Improvements in or connected with Signalling Apparatus for Railways.
Year: 1895

page_text: PROVISIONAL SPECIFICATION.
Improvements in or connected with Signalling Apparatus for
Railways.
I LEICESTER BRADNEY STEVENS, of Darlington Works, Southwark Bridge
Road, in the County of Surrey, Engineer, do hereby declare the nature of this
invention to be as follows:-
This invention relates to apparatus for controlling signals on railways and is
specially applicable for semaphore signals which are operated electrically from the
signal box, and has for its object to provide means whereby the passage of a train
over a given point causes a corresponding signal when occupying its "Line clear"
position to be automatically returned to ite normal or "danger" position. The
said invention consists essentially in causing the train when passing over the given
point to operate a contact breaker and thereby open an electric circuit controlling
a switch, which in its turn, controls the motor actuating the signal arms.
In one arrangement of apparatus constructed according to this invention a
switch controlling the electric motor actuating the signal arm is connected to a
hand lever carrying a cam which engages with a rocking detent, an extension of
which forms the armature of an electromagnet placed in an electric circuit in
which is also placed a contact breaker fixed in a convenient position to be operated
by a passing train.
When the signal arm is in its normal or "danger" position a contact spring
electrically connected to the beforementioned electromagnet rests on an insulating
block on the motor switch lever thereby breaking the magnet circuit. When,
however the motor switch lever is turned so as to close the motor circuit and cause
the motor to lower the signal arm, the said contact slides off the said insulating
block and makes contact with the switch lever or other conductor thereby
completing the electric circuit through the magnet which then attracts its
armature, and through the rocking detent and cam, locks the switch lever.
The passage of a train operates the aforesaid contact breaker so as to
momentarily open the magnet circuit, thereby freeing the armature and removing
the lock from the motor switch lever which is instantaneously returned to its
normal position by the beforementioned contact spring which again rests on its
insulator. After the passage of a train the contact breaker is again closed but as
the magnet contact spring then rests on its insulator the magnet circuit is broken,
the signal remaining at danger until the motor switch lever is again pulled over
by hand.
"
In order that the signal arm may be maintained in its normal or "danger'
position when the setting of the point lever locks requires it, a projèction
connected to the motor switch lever engages with a part of the point lever locking
connections and prevents the motor switch lever from being operated to lower the
signal arm.
In a modification of the above described arrangement the signal motor switch
lever is dispensed with, the motor switch being automatically operated to cause the
motor to lower the signal to "Line clear" by means of the bar or cam which
actuates the point lever locks.
Dated this 14th day of December 1895
WHEATLEY & MACKENZIE,
40 Chancery Lane, London, W.C., Agents.

