Year: 1887

page_text: Date of Application, 19th Jan., 1887
Complete Left, 16th Nov., 1887
Complete Accepted, 19th Jan., 1888
I, MORITZ IMMISCH, of 119 Torriano Avenue, Camden Town, London, in the
County of Middlesex, Electrician, do hereby declare the nature of this invention to
be as follows:-
This invention has for its object the conversion of alternating currents into
continuous currents of any desired tension. For this purpose I use a primary
conductor through which the alternating current from a generator passes and which
is surrounded by a number of other secondary conductors in which induction takes
place.
The inner end of each of the secondary conductors is connected to a brush and the
outer end of each to another brush, each of such brushes resting on a hub connected
to a separate series of commutator segments, the two series being arranged alternately
in a circular form and insulated from each other. The brushes thus serve to convey
the alternating currents induced in the secondary conductors to the commutator
segments, the number of which in the two series together is double that of the
number of secondary conductors.
On each of the two series of commutator segments rest a number of brushes
corresponding to the number of segments, the brushes belonging to each of the series
being all in metallic connection and serving to convey the induced current away.
To render these currents continuous it is necessary that the commutator should
shift to the extent of one segment for each change of direction in the secondary
current, or what is the same thing synchronously with the phases of the primary
current, so that the set of brushes which previously rested on one series of commutator
segments shall now rest on the other series.
To effect the synchronous movement of the commutator I employ part of the
primary current to actuate an electro motor in which the impulses of attraction
correspond with the impulses in the primary circuit.
It is well known that two alternating current machines will move synchronously
when one acts as a generator and drives the other as a motor. They will do this

page_text: within certain limits even if the motor has to do certain work. I make use of this
well known fact to construct a motor which I employ for shifting the commutator,
and as the motor has nothing to do but to overcome the friction of the brushes on the
commutator the current necessary for this need only be a very small fraction of the
whole.
Instead of shifting the commutator it will be understood that the brushes might be
shifted while the commutator remains stationary.
The above arrangements might be employed either for converting alternating
currents of high tension into continuous currents of low tension, or alternating
currents of low tension into continuous currents of high tension.
There are a number of arrangements already known which serve to convert
alternating currents of one tension into alternating currents of a different tension.
Any of these as far as the particular way is concerned in which the secondary
circuit is brought into close proximity with the primary circuit will do for my
purpose, and it is immaterial in what way the iron employed to assist induction is
distributed; the best converter of alternating currents into alternating currents of a
different tension will also give the best results when applied to converting alternating
currents into continuous ones, according to my invention.
Dated this 19th day of January 1887.
ALLISON BROS.,
Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
3
Apparatus for Converting Alternating Currents into
Continuous Ones.
I, MORITZ IMMISCH, of 119 Torriano Avenue, Camden Town, London, in the
County of Middlesex, Electrician, 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 has for its object the conversion of alternating currents into
continuous currents (that is to say, into intermittent currents in the same direction) of
any desired tension. For this purpose I use a primary conductor through which the
alternating current from a generator passes, and which is surrounded by a number of
other secondary conductors in which induction takes place.
The inner end of each of the secondary conductors is connected to a brush and tho
outer end of each to another brush, each of such brushes resting on a hub connected
to a separate series of commutator segments, the two series being arranged alternately
in a circular form, so as to fit into each other comb-like, and are insulated from each
other. The brushes thus serve to convey the alternating currents induced in the
secondary conductors to the commutator segments. Instead of brushes, bands or
stirrups encircling the hubs may be employed, so as to give increased contact
surfaces.
On each of the two series of commutator segnients rest a number of brushes, the
brushes belonging to each of the series being all in metallic connection and serving to
convey the induced current away.
It is preferable to use as many brushes as there are segments in the two series, as it
provides an increased number of points of contact for collecting the continuous
current, which is necessary when it is required to convert alternating currents
of high tension into continuous currents of low tension, but when the reverse is the
case the number of brushes may be reduced.
In order to render the alternating induced currents continuous it is necessary that
the commutator should shift to the extent of one segment for each change of direction
in the secondary current, or what is the same thing synchronously with the phases of
the primary current, so that the set of brushes which previously rested on one series
of commutator segments shall now rest on the other series. This commutation takes
place at the point of no potential and precludes all possibility of sparking.
To effect the synchronous movement of the commutator I employ part of the
primary current to actuate an electro motor in which the impulses of attraction
correspond with the phases of the primary current.
It is well known that two alternating current machines will move synchronously
when one acts as a generator and drives the other as a motor. They will do this
within certain limits even if the motor has to do certain work. I make use of this

