Improvements in or in connection with Alternating Current Electric Motors.
Year: 1895

page_text: .Dite claimed for Patent under Sect. 103 of Act, 1
⚫ being date of 'first foreign Application (in (3rd July, 1894
Switzerland),
Improvements in or in connection with Alternating Current
Electric Motors.
We, CHARLES EUGEN LANCELOT BROWN, WALTER BOVERI, and FRITZ
FUNK, trading under the style of Brown, Boveri & Co., at Baden, Switzerland,
Engineers, do hereby declare the nature of this invention to be as follows:-
This invention relates to uni-phase alternate current motors and is designed to
enable such motors to be started without great consumption of current, but with
great power, and with but slight reaction upon the network of conductors.
This result is attained by combining with the motor electrolytic or storage cells
and switching or connecting devices in such a manner as to enable electrolytic cells
to be included in a portion of the inducing winding for the purpose of producing a
rotary field, and also to enable such cells to be included also in the current circuits
of the induced winding. These cells by reason of their capacity, serve to prevent
too great a fall of potential in the network of conductors on starting the motor.
When the motor has attained a certain speed of rotation the cells are switched
off from the inducing coils; but being, however, if desired, left partially in
connection with the induced coils, in case it be desired to let the motor work at a.
speed below the ordinary or normal speed.
The rotary field for starting may be produced by switching the inducing coils as
shown in the diagrams Fig. 1 or Fig. 2. In the diagram Fig. 1, the inducing
coils A A' are coupled up in series, and are directly connected to the conductors L, Li
and the apparatus for producing the shifting of phase is arranged in parallel to a
part thereof.
This apparatus consists of a number of electrolytic cells K,
collectively of very great capacity.
The currents in the two halves of the coils are by this arrangement altered in
phase relatively to each other, whereby there is produced a rotary field, as in the
case of a so-called multiphase motor.
When the desired speed has been attained, the cells K are switched off.
In the diagram Fig. 2, the inducing winding is coupled up in two halves A, A¹
arranged in parallel. One half A is directly connected to the conductors L, L',
whilst the current which flows through the other hall A¹ has also to pass through
the electrolytic cells K. The consequence of this is again a shifting of the phase
of the currents with a resulting rotary field. When the desired speed has been
reached, the half A' is cut out or switched off, and may if desired be coupled up in
series with A.
The arrangement and connection or switching of the windings on the inducer are
illustrated in Figs. 3 and 4 as applied to a ring, although a drum could be employed
equally well. In these figures the same letters of reference indicate the same parts

page_text: as in the preceding figures. Usually the inducer is made the fixed or stationary
part of the motor, but obviously it might if desired be made the rotating part.
The induced part is provided with a winding which may be constructed as a ring
or as a drum, and as a uni-phase or a multiphase current winding, and with any
desired connection. At one or more places, branches are taken from the winding
to corresponding rubbing contact rings. It is preferable to employ three branches.
These rubbing contact rings are connected by means of brushes with groups of
electrolytic cells, the operating number of which can for the purpose of regulation
be varied. On starting, the number of cells is at its maximum, and is reduced as
the speed increases until the full speed is reached, when all the cells are cut out.
Fig. 5 illustrates an induced part with ring winding and with three rubbing
contact rings C1, C2, C3 which are connected by means of the brushes B¹ B² B³ with
the cells K K K³. By means of variable contacts k₁, k³, k³, a greater or a less
number of cells can be included in the current circuit. Also by moving the plates
of the cells nearer to or away from one another, a regulating action can be
produced. When the induced part is made the stationary part, the rubbing contact
rings and the brushes are dispensed with.
Dated this 22nd day of January 1895
F. WISE HOWORTH,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicants.
COMPLETE SPECIFICATION.
Improvements in or in connection with Alternating Current
I.
Electric Motors..
We, CHARLES EUGEN LANCELOT BROWN, WALTER BOVERI, and FRITZ
FUNK, trading under the style of Brown, Boveri & Co., of Baden, Switzerland,
Engineers, 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 alternate current motors and is designed to enable
such motors to be started without great consumption of current, but with great
power, and with but slight reaction upon the net-work of conductors connected
therewith.
In the case of single phase motors this result is attained by combining with the
motor, electrolytic or storage cells and switching or connecting devices in such a
manner as to enable-the electrolytic or storage cells to be included in a portion of
the inducing winding for the purpose of producing a rotary field, and also to enable
such cells to be included in the current circuits of the induced winding. These
cells, on account of their capacity, serve also to prevent too great a fall of potential
in the net-work of conductors on starting the motor.
When the motor has attained a certain speed of rotation, the cells are switched
off from the inducing coils, but they may, if desired, be left partially in connection
with the induced coils, if it be desired to let the motor work at a speed below the
ordinary or normal speed.
The rotary field for starting may be produced by switching or connecting the
inducing coils as shown in either of the diagrams Fig. 1 or Fig. 2 of the drawings
filed with our Provisional Specification.
In the arrangement represented by the diagram Fig. 1 the inducing coils A, A'
are coupled up in series, and are directly connected to the conductors L, L', and
the apparatus for producing the alteration of phase is arranged in parallel to a part
of the inducing winding. This apparatus consists of a number of electrolytic or
storage cells K, collectively of very great capacity.
The currents in the two halves of the winding are by this arrangement altered in

