IMPROVEMENT IN DYNAMO-ELECTRIC MACHINES
Year: 1884

page_text: "
I, ALBERT SPÖREL, Manufacturer, of Breslau, Germany, do hereby declare the
nature of said Invention for "IMPROVEMENT IN DYNAMO-ELECTRIC MACHINES
to be as follows:-
My invention has for its object to construct a simple dynamo-electric machino by
utilizing the "Foucault," currents generated in a copper disc when turned in front
of the poles of a magnet.
For this purpose I form a disc by winding on two symmetrically placed cores a
flat copper wire and encircling them by a hoop.
The cores are preferably made of vulcanite and have the shape of segments placed
diametrically opposite each other and rounded at their corners. The wire is first
wound on one of the cores, so as to form a flat spiral, then led to the other core and
wound so as to form on the same a second spiral of the same size and shape, and
finally the right and left'spiral are secured together by a circular hoop.
Instead of two, any suitable larger number of spirals may be used to form
& disc.
The disc is mounted on a horizontal shaft and between two frames or stands
carrying a pair of horse-shoe magnets.
The said magnets are placed parallel to each other at equal distances from the
axis of the disc and so that the disc rotates between the poles of each magnet.
The magnets are preferably composed of steel wires arranged in superposed
layers and held in front by shoes. To the inside of each horse shoe magnet and
concentrically with the disc is attached a pair of segments of sufficient size to
periodically overlap the core of every spiral during the revolution of the latter.
The right and left face of the disc nearly touches the inner face of the said
segments or pol-pieces.
On the shaft of the disc is mounted a commutator consisting either of a divided
ring or of two parallel rings and of brushes connected with the two ends of the
copper wire forming the spirals,
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page_text: COMPLETE SPECIFICATION.
I, ALBERT SPÖREL, Manufacturer, of Breslau, Germany, do hereby declare the
nature of my invention for IMPROVEMENT IN DYNAMO-ELECTRIC MACHINES, and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
My invention relates to electric-generators, also called dynamo-electric or 1
magneto-electric machines.
In describing the invention, reference will be made to the annexed drawing
representing the apparatus embodying my invention, and in which Fig. 1 represents
a cross-section, Fig. 2 a plan and Fig. 3 a side view of the dynamo-electric or
magneto-electric generator, while Fig. 4 represents a steel (or electro) magnet,
serving as a field-magnet, Fig. 5 a diametrical section, and Fig. 6 a cross section of
the armature; Fig. 7 represents a commutator with brushes. If a copper disc
rotates around its axis between two opposite magnets, electric currents, known as
"Foucault" currents, are produced.
These currents could hitherto not be utilized with advantage, owing to the
formation of circuit currents. This invention has for its object to induce electric
currents in a wire wound in spiral shape, so as to form a disc i (Figs 5 and 6), the
spiral lines of which are similar to those of "Foucault" currents, by placing the
disc between two opposite poles of magnets and setting the disc in rotary motion,
and to utilize the currents thus generated.
The disc i, Fig³ 5 and 6, consists of two or more spirals formed by a flat, covered,
copper wire of rectangular cross section.
The centre of the spirals remains free, or, if convenient for the formation of the
spirals, it may consist of a core of hard india-rubber. The spirals are so wound
and connected with each other, that only one current is generated in the same.
The spirals are held together by a ring a and made fast to the axle e by means of
three discs b, c, d.
The discs b and d are mounted on the shaft e by groove and feather.
The disc c is mounted loosely and pressed against the spirals by 4 set-screws f.
Fig 1 to 3 show the disc i, constructed as above described, mounted in an iron
frame o and closely surrounded below and above with a horso shoe shaped steel or
electro-magnet g and h.
As shown in Fig. 4, (section A-B) each of the two horse shoe magnets g and h
Fig. 4 may be formed by a number of horse shoe shaped steel wires placed in
layers over each other and fixed with their ends in the shoes k. Each shoe k
carries on the inner side a segment 1, which is so arranged that the two spirals
cover each disc twice during every revolution of the disc i.
• The segment / may, however, bo so enlarged towards the periphery of the disc i,
that the greatest part or the whole of the wires of the disc i are covered on both
sides, by the enlarged segment l' indicated in Fig. 3 by dotted lines.
The poles of the two magnets g and h are of opposite electrical polarity.
The clearance between the two arms of the horse shoe shaped magnets is so
narrow that the disc i has just sufficient play to rotate,

page_text: The axle e also carries the divided commutator ring m in contact with drag
springs or brushes m' (Fig 1 and 7) and the driving pulley n.
According as the two ends of the spirals are connected with two rings and drag-.
springs, alternate or continuous currents are generated.
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
1-A dynamo-electric or magneto-electric disc-machine characterised by the
disc i, consisting of coils, substantially as described.
2-The disc i, consisting principally of two or more copper coils, whose convolu-
tions are similar to the path of Foucault's currents.