Improvements in Signal and Point Apparatus for Railways.
Year: 1897

page_text: Date of Application, 12th Jan., 1897-Accepted, 27th Mar.,
1897
COMPLETE SPECIFICATION.
Improvements in Signal and Point Apparatus for Railways.
A communication from abroad by EDWARD WALLER STONEY, of the Madras
Railway, Madras, India, Civil Engineer.
I, GEORGE BELOE ELLIS of the Firm of J. C. Mewburn and Ellis of
55 and 56 Chancery Lane, in the County of London, Chartered Patent Agents,
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 signal and point apparatus for railways, and it has for.
its objects (1) To enable each pair of signal arms placed either on a single or
bracket post to be worked by means of one lever and a single line of wire or
rodding; (2) To ensure the main or loop line home signal being. "off" before the.
corresponding distant signal can be lowered, which when lowered then locks the
off home signal and prevents the latter from being again placed at "danger" until
the distant signal is first placed at "danger" also; (3) To interlock by simple
means the points and signals of a station in such a manner as to exclude the
possibility of conflicting signals being given, and also so that signals cannot be
lowered until the corresponding points are first properly set and locked; (4). To
render it impossible to lower the necessary signals for a train to come in, ruu
through, or start from a station, until all the points over which the said train has
to pass, have been properly set and locked for its passage; and (5) To prevent..
the points being unlocked or moved while a train is passing over them, or until
after their corresponding signals have been placed to and locked at "danger."
These objects are effected by improved combinations of means in the manner
which is hereinafter described more especially with reference to the working of
the station signals and points of a station on a single line railway comprising
a main line section, a shunting loop, and a "lay-bye" or siding branching off from
the loop.
In such a case the station signals are worked by means of six levers mounted
in a suitable frame conveniently situated on the station platform, near the station
master's office, the arrangement being such that five up signals are worked by
three levers viz. :-one lever for the up-distant signal; one lever for both the up
up main
main home signal and the up loop home signal; and one lever for both the
starting signal and the up loop starting signal.
The five down signals are worked also by means of three levers, in an analogous
manner. Each pair of main line signals is worked by a single wire, and each pair.
of starting signals is also worked by one wire.
The points are worked locally by pointsmen at them, and the signals are worked
by the station master from the station by means of the aforesaid six levers and
their wires the signals and the points being controlled and interlocked by means of
locks arranged in locking boxes, one for each switch or set of points as hereinafter
described, each of these locks being adapted to be locked and unlocked by the
insertion of the proper keys. The locking boxes are firmly fixed midway between.
the rails so that they cannot be interfered with or have a key inserted therein or
removed therefrom while a train is passing over the points and consequently over
the said locking boxes.

page_text: For the purpose of locking and interlocking the up and down home signals the
lower ends of the rods of these signals are arranged to work in suitable guides
and they are fitted with pins which work in slotted holes in the respective ends of
a floating lever. To the centre of this lever which thus connects the lower ends of
the aforesaid signal rods together, there is pivoted a rod to the lower end of which
is attached the wire leading to the home signal lever.
Locks are suitably arranged by means of which the signals are normally
locked at "danger"; corresponding locks being fitted to the lower slide in the
locking boxes for the up and down main points respectively as hereinafter
described.
A locking bar forming part of the wire leading from distant signal to the distant
signal lever on the station platform, is arranged to intersect horizontally at right
angles the aforesaid home signal lowermost bar to which is connected the wire
leading to the home signal lever on the station platform. The locking bar has a
slot through which the said home signal bar can slide, and in the latter bar there
is formed a slot through which the locking bar can pass when either the main or
the loop home signal has been unlocked and lowered. This enables the distant
signal to be lowered and when lowered, to back-lock the home signals and prevent
its corresponding home signals from being again placed at
the distant signal has also been put to "danger."
“
danger" until after
The setting of the home signal is thus made to precede the corresponding setting
of the distant signal.
The pin in the lower end of the loop home signal bar forms a fulcrum for the
floating lever when the main home signal is unlocked and the loop home signal is
locked, so that the main home signal can be pulled off by means of its bar and the
common wire leading to the home signal lever on the station platform. Similarly the
pin in the lower end of the main home signal forms a fulcrum for the floating lever
when the main home signal is locked and the loop home signal is free.
By this arrangement one wire is made to work the two signals in a simple and
certain manner unaffected by expansion or contraction, and the lowering of the
one signal prevents the key from being removed from the lock of the corresponding
signal bar, and when the other signal is lowered, the key of that signal cannot be
removed from its lock.
