Improvements in Semaphore Signalling Apparatus for Railways.
Year: 1895

page_text: Date of Application. 20th June, 1895
Complete Specification Left, 20th Mar., 1896-Accepted, 9th May, 1896
PROVISIONAL SPECIFICATION.
Improvements in Semaphore Signalling Apparatus for Railways.
I LEICESTER BRADNEY STEVENS, Engineer of Darlington Works, Southwark
Bridge Road, in the County of London, do hereby declare the nature of this
invention to be as follows:-
This invention has for its object to construct semaphore signalling apparatus for
railways in such manner that it may be operated electrically from a distance either
automatically by a passing train, by a suitable switching arrangement connected to
and operated by ordinary point levers or other operating device or by a suitable
hand switch arrangement, and thus dispense with the usual mechanical connections,
and consists essentially in connecting the semaphore arm by means of an electrically
controlled friction or other coupling to an actuating device comprising an electric
motor whose armature engages with the said friction coupling on the closing of the
motor circuit and, the coupling circuit being closed, causes the semaphore to be
lowered, while the breaking of the coupling circuit causes the disengagement of the
said coupling which allows the semaphore to be automatically returned, by means
of its counterweight, to its normal or "danger" position.
In one arrangement of signalling apparatus constructed according to this
invention the semaphore arm, with or without the usual spectacle glasses, is rigidly
mounted on a carrying spindle working in suitable bearings on the signal post. On
the said spindle is also rigidly mounted a frame in which slide radially electro-
magnets whose outer pole pieces when energised by a current are attracted to the
inner cylindrical surface of a coupling drum loosely mounted on the aforesaid
carrying spindle, the friction between the said pole pieces and drum thereby
locking them and the semaphore arm together.
Connected to, or forming part with, the aforesaid coupling friction drum is a
ratchet wheel whose teeth are engaged by a pawl connected to the oscillating
armature of an electromagnet so that at each such oscillation the ratchet wheel is
advanced one or more teeth.
It will thus be seen that on breaking the electric circuit through the coupling
magnets the attraction, and consequently the friction, between their polar
extensions and the coupling drum ceases, the signal arm being automatically
returned, by means of its counterweight or by other suitable means, to its normal
or "danger" position. It will be obvious that the smooth surfaces of the coupling
friction drum and the polar extensions of the coupling magnets may be replaced by
ratchet teeth or other suitable form of roughened surface; also, the pawl and
ratchet wheel may be replaced by a nipping arrangement or other equivalent
device.
The motor magnet circuit is controlled by a lever make and break device
connected to the armature. The said lever carries a contact shoe sliding on a
contact plate and adjustable along its length to enable the length of contact, and
consequently the duration of the motor energising current, to be varied to suit
requirements. In order that the motor circuit may be closed during the forward
oscillation of the armature and broken during the return oscillation, a projection on
the contact lever is guided by a cam provided with a trap lever which latter during
the forward oscillation is raised by the said projection, which on its return, travels
over the said trap lever thereby lifting the contact lever out of contact with its
plate.

page_text: In order to operate the signal automatically by a passing train from a distance a
contact maker is provided comprising a series of levers whose long and short arms
are connected together alternately, the shorter arm of one outer lever being
connected to a rail, while the longer arm of the opposite outer lever carries a spring
contact plate which, on a slight depression of the rail, is caused to move through a
considerable distance and make contact, thereby closing the electric circuit as will
be readily understood.
The automatic closing of the signal motor and coupling circuits as above
described serves to start the signal actuating mechanism, its further action being
continned by the said circuits being kept closed for any predetermined period by
means of a suitable contact arrangement operated by the motor armature.
Instead of the electromagnets and pawl arrangement herein before described one
or more solenoids may be used with their cores connected to the drum on the
semaphore spindle by a chain band or other suitable connection.
Dated this 20th day of June 1895.
WHEATLEY & MACKENZIE,
40 Chancery Lane, London, W.C., Agents.
COMPLETE SPECIFICATION.
