An Improved Controlling Device for Electric Motor Vehicles and the like.
Year: 1898

page_text: Date of Application, 6th Apr., 1898
Complete Specification Left, 23rd Nov., 1898-Accepted, 28th Jan., 1899
Date of Application, on Apr. 100
Complete Specification Left, 23rd Nov., 1898-Accepted, 28th Jan., 1899
An Improved Controlling Device for Electric Motor Vehicles
and the like.
Communicated to me by HENRY LEITNER, of Hotel Campbell, Avenue Friedland,
Paris.
I, GEORGE HENRY RAYNER, of 37, Chancery Lane, London, Patent Agent, do
hereby declare the nature of this invention to be as follows:—
This invention relates to improvements in controlling mechanism for electric
motor vehicles, and has for its object to provide an improved means whereby the
power employed in braking the vehicle when descending a gradient is utilised in
storing the electrical energy for future use.
In carrying out this invention the current from the accumulators is carried to
a controlling device which consists of a pivoted arm or lever arranged with a
number of spring contact bridges. These bridges are adapted to span across
certain contacting pins or studs fitted to an insulating board. These pins are
preferably arranged in radial lines so that as the arin is pulled over, those in lines
are brought into contact.
The accumulators are preferably arranged in two sets one containing a greater
number of cells than the other, and the conductors on the larger battery of
accumulators are so connected up that the main portion of the current can be
employed to excite the field magnet of the electro motor which drives the vehicle.
A portion of the current however passes through the armature and a contrary
current can pass to the second battery of accumulators.
When the armature is at rest the current at a smaller pressure passes through
it, and therefore develops no counter-electro motor force of its own, and at the
same time a greater current will pass through the field magnets giving a greater
starting effort or torque to the driving shaft of the vehicle.
When the speed of the vehicle rises beyond a certain limit, the lever is thrown
over to another portion of the controlling device which reduces the magnetic field
of the field magnet to slightly under saturation and an increased current passes
through the armature due to a higher pressure which results from bringing
more cells into circuit.
To still further increase the speed of the vehicle the lever is pushed further for-
ward bringing into action a resistance coil in the field thereby weakening it,
increasing the current in the armature giving a greater rotation of the latter.
In the latter case the efficiency of the motor is somewhat under the average, more
current being expended than when the motor is working normally.
When the speed of the motor increases when descending a gradient, the con-
nections are so arranged that the back electro-motive pressure of the armature

page_text: sets up a current in the opposite direction which feeds into the accumulators and
the energy so stored may be used at some future time in propelling the vehicle.
Dated this 6th day of April 1898.
GEO. H. RAYNER,
37, Chancery Lane, London, Agent for the Applicant.
DEVICE Por Mectric motor vehicles
and the like
Communicated to me by HENRY LEITNER, of Hotel Campbell, Avenue Friedland,
Paris.
I, GEORGE HENRY RAYNER, of 37, Chancery Lane,, London, Patent Agent, 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:-
12
This invention relates to improvements in the means for controlling electric
motor vehiclés having for object to obtain great torque at starting the vehicle or
whenever great resistance is to be overcome, to absorb the energy of the vehicle in
descending a gradient in the accumulators and then to utilise the force applied in
checking the speed as stored energy available again for propulsion.
For this purpose the motor and battery are connected in a peculiar manner.
Two batteries are employed, one considerably larger than the other, the smaller
battery being arranged to supply current to the field magnet so as to keep the
magnet always nearly saturated, except under special circumstances hereinafter
described. The main battery supplies the armature, and is also connected to the
smaller battery through which the main current passes in a direction contrary to
its E. M. F thus charging the smaller battery while it is at the same time dis-
charging through the field magnet coils. The circuit of the main battery being
through both the smaller battery and the field magnet coils which are in parallel,
part of the main current necessarily passes through the field magnets, although
they are independently excited by the small battery. The apparatus is so arranged
that the motor acts as a dynamo when the vehicle goes downhill, or when its speed
increases beyond that determined by the controller. The motor thus not only
acts automatically as a brake to prevent increase of speed beyond that desired, but
also sends the current back into the main battery and charges it. Thus the
energy of the car in descending a gradient is not wasted, but is stored electrically
in the accumulator.
