Improvements in Railway Signalling Apparatus.
Year: 1896

page_text: Date of Application, 14th Aug., 1890
Complete Specification Left, 14th May, 1897-Accepted, 19th June, 1897
Complete Specification Left, 14th May, 1897-Accepted, 19th June, 1897
PROVISIONAL SPECIFICATION.
Improvements in Railway Signalling Apparatus.
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 that class of railway signalling apparatus which is
automatically controlled by a passing train, and has for its object to signal the
approach of a train from a distance, and is especially applicable in the case where
the train approaches a level crossing on a curved line not visible from the said
crossing.
The invention consists essentially of an electric gong or other audible signal
placed in a suitable position in an electric circuit so that an approaching train on
passing a given point operates a device to close the signal eirenit and thereby actuate
the signal, while the further passage of the said train past the crossing or other
desired point serves to break the said circuit and return the various parts to their
normal positions ready for future action.
In one arrangement of apparatus constructed according to this invention, and
especially applicable for a level crossing on a single line of railway, three treadle
bars are arranged so that the passage over either depresses it and closes an electric
circuit. The first treadle, or that one most distant from the crossing, when depressed
by a passing train approaching the crossing operates a contact or switch to close the
circuit of an electromagnet which being energised attracts its armature and causes a
tumbler contact lever to fall against an insulated contact plate. The passage of the
train over the second or middle treadle closes a second circuit so that the current
passes from a battery through the beforementioned tumbler contact and through a
second electromagnet similar to that before mentioned, which attracts its armature
and turns a second tumbler contact connected thereto against a contact plate the
current returning to the battery or to earth. The closing of the second tumbler
contact closes a circuit through a signal bell which signals the approach of the
train. The second or bell tumbler contact being closed, the bell continues to ring
until the train passes over the third treadle bar which closes an electric circuit
through two current breaking electromagnets similar and opposite to the two
beforementioned circuit closing magnets, the armatures of the contact closing and
breaking magnets being connected together in pairs so that the closing of the circuit
breaking magnet circuit causes the corresponding armatures to be attracted and
returns the armatures of the circuit closing magnets and the tumbler contact levers
to their normal positions and breaks the bell circuit.
The signal bell is not operated by the passage of a train in the opposite direction
to that for which it is arranged as it is necessary, in order to close the bell circuit,
that the first tumbler contact lever should first be placed in its closed position.
It will be obvious that by placing a set of treadles and connections on either side
of the crossing the signal bell will be operated on the approach of a train in either
direction.
In applying this invention to double lines of railway the first treadle, together
with the corresponding contact apparatus hereinbefore referred to, may be dispensed
with as all trains on either pair of rails travel in one direction only.
Dated this 14th day of August 1806
WHEATLEY & MACKENZIE,
40 Chancery Lane, Lordon, W.C., Agents.

page_text: Improvements in Railway Signalling Apparatus.
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 that class of railway signalling apparatus which is
automatically controlled by a passing train, and has for its object to signal the
approach of a train from a distance and is especially applicable in the case where
the train approaches a level crossing on a curved line not visible from the said
crossing. The invention consists essentially of an electric gong or other audible
signal placed in a suitable position in an electric circuit so that an approaching
train, on passing a given point, operates a device to close the signal circuit and
thereby actuate the signal, while the further passage of the said train past the
crossing or other desired point serves to break the said circuit and return the
various parts to their normal positions ready for future action.
In the accompanying sheet of drawings:-
Fig. 1 represents a diagrammatic plan of a signalling apparatus constructed
according to this invention as applied to a single line of railway.
Fig. 2 is a similar view as applied to a double line of railway, and
Figs. 3 and 4 are side and end elevations respectively of the circuit switching or
relay device.
As the operation of the apparatus in either direction of traffic is the same a
description of its action in one direction only will be sufficient.
Referring to Figs. 1, 3 and 4 a train approaching from the right hand direction
along the single line of rails A first passes over and actuates a treadle B of any
suitable construction, to close a circuit throngh magnet a which attracts its armature b
thereby throwing the tumbler contact lever c against the insulated contact plate d.
The train then in pass ng over treadle C completes a circuit through magnet a' and
contacted, the magnet a' attracting its armature and thereby putting the tumbler
lever cand plate di in contact and establishing a local bell circuit from battery X
through contacts ed' bell e and back to battery. On the train arriving at treadle D
near the crossing R contact is made and a circuit closed through magnets and f
which attract their armatures g g putting the tumbler levers ce out of contact with
their contact plates d d and thereby breaking the bell circuit. The hinged
armatures by are connected together by a rod engaging with the contact lever c.
As the advancing train passes over treadle C no current flows to restart the bell,
because the action of treadle C' depends upon the contact of the tumbler lever c' and
plate d' which necessitates the previous actaation by the train of the treadle B as
will be readily understood. The passage of the train over the treadle B' effects
nothing beyond preparing the relays for the next train by putting the lever c and
plate d in contact with each other.
Referring to Figs. 2, 3 and 4: A train approaching from the left hand direction
on the line of rails A first passes over and actuates treadle C to make contact and
close a circuit through battery X and magnet a which latter attracts its armature b
thereby pulling over tumbler contact lever c to form contact with the plate d. This
completes a local circuit from battery X through bell e, tumbler contact lever c,
contact plate d and back to battery. The bell then rings until the train passes
over treadle D which effects a contact, closing a circuit through magnet which
pulls over its armature g throwing the tumbler contact lever cover to its normal
position and breaking the bell circuit.
The action produced by the passage of a train in the opposite direction on the

page_text: other rails A will be precisely similar to that already described with reference to
line A as will be readily understood on reference to the drawings.
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. In railway signalling apparatus, an electric audible signal controlled by the
passage of a train, which operates contact devices to close relay circuits by means of
which the signal circuit is also closed or broken, substantially as described and for
the purpose set forth.
2. In railway signalling apparatus as applied to single lines of railway or where
traffic is in both directions, the combination with an audible electric signal of treadle
contacts B, C, B, C, D and of controlling relays, all arranged and connected,
substantially as described and shown in Fig. 1 of the drawings.
3. In railway signalling apparatus as applied to each line of a double line of
railway or where traffic is in one direction only the combination with an audible
electric signal of treadle contacts C, D), and of a controlling relay all arranged and
connected substantially as described and shown in Fig. 2 of the drawings.
4. In railway signalling apparatus, a relay comprising magnets af, hinged
armatures bg connected by bar h engaging with contact lever c, and insulated contact
plate d substantially as described.
5. In railway signalling apparatus the combination of an electric audible signal
with one or more relays substantially as described and shown and for the purpose
set forth.
Dated this 14h
1007
WHEATLEY & MACKENZIE,
40 Chancery Lane, London, W.C., Agents.