Improvements in Semaphore Signalling Apparatus for Railways.
I LEICESTER BRADNEY STEVENS, Engineer, of Darlington Works, Southwark
Bridge Road, in the County of London, 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 has for its object to construct semaphore signalling apparatus for
railways in such manner that it may be operated electrically from a distance
either, automatically by a passing train, by a suitable switching arrangement
connected to and operated by ordinary point levers or other operating device, or
by a suitable hand switch arrangement, and thus dispense with the usual mechanical
connections; and consists essentially in connecting the semaphore arm by means
of an electrically controlled friction or other coupling to an actuating device
comprising an electric motor whose armature engages with the said friction
coupling on the closing of the motor circuit and, the coupling circuit being closed,
causes the semaphore to be lowered while the breaking of the coupling circuit
causes the disengagement of the said coupling which allows the semaphore to be
automatically returned by means of its counterweight to its normal or "danger'
position.
In the accompanying five sheets of illustrative drawings :-
"
Fig. 1 is a side elevation of one arrangement of semaphore signalling apparatus
constructed according to this invention, and Fig. 2 is an end elevation of the same.
Fig. 3 is a side elevation, Fig. 4 a plan, and Fig. 5 an end elevation of a modified
arrangement of motor apparatus, Fig. 6 is an elevation of a simplified arrangement
of the same and Fig. 7 is a vertical section of magnetic friction coupling.
Fig. 8 is a side elevation, Fig. 9 a plan and Fig. 10 an end elevation of a further
modified arrangement of motor apparatus for operating the signal arm, and
Fig. 11 is a diagram showing the electrical connections on the same.
Figs. 12 and 13 are sectional elevation and sectional plan of a contact breaker
adapted to be operated automatically by a passing train.
In the arrangement of signalling apparatus constructed according to this
invention shown in Figs. 1 and 2 the semaphore arm a, with or without the usual
spectacle glasses, is rigidly mounted on a carrying spindle & working in suitable
bearings on the signal post d. On the said spindle 6 is also rigidly mounted a
frame e in which slide, radially, electromagnets ƒ whose outer pole pieces g when

page_text: energised by a current, are attracted to the inner cylindrical surface of a coupling
drum loosely mounted on the aforesaid carrying spindle, the friction between
the said pole pieces and drum thereby locking them and the semaphore arm
together.
Connected to or forming part with the aforesaid coupling friction drum h is a
ratchet wheel whose teeth are engaged by pawls connected to the oscillating
armature m of an electromagnet n so that at each oscillation the ratchet wheel is
advanced one or more teeth, all backward motion being prevented by the nipping
cam 0.
It will thus be seen that on breaking the electric circuit through the coupling
magnets the attraction, and consequently the friction, between their polar
extensions 9 and the coupling drum ceases, the signal arm a being then
automatically returned by means of its counterweight or by other suitable means,
to its normal or "danger" position. It will be obvious that the smooth surfaces
of the coupling friction drum and the polar extensions of the coupling magnets may
be replaced by ratchet teeth or other suitable form of roughened surface, also the
pawl and ratchet wheel may be replaced by a nipping arrangement or other
equivalent device.
The motor magnet circuit is controlled by a lever make and break device
connected to the armature. The lever p carries a contact shoe q sliding on a
contact plater and adjustable along its length to enable the length of contact, and
consequently the duration of the motor energising current, to be varied to suit
requirements. In order that the motor circuit may be closed during the forward
oscillation of the armature and broken during the return oscillation, a projection s
on the contact lever displaces a trap lever during the forward oscillation, and is
caused on its return to travel over the said trap lever, thereby lifting the contact
shoeg out of contact with its plate.
The two poles of the controlling battery are connected through two insulated
terminals v, wo to the coils of the magnets and to two insulated terminals x, y
connected to the contact stop and plate a respectively. The terminal a is
connected to the contact plater while the other y connected to the coils of the
magnet n which are also connected to the armature.