The up loop and up main starting signals, and the down main and down loop
starting signals are worked in pairs in a similar manner by a single wire for
each pair, and are locked by their respective locks. The keys for the up points
and down points fit the locks of the down starting and up starting signals
respectively.
The locking box for locking the points that give access to and from the
"lay-bye" or siding branch from the loop, consists of a substantially rectangular
cast iron box having a slide passing through it on the lower side of which are
fixed two locks and a bolt for locking the point stretcher bars which move at
right angles to the slide. The "lay-bye" or siding points are normally locked for
the loop line and cannot be unlocked or moved for the "lay-bye" or siding unless
both keys are taken from the two main line locks and are inserted in the siding
locks which can then both be unlocked and the slide drawn to the shunting
position, thereby leaving the bolt clear of the stretcher bar, so that the points can
be set for either side. While the keys remain in the lay-bye or siding locks, neither
the loop home signal nor loop starting signal can be given.
The main line locking boxes are two in number and serve to lock the points that
give access to and from the main line at the up and down junctions of the loop
respectively. Each locking box consists of a substantially rectangular cast iron
box through which pass the switch stretcher bars. At right angles to these is
a lower locking slide; above the latter and moving parallel to the stretcher bars
is a lay-bye or siding locking slide.. The main line slide has two locks, and a
rib on its upper side, to prevent straining the loop key when the "lay-bye."
key is removed, and bolts on its lower side for locking the stretcher bars, and

page_text: points for the main or loop line. The "lay-bye" or siding slide has a lock, a bolt,
and two pairs of suitably formed key hole slots, which allow the loop signal keys
to be got out only when the "lay-bye" or siding points are locked for the loop
line, and the keys from the two locks of the lower locking slide are in the upper or
"lay-bye or siding slide.
"
The key hole slots are however so formed as to allow the main line signal
keys to be taken out even if the lay-bye" or siding lock keys are removed from
the lay-bye or siding slide so as to enable trains to be run over the main line if
necessary while shunting from the "lay-bye" or siding to the loop line is being
done. The points are locked to either side by pulling or pushing the main line
slide which causes the bolts to engage in the slot in the stretcher bars and thus
lock the switches without strain on the locks.
If desired the distant signals may be worked locally by levers at the main points,
since they cannot be lowered by the pointsman until the corresponding home
signals have first been lowered by the station master.
"I shall now proceed with reference to the accompanying illustrative drawings to
describe the application of this invention to the working of the station signals and
points of a station on a single line railway, comprising a main line section, a..
shunting loop and a "lay-bye" or siding branching off from the loop.
In these drawings :-
Figure is a diagrammatic view showing a general arrangement of such a
station with the adjacent portions of the line, the various signals, points, and locks
for the same.
Figure 2 is a front elevation of the arrangement for inter-connecting the home
signals of one side, and interlocking the same with the distant signals.
Figure 3 is a plan of the "lay-bye" or siding points locking box.
Figures 4 and 5 are sections on the line 4-4 and 5-5 respectively of
Figure 3.
Figure 6 is a plan of the main and loop line up and down points locking box.
Figure 7 is a plan of the same with the upper or lay-bye or siling slide
removed.
Figure 8 is a section on the line 8-8 of Figure 7 and
Figure 9 is a side elevation of Figure 6.
In all these figures the same reference letters and numerals are employed to
represent the same parts.
"
A represents the station platform, B the main line, C the shunt loop, and D the
"lay-bye or siding. In this example there are (five up and five down) ten
signals viz. the up distant signal UDS; the up main home signal U MHS
the up loop home signal U L HS; the up main starting signal UMSS; the
up loop starting signal U L S S; the down distant signal D D S; the down
main home signal D M HS; the down loop home signal D L HS; the down
main starting signal D M S S; and the down loop starting signal D L S S.
Correspondingly there are the following eight signal locks-viz. -the up main
home signal lock UM HSL; the up loop home signal lock ULHSL; the
down_main_home signal lock D M HS L; the down loop home signal
lock DLHSL the main up starting signal lock UMSSL; the up loop
starting signal lock ULSSL; the down main starting signal lock D M S S L,
and the down loop starting signal lock D L S S L.
There are also the following point locks viz. the up point lock UP L;
the down point lock D P L, and the "lay-bye" or siding point lock L B L.
