Year: 1887

page_text: I, CARL COERPER, of Ehrenfeld, near Cologne o/Rhine, Germany, 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 commutators for electric generators and is designed
to provide means whereby continuous current machines can be used to give off
alternating currents, or whereby alternating currents can be used for the transmission
of power or can be transformned or converted into continuous currents.
In order to use continuous current machines to give off alternating currents the
following device is employed.
In the accompanying drawing the current collector a of a two-pole continuous
current machine is represented. It is assumed that the brushes b, 6 commutate the
magnetic field of the machine in parallel with the armature, that is to say, a shunt
machine for a continuous current is concerned.
Now, two opposite strips of the current collector are conductively connected with
two insulated sliding rings that turn with the machine, in the present case the strip c
with the insulated ring d, and the stripe with the insulated ring f. If a machine
thus commutated is driven, the two sliding springs or brushes g and h, send alternating
currents into the external circuit.
In multipolar machines all the armature coils that have like position with regard to
magnetic fields of like polarity must be conductively connected with each other, either
by a conductive connection of the respective coils themselves or of their conducting
wires passing to the current collector or the corresponding strip of the latter.
A machine thus commutated can accordingly be used not only to give off alternating
currents from the sliding springs g and h, but also to produce a continuous current
from the brushes b, b.
By the arrangement of a somewhat different commutator, series machines and
compound machines can also be used for like purposes.

page_text: In order to use alternating currents for the transmission of power and to trans-
form or convert alternating currents into a continuous current, I employ a similar
arrangement of the machine to that hereinbefore described.
If to a continuous current machine provided with the above described commutator
alternating currents are conducted by means of the sliding springs g and h, it
commences to turn slowly whilst the inlet of current is at a minimum by reason
of the counter electromotive force due to the masses of iron in the machine. The
number of revolutions of the machine, however, increases very rapidly, and with it
the inlet of current until the velocity of rotation of the machine has reached the
proper proportion relatively to the changes of current of the alternating currents.
A four-pole machine for instance makes 1000 revolutions if alternating currents
of 4000 impulses a minute are conducted to it, and so forth.
When the machine has reached its normal number of revolutions, it has in its
armature as well as in its magnetic field a continuous current. It can therefore
be used, not only for the transmission of power by means of alternating currents but
also for the working of continuous current lamps and for galvanic purposes.
Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed I declare that what I claim is,
First The adaptation of continuous current machines for giving off alternating
currents by means of a commutator consisting of two insulated sliding rings (d and f)
turning with the machine and conductively connected with two opposite strips
(c and e) of the current collector (a) of the continuous current machine.
Second-The above described method of providing for the. transmission of power
by alternating currents through the medium of the commutator, of a continuous
current machine substantially as described.
Third The transformation or conversion of alternating currents into continuous
currents by means of a commutator substantially as described.
Dated this 28th day of May 1887
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.