Improvements in or
Year: 1896

page_text: Pate of Application (in United Kingdom), 11th Apr., 1896
Complete Specification Left, 11th Jan., 1897-Accepted, 13th Feb., 1897
PROVISIONAL SPECIFICATION.
Improvements in or
I, FREDERICK CARLETON ESMOND, of 45 Broadway, New York City, United
States of America, Electrical Engineer, do hereby declare the nature of this invention
to be as follows:-
The present invention relates to electric traction systems of the kind in which there
are one or more insulated line conductors, and a series of exposed working conductor
sections or points normally disconnected from the line conductors, but coupled in
circuit therewith through automatically acting electro-magnetic switches for supplying
current to the motors on the travelling car.
The invention comprises a number of improvements in systems of this character,
among which I mention as prominent :-
First A series of magnets for actuating the line switches, whose windings are
connected to the contacts or line conductor, or both, at an intermediate point so as to
reduce the ohmic losses in the magnet coils and simplify their construction. This
feature of the present invention can be used in a wide number of systems, some of
which will be hereinafter described.
Second: It is already well known that the line switches may be operated by
throwing in advance conductor sections by an arrangement of circuits such that the
current from a given contact point or set of contact points divides, one branch leading
directly to the motor, and another branch in multiple passing through the magnet of
an advance switch or set of switches. In this invention I so arrange the circuits that
the current does not divide, but flows through the magnet of an advanced set of
sections in series with the motor. This is a preferable construction for practical
purposes.
Third I show herein as a part of my invention, a system in which the working
contacts are divided into sets of three, and in order to simplify the line construction,
as well as to ensure complete insulation between different sets of sections, I provide a
comparatively long space between each set of sections, equal or substantially equal to
the distance which can be bridged by two of the collectors or two parts of a single
collector, as herein described.
The invention also comprises other features which will be hereinafter described.
In the accompanying drawings Fig. 1 is a diagram illustrating one form of the
invention, and
Fig. 2 a diagram of a similar form of the invention with the circuits somewhat.
changed.
Fig. 3 is still a further modification.
Fig. 4 is a diagram showing a different system, in which some of the features of the
invention may be embodied, and

page_text: Fig. 6 is still a further modification.
Referring first to Fig. 1, A and B are the insulated line conductors. For the
purpose of this description I will assume that A is the positive supply conductor. It
will be insulated and arranged along the track in any of the ways now well known in
the art. The negative supply conductor B may consist of a metallic wire or track
rails or bonded track rails connected to a feeder, in the manner now customary in the
ordinary trolley system. 1, 2, 3, and 4, 5, 6, are the working conductor sections,
which are arranged in sets of three, as shown in the diagram. S, S' are switches,
which normally stand in an open position under the action of gravity or a spring s,
but when closed make contact with the supply conductor A through contact
points t, . M, M' are electro-magnets, one for each switch. The winding of each
of these magnets is connected, as shown in the diagram, to the line switch at one
terminal, to one of the working contacts, as 2, at the other terminal, and at an inter-
mediate point to the other working contacts of each set, as, for example, 1, 3.
The winding of magnet M' is similarly connected to the switch S¹ and to the
contacts 4, 5, 6.
The motor or motors on the car are diagrammatically represented as comprising an
armature D and field coil F. One terminal of the motor is connected to the return
conductor B through the. wheels of the car or a special contact. device G. The positive
terminal of the motor is maintained in circuit with the working, contacts. through
overlapping collectors, comprising members a, b, which are electrically connected
by the wire c, and a second set of parts e, f, connected by the wire g.
When the parts are in the position shown in the diagram, and with the car
moving in the direction of the arrow, the switch S has been closed and current flows
from the line conductor A, through the switch, a comparatively small portion of the
winding of magnet M, the collector: a, collector b, through a portion of the
winding of magnet M', through the collector f, and to the positive terminal of
the motor through a switch s A portion of the winding of magnet M will
therefore be included in series circuit with the motor so as to close switch S.
This switch, however, is shown open in the diagram for clearness of illustration.
