Improvements in or connected with Electric Railways of the Sectional Conductor Type.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in or connected with Electric Railways of the
Sectional Conductor Type.
I, FREDERICK CARLETON ESMOND, of 488, Fourth Street, Brooklyn, in the State of
New York, United States of America, Electrical Engineer, do hereby declare the nature
of my invention to be as follows:-
My invention relates to electric railways, wherein the electrically propelled
vehicle receives current from a series of insulated points or sections along the road-
way, which are automatically connected successively and temporarily with a well
insulated conductor along the road.
It consists in certain devices for securing the aforesaid automatic connections between
the said points or sections and the insulated main conductor, and maintaining the
same during the passage of the vehicle in a reliable and satisfactory manner without
the liability of the connection being maintained after the vehicle has passed, by reason
of any leakage current, and without liability of failure in establishing the con-
nection by reason of any accidental interruption of the circuit through the
vehicle.
More particularly I provide a shunt circuit from each of the points or sections to the
ground or return conductor, which contains a magnet which operates, when the collector
on the vehicle comes in contact with the corresponding point or section, to connect
the said point or section, directly to the main line through a connecting circuit con-
taining magnetic devices which operate so long as the main line current passes
through said connecting circuit to the vehicle, both to maintain the direct connection
between the point or section and the main line and also to interrupt and hold open
the aforesaid shunt circuit. By this means the shunt magnets operate in succession
to establish the direct connection between the respective points or sections and the
main conductor, while after the said connection is once established, the magnetic
devices therein maintain it during the passage of the vehicle and at the same time
the shunt circuit is open and remains open until after the vehicle has passed, when it
is again closed, ready for the next operation.
.
My invention is illustrated in the accompanying drawings, wherein
Figure I is a diagrammatic illustration thereof.
Figure II is a vertical section through the centre of a contact point and
shows, moreover, one form of the operating mechanism for establishing the desired
connections.
Figure III is a diagram showing the particular means to be employed for
securing the positive disconnection of the circuits after the vehicle has passed and
the means for preventing the accidental retention of the connection by leakage
currents, and
Figure IV shows a detail of the supplementary contact on the tip of the col-
lector bar.

page_text: Referring to Figure I, A, B, C and D represent insulated contact points along
the line of the roadway, along which passes the collector bar E on the vehicle,
having a length somewhat greater than the distance between the successive points,
so as to connect with them in succession and engage with each one before leaving the
one preceding. The collector bar E is connected with one terminal of the propelling
motor, whose opposite terminal is connected to the return conductor, which, in this
case, is the track rail.
Each of these points A, B, C and D is normally connected by a high resistance
shunt circuit leading to the track rail which serves as the return conductor. This
circuit may be traced from each contact point to the armature of a magnet H, thence
through a high resistance magnet G to the rail. Whenever the collector bar E comes
into contact with one of these points, for instance the point B, the current which the
collector bar is receiving from the preceding point, for instance point A, passes through
the described shunt circuit and energizes the magnet G, which thereupon attracts its
armature K. This armature K is connected at its pivotal point with the main insulated
conductor P, the connection being maintained in any desired manner as, for instance,
by a sort of knife-blade switch R. The opposite end of armature K comes into con-
tact with plate S, from which a direct connection passes to the point B'through the low
resistance magnet H and F. When, therefore, this circuit is completed the magnet F
will act to hold it closed, while the magnet H will act to open and hold open the shunt
circuit above described. Therefore, the current will flow from the main line P by the
direct circuit aforesaid to the collector bar E and thence to the motor on the vehicle
and will continue to flow until the collector bar passes off from the contact point, when
the magnets F and H will become de-energized and permit the parts to fall back into
their normal condition. In order that the accidental interruption of the circuit may
not cause a permanent interruption of current flow to the motor, I place on the vehicle
a motor generator T, having its motor end connected in a branch circuit between col-
lector bar E and the ground, while its generator end is connected to a set of storage
batteries V. In the event of any interruption of the circuit between the main
conductor P and the motor, the storage battery will work backward through the
motor generator T and deliver current both to the propelling motor and to the switch
magnet, so that the progress of the vehicle will not be interrupted and the connection
to the main line will be re-established at the next contact point."