Six levers a, b, c, d, e, f, mounted in a suitable frame on the platform near the
station master's office and arranged to be worked by the station master are
employed to work the station signals as follows: -the up distant signal UDS
is worked by the lever a; the up. main home signal U MH S and the up loop
home signal UL H S are worked together by the one lever c by means of a single
wire and the up main starting signal UMSS and the aploop starting signal ULSS
are worked together by the one lever e by means of a single wire. The five down

page_text: signals viz. the down distant signal D D S, the down main home signal D MH S
together with the down loop home signal D L H S, and the down main starting
signal D M S S together with the down loop starting signal D L S S, are similarly
worked by the levers f, d, b, respectively. The up points and the down points
are worked locally by pointsmen. These points and the above mentioned signals
are controlled and interlocked by means of six keys as hereinafter described.
Three locking boxes U PL, D P L, and L B L, shown in detail in Figures 3 to 9,
are employed to respectively lock the up points, down points, and lay-bye" or
siding points, securely to either side by means of two stretcher bars passing
through each box, one bar being connected to each switch tongue. These
boxes U PL, D PL and LB L are fixed horizontally mid-way between the
rails of their respective points so that the boxes cannot he interfered with whilst
a train is passing over the points.
6:
The
Referring to Figure 2 the lower ends of the rods 1 and 2 of the home
signals U MHS and UL HS pass through suitable guides and are fitted with
pins 3, 4 which work in slotted holes in the respective ends of a floating lever 5.
To the centre of this lever there is connected a rod 6 to the end of which is fixed
a wire 7 leading to the home signal lever c on the station platform.
locks UM HSL and UL HSL are placed as shown the signals UM HS
and UL H S being normally locked at danger. Corresponding locks are fitted
to the lower slide in the locking box U PL for the up points. The locking
bar 8 forming part of the wire 9 leading from the up distant signal UDS to
the corresponding lever a on the station platform is formed with a slot 8* through
which the bar 6 can slide. In the bar 6 there is formed a slot 6 through
which the bar 8 can pass when either the up main home signal U MHS or the
up loop home signal U L H S has been unlocked and lowered. This enables the
distant signal to be lowered which in its turn back locks the up home signal and
prevents the latter from being placed to "danger" until after the up distant
signal has been put to "danger.' The home signal is thus made to precede the
distant signal.
"
The pin 3 forms a fulcrum for the floating lever 5 when the main home
signal U MHS is unlocked and the loop home signal UL H S is locked, so
that the main home signal can be “pulled off" by means of the bar 6 and its
wire 7. Similarly the pin 4 forms a fulcrum for the lever 5 when the main home
signal U MHS is locked and the loop home signal U L H S is free, as indicated
by dotted lines in Figure 2.
By these means one wire 7 is made to work the 2 signals UM HS and UL H S
in a simple and certain manner, unaffected by expansion or contraction of the wire.
The lowering of the rod 2 (signal U M HS) prevents the keys from being removed
from the lock U MHSL, and when the rod 1, (signal U L H S) is lowered, the
key cannot be removed from the lock U L HSL.
The down main and down loop home signals DMH and DLH S, are
worked in a similar manner by one wire 10, from the lever d on the station
platform, the down distant signal being worked by a wire 11 from the lever f
(Figure 1).
The up main and up loop starting signals U M S S and UL SS are worked
by a single wire 12 from the lever e and the down main and down loop starting
signals D M S S and DLSS are worked by a single wire 13 from the lever b.
These signals being locked by their respective locks U MS SL; ULSS L
and D MS SL; DLSSL; the arrangement in each case being as illustrated
by Figure 2.
The "lay-bye" or siding points locking box L B L (Figures 3, 4 and 5) consists
of a rectangular cast iron box having a slide 14 passing through it and on the
lower side of which are fixed locks 15 and 16 and a bolt 17 for locking the point
stretcher bars 18, 18, which move at right angles to the slide 14. The "lay-bye
or siding points are normally locked as shown for the loop line, and cannot he
unlocked or moved for the "lay-bye" or siding unless both keys are taken from
"

page_text: the key holes 27 (hereinafter referred to) of the main line locks UP'L and D PL
and inserted in the lay-bye or siding locks 15, 16 which can both be unlocked
and the slide 14 drawn to the shunting position which leaves the bolt 17 clear
of the stretcher bars 18, 18" so that the points may be set for either side.
While the keys remain in the locks 15, 16 neither the loop home nor the loop.
starting signals can be given.
The main line locking boxes U P L and D PL (Figures 6, 7, 8 and 9) each
consist of a rectangular cast iron box through which pass the switch stretcher
bars 19, 19. At right angles to these is a lower locking slide 20 and above the
latter and capable of moving parallel to the stretcher bars is the upper or "lay-bye
or siding locking slide 21.