The switch S having once been closed, little power is required to maintain it
closed, hence a comparatively few turns on magnet M are now in circuit, while
a larger number of turns of magnet M₁ are in circuit so as to afford the greater
power necessary for primarily closing this switch. For this reason I ordinarily
tap the coils at a point about two-thirds of their length, so that the line current
collected from one set of sections has to pass only through a small number of
turns, while each magnet is primarily energized by current passing through a
larger number of turns. I do not, however, limit the invention to this special
arrangement.. By the time that the collector a leaves the contact 3 the collector e
will have engaged the contact 4, so as to preserve the motor circuit constant.
will thus be seen that for a considerable length of time the current has to pass from
one of the rear sets of contacts in series through a portion of the winding of the
magnet of
an advanced set of contacts, when the rear set is disconnected
and current is collected through the advance switch. In this way, as will be
evident, the switches are successively thrown, and the motor circuit is preserved
constant.
It
A storage battery, or other source of current, H is carried on the car, and is
connected at one terminal to the positive motor terminal through a resistance I.
The other terminal of the battery is connected through switches, with either set
of collectors. The purpose of the battery is to pick up the switches at any time when
it becomes necessary so to do. For example, assume that it is necessary to pick up
the switch S' when the car stands in the position shown. The switch would then
be thrown onto the contact t2, and the switch s¹ onto the contact to. The circuit
would then be formed from the battery through the contact t², collector f, a portion of
magnet M, collector b, contact to and switch S'. At other times, when the car is
moving in the opposite direction, a similar circuit would be formed by throwing the

page_text: switch onto the contact t, and the switch S onto the contact to. If at any time it
is desired to charge the battery from the line this may be done, for example, by
throwing the switch onto contact, when the line current would pass partly through
the battery and partly through the magnet circuit as heretofore traced.
If the
car be moving in the opposite direction a similar result would be secured by
throwing the switch a onto the contact t'.
The two sets of line contacts are separated, as shown in the drawing, by a
substantial distance, approximately equal to that which would be bridged by two
of the collecting parts. This secures good insulation, and saves also somewhat in the
number of working contacts.
The system of Fig. 2 is very similar to that of Fig. 1, except that the line
switches S, S', are connected to an intermediate point in the coils of the magnets,
while two of the working contacts of each set are connected to one terminal of
the magnet, and the third working contact to the other terminal. This will be
readily understood froin the drawing, as will also the mode of operation.
The system shown in Fig. 3 resembles that of Fig. 1, except that the working
sections instead of being short points are made of rail sections, and the collectors
are formed of wheels or short brushes. The two systems resemble one another so
closely that the mode of operation of the modification shown in Fig. 3 will be
understood without explanation. The parts are lettered in the same way as in
Fig. 1, and the car is shown in the corresponding position. For an ordinary
twenty-four foot car in this system the rail sections will be about three feet in
length, or a little less, and the distance between adjacent sets of sections will be
approximately equal to one rail section.
In Fig. 4 there is shown a system where the switching magnets are arranged
so as to have the same function as in Fig. 1, but the line contacts are disposed
in sets of two each. With the purts in the position shown, the circuit extends
from the positive conductor A, through the magnet M, collector a, collector b,
through a portion of the magnet M', collector f, switch s', through the motor and
through the return conductor B. A portion of the winding of magnet M¹ is
now in series with the motor, and will close the switch S'. In this modification
the line current will, however, have to pass through the entire winding of one of
the magnets for a greater portion of the time than in the system of Fig. 1, and
I regard the system of Fig. 1 as a preferable one. The arrangement of the
storage battery and the collectors is substantially the same as has been already
described.
In Fig. 5 a similar system is shown, except that the switches S, S' are connected to
an intermediate point in the coils of the magnet, the terminals of-the magnets being
connected to the contacts. In this case the normal line current will pass through
only a fraction of the magnet, while the current actuating the switch will pass
through the entire coil. In this particular the arrangement is the reverse of that
of Fig. 4.
In Fig. 6 I show how this feature of the invention can be embodied in a somewhat
different system. Here the contacts are arranged in pairs, one opposite another,
instead of being disposed one after the other along the road bed, as in Figs. 4 and 5.