page_text: phase relatively to each other, whereby there is produced a rotary field, as in the
case of a so-called polyphase motor. When the desired speed has been attained,
the cells K are switched off.
In the arrangement represented by the diagram Fig. 2 the inducing winding is
coupled up in two halves A, A' arranged in parallel. One half A is directly
connected to the conductors L, L', whilst the current that flows through the other
half A has also to pass through the cells K. The consequence of this is again an
alteration of the phase of the currents with a resulting rotary field.
desired speed has been reached, the half A' is cut out or switched off, and may if
desired be coupled up in series with A, but the cells K are cut entirely out
of circuit.
When the
The arrangement and connection or switching of the windings on the inducer are
illustrated in Figs. 3 and 4, as applied to a ring, although a drum could be employed
equally well. In these figures the same letters of reference indicate the same
parts as in the preceding figures. Usually the inducer is made the fixed or
stationary part of the motor, but obviously it might if desired be made the rotating
part.
The induced part of the motor is provided with a winding which may be
constructed as a ring or as a drum, and as a single phase or as a poly-phase current
winding, and with any desired connection. At one or more places, branches are
taken from the winding to corresponding rubbing contact rings. It is preferable
to employ three branches. These rubbing contact rings are connected by means
of brushes with groups of electrolytic cells, the operating number of which can,
for the purpose of regulation be varied. On starting, the number of cells is at
its maximum, and is reduced as the speed increases, until the full speed is
reached, when all the cells are cut out. In the case of single phase motors, the
electrolytic cells are introduced both in the inducing and induced windings, or
in the induced without the inducing, but in the case of poly-phase motors they
are only introduced in the induced winding.
Fig. 5 illustrates an induced part with ring winding and with three rubbing
contact rings C1, C2, C3, which are connected by means of brushes B1, B2, B³
with three groups of cells K', K, K³. By means of variable contacts k¹, k², k³,
a greater or a less number of cells can, at will, be included in the current
circuit. Also by moving the plates of the cells nearer to or away from one
another, a regulating action can be effected. When the induced part is made
the stationary part, the rubbing contact rings and the brushes are dispensed
with.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
:-
1. For the purpose of starting an alternating current motor with great power but
with slight reaction upon the net-work of conductors connected therewith, the use
of electrolytic or storage cells arranged so as to be capable of being included in a
part of the inducing and induced windings, or in the induced winding alone of
a single phase motor, or in the induced winding only of a polyphase motor,
substantially as herein described.
2. The several arrangements of electrolytic or storage cells in connection with
alternating-current motors, shown diagrammatically in and described with reference
to Figs. 1 to 5 inclusive of the drawings herein referred to.
F. WISE HOWORTH,
.46, Lincoln's Inn Fields, London, W.C., Agent for the Applicants.