A MAGNETO- ELECTRIC MACHINE
Year: 1881

page_text: LETTERS PATENT to Frederik Wolff, of the International Patent Office,
Copenhagen, Denınark, Patent Agent, for an Invention of "A MAGNETO-
ELECTRIC MACHINE." A communication by Professor Christopher Peter
Jürgensen and Dr. Phil Professor Ludvig Valentin 'Lorenz, both of
Copenhagen, Denmark,
PROVISIONAL SPECIFICATION left by the said Frederik Wolff at the
Office of the Commissioners of Patents on the 1st June 1881.
FREDERIK WOLFF, of the International Patent Office, Copenhagen, Denmark,
Patent Agent. "A MAGNETO-ELECTRIC MACHINE." (A communication by
Professor Christopher Peter Jürgensen and Dr. Phil Professor Ludvig Valentin
Lorenz, both of Copenhagen, Denmark.)
This magneto-electric machine possesses generally speaking inore electromotive
power than any of the heretofore known machines acting on similar principles,
and the total resistance of conduction in the machine is at the same time very
insignificant. The weight and dimensions of the machine are also small, having
regard to the power of production.
The machine is on the whole similar to the Gramme machine. It has hence an
outer electro magnet, an annular armature having wire coil sections and rotating
between the poles of the electro magnet, a contact cylinder at one end, and
brushes for collecting the electric current developed. The powerful action of the
machine is mainly attained by the application of a central electro magnet inside
the annular armature; this electro magnet is, so to say, formed as two bar magnets
placed crosswise, and having the north poles as well as the south poles respectively
united by pole piece; this interior electro magnet has a central gudgeon which fits
in a standard or bracket and is held therein by screws, so that the north pole and
south pole of the inner electro magnet are opposite the north pole and south pole
of the outer electromagnet respectively.
In order to further steady or secure the armature in its bearing in spite of the
interior electro magnet, there are unmagnetic rings secured by studs projecting from
the armature; of these rings one has a central annular steel boss or ring which