The contacts of each pair are connected to the terminals of the magnets M, M', and
the switches S, S' lend to an intermediate point in the coils. The arrangement of the
collectors is also somewhat modified. A long collector, a³, which will bridge the
distance between two sets of contacts, is connected to the positive motor terminal and
is adapted to engage one set of contacts, as 2' and 4. Another collector, *, engages
the contacts 1', 31, and normally will be connected through a switch to one or the
other of two accessory collectors &', which are arranged in line with collector a,
but separated therefrom by insulating breaks. With the parts in the position shown
current will pass from the line conductor A, through the collector as, to the motor so
long as the collector a preserves contact with the contact point 2. When, however,
the collector a leaves this contact current then passes from the contact 21 to the
collector 6, collector &, contact 3, the whole of magnet M' and collector a³ to

page_text: the motor thus throwing the advance magnet in series with the motor circuit. When
the car travels in the opposite direction the switch & will be thrown onto the contact t²;
and a similar circuit for actuating the line switches will be formed, as will be
understood.
Improvements in or connected with Electric Traction.
I, FREDERICK CARLETON ESMOND, formerly of 45, Broadway, New York City,
now of 488, Fourth Street, Brooklyn, New York, United States of America,
Electrical 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 :-
The present invention relates to electric traction systems of the kind in which there
are one or more insulated line conductors, and a series of exposed working conductor
sections or points normally disconnected from the line conductors, but coupled in
circuit therewith through automatically acting electro-magnetic switches for supplying
current to the motors on the travelling car.
The invention comprises a number of improvements in systems of this character,
among which I mention as prominent ;-
First: A series of magnets for actuating the line switches, whose windings are
connected to the contacts or line conductor, or both, at an intermediate point so
as to reduce the ohmic losses in the magnet coils and simplify their construction.
This feature of the present invention can be used in a wide number of systems, some
of which will be hereinafter described.
Second: It is already well known that the line switches may be operated by closing
the circuit through the working conductor sections which are in advance by means of
an arrangement of circuits such that the current from a given contact point or set of
contact points divides, one branch leading directly to the motor, and another branch
in multiple passing through the magnet of an advance switch or set of switches.
this invention I so arrange the circuits that the current does not divide, but flows
through the magnet of an advance set of sections in series with the motor. This is a
preferable construction for practical purposes.
Third I show herein as a part of my invention, a system in which the working
contacts or sections are divided into sets of three, and in order to simplify the line
construction, as well as to insure complete insulation between different sets of sections,
I provide a comparatively long space between each set of sections, that is to say one
equal or substantially equal to the distance which can be bridged by two of the
collectors carried by the car or two parts of a single collector, as herein described.
The invention also comprises other features which will be hereinafter described.
In the drawings which were left with the Provisional Specification,
Figure 1 is a diagram illustrating one form of the invention, and
Figure 2 a diagram of a similar form of the invention with the circuits somewhat
changed.
Figure 3 is still a further modification.
Figure 4 is a diagram showing a different system, in which some of the features of
the invention may be embodied, and

page_text: Figure 6 is still a further modification.
Referring first to Figure 1, A and B are the insulated line conductors. For the pur-.
pose of this description I will assume that A is the positive supply conductor. It will be
insulated and arranged along the track in any of the ways now well known in the art..
The negative supply conductor B may consist of a metallic wire or track rails or
bonded track rails connected to a feeder, in the manner now customary in the
ordinary trolley system. 1, 2, 3, and 4, 5, 6, are the working conductor sections,
which are arranged in sets of three, as shown in the diagram. S, S' are switches
which normally stand in an open position under the action of gravity or a spring s,.
but when closed make contact with the supply conductor A through contact points t, t¹.
M, M are electro-magnets, one for each switch. The winding of each of these
magnets is connected, as shown in the diagram, to the line switch as S at one terminal,
to one of the working contacts, as 2, at the other terminal, and at an intermediate-
point to the other working contacts of each set, as, for example, 1, 3. The winding.
of magnet M' is similarly connected to the switch St and to the contacts 4, 5, 6.
The motor or motors on the car are diagrammatically represented as comprising
an armature D and field coil F. One terminal of the motor is connected to the
return conductor B through the wheels of the car G or a special contact device...
The positive terminal of the motor is maintained in circuit with the working contacts
through overlapping collectors, comprising members a, b, which are electrically
connected by the wire c, and a second set of parts e, f, connected by the wire g.