As there is a double path for the current from the main battery, should the
exciter become exhausted or should internal contact be broken in any way, the
main current would pass directly through the field magnet coils, the motor in this
case acting temporarily as a series motor. Thus the motor can have its field
magnets excited in three ways so as to act as a shunt motor; a series motor, or
an independently excited motor.
In order that the invention may be more readily understood, reference is had
to the accompanying drawings, which show two slightly different methods of carry-
ing out the invention. The details of construction may however be considerably
varied without departing from the fundamental principle of the invention.
Fig. 1 is a diagrammatic, view of the general arrangement. Fig. 2 is a side view

page_text: of the controlling apparatus used in connection therewith. Fig. 3 is a plan of
the apparatus, Fig. 4 is a side view of one part of it, and Fig. 5 shows diagram-
matically the electrical contacts and their connections. Figs. 6, 7 and 8 are
diagrammatic views of a modified arrangement in three different conditions,
Fig. 9 showing diagrammatically the controller for the modified arrangement,
and Figs. 10 and 11 are respectively a side elevation partly in section and a front
elevation of the modified controlling apparatus.
Referring first to Fig. 1 A is the armature of the motor, and A' its field magnet.
The line B connects the one brush of the armature to one pole of the main
battery C, which is divided into two sections that can be connected either in series
or in parallel by the controlling device as will be hereinafter described. The
other line B' leads first to the small battery D, which may be of two cells only,
and B¹ continues to the other pole of the main battery passing on its way through
the controller as will be described. The connections E of the field magnet lead
directly to the small battery ]) SO that the field magnet is excited
directly by this battery, which may be termed the exciter. The exciter is so
connected to the main battery that the main current passes through the exciter
in opposition to its own electromotive force, the positive pole of the exciter being
connected to the positive pole of the battery. The exciter, when two cells are
employed, supplies a current at a pressure of about 4 volts, considerably larger
however, than this at starting, so that the field magnet is excited up to saturation.
The more the energy required for starting the higher is the voltage of the exciter
because the current supplied to the armature has to pass through the exciter as a
charging current. The cells of the exciter do not require to have great capacity,
but must be of a kind which will allow a large current to pass through them,
that is, into them and out of them, and which will be able to stand great variations
in the current. The form of cell that I use has the additional advantage of
polarizing with very high charging currents and the exciter thus automatically
chokes off excessive current from the armature and its own voltage is often in
consequence over three volts per cell under the circumstances referred to.
The action of the arrangement is as follows:-On the current being turned
on to start the motor the full current passes through the exciter and causes a
sudden generation of gas polarizing it and resisting the passage of the current
for a short time. The full charge of current being thus prevented from passing
instantly through the armature of the motor, undue strain in starting is avoided.
The current rapidly attains its normal flow and the vehicle increases its motion
until it attains the speed desired. As this speed depends upon the EM F of the
current applied to the armature, in starting, the two parts of the main battery B
are placed in parallel, so that for a battery of forty cells, the starting E M F
would be about 40 volts.
When a higher speed is desired, the battery is placed with its two parts in
series, giving a current at 80 volts and doubling the speed of the motor. As will
be seen the current from the main battery has a double path on its way to the
motor, the one path through the exciter and the other through the field magnet.
The resistance to the current is thus reduced as the exciter and the field magnet
are in parallel with respect to the main circuit. The E M F of the exciter must
be deducted from the EM F of the main circuit, and the current from the main
battery is partly used in keeping the exciter fully charged.