The action of the apparatus is as follows:-
The main circuit being closed by hand or automatically, current flows through
the coupling magnet coils / magnetising their cores g and locking the frame e and
drum h together. At the same time current flows through terminal x, contact
plate r, lever p, armature m, motor magnet coils n, terminals y, v, back to the
battery line. The armature m is attracted by the magnet n, the pawls / moving
the drum h through one step when the pin s passes beneath the trap levert and the
shoe g slides out of contact with the plater the circuit of motor magnet n being
thereby broken and its armature m being returned to its normal position by its own
weight and the spring b¹.
The armature m in returning to its normal position carries with it the contact
lever p, the projection s traversing the upper side of the trap levert and thereby
lifting the contact shoe g free of its plate r until the completion of the return
oscillation of the armature, when the projections, falling off the lever t, permits
them to again make contact.
The above described operation is repeated until the signal arm a is sufficiently
lowered when the frame e strikes the contact spring a' and presses it against the
contact point z, thereby cutting out the magnets n as will be readily understood.
On breaking the main or battery circuit the cores g of the coupling magnets are
demagnetised and the arm a is returned to its normal or "danger" position by
counterweights or other suitable means.
In the modified arrangement shown in Figs. 3, 4 and 5 the ratchet mechanism is
dispensed with, the armature c¹ being connected directly to the shaft b working in
bearings c and carrying the semaphore arm a by means of a chain or band d¹.
When the arm a has been pulled down by the magnets e¹ they are cut out, the

page_text: armature e¹ being then held in that position by the small magnets f¹ acting on the
armature extension g', until the controlling circuit is broken, as will be readily
understood.
In the arrangement shown in Figs. 6 and 7 one double magnet and armature i
only are employed.
The semaphore arm a is mounted on a shaft b connected by a chain d', or
equivalent, to the armature ¹ actuated by the magnets . When the arm a has
been pulled down by the magnets h¹, the shaft is held in that position by a
magnetic clutch which comprises an end bearing m¹ secured to the frame n' and
on which is securely mounted a wound bobbin of with core p¹. On the shaft bis
mounted a disc q¹ free to slide, axially, but prevented from turning thereon by a
key or other suitable means. It will thus he seen that on passing a current through
the coil of the disc.q' is attracted to the fixed core p₁ of the magnet, the end
bearing m¹ and shaft being thereby effectually locked together until the breaking
of the magnet circuit.
In the modified arrangement shown in Figs. 8, 9, 10 and 11 the motor is detached
from the semaphore arm and is connected thereto by means of a cord or chain.
The motor comprises an armature working in field magnets s and provided
with a commutator t', brushes v' and shaft w¹ turning in suitable bearings . On
the end of the shaft w is mounted a pinion y¹ gearing with a spur wheel mounted
on a shaft a² and secured to an electromagnet inside the cover c² the ends of
whose coil are connected to two insulated rubbing pulleys d²² on which two spring
contact plates 2 92 press. Facing the pole 2 of the said electromagnet is a
disc secured to or forming part with the sleeve 12 mounted loosely on the
spindle a² and forming a barrel on which a cord or chain m² for operating the signal
arm is wound. It will thus be seen that when the aforesaid magnet is energised
by a current the disc 2 is attracted to its core and the sleeve 12 and spur wheel
are securely locked together. A cylindrical roller ³ running in an inclined race o²
permits of the rotation of the spur wheel in one direction, so as to wind the cord m³
on the barrel, but effectually prevents its rotation in the opposite or backward
direction. Mounted on or otherwise secured to the sleeve 2 is a pinion p² gearing
with a pinion 2 having a screw threaded boss 2 fitting between standard checks 2
and mounted on a screw threaded spindle 2 having a square part sliding in a
guide to prevent its rotation, so that the rotation of the said pinion in either
direction causes the spindle t² to slide in a corresponding direction and so remove
the spring contact plate w² from the contact point, or vice versa, to open or close
an electric circuit as will be hereinafter explained.