When the parts are in the position shown in the diagram, and with the car moving
in the direction of the arrow, the switch S has been closed and current flows from
the line conductor A, through the switch, a comparatively small portion of the
winding of magnet M, working contact 3, the collector a, wire c, collector b, contact 4,
and
through a portion of the winding of magnet M', through the collector f, wire g,
to the positive terminal of the motor through a switch s'. A portion of the winding
of magnet M' will therefore be included in series circuit with the motor so as to close-
switch S. This switch, however, is shown open in the diagram for clearness of
illustration. The switch S having once been closed little power is required to maintain
it closed, hence a comparatively few turns on magnet M are now in circuit, while a
larger number of turns of magnet M' are in circuit so as to afford the greater power
necessary for primarily closing this switch. For this reason I ordinarily tap the
coils at a point about two-thirds of their length, so that the line current collected
from one set of sections has to pass only through a small number of turns, while
each magnet is primarily energized by current passing through a larger number
of turns. I do not, however, limit the invention to this special arrangement. By
the time that the collector a leaves the contact 3 the collector e will have engaged
the contact 4, so as to preserve the motor circuit constant. It will thus be seen
that for a considerable length of time the current has to pass from one of the rear
sets of contacts in series through a portion of the winding of the magnet of an
advanced set of contacts, when the rear set is disconnected and current is collected
through the advance switch. In this way, as will be evident, the switches are
successively closed, and the motor circuit is preserved constant.
. A storage battery, or other source of current, H, may be carried on the car,
and connected at one terminal to the positive motor terminal through a resistance I.
The other terminal of the battery is connected through switches, with either
set of collectors. The purpose of the battery is to pick up switches at any time
when it becomes necessary so to do. For example, assume that it is necessary to
pick up the switch S' when the car stands in the position shown. The switch would
then be thrown on to the contact 12, and the switch onto the contact to.
circuit would then be formed from the battery through the contact t², wire g
collector f, a portion of magnet M', collector b, contact to and switch 8 back to the
battery. At other times, when the car is moving in the opposite direction, a similar
circuit would be formed by throwing the switch onto the contact t, and the
switch Sonto the contact t'. If at any time it is desired to charge the battery:
The

page_text: from the line this may be done, for example, by throwing the switch onto the
contact when the line current would pais partly through the battery and partly
through the magnet circuit as heretofore traced. If the car be moving in the opposite
direction a similar result would be secured by throwing the switch onto the
contact t*.
The two sets of line contacts are separated, as shown in the drawing, by a substantial
distance, approximately equal to that which would be bridged by two of the collecting
parts. This secures good insulation, and saves also somewhat in the number of
working contacts.
The system of Figure 2 is very similar to that of Figure 1, except that the line
switches S, S', are connected to an intermediate point in the coils of the magnets,
while two of the working contnets of each set are connected to one terminal of the
magnet coil, and the third working contact to the other terminal. This will be readily
understood from the drawing, as will also the mode of operation.
The system shown in Figure 3 resembles that of Figure 1, except that the working
sections instead of being short points are made of rail sections, and the collectors are
formed of wheels or short brushes. The two systems resemble one another so closely
that the mode of operation of the modification shown in Figure 3 will be understood
without explanation. The parts are lettered in the same way as in Figure 1, and the
car is shown in the corresponding position. For an ordinary twenty-four foot car in
this system the rail sections will be about three feet in length, or a little less, and the
distance between adjacent sets of sections will be approximately equal to ono rail
section,
In Figure 4 there is shown a system where the switching magnets are arranged
so as to have the same function as in Figure 1, but the line contacts are disposed
in sets of two each. With the parts in the position shown, the circuit extends from
the positive conductor A, through the magnet M, collector a, wire e collector hy
through a portion of the magnet M', collector f, switch a', through the motor and
through the wheel G and return conductor B. A portion of the winding of
magnet M is now in series with the motor, and will close the switch S'. In this
modification the line current will however, have to pass through the entire winding
of one of the magnets for a greater portion of the time than in the system of
Figure 1, and I regard the system of Figure 1 as a preferable one. The arrange-
ment of the storage battery and the collectors is substantially the same as has been
already described.