page_text: fits freely round the gudgeon and has a projection which works in the bearing, and
the other ring is fast on the spindle whereby the armature is revolved, and which
consequently has a driving strap pulley. The armature is divided into a number
of rings arranged side by side, separated from each other by insulating pieces, the
whole being held together by bolts placed midways between the aforesaid studs.
By this arrangement induction currents in the armature are prevented in the
length direction parallel to the axis; hereby is also attained that very long
armatures (that is, in the axial direction) may be used in combination with one or
more outer electro-magnets whereby the power of the machine may be greatly
increased.
In order to prevent damage to the insulating pieces on the wire coils and in the
armature itself by too great heat produced therein during the working of the
machine through the unpreventable resistance to conduction, the spokes which
unite the ring at the gudgeon end with its boss or nave are chamfered off on the
edges, and may also have little wings, so that by the revolution of the armature
an air current into the armature may be produced in its length direction.
The outer electro magnet of the machine really consists of two electro magnets,
which by the bed plate of the machine are united to a single horse shoe shaped
electro magnet. To prevent hurtful vibration of these two pole parts they are
stendied against each other at the top by an unmagnetic intermediate piece or
.plate screwed thereto, and below by unmagnetic columns. In order to obtain the
most powerful magnetism with the least conduction resistance, the wire coils are
accumulated to the greatest extent near the pole pieces of the electro magnet.
The electric current to the inner and to the outer electro magnet may either be
taken from the main current of the machine itself or from a less number of separate
wire sections on the armature of the machine, or from another smaller electro
magnetic machine. The contact cylinder or commutator consists of angle shaped
copper bars, which by a disc or ring are fastened to the ring which is fast on the
spindle, but of course with insulating pieces between the said bars and the ring
and its centre boss, and the disc. The collecting brushes are of the usual form.
They are arranged on the spindle bearing bracket, so that they by being turned
round the centre line of the spindle may be set according to the neutral axis of the
machine.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Frederik Wolff in the Great Seal Patent Office on the 1st December
1881.
FREDERIK WOLFF, of the International Patent Office, Copenhagen, Denmark,
Patent Agent. "A MAGNETO-ELECTRIC MACHINE." (A communication from
Professor Christopher Peter Jürgensen and Dr. Phil Professor Ludvig Valentin
Lorenz, both of Copenhagen, Denmark.)
This magneto-electric machine possesses generally speaking more electromotive
power than any of the heretofore known machines acting on similar principles, and
the total resistance of conduction in the machine is at the same time very
insignificant. The weight and dimensions of the machine are also small, having
regard to the power of production.
In the accompanying Drawings, Figure 1 is an end view; Figure 2, a vertical
longitudinal section; and Figure 3, a detail view of a magneto-electric machine
constructed according to this Invention.
The machine is on the whole similar to the Gramme machine. It has hence
an outer electro-magnet a¹, a², a³, an annular armature b' having wire coil sections b*,
and rotating between the poles of the electro-magnet a contact cylinder c at one
end, and brushes for collecting the electric current developed. The powerful
action of the machine is mainly attained by the application of a central electro-
magnet inside the annular armaturo b', b; this electro-magnet is, so to say,
formed as two bar magnets placed crosswise, and having the north poles as well as
the south poles respectively united by pole piece; this interior electro-magnet has
a central gudgeon e which fits in a standard or bracket and is held therein by
screws, which however are not shown on the Drawing, so that the north pole and
south pole of the inner electro-magnet are opposite the north pole and south pole
of the outer electro-magnet respectively.
In order to further steady or secure the armature in its bearing in spite of the
interior electro-magnet, there are unmagnetic rings g', g, secured by studs pro-
jecting from the armature b'; of these rings one g₁ has a central annular steel boss
or ring which fits freely round the gudgeon e, and has a projection n which works
in the bearing m¹, and the other ring is fast on the spindle h, whereby the
armature is revolved and which consequently has a driving strap pulley i. The
armature b' is divided into a number of rings arranged side by side, separated from
each other by insulating pieces, the whole being held together by bolts placed
midways between the aforesaid studs 6. By this arrangement induction currents
in the armature bare prevented in the length direction parallel to the axis;
hereby is also attained that very long armatures (that is, in the axial direction)
may be used in combination with one or more outer electro-magnets, whereby the
power of the machine may be greatly increased.
In order to prevent dainage to the insulating pieces on the wire coils &* and in
the armature b¹ itself by too great heat produced therein during the working of the
machine through the unpreventable resistance to conduction, the spokes which
unite the ring g' at the gudgeon end with its boss or nave are chamfered off on the
edges, and may also have little wings ³, as shown in Figure 3, so that by tho
revolution of the armature a cooling air current into the armaturo may be produced
in its length direction.
The outer electro-magnet of the machine really consists of two electro-magnets a¹
and a', which by the iron bed plate of the machine are united to a single horse-
shoe-shaped electro-magnet. To prevent hurtful vibration of these two pole parts a'
and a³, they are steadied against each other at the top by an unmagnetic inter-
mediate piece or plate p screwed thereto, and below by unmaguetic columns 7. In

page_text: order to obtain the most powerful magnetism with the least conduction resistance,
the wire coils are accumulated to the greatest extent near the pole pieces of the
electro-magnet.
The electric current to the inner and to the outer electro-magnet inay either bo
taken from the main current of the machine itself or from a less number of
separate wire sections on the armature of the machine, or, lastly, from another
smaller electro-magnetic machine. The contact cylinder c or commutator consists
of angle shaped copper bars, which by a disc or ring j are fastened to the ring g
which is fast on the spindle h, but of course with insulating pieces between the
said bars and the ring and its centre boss, and the disc j. The collecting
brushes are not shown on the Drawings as they are of the usual form. They are
arranged on the spindle bearing bracket &, so that they by being turned round the
centre line of the spindle may be set according to the neutral axis of the machine.
And having thus described and ascertained the nature of this Invention and the
manner of carrying the saine into effect as communicated to me, I declare that I
claim,―
h
First. In magneto-electric or electro-magnetic machines the application of an
electro-magnet within the annular rotating armature, cither alone or in combination
with outer electro-magnets, ns set forth.
Second. In magneto-electric or electro-magnetic machines the application of
annular armatures, the iron core of which consists of rings that are held together
by studs across the rings or along the armature, and are insulated from each other
by intermediate insulating layers, as set forth.
Third. In magneto-electric machines the arrangement of parts whereby an air
current produced by the motion of the machine is applied to the absorption of the
heat which is evolved during the motion of the machine, as set forth.
Fourth. In electro-magnetic machines the application of outer electro-magnets of
the special construction shown and described.
Fifth. The combination of parts forming the new or improved machine for
producing electricity, all substantially as described, and also as specially shown in
the accompanying Drawings.
In witness whereof, ], the said Frederik Wolff, have hereunto set my hand
and seal, this Twenty-fifth day of November, in the year of our Lord One
thousand eight hundred and eighty-one.