On the end of the apparatus is arranged a relay comprising an insulated electro-
magnet y and contact plate 2 which, when the circuit through the magnet y² is
closed, are attracted, their contact closing the circuit of a local battery for operating
the apparatus in the following manner.
Referring to the diagram, Fig. 11 :—The signal being at its normal or "danger"
position the relay circuit is open, the barrel is in its normal position and the
spindle 2 and contact plate w² are in their normal positions as shown in the
drawings, and the sleeve or barrel 2 and spur wheel are disconnected. In order
to lower the signal arm into its "line clear" position the relay circuit is closed by
hand or otherwise, thereby energising the relay magnet y which attracts the
contact plate and thereby closes the circuit of a local battery A. The current
then passes through contact plate 22, core of magnet y³, armature r, field magnets,
contacts w², a, back to battery A. A second circuit passes from the magnet y' to
contact plate 92, pulley 2, through coil of coupling magnet 62, pulley d², plate f³,
and back to battery. Thus the current through the coupling magnet locks the
barrel and armaturer together, while that through the motor armature etc. causes
the sleeve or barrel to be rotated and wind up the cord connected to the
semaphore arm and thereby lower it to "line clear" position. The rotation of
the barrel causes the screwed spindle t², by means of the connecting pinions p³ ³
to slide forward and when the signal arm is sufficiently lowered, push the plate w

page_text: 66
off its contact point x² and break the motor circuit; but as the coupling circuit is
still closed the signal arm is held down until the relay circuit is broken when, the
coupling being disengaged, the semaphore arm is returned to its normal or
danger" position by its counterweight or other means, the cord m² being thereby
unwound from the barrel 12 and the spindle ² and contact plate wo² returned to
their normal positions as will be readily understood. To prevent water from being
conveyed to the motor by the cord m² it is first passed under a guide roller a³
beneath it.
In order to return the signal arm to its normal position automatically from a
distance by the action of a passing train, a contact breaker placed in the motor
circuit is provided comprising a series of levers 63 fulcrumed in bearings and
whose adjacent long and short arms are connected together alternately, the shorter
arm d³ of one outer lever being connected to a rail e³, while the longer arm f³ of
the other outer lever carries a contact point g³ engaging with an insulated spring
contact plate ³ connected to the controlling circuit, and which, on a slight down-
ward movement of the arm d³, is caused to move through a considerable distance
and break contact, thereby breaking the electric circuit. The end of the arm d³
rests against the flat end of a screwed rod 3 adjustably secured in the jaws of the
bracket 13, itself secured to the rail e by two nuts m³, a bolt n³, passing through the
jaws, preventing the rod from becoming detached therefrom. The arm d³ is kept
in contact with the bottom of the rod and the levers ³ are returned to their
original position after being operated by means of a counterweight 3 on the arm f³.
The lever mechanism is enclosed in a cover o³ through the lid of which the rod 3
passes, and is suitably guided by the bush p³. It will be obvious that with trifling
modifications this circuit breaking device may be adapted as a circuit closer.
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 semaphore signalling apparatus for railways, operating the signal arm by
means of an electric motor connected to the said arm by an electromagnetic
coupling, substantially as described.
2. A semaphore signalling apparatus for railways, arranged, constructed, and
operating substantially as described and shown in Figs. 1 and 2 of the
drawings.
3. A semaphore signalling apparatus for railways, arranged, constructed, and
operating substantially as described and shown in Figs. 3, 4 and 5 of the
drawings.
4. A semaphore signalling apparatus for railways, arranged, constructed, and
operating substantially as described and shown in Figs. 6 and 7 of the
drawings.
5. A semaphore signalling apparatus for railways, arranged, constructed, and
operating substantially as described and shown in Figs. 8, 9, 10 and 11 of the
drawings.
6. In semaphore signalling apparatus for railways, a contact making or breaking
device arranged, constructed, and operating substantially as described and shown
in Figs. 12 and 13 of the drawings.
Dated this 20th day of March 1896.
WHEATLEY & MACKENZIE,
40 Chancery Lane, London, W.C., Agents.