page_text: well known fact to construct a motor which I employ for shifting the commutator,
and as the motor has nothing to do but to overcome the friction of the brushes on the
commutator, the current necessary for this will only be a very small fraction of the
whole.
Instead of shifting the commutator it will readily be understood that the brushes
might be shifted while the commutator remains stationary ; and further, instead of
leading the currents induced in the secondary conductors to the segments and
collecting the continuous current from the brushes, the operation may be reversed.
The above arrangements might be employed either for converting alternating
currents of high tension into continuous currents of low tension, or alternating
currents of low-tension into continuous currents of high tension.
There are a number of arrangements already known which serve to convert
alternating currents of one tension into alternating currents of a different tension.
Any of these (as far as the particular way in which the secondary circuit is brought
into close proximity with the primary circuit is concerned), will do for my purpose,
and it is immaterial in what way the iron employed to assist induction is distributed
the best converter of alternating currents into alternating currents of a different
tension will also give the best results when applied to converting alternating currents
into continuous ones according to my invention.
My invention is illustrated diagrammatically in the accompanying drawing, in
which
Fig. 1 is an elevation showing the arrangement of commutator segments, brushes
and collectors.
Fig. 2 is a plan view of same opened out or developed, and
Fig. 3 is a plan view of the general arrangement, showing the motor.
;
I have shown the commutator as being formed with three segments in each series,
those marked a being connected together and forming one series, and those marked b
being connected together and forming the other series.
The brushes are marked c and d, and these as shown (like the segments a and b)
alternate, all the c brushes being connected together, and all the brushes connected
together.
a is the hub common to all the a segments, and upon which rests a brush or
stirrup e, while b' is the hub common to all the 6 segments, and upon which rests a
brush or stirrup f.
In Fig. 3, M is the motor, and the commutator above described is shown as applied
directly to its spindle.
This motor is preferably of the form described in the specification of my prior
Patent No. 4665 dated 30th September 1882, as such form will give distinct impulses
instead of a continuous pull as would occur in machines of the Gramme type. The
cores of the motor are preferably laminated to a high degree so as to enable the
changes of polarity to readily follow the phases of the alternating current. The
motor should only be of such a strength as to comfortably overcome the friction
of its bearings and the brushes, in order not to use more electric energy than is
really necessary.
Part of the alternating current is led to the motor through its own commutator
proper m, and as the commutator of the transformer is mounted on its spindle, the
movement of the motor will be transmitted thereto, and in this case the total number
of segments in the two series thereof must be equal to the number of impulses of
the motor per revolution.
The alternating current passes through the primary wire of an induction coil and
thus induces a current in the secondary wire or wires thereof, the ends of which are
connected either to the brushes a and b, or to the brushes e and, of the transformer.
The secondary wires of the induction coil may be all connected to a switch so as
to enable them to be placed more or less in parallel, for the purpose of varying the
A suitable switch is also provided for putting the tran-foriner in or out of
action. The construction of switches for effecting both the above purposes will
readily suggest themselves to any practical electrician.
current.

page_text: In the case where the induced current is led to the brushes e, f, the continuous
current will be taken off by the brushes a, b, and vice versa.
Instead of mounting the transformer directly upon the motor spindle, it may bo
driven from its spindle by suitable gearing at a different speed to the motor, all
that is necessary being that the number of impulses per unit of time in the motor
should correspond to the number of changes in the commutator.
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
The means for converting alternating currents into continuous currents, consisting
in including a motor and also an induction coil in the circuit of the generator, the
secondary current from such induction coil being conveyed to one part of a com-
mutator while the continuous current is collected from the other part thereof, such
commutator being composed of two sets of segments arranged alternately and the
segments of each set connected together, and two sets of brushes resting on such
segments and also arranged alternately, those of each set being connected together,
while a pair of brushes is provided, each one thereof being caused to bear on one of
the hubs connecting each set of commutator segments, either the segments or the two
sets of brushes resting thereon being actuated by the motor so as to shift same to the
required extent in unison therewith, all substantially as specified.
Dated this 14th day of November 1887.
ALLISON BROS.,
Agents for the Applicant.
ALLISON BROS.,
Agents for the Applicant.