Improvements in Means to be employed in Electric Traction.
Year: 1899

page_text: Improvements in Means to be employed in Electric Traction.
I, MARIE JOSEPH BARREAU, of 12, Rue Ernest, Puteaux, in the Republic of France,
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention relates to electric traction and it has for its object to render
electric motors better adapted for practical use for this purpose than hitherto.
In motors of this class as hitherto employed for purposes of traction, the amount
of effective work varies within wide limits. A motor for example constructed to
give a normal difference of potential of 80 volts. at the terminals and whose useful
effect is tolerably good while that standard is maintained does not work efficiently
when such norinal standard is departed from. While the vehicle travels on a level
road and at a slow speed, for instance the motor will expend far more energy than
is necessary for enabling it to operate at that rate of speed.
According to my invention I divide the windings of the induction coils into
sections and connect these sections into sets or groups and I similarly arrange and
connect the cells of the source of electricity the invention being based upon the fact
which I have demonstrated that in order to secure the maximum of effective work
notwithstanding variations of speed it is only necessary to maintain the inducing
magnetic flux or current at a constant value. So long as this condition is fulfilled,
the speed will be proportionate to the voltage of the source of electricity. Supposing
a motor intended to operate at three different rates of speed has to be dealt with its
induction-coils will be divided into four sections and the battery by which it is fed
will also be divided into four parts. To simplify the illustration I will assume that
the four induction-coil sections have the same resistance and that the four parts of
the battery are all alike, and I will further suppose that the voltage of the cells
of the battery will remain constant, which will be correct if the battery be sufficiently
powerful.
Let e express the constant electro-motive force of each of the four parts of the
battery; r, the resistance of each of the four induction-coil sections, and n the number
of inducing spirals, or convolutions, in each section.
Then (1) if the four parts of the battery be connected in series the electro motive
force at the binding screws will be 4 e; if the same mode of connection be adopted with
regard to the induction-coil sections, their resistance will be 4 r; the current passing
through them will have an intensity of

page_text: being a constant co-efficient for the motor in question.
(2) If the parts of the battery, and also, consequently, the induction-coil sections,
be connected in series parallel the electro-motive force at the binding screws will be 5
2 e, while the resistance in the induction-coils will be
(3) If the four parts of the battery, and likewise the four induction-coil sections,
=e; the resist-
be coupled in parallel the resulting electro-motive force will be
r"
ance = 3; and the intensity of current
1
4 i.
11
A1
A current-inverter arranged either in the inducing circuit or in the induced circuit,
will, whilst altering the direction of the current, produce, in the rearward direction,
three speeds equal to the three different speeds just defined as applying to the
forward motion.
My invention is applicable to compound-motors by dividing the two inducing
circuits at the same time and connecting them into groups in the manner herein-
before described.
It is quite immaterial what may be the type or construction of the motor for
The
example it may be bipolar, or multi-polar, with multiple induced armatures.
number of sections which I provide in the winding of the induction-coil, and the
number of parts into which I divide the battery, may vary according to the number
of different groups or connections I wish to obtain. My invention may be applied
not only to traction, but to navigation as well as to the transmission of motive-
power.
I have hereinbefore indicated the conditions which are most favorable to the
attainment of the desired result; but in the event of the potential of the source
of electricity being constant, the division of the induction-coils into sections would
result in still further varying the speed by causing the flux of the current to vary.
The final result however would not be quite as good as in the case first indicated.
The different connections between the cells of the source of electricity and the
sections of the induction-coils may be effected by means of apparatus consisting
of a cylinder of insulating material, secured to a shaft which revolves in bearings
secured to the frame of the apparatus. Upon this cylinder are arranged a number