Referring to Figure 3, it will be seen that the arrangement already described is also
present, but the shunt magnet G and the series magnet F have a common core, while,
on the same core, there is a third coil X wound oppositely to coils Fand G included in
a separate circuit leading from armature K to a leakage plate W which surrounds, but
is insulated from the corresponding contact point, for instance point A. This leakage
plate may be simply an enclosed box for the contact point, arranged slightly above the
surface of the roadway, as appears in Figure 4, but slightly below the level of the point
A, so that it can be touched momentarily by a supplementary brush E¹ on the
tip of the collector bar E.
It will be apparent that with this arrangement any leakage which there may be
from the point A to the return conductor will take place equally from the plate W, so
that the current from the main line P will flow first to the armature K and thence,
through the differential magnets X and F to point A and plate W and these magnets
will oppose each other and cause the magnet to drop its armature K and thus inter-
rupt the circuit. In this manner not only does the plate W form a short circuit
around the magnet F, but the current passing to the plate acts to positively oppose
the action of magnet F. Moreover, I produce this same differential action each 5
time that the collector bar leaves a contact point, by causing the supplementary
brush E¹ to strike the plate W. Therefore, the described differential action ensures
the disconnection of the rear contact point under all circumstances. The supple-
mentary brushes are placed at each end of the collector bar, but it is only the rear one
that has any effect, the forward one passing beyond the leakage plate before the 5
operation of the switch is required.
Referring to Figure 2, the contact point A is shown in the form of a hollow dome,

page_text: within which are enclosed the magnets F and G, the coils of the latter being wound
outside of those of the former. The armature K is in the form of a solenoid core,
common to the two coils. The circuit of shunt coil G is from the dome A
to the armature h and thence through the circuit breaker a to the magnet
and thence by wire d to the ground. The armature h is arranged to be
attracted by a projection from the interior of the magnetised dome, but the adjust-
ment is such that the dome will not be magnetised sufficiently to attract armature h
by the action of the coil G alone. When, however, the coil G attracts or draws up
armature K as described, it will energise the magnet F, as already explained, and the
line current passing through magnet F will be of sufficient strength to completely
magnetise the dome A and cause it to attract the armature and thereby open the
circuit of shunt magnet G in the manner described. The space enclosed by dome A
and the insulating material in which it is set, is divided into two compartments by
the horizontal insulating wall g. In the upper compartment are contained the
magnets and in the lower compartment the circuit closer, which is operated by the
armature K by means of a rod passing through a central opening in the said wall g.
The wire leading from the main conductor P passes up through the bottom
of the insulating base and is connected to a metallic frame f in the lower com-
partment from which it is conducted, when the switch is closed, through the magnet F
to the dome A.
Improvements in or connected with Electric Railways of the
Sectional Conductor Type.
I, FREDERICK CARLETON ESMOND, of 488, Fourth Street, Brooklyn, in the State of
New York, United States of America, Electrical Engineer, do hereby declare the
nature of my invention and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :-
My invention relates to electric railways, wherein the electrically propelled vehicle
receives current from a series of insulated points or sections along the roadway, which
are automatically connected successively and temporarily with a well insulated
conductor along the road.
It consists in certain devices for securing the aforesaid automatic connections
between the said points or sections and the insulated main conductor, and maintaining
the same during the passage of the vehicle in a reliable and satisfactory manner
without the liability of the connection being maintained after the vehicle has passed,
by reason of any leakage current, and without liability of failure in establishing
the connection by reason of any accidental interruption of the circuit through the
vehicle.