page_text: Improvements in or connected with Signalling Apparatus for
Railways.
I LEICESTER BRADNEY STEVENS, of Darlington Works, Southwark Bridge
Road, in the County of Surrey, 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 apparatus for controlling signals on railways and is
specially applicable for semaphore signals which are operated electrically from the
signal box and has for its object to provide means whereby the passage of a train
over a given point causes a corresponding signal when occupying its line clear
position to be automatically returned to its normal or danger position.
The said invention consists essentially in causing the train when passing over
the given point to operate a contact breaker and thereby open an electric circuit
controlling a switch which, in its turn controls the motor actuating the signal
arms.
In the accompanying three sheets of illustrative drawings:
Fig. 1 shows an elevation of one lever apparatus and the requisite electric and
other connections constructed according to this invention, as applied to the
operation of a fixed line signal. Fig. 2 is a modification of the same.
Fig. 3 shows an arrangement of apparatus specially applicable for the block
system of signalling and
Fig. 4 is an enlarged view of the details of lever locking device.
Fig. 1 shows my invention as applied to the operation of a fixed line signal,
connected with the indication of two or more routes governed by switch points and
operated and suitably interlocked by the well-known lever interlocking mechanism.
Also the means I employ to suitably interlock my apparatus with the aforesaid
mechanism, so that both the switch and the switch lock levers must be properly set
before the corresponding signal can be lowered to safety. The action of thus
lowering the said signal prevents a reversal of the switch or the switch lock levers,
until a train accepting the said signal passes over an electric contact treadle in
advance of the signal, and in breaking an electric circuit, thereby releases a
magnetic detent which allows the signal operating handle to fly back, thus
breaking the circuit to the electro motor or similar device placed at the signal
post which in turn allows the fixed line signal to go to danger by gravity.
I also show a circuit breaking push button in connection with the said circuit, so
that in case of emergency, the signalman can break the circuit and put the signal
to danger.
The drawing shows my invention as applied to one signal but the other signal
shown in connection with the branch route could be operated by a duplicate
arrangement. In fact all the signals in connection with any arrangement of
switch points and interlocking may be so treated.
A is a lever operating the switch points s, and B is a lever which locks them by
the well known rod and bell-crank connections. These two levers are interlocked
with each other through the medium of the well known mechanism consisting of
the tappets a and b and the locks operated thereby in the locking box C. The
enlarged end of the rod G also interlocks with the locks in the box C in so far
that when levers A and B are in the position shown the end h is unobstructed and
can be lifted into the box. End h is however obstructed when levers A and B
occupy any other position than that shown.

page_text: In the positions shown the levers A and B stand so that the points a stand right
for the straight line, and are locked in that position.
All is clear then for lowering to safety the signal arm r, which governs the
straight line.
This is effected in the following manner.
The locks in the box C having been suitably adjusted by the tappets a and b
the end is free to be pulled up into the box. This is done by pulling out the
slide E to the dotted position which, rocking the bell crank F on the fulcrum f
lifts the rod G. The act of pulling out slide E also lifts the hooked lock J to the
dotted position. This lock J which previously prevented the action of the
handle K by obstructing the passage of the sector is held in one of two
determined positions by the slide E itself held in either its two extreme
determinate positions by means of a spring R engaging in corresponding notches
in the said slide as is clearly shown.
The free end of an insulated contact spring N rests on an insulator fastened to
sector but when the handle K is pulled over an electric circuit is completed from
battery Z to sector 1, spring N, magnet m m, treadle t signal motor E, and return.
Magnet m m attracts the detent M, which engaging one side of the sector / locks
handle K in the signal at safety position.
Slide E cannot now be pushed back owing to sector obstructing the passage of
book J, and as the end is in engagement with the lock box C, the levers A and B
cannot be reversed.
The line is thus safe for the train to accept signal r in its dotted position and
proceed.
When the engine passes over treadle t the contact at that point is broken. The
circuit through magnet m m is therefore broken, detent M is released, and
handle K flies back by action of tension spring k, thus again permanently breaking
the circuit at spring N and placing signal r at danger. Slide E may now be
pushed back locking handle K at and lowering the end of rod G out of
engagement with locks in box C. Levers A and B are then at liberty, if it is
desired to change the position of points, but if either lever is moved, the locking
in box C is caused to obstruct the upward passage of end by the well known
means thus effectually locking the lever K in the signal at danger position. If the
train or engine signalled does not proceed past the signal or in case of
emergency, the signalman by pressing push button P breaks the circuit, and
handle K flies back as before described.
The signal motor switch clectro mechanism is secured to an insulating base S
mounted on a pillar T secured to the lever locking frame W as shown.
In the modified arrangement shown in Fig. 2 the signal motor circuit is
controlled by the slide E alone, the switch lever K Fig. 1 being dispensed with.
The withdrawal of the said slide raising the rod G by means of cams 1 and 2 and
locks the point lever while at the same time the tooth 3 strikes the insulated tail 4
of the tumbler gravity armature 5 and causes it to fall against the contact 6, the
springs 7 at the same time making contact with the insulated contact plate 8
thereby completing the motor circuit. The passage of a train over treadle t
completes the circuit through magnet m which attracts armature 5 and again
breaks the motor circuit.
Figs. 3 and 4 show my invention as applied to the block system. In this
arrangement I provide means for controlling a fixed line signal, which is operated
by an electro-motor or similar device. The handle of the operating mechanism in
the signal cabin is released to fly back and put the signal to danger by exactly
the same means as described with reference to Fig. 1, so that train or engine
protects itself, by placing the block signal at danger on entering a block section.
In addition to this, I provide means whereby the operating handle is locked in
the signal at danger position until such time that the aforesaid train has passed
beyond the signal governing the entrance to the next section, and passing over an
electric contact treadle sends an electric impulse to the signal chain in the rear