page_text: of metal keys connected with each other so as to be capable of forming the
connections at the different phases. In front of the keys there are arranged brushes
connected to the several component elements of the motor and to the cells of the
battery, by means of connections which secure the supports or feet of the brushes
to a plate of insulating material.
To one of the extremities of the shaft a removeable crank can be connected (by
a groove and feather or otherwise) which serves to throw the mechanism into gear
the said crank supporting an index-hand, which points to anyone of a number of
guidemarks on the end or top plate or other convenient part of the apparatus. This
plate and the crank are of such shape that when the crank is in position water cannot
gain access to the interior of the apparatus through the aperture in the end or top
plate. To the opposite end of the shaft there is secured a star wheel in the notches
of which. a roller engages, which roller is pressed against the said star wheel by
a spring and is supported by a short connecting rod, or link. The recesses in the
star wheel correspond to the positions of the keys opposite the brushes, and the
configuration of the notches, or slots, is calculated to enable connections to be made
and broken instantaneously, by means of this device, which it is necessary to do to
avoid sparking. The apparatus is enclosed in an outer casing.
The number of keys and brushes depends upon the number of different connections
to be provided for.
Dated this 30th day of June 1899.
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.
Improvements in Means to be employed in Electric Traction.
I, MARIE JOSEPH BARREAU, of 12, Rue Ernest, Puteaux, in the Republic of France,
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 electric traction and it has for its object to render electric
motors better adapted for practical use for this purpose than hitherto.
In motors of this class, as hitherto employed for purposes of traction, the amount
of effective work varies within wide limits. A motor, for example, constructed to give
a normal difference of potential of 80 volts. at the terminals and whose useful effect
is tolerably good while that standard is maintained does not work efficiently when
such normal standard is departed from. While the vehicle travels on a level road.
and at a slow speed, for instance, the motor will expend far more energy than is
necessary for enabling it to operate at that rate of speed.
According to my invention I divide the windings of the induction coils into
sections and connect these sections into sets or groups and I similarly arrange and
connect the cells of the source of electricity; the invention being based upon the
fact which I have demonstrated that in order to secure the maximum of effective
work notwithstanding variations of speed, it is only necessary to maintain the indu-
cing magnetic flux or current at a constant value. So long as this condition is
fulfilled, the speed will be proportionate to the voltage of the source of electricity.
The invention will be best understood by reference to the accompanying drawings
in which
Figures 1, 2 and 3 are. diagrams illustrating the method of connecting the sections

page_text: of the induction-coils and the cells of the source of electricity as applied to a "shunt"
motor, into sets or groups.
Figure 4 summarizes the three first-mentioned diagrams, and it illustrates the
connections to be made both for stoppages and for backward motion.
Figures 5, 6, 7 and 8 are corresponding views of arrangements or connections to
be adopted in the case of a series "motor.
66
Figures 9, 10 and 11 represents what I term my " combiner" being a device for
forming the various groups as required, Figure 9 being an axial longitudinal section
thereof, Figure 10 a section on the line A-B, Figure 9 and Figure 11, a section on
the line C-D, Figure 9.
The simultaneous and parallel grouping of the sections of the induction-coils and
the cells of the battery, respectively, suffices to maintain a constant flux or motion of
current and consequently to impart to the vehicle a speed proportionate to the
difference of potential at the terminals of the motor, whether such motor be a shunt
or a series motor. Supposing a motor intended to operate at three different rates of
speed has to be dealt with, its induction coils will be divided into four sections and
the battery by which it is fed will also be divided into four parts. To simplify the
illustration I will assume that the four induction-coil sections have the same resist-
ance and that the four parts of the battery are all alike; and I will further suppose
that the voltage of the cells of the battery will remain constant, which will be correct
if the battery be sufficiently powerful.
Let e express the constant electro-motive force of each of the four parts of the
battery; r, the resistance of each of the four induction-coil sections, and n, the
number of inducing spirals, or convolutions, in each section.
Then (1) if the four parts of the battery be connected in series, the electro motive
force at the binding screws will be 4e; if the same mode of connection be adopted
with regard to the induction-coil sections, their resistance will be 4r; the current
passing through them will have an intensity of