More particularly I provide a shunt circuit from each of the points or sections to
the ground or return conductor, which contains a magnet which operates, when the
collector on the vehicle comes in contact with the corresponding point or section, to
connect the said point or section, directly to the main line through a connecting circuit
containing magnetic devices which operate so long as the main line current passes
through said connecting circuit to the vehicle, both to maintain the direct connection
between the point or section and the main line and also to interrupt and hold open
the aforesaid shunt circuit. By this means the shunt magnets operate in succession

page_text: to establish the direct connection between the respective points or sections and the
main conductor, while after the said connection is once established, the magnetic
devices therein maintain it during the passage of the vehicle and at the same time the
shunt circuit is open and remains open until after the vehicle has passed, when it is
again closed, ready for the next operation.
My invention is illustrated in the drawings filed with the Provisional Specification,
wherein
Figure I is a diagrammatic illustration thereof,
Figure II is a vertical section through the centre of a contact point and shows,
moreover, one form of the operating mechanism for establishing the desired
connections.
Figure III is a diagram showing the particular means to be employed for securing
the positive disconnection of the circuits after the vehicle has passed and the means
for preventing the accidental retention of the connection by leakage currents, and
Figure IV shows a detail of the supplementary contact on the tip of the collector
bar.
Referring to Figure I, A, B, C, and D, represent insulated contact points along the
line of the roadway, along which passes the collector bar E on the vehicle, having a
length somewhat greater than the distance between the successive points, so as to
connect with them in succession and engage with each one before leaving the one
preceding. The collector bar E is connected with one terminal of the propelling
motor,, whose opposite terminal is connected to the return conductor, which, in this
case, is the track rail.
Each of these points A, B, C, and D is normally connected by a high resistance
shunt circuit leading to the track rail which serves as the return conductor. This
circuit may be traced from each contact point to the armature of a magnet H, thence
through a high resistance magnet G to the rail. Whenever the collector bar E comes
into contact with one of these points, for instance the point B, the current which the
collector bar is receiving from the preceding point, for instance point A, passes
through the described shunt circuit and energizes the magnet G, which thereupon
attracts its armature K. This armature K is connected at its pivotal point with the
main insulated conductor P, the connection being maintained in any desired manner
as, for instance, by a sort of knife-blade switch R. The opposite end of armature K
comes into contact with plate S, from which a direct connection passes to the point B
through the low resistance magnet H and F. When, therefore, this circuit is
completed the magnet F will act to hold it closed, while the magnet H will act to
open and hold open the shunt circuit above described. Therefore, the current will
flow from the main line P by the direct circuit aforesaid to the collector bar E and
thence to the motor on the vehicle and will continue to flow until the collector bar
passes off from the contact point, when the magnets Fand H will become de-energized
and permit the parts to fall back into their normal condition. In order that the
accidental interruption of the circuit may not cause a permanent interruption of
current flow to the motor, I place on the vehicle a motor generator T, having its
motor end connected in a branch circuit between collector bar E and the ground,
while its generator end is connected to a set of storage batteries V. In the event of
any interruption of the circuit between the main conductor P and the motor, the
storage battery will work backward through the motor generator P and deliver current
both to the propelling motor and to the switch magnet, so that the progress of the
vehicle will not be interrupted and the connection to the main line will be
re-established at the next contact point.
Referring to Figure III, it will be seen that the arrangement already described is
also present, but the shunt magnet G and the series magnet F have a common core,
while, on the same core, there is a third coil X wound oppositely to coils F and G and
included in a separate circuit leading from armature K to a leakage plate W which
surrounds, but is insulated from the corresponding contact point, for instance the
point A. This leakage plate may be simply an enclosing box for the contact point,
arranged slightly above the surface of the roadway, as appears in Figure IV, but

page_text: slightly below the level of the point A, so that it can be touched momentarily by a
supplementary brush E¹ on the tip of the collector bar E.
It will be apparent that with this arrangement any leakage which there may be
from the point A to the return conductor will take place equally from the plate W, so
that the current from the main line P will flow first to the armature K and thence
through the differential magnets X and F to point and plate W and these magnets
will oppose each other and cause the magnet to drop its armature K and thus
interrupt the circuit. In this manner not only does the plate W form a short circuit
around the magnet F, but the current passing to the plate acts to positively oppose
the action of magnet F. Moreover, I produce this same differential action each time
that the collector bar leaves a contact point, by causing the supplementary brush E¹
to strike the plate W. Therefore, the described differential action ensures the
disconnection of the rear contact point under all circumstances. The supplementary
brushes are placed at each end of the collector bar, but it is only the rear which
has any effect, the forward one passing beyond the leakage plate before the
operation of the switch is required.
