
signal post towards which the train is approaching on the left hand side of the
line, whilst a second one is placed about 100 yards in front of the said signal
post, also on the left hand side, and a third crank or treadle is placed about
20 yards from the signal post, but on the right hand side of the line. These
cranks or treadles are operated, so as to project above the line or to lie down
level therewith by means of a rotating locking drum fitted to the signal post
which drum also actuates the signal arm or semaphore. The said drum is con-
nected by means of arms or levers to another drum carried in bearings in near
proximity to the signal post, and this drum and consequently the locking drum
is operated by levers and a fourth crank or treadle fitted to the left hand side
of the line.
The signal operating wire is coiled once around a pulley actuating the said
drum, its free end being connected to a weight hanging perpendicularly there-
from. The other end of the said wire is likewise coiled once around another
and larger pulley supported in bearings near the signal box, this end of the
wire being also connected to a depending weight, or it may be fixed to the
periphery of the said pulley. This latter pulley is formed with a part of smaller
diameter to which is attached a chain or rod connected to the signal lever whereby
the signal wire is operated. This arrangement of pullies constitutes a
pensating device to provide for the expansion and contraction of the signal wire
without affecting the working of the signals and for which device I have obtained
former Letters Patent No. 8586 dated 28th April 1893.
com-
A fifth crank or treadle also fitted to the left hand side of the line actuates a
locking plate to lock the signal in its danger position. I also provide another set
of pullies around which a wire is coiled and provided with weights, in a similar
manner to the first set, for the purpose of actuating a plate for unlocking the
signal from its danger position, these pullies being operated by a sixth crank or
treadle likewise fitted to the left hand side of the line, but some little distance
beyond the next signal post so that there shall be an absolute block between the
two signal posts until the train has passed clear of this last crank or treadle and
so permitting the signal to be lowered. The same cranks or treadles and com-
pensating devices are placed in front of and beyond this second signal-post, as
those described with reference to the first, and also to each signal post along the
line, so as to form a block between the said signals.
And in order to explain more particularly my said invention and the manner

page_text: of carrying it into practical effect I will describe the same with reference to the
accompanying drawings in which
Fig. 1 is a diagrammatic view in elevation of my improved signalling apparatus
and Fig. 2 is a plan of the same.
Fig. 3 is a view showing the signal locking and unlocking device and Fig. 4 is a
view at right angles to Fig. 3 partly in section.
Fig. 5 is a view shewing the locking plate operating mechanism and Fig. 6 is a
plan thereof.
A. B. represent two signal posts, and C C' are the two rails of a single track of
the permanent way. E is the engine or locomotive to each side of which is fitted
a gong or alarm G-these gongs are operated by levers L pivoted to the frame of
the engine. 1 and 2 represent cranks or treadles pivoted in bearings on the
left hand rail C at points about 500 and 100 yards from the signal post A
respectively.
The crank or treadle 3 is pivoted to the right hand rail Cat about 20 yards
from the signal post.
a represents a locking drum pivoted in bearings to the signal
post A. as shewn more clearly in Fig. 3. To the said drum a is attached an arm a¹
connected by rods a² to the said cranks or treadles so as to raise them above or
lower them below the level of the rails C C¹ the cranks 1 and 2 being raised
together whilst 3 is lowered or vice versa. The drum a also actuates the signal arm
or semaphore a through the rod a*. The said drum is connected by arms or
levers to another drum c carried in bearings c¹ as shewn more clearly in Fig. 4,
d is a pulley supported in bearings d' and provided with an arm which comes in
contact with an arm or projection e² fixed to the drum c for operating the latter
and consequently the signal arm. Around the pulley d is coiled once the end of
the signal wire e the said end being attached to a depending weight e¹. The other
end of the said wire is coiled once around a pulley of larger diameter than the
pulley d and placed near the signal box S this end of the wire being connected to
a depending weight for the wire may be connected to the periphery of the
pulley instead of to the weight f₁. The pulley f is formed with a part of
smaller diameter around which a chain g is partly coiled, or to which a rod is
attached, the said rod or chain being connected to the signal lever / whereby the
signal is operated from the signal box. The weights e and f' always keep the
wire e taut however much it may expand or contract and also counter balance each
other thereby lessening the power necessary to operate the said wire, and the
diameters of the pulleys d and fare so proportioned that about one quarter turn
of the pulley will cause a complete revolution of the pulley d thus allowing the
wire in contracting to pull the latter pulley round once before its arm d² can come
into contact with the projection c³ to lower the signal arm. The diameters of the
compensating pullies d and are of course proportioned to the length of wire
between them to allow of such contraction.