On the motor increasing in speed beyond the limit set by the controller, owing
to the vehicle running downhill or from any other cause, a back electromotive
force is set up in the motor, and a current passes through the main circuit in the
opposite direction. The current is aided by the exciter, which thus discharges
not only through the field but also back into the main battery. As this condition
however lasts only for a short time, there is no danger of the exciter becoming
completely discharged. The reverse current does not interfere with the field as
the EM F of the exciter keeps up the difference of potential at the terminals of
the field coil. The exciter thus continues to supply the current to the field

page_text: which is not reversed. The exciter serves as an electric valve to determine the
path of the reverse current.
In connection with this system of motor and batteries, I employ a controller of
a type which allows the speed of the motor to be determined and which also
permits of reversal, so as to drive the vehicle backwards.
Figs. 2 to 5 show such a type of controller the mechanical details of which may
be varied.
This controller acts mainly by putting the two parts of the main battery into
series or parallel, but the same effect might be produced by independent armature
windings which may be placed either in series or parallel.
The controller consists of the case, F of insulating material provided with the
rubbing contacts G. The controller is in the form of a circular section and the
contacts are arranged in four circular rows, and in five radial lines. A controlling
lever His pivoted at h to the lower end of the casing, this lever carrying the two
sets of brushes h' on each side. Each brush when the lever is in operative position
bridges over at each side the two adjacent contacts in the same radial line. The
contacts are thus divided into two sets, an inner and outer set one pair of
brushes connecting the outer and the other the inner set as shown in Fig. 2.
The curved rim of the controller has a slot J through which the lever projects
presenting a handle outside. At one side of the slot are notches which serve to
retain the lever in any position to which it is turned. The controller shown
presents 6 positions in one of which indicated by the dotted line in Fig. 4 no
circuits are formed, the motor being then at rest.
To retain the lever in any one of the 6 positions there is a spring catch ² pro-
jecting into the notch, but the spring yields to allow the lever to be pushed by
slight exertion to a fresh position.
On one side of the dotted line there are four sets of radial contacts which are
used for driving the vehicle forward at varying speeds. A single radial set on the
left side of the dotted line is employed for driving the vehicle backwards.
In Fig. 5 the connections of the contacts are shown diagrammatically, the black
circles representing the contacts those which are connected together being linked
by black lines. Fig. 5 shows the contacts on both sides of the controller, those
on the left being for the one side as shown in Fig. 4 and those on the right for
the other side, which is generally similar.
On both sides contact is made simultaneously so that when connection is made
between any pair on the one side, connection is simultaneously made between the
corresponding pair on the other side.
The main battery is divided into two parts, the poles of which are marked
respectively C+, C₁-, C₁+, and C-. On connecting C₁+ and C₁- the two
parts of the battery are put in series, and a high E M F is obtained. On con-
necting the positive poles together and the negative poles together, the two parts
are put in parallel, and the electromotive force is reduced to half. The upper
pair of contacts only connect with the battery and consequently with the armature
of the motor, while the lower pair are connected to the exciter and to the field
magnet. Those marked D + and D- belong respectively to the positive and
negative poles of the exciter and the contacts marked A' are connected with the
field magnet A¹. The reference letters of the contacts belonging to the battery
correspond to those marked upon the poles of the battery. Resistances L and L
are placed in the exciter circuit, so that when the lever is moved over to connect
the contacts to the right hand side of one or both of these resistances the current
supplied to the field magnet is reduced.
On turning the lever from the zero position to the right to start the motor
forward, connection is made on the left hand side between contacts marked C-
and Cand between D and A¹. On the right hand side the connections are
between C and C+ and between D+ and A. This arrangement puts the two
parts of the battery into parallel and supplies the field magnet with current from
the exciter.

page_text: On moving the lever to the second step, change is made only in connection with
the main battery, the connections of the two upper pairs of contacts being as
follows:- C₁+ and C¹ on both sides, thus putting the two parts of the battery
in series. The next step does not alter the arrangement of the contacts, but brings
into the circuit of the exciter and field magnet the resistance L. This reduces
the strength of the field and enables a higher speed to be attained by the motor
when the vehicle is running on level ground and great torque is not required.