Referring to Figure II, the contact point A is shown in the form of a hollow dome,
within which are enclosed the magnets F and G, the coils of the latter being wound
outside of those of the former. The armature K is in the forin of a solenoid core,
common to the two coils. The circuit of shunt coil G is from the dome A to the
armature h and thence through the circuit breaker a to the magnet and thence by
wire d to the ground. The armature his arranged to be attracted by a projection
from the interior of the magnetized dome, but the adjustment is such that the dome
will not be magnetized sufficiently to attract armature by the action of coil G alone.
When, however, the coil G attracts or draws up armature K as described, it will energize
the magnet F, as already explained, and the line current passing through magnet
F will be of sufficient strength to completely magnetize the dome A and cause it to
attract the armature h and thereby open the circuit of shunt magnet G in the manner
described. The space enclosed by dome A and the insulating material in which it is
set, is divided into two compartments by the horizontal insulating wall g. In the
upper compartment are contained the magnets and in the lower compartment the
circuit closer, which is operated by the armature K by means of a rod passing through
a central opening in the said wall g. The wire leading from the main conductor P
passes up through the bottom of the insulating base and is connected to a metallic
frame f in the lower compartment from which it is conducted, when the switch is
closed, through the magnet F to the dome A.
Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed, I wish it to be understood that I am
aware that in supplying electricity to electrically propelled vehicles by means of sectional
contacts in the roadway, the placing of guard plates or leakage plates between or
around the road contacts and connecting the said plates with the main conductor of
electricity through the same switches as the road contacts themselves has been previously
proposed and I make no claim to such leakage plutes per se, but I declare that what
I claim is :-
1. The described arrangement wherein the contact points or sections along an
electric railway are automatically connected, temporarily and successively to a well
insulated conductor, by means of a shunt magnet which first establishes a direct con-
nection between one of the said points and the well insulated conductor and whose
circuit is automatically interrupted at a subsequent period of time by the action of
the current passing through the direct connection aforesaid from the main conductor
to the contact point and is thereby maintained interrupted until the said current
ceases to flow.
2. The arrangement described wherein the insulated points or sections along the
line of an electric railway are automatically connected temporarily and successively
with the well insulated line conductor, by means of shunt and series magnets in the
manner described and wherein, also, the respective contact points are provided with

page_text: an adjacent leakage plate, arranged to divert any leakage current from the magnet
which maintains the connection aforesaid.
3. The described arrangement wherein a series of insulated contact points along
an electric railway are automatically connected successively and temporarily with a
well insulated line conductor by means of shunt and series magnets operating
as described and wherein, also, the series magnet is provided with a differential
opposing coil, which acts when energized to cause the release of the circuit closer
maintaining the described connection between contact points and conductor.
4. The combination with a series of insulated contact points along an electric
railway of the means described for automatically connecting them successively and
temporarily with a well insulated line conductor, including the shunt and series
magnet operating as specified, and a collector bar on the propelled vehicle, provided
with supplementary contacts, adapted to close the circuit of a differential magnetic
coil, which opposes the action of the circuit maintaining magnet and causes the latter
to release the circuit closer and open the described connecting circuit between
contact point and conductor.
5. The means described for operating the switches of an electric railway of the kind
described, in the event of an interruption in the flow of current from the line con-
ductor to the vehicle, consisting of a motor generator on the vehicle, arranged to be
operated by the line current and thereby charge a storage battery, the said storage
battery being adapted to work backward through the motor generator in the event of
the line current being interrupted and thereby generate a local current which
operates the propelling motor and the switches aforesaid.
For the Applicant,
J. G. LORRAIN, M.I.E.E.,
Norfolk House, Norfolk Street, London, W.C., Chartered Patent Agents.