page_text: energising an electro-magnet which releases the aforesaid lock. The operating
handle is then free and the signal it serves can be again lowered to admit a train
to the block section.
A. B. is a section of railway between two signals and . Under the block
system it is necessary that not more than one train should occupy the rails between
these two signals at one and the same time.
To this end I place electric contact treadles t and v about a train length in
advance of each block signal. Signal and treadle t are connected to the
apparatus at cabin A in exactly the same way as in Fig. 1., The condition of the
apparatus is that in which a train is supposed to be proceeding from A to B.
It has placed signal rat danger by passing over the treadle thus protecting
its rear.
Handle K can not be pulled over to again lower signal r to safety,
because its movement is arrested by detent J centred at P which engages the
sector l.
On the passage of train out of section A B it actuates treadle v which completes
an electric circuit from battery B through the coils of magnets which places
signal at danger. Its armature is attracted, and the free end striking against
the tail of detent J throws it back to the dotted position, where it remains
stable. Handle K being now released and another train being ready to enter
section A B said handle is pulled over to the dotted position, when detent M
engages it as before described in connection with Fig. 1. The signal is now at
safety and the train proceeding actuates treadle t which, breaking the circuit
through magnet m m allows handle K to spring back, thus putting signal r to
danger and becoming again locked by detent J in the following manner.
On reference to Fig. 4 it will be noticed that pin rides over the inclined pawl C
when handle K is pulled over. When however it flies back, the pin lifts the
pawl C the depending arm of which strikes against the short arm of spring lever d
and the other end thrusts detent J into engagement with sector l. The apparatus
is now in its first position again, and is operated for subsequent trains in precisely
the same way.
The signalman can at any moment put signal to danger by
pressing push button P as previously described.
There would be the usual bell signalling apparatus between station A and
station B.
I may prefer to use insulated rails instead of the treadles and v.
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:
1. The combination of electric contact handle K slide E and switch point
levers A and B whereby suitable interlocking between signal operating handle and
switch lock levers is accomplished.
2. The combination of treadle t with magnet and detent m M whereby signal and
signal lever K are placed at danger as soon as the train passes the signal.
3. The combination of electric contact lever K with detents M and J one of
which is released at the home station to put the signal and handle to danger aud
the other is released from the distant station to allow the signal to be again
lowered.
4. The arrangement and construction of signal motor switch electro-mechanism
substantially as described with reference to Fig. 1 of the drawings.
5. The improvements in or connected with signalling apparatus, the whole
arranged, constructed and operating substantially as described and shown in Fig. 1
of the drawings.
6. The arrangement and construction of signal motor switch electro mechanism
substantially as described with reference to Fig. 2 of the drawings.
7. The improvements in or connected with signalling apparatus, the whole
arranged constructed and operating substantially as described and shown in Fig. 2
of the drawings.

page_text: 8. The arrangement and construction of sigual motor switch electro mechanism
substantially as described with reference to Figs. 3 and 4 of the drawings.
9. The improvements in or connected with signalling apparatus, the whole
arranged, constructed and operating substantially as described and shown in Figs. 3
and 4 of the drawings.
Dated this 14th day of September 1896.
WHEATLEY & MACKENZIE,
40 Chancery Lane, London, W.C., Agents.