The main line slide 20 has two locks 22, 23 and a rib 24 on its upper side
(to prevent straining the loop signal key 22 when the lay-bye key 27 is removed
aud inserted in the "lay-bye or siding points locking box L BL) and bolts 25, 26
on its lower side for locking the stretcher bars and points for the main or for the
loop line.
The "lay-bye" or siding slide 21 has one lock 27, a bolt 28, and two pairs
of suitably formed key hole slots 29, 30 and 31, 32 which allow the loop signal
keys to be got out only when the lay-bye or siding points are locked for the loop..
line and the keys from the locks 15, 16 are in the slide 21. The slots are however.
so formed as to allow the main line signal keys to be got out, even if the lay-bye.
or siding keys are removed from the slide 21, so as to enable trains to be run over
the main line if necessary, while shunting from the lay-bye or siding to the loop-
line is being done. The points are locked to either side by pulling or by pushing
the slide 20, which causes the bolt 25 or 26 as the case may be to engage in
the slot in the stretcher bars 19, 19ª and thus lock the switches without, strain....
on the locks.
Having described the several parts of the apparatus I shall now proceed to
explain the mode of operation of the same with reference to Figure 1 assuming by
way of example that an up train is to run through the station; say, on the main.
line B B the points being worked locally. In such a case the pointsman must first
set the up and down points for the main line B B. When this is done the slide 20.
of each locking box UPL and D P L can be pulled to lock the points. This
allows the up and down main line point keys 23 of both boxes to be turned to lock
the up and down point main slides 20. The key 23 of the up main locking
box U P L can then be inserted by the pointsman into the up main home signal
lock UM HSL; and the key 23 of the down main locking box D P L can be.
inserted into the up main starting signal lock U M S SL and the corresponding
signals UM HS and U M S S unlocked. Then the up main home signal UM HS,.
the up main starting signal U M S S, and the up distant signal UDS, can be
pulled off i.e. lowered to "line clear" from the station, thereby locking the keys 23, 23
in the locks UM HSL and UMSSL so that the up distant signal UD S.
back locks the up home signal U MH S.
Thus as will be seen, the points cannot be again moved until after the
signals U M H S, U M S S and U DS which have been lowered, are again all
placed at danger, so as to allow the keys 23 to be turned to lock the signals and
to be taken out. Even if these keys are out they cannot be put into the
locks U P L and D P L as long as the train is running over them.
Similarly with other combinations, the points must first be set correctly and
locked by drawing the locking slide before the keys which unlock the corre-
sponding signals can be removed. The lowering of any signal acts to lock
the key which is used to unlock it, until the said signal is again placed at.
danger."
$6
The down main home and up main starting signal locks, D MHS L
and UMSSL are opened by the same key which locks the down points for the
main line B B. The down loop home and up loop starting signals DLH S,.
and UL SS are opened by the same key which locks the down points for the

page_text: loop line CC. The locks of the up main and down main starting signals U MS S
and D M S S are similarly arranged so that six keys only are needed to fully
interlock all the points and signals. It will thus be seen that the signals cannot.
be lowered until the corresponding points are properly set and locked, and that
when the signals have been lowered, the points cannot be moved by the pointsmen
until the station master has again put the signals to "danger," so that all the
points and signals are controlled by the station master.
If desired the distant signals UDS and DDS may be worked locally by
levers at the main points since they cannot be lowered by the pointsmen until the
corresponding. home signal U MHS, ULH S, DM HS or DLHS has
first been lowered by the station master.
Having now particularly described and ascertained the nature of this inven-
tion as communicated to me, and in what manner the same is to be performed,
1 declare that what I claim is :-
1. Interlocking signals and points by means of keys substantially as described.
2. In railway signal apparatus a Hoating lever (such as 5) arranged so as to
operate the unlocked signal of two normally locked signals the said floating lever
working on the locked signal as a fulcrum whereby two signals can be worked by
one signal lever and wire connection.
ور
3. The " "lay-bye or siding points locking box, constructed arranged and
operating substantially as described with reference to Figures 3, 4 and 5 of the
drawings.
4. The main line points locking box constructed, arranged and operating
substantially as described with reference to Figures 6, 7, 8 and 9 of the
drawings.
Dated this 12th day of January 1897
J. C. MEWBURN & ELLIS,
55 and 56 Chancery Lane, London, Chartered Patent Agents.