page_text: A current-inverter arranged either in the inducing circuit or in the induced circuit,
will, whilst altering the direction of the current, produce, in the rearward direction,
three speeds equal to the three different speeds, just defined as applying to the
forward motion.
Figures 4 and 8 are diagrams of the connections producing the three speeds
hereinbefore mentioned and also the connection required for the stoppage, during
which the accumulators are charged and that which will bring about one speed in the
rearward direction. In these figures the four parts of the battery are shewn at a,
the four sections of the induction windings, at b and the induced armature, at c.
All
the positive poles are designated by odd numbers, from 1 to 17, and all the negative
poles by even numbers, from 2 to 18.
The connections represented at V° correspond to the stoppage of the vehicle; it
will be seen that all connections, except those of the battery, are broken off. By
conducting the current from the source of electricity to the contacts or poles at 1
and 8, the storage-cells may be charged.
The connections represented at V₁ correspond to the full speed (Figure 1).
Similarly the position V2 corresponds to Figure 2, and the position V3 to Figure 3.
And the position V* corresponds to the position V3 and to Figure 3, except that here
the poles 17 and 18 of the armature have been exchanged and consequently the
current in this armature, takes an opposite direction in each case.
My invention is applicable to compound motors by dividing the two inducing
circuits at the same time and connecting them into groups in the manner herein-
before described.
It is quite immaterial what may be the type or construction of the motor for
example it may be bipolar, or multi-polar, with multiple induced armatures. The
number of sections which I provide in the winding of the induction-coil, and the
number of parts into which I divide the battery, may vary according to the number
of different groups or connections I wish to obtain. My invention may be applied
not only to traction, but to navigation as well as to the transmission of motive-power.
I have hereinbefore indicated the conditions which are most favorable to the
attainment of the desired result; but in the event of the potential of the source of
electricity being constant, the division of the induction-coils into sections would
result in still further varying the speed by causing the flux of the current to vary.
The final result however would not be quite as good as in the case first indicated.
The different connections between the cells of the source of electricity and the
sections of the induction-coils may be effected by means of apparatus represented in
Figures 9, 10 and 11.
This apparatus consists of a cylinder d of insulating material, secured to a shaft e
which revolves in bearings f g secured to the frame of the apparatus. Upon this
cylinder are arranged a number of metal keys h connected with each other so as to be
capable of forming the connections at the different phases illustrated by the
diagrams (Figure 4 and 8). In front of the keys there are arranged brushes i
connected to the several component elements of the motor and to the cells of the
battery, by means of connections which secure the supports or feet of the brushes to
a plate of insulating material k.
To one of the extremities of the shaft e a removeable crank m can be connected (by
a groove and feather or otherwise) which serves to throw the mechanism into gear
the said crank m supporting an index-hand, which points to anyone of a number of
guidemarks on the end or top plate or other convenient part of the apparatus. This
plate and the crank are of the shape shewn so that when the crank is in position

page_text: water cannot gain access to the interior of the apparatus through the aperture in the
end or top plate. To the opposite end of the shaft there is secured a star wheel n
in the notches of which a roller o engages which roller is pressed against the said star
wheel by a spring p and is supported by a short connecting rod, or link, q. The
recesses in the star wheel correspond to the positions of the keys opposite the
brushes, and the configuration of the notches, or slots, is calculated to enable connec-
tions to be made and broken instantaneously, by means of this device, which it is
necessary to do to avoid sparking. The apparatus is enclosed in an outer casing.
The number of keys and brushes depends upon the number of different connections
to be provided for.
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 combination with electric motors induction-coils composed of a number of
sections and means for grouping or connecting them in various ways substantially as
herein before described.
2. In combination with electric motors a device adapted to produce varying speeds
and to maintain, practically constant, the amount of effective work of the inotor
during the various stages of its operation, the said device consisting in a division of
the induction-coil windings into sections, and of means for coupling these sections in
a parallel and simultaneous manner with the cells of the source of electricity, accord-
ing to the speeds to be obtained, substantially as hereinabove described and
illustrated in Figures 1 to 8 of the accompanying drawings.
Dated this 21st day of March 1000
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.