The end flanges of the locking drum a are formed with notches a to receive the
sliding locking bolt i which bolt is operated by pivoted plates jk. A crank or
treadle 4 fitted to the left hand rail Cactuates by means of levers 1, the pulley c
and the locking drum a to put the signal to danger upon the train passing over the
said crank or treadle 4. Another crank or treadle 5 also fitted to the left hand
rail C is actuated by the train passing over the pivoted plate m and operates a
rod n whose end passes underneath the horizontal limb k¹ of the plate k so as to
move the plate and consequently the locking bolt i into their locked positions.
The said bolt and consequently the signal arm is unlocked by means of a com-
pensating device similar to the one already described and consisting of a pulley o
and a pulley p around which is coiled the operating wire whose ends are attached
to weights qq. To the axis of the pulley o is loosely pivoted a bent lever r whose
free end passes underneath the horizontal limb of the plate j. The lever r is
operated by means of a projection o' on the pulley o when the said pulley has been
pulled round a complete revolution by the wire q the projection raising the free
end of the lever r thus forcing the plate j towards the signal post and pushing

page_text: back the locking bolt i until its recessed parts are opposite the flanged ends of
the drum a thus unlocking the latter and permitting its being turned to operate the
signal arm. The plate is provided with a bolt or piu which enters a recess in
the drum a thus preventing the latter being operated until the plate ; is free to
return to its normal position as shewn in Figure 3.
The wire q is operated by a crank or treadle 6 and the levers s connected to the
pulley p so that the signal arm cannot be lowered until the whole of the train has
passed the said crank or treadle 6 thereby providing a complete "block" during
the time the train is passing between the signal post A and the crank or treadle 6.
Should the wire g break I provide a second pivoted lever u one end of which
also passes underneath the limb j' of the plate j, the wire passing through a per-
foration in the other end of the lever and being provided with a plate or button v
resting upon the said lever, so that in the event of the wire breaking when the
signal is unlocked the weight o' will fall and raise the lever u so as to force back
the platej into its locked position thus locking the signal.
66
The operation of my improved signalling apparatus is as follows. Supposing a
train to be travelling in the direction of the arrow Fig. 2, and the signal to be at
danger" the lower end of the lever L on the left hand side of the engine will
come into contact with the crank or treadle 1 and thus cause the gong G on that
side of the engine to be operated and should the signal be still at "danger" when
the engine reaches crank or treadle 2 the gong will be sounded a second time, but
should the signal arm be in the meantime lowered the cranks or treadles 1 and 2
will be lowered and the crank or treadle 3 will be raised thus operating the gong
on the right hand side of the engine and signifying that the latter may proceed.
The engine then passes over the crank or treadle 4 thus raising the signal arm to
its "danger" position, it then passes over crank or treadle 5 which actuates the
plate k so as to lock the signal in this position. The train then proceeds until it
reaches a similar arrangement of cranks or treadles in connection with the next
signal post B which is operated upon in a similar manner to that described with
reference to signal A. After the train is clear of signal post B. it passes over the
crank or treadle 6, which is operated by a long pivoted plate t, thus acting upon
the plate to unlock the signal arm A and permitting the latter being lowered by
the signal box lever when the whole of the train has passed over the said plate t.
By this arrangement it will be seen that one train cannot follow another until the
distance between two succeeding signals is clear, thus providing an absolute and
automatic block system of signalling.
Having now particularly described and ascertained the nature of my said inveu-
tion and in what manner the same is to be performed 1 declare that what I
claim is.
1. The improved arrangement of railway signalling apparatus consisting in the
combination of the cranks or treadles the gongs and alarms the rods and levers,
and locking and unlocking devices whereby the signals are operated and locked and
unlocked by the passage of the train, substantially as described and shewn and for
the purpose specified.
2. The combination of the improved signalling apparatus as above claimed
with the improved wire compensating devices substantially as described and for the
purposes specified.
3. The improved railway signalling apparatus substantially as described and
shewn in the accompanying drawings, and for the purposes specified.
F. G. CASSELL,
Of Cassell & Co.,
22, Glasshouse Street, Regent Street, London, Agent for the Applicant.