In Figure 5 a similar system is shown, except that the switches S, S' are
connected to an intermediate point in the coils of the magnet, the terminals of the
magnets being connected to the working contacts. In this case the normal line
current will pass through only a fraction of the magnet, while the current actuating
the switch will pass through the entire coil. In this particular the arrangement is the
reverse of that of Figure 4.
In Figure 6 I show how this feature of the invention can be embodied in a
somewhat different system. Here the contacts are arranged in pairs, one opposite or
alongside another, instead of being disposed one after the other along the road hed, as
in Figures 4 and 5. The contacts of each pair are connected to the terminals of the
magnets M, M', and the switches S, S' lead to an intermediate point in the coils.
The arrangement of the collectors is also somewhat modified. A long collector a
which will bridge the distance between two sets of contacts, is connected to the
positive motor terminal and is adapted to engage one set of contacts, as 2¹ and 4'.
Another collector, 64, of similar length, engages the contacts 1', 3', and normally will
be connected through a switch to one or the other of two accessory collectors 61, 62,
which are arranged in line with collector a, but separated therefrom by insulating
breaks. With the parts in the position shown current will pass from the line
conductor A, through the collector as, to the motor so long as the collector a
preserves contact with the contact point 2. When, however, the collector a³ leaves
this contact current then passes from the contact 21 to the collector 6', collector 64,
contact 3, the whole of magnet M and collector a to the motor thus closing the

page_text: advance switch S and putting the magnet in series with the motor circuit. When
the car travels in the opposite direction the switch s will be thrown onto the
contact t, and a similar circuit for actuating the line switches will be formed, as
will be understood.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be perforined, I declare that what I
claim is :-
1. The improvements in or connected with electric traction which consists in tapping
the coils at an intermediate part substantially as and for the purpose set forth.
2. The improvements in or connected with electric traction which consists in
placing the coil (or a part thereof) of an advance switch magnet in series with the
motor substantially as and for the purpose set forth.
3. The combination of an insulated line conductor, a series of working contact
sections normally disconnected from the line conductor, switches for connecting the
line conductor and working sections, electro magnets for operating the switches
having coils which are connected at an intermediate point to the contact sections, of
switches and collectors on the car arranged to establish a circuit through the magnet
of an advanced section, or set of sections, in series with the motor of the car and a
rear section, as set forth.
4. The combination of an insulated supply conductor, a series of collectors on the
car, and a series of working conductor sections divided into sets of three and arranged
along the line of travel, with a space between each set substantially equal to the
distance which can be bridged by two of the collectors, as set forth.
5. The combination of an insulated line conductor, working conductor sections
divided into sets of three, a switching arrangement, for connecting each set of working
sections with the line conductor, and electro magnets for operating the switches whose
coils are so connected at an intermediate point to the working sections that the line
current passes through only a portion of the coil, as set forth.
6. The combination of an insulated supply conductor, a series of working conductor
sections normally disconnected from the supply conductor, switches for connecting
the working sections with the supply conductor, and electro magnets, for operating
the switches, whose coils are connected at an intermediate point, as described, and
collectors on the car so arranged as to establish successively a circuit in series with
the motor through the magnets for actuating an advance switch, and for including
only a portion of the coils in the line circuit for holding the switches closed when
they have been thrown.
7. The combination of a supply conductor, a series of insulated working
conductor sections, switches for connecting the supply conductor and sections,
magnets for operating the switches, collectors establishing a circuit through the
magnets in series between the line and motor for operating the switches, and
a battery on the car connected in multiple with the line circuit through one of
the magnets.
8. The combination of a supply conductor, a series of insulated working conductor
sections, switches for connecting the supply conductor and working sections, collectors
on the car establishing a circuit through the magnets in series between the line and
motor for operating the switches a storage battery on the car, and switches on the
car for connecting the battery so as to place the battery in a shunt circuit, shunting
the line circuit through one of the magnets for a given direction of travel, and
shunting a second magnet for the reverse direction of travel.
11
1007
J. G. LORRAIN, M.I. Mech. E., M.I.E.E.,
Norfolk House, Victoria Embankment, London, W.C.,
Chartered Patent Agent.