On turning the lever still further, the second resistance L is also brought into
this circuit still further weakening the field. The stages thus arrived at. are
as follows;-
1. The two parts of the battery are in parallel and
a
current at an EM F of say
40 volts is supplied to the armature of the motor; at the same time the field
magnet is fully excited.
2. The two parts of the battery are placed in series and current at say 80 volts
is supplied to the armature doubling the speed of the motor. The field magnet
remains fully excited.
3. The grouping of (2) is not altered but the strength of the field is reduced,
allowing greater speed of the motor to be obtained when the resistance to the
motion of the vehicle is not great.
4. A further resistance is brought into the field and exciter circuit.
The variations of speed obtained by weakening the field can of course be also
introduced between speeds 1 and 2.
When the lever is turned from the zero position to the left so as to drive the
motor in the reverse direction, the connections are as follows:-
On the left hand side from C-to C-and from D + to A¹. On the right hand
side they are from C+ to C¹ + and from D-to A¹. The arrangement of the
armature contacts is thus the same as in the first stage for forward driving, but
the current through the field magnets is reversed. The motor is then driven in
the reverse direction.
In the arrangement illustrated in the remaining figures the main battery is, not
divided into two parts. Referring first to Figs. 6, 7 and 8, C2 is the main battery
having a considerable number of cells and D¹ is a small battery which serves as
an exciter, but is also utilised in certain cases to assist the main battery C². The
connections are altered by means of the controller which is illustrated in Figs. 9,
10 and 11 so that they can be grouped for forward driving into the conditions
shown in the general diagrammatic views. In the first stage the connections M
and M¹ pass respectively from the armature A to the positive pole of the main
battery C and to the positive pole of the small battery D¹. At the same time
the connections N and N¹ belonging to the field magnets pass respectively to the
positive and the negative poles of the small battery. A further connection 0
connects the negative poles of the large and smaller battery together. The main
current from the large battery 02 thus passes through D¹ against its .E M F and
goes thence to the armature and back to the positive pole of the battery C2... The
EMF of the main battery is thus reduced by that of the small one, and a current
At the same time, the
at a relatively low E M F is supplied to the armature.
battern D supplies the field magnet circuit independently through the
connections N and N¹.
In the second condition shown in Fig. 7 the small battery D¹ serves merely as
an exciter for the field magnets, and is quite disconnected from the main battery.
This forms an independent circuit including only the armature. In this. case the
full EM F of the large battery is utilised and a higher speed of, the motor is
consequently obtained.
In the third condition Fig. 8 the two batteries are put in series so that the
combined EM F of both is obtained in supplying the current to the armature.
The field magnet is in this case in a shunt circuit off the small battery D¹, but
is still kept fully excited. The connection O¹ in this case passes from the negative
pole of the main battery to the positive pole of the small battery, so as to complete

page_text: the circuit. In this latter arrangement the motor attains an increased speed
owing to the higher tension of the current passing through the armature.
Fig. 9 shows the grouping and connections of tho controller used with this
modified arrangement. The apparatus is somewhat similar to that already
described, but it differs in detail, as the purpose is not to put the two parts of the
main battery in series or parallel, but to put the two batteries which serve
instead of them in opposition, in independence or in series. The radial dotted
lines marked by numbering indicate the different positions of the lever as it is
turned to increase or decrease the speed, or to reverse the motor. The lever is
normally at the zero line marked when the vehicle is at rest. The sets of
contact bars or pieces marked a to j are concentric. The lever connects pairs
of these namely:a b, c d e f g h i j.
When the lever is at the zero line O no circuits are made, in the position I,
the connections are made as in Fig. 6. The first pair of brushes on the lever
(which is hereinafter described with reference to Figs. 10 and 11), I connect the
two bars ab completing a portion of the circuit which is shown by the reference
letter N Fig. 6, the bar a being connected to the field magnet and b to the
negative pole of the small battery. The second pair of brushes connects the
second pair of contacts c d, of which c belongs to the second pole of the field magnet
and d to the positive pole of the small battery. The field magnet circuit is thus
completed. This connection corresponds to the letter N in Fig. 6. The third
pair of brushes belong to the armature circuit connecting the bars e f, of which e
belongs to one pole of the armature and f to the positive pole of the small
battery (Fig. 6). The fourth connection unites g h, g belonging to the
negative pole of the small battery and h to the negative pole of the large battery,
corresponding to the connection O. The bars ij form connection between the
other pole of the armature and the positive pole of the large battery (M Fig. 6).
The second position leaves the connections a bcd, and ij the
same, but the bars gh are missed, thus breaking the connection
between the large and small batteries. ef is altered SO that the
connection of the armature is changed from the positive pole of the small
battery to the negative pole of the large battery, corresponding to M' in Fig. 7.
The third position still leaves the connections a b, c d'i j, but again alters e f
which now connects one pole of the armature to the negative pole of the small
battery as shown at M¹ Fig. 8. h unites the positive pole of the small battery
with the negative pole of the large as at 01 in the same figure.
The fourth, fifth and sixth positions introduce successively the resistances P P¹
and P2 into the field magnet circuit, so that this is successively weakened, enabling
high speed to be obtained when the resistance to the car is not great.
The reversing stage marked 7 in Fig. 9 gives the following connections which
can be traced on the figure. a b connects the field magnet with the negative pole
of the small battery and c d connects it with the positive pole of the same.
ef forms the connection between the armature and the positive pole of the small
battery, h between the negative pole of the small battery and the negative pole
of the large battery, while i j completes the armature circuit by a connection
between its other pole and the positive pole of the large battery. The arrange-
ment is thus the same as in the first position except that the current in the field
is reversed.
Referring now to Figs. 10 and 11 which show the construction of the controller
in detail Q is the base plate carrying the insulating piece q on which the contact
bars are carried. The levers carry the five bridges or pairs of brushes T which as
shown in Fig. 10 connect the bars in pairs a b, c d, e f, gh, and i j.
At the upper part of the lever is an arrangement for preventing sparking when
the lever is turned from one position to another. The lever is provided with the
handle U which is pivoted to it and limited in its motion at each side by the
double stop on the lever. The handle is provided with the rubbing contact
pieces one at each side, and the forked end a of the lever is also provided with

page_text: the contact strips s. When the handle U is in its normal position in line with
the lever these contacts bear against each other and form part of the circuit both
the handle and lever being provided with the terminals u² and s². When how-
ever the handle is turned to one side as shown in Fig. 11, so that it abuts against
the stop u, the circuit is broken and the lever can then be pulled over into a new
position without danger of sparking from the contact bars R. When the new
position is attained, the handle is put back into its normal position, and the
circuits are completed. The contact strips at one side are placed in the field
magnet circuit, and those at the other are in the armature circuit so that they
are both completed simultaneously or broken simultaneously when the handle
is moved. The handle U is first pulled over in the direction in which the lever
is to be moved, so that after the handle U meets the stop u a further pull moves the
lever into the desired position.
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 apparatus for controlling electric motor vehicles the combination of a
motor, a large and a small battery supplying the current to the armature and field
magnet of the motor and connections forming a double path for the main current,
the path passing through the small battery, in a direction contrary to its E M F,
and through the field magnet coils on its way to the armature, substantially as and
for the purposes specified.
(2) In means for controlling electric motor vehicles, the following arrange-
ment of elements-a motor, a large and a small battery supplying current
to the motor, means for controlling the E M F of the said current, and connec-
tions between the motor and batteries arranged so that the current from the main
battery will pass through the exciter in oppositon to the E M F of the latter,
substantially as described.
(3) In combination with the parts mentioned in the preceding claims a con-
trolling apparatus consisting of an insulating base carrying contact pieces
connections between these contact pieces and the batteries and motor, a lever
carrying bridging brushes to connect the said contacts so that the current supplied
to the motor can be varied and resistances can be introduced in the circuit of
the field magnet, substantially as described and for the purposes specified.
Dated this 23rd day of November 1898.
GEO. H. RAYNER,
37, Chancery Lane, London, Agent for the Applicant.